+#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <assert.h>
-#include <winsock.h>
#include "putty.h"
#include "tree234.h"
#include "ssh.h"
-#include "scp.h"
#ifndef FALSE
#define FALSE 0
#endif
#define logevent(s) { logevent(s); \
- if (!(flags & FLAG_CONNECTION) && (flags & FLAG_VERBOSE)) \
- fprintf(stderr, "%s\n", s); }
-
-#define SSH1_MSG_DISCONNECT 1
-#define SSH1_SMSG_PUBLIC_KEY 2
-#define SSH1_CMSG_SESSION_KEY 3
-#define SSH1_CMSG_USER 4
-#define SSH1_CMSG_AUTH_RSA 6
-#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7
-#define SSH1_CMSG_AUTH_RSA_RESPONSE 8
-#define SSH1_CMSG_AUTH_PASSWORD 9
-#define SSH1_CMSG_REQUEST_PTY 10
-#define SSH1_CMSG_WINDOW_SIZE 11
-#define SSH1_CMSG_EXEC_SHELL 12
-#define SSH1_CMSG_EXEC_CMD 13
-#define SSH1_SMSG_SUCCESS 14
-#define SSH1_SMSG_FAILURE 15
-#define SSH1_CMSG_STDIN_DATA 16
-#define SSH1_SMSG_STDOUT_DATA 17
-#define SSH1_SMSG_STDERR_DATA 18
-#define SSH1_CMSG_EOF 19
-#define SSH1_SMSG_EXIT_STATUS 20
-#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21
-#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22
-#define SSH1_MSG_CHANNEL_DATA 23
-#define SSH1_MSG_CHANNEL_CLOSE 24
-#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25
-#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30
-#define SSH1_SMSG_AGENT_OPEN 31
-#define SSH1_CMSG_EXIT_CONFIRMATION 33
-#define SSH1_MSG_IGNORE 32
-#define SSH1_MSG_DEBUG 36
-#define SSH1_CMSG_AUTH_TIS 39
-#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40
-#define SSH1_CMSG_AUTH_TIS_RESPONSE 41
-#define SSH1_CMSG_AUTH_CCARD 70
-#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71
-#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72
-
-#define SSH1_AUTH_TIS 5
-#define SSH1_AUTH_CCARD 16
-
-#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1
-#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2
-#define SSH_AGENTC_RSA_CHALLENGE 3
-#define SSH_AGENT_RSA_RESPONSE 4
-#define SSH_AGENT_FAILURE 5
-#define SSH_AGENT_SUCCESS 6
-#define SSH_AGENTC_ADD_RSA_IDENTITY 7
-#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8
-
-#define SSH2_MSG_DISCONNECT 1
-#define SSH2_MSG_IGNORE 2
-#define SSH2_MSG_UNIMPLEMENTED 3
-#define SSH2_MSG_DEBUG 4
-#define SSH2_MSG_SERVICE_REQUEST 5
-#define SSH2_MSG_SERVICE_ACCEPT 6
-#define SSH2_MSG_KEXINIT 20
-#define SSH2_MSG_NEWKEYS 21
-#define SSH2_MSG_KEXDH_INIT 30
-#define SSH2_MSG_KEXDH_REPLY 31
-#define SSH2_MSG_USERAUTH_REQUEST 50
-#define SSH2_MSG_USERAUTH_FAILURE 51
-#define SSH2_MSG_USERAUTH_SUCCESS 52
-#define SSH2_MSG_USERAUTH_BANNER 53
-#define SSH2_MSG_USERAUTH_PK_OK 60
-#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60
-#define SSH2_MSG_GLOBAL_REQUEST 80
-#define SSH2_MSG_REQUEST_SUCCESS 81
-#define SSH2_MSG_REQUEST_FAILURE 82
-#define SSH2_MSG_CHANNEL_OPEN 90
-#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91
-#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92
-#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93
-#define SSH2_MSG_CHANNEL_DATA 94
-#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95
-#define SSH2_MSG_CHANNEL_EOF 96
-#define SSH2_MSG_CHANNEL_CLOSE 97
-#define SSH2_MSG_CHANNEL_REQUEST 98
-#define SSH2_MSG_CHANNEL_SUCCESS 99
-#define SSH2_MSG_CHANNEL_FAILURE 100
-
-#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1
-#define SSH2_OPEN_CONNECT_FAILED 2
-#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3
-#define SSH2_OPEN_RESOURCE_SHORTAGE 4
-#define SSH2_EXTENDED_DATA_STDERR 1
+ if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
+ { fprintf(stderr, "%s\n", s); fflush(stderr); } }
+
+#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
+ (s ? sk_close(s), s = NULL : 0), \
+ connection_fatal msg )
+
+#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
+#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
+#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
+#define SSH1_CMSG_USER 4 /* 0x4 */
+#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
+#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
+#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
+#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
+#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
+#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
+#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
+#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
+#define SSH1_SMSG_SUCCESS 14 /* 0xe */
+#define SSH1_SMSG_FAILURE 15 /* 0xf */
+#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
+#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
+#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
+#define SSH1_CMSG_EOF 19 /* 0x13 */
+#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
+#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
+#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
+#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
+#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
+#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
+#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
+#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
+#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
+#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
+#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
+#define SSH1_MSG_IGNORE 32 /* 0x20 */
+#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
+#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
+#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
+#define SSH1_MSG_DEBUG 36 /* 0x24 */
+#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
+#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
+#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
+#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
+#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
+#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
+#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
+
+#define SSH1_AUTH_TIS 5 /* 0x5 */
+#define SSH1_AUTH_CCARD 16 /* 0x10 */
+
+#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
+/* Mask for protoflags we will echo back to server if seen */
+#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
+
+#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
+#define SSH2_MSG_IGNORE 2 /* 0x2 */
+#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
+#define SSH2_MSG_DEBUG 4 /* 0x4 */
+#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
+#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
+#define SSH2_MSG_KEXINIT 20 /* 0x14 */
+#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
+#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
+#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
+#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
+#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
+#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
+#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
+#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
+#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
+#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
+#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
+#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
+#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
+#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
+#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
+#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
+#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
+#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
+#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
+#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
+#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
+#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
+#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
+#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
+#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
+#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
+#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
+#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
+#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
+
+/*
+ * Packet type contexts, so that ssh2_pkt_type can correctly decode
+ * the ambiguous type numbers back into the correct type strings.
+ */
+#define SSH2_PKTCTX_DHGROUP1 0x0001
+#define SSH2_PKTCTX_DHGEX 0x0002
+#define SSH2_PKTCTX_PUBLICKEY 0x0010
+#define SSH2_PKTCTX_PASSWORD 0x0020
+#define SSH2_PKTCTX_KBDINTER 0x0040
+#define SSH2_PKTCTX_AUTH_MASK 0x00F0
+
+#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
+#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
+#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
+#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
+#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
+#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
+#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
+#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
+#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
+#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
+#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
+#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
+#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
+#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
+#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
+
+static const char *const ssh2_disconnect_reasons[] = {
+ NULL,
+ "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
+ "SSH_DISCONNECT_PROTOCOL_ERROR",
+ "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
+ "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
+ "SSH_DISCONNECT_MAC_ERROR",
+ "SSH_DISCONNECT_COMPRESSION_ERROR",
+ "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
+ "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
+ "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
+ "SSH_DISCONNECT_CONNECTION_LOST",
+ "SSH_DISCONNECT_BY_APPLICATION",
+ "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
+ "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
+ "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
+ "SSH_DISCONNECT_ILLEGAL_USER_NAME",
+};
+
+#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
+#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
+#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
+#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
+
+#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
+
+/*
+ * Various remote-bug flags.
+ */
+#define BUG_CHOKES_ON_SSH1_IGNORE 1
+#define BUG_SSH2_HMAC 2
+#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
+#define BUG_CHOKES_ON_RSA 8
+
+static int ssh_pkt_ctx = 0;
+
+#define translate(x) if (type == x) return #x
+#define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
+char *ssh1_pkt_type(int type)
+{
+ translate(SSH1_MSG_DISCONNECT);
+ translate(SSH1_SMSG_PUBLIC_KEY);
+ translate(SSH1_CMSG_SESSION_KEY);
+ translate(SSH1_CMSG_USER);
+ translate(SSH1_CMSG_AUTH_RSA);
+ translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
+ translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
+ translate(SSH1_CMSG_AUTH_PASSWORD);
+ translate(SSH1_CMSG_REQUEST_PTY);
+ translate(SSH1_CMSG_WINDOW_SIZE);
+ translate(SSH1_CMSG_EXEC_SHELL);
+ translate(SSH1_CMSG_EXEC_CMD);
+ translate(SSH1_SMSG_SUCCESS);
+ translate(SSH1_SMSG_FAILURE);
+ translate(SSH1_CMSG_STDIN_DATA);
+ translate(SSH1_SMSG_STDOUT_DATA);
+ translate(SSH1_SMSG_STDERR_DATA);
+ translate(SSH1_CMSG_EOF);
+ translate(SSH1_SMSG_EXIT_STATUS);
+ translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
+ translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
+ translate(SSH1_MSG_CHANNEL_DATA);
+ translate(SSH1_MSG_CHANNEL_CLOSE);
+ translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
+ translate(SSH1_SMSG_X11_OPEN);
+ translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
+ translate(SSH1_MSG_PORT_OPEN);
+ translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
+ translate(SSH1_SMSG_AGENT_OPEN);
+ translate(SSH1_MSG_IGNORE);
+ translate(SSH1_CMSG_EXIT_CONFIRMATION);
+ translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
+ translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
+ translate(SSH1_MSG_DEBUG);
+ translate(SSH1_CMSG_REQUEST_COMPRESSION);
+ translate(SSH1_CMSG_AUTH_TIS);
+ translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
+ translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
+ translate(SSH1_CMSG_AUTH_CCARD);
+ translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
+ translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
+ return "unknown";
+}
+char *ssh2_pkt_type(int type)
+{
+ translate(SSH2_MSG_DISCONNECT);
+ translate(SSH2_MSG_IGNORE);
+ translate(SSH2_MSG_UNIMPLEMENTED);
+ translate(SSH2_MSG_DEBUG);
+ translate(SSH2_MSG_SERVICE_REQUEST);
+ translate(SSH2_MSG_SERVICE_ACCEPT);
+ translate(SSH2_MSG_KEXINIT);
+ translate(SSH2_MSG_NEWKEYS);
+ translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
+ translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
+ translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
+ translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
+ translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
+ translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
+ translate(SSH2_MSG_USERAUTH_REQUEST);
+ translate(SSH2_MSG_USERAUTH_FAILURE);
+ translate(SSH2_MSG_USERAUTH_SUCCESS);
+ translate(SSH2_MSG_USERAUTH_BANNER);
+ translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
+ translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
+ translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
+ translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
+ translate(SSH2_MSG_GLOBAL_REQUEST);
+ translate(SSH2_MSG_REQUEST_SUCCESS);
+ translate(SSH2_MSG_REQUEST_FAILURE);
+ translate(SSH2_MSG_CHANNEL_OPEN);
+ translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
+ translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
+ translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ translate(SSH2_MSG_CHANNEL_DATA);
+ translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
+ translate(SSH2_MSG_CHANNEL_EOF);
+ translate(SSH2_MSG_CHANNEL_CLOSE);
+ translate(SSH2_MSG_CHANNEL_REQUEST);
+ translate(SSH2_MSG_CHANNEL_SUCCESS);
+ translate(SSH2_MSG_CHANNEL_FAILURE);
+ return "unknown";
+}
+#undef translate
+#undef translatec
#define GET_32BIT(cp) \
(((unsigned long)(unsigned char)(cp)[0] << 24) | \
#define crWaitUntil(c) do { crReturn(0); } while (!(c))
#define crWaitUntilV(c) do { crReturnV; } while (!(c))
-extern struct ssh_cipher ssh_3des;
-extern struct ssh_cipher ssh_3des_ssh2;
-extern struct ssh_cipher ssh_des;
-extern struct ssh_cipher ssh_blowfish;
-
-/* for ssh 2; we miss out single-DES because it isn't supported */
-struct ssh_cipher *ciphers[] = { &ssh_3des_ssh2, &ssh_blowfish };
+extern char *x11_init(Socket *, char *, void *);
+extern void x11_close(Socket);
+extern int x11_send(Socket, char *, int);
+extern void x11_invent_auth(char *, int, char *, int);
+extern void x11_unthrottle(Socket s);
+extern void x11_override_throttle(Socket s, int enable);
+
+extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
+extern char *pfd_addforward(char *desthost, int destport, int port);
+extern void pfd_close(Socket s);
+extern int pfd_send(Socket s, char *data, int len);
+extern void pfd_confirm(Socket s);
+extern void pfd_unthrottle(Socket s);
+extern void pfd_override_throttle(Socket s, int enable);
+
+static void ssh2_pkt_init(int pkt_type);
+static void ssh2_pkt_addbool(unsigned char value);
+static void ssh2_pkt_adduint32(unsigned long value);
+static void ssh2_pkt_addstring_start(void);
+static void ssh2_pkt_addstring_str(char *data);
+static void ssh2_pkt_addstring_data(char *data, int len);
+static void ssh2_pkt_addstring(char *data);
+static char *ssh2_mpint_fmt(Bignum b, int *len);
+static void ssh2_pkt_addmp(Bignum b);
+static int ssh2_pkt_construct(void);
+static void ssh2_pkt_send(void);
-extern struct ssh_kex ssh_diffiehellman;
-struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
+/*
+ * Buffer management constants. There are several of these for
+ * various different purposes:
+ *
+ * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
+ * on a local data stream before we throttle the whole SSH
+ * connection (in SSH1 only). Throttling the whole connection is
+ * pretty drastic so we set this high in the hope it won't
+ * happen very often.
+ *
+ * - SSH_MAX_BACKLOG is the amount of backlog that must build up
+ * on the SSH connection itself before we defensively throttle
+ * _all_ local data streams. This is pretty drastic too (though
+ * thankfully unlikely in SSH2 since the window mechanism should
+ * ensure that the server never has any need to throttle its end
+ * of the connection), so we set this high as well.
+ *
+ * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
+ * channels.
+ */
-extern struct ssh_hostkey ssh_dss;
-struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
+#define SSH1_BUFFER_LIMIT 32768
+#define SSH_MAX_BACKLOG 32768
+#define OUR_V2_WINSIZE 16384
-extern struct ssh_mac ssh_sha1;
+const static struct ssh_kex *kex_algs[] = {
+ &ssh_diffiehellman_gex,
+ &ssh_diffiehellman
+};
-static SHA_State exhash;
+const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
-static void nullmac_key(unsigned char *key) { }
-static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
-static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
-struct ssh_mac ssh_mac_none = {
+static void nullmac_key(unsigned char *key)
+{
+}
+static void nullmac_generate(unsigned char *blk, int len,
+ unsigned long seq)
+{
+}
+static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
+{
+ return 1;
+}
+const static struct ssh_mac ssh_mac_none = {
nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
};
-struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none };
-
-struct ssh_compress ssh_comp_none = {
- "none"
+const static struct ssh_mac *macs[] = {
+ &ssh_sha1, &ssh_md5, &ssh_mac_none
+};
+const static struct ssh_mac *buggymacs[] = {
+ &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
};
-struct ssh_compress *compressions[] = { &ssh_comp_none };
-
-static SOCKET s = INVALID_SOCKET;
-static unsigned char session_key[32];
-static struct ssh_cipher *cipher = NULL;
-static struct ssh_cipher *cscipher = NULL;
-static struct ssh_cipher *sccipher = NULL;
-static struct ssh_mac *csmac = NULL;
-static struct ssh_mac *scmac = NULL;
-static struct ssh_compress *cscomp = NULL;
-static struct ssh_compress *sccomp = NULL;
-static struct ssh_kex *kex = NULL;
-static struct ssh_hostkey *hostkey = NULL;
-int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
+static void ssh_comp_none_init(void)
+{
+}
+static int ssh_comp_none_block(unsigned char *block, int len,
+ unsigned char **outblock, int *outlen)
+{
+ return 0;
+}
+static int ssh_comp_none_disable(void)
+{
+ return 0;
+}
+const static struct ssh_compress ssh_comp_none = {
+ "none",
+ ssh_comp_none_init, ssh_comp_none_block,
+ ssh_comp_none_init, ssh_comp_none_block,
+ ssh_comp_none_disable
+};
+extern const struct ssh_compress ssh_zlib;
+const static struct ssh_compress *compressions[] = {
+ &ssh_zlib, &ssh_comp_none
+};
-static char *savedhost;
-static int ssh_send_ok;
+enum { /* channel types */
+ CHAN_MAINSESSION,
+ CHAN_X11,
+ CHAN_AGENT,
+ CHAN_SOCKDATA,
+ CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
+};
/*
* 2-3-4 tree storing channels.
*/
struct ssh_channel {
- int remoteid, localid;
+ unsigned remoteid, localid;
int type;
int closes;
union {
- struct ssh_agent_channel {
- unsigned char *message;
- unsigned char msglen[4];
- int lensofar, totallen;
- } a;
+ struct ssh1_data_channel {
+ int throttling;
+ } v1;
+ struct ssh2_data_channel {
+ bufchain outbuffer;
+ unsigned remwindow, remmaxpkt;
+ unsigned locwindow;
+ } v2;
+ } v;
+ union {
+ struct ssh_agent_channel {
+ unsigned char *message;
+ unsigned char msglen[4];
+ int lensofar, totallen;
+ } a;
+ struct ssh_x11_channel {
+ Socket s;
+ } x11;
+ struct ssh_pfd_channel {
+ Socket s;
+ } pfd;
} u;
};
-static tree234 *ssh_channels; /* indexed by local id */
-static int ssh_channelcmp(void *av, void *bv) {
- struct ssh_channel *a = (struct ssh_channel *)av;
- struct ssh_channel *b = (struct ssh_channel *)bv;
- if (a->localid < b->localid) return -1;
- if (a->localid > b->localid) return +1;
- return 0;
-}
-static int ssh_channelfind(void *av, void *bv) {
- int *a = (int *)av;
- struct ssh_channel *b = (struct ssh_channel *)bv;
- if (*a < b->localid) return -1;
- if (*a > b->localid) return +1;
- return 0;
-}
-static enum {
- SSH_STATE_BEFORE_SIZE,
- SSH_STATE_INTERMED,
- SSH_STATE_SESSION,
- SSH_STATE_CLOSED
-} ssh_state = SSH_STATE_BEFORE_SIZE;
-
-static int size_needed = FALSE;
-
-static void s_write (char *buf, int len) {
- while (len > 0) {
- int i = send (s, buf, len, 0);
- noise_ultralight(i);
- if (i <= 0)
- fatalbox("Lost connection while sending");
- if (i > 0)
- len -= i, buf += i;
- }
-}
-
-static int s_read (char *buf, int len) {
- int ret = 0;
- while (len > 0) {
- int i = recv (s, buf, len, 0);
- noise_ultralight(i);
- if (i > 0)
- len -= i, buf += i, ret += i;
- else
- return i;
- }
- return ret;
-}
-
-static void c_write (char *buf, int len) {
- if (!(flags & FLAG_CONNECTION)) {
- int i;
- for (i = 0; i < len; i++)
- if (buf[i] != '\r')
- fputc(buf[i], stderr);
- return;
- }
- while (len--)
- c_write1(*buf++);
-}
+/*
+ * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
+ * 2 use this structure in different ways, reflecting SSH 2's
+ * altogether saner approach to port forwarding.
+ *
+ * In SSH 1, you arrange a remote forwarding by sending the server
+ * the remote port number, and the local destination host:port.
+ * When a connection comes in, the server sends you back that
+ * host:port pair, and you connect to it. This is a ready-made
+ * security hole if you're not on the ball: a malicious server
+ * could send you back _any_ host:port pair, so if you trustingly
+ * connect to the address it gives you then you've just opened the
+ * entire inside of your corporate network just by connecting
+ * through it to a dodgy SSH server. Hence, we must store a list of
+ * host:port pairs we _are_ trying to forward to, and reject a
+ * connection request from the server if it's not in the list.
+ *
+ * In SSH 2, each side of the connection minds its own business and
+ * doesn't send unnecessary information to the other. You arrange a
+ * remote forwarding by sending the server just the remote port
+ * number. When a connection comes in, the server tells you which
+ * of its ports was connected to; and _you_ have to remember what
+ * local host:port pair went with that port number.
+ *
+ * Hence: in SSH 1 this structure stores host:port pairs we intend
+ * to allow connections to, and is indexed by those host:port
+ * pairs. In SSH 2 it stores a mapping from source port to
+ * destination host:port pair, and is indexed by source port.
+ */
+struct ssh_rportfwd {
+ unsigned sport, dport;
+ char dhost[256];
+};
struct Packet {
long length;
long maxlen;
};
+static SHA_State exhash, exhashbase;
+
+static Socket s = NULL;
+
+static unsigned char session_key[32];
+static int ssh1_compressing;
+static int ssh1_remote_protoflags;
+static int ssh1_local_protoflags;
+static int ssh_agentfwd_enabled;
+static int ssh_X11_fwd_enabled;
+static int ssh_remote_bugs;
+static const struct ssh_cipher *cipher = NULL;
+static const struct ssh2_cipher *cscipher = NULL;
+static const struct ssh2_cipher *sccipher = NULL;
+static const struct ssh_mac *csmac = NULL;
+static const struct ssh_mac *scmac = NULL;
+static const struct ssh_compress *cscomp = NULL;
+static const struct ssh_compress *sccomp = NULL;
+static const struct ssh_kex *kex = NULL;
+static const struct ssh_signkey *hostkey = NULL;
+static unsigned char ssh2_session_id[20];
+int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
+ int is_pw) = NULL;
+
+static char *savedhost;
+static int savedport;
+static int ssh_send_ok;
+static int ssh_echoing, ssh_editing;
+
+static tree234 *ssh_channels; /* indexed by local id */
+static struct ssh_channel *mainchan; /* primary session channel */
+static int ssh_exitcode = -1;
+
+static tree234 *ssh_rportfwds;
+
+static enum {
+ SSH_STATE_PREPACKET,
+ SSH_STATE_BEFORE_SIZE,
+ SSH_STATE_INTERMED,
+ SSH_STATE_SESSION,
+ SSH_STATE_CLOSED
+} ssh_state = SSH_STATE_PREPACKET;
+
+static int size_needed = FALSE, eof_needed = FALSE;
+
static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
+static unsigned char *deferred_send_data = NULL;
+static int deferred_len = 0, deferred_size = 0;
+
+/*
+ * Gross hack: pscp will try to start SFTP but fall back to scp1 if
+ * that fails. This variable is the means by which scp.c can reach
+ * into the SSH code and find out which one it got.
+ */
+int ssh_fallback_cmd = 0;
static int ssh_version;
-static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
+static int ssh1_throttle_count;
+static int ssh_overall_bufsize;
+static int ssh_throttled_all;
+static int ssh1_stdout_throttling;
+static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
static void ssh_size(void);
+static void ssh_special(Telnet_Special);
+static int ssh2_try_send(struct ssh_channel *c);
+static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
+ int len);
+static void ssh_throttle_all(int enable, int bufsize);
+static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
+static int (*s_rdpkt) (unsigned char **data, int *datalen);
+static int ssh_sendbuffer(void);
+
+static struct rdpkt1_state_tag {
+ long len, pad, biglen, to_read;
+ unsigned long realcrc, gotcrc;
+ unsigned char *p;
+ int i;
+ int chunk;
+} rdpkt1_state;
+
+static struct rdpkt2_state_tag {
+ long len, pad, payload, packetlen, maclen;
+ int i;
+ int cipherblk;
+ unsigned long incoming_sequence;
+} rdpkt2_state;
+
+static int ssh_channelcmp(void *av, void *bv)
+{
+ struct ssh_channel *a = (struct ssh_channel *) av;
+ struct ssh_channel *b = (struct ssh_channel *) bv;
+ if (a->localid < b->localid)
+ return -1;
+ if (a->localid > b->localid)
+ return +1;
+ return 0;
+}
+static int ssh_channelfind(void *av, void *bv)
+{
+ unsigned *a = (unsigned *) av;
+ struct ssh_channel *b = (struct ssh_channel *) bv;
+ if (*a < b->localid)
+ return -1;
+ if (*a > b->localid)
+ return +1;
+ return 0;
+}
+
+static int ssh_rportcmp_ssh1(void *av, void *bv)
+{
+ struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
+ struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
+ int i;
+ if ( (i = strcmp(a->dhost, b->dhost)) != 0)
+ return i < 0 ? -1 : +1;
+ if (a->dport > b->dport)
+ return +1;
+ if (a->dport < b->dport)
+ return -1;
+ return 0;
+}
+
+static int ssh_rportcmp_ssh2(void *av, void *bv)
+{
+ struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
+ struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
+
+ if (a->sport > b->sport)
+ return +1;
+ if (a->sport < b->sport)
+ return -1;
+ return 0;
+}
+
+static int alloc_channel_id(void)
+{
+ const unsigned CHANNEL_NUMBER_OFFSET = 256;
+ unsigned low, high, mid;
+ int tsize;
+ struct ssh_channel *c;
+
+ /*
+ * First-fit allocation of channel numbers: always pick the
+ * lowest unused one. To do this, binary-search using the
+ * counted B-tree to find the largest channel ID which is in a
+ * contiguous sequence from the beginning. (Precisely
+ * everything in that sequence must have ID equal to its tree
+ * index plus CHANNEL_NUMBER_OFFSET.)
+ */
+ tsize = count234(ssh_channels);
+
+ low = -1;
+ high = tsize;
+ while (high - low > 1) {
+ mid = (high + low) / 2;
+ c = index234(ssh_channels, mid);
+ if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
+ low = mid; /* this one is fine */
+ else
+ high = mid; /* this one is past it */
+ }
+ /*
+ * Now low points to either -1, or the tree index of the
+ * largest ID in the initial sequence.
+ */
+ {
+ unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
+ assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
+ }
+ return low + 1 + CHANNEL_NUMBER_OFFSET;
+}
+
+static void c_write(char *buf, int len)
+{
+ if ((flags & FLAG_STDERR)) {
+ int i;
+ for (i = 0; i < len; i++)
+ if (buf[i] != '\r')
+ fputc(buf[i], stderr);
+ return;
+ }
+ from_backend(1, buf, len);
+}
+
+static void c_write_untrusted(char *buf, int len)
+{
+ int i;
+ for (i = 0; i < len; i++) {
+ if (buf[i] == '\n')
+ c_write("\r\n", 2);
+ else if ((buf[i] & 0x60) || (buf[i] == '\r'))
+ c_write(buf + i, 1);
+ }
+}
-static int (*s_rdpkt)(unsigned char **data, int *datalen);
+static void c_write_str(char *buf)
+{
+ c_write(buf, strlen(buf));
+}
/*
* Collect incoming data in the incoming packet buffer.
*/
static int ssh1_rdpkt(unsigned char **data, int *datalen)
{
- static long len, pad, biglen, to_read;
- static unsigned long realcrc, gotcrc;
- static unsigned char *p;
- static int i;
+ struct rdpkt1_state_tag *st = &rdpkt1_state;
crBegin;
-next_packet:
+ next_packet:
pktin.type = 0;
pktin.length = 0;
- for (i = len = 0; i < 4; i++) {
+ for (st->i = st->len = 0; st->i < 4; st->i++) {
while ((*datalen) == 0)
- crReturn(4-i);
- len = (len << 8) + **data;
+ crReturn(4 - st->i);
+ st->len = (st->len << 8) + **data;
(*data)++, (*datalen)--;
}
-#ifdef FWHACK
- if (len == 0x52656d6f) { /* "Remo"te server has closed ... */
- len = 0x300; /* big enough to carry to end */
- }
-#endif
-
- pad = 8 - (len % 8);
- biglen = len + pad;
- pktin.length = len - 5;
+ st->pad = 8 - (st->len % 8);
+ st->biglen = st->len + st->pad;
+ pktin.length = st->len - 5;
- if (pktin.maxlen < biglen) {
- pktin.maxlen = biglen;
- pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) :
- realloc(pktin.data, biglen+APIEXTRA));
+ if (pktin.maxlen < st->biglen) {
+ pktin.maxlen = st->biglen;
+ pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
+ srealloc(pktin.data, st->biglen + APIEXTRA));
if (!pktin.data)
fatalbox("Out of memory");
}
- to_read = biglen;
- p = pktin.data;
- while (to_read > 0) {
- static int chunk;
- chunk = to_read;
+ st->to_read = st->biglen;
+ st->p = pktin.data;
+ while (st->to_read > 0) {
+ st->chunk = st->to_read;
while ((*datalen) == 0)
- crReturn(to_read);
- if (chunk > (*datalen))
- chunk = (*datalen);
- memcpy(p, *data, chunk);
- *data += chunk;
- *datalen -= chunk;
- p += chunk;
- to_read -= chunk;
+ crReturn(st->to_read);
+ if (st->chunk > (*datalen))
+ st->chunk = (*datalen);
+ memcpy(st->p, *data, st->chunk);
+ *data += st->chunk;
+ *datalen -= st->chunk;
+ st->p += st->chunk;
+ st->to_read -= st->chunk;
+ }
+
+ if (cipher && detect_attack(pktin.data, st->biglen, NULL)) {
+ bombout(("Network attack (CRC compensation) detected!"));
+ crReturn(0);
}
if (cipher)
- cipher->decrypt(pktin.data, biglen);
+ cipher->decrypt(pktin.data, st->biglen);
+
+ st->realcrc = crc32(pktin.data, st->biglen - 4);
+ st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
+ if (st->gotcrc != st->realcrc) {
+ bombout(("Incorrect CRC received on packet"));
+ crReturn(0);
+ }
+
+ pktin.body = pktin.data + st->pad + 1;
- pktin.type = pktin.data[pad];
- pktin.body = pktin.data + pad + 1;
+ if (ssh1_compressing) {
+ unsigned char *decompblk;
+ int decomplen;
+ zlib_decompress_block(pktin.body - 1, pktin.length + 1,
+ &decompblk, &decomplen);
+
+ if (pktin.maxlen < st->pad + decomplen) {
+ pktin.maxlen = st->pad + decomplen;
+ pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
+ pktin.body = pktin.data + st->pad + 1;
+ if (!pktin.data)
+ fatalbox("Out of memory");
+ }
- realcrc = crc32(pktin.data, biglen-4);
- gotcrc = GET_32BIT(pktin.data+biglen-4);
- if (gotcrc != realcrc) {
- fatalbox("Incorrect CRC received on packet");
+ memcpy(pktin.body - 1, decompblk, decomplen);
+ sfree(decompblk);
+ pktin.length = decomplen - 1;
}
+ pktin.type = pktin.body[-1];
+
+ log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
+ pktin.body, pktin.length);
+
if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
- pktin.type == SSH1_SMSG_STDERR_DATA ||
- pktin.type == SSH1_MSG_DEBUG ||
- pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
- pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
- long strlen = GET_32BIT(pktin.body);
- if (strlen + 4 != pktin.length)
- fatalbox("Received data packet with bogus string length");
+ pktin.type == SSH1_SMSG_STDERR_DATA ||
+ pktin.type == SSH1_MSG_DEBUG ||
+ pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
+ pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
+ long stringlen = GET_32BIT(pktin.body);
+ if (stringlen + 4 != pktin.length) {
+ bombout(("Received data packet with bogus string length"));
+ crReturn(0);
+ }
}
if (pktin.type == SSH1_MSG_DEBUG) {
/* log debug message */
char buf[80];
- int strlen = GET_32BIT(pktin.body);
+ int stringlen = GET_32BIT(pktin.body);
strcpy(buf, "Remote: ");
- if (strlen > 70) strlen = 70;
- memcpy(buf+8, pktin.body+4, strlen);
- buf[8+strlen] = '\0';
+ if (stringlen > 70)
+ stringlen = 70;
+ memcpy(buf + 8, pktin.body + 4, stringlen);
+ buf[8 + stringlen] = '\0';
logevent(buf);
goto next_packet;
} else if (pktin.type == SSH1_MSG_IGNORE) {
goto next_packet;
}
+ if (pktin.type == SSH1_MSG_DISCONNECT) {
+ /* log reason code in disconnect message */
+ char buf[256];
+ unsigned msglen = GET_32BIT(pktin.body);
+ unsigned nowlen;
+ strcpy(buf, "Remote sent disconnect: ");
+ nowlen = strlen(buf);
+ if (msglen > sizeof(buf) - nowlen - 1)
+ msglen = sizeof(buf) - nowlen - 1;
+ memcpy(buf + nowlen, pktin.body + 4, msglen);
+ buf[nowlen + msglen] = '\0';
+ logevent(buf);
+ bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
+ crReturn(0);
+ }
+
crFinish(0);
}
static int ssh2_rdpkt(unsigned char **data, int *datalen)
{
- static long len, pad, payload, packetlen, maclen;
- static int i;
- static int cipherblk;
- static unsigned long incoming_sequence = 0;
+ struct rdpkt2_state_tag *st = &rdpkt2_state;
crBegin;
-next_packet:
-
+ next_packet:
pktin.type = 0;
pktin.length = 0;
-
- if (cipher)
- cipherblk = cipher->blksize;
+ if (sccipher)
+ st->cipherblk = sccipher->blksize;
else
- cipherblk = 8;
- if (cipherblk < 8)
- cipherblk = 8;
-
- if (pktin.maxlen < cipherblk) {
- pktin.maxlen = cipherblk;
- pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) :
- realloc(pktin.data, cipherblk+APIEXTRA));
+ st->cipherblk = 8;
+ if (st->cipherblk < 8)
+ st->cipherblk = 8;
+
+ if (pktin.maxlen < st->cipherblk) {
+ pktin.maxlen = st->cipherblk;
+ pktin.data =
+ (pktin.data ==
+ NULL ? smalloc(st->cipherblk +
+ APIEXTRA) : srealloc(pktin.data,
+ st->cipherblk +
+ APIEXTRA));
if (!pktin.data)
fatalbox("Out of memory");
}
* Acquire and decrypt the first block of the packet. This will
* contain the length and padding details.
*/
- for (i = len = 0; i < cipherblk; i++) {
+ for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
while ((*datalen) == 0)
- crReturn(cipherblk-i);
- pktin.data[i] = *(*data)++;
- (*datalen)--;
- }
-#ifdef FWHACK
- if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
- /* FIXME */
+ crReturn(st->cipherblk - st->i);
+ pktin.data[st->i] = *(*data)++;
+ (*datalen)--;
}
-#endif
+
if (sccipher)
- sccipher->decrypt(pktin.data, cipherblk);
+ sccipher->decrypt(pktin.data, st->cipherblk);
/*
* Now get the length and padding figures.
*/
- len = GET_32BIT(pktin.data);
- pad = pktin.data[4];
+ st->len = GET_32BIT(pktin.data);
+ st->pad = pktin.data[4];
/*
* This enables us to deduce the payload length.
*/
- payload = len - pad - 1;
+ st->payload = st->len - st->pad - 1;
- pktin.length = payload + 5;
+ pktin.length = st->payload + 5;
/*
* So now we can work out the total packet length.
*/
- packetlen = len + 4;
- maclen = scmac ? scmac->len : 0;
+ st->packetlen = st->len + 4;
+ st->maclen = scmac ? scmac->len : 0;
/*
* Adjust memory allocation if packet is too big.
*/
- if (pktin.maxlen < packetlen) {
- pktin.maxlen = packetlen;
- pktin.data = (pktin.data == NULL ? malloc(packetlen+APIEXTRA) :
- realloc(pktin.data, packetlen+APIEXTRA));
+ if (pktin.maxlen < st->packetlen + st->maclen) {
+ pktin.maxlen = st->packetlen + st->maclen;
+ pktin.data =
+ (pktin.data ==
+ NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
+ pktin.maxlen
+ +
+ APIEXTRA));
if (!pktin.data)
fatalbox("Out of memory");
}
/*
* Read and decrypt the remainder of the packet.
*/
- for (i = cipherblk; i < packetlen + maclen; i++) {
+ for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
+ st->i++) {
while ((*datalen) == 0)
- crReturn(packetlen + maclen - i);
- pktin.data[i] = *(*data)++;
- (*datalen)--;
+ crReturn(st->packetlen + st->maclen - st->i);
+ pktin.data[st->i] = *(*data)++;
+ (*datalen)--;
}
/* Decrypt everything _except_ the MAC. */
if (sccipher)
- sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk);
-
-#if 0
- debug(("Got packet len=%d pad=%d\r\n", len, pad));
- for (i = 0; i < packetlen; i++)
- debug((" %02x", (unsigned char)pktin.data[i]));
- debug(("\r\n"));
-#endif
+ sccipher->decrypt(pktin.data + st->cipherblk,
+ st->packetlen - st->cipherblk);
/*
* Check the MAC.
*/
- if (scmac && !scmac->verify(pktin.data, len+4, incoming_sequence))
- fatalbox("Incorrect MAC received on packet");
- incoming_sequence++; /* whether or not we MACed */
+ if (scmac
+ && !scmac->verify(pktin.data, st->len + 4,
+ st->incoming_sequence)) {
+ bombout(("Incorrect MAC received on packet"));
+ crReturn(0);
+ }
+ st->incoming_sequence++; /* whether or not we MACed */
+
+ /*
+ * Decompress packet payload.
+ */
+ {
+ unsigned char *newpayload;
+ int newlen;
+ if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
+ &newpayload, &newlen)) {
+ if (pktin.maxlen < newlen + 5) {
+ pktin.maxlen = newlen + 5;
+ pktin.data =
+ (pktin.data ==
+ NULL ? smalloc(pktin.maxlen +
+ APIEXTRA) : srealloc(pktin.data,
+ pktin.maxlen +
+ APIEXTRA));
+ if (!pktin.data)
+ fatalbox("Out of memory");
+ }
+ pktin.length = 5 + newlen;
+ memcpy(pktin.data + 5, newpayload, newlen);
+ sfree(newpayload);
+ }
+ }
pktin.savedpos = 6;
pktin.type = pktin.data[5];
- if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
- goto next_packet; /* FIXME: print DEBUG message */
-
- crFinish(0);
-}
+ log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
+ pktin.data+6, pktin.length-6);
-static void ssh_gotdata(unsigned char *data, int datalen)
-{
- while (datalen > 0) {
- if ( s_rdpkt(&data, &datalen) == 0 ) {
- ssh_protocol(NULL, 0, 1);
- if (ssh_state == SSH_STATE_CLOSED) {
- return;
+ switch (pktin.type) {
+ /*
+ * These packets we must handle instantly.
+ */
+ case SSH2_MSG_DISCONNECT:
+ {
+ /* log reason code in disconnect message */
+ char buf[256];
+ int reason = GET_32BIT(pktin.data + 6);
+ unsigned msglen = GET_32BIT(pktin.data + 10);
+ unsigned nowlen;
+ if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
+ sprintf(buf, "Received disconnect message (%s)",
+ ssh2_disconnect_reasons[reason]);
+ } else {
+ sprintf(buf, "Received disconnect message (unknown type %d)",
+ reason);
}
+ logevent(buf);
+ strcpy(buf, "Disconnection message text: ");
+ nowlen = strlen(buf);
+ if (msglen > sizeof(buf) - nowlen - 1)
+ msglen = sizeof(buf) - nowlen - 1;
+ memcpy(buf + nowlen, pktin.data + 14, msglen);
+ buf[nowlen + msglen] = '\0';
+ logevent(buf);
+ bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
+ reason,
+ (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
+ ssh2_disconnect_reasons[reason] : "unknown",
+ buf+nowlen));
+ crReturn(0);
}
+ break;
+ case SSH2_MSG_IGNORE:
+ goto next_packet;
+ case SSH2_MSG_DEBUG:
+ {
+ /* log the debug message */
+ char buf[512];
+ /* int display = pktin.body[6]; */
+ int stringlen = GET_32BIT(pktin.data+7);
+ int prefix;
+ strcpy(buf, "Remote debug message: ");
+ prefix = strlen(buf);
+ if (stringlen > sizeof(buf)-prefix-1)
+ stringlen = sizeof(buf)-prefix-1;
+ memcpy(buf + prefix, pktin.data + 11, stringlen);
+ buf[prefix + stringlen] = '\0';
+ logevent(buf);
+ }
+ goto next_packet; /* FIXME: print the debug message */
+
+ /*
+ * These packets we need do nothing about here.
+ */
+ case SSH2_MSG_UNIMPLEMENTED:
+ case SSH2_MSG_SERVICE_REQUEST:
+ case SSH2_MSG_SERVICE_ACCEPT:
+ case SSH2_MSG_KEXINIT:
+ case SSH2_MSG_NEWKEYS:
+ case SSH2_MSG_KEXDH_INIT:
+ case SSH2_MSG_KEXDH_REPLY:
+ /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
+ /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
+ case SSH2_MSG_KEX_DH_GEX_INIT:
+ case SSH2_MSG_KEX_DH_GEX_REPLY:
+ case SSH2_MSG_USERAUTH_REQUEST:
+ case SSH2_MSG_USERAUTH_FAILURE:
+ case SSH2_MSG_USERAUTH_SUCCESS:
+ case SSH2_MSG_USERAUTH_BANNER:
+ case SSH2_MSG_USERAUTH_PK_OK:
+ /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
+ /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
+ case SSH2_MSG_USERAUTH_INFO_RESPONSE:
+ case SSH2_MSG_GLOBAL_REQUEST:
+ case SSH2_MSG_REQUEST_SUCCESS:
+ case SSH2_MSG_REQUEST_FAILURE:
+ case SSH2_MSG_CHANNEL_OPEN:
+ case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
+ case SSH2_MSG_CHANNEL_OPEN_FAILURE:
+ case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
+ case SSH2_MSG_CHANNEL_DATA:
+ case SSH2_MSG_CHANNEL_EXTENDED_DATA:
+ case SSH2_MSG_CHANNEL_EOF:
+ case SSH2_MSG_CHANNEL_CLOSE:
+ case SSH2_MSG_CHANNEL_REQUEST:
+ case SSH2_MSG_CHANNEL_SUCCESS:
+ case SSH2_MSG_CHANNEL_FAILURE:
+ break;
+
+ /*
+ * For anything else we send SSH2_MSG_UNIMPLEMENTED.
+ */
+ default:
+ ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
+ ssh2_pkt_adduint32(st->incoming_sequence - 1);
+ ssh2_pkt_send();
+ break;
}
-}
+ crFinish(0);
+}
-static void s_wrpkt_start(int type, int len) {
+static void ssh1_pktout_size(int len)
+{
int pad, biglen;
len += 5; /* type and CRC */
- pad = 8 - (len%8);
+ pad = 8 - (len % 8);
biglen = len + pad;
- pktout.length = len-5;
+ pktout.length = len - 5;
if (pktout.maxlen < biglen) {
pktout.maxlen = biglen;
#ifdef MSCRYPTOAPI
/* Allocate enough buffer space for extra block
* for MS CryptEncrypt() */
- pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
- realloc(pktout.data, biglen+12));
+ pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
+ srealloc(pktout.data, biglen + 12));
#else
- pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
- realloc(pktout.data, biglen+4));
+ pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
+ srealloc(pktout.data, biglen + 4));
#endif
if (!pktout.data)
fatalbox("Out of memory");
}
+ pktout.body = pktout.data + 4 + pad + 1;
+}
+static void s_wrpkt_start(int type, int len)
+{
+ ssh1_pktout_size(len);
pktout.type = type;
- pktout.body = pktout.data+4+pad+1;
}
-static void s_wrpkt(void) {
+static int s_wrpkt_prepare(void)
+{
int pad, len, biglen, i;
unsigned long crc;
+ pktout.body[-1] = pktout.type;
+
+ log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
+ pktout.body, pktout.length);
+
+ if (ssh1_compressing) {
+ unsigned char *compblk;
+ int complen;
+ zlib_compress_block(pktout.body - 1, pktout.length + 1,
+ &compblk, &complen);
+ ssh1_pktout_size(complen - 1);
+ memcpy(pktout.body - 1, compblk, complen);
+ sfree(compblk);
+ }
+
len = pktout.length + 5; /* type and CRC */
- pad = 8 - (len%8);
+ pad = 8 - (len % 8);
biglen = len + pad;
- pktout.body[-1] = pktout.type;
- for (i=0; i<pad; i++)
- pktout.data[i+4] = random_byte();
- crc = crc32(pktout.data+4, biglen-4);
- PUT_32BIT(pktout.data+biglen, crc);
+ for (i = 0; i < pad; i++)
+ pktout.data[i + 4] = random_byte();
+ crc = crc32(pktout.data + 4, biglen - 4);
+ PUT_32BIT(pktout.data + biglen, crc);
PUT_32BIT(pktout.data, len);
if (cipher)
- cipher->encrypt(pktout.data+4, biglen);
+ cipher->encrypt(pktout.data + 4, biglen);
+
+ return biglen + 4;
+}
+
+static void s_wrpkt(void)
+{
+ int len, backlog;
+ len = s_wrpkt_prepare();
+ backlog = sk_write(s, pktout.data, len);
+ if (backlog > SSH_MAX_BACKLOG)
+ ssh_throttle_all(1, backlog);
+}
- s_write(pktout.data, biglen+4);
+static void s_wrpkt_defer(void)
+{
+ int len;
+ len = s_wrpkt_prepare();
+ if (deferred_len + len > deferred_size) {
+ deferred_size = deferred_len + len + 128;
+ deferred_send_data = srealloc(deferred_send_data, deferred_size);
+ }
+ memcpy(deferred_send_data + deferred_len, pktout.data, len);
+ deferred_len += len;
}
/*
- * Construct a packet with the specified contents and
- * send it to the server.
+ * Construct a packet with the specified contents.
*/
-static void send_packet(int pkttype, ...)
+static void construct_packet(int pkttype, va_list ap1, va_list ap2)
{
- va_list args;
unsigned char *p, *argp, argchar;
unsigned long argint;
int pktlen, argtype, arglen;
Bignum bn;
pktlen = 0;
- va_start(args, pkttype);
- while ((argtype = va_arg(args, int)) != PKT_END) {
+ while ((argtype = va_arg(ap1, int)) != PKT_END) {
switch (argtype) {
case PKT_INT:
- (void) va_arg(args, int);
+ (void) va_arg(ap1, int);
pktlen += 4;
break;
case PKT_CHAR:
- (void) va_arg(args, char);
+ (void) va_arg(ap1, char);
pktlen++;
break;
case PKT_DATA:
- (void) va_arg(args, unsigned char *);
- arglen = va_arg(args, int);
+ (void) va_arg(ap1, unsigned char *);
+ arglen = va_arg(ap1, int);
pktlen += arglen;
break;
case PKT_STR:
- argp = va_arg(args, unsigned char *);
+ argp = va_arg(ap1, unsigned char *);
arglen = strlen(argp);
pktlen += 4 + arglen;
break;
case PKT_BIGNUM:
- bn = va_arg(args, Bignum);
- pktlen += ssh1_bignum_length(bn);
+ bn = va_arg(ap1, Bignum);
+ pktlen += ssh1_bignum_length(bn);
break;
default:
assert(0);
}
}
- va_end(args);
s_wrpkt_start(pkttype, pktlen);
p = pktout.body;
- va_start(args, pkttype);
- while ((argtype = va_arg(args, int)) != PKT_END) {
+ while ((argtype = va_arg(ap2, int)) != PKT_END) {
switch (argtype) {
case PKT_INT:
- argint = va_arg(args, int);
+ argint = va_arg(ap2, int);
PUT_32BIT(p, argint);
p += 4;
break;
case PKT_CHAR:
- argchar = va_arg(args, unsigned char);
+ argchar = va_arg(ap2, unsigned char);
*p = argchar;
p++;
break;
case PKT_DATA:
- argp = va_arg(args, unsigned char *);
- arglen = va_arg(args, int);
+ argp = va_arg(ap2, unsigned char *);
+ arglen = va_arg(ap2, int);
memcpy(p, argp, arglen);
p += arglen;
break;
case PKT_STR:
- argp = va_arg(args, unsigned char *);
+ argp = va_arg(ap2, unsigned char *);
arglen = strlen(argp);
PUT_32BIT(p, arglen);
memcpy(p + 4, argp, arglen);
p += 4 + arglen;
break;
case PKT_BIGNUM:
- bn = va_arg(args, Bignum);
- p += ssh1_write_bignum(p, bn);
+ bn = va_arg(ap2, Bignum);
+ p += ssh1_write_bignum(p, bn);
break;
}
}
- va_end(args);
+}
+static void send_packet(int pkttype, ...)
+{
+ va_list ap1, ap2;
+ va_start(ap1, pkttype);
+ va_start(ap2, pkttype);
+ construct_packet(pkttype, ap1, ap2);
s_wrpkt();
}
+static void defer_packet(int pkttype, ...)
+{
+ va_list ap1, ap2;
+ va_start(ap1, pkttype);
+ va_start(ap2, pkttype);
+ construct_packet(pkttype, ap1, ap2);
+ s_wrpkt_defer();
+}
-/*
- * Connect to specified host and port.
- * Returns an error message, or NULL on success.
- * Also places the canonical host name into `realhost'.
- */
-static char *connect_to_host(char *host, int port, char **realhost)
+static int ssh_versioncmp(char *a, char *b)
{
- SOCKADDR_IN addr;
- struct hostent *h;
- unsigned long a;
-#ifdef FWHACK
- char *FWhost;
- int FWport;
-#endif
+ char *ae, *be;
+ unsigned long av, bv;
- savedhost = malloc(1+strlen(host));
- if (!savedhost)
- fatalbox("Out of memory");
- strcpy(savedhost, host);
+ av = strtoul(a, &ae, 10);
+ bv = strtoul(b, &be, 10);
+ if (av != bv)
+ return (av < bv ? -1 : +1);
+ if (*ae == '.')
+ ae++;
+ if (*be == '.')
+ be++;
+ av = strtoul(ae, &ae, 10);
+ bv = strtoul(be, &be, 10);
+ if (av != bv)
+ return (av < bv ? -1 : +1);
+ return 0;
+}
- if (port < 0)
- port = 22; /* default ssh port */
-#ifdef FWHACK
- FWhost = host;
- FWport = port;
- host = FWSTR;
- port = 23;
-#endif
+/*
+ * Utility routines for putting an SSH-protocol `string' and
+ * `uint32' into a SHA state.
+ */
+#include <stdio.h>
+static void sha_string(SHA_State * s, void *str, int len)
+{
+ unsigned char lenblk[4];
+ PUT_32BIT(lenblk, len);
+ SHA_Bytes(s, lenblk, 4);
+ SHA_Bytes(s, str, len);
+}
- /*
- * Try to find host.
- */
- if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
- if ( (h = gethostbyname(host)) == NULL)
- switch (WSAGetLastError()) {
- case WSAENETDOWN: return "Network is down";
- case WSAHOST_NOT_FOUND: case WSANO_DATA:
- return "Host does not exist";
- case WSATRY_AGAIN: return "Host not found";
- default: return "gethostbyname: unknown error";
- }
- memcpy (&a, h->h_addr, sizeof(a));
- *realhost = h->h_name;
- } else
- *realhost = host;
-#ifdef FWHACK
- *realhost = FWhost;
-#endif
- a = ntohl(a);
-
- /*
- * Open socket.
- */
- s = socket(AF_INET, SOCK_STREAM, 0);
- if (s == INVALID_SOCKET)
- switch (WSAGetLastError()) {
- case WSAENETDOWN: return "Network is down";
- case WSAEAFNOSUPPORT: return "TCP/IP support not present";
- default: return "socket(): unknown error";
- }
-
- /*
- * Bind to local address.
- */
- addr.sin_family = AF_INET;
- addr.sin_addr.s_addr = htonl(INADDR_ANY);
- addr.sin_port = htons(0);
- if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
- switch (WSAGetLastError()) {
- case WSAENETDOWN: return "Network is down";
- default: return "bind(): unknown error";
- }
-
- /*
- * Connect to remote address.
- */
- addr.sin_addr.s_addr = htonl(a);
- addr.sin_port = htons((short)port);
- if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
- switch (WSAGetLastError()) {
- case WSAENETDOWN: return "Network is down";
- case WSAECONNREFUSED: return "Connection refused";
- case WSAENETUNREACH: return "Network is unreachable";
- case WSAEHOSTUNREACH: return "No route to host";
- default: return "connect(): unknown error";
- }
-
-#ifdef FWHACK
- send(s, "connect ", 8, 0);
- send(s, FWhost, strlen(FWhost), 0);
- {
- char buf[20];
- sprintf(buf, " %d\n", FWport);
- send (s, buf, strlen(buf), 0);
- }
-#endif
-
- return NULL;
-}
-
-static int ssh_versioncmp(char *a, char *b) {
- char *ae, *be;
- unsigned long av, bv;
-
- av = strtoul(a, &ae, 10);
- bv = strtoul(b, &be, 10);
- if (av != bv) return (av < bv ? -1 : +1);
- if (*ae == '.') ae++;
- if (*be == '.') be++;
- av = strtoul(ae, &ae, 10);
- bv = strtoul(be, &be, 10);
- if (av != bv) return (av < bv ? -1 : +1);
- return 0;
-}
-
-
-/*
- * Utility routine for putting an SSH-protocol `string' into a SHA
- * state.
- */
-#include <stdio.h>
-void sha_string(SHA_State *s, void *str, int len) {
- unsigned char lenblk[4];
- PUT_32BIT(lenblk, len);
- SHA_Bytes(s, lenblk, 4);
- SHA_Bytes(s, str, len);
+static void sha_uint32(SHA_State * s, unsigned i)
+{
+ unsigned char intblk[4];
+ PUT_32BIT(intblk, i);
+ SHA_Bytes(s, intblk, 4);
}
/*
* SSH2 packet construction functions.
*/
-void ssh2_pkt_adddata(void *data, int len) {
- pktout.length += len;
- if (pktout.maxlen < pktout.length) {
- pktout.maxlen = pktout.length + 256;
- pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
- realloc(pktout.data, pktout.maxlen+APIEXTRA));
- if (!pktout.data)
- fatalbox("Out of memory");
+static void ssh2_pkt_ensure(int length)
+{
+ if (pktout.maxlen < length) {
+ pktout.maxlen = length + 256;
+ pktout.data =
+ (pktout.data ==
+ NULL ? smalloc(pktout.maxlen +
+ APIEXTRA) : srealloc(pktout.data,
+ pktout.maxlen +
+ APIEXTRA));
+ if (!pktout.data)
+ fatalbox("Out of memory");
}
- memcpy(pktout.data+pktout.length-len, data, len);
}
-void ssh2_pkt_addbyte(unsigned char byte) {
+static void ssh2_pkt_adddata(void *data, int len)
+{
+ pktout.length += len;
+ ssh2_pkt_ensure(pktout.length);
+ memcpy(pktout.data + pktout.length - len, data, len);
+}
+static void ssh2_pkt_addbyte(unsigned char byte)
+{
ssh2_pkt_adddata(&byte, 1);
}
-void ssh2_pkt_init(int pkt_type) {
+static void ssh2_pkt_init(int pkt_type)
+{
pktout.length = 5;
- ssh2_pkt_addbyte((unsigned char)pkt_type);
+ ssh2_pkt_addbyte((unsigned char) pkt_type);
}
-void ssh2_pkt_addbool(unsigned char value) {
+static void ssh2_pkt_addbool(unsigned char value)
+{
ssh2_pkt_adddata(&value, 1);
}
-void ssh2_pkt_adduint32(unsigned long value) {
+static void ssh2_pkt_adduint32(unsigned long value)
+{
unsigned char x[4];
PUT_32BIT(x, value);
ssh2_pkt_adddata(x, 4);
}
-void ssh2_pkt_addstring_start(void) {
+static void ssh2_pkt_addstring_start(void)
+{
ssh2_pkt_adduint32(0);
pktout.savedpos = pktout.length;
}
-void ssh2_pkt_addstring_str(char *data) {
+static void ssh2_pkt_addstring_str(char *data)
+{
ssh2_pkt_adddata(data, strlen(data));
PUT_32BIT(pktout.data + pktout.savedpos - 4,
- pktout.length - pktout.savedpos);
+ pktout.length - pktout.savedpos);
}
-void ssh2_pkt_addstring_data(char *data, int len) {
+static void ssh2_pkt_addstring_data(char *data, int len)
+{
ssh2_pkt_adddata(data, len);
PUT_32BIT(pktout.data + pktout.savedpos - 4,
- pktout.length - pktout.savedpos);
+ pktout.length - pktout.savedpos);
}
-void ssh2_pkt_addstring(char *data) {
+static void ssh2_pkt_addstring(char *data)
+{
ssh2_pkt_addstring_start();
ssh2_pkt_addstring_str(data);
}
-char *ssh2_mpint_fmt(Bignum b, int *len) {
+static char *ssh2_mpint_fmt(Bignum b, int *len)
+{
unsigned char *p;
- int i, n = b[0];
- p = malloc(n * 2 + 1);
+ int i, n = (bignum_bitcount(b) + 7) / 8;
+ p = smalloc(n + 1);
if (!p)
- fatalbox("out of memory");
+ fatalbox("out of memory");
p[0] = 0;
- for (i = 0; i < n; i++) {
- p[i*2+1] = (b[n-i] >> 8) & 0xFF;
- p[i*2+2] = (b[n-i] ) & 0xFF;
- }
+ for (i = 1; i <= n; i++)
+ p[i] = bignum_byte(b, n - i);
i = 0;
- while (p[i] == 0 && (p[i+1] & 0x80) == 0)
- i++;
- memmove(p, p+i, n*2+1-i);
- *len = n*2+1-i;
+ while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
+ i++;
+ memmove(p, p + i, n + 1 - i);
+ *len = n + 1 - i;
return p;
}
-void ssh2_pkt_addmp(Bignum b) {
+static void ssh2_pkt_addmp(Bignum b)
+{
unsigned char *p;
int len;
p = ssh2_mpint_fmt(b, &len);
ssh2_pkt_addstring_start();
ssh2_pkt_addstring_data(p, len);
- free(p);
+ sfree(p);
}
-void ssh2_pkt_send(void) {
+
+/*
+ * Construct an SSH2 final-form packet: compress it, encrypt it,
+ * put the MAC on it. Final packet, ready to be sent, is stored in
+ * pktout.data. Total length is returned.
+ */
+static int ssh2_pkt_construct(void)
+{
int cipherblk, maclen, padding, i;
static unsigned long outgoing_sequence = 0;
+ log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
+ pktout.data + 6, pktout.length - 6);
+
+ /*
+ * Compress packet payload.
+ */
+ {
+ unsigned char *newpayload;
+ int newlen;
+ if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
+ &newpayload, &newlen)) {
+ pktout.length = 5;
+ ssh2_pkt_adddata(newpayload, newlen);
+ sfree(newpayload);
+ }
+ }
+
/*
* Add padding. At least four bytes, and must also bring total
* length (minus MAC) up to a multiple of the block size.
*/
- cipherblk = cipher ? cipher->blksize : 8; /* block size */
- cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
+ cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
+ cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
padding = 4;
- padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
+ padding +=
+ (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
+ maclen = csmac ? csmac->len : 0;
+ ssh2_pkt_ensure(pktout.length + padding + maclen);
pktout.data[4] = padding;
for (i = 0; i < padding; i++)
- pktout.data[pktout.length + i] = random_byte();
+ pktout.data[pktout.length + i] = random_byte();
PUT_32BIT(pktout.data, pktout.length + padding - 4);
if (csmac)
- csmac->generate(pktout.data, pktout.length + padding,
- outgoing_sequence);
- outgoing_sequence++; /* whether or not we MACed */
-
-#if 0
- debug(("Sending packet len=%d\r\n", pktout.length+padding));
- for (i = 0; i < pktout.length+padding; i++)
- debug((" %02x", (unsigned char)pktout.data[i]));
- debug(("\r\n"));
-#endif
+ csmac->generate(pktout.data, pktout.length + padding,
+ outgoing_sequence);
+ outgoing_sequence++; /* whether or not we MACed */
if (cscipher)
- cscipher->encrypt(pktout.data, pktout.length + padding);
- maclen = csmac ? csmac->len : 0;
+ cscipher->encrypt(pktout.data, pktout.length + padding);
+
+ /* Ready-to-send packet starts at pktout.data. We return length. */
+ return pktout.length + padding + maclen;
+}
+
+/*
+ * Construct and send an SSH2 packet immediately.
+ */
+static void ssh2_pkt_send(void)
+{
+ int len;
+ int backlog;
+ len = ssh2_pkt_construct();
+ backlog = sk_write(s, pktout.data, len);
+ if (backlog > SSH_MAX_BACKLOG)
+ ssh_throttle_all(1, backlog);
+}
+
+/*
+ * Construct an SSH2 packet and add it to a deferred data block.
+ * Useful for sending multiple packets in a single sk_write() call,
+ * to prevent a traffic-analysing listener from being able to work
+ * out the length of any particular packet (such as the password
+ * packet).
+ *
+ * Note that because SSH2 sequence-numbers its packets, this can
+ * NOT be used as an m4-style `defer' allowing packets to be
+ * constructed in one order and sent in another.
+ */
+static void ssh2_pkt_defer(void)
+{
+ int len = ssh2_pkt_construct();
+ if (deferred_len + len > deferred_size) {
+ deferred_size = deferred_len + len + 128;
+ deferred_send_data = srealloc(deferred_send_data, deferred_size);
+ }
+ memcpy(deferred_send_data + deferred_len, pktout.data, len);
+ deferred_len += len;
+}
- s_write(pktout.data, pktout.length + padding + maclen);
+/*
+ * Send the whole deferred data block constructed by
+ * ssh2_pkt_defer() or SSH1's defer_packet().
+ */
+static void ssh_pkt_defersend(void)
+{
+ int backlog;
+ backlog = sk_write(s, deferred_send_data, deferred_len);
+ deferred_len = deferred_size = 0;
+ sfree(deferred_send_data);
+ deferred_send_data = NULL;
+ if (backlog > SSH_MAX_BACKLOG)
+ ssh_throttle_all(1, backlog);
}
#if 0
-void bndebug(char *string, Bignum b) {
+void bndebug(char *string, Bignum b)
+{
unsigned char *p;
int i, len;
p = ssh2_mpint_fmt(b, &len);
debug(("%s", string));
for (i = 0; i < len; i++)
- debug((" %02x", p[i]));
- debug(("\r\n"));
- free(p);
+ debug((" %02x", p[i]));
+ debug(("\n"));
+ sfree(p);
}
#endif
-void sha_mpint(SHA_State *s, Bignum b) {
+static void sha_mpint(SHA_State * s, Bignum b)
+{
unsigned char *p;
int len;
p = ssh2_mpint_fmt(b, &len);
sha_string(s, p, len);
- free(p);
+ sfree(p);
}
/*
* SSH2 packet decode functions.
*/
-unsigned long ssh2_pkt_getuint32(void) {
+static unsigned long ssh2_pkt_getuint32(void)
+{
unsigned long value;
if (pktin.length - pktin.savedpos < 4)
- return 0; /* arrgh, no way to decline (FIXME?) */
- value = GET_32BIT(pktin.data+pktin.savedpos);
+ return 0; /* arrgh, no way to decline (FIXME?) */
+ value = GET_32BIT(pktin.data + pktin.savedpos);
pktin.savedpos += 4;
return value;
}
-void ssh2_pkt_getstring(char **p, int *length) {
+static int ssh2_pkt_getbool(void)
+{
+ unsigned long value;
+ if (pktin.length - pktin.savedpos < 1)
+ return 0; /* arrgh, no way to decline (FIXME?) */
+ value = pktin.data[pktin.savedpos] != 0;
+ pktin.savedpos++;
+ return value;
+}
+static void ssh2_pkt_getstring(char **p, int *length)
+{
*p = NULL;
if (pktin.length - pktin.savedpos < 4)
- return;
- *length = GET_32BIT(pktin.data+pktin.savedpos);
+ return;
+ *length = GET_32BIT(pktin.data + pktin.savedpos);
pktin.savedpos += 4;
if (pktin.length - pktin.savedpos < *length)
- return;
- *p = pktin.data+pktin.savedpos;
+ return;
+ *p = pktin.data + pktin.savedpos;
pktin.savedpos += *length;
}
-Bignum ssh2_pkt_getmp(void) {
+static Bignum ssh2_pkt_getmp(void)
+{
char *p;
- int i, j, length;
+ int length;
Bignum b;
ssh2_pkt_getstring(&p, &length);
if (!p)
- return NULL;
- if (p[0] & 0x80)
- fatalbox("internal error: Can't handle negative mpints");
- b = newbn((length+1)/2);
- for (i = 0; i < length; i++) {
- j = length - 1 - i;
- if (j & 1)
- b[j/2+1] |= ((unsigned char)p[i]) << 8;
- else
- b[j/2+1] |= ((unsigned char)p[i]);
+ return NULL;
+ if (p[0] & 0x80) {
+ bombout(("internal error: Can't handle negative mpints"));
+ return NULL;
}
+ b = bignum_from_bytes(p, length);
return b;
}
-static int do_ssh_init(void) {
- char c, *vsp;
- char version[10];
- char vstring[80];
- char vlog[sizeof(vstring)+20];
- int i;
+/*
+ * Examine the remote side's version string and compare it against
+ * a list of known buggy implementations.
+ */
+static void ssh_detect_bugs(char *vstring)
+{
+ char *imp; /* pointer to implementation part */
+ imp = vstring;
+ imp += strcspn(imp, "-");
+ if (*imp) imp++;
+ imp += strcspn(imp, "-");
+ if (*imp) imp++;
+
+ ssh_remote_bugs = 0;
+
+ if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
+ !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
+ !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
+ /*
+ * These versions don't support SSH1_MSG_IGNORE, so we have
+ * to use a different defence against password length
+ * sniffing.
+ */
+ ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
+ logevent("We believe remote version has SSH1 ignore bug");
+ }
-#ifdef FWHACK
+ if (!strcmp(imp, "Cisco-1.25")) {
+ /*
+ * These versions need a plain password sent; they can't
+ * handle having a null and a random length of data after
+ * the password.
+ */
+ ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
+ logevent("We believe remote version needs a plain SSH1 password");
+ }
+
+ if (!strcmp(imp, "Cisco-1.25")) {
+ /*
+ * These versions apparently have no clue whatever about
+ * RSA authentication and will panic and die if they see
+ * an AUTH_RSA message.
+ */
+ ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
+ logevent("We believe remote version can't handle RSA authentication");
+ }
+
+ if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
+ !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
+ !strncmp(imp, "2.1 ", 4)) {
+ /*
+ * These versions have the HMAC bug.
+ */
+ ssh_remote_bugs |= BUG_SSH2_HMAC;
+ logevent("We believe remote version has SSH2 HMAC bug");
+ }
+}
+
+static int do_ssh_init(unsigned char c)
+{
+ static int vslen;
+ static char version[10];
+ static char *vstring;
+ static int vstrsize;
+ static char *vlog;
+ static int i;
+
+ crBegin;
+
+ /* Search for the string "SSH-" in the input. */
i = 0;
- while (s_read(&c, 1) == 1) {
- if (c == 'S' && i < 2) i++;
- else if (c == 'S' && i == 2) i = 2;
- else if (c == 'H' && i == 2) break;
- else i = 0;
+ while (1) {
+ static const int transS[] = { 1, 2, 2, 1 };
+ static const int transH[] = { 0, 0, 3, 0 };
+ static const int transminus[] = { 0, 0, 0, -1 };
+ if (c == 'S')
+ i = transS[i];
+ else if (c == 'H')
+ i = transH[i];
+ else if (c == '-')
+ i = transminus[i];
+ else
+ i = 0;
+ if (i < 0)
+ break;
+ crReturn(1); /* get another character */
}
-#else
- if (s_read(&c,1) != 1 || c != 'S') return 0;
- if (s_read(&c,1) != 1 || c != 'S') return 0;
- if (s_read(&c,1) != 1 || c != 'H') return 0;
-#endif
+
+ vstrsize = 16;
+ vstring = smalloc(vstrsize);
strcpy(vstring, "SSH-");
- vsp = vstring+4;
- if (s_read(&c,1) != 1 || c != '-') return 0;
+ vslen = 4;
i = 0;
while (1) {
- if (s_read(&c,1) != 1)
- return 0;
- if (vsp < vstring+sizeof(vstring)-1)
- *vsp++ = c;
+ crReturn(1); /* get another char */
+ if (vslen >= vstrsize - 1) {
+ vstrsize += 16;
+ vstring = srealloc(vstring, vstrsize);
+ }
+ vstring[vslen++] = c;
if (i >= 0) {
if (c == '-') {
version[i] = '\0';
i = -1;
- } else if (i < sizeof(version)-1)
+ } else if (i < sizeof(version) - 1)
version[i++] = c;
- }
- else if (c == '\n')
+ } else if (c == '\n')
break;
}
- *vsp = 0;
+ ssh_agentfwd_enabled = FALSE;
+ rdpkt2_state.incoming_sequence = 0;
+
+ vstring[vslen] = 0;
+ vlog = smalloc(20 + vslen);
+ vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
sprintf(vlog, "Server version: %s", vstring);
- vlog[strcspn(vlog, "\r\n")] = '\0';
logevent(vlog);
+ ssh_detect_bugs(vstring);
+ sfree(vlog);
/*
* Server version "1.99" means we can choose whether we use v1
* or v2 protocol. Choice is based on cfg.sshprot.
*/
if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
- /*
- * This is a v2 server. Begin v2 protocol.
- */
- char *verstring = "SSH-2.0-PuTTY";
- SHA_Init(&exhash);
- /*
- * Hash our version string and their version string.
- */
- sha_string(&exhash, verstring, strlen(verstring));
- sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
- sprintf(vstring, "%s\n", verstring);
- sprintf(vlog, "We claim version: %s", verstring);
- logevent(vlog);
- logevent("Using SSH protocol version 2");
- s_write(vstring, strlen(vstring));
- ssh_protocol = ssh2_protocol;
- ssh_version = 2;
- s_rdpkt = ssh2_rdpkt;
+ /*
+ * This is a v2 server. Begin v2 protocol.
+ */
+ char verstring[80], vlog[100];
+ sprintf(verstring, "SSH-2.0-%s", sshver);
+ SHA_Init(&exhashbase);
+ /*
+ * Hash our version string and their version string.
+ */
+ sha_string(&exhashbase, verstring, strlen(verstring));
+ sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
+ sprintf(vlog, "We claim version: %s", verstring);
+ logevent(vlog);
+ strcat(verstring, "\n");
+ logevent("Using SSH protocol version 2");
+ sk_write(s, verstring, strlen(verstring));
+ ssh_protocol = ssh2_protocol;
+ ssh_version = 2;
+ s_rdpkt = ssh2_rdpkt;
} else {
- /*
- * This is a v1 server. Begin v1 protocol.
- */
- sprintf(vstring, "SSH-%s-PuTTY\n",
- (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
- sprintf(vlog, "We claim version: %s", vstring);
- vlog[strcspn(vlog, "\r\n")] = '\0';
- logevent(vlog);
- logevent("Using SSH protocol version 1");
- s_write(vstring, strlen(vstring));
- ssh_protocol = ssh1_protocol;
- ssh_version = 1;
- s_rdpkt = ssh1_rdpkt;
+ /*
+ * This is a v1 server. Begin v1 protocol.
+ */
+ char verstring[80], vlog[100];
+ sprintf(verstring, "SSH-%s-%s",
+ (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
+ sshver);
+ sprintf(vlog, "We claim version: %s", verstring);
+ logevent(vlog);
+ strcat(verstring, "\n");
+ logevent("Using SSH protocol version 1");
+ sk_write(s, verstring, strlen(verstring));
+ ssh_protocol = ssh1_protocol;
+ ssh_version = 1;
+ s_rdpkt = ssh1_rdpkt;
}
- ssh_send_ok = 0;
- return 1;
+ ssh_state = SSH_STATE_BEFORE_SIZE;
+
+ sfree(vstring);
+
+ crFinish(0);
}
-/*
- * Handle the key exchange and user authentication phases.
- */
-static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
+static void ssh_gotdata(unsigned char *data, int datalen)
{
- int i, j, len;
- unsigned char *rsabuf, *keystr1, *keystr2;
- unsigned char cookie[8];
- struct RSAKey servkey, hostkey;
- struct MD5Context md5c;
- static unsigned long supported_ciphers_mask, supported_auths_mask;
- static int tried_publickey;
- static unsigned char session_id[16];
- int cipher_type;
-
crBegin;
- if (!ispkt) crWaitUntil(ispkt);
-
- if (pktin.type != SSH1_SMSG_PUBLIC_KEY)
- fatalbox("Public key packet not received");
-
- logevent("Received public keys");
-
- memcpy(cookie, pktin.body, 8);
-
- i = makekey(pktin.body+8, &servkey, &keystr1, 0);
- j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
-
/*
- * Hash the host key and print the hash in the log box. Just as
- * a last resort in case the registry's host key checking is
- * compromised, we'll allow the user some ability to verify
- * host keys by eye.
+ * To begin with, feed the characters one by one to the
+ * protocol initialisation / selection function do_ssh_init().
+ * When that returns 0, we're done with the initial greeting
+ * exchange and can move on to packet discipline.
*/
- MD5Init(&md5c);
- MD5Update(&md5c, keystr2, hostkey.bytes);
- MD5Final(session_id, &md5c);
- {
- char logmsg[80];
- int i;
- logevent("Host key MD5 is:");
- strcpy(logmsg, " ");
- for (i = 0; i < 16; i++)
- sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]);
- logevent(logmsg);
+ while (1) {
+ int ret;
+ if (datalen == 0)
+ crReturnV; /* more data please */
+ ret = do_ssh_init(*data);
+ data++;
+ datalen--;
+ if (ret == 0)
+ break;
}
- supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
- supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
-
- MD5Init(&md5c);
- MD5Update(&md5c, keystr2, hostkey.bytes);
- MD5Update(&md5c, keystr1, servkey.bytes);
- MD5Update(&md5c, pktin.body, 8);
- MD5Final(session_id, &md5c);
-
- for (i=0; i<32; i++)
- session_key[i] = random_byte();
-
- len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
-
- rsabuf = malloc(len);
- if (!rsabuf)
- fatalbox("Out of memory");
-
/*
- * Verify the host key.
+ * We emerge from that loop when the initial negotiation is
+ * over and we have selected an s_rdpkt function. Now pass
+ * everything to s_rdpkt, and then pass the resulting packets
+ * to the proper protocol handler.
*/
- {
- /*
- * First format the key into a string.
- */
- int len = rsastr_len(&hostkey);
- char *keystr = malloc(len);
- if (!keystr)
- fatalbox("Out of memory");
- rsastr_fmt(keystr, &hostkey);
- verify_ssh_host_key(savedhost, keystr);
- free(keystr);
+ if (datalen == 0)
+ crReturnV;
+ while (1) {
+ while (datalen > 0) {
+ if (s_rdpkt(&data, &datalen) == 0) {
+ if (ssh_state == SSH_STATE_CLOSED) {
+ return;
+ }
+ ssh_protocol(NULL, 0, 1);
+ if (ssh_state == SSH_STATE_CLOSED) {
+ return;
+ }
+ }
+ }
+ crReturnV;
}
+ crFinishV;
+}
- for (i=0; i<32; i++) {
- rsabuf[i] = session_key[i];
- if (i < 16)
- rsabuf[i] ^= session_id[i];
+static int ssh_closing(Plug plug, char *error_msg, int error_code,
+ int calling_back)
+{
+ ssh_state = SSH_STATE_CLOSED;
+ if (s) {
+ sk_close(s);
+ s = NULL;
}
-
- if (hostkey.bytes > servkey.bytes) {
- rsaencrypt(rsabuf, 32, &servkey);
- rsaencrypt(rsabuf, servkey.bytes, &hostkey);
+ if (error_msg) {
+ /* A socket error has occurred. */
+ connection_fatal(error_msg);
} else {
- rsaencrypt(rsabuf, 32, &hostkey);
- rsaencrypt(rsabuf, hostkey.bytes, &servkey);
+ /* Otherwise, the remote side closed the connection normally. */
}
+ return 0;
+}
- logevent("Encrypted session key");
-
- cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
- cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
- SSH_CIPHER_3DES;
- if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
- c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
- cipher_type = SSH_CIPHER_3DES;
- }
- switch (cipher_type) {
- case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
- case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
- case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
+static int ssh_receive(Plug plug, int urgent, char *data, int len)
+{
+ ssh_gotdata(data, len);
+ if (ssh_state == SSH_STATE_CLOSED) {
+ if (s) {
+ sk_close(s);
+ s = NULL;
+ }
+ return 0;
}
+ return 1;
+}
- send_packet(SSH1_CMSG_SESSION_KEY,
- PKT_CHAR, cipher_type,
- PKT_DATA, cookie, 8,
- PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
- PKT_DATA, rsabuf, len,
- PKT_INT, 0,
- PKT_END);
-
- logevent("Trying to enable encryption...");
+static void ssh_sent(Plug plug, int bufsize)
+{
+ /*
+ * If the send backlog on the SSH socket itself clears, we
+ * should unthrottle the whole world if it was throttled.
+ */
+ if (bufsize < SSH_MAX_BACKLOG)
+ ssh_throttle_all(0, bufsize);
+}
- free(rsabuf);
+/*
+ * Connect to specified host and port.
+ * Returns an error message, or NULL on success.
+ * Also places the canonical host name into `realhost'. It must be
+ * freed by the caller.
+ */
+static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
+{
+ static struct plug_function_table fn_table = {
+ ssh_closing,
+ ssh_receive,
+ ssh_sent,
+ NULL
+ }, *fn_table_ptr = &fn_table;
+
+ SockAddr addr;
+ char *err;
+#ifdef FWHACK
+ char *FWhost;
+ int FWport;
+#endif
- cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish :
- cipher_type == SSH_CIPHER_DES ? &ssh_des :
- &ssh_3des;
- cipher->sesskey(session_key);
+ savedhost = smalloc(1 + strlen(host));
+ if (!savedhost)
+ fatalbox("Out of memory");
+ strcpy(savedhost, host);
- crWaitUntil(ispkt);
+ if (port < 0)
+ port = 22; /* default ssh port */
+ savedport = port;
- if (pktin.type != SSH1_SMSG_SUCCESS)
- fatalbox("Encryption not successfully enabled");
+#ifdef FWHACK
+ FWhost = host;
+ FWport = port;
+ host = FWSTR;
+ port = 23;
+#endif
- logevent("Successfully started encryption");
+ /*
+ * Try to find host.
+ */
+ {
+ char buf[200];
+ sprintf(buf, "Looking up host \"%.170s\"", host);
+ logevent(buf);
+ }
+ addr = sk_namelookup(host, realhost);
+ if ((err = sk_addr_error(addr)))
+ return err;
+
+#ifdef FWHACK
+ *realhost = strdup(FWhost);
+#endif
+
+ /*
+ * Open socket.
+ */
+ {
+ char buf[200], addrbuf[100];
+ sk_getaddr(addr, addrbuf, 100);
+ sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
+ logevent(buf);
+ }
+ s = sk_new(addr, port, 0, 1, nodelay, &fn_table_ptr);
+ if ((err = sk_socket_error(s))) {
+ s = NULL;
+ return err;
+ }
+
+#ifdef FWHACK
+ sk_write(s, "connect ", 8);
+ sk_write(s, FWhost, strlen(FWhost));
+ {
+ char buf[20];
+ sprintf(buf, " %d\n", FWport);
+ sk_write(s, buf, strlen(buf));
+ }
+#endif
+
+ return NULL;
+}
+
+/*
+ * Throttle or unthrottle the SSH connection.
+ */
+static void ssh1_throttle(int adjust)
+{
+ int old_count = ssh1_throttle_count;
+ ssh1_throttle_count += adjust;
+ assert(ssh1_throttle_count >= 0);
+ if (ssh1_throttle_count && !old_count) {
+ sk_set_frozen(s, 1);
+ } else if (!ssh1_throttle_count && old_count) {
+ sk_set_frozen(s, 0);
+ }
+}
+
+/*
+ * Throttle or unthrottle _all_ local data streams (for when sends
+ * on the SSH connection itself back up).
+ */
+static void ssh_throttle_all(int enable, int bufsize)
+{
+ int i;
+ struct ssh_channel *c;
+
+ if (enable == ssh_throttled_all)
+ return;
+ ssh_throttled_all = enable;
+ ssh_overall_bufsize = bufsize;
+ if (!ssh_channels)
+ return;
+ for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
+ switch (c->type) {
+ case CHAN_MAINSESSION:
+ /*
+ * This is treated separately, outside the switch.
+ */
+ break;
+ case CHAN_X11:
+ x11_override_throttle(c->u.x11.s, enable);
+ break;
+ case CHAN_AGENT:
+ /* Agent channels require no buffer management. */
+ break;
+ case CHAN_SOCKDATA:
+ pfd_override_throttle(c->u.x11.s, enable);
+ break;
+ }
+ }
+}
+
+/*
+ * Handle the key exchange and user authentication phases.
+ */
+static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
+{
+ int i, j;
+ static int len;
+ static unsigned char *rsabuf, *keystr1, *keystr2;
+ unsigned char cookie[8];
+ struct RSAKey servkey, hostkey;
+ struct MD5Context md5c;
+ static unsigned long supported_ciphers_mask, supported_auths_mask;
+ static int tried_publickey, tried_agent;
+ static int tis_auth_refused, ccard_auth_refused;
+ static unsigned char session_id[16];
+ static int cipher_type;
+ static char username[100];
+ static void *publickey_blob;
+ int publickey_bloblen;
+
+ crBegin;
+
+ if (!ispkt)
+ crWaitUntil(ispkt);
+
+ if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
+ bombout(("Public key packet not received"));
+ crReturn(0);
+ }
+
+ logevent("Received public keys");
+
+ memcpy(cookie, pktin.body, 8);
+
+ i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
+ j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
+
+ /*
+ * Log the host key fingerprint.
+ */
+ {
+ char logmsg[80];
+ logevent("Host key fingerprint is:");
+ strcpy(logmsg, " ");
+ hostkey.comment = NULL;
+ rsa_fingerprint(logmsg + strlen(logmsg),
+ sizeof(logmsg) - strlen(logmsg), &hostkey);
+ logevent(logmsg);
+ }
+
+ ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
+ supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
+ supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
+
+ ssh1_local_protoflags =
+ ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
+ ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
+
+ MD5Init(&md5c);
+ MD5Update(&md5c, keystr2, hostkey.bytes);
+ MD5Update(&md5c, keystr1, servkey.bytes);
+ MD5Update(&md5c, pktin.body, 8);
+ MD5Final(session_id, &md5c);
+
+ for (i = 0; i < 32; i++)
+ session_key[i] = random_byte();
+
+ len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
+
+ rsabuf = smalloc(len);
+ if (!rsabuf)
+ fatalbox("Out of memory");
+
+ /*
+ * Verify the host key.
+ */
+ {
+ /*
+ * First format the key into a string.
+ */
+ int len = rsastr_len(&hostkey);
+ char fingerprint[100];
+ char *keystr = smalloc(len);
+ if (!keystr)
+ fatalbox("Out of memory");
+ rsastr_fmt(keystr, &hostkey);
+ rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
+ verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
+ fingerprint);
+ sfree(keystr);
+ }
+
+ for (i = 0; i < 32; i++) {
+ rsabuf[i] = session_key[i];
+ if (i < 16)
+ rsabuf[i] ^= session_id[i];
+ }
+
+ if (hostkey.bytes > servkey.bytes) {
+ rsaencrypt(rsabuf, 32, &servkey);
+ rsaencrypt(rsabuf, servkey.bytes, &hostkey);
+ } else {
+ rsaencrypt(rsabuf, 32, &hostkey);
+ rsaencrypt(rsabuf, hostkey.bytes, &servkey);
+ }
+
+ logevent("Encrypted session key");
+
+ {
+ int cipher_chosen = 0, warn = 0;
+ char *cipher_string = NULL;
+ for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
+ int next_cipher = cfg.ssh_cipherlist[i];
+ if (next_cipher == CIPHER_WARN) {
+ /* If/when we choose a cipher, warn about it */
+ warn = 1;
+ } else if (next_cipher == CIPHER_AES) {
+ /* XXX Probably don't need to mention this. */
+ logevent("AES not supported in SSH1, skipping");
+ } else {
+ switch (next_cipher) {
+ case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
+ cipher_string = "3DES"; break;
+ case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
+ cipher_string = "Blowfish"; break;
+ case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
+ cipher_string = "single-DES"; break;
+ }
+ if (supported_ciphers_mask & (1 << cipher_type))
+ cipher_chosen = 1;
+ }
+ }
+ if (!cipher_chosen) {
+ if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
+ bombout(("Server violates SSH 1 protocol by not "
+ "supporting 3DES encryption"));
+ else
+ /* shouldn't happen */
+ bombout(("No supported ciphers found"));
+ crReturn(0);
+ }
+
+ /* Warn about chosen cipher if necessary. */
+ if (warn)
+ askcipher(cipher_string, 0);
+ }
+
+ switch (cipher_type) {
+ case SSH_CIPHER_3DES:
+ logevent("Using 3DES encryption");
+ break;
+ case SSH_CIPHER_DES:
+ logevent("Using single-DES encryption");
+ break;
+ case SSH_CIPHER_BLOWFISH:
+ logevent("Using Blowfish encryption");
+ break;
+ }
+
+ send_packet(SSH1_CMSG_SESSION_KEY,
+ PKT_CHAR, cipher_type,
+ PKT_DATA, cookie, 8,
+ PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
+ PKT_DATA, rsabuf, len,
+ PKT_INT, ssh1_local_protoflags, PKT_END);
+
+ logevent("Trying to enable encryption...");
+
+ sfree(rsabuf);
+
+ cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
+ cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
+ cipher->sesskey(session_key);
+
+ crWaitUntil(ispkt);
+
+ if (pktin.type != SSH1_SMSG_SUCCESS) {
+ bombout(("Encryption not successfully enabled"));
+ crReturn(0);
+ }
+
+ logevent("Successfully started encryption");
fflush(stdout);
{
- static char username[100];
static int pos = 0;
static char c;
- if ((flags & FLAG_CONNECTION) && !*cfg.username) {
- c_write("login as: ", 10);
- while (pos >= 0) {
- crWaitUntil(!ispkt);
- while (inlen--) switch (c = *in++) {
- case 10: case 13:
- username[pos] = 0;
- pos = -1;
- break;
- case 8: case 127:
- if (pos > 0) {
- c_write("\b \b", 3);
- pos--;
- }
- break;
- case 21: case 27:
- while (pos > 0) {
- c_write("\b \b", 3);
- pos--;
- }
- break;
- case 3: case 4:
- random_save_seed();
- exit(0);
- break;
- default:
- if (((c >= ' ' && c <= '~') ||
- ((unsigned char)c >= 160)) && pos < 40) {
- username[pos++] = c;
- c_write(&c, 1);
- }
- break;
+ if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
+ if (ssh_get_line) {
+ if (!ssh_get_line("login as: ",
+ username, sizeof(username), FALSE)) {
+ /*
+ * get_line failed to get a username.
+ * Terminate.
+ */
+ logevent("No username provided. Abandoning session.");
+ ssh_state = SSH_STATE_CLOSED;
+ crReturn(1);
+ }
+ } else {
+ c_write_str("login as: ");
+ ssh_send_ok = 1;
+ while (pos >= 0) {
+ crWaitUntil(!ispkt);
+ while (inlen--)
+ switch (c = *in++) {
+ case 10:
+ case 13:
+ username[pos] = 0;
+ pos = -1;
+ break;
+ case 8:
+ case 127:
+ if (pos > 0) {
+ c_write_str("\b \b");
+ pos--;
+ }
+ break;
+ case 21:
+ case 27:
+ while (pos > 0) {
+ c_write_str("\b \b");
+ pos--;
+ }
+ break;
+ case 3:
+ case 4:
+ cleanup_exit(0);
+ break;
+ default:
+ if (((c >= ' ' && c <= '~') ||
+ ((unsigned char) c >= 160))
+ && pos < sizeof(username)-1) {
+ username[pos++] = c;
+ c_write(&c, 1);
+ }
+ break;
+ }
}
+ c_write_str("\r\n");
+ username[strcspn(username, "\n\r")] = '\0';
}
- c_write("\r\n", 2);
- username[strcspn(username, "\n\r")] = '\0';
} else {
- char stuff[200];
strncpy(username, cfg.username, 99);
username[99] = '\0';
- if (flags & FLAG_VERBOSE) {
- sprintf(stuff, "Sent username \"%s\".\r\n", username);
- c_write(stuff, strlen(stuff));
- }
}
send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
{
- char userlog[20+sizeof(username)];
+ char userlog[22 + sizeof(username)];
sprintf(userlog, "Sent username \"%s\"", username);
logevent(userlog);
+ if (flags & FLAG_INTERACTIVE &&
+ (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
+ strcat(userlog, "\r\n");
+ c_write_str(userlog);
+ }
}
}
crWaitUntil(ispkt);
- tried_publickey = 0;
+ if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
+ /* We must not attempt PK auth. Pretend we've already tried it. */
+ tried_publickey = tried_agent = 1;
+ } else {
+ tried_publickey = tried_agent = 0;
+ }
+ tis_auth_refused = ccard_auth_refused = 0;
+ /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
+ if (*cfg.keyfile) {
+ if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
+ publickey_blob = NULL;
+ } else
+ publickey_blob = NULL;
while (pktin.type == SSH1_SMSG_FAILURE) {
static char password[100];
+ static char prompt[200];
static int pos;
static char c;
- static int pwpkt_type;
- /*
- * Show password prompt, having first obtained it via a TIS
- * or CryptoCard exchange if we're doing TIS or CryptoCard
- * authentication.
- */
- pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
- if (agent_exists()) {
- /*
- * Attempt RSA authentication using Pageant.
- */
- static unsigned char request[5], *response, *p;
- static int responselen;
- static int i, nkeys;
- static int authed = FALSE;
- void *r;
-
- logevent("Pageant is running. Requesting keys.");
-
- /* Request the keys held by the agent. */
- PUT_32BIT(request, 1);
- request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
- agent_query(request, 5, &r, &responselen);
- response = (unsigned char *)r;
- if (response) {
- p = response + 5;
- nkeys = GET_32BIT(p); p += 4;
- { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
- logevent(buf); }
- for (i = 0; i < nkeys; i++) {
- static struct RSAKey key;
- static Bignum challenge;
-
- { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
- logevent(buf); }
- p += 4;
- p += ssh1_read_bignum(p, &key.exponent);
- p += ssh1_read_bignum(p, &key.modulus);
- send_packet(SSH1_CMSG_AUTH_RSA,
- PKT_BIGNUM, key.modulus, PKT_END);
- crWaitUntil(ispkt);
- if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
- logevent("Key refused");
- continue;
- }
- logevent("Received RSA challenge");
- ssh1_read_bignum(pktin.body, &challenge);
- {
- char *agentreq, *q, *ret;
- int len, retlen;
- len = 1 + 4; /* message type, bit count */
- len += ssh1_bignum_length(key.exponent);
- len += ssh1_bignum_length(key.modulus);
- len += ssh1_bignum_length(challenge);
- len += 16; /* session id */
- len += 4; /* response format */
- agentreq = malloc(4 + len);
- PUT_32BIT(agentreq, len);
- q = agentreq + 4;
- *q++ = SSH_AGENTC_RSA_CHALLENGE;
- PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
- q += 4;
- q += ssh1_write_bignum(q, key.exponent);
- q += ssh1_write_bignum(q, key.modulus);
- q += ssh1_write_bignum(q, challenge);
- memcpy(q, session_id, 16); q += 16;
- PUT_32BIT(q, 1); /* response format */
- agent_query(agentreq, len+4, &ret, &retlen);
- free(agentreq);
- if (ret) {
- if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
- logevent("Sending Pageant's response");
- send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
- PKT_DATA, ret+5, 16, PKT_END);
- free(ret);
- crWaitUntil(ispkt);
- if (pktin.type == SSH1_SMSG_SUCCESS) {
- logevent("Pageant's response accepted");
- authed = TRUE;
- } else
- logevent("Pageant's response not accepted");
- } else {
- logevent("Pageant failed to answer challenge");
- free(ret);
- }
- } else {
- logevent("No reply received from Pageant");
- }
- }
- freebn(key.exponent);
- freebn(key.modulus);
- freebn(challenge);
- if (authed)
- break;
- }
- }
- if (authed)
- break;
- }
- if (*cfg.keyfile && !tried_publickey)
- pwpkt_type = SSH1_CMSG_AUTH_RSA;
+ static int pwpkt_type;
+ pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
+
+ if (agent_exists() && !tried_agent) {
+ /*
+ * Attempt RSA authentication using Pageant.
+ */
+ static unsigned char request[5], *response, *p;
+ static int responselen;
+ static int i, nkeys;
+ static int authed = FALSE;
+ void *r;
+
+ tried_agent = 1;
+ logevent("Pageant is running. Requesting keys.");
+
+ /* Request the keys held by the agent. */
+ PUT_32BIT(request, 1);
+ request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
+ agent_query(request, 5, &r, &responselen);
+ response = (unsigned char *) r;
+ if (response && responselen >= 5 &&
+ response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
+ p = response + 5;
+ nkeys = GET_32BIT(p);
+ p += 4;
+ {
+ char buf[64];
+ sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
+ logevent(buf);
+ }
+ for (i = 0; i < nkeys; i++) {
+ static struct RSAKey key;
+ static Bignum challenge;
+ static char *commentp;
+ static int commentlen;
+
+ {
+ char buf[64];
+ sprintf(buf, "Trying Pageant key #%d", i);
+ logevent(buf);
+ }
+ if (publickey_blob &&
+ !memcmp(p, publickey_blob, publickey_bloblen)) {
+ logevent("This key matches configured key file");
+ tried_publickey = 1;
+ }
+ p += 4;
+ p += ssh1_read_bignum(p, &key.exponent);
+ p += ssh1_read_bignum(p, &key.modulus);
+ commentlen = GET_32BIT(p);
+ p += 4;
+ commentp = p;
+ p += commentlen;
+ send_packet(SSH1_CMSG_AUTH_RSA,
+ PKT_BIGNUM, key.modulus, PKT_END);
+ crWaitUntil(ispkt);
+ if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
+ logevent("Key refused");
+ continue;
+ }
+ logevent("Received RSA challenge");
+ ssh1_read_bignum(pktin.body, &challenge);
+ {
+ char *agentreq, *q, *ret;
+ void *vret;
+ int len, retlen;
+ len = 1 + 4; /* message type, bit count */
+ len += ssh1_bignum_length(key.exponent);
+ len += ssh1_bignum_length(key.modulus);
+ len += ssh1_bignum_length(challenge);
+ len += 16; /* session id */
+ len += 4; /* response format */
+ agentreq = smalloc(4 + len);
+ PUT_32BIT(agentreq, len);
+ q = agentreq + 4;
+ *q++ = SSH1_AGENTC_RSA_CHALLENGE;
+ PUT_32BIT(q, bignum_bitcount(key.modulus));
+ q += 4;
+ q += ssh1_write_bignum(q, key.exponent);
+ q += ssh1_write_bignum(q, key.modulus);
+ q += ssh1_write_bignum(q, challenge);
+ memcpy(q, session_id, 16);
+ q += 16;
+ PUT_32BIT(q, 1); /* response format */
+ agent_query(agentreq, len + 4, &vret, &retlen);
+ ret = vret;
+ sfree(agentreq);
+ if (ret) {
+ if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
+ logevent("Sending Pageant's response");
+ send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
+ PKT_DATA, ret + 5, 16,
+ PKT_END);
+ sfree(ret);
+ crWaitUntil(ispkt);
+ if (pktin.type == SSH1_SMSG_SUCCESS) {
+ logevent
+ ("Pageant's response accepted");
+ if (flags & FLAG_VERBOSE) {
+ c_write_str
+ ("Authenticated using RSA key \"");
+ c_write(commentp, commentlen);
+ c_write_str("\" from agent\r\n");
+ }
+ authed = TRUE;
+ } else
+ logevent
+ ("Pageant's response not accepted");
+ } else {
+ logevent
+ ("Pageant failed to answer challenge");
+ sfree(ret);
+ }
+ } else {
+ logevent("No reply received from Pageant");
+ }
+ }
+ freebn(key.exponent);
+ freebn(key.modulus);
+ freebn(challenge);
+ if (authed)
+ break;
+ }
+ }
+ if (authed)
+ break;
+ }
+ if (*cfg.keyfile && !tried_publickey)
+ pwpkt_type = SSH1_CMSG_AUTH_RSA;
+
+ if (cfg.try_tis_auth &&
+ (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
+ !tis_auth_refused) {
+ pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
+ logevent("Requested TIS authentication");
+ send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
+ crWaitUntil(ispkt);
+ if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
+ logevent("TIS authentication declined");
+ if (flags & FLAG_INTERACTIVE)
+ c_write_str("TIS authentication refused.\r\n");
+ tis_auth_refused = 1;
+ continue;
+ } else {
+ int challengelen = ((pktin.body[0] << 24) |
+ (pktin.body[1] << 16) |
+ (pktin.body[2] << 8) |
+ (pktin.body[3]));
+ logevent("Received TIS challenge");
+ if (challengelen > sizeof(prompt) - 1)
+ challengelen = sizeof(prompt) - 1; /* prevent overrun */
+ memcpy(prompt, pktin.body + 4, challengelen);
+ /* Prompt heuristic comes from OpenSSH */
+ strncpy(prompt + challengelen,
+ memchr(prompt, '\n', challengelen) ?
+ "": "\r\nResponse: ",
+ (sizeof prompt) - challengelen);
+ prompt[(sizeof prompt) - 1] = '\0';
+ }
+ }
+ if (cfg.try_tis_auth &&
+ (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
+ !ccard_auth_refused) {
+ pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
+ logevent("Requested CryptoCard authentication");
+ send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
+ crWaitUntil(ispkt);
+ if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
+ logevent("CryptoCard authentication declined");
+ c_write_str("CryptoCard authentication refused.\r\n");
+ ccard_auth_refused = 1;
+ continue;
+ } else {
+ int challengelen = ((pktin.body[0] << 24) |
+ (pktin.body[1] << 16) |
+ (pktin.body[2] << 8) |
+ (pktin.body[3]));
+ logevent("Received CryptoCard challenge");
+ if (challengelen > sizeof(prompt) - 1)
+ challengelen = sizeof(prompt) - 1; /* prevent overrun */
+ memcpy(prompt, pktin.body + 4, challengelen);
+ strncpy(prompt + challengelen,
+ memchr(prompt, '\n', challengelen) ?
+ "" : "\r\nResponse: ",
+ sizeof(prompt) - challengelen);
+ prompt[sizeof(prompt) - 1] = '\0';
+ }
+ }
+ if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
+ sprintf(prompt, "%.90s@%.90s's password: ",
+ username, savedhost);
+ }
+ if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
+ char *comment = NULL;
+ if (flags & FLAG_VERBOSE)
+ c_write_str("Trying public key authentication.\r\n");
+ if (!rsakey_encrypted(cfg.keyfile, &comment)) {
+ if (flags & FLAG_VERBOSE)
+ c_write_str("No passphrase required.\r\n");
+ goto tryauth;
+ }
+ sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
+ sfree(comment);
+ }
- if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD && !FLAG_WINDOWED) {
- char prompt[200];
- sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
- if (!ssh_get_password(prompt, password, sizeof(password))) {
- /*
- * get_password failed to get a password (for
- * example because one was supplied on the command
- * line which has already failed to work).
- * Terminate.
- */
- logevent("No more passwords to try");
- ssh_state = SSH_STATE_CLOSED;
- crReturn(1);
- }
+ /*
+ * Show password prompt, having first obtained it via a TIS
+ * or CryptoCard exchange if we're doing TIS or CryptoCard
+ * authentication.
+ */
+ if (ssh_get_line) {
+ if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
+ /*
+ * get_line failed to get a password (for example
+ * because one was supplied on the command line
+ * which has already failed to work). Terminate.
+ */
+ send_packet(SSH1_MSG_DISCONNECT,
+ PKT_STR, "No more passwords available to try",
+ PKT_END);
+ connection_fatal("Unable to authenticate");
+ ssh_state = SSH_STATE_CLOSED;
+ crReturn(1);
+ }
} else {
+ /* Prompt may have come from server. We've munged it a bit, so
+ * we know it to be zero-terminated at least once. */
+ c_write_untrusted(prompt, strlen(prompt));
+ pos = 0;
+ ssh_send_ok = 1;
+ while (pos >= 0) {
+ crWaitUntil(!ispkt);
+ while (inlen--)
+ switch (c = *in++) {
+ case 10:
+ case 13:
+ password[pos] = 0;
+ pos = -1;
+ break;
+ case 8:
+ case 127:
+ if (pos > 0)
+ pos--;
+ break;
+ case 21:
+ case 27:
+ pos = 0;
+ break;
+ case 3:
+ case 4:
+ cleanup_exit(0);
+ break;
+ default:
+ if (pos < sizeof(password)-1)
+ password[pos++] = c;
+ break;
+ }
+ }
+ c_write_str("\r\n");
+ }
- if (pktin.type == SSH1_SMSG_FAILURE &&
- cfg.try_tis_auth &&
- (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
- pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
- logevent("Requested TIS authentication");
- send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
- crWaitUntil(ispkt);
- if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
- logevent("TIS authentication declined");
- c_write("TIS authentication refused.\r\n", 29);
- } else {
- int challengelen = ((pktin.body[0] << 24) |
- (pktin.body[1] << 16) |
- (pktin.body[2] << 8) |
- (pktin.body[3]));
- logevent("Received TIS challenge");
- c_write(pktin.body+4, challengelen);
- }
- }
- if (pktin.type == SSH1_SMSG_FAILURE &&
- cfg.try_tis_auth &&
- (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
- pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
- logevent("Requested CryptoCard authentication");
- send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
- crWaitUntil(ispkt);
- if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
- logevent("CryptoCard authentication declined");
- c_write("CryptoCard authentication refused.\r\n", 29);
- } else {
- int challengelen = ((pktin.body[0] << 24) |
- (pktin.body[1] << 16) |
- (pktin.body[2] << 8) |
- (pktin.body[3]));
- logevent("Received CryptoCard challenge");
- c_write(pktin.body+4, challengelen);
- c_write("\r\nResponse : ", 13);
- }
- }
- if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD)
- c_write("password: ", 10);
- if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
- if (flags & FLAG_VERBOSE)
- c_write("Trying public key authentication.\r\n", 35);
- if (!rsakey_encrypted(cfg.keyfile)) {
- if (flags & FLAG_VERBOSE)
- c_write("No passphrase required.\r\n", 25);
- goto tryauth;
- }
- c_write("passphrase: ", 12);
- }
+ tryauth:
+ if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
+ /*
+ * Try public key authentication with the specified
+ * key file.
+ */
+ static struct RSAKey pubkey;
+ static Bignum challenge, response;
+ static int i;
+ static unsigned char buffer[32];
+
+ tried_publickey = 1;
+ i = loadrsakey(cfg.keyfile, &pubkey, password);
+ if (i == 0) {
+ c_write_str("Couldn't load private key from ");
+ c_write_str(cfg.keyfile);
+ c_write_str(".\r\n");
+ continue; /* go and try password */
+ }
+ if (i == -1) {
+ c_write_str("Wrong passphrase.\r\n");
+ tried_publickey = 0;
+ continue; /* try again */
+ }
- pos = 0;
- while (pos >= 0) {
- crWaitUntil(!ispkt);
- while (inlen--) switch (c = *in++) {
- case 10: case 13:
- password[pos] = 0;
- pos = -1;
- break;
- case 8: case 127:
- if (pos > 0)
- pos--;
- break;
- case 21: case 27:
- pos = 0;
- break;
- case 3: case 4:
- random_save_seed();
- exit(0);
- break;
- default:
- if (((c >= ' ' && c <= '~') ||
- ((unsigned char)c >= 160)) && pos < sizeof(password))
- password[pos++] = c;
- break;
- }
- }
- c_write("\r\n", 2);
+ /*
+ * Send a public key attempt.
+ */
+ send_packet(SSH1_CMSG_AUTH_RSA,
+ PKT_BIGNUM, pubkey.modulus, PKT_END);
- }
+ crWaitUntil(ispkt);
+ if (pktin.type == SSH1_SMSG_FAILURE) {
+ c_write_str("Server refused our public key.\r\n");
+ continue; /* go and try password */
+ }
+ if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
+ bombout(("Bizarre response to offer of public key"));
+ crReturn(0);
+ }
+ ssh1_read_bignum(pktin.body, &challenge);
+ response = rsadecrypt(challenge, &pubkey);
+ freebn(pubkey.private_exponent); /* burn the evidence */
- tryauth:
- if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
- /*
- * Try public key authentication with the specified
- * key file.
- */
- static struct RSAKey pubkey;
- static Bignum challenge, response;
- static int i;
- static unsigned char buffer[32];
-
- tried_publickey = 1;
- i = loadrsakey(cfg.keyfile, &pubkey, password);
- if (i == 0) {
- c_write("Couldn't load public key from ", 30);
- c_write(cfg.keyfile, strlen(cfg.keyfile));
- c_write(".\r\n", 3);
- continue; /* go and try password */
- }
- if (i == -1) {
- c_write("Wrong passphrase.\r\n", 19);
- tried_publickey = 0;
- continue; /* try again */
- }
+ for (i = 0; i < 32; i++) {
+ buffer[i] = bignum_byte(response, 31 - i);
+ }
- /*
- * Send a public key attempt.
- */
- send_packet(SSH1_CMSG_AUTH_RSA,
- PKT_BIGNUM, pubkey.modulus, PKT_END);
-
- crWaitUntil(ispkt);
- if (pktin.type == SSH1_SMSG_FAILURE) {
- if (flags & FLAG_VERBOSE)
- c_write("Server refused our public key.\r\n", 32);
- continue; /* go and try password */
- }
- if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE)
- fatalbox("Bizarre response to offer of public key");
- ssh1_read_bignum(pktin.body, &challenge);
- response = rsadecrypt(challenge, &pubkey);
- freebn(pubkey.private_exponent); /* burn the evidence */
-
- for (i = 0; i < 32; i += 2) {
- buffer[i] = response[16-i/2] >> 8;
- buffer[i+1] = response[16-i/2] & 0xFF;
- }
+ MD5Init(&md5c);
+ MD5Update(&md5c, buffer, 32);
+ MD5Update(&md5c, session_id, 16);
+ MD5Final(buffer, &md5c);
+
+ send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
+ PKT_DATA, buffer, 16, PKT_END);
+
+ crWaitUntil(ispkt);
+ if (pktin.type == SSH1_SMSG_FAILURE) {
+ if (flags & FLAG_VERBOSE)
+ c_write_str
+ ("Failed to authenticate with our public key.\r\n");
+ continue; /* go and try password */
+ } else if (pktin.type != SSH1_SMSG_SUCCESS) {
+ bombout(
+ ("Bizarre response to RSA authentication response"));
+ crReturn(0);
+ }
- MD5Init(&md5c);
- MD5Update(&md5c, buffer, 32);
- MD5Update(&md5c, session_id, 16);
- MD5Final(buffer, &md5c);
-
- send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
- PKT_DATA, buffer, 16, PKT_END);
-
- crWaitUntil(ispkt);
- if (pktin.type == SSH1_SMSG_FAILURE) {
- if (flags & FLAG_VERBOSE)
- c_write("Failed to authenticate with our public key.\r\n",
- 45);
- continue; /* go and try password */
- } else if (pktin.type != SSH1_SMSG_SUCCESS) {
- fatalbox("Bizarre response to RSA authentication response");
- }
+ break; /* we're through! */
+ } else {
+ if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
+ /*
+ * Defence against traffic analysis: we send a
+ * whole bunch of packets containing strings of
+ * different lengths. One of these strings is the
+ * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
+ * The others are all random data in
+ * SSH1_MSG_IGNORE packets. This way a passive
+ * listener can't tell which is the password, and
+ * hence can't deduce the password length.
+ *
+ * Anybody with a password length greater than 16
+ * bytes is going to have enough entropy in their
+ * password that a listener won't find it _that_
+ * much help to know how long it is. So what we'll
+ * do is:
+ *
+ * - if password length < 16, we send 15 packets
+ * containing string lengths 1 through 15
+ *
+ * - otherwise, we let N be the nearest multiple
+ * of 8 below the password length, and send 8
+ * packets containing string lengths N through
+ * N+7. This won't obscure the order of
+ * magnitude of the password length, but it will
+ * introduce a bit of extra uncertainty.
+ *
+ * A few servers (the old 1.2.18 through 1.2.22)
+ * can't deal with SSH1_MSG_IGNORE. For these
+ * servers, we need an alternative defence. We make
+ * use of the fact that the password is interpreted
+ * as a C string: so we can append a NUL, then some
+ * random data.
+ *
+ * One server (a Cisco one) can deal with neither
+ * SSH1_MSG_IGNORE _nor_ a padded password string.
+ * For this server we are left with no defences
+ * against password length sniffing.
+ */
+ if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
+ /*
+ * The server can deal with SSH1_MSG_IGNORE, so
+ * we can use the primary defence.
+ */
+ int bottom, top, pwlen, i;
+ char *randomstr;
+
+ pwlen = strlen(password);
+ if (pwlen < 16) {
+ bottom = 0; /* zero length passwords are OK! :-) */
+ top = 15;
+ } else {
+ bottom = pwlen & ~7;
+ top = bottom + 7;
+ }
- break; /* we're through! */
- } else {
- send_packet(pwpkt_type, PKT_STR, password, PKT_END);
- }
+ assert(pwlen >= bottom && pwlen <= top);
+
+ randomstr = smalloc(top + 1);
+
+ for (i = bottom; i <= top; i++) {
+ if (i == pwlen)
+ defer_packet(pwpkt_type, PKT_STR, password,
+ PKT_END);
+ else {
+ for (j = 0; j < i; j++) {
+ do {
+ randomstr[j] = random_byte();
+ } while (randomstr[j] == '\0');
+ }
+ randomstr[i] = '\0';
+ defer_packet(SSH1_MSG_IGNORE,
+ PKT_STR, randomstr, PKT_END);
+ }
+ }
+ logevent("Sending password with camouflage packets");
+ ssh_pkt_defersend();
+ }
+ else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
+ /*
+ * The server can't deal with SSH1_MSG_IGNORE
+ * but can deal with padded passwords, so we
+ * can use the secondary defence.
+ */
+ char string[64];
+ char *s;
+ int len;
+
+ len = strlen(password);
+ if (len < sizeof(string)) {
+ s = string;
+ strcpy(string, password);
+ len++; /* cover the zero byte */
+ while (len < sizeof(string)) {
+ string[len++] = (char) random_byte();
+ }
+ } else {
+ s = password;
+ }
+ logevent("Sending length-padded password");
+ send_packet(pwpkt_type, PKT_INT, len,
+ PKT_DATA, s, len, PKT_END);
+ } else {
+ /*
+ * The server has _both_
+ * BUG_CHOKES_ON_SSH1_IGNORE and
+ * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
+ * therefore nothing we can do.
+ */
+ int len;
+ len = strlen(password);
+ logevent("Sending unpadded password");
+ send_packet(pwpkt_type, PKT_INT, len,
+ PKT_DATA, password, len, PKT_END);
+ }
+ } else {
+ send_packet(pwpkt_type, PKT_STR, password, PKT_END);
+ }
+ }
logevent("Sent password");
memset(password, 0, strlen(password));
crWaitUntil(ispkt);
if (pktin.type == SSH1_SMSG_FAILURE) {
- if (flags & FLAG_VERBOSE)
- c_write("Access denied\r\n", 15);
+ if (flags & FLAG_VERBOSE)
+ c_write_str("Access denied\r\n");
logevent("Authentication refused");
} else if (pktin.type == SSH1_MSG_DISCONNECT) {
logevent("Received disconnect request");
- ssh_state = SSH_STATE_CLOSED;
+ ssh_state = SSH_STATE_CLOSED;
crReturn(1);
} else if (pktin.type != SSH1_SMSG_SUCCESS) {
- fatalbox("Strange packet received, type %d", pktin.type);
+ bombout(("Strange packet received, type %d", pktin.type));
+ crReturn(0);
}
}
crFinish(1);
}
-static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
+void sshfwd_close(struct ssh_channel *c)
+{
+ if (c && !c->closes) {
+ /*
+ * If the channel's remoteid is -1, we have sent
+ * CHANNEL_OPEN for this channel, but it hasn't even been
+ * acknowledged by the server. So we must set a close flag
+ * on it now, and then when the server acks the channel
+ * open, we can close it then.
+ */
+ if (c->remoteid != -1) {
+ if (ssh_version == 1) {
+ send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
+ PKT_END);
+ } else {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_send();
+ }
+ }
+ c->closes = 1;
+ if (c->type == CHAN_X11) {
+ c->u.x11.s = NULL;
+ logevent("Forwarded X11 connection terminated");
+ } else if (c->type == CHAN_SOCKDATA ||
+ c->type == CHAN_SOCKDATA_DORMANT) {
+ c->u.pfd.s = NULL;
+ logevent("Forwarded port closed");
+ }
+ }
+}
+
+int sshfwd_write(struct ssh_channel *c, char *buf, int len)
+{
+ if (ssh_version == 1) {
+ send_packet(SSH1_MSG_CHANNEL_DATA,
+ PKT_INT, c->remoteid,
+ PKT_INT, len, PKT_DATA, buf, len, PKT_END);
+ /*
+ * In SSH1 we can return 0 here - implying that forwarded
+ * connections are never individually throttled - because
+ * the only circumstance that can cause throttling will be
+ * the whole SSH connection backing up, in which case
+ * _everything_ will be throttled as a whole.
+ */
+ return 0;
+ } else {
+ ssh2_add_channel_data(c, buf, len);
+ return ssh2_try_send(c);
+ }
+}
+
+void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
+{
+ if (ssh_version == 1) {
+ if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
+ c->v.v1.throttling = 0;
+ ssh1_throttle(-1);
+ }
+ } else {
+ ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
+ }
+}
+
+static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
+{
crBegin;
random_init();
crReturnV;
}
if (ssh_state == SSH_STATE_CLOSED)
- crReturnV;
+ crReturnV;
+
+ if (cfg.agentfwd && agent_exists()) {
+ logevent("Requesting agent forwarding");
+ send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
+ do {
+ crReturnV;
+ } while (!ispkt);
+ if (pktin.type != SSH1_SMSG_SUCCESS
+ && pktin.type != SSH1_SMSG_FAILURE) {
+ bombout(("Protocol confusion"));
+ crReturnV;
+ } else if (pktin.type == SSH1_SMSG_FAILURE) {
+ logevent("Agent forwarding refused");
+ } else {
+ logevent("Agent forwarding enabled");
+ ssh_agentfwd_enabled = TRUE;
+ }
+ }
+
+ if (cfg.x11_forward) {
+ char proto[20], data[64];
+ logevent("Requesting X11 forwarding");
+ x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
+ if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
+ send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
+ PKT_STR, proto, PKT_STR, data,
+ PKT_INT, 0, PKT_END);
+ } else {
+ send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
+ PKT_STR, proto, PKT_STR, data, PKT_END);
+ }
+ do {
+ crReturnV;
+ } while (!ispkt);
+ if (pktin.type != SSH1_SMSG_SUCCESS
+ && pktin.type != SSH1_SMSG_FAILURE) {
+ bombout(("Protocol confusion"));
+ crReturnV;
+ } else if (pktin.type == SSH1_SMSG_FAILURE) {
+ logevent("X11 forwarding refused");
+ } else {
+ logevent("X11 forwarding enabled");
+ ssh_X11_fwd_enabled = TRUE;
+ }
+ }
- if (1 /* FIXME: agent exists && agent forwarding configured */ ) {
- logevent("Requesting agent forwarding");
- send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
- do { crReturnV; } while (!ispkt);
- if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
- fatalbox("Protocol confusion");
- } else if (pktin.type == SSH1_SMSG_FAILURE) {
- logevent("Agent forwarding refused");
- } else
- logevent("Agent forwarding enabled");
+ {
+ char type, *e;
+ int n;
+ int sport,dport;
+ char sports[256], dports[256], host[256];
+ char buf[1024];
+
+ ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
+ /* Add port forwardings. */
+ e = cfg.portfwd;
+ while (*e) {
+ type = *e++;
+ n = 0;
+ while (*e && *e != '\t')
+ sports[n++] = *e++;
+ sports[n] = 0;
+ if (*e == '\t')
+ e++;
+ n = 0;
+ while (*e && *e != ':')
+ host[n++] = *e++;
+ host[n] = 0;
+ if (*e == ':')
+ e++;
+ n = 0;
+ while (*e)
+ dports[n++] = *e++;
+ dports[n] = 0;
+ e++;
+ dport = atoi(dports);
+ sport = atoi(sports);
+ if (sport && dport) {
+ if (type == 'L') {
+ pfd_addforward(host, dport, sport);
+ sprintf(buf, "Local port %d forwarding to %s:%d",
+ sport, host, dport);
+ logevent(buf);
+ } else {
+ struct ssh_rportfwd *pf;
+ pf = smalloc(sizeof(*pf));
+ strcpy(pf->dhost, host);
+ pf->dport = dport;
+ if (add234(ssh_rportfwds, pf) != pf) {
+ sprintf(buf,
+ "Duplicate remote port forwarding to %s:%d",
+ host, dport);
+ logevent(buf);
+ sfree(pf);
+ } else {
+ sprintf(buf, "Requesting remote port %d forward to %s:%d",
+ sport, host, dport);
+ logevent(buf);
+ send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
+ PKT_INT, sport,
+ PKT_STR, host,
+ PKT_INT, dport,
+ PKT_END);
+ }
+ }
+ }
+ }
}
if (!cfg.nopty) {
send_packet(SSH1_CMSG_REQUEST_PTY,
- PKT_STR, cfg.termtype,
- PKT_INT, rows, PKT_INT, cols,
- PKT_INT, 0, PKT_INT, 0,
- PKT_CHAR, 0,
- PKT_END);
- ssh_state = SSH_STATE_INTERMED;
- do { crReturnV; } while (!ispkt);
- if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
- fatalbox("Protocol confusion");
- } else if (pktin.type == SSH1_SMSG_FAILURE) {
- c_write("Server refused to allocate pty\r\n", 32);
- }
+ PKT_STR, cfg.termtype,
+ PKT_INT, rows, PKT_INT, cols,
+ PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
+ ssh_state = SSH_STATE_INTERMED;
+ do {
+ crReturnV;
+ } while (!ispkt);
+ if (pktin.type != SSH1_SMSG_SUCCESS
+ && pktin.type != SSH1_SMSG_FAILURE) {
+ bombout(("Protocol confusion"));
+ crReturnV;
+ } else if (pktin.type == SSH1_SMSG_FAILURE) {
+ c_write_str("Server refused to allocate pty\r\n");
+ ssh_editing = ssh_echoing = 1;
+ }
logevent("Allocated pty");
+ } else {
+ ssh_editing = ssh_echoing = 1;
}
- if (*cfg.remote_cmd)
- send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
- else
- send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
- logevent("Started session");
+ if (cfg.compression) {
+ send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
+ do {
+ crReturnV;
+ } while (!ispkt);
+ if (pktin.type != SSH1_SMSG_SUCCESS
+ && pktin.type != SSH1_SMSG_FAILURE) {
+ bombout(("Protocol confusion"));
+ crReturnV;
+ } else if (pktin.type == SSH1_SMSG_FAILURE) {
+ c_write_str("Server refused to compress\r\n");
+ }
+ logevent("Started compression");
+ ssh1_compressing = TRUE;
+ zlib_compress_init();
+ zlib_decompress_init();
+ }
+
+ /*
+ * Start the shell or command.
+ *
+ * Special case: if the first-choice command is an SSH2
+ * subsystem (hence not usable here) and the second choice
+ * exists, we fall straight back to that.
+ */
+ {
+ char *cmd = cfg.remote_cmd_ptr;
+
+ if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
+ cmd = cfg.remote_cmd_ptr2;
+ ssh_fallback_cmd = TRUE;
+ }
+ if (*cmd)
+ send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
+ else
+ send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
+ logevent("Started session");
+ }
ssh_state = SSH_STATE_SESSION;
if (size_needed)
ssh_size();
+ if (eof_needed)
+ ssh_special(TS_EOF);
+ ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
ssh_send_ok = 1;
ssh_channels = newtree234(ssh_channelcmp);
while (1) {
crReturnV;
if (ispkt) {
if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
- pktin.type == SSH1_SMSG_STDERR_DATA) {
+ pktin.type == SSH1_SMSG_STDERR_DATA) {
long len = GET_32BIT(pktin.body);
- c_write(pktin.body+4, len);
+ int bufsize =
+ from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
+ pktin.body + 4, len);
+ if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
+ ssh1_stdout_throttling = 1;
+ ssh1_throttle(+1);
+ }
} else if (pktin.type == SSH1_MSG_DISCONNECT) {
- ssh_state = SSH_STATE_CLOSED;
+ ssh_state = SSH_STATE_CLOSED;
logevent("Received disconnect request");
- } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
- /* Remote side is trying to open a channel to talk to our
- * agent. Give them back a local channel number. */
- int i = 1;
- struct ssh_channel *c;
- enum234 e;
- for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
- if (c->localid > i)
- break; /* found a free number */
- i = c->localid + 1;
- }
- c = malloc(sizeof(struct ssh_channel));
- c->remoteid = GET_32BIT(pktin.body);
- c->localid = i;
- c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
- add234(ssh_channels, c);
- send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
- PKT_INT, c->remoteid, PKT_INT, c->localid,
- PKT_END);
- } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
- pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
- /* Remote side closes a channel. */
- int i = GET_32BIT(pktin.body);
- struct ssh_channel *c;
- c = find234(ssh_channels, &i, ssh_channelfind);
- if (c) {
- int closetype;
- closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
- send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
- c->closes |= closetype;
- if (c->closes == 3) {
- del234(ssh_channels, c);
- free(c);
- }
- }
- } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
- /* Data sent down one of our channels. */
- int i = GET_32BIT(pktin.body);
- int len = GET_32BIT(pktin.body+4);
- unsigned char *p = pktin.body+8;
- struct ssh_channel *c;
- c = find234(ssh_channels, &i, ssh_channelfind);
- if (c) {
- switch(c->type) {
- case SSH1_SMSG_AGENT_OPEN:
- /* Data for an agent message. Buffer it. */
- while (len > 0) {
- if (c->u.a.lensofar < 4) {
- int l = min(4 - c->u.a.lensofar, len);
- memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
- p += l; len -= l; c->u.a.lensofar += l;
- }
- if (c->u.a.lensofar == 4) {
- c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
- c->u.a.message = malloc(c->u.a.totallen);
- memcpy(c->u.a.message, c->u.a.msglen, 4);
- }
- if (c->u.a.lensofar >= 4 && len > 0) {
- int l = min(c->u.a.totallen - c->u.a.lensofar, len);
- memcpy(c->u.a.message + c->u.a.lensofar, p, l);
- p += l; len -= l; c->u.a.lensofar += l;
- }
- if (c->u.a.lensofar == c->u.a.totallen) {
- void *reply, *sentreply;
- int replylen;
- agent_query(c->u.a.message, c->u.a.totallen,
- &reply, &replylen);
- if (reply)
- sentreply = reply;
- else {
- /* Fake SSH_AGENT_FAILURE. */
- sentreply = "\0\0\0\1\5";
- replylen = 5;
- }
- send_packet(SSH1_MSG_CHANNEL_DATA,
- PKT_INT, c->remoteid,
- PKT_INT, replylen,
- PKT_DATA, sentreply, replylen,
- PKT_END);
- if (reply)
- free(reply);
- free(c->u.a.message);
- c->u.a.lensofar = 0;
- }
- }
- break;
- }
- }
+ crReturnV;
+ } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
+ /* Remote side is trying to open a channel to talk to our
+ * X-Server. Give them back a local channel number. */
+ struct ssh_channel *c;
+
+ logevent("Received X11 connect request");
+ /* Refuse if X11 forwarding is disabled. */
+ if (!ssh_X11_fwd_enabled) {
+ send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, GET_32BIT(pktin.body), PKT_END);
+ logevent("Rejected X11 connect request");
+ } else {
+ c = smalloc(sizeof(struct ssh_channel));
+
+ if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
+ logevent("opening X11 forward connection failed");
+ sfree(c);
+ send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, GET_32BIT(pktin.body),
+ PKT_END);
+ } else {
+ logevent
+ ("opening X11 forward connection succeeded");
+ c->remoteid = GET_32BIT(pktin.body);
+ c->localid = alloc_channel_id();
+ c->closes = 0;
+ c->v.v1.throttling = 0;
+ c->type = CHAN_X11; /* identify channel type */
+ add234(ssh_channels, c);
+ send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
+ PKT_INT, c->remoteid, PKT_INT,
+ c->localid, PKT_END);
+ logevent("Opened X11 forward channel");
+ }
+ }
+ } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
+ /* Remote side is trying to open a channel to talk to our
+ * agent. Give them back a local channel number. */
+ struct ssh_channel *c;
+
+ /* Refuse if agent forwarding is disabled. */
+ if (!ssh_agentfwd_enabled) {
+ send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, GET_32BIT(pktin.body), PKT_END);
+ } else {
+ c = smalloc(sizeof(struct ssh_channel));
+ c->remoteid = GET_32BIT(pktin.body);
+ c->localid = alloc_channel_id();
+ c->closes = 0;
+ c->v.v1.throttling = 0;
+ c->type = CHAN_AGENT; /* identify channel type */
+ c->u.a.lensofar = 0;
+ add234(ssh_channels, c);
+ send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
+ PKT_INT, c->remoteid, PKT_INT, c->localid,
+ PKT_END);
+ }
+ } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
+ /* Remote side is trying to open a channel to talk to a
+ * forwarded port. Give them back a local channel number. */
+ struct ssh_channel *c;
+ struct ssh_rportfwd pf;
+ int hostsize, port;
+ char host[256], buf[1024];
+ char *p, *h, *e;
+ c = smalloc(sizeof(struct ssh_channel));
+
+ hostsize = GET_32BIT(pktin.body+4);
+ for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
+ if (h+1 < host+sizeof(host))
+ *h++ = *p;
+ p++;
+ }
+ *h = 0;
+ port = GET_32BIT(p);
+
+ strcpy(pf.dhost, host);
+ pf.dport = port;
+
+ if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
+ sprintf(buf, "Rejected remote port open request for %s:%d",
+ host, port);
+ logevent(buf);
+ send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, GET_32BIT(pktin.body), PKT_END);
+ } else {
+ sprintf(buf, "Received remote port open request for %s:%d",
+ host, port);
+ logevent(buf);
+ e = pfd_newconnect(&c->u.pfd.s, host, port, c);
+ if (e != NULL) {
+ char buf[256];
+ sprintf(buf, "Port open failed: %s", e);
+ logevent(buf);
+ sfree(c);
+ send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, GET_32BIT(pktin.body),
+ PKT_END);
+ } else {
+ c->remoteid = GET_32BIT(pktin.body);
+ c->localid = alloc_channel_id();
+ c->closes = 0;
+ c->v.v1.throttling = 0;
+ c->type = CHAN_SOCKDATA; /* identify channel type */
+ add234(ssh_channels, c);
+ send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
+ PKT_INT, c->remoteid, PKT_INT,
+ c->localid, PKT_END);
+ logevent("Forwarded port opened successfully");
+ }
+ }
+
+ } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
+ unsigned int remoteid = GET_32BIT(pktin.body);
+ unsigned int localid = GET_32BIT(pktin.body+4);
+ struct ssh_channel *c;
+
+ c = find234(ssh_channels, &remoteid, ssh_channelfind);
+ if (c && c->type == CHAN_SOCKDATA_DORMANT) {
+ c->remoteid = localid;
+ c->type = CHAN_SOCKDATA;
+ c->v.v1.throttling = 0;
+ pfd_confirm(c->u.pfd.s);
+ }
+
+ if (c && c->closes) {
+ /*
+ * We have a pending close on this channel,
+ * which we decided on before the server acked
+ * the channel open. So now we know the
+ * remoteid, we can close it again.
+ */
+ send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
+ PKT_END);
+ }
+
+ } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
+ unsigned int remoteid = GET_32BIT(pktin.body);
+ unsigned int localid = GET_32BIT(pktin.body+4);
+ struct ssh_channel *c;
+
+ c = find234(ssh_channels, &remoteid, ssh_channelfind);
+ if (c && c->type == CHAN_SOCKDATA_DORMANT) {
+ logevent("Forwarded connection refused by server");
+ pfd_close(c->u.pfd.s);
+ del234(ssh_channels, c);
+ sfree(c);
+ }
+
+ } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
+ pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
+ /* Remote side closes a channel. */
+ unsigned i = GET_32BIT(pktin.body);
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (c) {
+ int closetype;
+ closetype =
+ (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
+ if (!(c->closes & closetype))
+ send_packet(pktin.type, PKT_INT, c->remoteid,
+ PKT_END);
+ if ((c->closes == 0) && (c->type == CHAN_X11)) {
+ logevent("Forwarded X11 connection terminated");
+ assert(c->u.x11.s != NULL);
+ x11_close(c->u.x11.s);
+ c->u.x11.s = NULL;
+ }
+ if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
+ logevent("Forwarded port closed");
+ assert(c->u.pfd.s != NULL);
+ pfd_close(c->u.pfd.s);
+ c->u.pfd.s = NULL;
+ }
+ c->closes |= closetype;
+ if (c->closes == 3) {
+ del234(ssh_channels, c);
+ sfree(c);
+ }
+ }
+ } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
+ /* Data sent down one of our channels. */
+ int i = GET_32BIT(pktin.body);
+ int len = GET_32BIT(pktin.body + 4);
+ unsigned char *p = pktin.body + 8;
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (c) {
+ int bufsize;
+ switch (c->type) {
+ case CHAN_X11:
+ bufsize = x11_send(c->u.x11.s, p, len);
+ break;
+ case CHAN_SOCKDATA:
+ bufsize = pfd_send(c->u.pfd.s, p, len);
+ break;
+ case CHAN_AGENT:
+ /* Data for an agent message. Buffer it. */
+ while (len > 0) {
+ if (c->u.a.lensofar < 4) {
+ int l = min(4 - c->u.a.lensofar, len);
+ memcpy(c->u.a.msglen + c->u.a.lensofar, p,
+ l);
+ p += l;
+ len -= l;
+ c->u.a.lensofar += l;
+ }
+ if (c->u.a.lensofar == 4) {
+ c->u.a.totallen =
+ 4 + GET_32BIT(c->u.a.msglen);
+ c->u.a.message = smalloc(c->u.a.totallen);
+ memcpy(c->u.a.message, c->u.a.msglen, 4);
+ }
+ if (c->u.a.lensofar >= 4 && len > 0) {
+ int l =
+ min(c->u.a.totallen - c->u.a.lensofar,
+ len);
+ memcpy(c->u.a.message + c->u.a.lensofar, p,
+ l);
+ p += l;
+ len -= l;
+ c->u.a.lensofar += l;
+ }
+ if (c->u.a.lensofar == c->u.a.totallen) {
+ void *reply, *sentreply;
+ int replylen;
+ agent_query(c->u.a.message,
+ c->u.a.totallen, &reply,
+ &replylen);
+ if (reply)
+ sentreply = reply;
+ else {
+ /* Fake SSH_AGENT_FAILURE. */
+ sentreply = "\0\0\0\1\5";
+ replylen = 5;
+ }
+ send_packet(SSH1_MSG_CHANNEL_DATA,
+ PKT_INT, c->remoteid,
+ PKT_INT, replylen,
+ PKT_DATA, sentreply, replylen,
+ PKT_END);
+ if (reply)
+ sfree(reply);
+ sfree(c->u.a.message);
+ c->u.a.lensofar = 0;
+ }
+ }
+ bufsize = 0; /* agent channels never back up */
+ break;
+ }
+ if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
+ c->v.v1.throttling = 1;
+ ssh1_throttle(+1);
+ }
+ }
} else if (pktin.type == SSH1_SMSG_SUCCESS) {
/* may be from EXEC_SHELL on some servers */
} else if (pktin.type == SSH1_SMSG_FAILURE) {
/* may be from EXEC_SHELL on some servers
* if no pty is available or in other odd cases. Ignore */
} else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
+ char buf[100];
+ ssh_exitcode = GET_32BIT(pktin.body);
+ sprintf(buf, "Server sent command exit status %d",
+ ssh_exitcode);
+ logevent(buf);
send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
+ /*
+ * In case `helpful' firewalls or proxies tack
+ * extra human-readable text on the end of the
+ * session which we might mistake for another
+ * encrypted packet, we close the session once
+ * we've sent EXIT_CONFIRMATION.
+ */
+ ssh_state = SSH_STATE_CLOSED;
+ crReturnV;
} else {
- fatalbox("Strange packet received: type %d", pktin.type);
+ bombout(("Strange packet received: type %d", pktin.type));
+ crReturnV;
}
} else {
- send_packet(SSH1_CMSG_STDIN_DATA,
- PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
+ while (inlen > 0) {
+ int len = min(inlen, 512);
+ send_packet(SSH1_CMSG_STDIN_DATA,
+ PKT_INT, len, PKT_DATA, in, len, PKT_END);
+ in += len;
+ inlen -= len;
+ }
}
}
/*
* Utility routine for decoding comma-separated strings in KEXINIT.
*/
-int in_commasep_string(char *needle, char *haystack, int haylen) {
+static int in_commasep_string(char *needle, char *haystack, int haylen)
+{
int needlen = strlen(needle);
while (1) {
- /*
- * Is it at the start of the string?
- */
- if (haylen >= needlen && /* haystack is long enough */
- !memcmp(needle, haystack, needlen) && /* initial match */
- (haylen == needlen || haystack[needlen] == ',')
- /* either , or EOS follows */
- )
- return 1;
- /*
- * If not, search for the next comma and resume after that.
- * If no comma found, terminate.
- */
- while (haylen > 0 && *haystack != ',')
- haylen--, haystack++;
- if (haylen == 0)
- return 0;
- haylen--, haystack++; /* skip over comma itself */
+ /*
+ * Is it at the start of the string?
+ */
+ if (haylen >= needlen && /* haystack is long enough */
+ !memcmp(needle, haystack, needlen) && /* initial match */
+ (haylen == needlen || haystack[needlen] == ',')
+ /* either , or EOS follows */
+ )
+ return 1;
+ /*
+ * If not, search for the next comma and resume after that.
+ * If no comma found, terminate.
+ */
+ while (haylen > 0 && *haystack != ',')
+ haylen--, haystack++;
+ if (haylen == 0)
+ return 0;
+ haylen--, haystack++; /* skip over comma itself */
}
}
/*
* SSH2 key creation method.
*/
-void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
+static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
+ char *keyspace)
+{
SHA_State s;
/* First 20 bytes. */
SHA_Init(&s);
sha_mpint(&s, K);
SHA_Bytes(&s, H, 20);
SHA_Bytes(&s, &chr, 1);
- SHA_Bytes(&s, H, 20);
+ SHA_Bytes(&s, sessid, 20);
SHA_Final(&s, keyspace);
/* Next 20 bytes. */
SHA_Init(&s);
sha_mpint(&s, K);
SHA_Bytes(&s, H, 20);
SHA_Bytes(&s, keyspace, 20);
- SHA_Final(&s, keyspace+20);
+ SHA_Final(&s, keyspace + 20);
}
/*
*/
static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
{
- static int i, len;
+ static int i, j, len, nbits, pbits, warn;
static char *str;
- static Bignum e, f, K;
- static struct ssh_cipher *cscipher_tobe = NULL;
- static struct ssh_cipher *sccipher_tobe = NULL;
- static struct ssh_mac *csmac_tobe = NULL;
- static struct ssh_mac *scmac_tobe = NULL;
- static struct ssh_compress *cscomp_tobe = NULL;
- static struct ssh_compress *sccomp_tobe = NULL;
- static char *hostkeydata, *sigdata, *keystr;
+ static Bignum p, g, e, f, K;
+ static int kex_init_value, kex_reply_value;
+ static const struct ssh_mac **maclist;
+ static int nmacs;
+ static const struct ssh2_cipher *cscipher_tobe = NULL;
+ static const struct ssh2_cipher *sccipher_tobe = NULL;
+ static const struct ssh_mac *csmac_tobe = NULL;
+ static const struct ssh_mac *scmac_tobe = NULL;
+ static const struct ssh_compress *cscomp_tobe = NULL;
+ static const struct ssh_compress *sccomp_tobe = NULL;
+ static char *hostkeydata, *sigdata, *keystr, *fingerprint;
static int hostkeylen, siglen;
+ static void *hkey; /* actual host key */
static unsigned char exchange_hash[20];
static unsigned char keyspace[40];
+ static int n_preferred_ciphers;
+ static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
+ static const struct ssh_compress *preferred_comp;
+ static int cipherstr_started;
+ static int first_kex;
crBegin;
random_init();
+ first_kex = 1;
+
+ /*
+ * Set up the preferred ciphers. (NULL => warn below here)
+ */
+ n_preferred_ciphers = 0;
+ for (i = 0; i < CIPHER_MAX; i++) {
+ switch (cfg.ssh_cipherlist[i]) {
+ case CIPHER_BLOWFISH:
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
+ n_preferred_ciphers++;
+ break;
+ case CIPHER_DES:
+ if (cfg.ssh2_des_cbc) {
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
+ n_preferred_ciphers++;
+ }
+ break;
+ case CIPHER_3DES:
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
+ n_preferred_ciphers++;
+ break;
+ case CIPHER_AES:
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
+ n_preferred_ciphers++;
+ break;
+ case CIPHER_WARN:
+ /* Flag for later. Don't bother if it's the last in
+ * the list. */
+ if (i < CIPHER_MAX - 1) {
+ preferred_ciphers[n_preferred_ciphers] = NULL;
+ n_preferred_ciphers++;
+ }
+ break;
+ }
+ }
- begin_key_exchange:
+ /*
+ * Set up preferred compression.
+ */
+ if (cfg.compression)
+ preferred_comp = &ssh_zlib;
+ else
+ preferred_comp = &ssh_comp_none;
+
+ /*
+ * Be prepared to work around the buggy MAC problem.
+ */
+ if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
+ maclist = buggymacs, nmacs = lenof(buggymacs);
+ else
+ maclist = macs, nmacs = lenof(macs);
+
+ begin_key_exchange:
/*
* Construct and send our key exchange packet.
*/
ssh2_pkt_init(SSH2_MSG_KEXINIT);
for (i = 0; i < 16; i++)
- ssh2_pkt_addbyte((unsigned char)random_byte());
+ ssh2_pkt_addbyte((unsigned char) random_byte());
/* List key exchange algorithms. */
ssh2_pkt_addstring_start();
for (i = 0; i < lenof(kex_algs); i++) {
- ssh2_pkt_addstring_str(kex_algs[i]->name);
- if (i < lenof(kex_algs)-1)
- ssh2_pkt_addstring_str(",");
+ ssh2_pkt_addstring_str(kex_algs[i]->name);
+ if (i < lenof(kex_algs) - 1)
+ ssh2_pkt_addstring_str(",");
}
/* List server host key algorithms. */
ssh2_pkt_addstring_start();
for (i = 0; i < lenof(hostkey_algs); i++) {
- ssh2_pkt_addstring_str(hostkey_algs[i]->name);
- if (i < lenof(hostkey_algs)-1)
- ssh2_pkt_addstring_str(",");
+ ssh2_pkt_addstring_str(hostkey_algs[i]->name);
+ if (i < lenof(hostkey_algs) - 1)
+ ssh2_pkt_addstring_str(",");
}
/* List client->server encryption algorithms. */
ssh2_pkt_addstring_start();
- for (i = 0; i < lenof(ciphers); i++) {
- ssh2_pkt_addstring_str(ciphers[i]->name);
- if (i < lenof(ciphers)-1)
- ssh2_pkt_addstring_str(",");
+ cipherstr_started = 0;
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) continue; /* warning flag */
+ for (j = 0; j < c->nciphers; j++) {
+ if (cipherstr_started)
+ ssh2_pkt_addstring_str(",");
+ ssh2_pkt_addstring_str(c->list[j]->name);
+ cipherstr_started = 1;
+ }
}
/* List server->client encryption algorithms. */
ssh2_pkt_addstring_start();
- for (i = 0; i < lenof(ciphers); i++) {
- ssh2_pkt_addstring_str(ciphers[i]->name);
- if (i < lenof(ciphers)-1)
- ssh2_pkt_addstring_str(",");
+ cipherstr_started = 0;
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) continue; /* warning flag */
+ for (j = 0; j < c->nciphers; j++) {
+ if (cipherstr_started)
+ ssh2_pkt_addstring_str(",");
+ ssh2_pkt_addstring_str(c->list[j]->name);
+ cipherstr_started = 1;
+ }
}
/* List client->server MAC algorithms. */
ssh2_pkt_addstring_start();
- for (i = 0; i < lenof(macs); i++) {
- ssh2_pkt_addstring_str(macs[i]->name);
- if (i < lenof(macs)-1)
- ssh2_pkt_addstring_str(",");
+ for (i = 0; i < nmacs; i++) {
+ ssh2_pkt_addstring_str(maclist[i]->name);
+ if (i < nmacs - 1)
+ ssh2_pkt_addstring_str(",");
}
/* List server->client MAC algorithms. */
ssh2_pkt_addstring_start();
- for (i = 0; i < lenof(macs); i++) {
- ssh2_pkt_addstring_str(macs[i]->name);
- if (i < lenof(macs)-1)
- ssh2_pkt_addstring_str(",");
+ for (i = 0; i < nmacs; i++) {
+ ssh2_pkt_addstring_str(maclist[i]->name);
+ if (i < nmacs - 1)
+ ssh2_pkt_addstring_str(",");
}
/* List client->server compression algorithms. */
ssh2_pkt_addstring_start();
- for (i = 0; i < lenof(compressions); i++) {
- ssh2_pkt_addstring_str(compressions[i]->name);
- if (i < lenof(compressions)-1)
- ssh2_pkt_addstring_str(",");
+ for (i = 0; i < lenof(compressions) + 1; i++) {
+ const struct ssh_compress *c =
+ i == 0 ? preferred_comp : compressions[i - 1];
+ ssh2_pkt_addstring_str(c->name);
+ if (i < lenof(compressions))
+ ssh2_pkt_addstring_str(",");
}
/* List server->client compression algorithms. */
ssh2_pkt_addstring_start();
- for (i = 0; i < lenof(compressions); i++) {
- ssh2_pkt_addstring_str(compressions[i]->name);
- if (i < lenof(compressions)-1)
- ssh2_pkt_addstring_str(",");
+ for (i = 0; i < lenof(compressions) + 1; i++) {
+ const struct ssh_compress *c =
+ i == 0 ? preferred_comp : compressions[i - 1];
+ ssh2_pkt_addstring_str(c->name);
+ if (i < lenof(compressions))
+ ssh2_pkt_addstring_str(",");
}
/* List client->server languages. Empty list. */
ssh2_pkt_addstring_start();
ssh2_pkt_addbool(FALSE);
/* Reserved. */
ssh2_pkt_adduint32(0);
- sha_string(&exhash, pktout.data+5, pktout.length-5);
+
+ exhash = exhashbase;
+ sha_string(&exhash, pktout.data + 5, pktout.length - 5);
+
ssh2_pkt_send();
- if (!ispkt) crWaitUntil(ispkt);
- sha_string(&exhash, pktin.data+5, pktin.length-5);
+ if (!ispkt)
+ crWaitUntil(ispkt);
+ sha_string(&exhash, pktin.data + 5, pktin.length - 5);
/*
* Now examine the other side's KEXINIT to see what we're up
* to.
*/
if (pktin.type != SSH2_MSG_KEXINIT) {
- fatalbox("expected key exchange packet from server");
+ bombout(("expected key exchange packet from server"));
+ crReturn(0);
}
- kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
- csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
- pktin.savedpos += 16; /* skip garbage cookie */
+ kex = NULL;
+ hostkey = NULL;
+ cscipher_tobe = NULL;
+ sccipher_tobe = NULL;
+ csmac_tobe = NULL;
+ scmac_tobe = NULL;
+ cscomp_tobe = NULL;
+ sccomp_tobe = NULL;
+ pktin.savedpos += 16; /* skip garbage cookie */
ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
for (i = 0; i < lenof(kex_algs); i++) {
- if (in_commasep_string(kex_algs[i]->name, str, len)) {
- kex = kex_algs[i];
- break;
- }
+ if (in_commasep_string(kex_algs[i]->name, str, len)) {
+ kex = kex_algs[i];
+ break;
+ }
}
ssh2_pkt_getstring(&str, &len); /* host key algorithms */
for (i = 0; i < lenof(hostkey_algs); i++) {
- if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
- hostkey = hostkey_algs[i];
- break;
- }
+ if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
+ hostkey = hostkey_algs[i];
+ break;
+ }
}
ssh2_pkt_getstring(&str, &len); /* client->server cipher */
- for (i = 0; i < lenof(ciphers); i++) {
- if (in_commasep_string(ciphers[i]->name, str, len)) {
- cscipher_tobe = ciphers[i];
- break;
- }
+ warn = 0;
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) {
+ warn = 1;
+ } else {
+ for (j = 0; j < c->nciphers; j++) {
+ if (in_commasep_string(c->list[j]->name, str, len)) {
+ cscipher_tobe = c->list[j];
+ break;
+ }
+ }
+ }
+ if (cscipher_tobe) {
+ if (warn)
+ askcipher(cscipher_tobe->name, 1);
+ break;
+ }
+ }
+ if (!cscipher_tobe) {
+ bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
+ crReturn(0);
}
+
ssh2_pkt_getstring(&str, &len); /* server->client cipher */
- for (i = 0; i < lenof(ciphers); i++) {
- if (in_commasep_string(ciphers[i]->name, str, len)) {
- sccipher_tobe = ciphers[i];
- break;
- }
+ warn = 0;
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) {
+ warn = 1;
+ } else {
+ for (j = 0; j < c->nciphers; j++) {
+ if (in_commasep_string(c->list[j]->name, str, len)) {
+ sccipher_tobe = c->list[j];
+ break;
+ }
+ }
+ }
+ if (sccipher_tobe) {
+ if (warn)
+ askcipher(sccipher_tobe->name, 2);
+ break;
+ }
}
+ if (!sccipher_tobe) {
+ bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
+ crReturn(0);
+ }
+
ssh2_pkt_getstring(&str, &len); /* client->server mac */
- for (i = 0; i < lenof(macs); i++) {
- if (in_commasep_string(macs[i]->name, str, len)) {
- csmac_tobe = macs[i];
- break;
- }
+ for (i = 0; i < nmacs; i++) {
+ if (in_commasep_string(maclist[i]->name, str, len)) {
+ csmac_tobe = maclist[i];
+ break;
+ }
}
ssh2_pkt_getstring(&str, &len); /* server->client mac */
- for (i = 0; i < lenof(macs); i++) {
- if (in_commasep_string(macs[i]->name, str, len)) {
- scmac_tobe = macs[i];
- break;
- }
+ for (i = 0; i < nmacs; i++) {
+ if (in_commasep_string(maclist[i]->name, str, len)) {
+ scmac_tobe = maclist[i];
+ break;
+ }
}
ssh2_pkt_getstring(&str, &len); /* client->server compression */
- for (i = 0; i < lenof(compressions); i++) {
- if (in_commasep_string(compressions[i]->name, str, len)) {
- cscomp_tobe = compressions[i];
- break;
- }
+ for (i = 0; i < lenof(compressions) + 1; i++) {
+ const struct ssh_compress *c =
+ i == 0 ? preferred_comp : compressions[i - 1];
+ if (in_commasep_string(c->name, str, len)) {
+ cscomp_tobe = c;
+ break;
+ }
}
ssh2_pkt_getstring(&str, &len); /* server->client compression */
- for (i = 0; i < lenof(compressions); i++) {
- if (in_commasep_string(compressions[i]->name, str, len)) {
- sccomp_tobe = compressions[i];
- break;
- }
+ for (i = 0; i < lenof(compressions) + 1; i++) {
+ const struct ssh_compress *c =
+ i == 0 ? preferred_comp : compressions[i - 1];
+ if (in_commasep_string(c->name, str, len)) {
+ sccomp_tobe = c;
+ break;
+ }
+ }
+
+ /*
+ * Work out the number of bits of key we will need from the key
+ * exchange. We start with the maximum key length of either
+ * cipher...
+ */
+ {
+ int csbits, scbits;
+
+ csbits = cscipher_tobe->keylen;
+ scbits = sccipher_tobe->keylen;
+ nbits = (csbits > scbits ? csbits : scbits);
}
+ /* The keys only have 160-bit entropy, since they're based on
+ * a SHA-1 hash. So cap the key size at 160 bits. */
+ if (nbits > 160)
+ nbits = 160;
/*
- * Currently we only support Diffie-Hellman and DSS, so let's
- * bomb out if those aren't selected.
+ * If we're doing Diffie-Hellman group exchange, start by
+ * requesting a group.
*/
- if (kex != &ssh_diffiehellman || hostkey != &ssh_dss)
- fatalbox("internal fault: chaos in SSH 2 transport layer");
+ if (kex == &ssh_diffiehellman_gex) {
+ logevent("Doing Diffie-Hellman group exchange");
+ ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
+ /*
+ * Work out how big a DH group we will need to allow that
+ * much data.
+ */
+ pbits = 512 << ((nbits - 1) / 64);
+ ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
+ ssh2_pkt_adduint32(pbits);
+ ssh2_pkt_send();
+ crWaitUntil(ispkt);
+ if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
+ bombout(("expected key exchange group packet from server"));
+ crReturn(0);
+ }
+ p = ssh2_pkt_getmp();
+ g = ssh2_pkt_getmp();
+ dh_setup_group(p, g);
+ kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
+ kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
+ } else {
+ ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
+ dh_setup_group1();
+ kex_init_value = SSH2_MSG_KEXDH_INIT;
+ kex_reply_value = SSH2_MSG_KEXDH_REPLY;
+ }
+
+ logevent("Doing Diffie-Hellman key exchange");
/*
- * Now we begin the fun. Generate and send e for Diffie-Hellman.
+ * Now generate and send e for Diffie-Hellman.
*/
- e = dh_create_e();
- ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
+ e = dh_create_e(nbits * 2);
+ ssh2_pkt_init(kex_init_value);
ssh2_pkt_addmp(e);
ssh2_pkt_send();
crWaitUntil(ispkt);
- if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
- fatalbox("expected key exchange packet from server");
+ if (pktin.type != kex_reply_value) {
+ bombout(("expected key exchange reply packet from server"));
+ crReturn(0);
}
ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
f = ssh2_pkt_getmp();
K = dh_find_K(f);
sha_string(&exhash, hostkeydata, hostkeylen);
+ if (kex == &ssh_diffiehellman_gex) {
+ sha_uint32(&exhash, pbits);
+ sha_mpint(&exhash, p);
+ sha_mpint(&exhash, g);
+ }
sha_mpint(&exhash, e);
sha_mpint(&exhash, f);
sha_mpint(&exhash, K);
SHA_Final(&exhash, exchange_hash);
+ dh_cleanup();
+
#if 0
- debug(("Exchange hash is:\r\n"));
- for (i = 0; i < 20; i++)
- debug((" %02x", exchange_hash[i]));
- debug(("\r\n"));
+ debug(("Exchange hash is:\n"));
+ dmemdump(exchange_hash, 20);
#endif
- hostkey->setkey(hostkeydata, hostkeylen);
- if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20))
- fatalbox("Server failed host key check");
-
- /*
- * Expect SSH2_MSG_NEWKEYS from server.
- */
- crWaitUntil(ispkt);
- if (pktin.type != SSH2_MSG_NEWKEYS)
- fatalbox("expected new-keys packet from server");
+ hkey = hostkey->newkey(hostkeydata, hostkeylen);
+ if (!hkey ||
+ !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
+ bombout(("Server's host key did not match the signature supplied"));
+ crReturn(0);
+ }
/*
* Authenticate remote host: verify host key. (We've already
* checked the signature of the exchange hash.)
*/
- keystr = hostkey->fmtkey();
- verify_ssh_host_key(savedhost, keystr);
- free(keystr);
+ keystr = hostkey->fmtkey(hkey);
+ fingerprint = hostkey->fingerprint(hkey);
+ verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
+ keystr, fingerprint);
+ if (first_kex) { /* don't bother logging this in rekeys */
+ logevent("Host key fingerprint is:");
+ logevent(fingerprint);
+ }
+ sfree(fingerprint);
+ sfree(keystr);
+ hostkey->freekey(hkey);
/*
* Send SSH2_MSG_NEWKEYS.
ssh2_pkt_send();
/*
+ * Expect SSH2_MSG_NEWKEYS from server.
+ */
+ crWaitUntil(ispkt);
+ if (pktin.type != SSH2_MSG_NEWKEYS) {
+ bombout(("expected new-keys packet from server"));
+ crReturn(0);
+ }
+
+ /*
* Create and initialise session keys.
*/
cscipher = cscipher_tobe;
scmac = scmac_tobe;
cscomp = cscomp_tobe;
sccomp = sccomp_tobe;
+ cscomp->compress_init();
+ sccomp->decompress_init();
/*
- * Set IVs after keys.
+ * Set IVs after keys. Here we use the exchange hash from the
+ * _first_ key exchange.
*/
- ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
- ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
- ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
- ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
- ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
- ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
+ if (first_kex)
+ memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
+ ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
+ cscipher->setcskey(keyspace);
+ ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
+ sccipher->setsckey(keyspace);
+ ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
+ cscipher->setcsiv(keyspace);
+ ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
+ sccipher->setsciv(keyspace);
+ ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
+ csmac->setcskey(keyspace);
+ ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
+ scmac->setsckey(keyspace);
+
+ /*
+ * If this is the first key exchange phase, we must pass the
+ * SSH2_MSG_NEWKEYS packet to the next layer, not because it
+ * wants to see it but because it will need time to initialise
+ * itself before it sees an actual packet. In subsequent key
+ * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
+ * it would only confuse the layer above.
+ */
+ if (!first_kex) {
+ crReturn(0);
+ }
+ first_kex = 0;
/*
* Now we're encrypting. Begin returning 1 to the protocol main
* transport. If we ever see a KEXINIT, we must go back to the
* start.
*/
- do {
- crReturn(1);
- } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
+ while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
+ crReturn(1);
+ }
+ logevent("Server initiated key re-exchange");
goto begin_key_exchange;
crFinish(1);
}
/*
- * SSH2: remote identifier for the main session channel.
+ * Add data to an SSH2 channel output buffer.
+ */
+static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
+ int len)
+{
+ bufchain_add(&c->v.v2.outbuffer, buf, len);
+}
+
+/*
+ * Attempt to send data on an SSH2 channel.
*/
-static unsigned long ssh_remote_channel;
+static int ssh2_try_send(struct ssh_channel *c)
+{
+ while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
+ int len;
+ void *data;
+ bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
+ if ((unsigned)len > c->v.v2.remwindow)
+ len = c->v.v2.remwindow;
+ if ((unsigned)len > c->v.v2.remmaxpkt)
+ len = c->v.v2.remmaxpkt;
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_addstring_data(data, len);
+ ssh2_pkt_send();
+ bufchain_consume(&c->v.v2.outbuffer, len);
+ c->v.v2.remwindow -= len;
+ }
+
+ /*
+ * After having sent as much data as we can, return the amount
+ * still buffered.
+ */
+ return bufchain_size(&c->v.v2.outbuffer);
+}
+
+/*
+ * Potentially enlarge the window on an SSH2 channel.
+ */
+static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
+{
+ /*
+ * Never send WINDOW_ADJUST for a channel that the remote side
+ * already thinks it's closed; there's no point, since it won't
+ * be sending any more data anyway.
+ */
+ if (c->closes != 0)
+ return;
+
+ if (newwin > c->v.v2.locwindow) {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
+ ssh2_pkt_send();
+ c->v.v2.locwindow = newwin;
+ }
+}
/*
* Handle the SSH2 userauth and connection layers.
*/
static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
{
- static unsigned long remote_winsize;
- static unsigned long remote_maxpkt;
+ static enum {
+ AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
+ AUTH_PASSWORD,
+ AUTH_KEYBOARD_INTERACTIVE
+ } method;
+ static enum {
+ AUTH_TYPE_NONE,
+ AUTH_TYPE_PUBLICKEY,
+ AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
+ AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
+ AUTH_TYPE_PASSWORD,
+ AUTH_TYPE_KEYBOARD_INTERACTIVE,
+ AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
+ } type;
+ static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
+ static int tried_pubkey_config, tried_agent, tried_keyb_inter;
+ static int kbd_inter_running;
+ static int we_are_in;
+ static int num_prompts, echo;
+ static char username[100];
+ static char pwprompt[200];
+ static char password[100];
+ static void *publickey_blob;
+ static int publickey_bloblen;
crBegin;
ssh2_pkt_addstring("ssh-userauth");
ssh2_pkt_send();
crWaitUntilV(ispkt);
- if (pktin.type != SSH2_MSG_SERVICE_ACCEPT)
- fatalbox("Server refused user authentication protocol");
+ if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
+ bombout(("Server refused user authentication protocol"));
+ crReturnV;
+ }
/*
- * FIXME: currently we support only password authentication.
- * (This places us technically in violation of the SSH2 spec.
- * We must fix this.)
+ * We repeat this whole loop, including the username prompt,
+ * until we manage a successful authentication. If the user
+ * types the wrong _password_, they are sent back to the
+ * beginning to try another username. (If they specify a
+ * username in the config, they are never asked, even if they
+ * do give a wrong password.)
+ *
+ * I think this best serves the needs of
+ *
+ * - the people who have no configuration, no keys, and just
+ * want to try repeated (username,password) pairs until they
+ * type both correctly
+ *
+ * - people who have keys and configuration but occasionally
+ * need to fall back to passwords
+ *
+ * - people with a key held in Pageant, who might not have
+ * logged in to a particular machine before; so they want to
+ * type a username, and then _either_ their key will be
+ * accepted, _or_ they will type a password. If they mistype
+ * the username they will want to be able to get back and
+ * retype it!
*/
- while (1) {
- /*
- * Get a username and a password.
- */
- static char username[100];
- static char password[100];
- static int pos = 0;
+ username[0] = '\0';
+ do {
+ static int pos;
static char c;
- if ((flags & FLAG_CONNECTION) && !*cfg.username) {
- c_write("login as: ", 10);
- while (pos >= 0) {
- crWaitUntilV(!ispkt);
- while (inlen--) switch (c = *in++) {
- case 10: case 13:
- username[pos] = 0;
- pos = -1;
- break;
- case 8: case 127:
- if (pos > 0) {
- c_write("\b \b", 3);
- pos--;
- }
- break;
- case 21: case 27:
- while (pos > 0) {
- c_write("\b \b", 3);
- pos--;
- }
- break;
- case 3: case 4:
- random_save_seed();
- exit(0);
- break;
- default:
- if (((c >= ' ' && c <= '~') ||
- ((unsigned char)c >= 160)) && pos < 40) {
- username[pos++] = c;
- c_write(&c, 1);
- }
- break;
+ /*
+ * Get a username.
+ */
+ pos = 0;
+ if (*username && !cfg.change_username) {
+ /*
+ * We got a username last time round this loop, and
+ * with change_username turned off we don't try to get
+ * it again.
+ */
+ } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
+ if (ssh_get_line) {
+ if (!ssh_get_line("login as: ",
+ username, sizeof(username), FALSE)) {
+ /*
+ * get_line failed to get a username.
+ * Terminate.
+ */
+ logevent("No username provided. Abandoning session.");
+ ssh_state = SSH_STATE_CLOSED;
+ crReturnV;
+ }
+ } else {
+ c_write_str("login as: ");
+ ssh_send_ok = 1;
+ while (pos >= 0) {
+ crWaitUntilV(!ispkt);
+ while (inlen--)
+ switch (c = *in++) {
+ case 10:
+ case 13:
+ username[pos] = 0;
+ pos = -1;
+ break;
+ case 8:
+ case 127:
+ if (pos > 0) {
+ c_write_str("\b \b");
+ pos--;
+ }
+ break;
+ case 21:
+ case 27:
+ while (pos > 0) {
+ c_write_str("\b \b");
+ pos--;
+ }
+ break;
+ case 3:
+ case 4:
+ cleanup_exit(0);
+ break;
+ default:
+ if (((c >= ' ' && c <= '~') ||
+ ((unsigned char) c >= 160))
+ && pos < sizeof(username)-1) {
+ username[pos++] = c;
+ c_write(&c, 1);
+ }
+ break;
+ }
}
}
- c_write("\r\n", 2);
+ c_write_str("\r\n");
username[strcspn(username, "\n\r")] = '\0';
} else {
char stuff[200];
strncpy(username, cfg.username, 99);
username[99] = '\0';
- if (flags & FLAG_VERBOSE) {
+ if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
sprintf(stuff, "Using username \"%s\".\r\n", username);
- c_write(stuff, strlen(stuff));
+ c_write_str(stuff);
}
}
- if (!(flags & FLAG_WINDOWED)) {
- char prompt[200];
- sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost);
- if (!ssh_get_password(prompt, password, sizeof(password))) {
- /*
- * get_password failed to get a password (for
- * example because one was supplied on the command
- * line which has already failed to work).
- * Terminate.
- */
- logevent("No more passwords to try");
- ssh_state = SSH_STATE_CLOSED;
- crReturnV;
- }
- } else {
- c_write("password: ", 10);
-
- pos = 0;
- while (pos >= 0) {
- crWaitUntilV(!ispkt);
- while (inlen--) switch (c = *in++) {
- case 10: case 13:
- password[pos] = 0;
- pos = -1;
- break;
- case 8: case 127:
- if (pos > 0)
- pos--;
- break;
- case 21: case 27:
- pos = 0;
- break;
- case 3: case 4:
- random_save_seed();
- exit(0);
- break;
- default:
- if (((c >= ' ' && c <= '~') ||
- ((unsigned char)c >= 160)) && pos < 40)
- password[pos++] = c;
- break;
- }
- }
- c_write("\r\n", 2);
- }
+ /*
+ * Send an authentication request using method "none": (a)
+ * just in case it succeeds, and (b) so that we know what
+ * authentication methods we can usefully try next.
+ */
+ ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
+
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ ssh2_pkt_addstring(username);
+ ssh2_pkt_addstring("ssh-connection"); /* service requested */
+ ssh2_pkt_addstring("none"); /* method */
+ ssh2_pkt_send();
+ type = AUTH_TYPE_NONE;
+ gotit = FALSE;
+ we_are_in = FALSE;
+
+ tried_pubkey_config = FALSE;
+ tried_agent = FALSE;
+ tried_keyb_inter = FALSE;
+ kbd_inter_running = FALSE;
+ /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
+ if (*cfg.keyfile) {
+ publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
+ &publickey_bloblen);
+ } else
+ publickey_blob = NULL;
+
+ while (1) {
+ /*
+ * Wait for the result of the last authentication request.
+ */
+ if (!gotit)
+ crWaitUntilV(ispkt);
+ while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
+ char *banner;
+ int size;
+ /*
+ * Don't show the banner if we're operating in
+ * non-verbose non-interactive mode. (It's probably
+ * a script, which means nobody will read the
+ * banner _anyway_, and moreover the printing of
+ * the banner will screw up processing on the
+ * output of (say) plink.)
+ */
+ if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
+ ssh2_pkt_getstring(&banner, &size);
+ if (banner)
+ c_write_untrusted(banner, size);
+ }
+ crWaitUntilV(ispkt);
+ }
+ if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
+ logevent("Access granted");
+ we_are_in = TRUE;
+ break;
+ }
- ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(username);
- ssh2_pkt_addstring("ssh-connection"); /* service requested */
- ssh2_pkt_addstring("password");
- ssh2_pkt_addbool(FALSE);
- ssh2_pkt_addstring(password);
- ssh2_pkt_send();
+ if (kbd_inter_running &&
+ pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
+ /*
+ * This is a further prompt in keyboard-interactive
+ * authentication. Do nothing.
+ */
+ } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
+ bombout(("Strange packet received during authentication: type %d",
+ pktin.type));
+ crReturnV;
+ }
- crWaitUntilV(ispkt);
- if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
- c_write("Access denied\r\n", 15);
- logevent("Authentication refused");
- } else
- break;
- }
+ gotit = FALSE;
+
+ /*
+ * OK, we're now sitting on a USERAUTH_FAILURE message, so
+ * we can look at the string in it and know what we can
+ * helpfully try next.
+ */
+ if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
+ char *methods;
+ int methlen;
+ ssh2_pkt_getstring(&methods, &methlen);
+ kbd_inter_running = FALSE;
+ if (!ssh2_pkt_getbool()) {
+ /*
+ * We have received an unequivocal Access
+ * Denied. This can translate to a variety of
+ * messages:
+ *
+ * - if we'd just tried "none" authentication,
+ * it's not worth printing anything at all
+ *
+ * - if we'd just tried a public key _offer_,
+ * the message should be "Server refused our
+ * key" (or no message at all if the key
+ * came from Pageant)
+ *
+ * - if we'd just tried anything else, the
+ * message really should be "Access denied".
+ *
+ * Additionally, if we'd just tried password
+ * authentication, we should break out of this
+ * whole loop so as to go back to the username
+ * prompt.
+ */
+ if (type == AUTH_TYPE_NONE) {
+ /* do nothing */
+ } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
+ type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
+ if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
+ c_write_str("Server refused our key\r\n");
+ logevent("Server refused public key");
+ } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
+ /* server declined keyboard-interactive; ignore */
+ } else {
+ c_write_str("Access denied\r\n");
+ logevent("Access denied");
+ if (type == AUTH_TYPE_PASSWORD) {
+ we_are_in = FALSE;
+ break;
+ }
+ }
+ } else {
+ c_write_str("Further authentication required\r\n");
+ logevent("Further authentication required");
+ }
+
+ can_pubkey =
+ in_commasep_string("publickey", methods, methlen);
+ can_passwd =
+ in_commasep_string("password", methods, methlen);
+ can_keyb_inter = cfg.try_ki_auth &&
+ in_commasep_string("keyboard-interactive", methods, methlen);
+ }
+
+ method = 0;
+ ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
+
+ if (!method && can_pubkey && agent_exists() && !tried_agent) {
+ /*
+ * Attempt public-key authentication using Pageant.
+ */
+ static unsigned char request[5], *response, *p;
+ static int responselen;
+ static int i, nkeys;
+ static int authed = FALSE;
+ void *r;
+
+ ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
+
+ tried_agent = TRUE;
+
+ logevent("Pageant is running. Requesting keys.");
+
+ /* Request the keys held by the agent. */
+ PUT_32BIT(request, 1);
+ request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
+ agent_query(request, 5, &r, &responselen);
+ response = (unsigned char *) r;
+ if (response && responselen >= 5 &&
+ response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
+ p = response + 5;
+ nkeys = GET_32BIT(p);
+ p += 4;
+ {
+ char buf[64];
+ sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
+ logevent(buf);
+ }
+ for (i = 0; i < nkeys; i++) {
+ static char *pkblob, *alg, *commentp;
+ static int pklen, alglen, commentlen;
+ static int siglen, retlen, len;
+ static char *q, *agentreq, *ret;
+ void *vret;
+
+ {
+ char buf[64];
+ sprintf(buf, "Trying Pageant key #%d", i);
+ logevent(buf);
+ }
+ pklen = GET_32BIT(p);
+ p += 4;
+ if (publickey_blob &&
+ pklen == publickey_bloblen &&
+ !memcmp(p, publickey_blob, publickey_bloblen)) {
+ logevent("This key matches configured key file");
+ tried_pubkey_config = 1;
+ }
+ pkblob = p;
+ p += pklen;
+ alglen = GET_32BIT(pkblob);
+ alg = pkblob + 4;
+ commentlen = GET_32BIT(p);
+ p += 4;
+ commentp = p;
+ p += commentlen;
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ ssh2_pkt_addstring(username);
+ ssh2_pkt_addstring("ssh-connection"); /* service requested */
+ ssh2_pkt_addstring("publickey"); /* method */
+ ssh2_pkt_addbool(FALSE); /* no signature included */
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_addstring_data(alg, alglen);
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_addstring_data(pkblob, pklen);
+ ssh2_pkt_send();
+
+ crWaitUntilV(ispkt);
+ if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
+ logevent("Key refused");
+ continue;
+ }
+
+ if (flags & FLAG_VERBOSE) {
+ c_write_str
+ ("Authenticating with public key \"");
+ c_write(commentp, commentlen);
+ c_write_str("\" from agent\r\n");
+ }
+
+ /*
+ * Server is willing to accept the key.
+ * Construct a SIGN_REQUEST.
+ */
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ ssh2_pkt_addstring(username);
+ ssh2_pkt_addstring("ssh-connection"); /* service requested */
+ ssh2_pkt_addstring("publickey"); /* method */
+ ssh2_pkt_addbool(TRUE);
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_addstring_data(alg, alglen);
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_addstring_data(pkblob, pklen);
+
+ siglen = pktout.length - 5 + 4 + 20;
+ len = 1; /* message type */
+ len += 4 + pklen; /* key blob */
+ len += 4 + siglen; /* data to sign */
+ len += 4; /* flags */
+ agentreq = smalloc(4 + len);
+ PUT_32BIT(agentreq, len);
+ q = agentreq + 4;
+ *q++ = SSH2_AGENTC_SIGN_REQUEST;
+ PUT_32BIT(q, pklen);
+ q += 4;
+ memcpy(q, pkblob, pklen);
+ q += pklen;
+ PUT_32BIT(q, siglen);
+ q += 4;
+ /* Now the data to be signed... */
+ PUT_32BIT(q, 20);
+ q += 4;
+ memcpy(q, ssh2_session_id, 20);
+ q += 20;
+ memcpy(q, pktout.data + 5, pktout.length - 5);
+ q += pktout.length - 5;
+ /* And finally the (zero) flags word. */
+ PUT_32BIT(q, 0);
+ agent_query(agentreq, len + 4, &vret, &retlen);
+ ret = vret;
+ sfree(agentreq);
+ if (ret) {
+ if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
+ logevent("Sending Pageant's response");
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_addstring_data(ret + 9,
+ GET_32BIT(ret +
+ 5));
+ ssh2_pkt_send();
+ authed = TRUE;
+ break;
+ } else {
+ logevent
+ ("Pageant failed to answer challenge");
+ sfree(ret);
+ }
+ }
+ }
+ if (authed)
+ continue;
+ }
+ }
+
+ if (!method && can_pubkey && *cfg.keyfile
+ && !tried_pubkey_config) {
+ unsigned char *pub_blob;
+ char *algorithm, *comment;
+ int pub_blob_len;
+
+ tried_pubkey_config = TRUE;
+
+ ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
+
+ /*
+ * Try the public key supplied in the configuration.
+ *
+ * First, offer the public blob to see if the server is
+ * willing to accept it.
+ */
+ pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
+ &pub_blob_len);
+ if (pub_blob) {
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ ssh2_pkt_addstring(username);
+ ssh2_pkt_addstring("ssh-connection"); /* service requested */
+ ssh2_pkt_addstring("publickey"); /* method */
+ ssh2_pkt_addbool(FALSE); /* no signature included */
+ ssh2_pkt_addstring(algorithm);
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
+ ssh2_pkt_send();
+ logevent("Offered public key"); /* FIXME */
+
+ crWaitUntilV(ispkt);
+ if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
+ gotit = TRUE;
+ type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
+ continue; /* key refused; give up on it */
+ }
+
+ logevent("Offer of public key accepted");
+ /*
+ * Actually attempt a serious authentication using
+ * the key.
+ */
+ if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
+ sprintf(pwprompt,
+ "Passphrase for key \"%.100s\": ",
+ comment);
+ need_pw = TRUE;
+ } else {
+ need_pw = FALSE;
+ }
+ c_write_str("Authenticating with public key \"");
+ c_write_str(comment);
+ c_write_str("\"\r\n");
+ method = AUTH_PUBLICKEY_FILE;
+ }
+ }
+
+ if (!method && can_keyb_inter && !tried_keyb_inter) {
+ method = AUTH_KEYBOARD_INTERACTIVE;
+ type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
+ tried_keyb_inter = TRUE;
+
+ ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
+
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ ssh2_pkt_addstring(username);
+ ssh2_pkt_addstring("ssh-connection"); /* service requested */
+ ssh2_pkt_addstring("keyboard-interactive"); /* method */
+ ssh2_pkt_addstring(""); /* lang */
+ ssh2_pkt_addstring("");
+ ssh2_pkt_send();
+
+ crWaitUntilV(ispkt);
+ if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
+ if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
+ gotit = TRUE;
+ logevent("Keyboard-interactive authentication refused");
+ type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
+ continue;
+ }
+
+ kbd_inter_running = TRUE;
+ }
+
+ if (kbd_inter_running) {
+ method = AUTH_KEYBOARD_INTERACTIVE;
+ type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
+ tried_keyb_inter = TRUE;
+
+ ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
+
+ /* We've got packet with that "interactive" info
+ dump banners, and set its prompt as ours */
+ {
+ char *name, *inst, *lang, *prompt;
+ int name_len, inst_len, lang_len, prompt_len;
+ ssh2_pkt_getstring(&name, &name_len);
+ ssh2_pkt_getstring(&inst, &inst_len);
+ ssh2_pkt_getstring(&lang, &lang_len);
+ if (name_len > 0)
+ c_write_untrusted(name, name_len);
+ if (inst_len > 0)
+ c_write_untrusted(inst, inst_len);
+ num_prompts = ssh2_pkt_getuint32();
+
+ ssh2_pkt_getstring(&prompt, &prompt_len);
+ strncpy(pwprompt, prompt, sizeof(pwprompt));
+ pwprompt[prompt_len < sizeof(pwprompt) ?
+ prompt_len : sizeof(pwprompt)-1] = '\0';
+ need_pw = TRUE;
+
+ echo = ssh2_pkt_getbool();
+ }
+ }
+
+ if (!method && can_passwd) {
+ method = AUTH_PASSWORD;
+ ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
+ sprintf(pwprompt, "%.90s@%.90s's password: ", username,
+ savedhost);
+ need_pw = TRUE;
+ }
+
+ if (need_pw) {
+ if (ssh_get_line) {
+ if (!ssh_get_line(pwprompt, password,
+ sizeof(password), TRUE)) {
+ /*
+ * get_line failed to get a password (for
+ * example because one was supplied on the
+ * command line which has already failed to
+ * work). Terminate.
+ */
+ ssh2_pkt_init(SSH2_MSG_DISCONNECT);
+ ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
+ ssh2_pkt_addstring
+ ("No more passwords available to try");
+ ssh2_pkt_addstring("en"); /* language tag */
+ ssh2_pkt_send();
+ connection_fatal("Unable to authenticate");
+ ssh_state = SSH_STATE_CLOSED;
+ crReturnV;
+ }
+ } else {
+ static int pos = 0;
+ static char c;
+
+ c_write_untrusted(pwprompt, strlen(pwprompt));
+ ssh_send_ok = 1;
+
+ pos = 0;
+ while (pos >= 0) {
+ crWaitUntilV(!ispkt);
+ while (inlen--)
+ switch (c = *in++) {
+ case 10:
+ case 13:
+ password[pos] = 0;
+ pos = -1;
+ break;
+ case 8:
+ case 127:
+ if (pos > 0)
+ pos--;
+ break;
+ case 21:
+ case 27:
+ pos = 0;
+ break;
+ case 3:
+ case 4:
+ cleanup_exit(0);
+ break;
+ default:
+ if (pos < sizeof(password)-1)
+ password[pos++] = c;
+ break;
+ }
+ }
+ c_write_str("\r\n");
+ }
+ }
+
+ if (method == AUTH_PUBLICKEY_FILE) {
+ /*
+ * We have our passphrase. Now try the actual authentication.
+ */
+ struct ssh2_userkey *key;
+
+ key = ssh2_load_userkey(cfg.keyfile, password);
+ if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
+ if (key == SSH2_WRONG_PASSPHRASE) {
+ c_write_str("Wrong passphrase\r\n");
+ tried_pubkey_config = FALSE;
+ } else {
+ c_write_str("Unable to load private key\r\n");
+ tried_pubkey_config = TRUE;
+ }
+ /* Send a spurious AUTH_NONE to return to the top. */
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ ssh2_pkt_addstring(username);
+ ssh2_pkt_addstring("ssh-connection"); /* service requested */
+ ssh2_pkt_addstring("none"); /* method */
+ ssh2_pkt_send();
+ type = AUTH_TYPE_NONE;
+ } else {
+ unsigned char *blob, *sigdata;
+ int blob_len, sigdata_len;
+
+ /*
+ * We have loaded the private key and the server
+ * has announced that it's willing to accept it.
+ * Hallelujah. Generate a signature and send it.
+ */
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ ssh2_pkt_addstring(username);
+ ssh2_pkt_addstring("ssh-connection"); /* service requested */
+ ssh2_pkt_addstring("publickey"); /* method */
+ ssh2_pkt_addbool(TRUE);
+ ssh2_pkt_addstring(key->alg->name);
+ blob = key->alg->public_blob(key->data, &blob_len);
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_addstring_data(blob, blob_len);
+ sfree(blob);
+
+ /*
+ * The data to be signed is:
+ *
+ * string session-id
+ *
+ * followed by everything so far placed in the
+ * outgoing packet.
+ */
+ sigdata_len = pktout.length - 5 + 4 + 20;
+ sigdata = smalloc(sigdata_len);
+ PUT_32BIT(sigdata, 20);
+ memcpy(sigdata + 4, ssh2_session_id, 20);
+ memcpy(sigdata + 24, pktout.data + 5,
+ pktout.length - 5);
+ blob =
+ key->alg->sign(key->data, sigdata, sigdata_len,
+ &blob_len);
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_addstring_data(blob, blob_len);
+ sfree(blob);
+ sfree(sigdata);
+
+ ssh2_pkt_send();
+ type = AUTH_TYPE_PUBLICKEY;
+ }
+ } else if (method == AUTH_PASSWORD) {
+ /*
+ * We send the password packet lumped tightly together with
+ * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
+ * string long enough to make the total length of the two
+ * packets constant. This should ensure that a passive
+ * listener doing traffic analyis can't work out the length
+ * of the password.
+ *
+ * For this to work, we need an assumption about the
+ * maximum length of the password packet. I think 256 is
+ * pretty conservative. Anyone using a password longer than
+ * that probably doesn't have much to worry about from
+ * people who find out how long their password is!
+ */
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ ssh2_pkt_addstring(username);
+ ssh2_pkt_addstring("ssh-connection"); /* service requested */
+ ssh2_pkt_addstring("password");
+ ssh2_pkt_addbool(FALSE);
+ ssh2_pkt_addstring(password);
+ ssh2_pkt_defer();
+ /*
+ * We'll include a string that's an exact multiple of the
+ * cipher block size. If the cipher is NULL for some
+ * reason, we don't do this trick at all because we gain
+ * nothing by it.
+ */
+ if (cscipher) {
+ int stringlen, i;
+
+ stringlen = (256 - deferred_len);
+ stringlen += cscipher->blksize - 1;
+ stringlen -= (stringlen % cscipher->blksize);
+ if (cscomp) {
+ /*
+ * Temporarily disable actual compression,
+ * so we can guarantee to get this string
+ * exactly the length we want it. The
+ * compression-disabling routine should
+ * return an integer indicating how many
+ * bytes we should adjust our string length
+ * by.
+ */
+ stringlen -= cscomp->disable_compression();
+ }
+ ssh2_pkt_init(SSH2_MSG_IGNORE);
+ ssh2_pkt_addstring_start();
+ for (i = 0; i < stringlen; i++) {
+ char c = (char) random_byte();
+ ssh2_pkt_addstring_data(&c, 1);
+ }
+ ssh2_pkt_defer();
+ }
+ ssh_pkt_defersend();
+ logevent("Sent password");
+ type = AUTH_TYPE_PASSWORD;
+ } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
+ ssh2_pkt_adduint32(num_prompts);
+ ssh2_pkt_addstring(password);
+ memset(password, 0, sizeof(password));
+ ssh2_pkt_send();
+ type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
+ } else {
+ c_write_str
+ ("No supported authentication methods left to try!\r\n");
+ logevent
+ ("No supported authentications offered. Disconnecting");
+ ssh2_pkt_init(SSH2_MSG_DISCONNECT);
+ ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
+ ssh2_pkt_addstring
+ ("No supported authentication methods available");
+ ssh2_pkt_addstring("en"); /* language tag */
+ ssh2_pkt_send();
+ ssh_state = SSH_STATE_CLOSED;
+ crReturnV;
+ }
+ }
+ } while (!we_are_in);
/*
* Now we're authenticated for the connection protocol. The
/*
* So now create a channel with a session in it.
*/
+ ssh_channels = newtree234(ssh_channelcmp);
+ mainchan = smalloc(sizeof(struct ssh_channel));
+ mainchan->localid = alloc_channel_id();
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
ssh2_pkt_addstring("session");
- ssh2_pkt_adduint32(100); /* as good as any */
- ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big window which we ignore */
- ssh2_pkt_adduint32(0xFFFFFFFFUL); /* very big max pkt size */
+ ssh2_pkt_adduint32(mainchan->localid);
+ mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
+ ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
+ ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
ssh2_pkt_send();
crWaitUntilV(ispkt);
if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
- fatalbox("Server refused to open a session");
- /* FIXME: error data comes back in FAILURE packet */
+ bombout(("Server refused to open a session"));
+ crReturnV;
+ /* FIXME: error data comes back in FAILURE packet */
}
- if (ssh2_pkt_getuint32() != 100) {
- fatalbox("Server's channel confirmation cited wrong channel");
+ if (ssh2_pkt_getuint32() != mainchan->localid) {
+ bombout(("Server's channel confirmation cited wrong channel"));
+ crReturnV;
}
- ssh_remote_channel = ssh2_pkt_getuint32();
- remote_winsize = ssh2_pkt_getuint32();
- remote_maxpkt = ssh2_pkt_getuint32();
+ mainchan->remoteid = ssh2_pkt_getuint32();
+ mainchan->type = CHAN_MAINSESSION;
+ mainchan->closes = 0;
+ mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
+ mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
+ bufchain_init(&mainchan->v.v2.outbuffer);
+ add234(ssh_channels, mainchan);
logevent("Opened channel for session");
/*
- * Now allocate a pty for the session.
+ * Potentially enable X11 forwarding.
*/
- ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */
- ssh2_pkt_addstring("pty-req");
- ssh2_pkt_addbool(1); /* want reply */
- ssh2_pkt_addstring(cfg.termtype);
- ssh2_pkt_adduint32(cols);
- ssh2_pkt_adduint32(rows);
- ssh2_pkt_adduint32(0); /* pixel width */
- ssh2_pkt_adduint32(0); /* pixel height */
- ssh2_pkt_addstring_start();
- ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
- ssh2_pkt_send();
+ if (cfg.x11_forward) {
+ char proto[20], data[64];
+ logevent("Requesting X11 forwarding");
+ x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
+ ssh2_pkt_adduint32(mainchan->remoteid);
+ ssh2_pkt_addstring("x11-req");
+ ssh2_pkt_addbool(1); /* want reply */
+ ssh2_pkt_addbool(0); /* many connections */
+ ssh2_pkt_addstring(proto);
+ ssh2_pkt_addstring(data);
+ ssh2_pkt_adduint32(0); /* screen number */
+ ssh2_pkt_send();
+
+ do {
+ crWaitUntilV(ispkt);
+ if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
+ }
+ } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
- do { /* FIXME: pay attention to these */
- crWaitUntilV(ispkt);
- } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
+ if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
+ bombout(("Unexpected response to X11 forwarding request:"
+ " packet type %d", pktin.type));
+ crReturnV;
+ }
+ logevent("X11 forwarding refused");
+ } else {
+ logevent("X11 forwarding enabled");
+ ssh_X11_fwd_enabled = TRUE;
+ }
+ }
- if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
- if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
- fatalbox("Server got confused by pty request");
- }
- c_write("Server refused to allocate pty\r\n", 32);
- } else {
- logevent("Allocated pty");
+ /*
+ * Enable port forwardings.
+ */
+ {
+ static char *e; /* preserve across crReturn */
+ char type;
+ int n;
+ int sport,dport;
+ char sports[256], dports[256], host[256];
+ char buf[1024];
+
+ ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
+ /* Add port forwardings. */
+ e = cfg.portfwd;
+ while (*e) {
+ type = *e++;
+ n = 0;
+ while (*e && *e != '\t')
+ sports[n++] = *e++;
+ sports[n] = 0;
+ if (*e == '\t')
+ e++;
+ n = 0;
+ while (*e && *e != ':')
+ host[n++] = *e++;
+ host[n] = 0;
+ if (*e == ':')
+ e++;
+ n = 0;
+ while (*e)
+ dports[n++] = *e++;
+ dports[n] = 0;
+ e++;
+ dport = atoi(dports);
+ sport = atoi(sports);
+ if (sport && dport) {
+ if (type == 'L') {
+ pfd_addforward(host, dport, sport);
+ sprintf(buf, "Local port %d forwarding to %s:%d",
+ sport, host, dport);
+ logevent(buf);
+ } else {
+ struct ssh_rportfwd *pf;
+ pf = smalloc(sizeof(*pf));
+ strcpy(pf->dhost, host);
+ pf->dport = dport;
+ pf->sport = sport;
+ if (add234(ssh_rportfwds, pf) != pf) {
+ sprintf(buf,
+ "Duplicate remote port forwarding to %s:%d",
+ host, dport);
+ logevent(buf);
+ sfree(pf);
+ } else {
+ sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
+ sport, host, dport);
+ logevent(buf);
+ ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
+ ssh2_pkt_addstring("tcpip-forward");
+ ssh2_pkt_addbool(1);/* want reply */
+ if (cfg.rport_acceptall)
+ ssh2_pkt_addstring("0.0.0.0");
+ else
+ ssh2_pkt_addstring("127.0.0.1");
+ ssh2_pkt_adduint32(sport);
+ ssh2_pkt_send();
+
+ do {
+ crWaitUntilV(ispkt);
+ if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue;/* nonexistent channel */
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
+ }
+ } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+
+ if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
+ if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
+ bombout(("Unexpected response to port "
+ "forwarding request: packet type %d",
+ pktin.type));
+ crReturnV;
+ }
+ logevent("Server refused this port forwarding");
+ } else {
+ logevent("Remote port forwarding enabled");
+ }
+ }
+ }
+ }
+ }
}
/*
- * Start a shell.
+ * Potentially enable agent forwarding.
*/
- ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(ssh_remote_channel); /* recipient channel */
- ssh2_pkt_addstring("shell");
- ssh2_pkt_addbool(1); /* want reply */
- ssh2_pkt_send();
- do { /* FIXME: pay attention to these */
- crWaitUntilV(ispkt);
- } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
- if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
- if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
- fatalbox("Server got confused by shell request");
- }
- fatalbox("Server refused to start a shell");
+ if (cfg.agentfwd && agent_exists()) {
+ logevent("Requesting OpenSSH-style agent forwarding");
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
+ ssh2_pkt_adduint32(mainchan->remoteid);
+ ssh2_pkt_addstring("auth-agent-req@openssh.com");
+ ssh2_pkt_addbool(1); /* want reply */
+ ssh2_pkt_send();
+
+ do {
+ crWaitUntilV(ispkt);
+ if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
+ }
+ } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+
+ if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
+ if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
+ bombout(("Unexpected response to agent forwarding request:"
+ " packet type %d", pktin.type));
+ crReturnV;
+ }
+ logevent("Agent forwarding refused");
+ } else {
+ logevent("Agent forwarding enabled");
+ ssh_agentfwd_enabled = TRUE;
+ }
+ }
+
+ /*
+ * Now allocate a pty for the session.
+ */
+ if (!cfg.nopty) {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
+ ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
+ ssh2_pkt_addstring("pty-req");
+ ssh2_pkt_addbool(1); /* want reply */
+ ssh2_pkt_addstring(cfg.termtype);
+ ssh2_pkt_adduint32(cols);
+ ssh2_pkt_adduint32(rows);
+ ssh2_pkt_adduint32(0); /* pixel width */
+ ssh2_pkt_adduint32(0); /* pixel height */
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
+ ssh2_pkt_send();
+ ssh_state = SSH_STATE_INTERMED;
+
+ do {
+ crWaitUntilV(ispkt);
+ if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
+ }
+ } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+
+ if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
+ if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
+ bombout(("Unexpected response to pty request:"
+ " packet type %d", pktin.type));
+ crReturnV;
+ }
+ c_write_str("Server refused to allocate pty\r\n");
+ ssh_editing = ssh_echoing = 1;
+ } else {
+ logevent("Allocated pty");
+ }
} else {
- logevent("Started a shell");
+ ssh_editing = ssh_echoing = 1;
+ }
+
+ /*
+ * Start a shell or a remote command. We may have to attempt
+ * this twice if the config data has provided a second choice
+ * of command.
+ */
+ while (1) {
+ int subsys;
+ char *cmd;
+
+ if (ssh_fallback_cmd) {
+ subsys = cfg.ssh_subsys2;
+ cmd = cfg.remote_cmd_ptr2;
+ } else {
+ subsys = cfg.ssh_subsys;
+ cmd = cfg.remote_cmd_ptr;
+ }
+
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
+ ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
+ if (subsys) {
+ ssh2_pkt_addstring("subsystem");
+ ssh2_pkt_addbool(1); /* want reply */
+ ssh2_pkt_addstring(cmd);
+ } else if (*cmd) {
+ ssh2_pkt_addstring("exec");
+ ssh2_pkt_addbool(1); /* want reply */
+ ssh2_pkt_addstring(cmd);
+ } else {
+ ssh2_pkt_addstring("shell");
+ ssh2_pkt_addbool(1); /* want reply */
+ }
+ ssh2_pkt_send();
+ do {
+ crWaitUntilV(ispkt);
+ if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
+ }
+ } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
+ if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
+ bombout(("Unexpected response to shell/command request:"
+ " packet type %d", pktin.type));
+ crReturnV;
+ }
+ /*
+ * We failed to start the command. If this is the
+ * fallback command, we really are finished; if it's
+ * not, and if the fallback command exists, try falling
+ * back to it before complaining.
+ */
+ if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
+ logevent("Primary command failed; attempting fallback");
+ ssh_fallback_cmd = TRUE;
+ continue;
+ }
+ bombout(("Server refused to start a shell/command"));
+ crReturnV;
+ } else {
+ logevent("Started a shell/command");
+ }
+ break;
}
+ ssh_state = SSH_STATE_SESSION;
+ if (size_needed)
+ ssh_size();
+ if (eof_needed)
+ ssh_special(TS_EOF);
+
/*
* Transfer data!
*/
+ ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
ssh_send_ok = 1;
while (1) {
+ static int try_send;
crReturnV;
+ try_send = FALSE;
if (ispkt) {
if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
- pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
- char *data;
- int length;
- if (ssh2_pkt_getuint32() != 100)
- continue; /* wrong channel */
- if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
- ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
- continue; /* extended but not stderr */
- ssh2_pkt_getstring(&data, &length);
- if (data)
- c_write(data, length);
+ pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
+ char *data;
+ int length;
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
+ ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
+ continue; /* extended but not stderr */
+ ssh2_pkt_getstring(&data, &length);
+ if (data) {
+ int bufsize;
+ c->v.v2.locwindow -= length;
+ switch (c->type) {
+ case CHAN_MAINSESSION:
+ bufsize =
+ from_backend(pktin.type ==
+ SSH2_MSG_CHANNEL_EXTENDED_DATA,
+ data, length);
+ break;
+ case CHAN_X11:
+ bufsize = x11_send(c->u.x11.s, data, length);
+ break;
+ case CHAN_SOCKDATA:
+ bufsize = pfd_send(c->u.pfd.s, data, length);
+ break;
+ case CHAN_AGENT:
+ while (length > 0) {
+ if (c->u.a.lensofar < 4) {
+ int l = min(4 - c->u.a.lensofar, length);
+ memcpy(c->u.a.msglen + c->u.a.lensofar,
+ data, l);
+ data += l;
+ length -= l;
+ c->u.a.lensofar += l;
+ }
+ if (c->u.a.lensofar == 4) {
+ c->u.a.totallen =
+ 4 + GET_32BIT(c->u.a.msglen);
+ c->u.a.message = smalloc(c->u.a.totallen);
+ memcpy(c->u.a.message, c->u.a.msglen, 4);
+ }
+ if (c->u.a.lensofar >= 4 && length > 0) {
+ int l =
+ min(c->u.a.totallen - c->u.a.lensofar,
+ length);
+ memcpy(c->u.a.message + c->u.a.lensofar,
+ data, l);
+ data += l;
+ length -= l;
+ c->u.a.lensofar += l;
+ }
+ if (c->u.a.lensofar == c->u.a.totallen) {
+ void *reply, *sentreply;
+ int replylen;
+ agent_query(c->u.a.message,
+ c->u.a.totallen, &reply,
+ &replylen);
+ if (reply)
+ sentreply = reply;
+ else {
+ /* Fake SSH_AGENT_FAILURE. */
+ sentreply = "\0\0\0\1\5";
+ replylen = 5;
+ }
+ ssh2_add_channel_data(c, sentreply,
+ replylen);
+ try_send = TRUE;
+ if (reply)
+ sfree(reply);
+ sfree(c->u.a.message);
+ c->u.a.lensofar = 0;
+ }
+ }
+ bufsize = 0;
+ break;
+ }
+ /*
+ * If we are not buffering too much data,
+ * enlarge the window again at the remote side.
+ */
+ if (bufsize < OUR_V2_WINSIZE)
+ ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
+ }
} else if (pktin.type == SSH2_MSG_DISCONNECT) {
- ssh_state = SSH_STATE_CLOSED;
- logevent("Received disconnect request");
- } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
- continue; /* exit status et al; ignore (FIXME?) */
+ ssh_state = SSH_STATE_CLOSED;
+ logevent("Received disconnect message");
+ crReturnV;
+ } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+
+ if (c->type == CHAN_X11) {
+ /*
+ * Remote EOF on an X11 channel means we should
+ * wrap up and close the channel ourselves.
+ */
+ x11_close(c->u.x11.s);
+ sshfwd_close(c);
+ } else if (c->type == CHAN_AGENT) {
+ sshfwd_close(c);
+ } else if (c->type == CHAN_SOCKDATA) {
+ pfd_close(c->u.pfd.s);
+ sshfwd_close(c);
+ }
+ } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ /* Do pre-close processing on the channel. */
+ switch (c->type) {
+ case CHAN_MAINSESSION:
+ break; /* nothing to see here, move along */
+ case CHAN_X11:
+ if (c->u.x11.s != NULL)
+ x11_close(c->u.x11.s);
+ sshfwd_close(c);
+ break;
+ case CHAN_AGENT:
+ sshfwd_close(c);
+ break;
+ case CHAN_SOCKDATA:
+ if (c->u.pfd.s != NULL)
+ pfd_close(c->u.pfd.s);
+ sshfwd_close(c);
+ break;
+ }
+ if (c->closes == 0) {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_send();
+ }
+ del234(ssh_channels, c);
+ bufchain_clear(&c->v.v2.outbuffer);
+ sfree(c);
+
+ /*
+ * See if that was the last channel left open.
+ */
+ if (count234(ssh_channels) == 0) {
+#if 0
+ /*
+ * We used to send SSH_MSG_DISCONNECT here,
+ * because I'd believed that _every_ conforming
+ * SSH2 connection had to end with a disconnect
+ * being sent by at least one side; apparently
+ * I was wrong and it's perfectly OK to
+ * unceremoniously slam the connection shut
+ * when you're done, and indeed OpenSSH feels
+ * this is more polite than sending a
+ * DISCONNECT. So now we don't.
+ */
+ logevent("All channels closed. Disconnecting");
+ ssh2_pkt_init(SSH2_MSG_DISCONNECT);
+ ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
+ ssh2_pkt_addstring("All open channels closed");
+ ssh2_pkt_addstring("en"); /* language tag */
+ ssh2_pkt_send();
+#endif
+ ssh_state = SSH_STATE_CLOSED;
+ crReturnV;
+ }
+ continue; /* remote sends close; ignore (FIXME) */
} else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
- continue; /* ignore for now (FIXME!) */
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
+ try_send = TRUE;
+ } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ if (c->type != CHAN_SOCKDATA_DORMANT)
+ continue; /* dunno why they're confirming this */
+ c->remoteid = ssh2_pkt_getuint32();
+ c->type = CHAN_SOCKDATA;
+ c->v.v2.remwindow = ssh2_pkt_getuint32();
+ c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
+ bufchain_init(&c->v.v2.outbuffer);
+ if (c->u.pfd.s)
+ pfd_confirm(c->u.pfd.s);
+ if (c->closes) {
+ /*
+ * We have a pending close on this channel,
+ * which we decided on before the server acked
+ * the channel open. So now we know the
+ * remoteid, we can close it again.
+ */
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_send();
+ }
+ } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ if (c->type != CHAN_SOCKDATA_DORMANT)
+ continue; /* dunno why they're failing this */
+
+ logevent("Forwarded connection refused by server");
+
+ pfd_close(c->u.pfd.s);
+
+ del234(ssh_channels, c);
+ sfree(c);
+ } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
+ unsigned localid;
+ char *type;
+ int typelen, want_reply;
+ struct ssh_channel *c;
+
+ localid = ssh2_pkt_getuint32();
+ ssh2_pkt_getstring(&type, &typelen);
+ want_reply = ssh2_pkt_getbool();
+
+ /*
+ * First, check that the channel exists. Otherwise,
+ * we can instantly disconnect with a rude message.
+ */
+ c = find234(ssh_channels, &localid, ssh_channelfind);
+ if (!c) {
+ char buf[80];
+ sprintf(buf, "Received channel request for nonexistent"
+ " channel %d", localid);
+ logevent(buf);
+ ssh2_pkt_init(SSH2_MSG_DISCONNECT);
+ ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
+ ssh2_pkt_addstring(buf);
+ ssh2_pkt_addstring("en"); /* language tag */
+ ssh2_pkt_send();
+ connection_fatal(buf);
+ ssh_state = SSH_STATE_CLOSED;
+ crReturnV;
+ }
+
+ /*
+ * Having got the channel number, we now look at
+ * the request type string to see if it's something
+ * we recognise.
+ */
+ if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
+ c == mainchan) {
+ /* We recognise "exit-status" on the primary channel. */
+ char buf[100];
+ ssh_exitcode = ssh2_pkt_getuint32();
+ sprintf(buf, "Server sent command exit status %d",
+ ssh_exitcode);
+ logevent(buf);
+ if (want_reply) {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_send();
+ }
+ } else {
+ /*
+ * This is a channel request we don't know
+ * about, so we now either ignore the request
+ * or respond with CHANNEL_FAILURE, depending
+ * on want_reply.
+ */
+ if (want_reply) {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_send();
+ }
+ }
+ } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
+ char *type;
+ int typelen, want_reply;
+
+ ssh2_pkt_getstring(&type, &typelen);
+ want_reply = ssh2_pkt_getbool();
+
+ /*
+ * We currently don't support any global requests
+ * at all, so we either ignore the request or
+ * respond with REQUEST_FAILURE, depending on
+ * want_reply.
+ */
+ if (want_reply) {
+ ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
+ ssh2_pkt_send();
+ }
+ } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
+ char *type;
+ int typelen;
+ char *error = NULL;
+ struct ssh_channel *c;
+ unsigned remid, winsize, pktsize;
+ ssh2_pkt_getstring(&type, &typelen);
+ c = smalloc(sizeof(struct ssh_channel));
+
+ remid = ssh2_pkt_getuint32();
+ winsize = ssh2_pkt_getuint32();
+ pktsize = ssh2_pkt_getuint32();
+
+ if (typelen == 3 && !memcmp(type, "x11", 3)) {
+ if (!ssh_X11_fwd_enabled)
+ error = "X11 forwarding is not enabled";
+ else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
+ NULL) {
+ error = "Unable to open an X11 connection";
+ } else {
+ c->type = CHAN_X11;
+ }
+ } else if (typelen == 15 &&
+ !memcmp(type, "forwarded-tcpip", 15)) {
+ struct ssh_rportfwd pf, *realpf;
+ char *dummy;
+ int dummylen;
+ ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
+ pf.sport = ssh2_pkt_getuint32();
+ realpf = find234(ssh_rportfwds, &pf, NULL);
+ if (realpf == NULL) {
+ error = "Remote port is not recognised";
+ } else {
+ char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
+ realpf->dport, c);
+ char buf[1024];
+ sprintf(buf, "Received remote port open request for %s:%d",
+ realpf->dhost, realpf->dport);
+ logevent(buf);
+ if (e != NULL) {
+ sprintf(buf, "Port open failed: %s", e);
+ logevent(buf);
+ error = "Port open failed";
+ } else {
+ logevent("Forwarded port opened successfully");
+ c->type = CHAN_SOCKDATA;
+ }
+ }
+ } else if (typelen == 22 &&
+ !memcmp(type, "auth-agent@openssh.com", 3)) {
+ if (!ssh_agentfwd_enabled)
+ error = "Agent forwarding is not enabled";
+ else {
+ c->type = CHAN_AGENT; /* identify channel type */
+ c->u.a.lensofar = 0;
+ }
+ } else {
+ error = "Unsupported channel type requested";
+ }
+
+ c->remoteid = remid;
+ if (error) {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
+ ssh2_pkt_addstring(error);
+ ssh2_pkt_addstring("en"); /* language tag */
+ ssh2_pkt_send();
+ sfree(c);
+ } else {
+ c->localid = alloc_channel_id();
+ c->closes = 0;
+ c->v.v2.locwindow = OUR_V2_WINSIZE;
+ c->v.v2.remwindow = winsize;
+ c->v.v2.remmaxpkt = pktsize;
+ bufchain_init(&c->v.v2.outbuffer);
+ add234(ssh_channels, c);
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_adduint32(c->localid);
+ ssh2_pkt_adduint32(c->v.v2.locwindow);
+ ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
+ ssh2_pkt_send();
+ }
} else {
- fatalbox("Strange packet received: type %d", pktin.type);
+ bombout(("Strange packet received: type %d", pktin.type));
+ crReturnV;
}
} else {
- /* FIXME: for now, ignore window size */
- ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
- ssh2_pkt_adduint32(ssh_remote_channel);
- ssh2_pkt_addstring_start();
- ssh2_pkt_addstring_data(in, inlen);
- ssh2_pkt_send();
+ /*
+ * We have spare data. Add it to the channel buffer.
+ */
+ ssh2_add_channel_data(mainchan, in, inlen);
+ try_send = TRUE;
+ }
+ if (try_send) {
+ int i;
+ struct ssh_channel *c;
+ /*
+ * Try to send data on all channels if we can.
+ */
+ for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
+ int bufsize = ssh2_try_send(c);
+ if (bufsize == 0) {
+ switch (c->type) {
+ case CHAN_MAINSESSION:
+ /* stdin need not receive an unthrottle
+ * notification since it will be polled */
+ break;
+ case CHAN_X11:
+ x11_unthrottle(c->u.x11.s);
+ break;
+ case CHAN_AGENT:
+ /* agent sockets are request/response and need no
+ * buffer management */
+ break;
+ case CHAN_SOCKDATA:
+ pfd_unthrottle(c->u.pfd.s);
+ break;
+ }
+ }
+ }
}
}
static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
{
if (do_ssh2_transport(in, inlen, ispkt) == 0)
- return;
+ return;
do_ssh2_authconn(in, inlen, ispkt);
}
/*
- * Called to set up the connection. Will arrange for WM_NETEVENT
- * messages to be passed to the specified window, whose window
- * procedure should then call telnet_msg().
+ * Called to set up the connection.
*
* Returns an error message, or NULL on success.
*/
-static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
+static char *ssh_init(char *host, int port, char **realhost, int nodelay)
+{
char *p;
-
+
#ifdef MSCRYPTOAPI
- if(crypto_startup() == 0)
+ if (crypto_startup() == 0)
return "Microsoft high encryption pack not installed!";
#endif
- p = connect_to_host(host, port, realhost);
+ ssh_send_ok = 0;
+ ssh_editing = 0;
+ ssh_echoing = 0;
+ ssh1_throttle_count = 0;
+ ssh_overall_bufsize = 0;
+ ssh_fallback_cmd = 0;
+
+ p = connect_to_host(host, port, realhost, nodelay);
if (p != NULL)
return p;
- if (!do_ssh_init())
- return "Protocol initialisation error";
-
- if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
- switch (WSAGetLastError()) {
- case WSAENETDOWN: return "Network is down";
- default: return "WSAAsyncSelect(): unknown error";
- }
-
return NULL;
}
/*
- * Process a WM_NETEVENT message. Will return 0 if the connection
- * has closed, or <0 for a socket error.
+ * Called to send data down the Telnet connection.
*/
-static int ssh_msg (WPARAM wParam, LPARAM lParam) {
- int ret;
- char buf[256];
-
- /*
- * Because reading less than the whole of the available pending
- * data can generate an FD_READ event, we need to allow for the
- * possibility that FD_READ may arrive with FD_CLOSE already in
- * the queue; so it's possible that we can get here even with s
- * invalid. If so, we return 1 and don't worry about it.
- */
- if (s == INVALID_SOCKET)
- return 1;
+static int ssh_send(char *buf, int len)
+{
+ if (s == NULL || ssh_protocol == NULL)
+ return 0;
- if (WSAGETSELECTERROR(lParam) != 0)
- return -WSAGETSELECTERROR(lParam);
+ ssh_protocol(buf, len, 0);
- switch (WSAGETSELECTEVENT(lParam)) {
- case FD_READ:
- case FD_CLOSE:
- ret = recv(s, buf, sizeof(buf), 0);
- if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
- return 1;
- if (ret < 0) /* any _other_ error */
- return -10000-WSAGetLastError();
- if (ret == 0) {
- s = INVALID_SOCKET;
- return 0;
- }
- ssh_gotdata (buf, ret);
- if (ssh_state == SSH_STATE_CLOSED) {
- closesocket(s);
- s = INVALID_SOCKET;
- return 0;
- }
- return 1;
- }
- return 1; /* shouldn't happen, but WTF */
+ return ssh_sendbuffer();
}
/*
- * Called to send data down the Telnet connection.
+ * Called to query the current amount of buffered stdin data.
*/
-static void ssh_send (char *buf, int len) {
- if (s == INVALID_SOCKET)
- return;
+static int ssh_sendbuffer(void)
+{
+ int override_value;
- ssh_protocol(buf, len, 0);
+ if (s == NULL || ssh_protocol == NULL)
+ return 0;
+
+ /*
+ * If the SSH socket itself has backed up, add the total backup
+ * size on that to any individual buffer on the stdin channel.
+ */
+ override_value = 0;
+ if (ssh_throttled_all)
+ override_value = ssh_overall_bufsize;
+
+ if (ssh_version == 1) {
+ return override_value;
+ } else if (ssh_version == 2) {
+ if (!mainchan || mainchan->closes > 0)
+ return override_value;
+ else
+ return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
+ }
+
+ return 0;
}
/*
- * Called to set the size of the window from Telnet's POV.
+ * Called to set the size of the window from SSH's POV.
*/
-static void ssh_size(void) {
+static void ssh_size(void)
+{
switch (ssh_state) {
case SSH_STATE_BEFORE_SIZE:
+ case SSH_STATE_PREPACKET:
case SSH_STATE_CLOSED:
break; /* do nothing */
case SSH_STATE_INTERMED:
size_needed = TRUE; /* buffer for later */
break;
case SSH_STATE_SESSION:
- if (!cfg.nopty) {
- send_packet(SSH1_CMSG_WINDOW_SIZE,
- PKT_INT, rows, PKT_INT, cols,
- PKT_INT, 0, PKT_INT, 0, PKT_END);
- }
+ if (!cfg.nopty) {
+ if (ssh_version == 1) {
+ send_packet(SSH1_CMSG_WINDOW_SIZE,
+ PKT_INT, rows, PKT_INT, cols,
+ PKT_INT, 0, PKT_INT, 0, PKT_END);
+ } else {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
+ ssh2_pkt_adduint32(mainchan->remoteid);
+ ssh2_pkt_addstring("window-change");
+ ssh2_pkt_addbool(0);
+ ssh2_pkt_adduint32(cols);
+ ssh2_pkt_adduint32(rows);
+ ssh2_pkt_adduint32(0);
+ ssh2_pkt_adduint32(0);
+ ssh2_pkt_send();
+ }
+ }
+ break;
}
}
* can send an EOF and collect resulting output (e.g. `plink
* hostname sort').
*/
-static void ssh_special (Telnet_Special code) {
+static void ssh_special(Telnet_Special code)
+{
if (code == TS_EOF) {
- if (ssh_version = 1) {
- send_packet(SSH1_CMSG_EOF, PKT_END);
- } else {
- ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
- ssh2_pkt_adduint32(ssh_remote_channel);
- ssh2_pkt_send();
- }
+ if (ssh_state != SSH_STATE_SESSION) {
+ /*
+ * Buffer the EOF in case we are pre-SESSION, so we can
+ * send it as soon as we reach SESSION.
+ */
+ if (code == TS_EOF)
+ eof_needed = TRUE;
+ return;
+ }
+ if (ssh_version == 1) {
+ send_packet(SSH1_CMSG_EOF, PKT_END);
+ } else {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
+ ssh2_pkt_adduint32(mainchan->remoteid);
+ ssh2_pkt_send();
+ }
+ logevent("Sent EOF message");
+ } else if (code == TS_PING) {
+ if (ssh_state == SSH_STATE_CLOSED
+ || ssh_state == SSH_STATE_PREPACKET) return;
+ if (ssh_version == 1) {
+ send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
+ } else {
+ ssh2_pkt_init(SSH2_MSG_IGNORE);
+ ssh2_pkt_addstring_start();
+ ssh2_pkt_send();
+ }
} else {
- /* do nothing */
+ /* do nothing */
}
}
+void *new_sock_channel(Socket s)
+{
+ struct ssh_channel *c;
+ c = smalloc(sizeof(struct ssh_channel));
+
+ if (c) {
+ c->remoteid = -1; /* to be set when open confirmed */
+ c->localid = alloc_channel_id();
+ c->closes = 0;
+ c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
+ c->u.pfd.s = s;
+ add234(ssh_channels, c);
+ }
+ return c;
+}
/*
- * Read and decrypt one incoming SSH packet.
- * (only used by pSCP)
+ * This is called when stdout/stderr (the entity to which
+ * from_backend sends data) manages to clear some backlog.
*/
-static void get_packet(void)
+void ssh_unthrottle(int bufsize)
{
- unsigned char buf[4096], *p;
- long to_read;
- int len;
-
- p = NULL;
- len = 0;
-
- while ((to_read = s_rdpkt(&p, &len)) > 0) {
- if (to_read > sizeof(buf)) to_read = sizeof(buf);
- len = s_read(buf, to_read);
- if (len != to_read) {
- closesocket(s);
- s = INVALID_SOCKET;
- return;
+ if (ssh_version == 1) {
+ if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
+ ssh1_stdout_throttling = 0;
+ ssh1_throttle(-1);
}
- p = buf;
+ } else {
+ if (mainchan && mainchan->closes == 0)
+ ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
}
-
- assert(len == 0);
}
-/*
- * Receive a block of data over the SSH link. Block until
- * all data is available. Return nr of bytes read (0 if lost connection).
- * (only used by pSCP)
- */
-int ssh_scp_recv(unsigned char *buf, int len)
+void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
{
- static int pending_input_len = 0;
- static unsigned char *pending_input_ptr;
- int to_read = len;
+ struct ssh_channel *c = (struct ssh_channel *)channel;
+ char buf[1024];
- if (pending_input_len >= to_read) {
- memcpy(buf, pending_input_ptr, to_read);
- pending_input_ptr += to_read;
- pending_input_len -= to_read;
- return len;
- }
-
- if (pending_input_len > 0) {
- memcpy(buf, pending_input_ptr, pending_input_len);
- buf += pending_input_len;
- to_read -= pending_input_len;
- pending_input_len = 0;
- }
+ sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
+ logevent(buf);
- if (s == INVALID_SOCKET)
- return 0;
- while (to_read > 0) {
- get_packet();
- if (s == INVALID_SOCKET)
- return 0;
- if (pktin.type == SSH1_SMSG_STDOUT_DATA) {
- int plen = GET_32BIT(pktin.body);
- if (plen <= to_read) {
- memcpy(buf, pktin.body + 4, plen);
- buf += plen;
- to_read -= plen;
- } else {
- memcpy(buf, pktin.body + 4, to_read);
- pending_input_len = plen - to_read;
- pending_input_ptr = pktin.body + 4 + to_read;
- to_read = 0;
- }
- } else if (pktin.type == SSH1_SMSG_STDERR_DATA) {
- int plen = GET_32BIT(pktin.body);
- fwrite(pktin.body + 4, plen, 1, stderr);
- } else if (pktin.type == SSH1_MSG_DISCONNECT) {
- logevent("Received disconnect request");
- } else if (pktin.type == SSH1_SMSG_SUCCESS ||
- pktin.type == SSH1_SMSG_FAILURE) {
- /* ignore */
- } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
- char logbuf[100];
- sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body));
- logevent(logbuf);
- send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
- logevent("Closing connection");
- closesocket(s);
- s = INVALID_SOCKET;
- } else {
- fatalbox("Strange packet received: type %d", pktin.type);
- }
+ if (ssh_version == 1) {
+ send_packet(SSH1_MSG_PORT_OPEN,
+ PKT_INT, c->localid,
+ PKT_STR, hostname,
+ PKT_INT, port,
+ //PKT_STR, <org:orgport>,
+ PKT_END);
+ } else {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
+ ssh2_pkt_addstring("direct-tcpip");
+ ssh2_pkt_adduint32(c->localid);
+ c->v.v2.locwindow = OUR_V2_WINSIZE;
+ ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
+ ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
+ ssh2_pkt_addstring(hostname);
+ ssh2_pkt_adduint32(port);
+ /*
+ * We make up values for the originator data; partly it's
+ * too much hassle to keep track, and partly I'm not
+ * convinced the server should be told details like that
+ * about my local network configuration.
+ */
+ ssh2_pkt_addstring("client-side-connection");
+ ssh2_pkt_adduint32(0);
+ ssh2_pkt_send();
}
-
- return len;
}
-/*
- * Send a block of data over the SSH link.
- * Block until all data is sent.
- * (only used by pSCP)
- */
-void ssh_scp_send(unsigned char *buf, int len)
+
+static Socket ssh_socket(void)
{
- if (s == INVALID_SOCKET)
- return;
- send_packet(SSH1_CMSG_STDIN_DATA,
- PKT_INT, len, PKT_DATA, buf, len, PKT_END);
+ return s;
}
-/*
- * Send an EOF notification to the server.
- * (only used by pSCP)
- */
-void ssh_scp_send_eof(void)
+static int ssh_sendok(void)
{
- if (s == INVALID_SOCKET)
- return;
- send_packet(SSH1_CMSG_EOF, PKT_END);
+ return ssh_send_ok;
}
-/*
- * Set up the connection, login on the remote host and
- * start execution of a command.
- * Returns an error message, or NULL on success.
- * (only used by pSCP)
- */
-char *ssh_scp_init(char *host, int port, char *cmd, char **realhost)
+static int ssh_ldisc(int option)
{
- char buf[160], *p;
-
-#ifdef MSCRYPTOAPI
- if (crypto_startup() == 0)
- return "Microsoft high encryption pack not installed!";
-#endif
-
- p = connect_to_host(host, port, realhost);
- if (p != NULL)
- return p;
-
- random_init();
-
- if (!do_ssh_init())
- return "Protocol initialisation error";
-
- /* Exchange keys and login */
- do {
- get_packet();
- if (s == INVALID_SOCKET)
- return "Connection closed by remote host";
- } while (!do_ssh1_login(NULL, 0, 1));
-
- if (ssh_state == SSH_STATE_CLOSED) {
- closesocket(s);
- s = INVALID_SOCKET;
- return "Session initialisation error";
- }
-
- /* Execute command */
- sprintf(buf, "Sending command: %.100s", cmd);
- logevent(buf);
- send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
-
- return NULL;
+ if (option == LD_ECHO)
+ return ssh_echoing;
+ if (option == LD_EDIT)
+ return ssh_editing;
+ return FALSE;
}
-static SOCKET ssh_socket(void) { return s; }
-
-static int ssh_sendok(void) { return ssh_send_ok; }
+static int ssh_return_exitcode(void)
+{
+ return ssh_exitcode;
+}
Backend ssh_backend = {
ssh_init,
- ssh_msg,
ssh_send,
+ ssh_sendbuffer,
ssh_size,
ssh_special,
ssh_socket,
- ssh_sendok
+ ssh_return_exitcode,
+ ssh_sendok,
+ ssh_ldisc,
+ ssh_unthrottle,
+ 22
};