X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/374330e25a6b51c40436fa869a381dd510790f6e..4b1e8accb59e8f3b35d24f7ae207325a49cb3cc6:/ssh.c diff --git a/ssh.c b/ssh.c index f80055c9..5a7dcf24 100644 --- a/ssh.c +++ b/ssh.c @@ -1,8 +1,12 @@ +#include #include #include -#include +#include +#include #include "putty.h" +#include "tree234.h" +#include "ssh.h" #ifndef FALSE #define FALSE 0 @@ -11,7 +15,131 @@ #define TRUE 1 #endif -#include "ssh.h" +#define logevent(s) { logevent(s); \ + if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \ + fprintf(stderr, "%s\n", s); } + +#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \ + (s ? sk_close(s), s = NULL : (void)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 SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */ +#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */ +#define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */ +#define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */ +#define SSH_AGENT_FAILURE 5 /* 0x5 */ +#define SSH_AGENT_SUCCESS 6 /* 0x6 */ +#define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */ +#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */ + +#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_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_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 */ + +#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_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 */ + +#define GET_32BIT(cp) \ + (((unsigned long)(unsigned char)(cp)[0] << 24) | \ + ((unsigned long)(unsigned char)(cp)[1] << 16) | \ + ((unsigned long)(unsigned char)(cp)[2] << 8) | \ + ((unsigned long)(unsigned char)(cp)[3])) + +#define PUT_32BIT(cp, value) { \ + (cp)[0] = (unsigned char)((value) >> 24); \ + (cp)[1] = (unsigned char)((value) >> 16); \ + (cp)[2] = (unsigned char)((value) >> 8); \ + (cp)[3] = (unsigned char)(value); } + +enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM }; /* Coroutine mechanics for the sillier bits of the code */ #define crBegin1 static int crLine = 0; @@ -29,136 +157,473 @@ } while (0) #define crStop(z) do{ crLine = 0; return (z); }while(0) #define crStopV do{ crLine = 0; return; }while(0) +#define crWaitUntil(c) do { crReturn(0); } while (!(c)) +#define crWaitUntilV(c) do { crReturnV; } while (!(c)) -#ifndef FALSE -#define FALSE 0 -#endif -#ifndef TRUE -#define TRUE 1 -#endif +extern const struct ssh_cipher ssh_3des; +extern const struct ssh_cipher ssh_3des_ssh2; +extern const struct ssh_cipher ssh_des; +extern const struct ssh_cipher ssh_blowfish_ssh1; +extern const struct ssh_cipher ssh_blowfish_ssh2; -static SOCKET s = INVALID_SOCKET; +extern char *x11_init (Socket *, char *, void *); +extern void x11_close (Socket); +extern void x11_send (Socket , char *, int); +extern void x11_invent_auth(char *, int, char *, int); -static unsigned char session_key[32]; -static struct ssh_cipher *cipher = NULL; - -static char *savedhost; +/* + * Ciphers for SSH2. We miss out single-DES because it isn't + * supported; also 3DES and Blowfish are both done differently from + * SSH1. (3DES uses outer chaining; Blowfish has the opposite + * endianness and different-sized keys.) + */ +const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 }; -static enum { - SSH_STATE_BEFORE_SIZE, - SSH_STATE_INTERMED, - SSH_STATE_SESSION -} ssh_state = SSH_STATE_BEFORE_SIZE; +extern const struct ssh_kex ssh_diffiehellman; +const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman }; -static int size_needed = FALSE; +extern const struct ssh_signkey ssh_dss; +const static struct ssh_signkey *hostkey_algs[] = { &ssh_dss }; -static void s_write (char *buf, int len) { - while (len > 0) { - int i = send (s, buf, len, 0); - if (i > 0) - len -= i, buf += i; - } -} +extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy; -static int s_read (char *buf, int len) { - int ret = 0; - while (len > 0) { - int i = recv (s, buf, len, 0); - if (i > 0) - len -= i, buf += i, ret += i; - else - return i; - } - return ret; +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 +}; +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 }; + +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; } +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 +}; +extern const struct ssh_compress ssh_zlib; +const static struct ssh_compress *compressions[] = { + &ssh_zlib, &ssh_comp_none }; + +enum { /* channel types */ + CHAN_MAINSESSION, + CHAN_X11, + CHAN_AGENT, +}; -static void c_write (char *buf, int len) { - while (len--) { - int new_head = (inbuf_head + 1) & INBUF_MASK; - int c = (unsigned char) *buf; - if (new_head != inbuf_reap) { - inbuf[inbuf_head] = *buf++; - inbuf_head = new_head; - } - } -} +/* + * 2-3-4 tree storing channels. + */ +struct ssh_channel { + unsigned remoteid, localid; + int type; + int closes; + struct ssh2_data_channel { + unsigned char *outbuffer; + unsigned outbuflen, outbufsize; + unsigned remwindow, remmaxpkt; + } v2; + union { + struct ssh_agent_channel { + unsigned char *message; + unsigned char msglen[4]; + int lensofar, totallen; + } a; + struct ssh_x11_channel { + Socket s; + } x11; + } u; +}; struct Packet { long length; int type; - unsigned long crc; unsigned char *data; unsigned char *body; + long savedpos; long maxlen; }; -static struct Packet pktin = { 0, 0, 0, NULL, 0 }; -static struct Packet pktout = { 0, 0, 0, NULL, 0 }; +static SHA_State exhash, exhashbase; + +static Socket s = NULL; + +static unsigned char session_key[32]; +static int ssh1_compressing; +static int ssh_agentfwd_enabled; +static int ssh_X11_fwd_enabled; +static const struct ssh_cipher *cipher = NULL; +static const struct ssh_cipher *cscipher = NULL; +static const struct ssh_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; +int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = 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 void ssh_protocol(unsigned char *in, int inlen, int ispkt); +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 int ssh_version; +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 void ssh2_try_send(struct ssh_channel *c); +static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); + +static int (*s_rdpkt)(unsigned char **data, int *datalen); + +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 void ssh_gotdata(unsigned char *data, int datalen) { - static long len, biglen, to_read; - static unsigned char c, *p; - static int i, pad; - static char padding[8]; - static unsigned char word[4]; +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 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); +} + +/* + * Collect incoming data in the incoming packet buffer. + * Decipher and verify the packet when it is completely read. + * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets. + * Update the *data and *datalen variables. + * Return the additional nr of bytes needed, or 0 when + * a complete packet is available. + */ +static int ssh1_rdpkt(unsigned char **data, int *datalen) +{ + struct rdpkt1_state_tag *st = &rdpkt1_state; crBegin; - while (1) { - for (i = len = 0; i < 4; i++) { - while (datalen == 0) - crReturnV; - len = (len << 8) + *data; - data++, datalen--; - } - pad = 8 - (len%8); +next_packet: - biglen = len + pad; + pktin.type = 0; + pktin.length = 0; - len -= 5; /* type and CRC */ + for (st->i = st->len = 0; st->i < 4; st->i++) { + while ((*datalen) == 0) + crReturn(4-st->i); + st->len = (st->len << 8) + **data; + (*data)++, (*datalen)--; + } - pktin.length = len; - if (pktin.maxlen < biglen) { - pktin.maxlen = biglen; - pktin.data = (pktin.data == NULL ? malloc(biglen) : - realloc(pktin.data, biglen)); +#ifdef FWHACK + if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */ + st->len = 0x300; /* big enough to carry to end */ + } +#endif + + st->pad = 8 - (st->len % 8); + st->biglen = st->len + st->pad; + pktin.length = st->len - 5; + + 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"); + } + + st->to_read = st->biglen; + st->p = pktin.data; + while (st->to_read > 0) { + st->chunk = st->to_read; + while ((*datalen) == 0) + 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) + cipher->decrypt(pktin.data, st->biglen); +#if 0 + debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad)); + for (st->i = 0; st->i < st->biglen; st->i++) + debug((" %02x", (unsigned char)pktin.data[st->i])); + debug(("\r\n")); +#endif + + 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; + + if (ssh1_compressing) { + unsigned char *decompblk; + int decomplen; +#if 0 + int i; + debug(("Packet payload pre-decompression:\n")); + for (i = -1; i < pktin.length; i++) + debug((" %02x", (unsigned char)pktin.body[i])); + debug(("\r\n")); +#endif + 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"); } - p = pktin.data, to_read = biglen; - while (to_read > 0) { - static int chunk; - chunk = to_read; - while (datalen == 0) - crReturnV; - if (chunk > datalen) - chunk = datalen; - memcpy(p, data, chunk); - data += chunk; - datalen -= chunk; - p += chunk; - to_read -= chunk; - } + memcpy(pktin.body-1, decompblk, decomplen); + sfree(decompblk); + pktin.length = decomplen-1; +#if 0 + debug(("Packet payload post-decompression:\n")); + for (i = -1; i < pktin.length; i++) + debug((" %02x", (unsigned char)pktin.body[i])); + debug(("\r\n")); +#endif + } - if (cipher) - cipher->decrypt(pktin.data, biglen); + 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) { + bombout(("Received data packet with bogus string length")); + crReturn(0); + } + } - pktin.type = pktin.data[pad]; - pktin.body = pktin.data+pad+1; + pktin.type = pktin.body[-1]; + + if (pktin.type == SSH1_MSG_DEBUG) { + /* log debug message */ + char buf[80]; + int strlen = GET_32BIT(pktin.body); + strcpy(buf, "Remote: "); + if (strlen > 70) strlen = 70; + memcpy(buf+8, pktin.body+4, strlen); + buf[8+strlen] = '\0'; + logevent(buf); + goto next_packet; + } else if (pktin.type == SSH1_MSG_IGNORE) { + /* do nothing */ + goto next_packet; + } - if (pktin.type == 36) { /* SSH_MSG_DEBUG */ - /* FIXME: log it */ - } else - ssh_protocol(NULL, 0, 1); + crFinish(0); +} + +static int ssh2_rdpkt(unsigned char **data, int *datalen) +{ + struct rdpkt2_state_tag *st = &rdpkt2_state; + + crBegin; + +next_packet: + pktin.type = 0; + pktin.length = 0; + if (sccipher) + st->cipherblk = sccipher->blksize; + else + 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"); } - crFinishV; + + /* + * Acquire and decrypt the first block of the packet. This will + * contain the length and padding details. + */ + for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { + while ((*datalen) == 0) + crReturn(st->cipherblk-st->i); + pktin.data[st->i] = *(*data)++; + (*datalen)--; + } +#ifdef FWHACK + if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */ + /* FIXME */ + } +#endif + if (sccipher) + sccipher->decrypt(pktin.data, st->cipherblk); + + /* + * Now get the length and padding figures. + */ + st->len = GET_32BIT(pktin.data); + st->pad = pktin.data[4]; + + /* + * This enables us to deduce the payload length. + */ + st->payload = st->len - st->pad - 1; + + pktin.length = st->payload + 5; + + /* + * So now we can work out the total packet length. + */ + st->packetlen = st->len + 4; + st->maclen = scmac ? scmac->len : 0; + + /* + * Adjust memory allocation if packet is too big. + */ + 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 (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) { + while ((*datalen) == 0) + crReturn(st->packetlen + st->maclen - st->i); + pktin.data[st->i] = *(*data)++; + (*datalen)--; + } + /* Decrypt everything _except_ the MAC. */ + if (sccipher) + sccipher->decrypt(pktin.data + st->cipherblk, + st->packetlen - st->cipherblk); + +#if 0 + debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad)); + for (st->i = 0; st->i < st->packetlen; st->i++) + debug((" %02x", (unsigned char)pktin.data[st->i])); + debug(("\r\n")); +#endif + + /* + * Check the MAC. + */ + 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); +#if 0 + debug(("Post-decompression payload:\r\n")); + for (st->i = 0; st->i < newlen; st->i++) + debug((" %02x", (unsigned char)pktin.data[5+st->i])); + debug(("\r\n")); +#endif + + 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); } -static void s_wrpkt_start(int type, int len) { +static void ssh1_pktout_size(int len) { int pad, biglen; len += 5; /* type and CRC */ @@ -168,173 +633,1916 @@ static void s_wrpkt_start(int type, int len) { pktout.length = len-5; if (pktout.maxlen < biglen) { pktout.maxlen = biglen; - pktout.data = (pktout.data == NULL ? malloc(biglen) : - realloc(pktout.data, biglen)); +#ifdef MSCRYPTOAPI + /* Allocate enough buffer space for extra block + * for MS CryptEncrypt() */ + pktout.data = (pktout.data == NULL ? smalloc(biglen+12) : + srealloc(pktout.data, biglen+12)); +#else + 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) { int pad, len, biglen, i; unsigned long crc; + pktout.body[-1] = pktout.type; + + if (ssh1_compressing) { + unsigned char *compblk; + int complen; +#if 0 + debug(("Packet payload pre-compression:\n")); + for (i = -1; i < pktout.length; i++) + debug((" %02x", (unsigned char)pktout.body[i])); + debug(("\r\n")); +#endif + zlib_compress_block(pktout.body-1, pktout.length+1, + &compblk, &complen); + ssh1_pktout_size(complen-1); + memcpy(pktout.body-1, compblk, complen); + sfree(compblk); +#if 0 + debug(("Packet payload post-compression:\n")); + for (i = -1; i < pktout.length; i++) + debug((" %02x", (unsigned char)pktout.body[i])); + debug(("\r\n")); +#endif + } + len = pktout.length + 5; /* type and CRC */ pad = 8 - (len%8); biglen = len + pad; - pktout.body[-1] = pktout.type; for (i=0; iencrypt(pktout.data+4, biglen); - pktout.data[biglen+0] = (unsigned char) ((crc >> 24) & 0xFF); - pktout.data[biglen+1] = (unsigned char) ((crc >> 16) & 0xFF); - pktout.data[biglen+2] = (unsigned char) ((crc >> 8) & 0xFF); - pktout.data[biglen+3] = (unsigned char) (crc & 0xFF); + sk_write(s, pktout.data, biglen+4); +} - pktout.data[0] = (len >> 24) & 0xFF; - pktout.data[1] = (len >> 16) & 0xFF; - pktout.data[2] = (len >> 8) & 0xFF; - pktout.data[3] = len & 0xFF; +/* + * Construct a packet with the specified contents and + * send it to the server. + */ +static void send_packet(int pkttype, ...) +{ + 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) { + switch (argtype) { + case PKT_INT: + (void) va_arg(args, int); + pktlen += 4; + break; + case PKT_CHAR: + (void) va_arg(args, char); + pktlen++; + break; + case PKT_DATA: + (void) va_arg(args, unsigned char *); + arglen = va_arg(args, int); + pktlen += arglen; + break; + case PKT_STR: + argp = va_arg(args, unsigned char *); + arglen = strlen(argp); + pktlen += 4 + arglen; + break; + case PKT_BIGNUM: + bn = va_arg(args, 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) { + switch (argtype) { + case PKT_INT: + argint = va_arg(args, int); + PUT_32BIT(p, argint); + p += 4; + break; + case PKT_CHAR: + argchar = va_arg(args, unsigned char); + *p = argchar; + p++; + break; + case PKT_DATA: + argp = va_arg(args, unsigned char *); + arglen = va_arg(args, int); + memcpy(p, argp, arglen); + p += arglen; + break; + case PKT_STR: + argp = va_arg(args, 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); + break; + } + } + va_end(args); - if (cipher) - cipher->encrypt(pktout.data+4, biglen); + s_wrpkt(); +} + +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 +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); +} + +/* + * SSH2 packet construction functions. + */ +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"); + } +} +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); +} +static void ssh2_pkt_init(int pkt_type) { + pktout.length = 5; + ssh2_pkt_addbyte((unsigned char)pkt_type); +} +static void ssh2_pkt_addbool(unsigned char value) { + ssh2_pkt_adddata(&value, 1); +} +static void ssh2_pkt_adduint32(unsigned long value) { + unsigned char x[4]; + PUT_32BIT(x, value); + ssh2_pkt_adddata(x, 4); +} +static void ssh2_pkt_addstring_start(void) { + ssh2_pkt_adduint32(0); + pktout.savedpos = pktout.length; +} +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); +} +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); +} +static void ssh2_pkt_addstring(char *data) { + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_str(data); +} +static char *ssh2_mpint_fmt(Bignum b, int *len) { + unsigned char *p; + int i, n = b[0]; + p = smalloc(n * 2 + 1); + if (!p) + 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; + } + 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; + return p; +} +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); + sfree(p); +} +static void ssh2_pkt_send(void) { + int cipherblk, maclen, padding, i; + static unsigned long outgoing_sequence = 0; + + /* + * Compress packet payload. + */ +#if 0 + debug(("Pre-compression payload:\r\n")); + for (i = 5; i < pktout.length; i++) + debug((" %02x", (unsigned char)pktout.data[i])); + debug(("\r\n")); +#endif + { + 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 */ + padding = 4; + 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(); + 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 + + if (cscipher) + cscipher->encrypt(pktout.data, pktout.length + padding); + + sk_write(s, pktout.data, pktout.length + padding + maclen); +} + +#if 0 +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")); + sfree(p); +} +#endif + +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); + sfree(p); +} + +/* + * SSH2 packet decode functions. + */ +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); + pktin.savedpos += 4; + 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); + pktin.savedpos += 4; + if (pktin.length - pktin.savedpos < *length) + return; + *p = pktin.data+pktin.savedpos; + pktin.savedpos += *length; +} +static Bignum ssh2_pkt_getmp(void) { + char *p; + int i, j, length; + Bignum b; + + ssh2_pkt_getstring(&p, &length); + if (!p) + return NULL; + if (p[0] & 0x80) { + bombout(("internal error: Can't handle negative mpints")); + return NULL; + } + 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]); + } + while (b[0] > 1 && b[b[0]] == 0) b[0]--; + return b; +} + +static int do_ssh_init(unsigned char c) { + static char *vsp; + static char version[10]; + static char vstring[80]; + static char vlog[sizeof(vstring)+20]; + static int i; + + crBegin; + + /* Search for the string "SSH-" in the input. */ + 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 */ + } + + strcpy(vstring, "SSH-"); + vsp = vstring+4; + i = 0; + while (1) { + crReturn(1); /* get another char */ + if (vsp < vstring+sizeof(vstring)-1) + *vsp++ = c; + if (i >= 0) { + if (c == '-') { + version[i] = '\0'; + i = -1; + } else if (i < sizeof(version)-1) + version[i++] = c; + } + else if (c == '\n') + break; + } + + ssh_agentfwd_enabled = FALSE; + rdpkt2_state.incoming_sequence = 0; + + *vsp = 0; + sprintf(vlog, "Server version: %s", vstring); + vlog[strcspn(vlog, "\r\n")] = '\0'; + logevent(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(&exhashbase); + /* + * Hash our version string and their version string. + */ + sha_string(&exhashbase, verstring, strlen(verstring)); + sha_string(&exhashbase, 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"); + sk_write(s, vstring, strlen(vstring)); + 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"); + sk_write(s, vstring, strlen(vstring)); + ssh_protocol = ssh1_protocol; + ssh_version = 1; + s_rdpkt = ssh1_rdpkt; + } + ssh_state = SSH_STATE_BEFORE_SIZE; + + crFinish(0); +} + +static void ssh_gotdata(unsigned char *data, int datalen) +{ + crBegin; + + /* + * 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. + */ + while (1) { + int ret; + if (datalen == 0) + crReturnV; /* more data please */ + ret = do_ssh_init(*data); + data++; datalen--; + if (ret == 0) + break; + } + + /* + * 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. + */ + if (datalen == 0) + crReturnV; + while (1) { + while (datalen > 0) { + if ( s_rdpkt(&data, &datalen) == 0 ) { + ssh_protocol(NULL, 0, 1); + if (ssh_state == SSH_STATE_CLOSED) { + return; + } + } + } + crReturnV; + } + crFinishV; +} + +static int ssh_receive(Socket skt, int urgent, char *data, int len) { + if (urgent==3) { + /* A socket error has occurred. */ + ssh_state = SSH_STATE_CLOSED; + sk_close(s); + s = NULL; + connection_fatal(data); + return 0; + } else if (!len) { + /* Connection has closed. */ + ssh_state = SSH_STATE_CLOSED; + sk_close(s); + s = NULL; + return 0; + } + ssh_gotdata (data, len); + if (ssh_state == SSH_STATE_CLOSED) { + if (s) { + sk_close(s); + s = NULL; + } + return 0; + } + return 1; +} + +/* + * 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) +{ + SockAddr addr; + char *err; +#ifdef FWHACK + char *FWhost; + int FWport; +#endif + + savedhost = smalloc(1+strlen(host)); + if (!savedhost) + fatalbox("Out of memory"); + strcpy(savedhost, host); + + if (port < 0) + port = 22; /* default ssh port */ + savedport = port; + +#ifdef FWHACK + FWhost = host; + FWport = port; + host = FWSTR; + port = 23; +#endif + + /* + * Try to find host. + */ + addr = sk_namelookup(host, realhost); + if ( (err = sk_addr_error(addr)) ) + return err; + +#ifdef FWHACK + *realhost = FWhost; +#endif + + /* + * Open socket. + */ + s = sk_new(addr, port, 0, 1, ssh_receive); + if ( (err = sk_socket_error(s)) ) + 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; +} + +/* + * Handle the key exchange and user authentication phases. + */ +static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) +{ + 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; + static char username[100]; + + 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); + } + + 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 = 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"); + + 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; + } + + 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..."); + + 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 int pos = 0; + static char c; + if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { + c_write("login as: ", 10); + 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("\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; + } + } + c_write("\r\n", 2); + username[strcspn(username, "\n\r")] = '\0'; + } else { + strncpy(username, cfg.username, 99); + username[99] = '\0'; + } + + send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END); + { + 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(userlog, strlen(userlog)); + } + } + } + + crWaitUntil(ispkt); + + tried_publickey = 0; + + 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; + static char *commentp; + static int commentlen; + + { 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); + 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; + 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++ = 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); + sfree(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); + sfree(ret); + crWaitUntil(ispkt); + if (pktin.type == SSH1_SMSG_SUCCESS) { + logevent("Pageant's response accepted"); + if (flags & FLAG_VERBOSE) { + c_write("Authenticated using RSA key \"", + 29); + c_write(commentp, commentlen); + c_write("\" from agent\r\n", 14); + } + 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 (pktin.type == SSH1_SMSG_FAILURE && + cfg.try_tis_auth && + (supported_auths_mask & (1< sizeof(prompt)-1) + challengelen = sizeof(prompt)-1; /* prevent overrun */ + memcpy(prompt, pktin.body+4, challengelen); + prompt[challengelen] = '\0'; + } + } + if (pktin.type == SSH1_SMSG_FAILURE && + cfg.try_tis_auth && + (supported_auths_mask & (1< sizeof(prompt)-1) + challengelen = sizeof(prompt)-1; /* prevent overrun */ + memcpy(prompt, pktin.body+4, challengelen); + strncpy(prompt + 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("Trying public key authentication.\r\n", 35); + if (!rsakey_encrypted(cfg.keyfile, &comment)) { + if (flags & FLAG_VERBOSE) + c_write("No passphrase required.\r\n", 25); + goto tryauth; + } + sprintf(prompt, "Passphrase for key \"%.100s\": ", comment); + sfree(comment); + } + + if (ssh_get_password) { + 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); + } + } else { + c_write(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: + 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); + } + + 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, NULL, 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 */ + } + + /* + * 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("Server refused our public key.\r\n", 32); + 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 */ + + 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("Failed to authenticate with our public key.\r\n", + 45); + continue; /* go and try password */ + } else if (pktin.type != SSH1_SMSG_SUCCESS) { + bombout(("Bizarre response to RSA authentication response")); + crReturn(0); + } + + break; /* we're through! */ + } 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); + logevent("Authentication refused"); + } else if (pktin.type == SSH1_MSG_DISCONNECT) { + logevent("Received disconnect request"); + ssh_state = SSH_STATE_CLOSED; + crReturn(1); + } else if (pktin.type != SSH1_SMSG_SUCCESS) { + bombout(("Strange packet received, type %d", pktin.type)); + crReturn(0); + } + } + + logevent("Authentication successful"); + + crFinish(1); +} + +void sshfwd_close(struct ssh_channel *c) { + if (c) { + 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("X11 connection terminated"); + } + } +} + +void 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); + } else { + ssh2_add_channel_data(c, buf, len); + ssh2_try_send(c); + } +} + +static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { + crBegin; + + random_init(); + + while (!do_ssh1_login(in, inlen, ispkt)) { + crReturnV; + } + if (ssh_state == SSH_STATE_CLOSED) + 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)); + send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING, + PKT_STR, proto, PKT_STR, data, + PKT_INT, 0, + 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 (!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) { + bombout(("Protocol confusion")); + crReturnV; + } else if (pktin.type == SSH1_SMSG_FAILURE) { + c_write("Server refused to allocate pty\r\n", 32); + ssh_editing = ssh_echoing = 1; + } + logevent("Allocated pty"); + } else { + ssh_editing = ssh_echoing = 1; + } - s_write(pktout.data, biglen+4); -} + 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("Server refused to compress\r\n", 32); + } + logevent("Started compression"); + ssh1_compressing = TRUE; + zlib_compress_init(); + zlib_decompress_init(); + } -static int do_ssh_init(void) { - char c; - char version[10]; - char vstring[40]; - int i; + 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"); -#ifdef FWHACK - 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; - } -#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 - if (s_read(&c,1) != 1 || c != '-') return 0; - i = 0; + ssh_state = SSH_STATE_SESSION; + if (size_needed) + ssh_size(); + if (eof_needed) + ssh_special(TS_EOF); + + ldisc_send(NULL, 0); /* cause ldisc to notice changes */ + ssh_send_ok = 1; + ssh_channels = newtree234(ssh_channelcmp); while (1) { - if (s_read(&c,1) != 1) - return 0; - if (i >= 0) { - if (c == '-') { - version[i] = '\0'; - i = -1; - } else if (i < sizeof(version)-1) - version[i++] = c; + crReturnV; + if (ispkt) { + if (pktin.type == SSH1_SMSG_STDOUT_DATA || + pktin.type == SSH1_SMSG_STDERR_DATA) { + long len = GET_32BIT(pktin.body); + from_backend(pktin.type == SSH1_SMSG_STDERR_DATA, + pktin.body+4, len); + } else if (pktin.type == SSH1_MSG_DISCONNECT) { + ssh_state = SSH_STATE_CLOSED; + logevent("Received disconnect request"); + 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. */ + unsigned i; + struct ssh_channel *c, *d; + enum234 e; + + 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"); + for (i=1, d = first234(ssh_channels, &e); d; d = next234(&e)) { + if (d->localid > i) + break; /* found a free number */ + i = d->localid + 1; + } + c->remoteid = GET_32BIT(pktin.body); + c->localid = i; + c->closes = 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. */ + unsigned i; + struct ssh_channel *c; + enum234 e; + + /* 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 { + i = 1; + for (c = first234(ssh_channels, &e); c; c = next234(&e)) { + if (c->localid > i) + break; /* found a free number */ + i = c->localid + 1; + } + c = smalloc(sizeof(struct ssh_channel)); + c->remoteid = GET_32BIT(pktin.body); + c->localid = i; + c->closes = 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_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); + send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END); + if ((c->closes == 0) && (c->type == CHAN_X11)) { + logevent("X11 connection closed"); + assert(c->u.x11.s != NULL); + x11_close(c->u.x11.s); + c->u.x11.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) { + switch(c->type) { + case CHAN_X11: + x11_send(c->u.x11.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; + } + } + break; + } + } + } 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) { + send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); + } else { + bombout(("Strange packet received: type %d", pktin.type)); + crReturnV; + } + } else { + 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; + } } - else if (c == '\n') - break; } - sprintf(vstring, "SSH-%s-7.7.7\n", - (strcmp(version, "1.5") <= 0 ? version : "1.5")); - s_write(vstring, strlen(vstring)); + crFinishV; } -static void ssh_protocol(unsigned char *in, int inlen, int ispkt) { - int i, j, len; - unsigned char session_id[16]; - unsigned char *rsabuf, *keystr1, *keystr2; - unsigned char cookie[8]; - struct RSAKey servkey, hostkey; - struct MD5Context md5c; +/* + * Utility routine for decoding comma-separated strings in KEXINIT. + */ +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 */ + } +} + +/* + * SSH2 key creation method. + */ +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, 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); +} - extern struct ssh_cipher ssh_3des; +/* + * Handle the SSH2 transport layer. + */ +static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt) +{ + static int i, len; + static char *str; + static Bignum e, f, K; + static const struct ssh_mac **maclist; + static int nmacs; + static const struct ssh_cipher *cscipher_tobe = NULL; + static const struct ssh_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 first_exchange_hash[20]; + static unsigned char keyspace[40]; + static const struct ssh_cipher *preferred_cipher; + static const struct ssh_compress *preferred_comp; + static int first_kex; crBegin; - random_init(); + first_kex = 1; - while (!ispkt) - crReturnV; - - if (pktin.type != 2) - fatalbox("Public key packet not received"); + /* + * Set up the preferred cipher and compression. + */ + if (cfg.cipher == CIPHER_BLOWFISH) { + preferred_cipher = &ssh_blowfish_ssh2; + } else if (cfg.cipher == CIPHER_DES) { + logevent("Single DES not supported in SSH2; using 3DES"); + preferred_cipher = &ssh_3des_ssh2; + } else if (cfg.cipher == CIPHER_3DES) { + preferred_cipher = &ssh_3des_ssh2; + } else { + /* Shouldn't happen, but we do want to initialise to _something_. */ + preferred_cipher = &ssh_3des_ssh2; + } + if (cfg.compression) + preferred_comp = &ssh_zlib; + else + preferred_comp = &ssh_comp_none; - memcpy(cookie, pktin.body, 8); + /* + * Be prepared to work around the buggy MAC problem. + */ + if (cfg.buggymac) + maclist = buggymacs, nmacs = lenof(buggymacs); + else + maclist = macs, nmacs = lenof(macs); - MD5Init(&md5c); + 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()); + /* 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(","); + } + /* 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(","); + } + /* List client->server encryption algorithms. */ + ssh2_pkt_addstring_start(); + for (i = 0; i < lenof(ciphers)+1; i++) { + const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; + ssh2_pkt_addstring_str(c->name); + if (i < lenof(ciphers)) + ssh2_pkt_addstring_str(","); + } + /* List server->client encryption algorithms. */ + ssh2_pkt_addstring_start(); + for (i = 0; i < lenof(ciphers)+1; i++) { + const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; + ssh2_pkt_addstring_str(c->name); + if (i < lenof(ciphers)) + ssh2_pkt_addstring_str(","); + } + /* List client->server MAC algorithms. */ + ssh2_pkt_addstring_start(); + 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 < 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)+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)+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(); + /* List server->client languages. Empty list. */ + ssh2_pkt_addstring_start(); + /* First KEX packet does _not_ follow, because we're not that brave. */ + ssh2_pkt_addbool(FALSE); + /* Reserved. */ + ssh2_pkt_adduint32(0); - i = makekey(pktin.body+8, &servkey, &keystr1); + exhash = exhashbase; + sha_string(&exhash, pktout.data+5, pktout.length-5); - j = makekey(pktin.body+8+i, &hostkey, &keystr2); + ssh2_pkt_send(); - MD5Update(&md5c, keystr2, hostkey.bytes); - MD5Update(&md5c, keystr1, servkey.bytes); - MD5Update(&md5c, pktin.body, 8); + if (!ispkt) crWaitUntil(ispkt); + sha_string(&exhash, pktin.data+5, pktin.length-5); - MD5Final(session_id, &md5c); + /* + * Now examine the other side's KEXINIT to see what we're up + * to. + */ + if (pktin.type != SSH2_MSG_KEXINIT) { + 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 */ + 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; + } + } + 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; + } + } + ssh2_pkt_getstring(&str, &len); /* client->server cipher */ + for (i = 0; i < lenof(ciphers)+1; i++) { + const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; + if (in_commasep_string(c->name, str, len)) { + cscipher_tobe = c; + break; + } + } + ssh2_pkt_getstring(&str, &len); /* server->client cipher */ + for (i = 0; i < lenof(ciphers)+1; i++) { + const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1]; + if (in_commasep_string(c->name, str, len)) { + sccipher_tobe = c; + break; + } + } + ssh2_pkt_getstring(&str, &len); /* client->server mac */ + 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 < 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)+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)+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; + } + } - for (i=0; i<32; i++) - session_key[i] = random_byte(); + /* + * Currently we only support Diffie-Hellman and DSS, so let's + * bomb out if those aren't selected. + */ + if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) { + bombout(("internal fault: chaos in SSH 2 transport layer")); + crReturn(0); + } - len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); + /* + * Now we begin the fun. Generate and send e for Diffie-Hellman. + */ + e = dh_create_e(); + ssh2_pkt_init(SSH2_MSG_KEXDH_INIT); + ssh2_pkt_addmp(e); + ssh2_pkt_send(); + + crWaitUntil(ispkt); + if (pktin.type != SSH2_MSG_KEXDH_REPLY) { + bombout(("expected key exchange packet from server")); + crReturn(0); + } + ssh2_pkt_getstring(&hostkeydata, &hostkeylen); + f = ssh2_pkt_getmp(); + ssh2_pkt_getstring(&sigdata, &siglen); + + K = dh_find_K(f); + + sha_string(&exhash, hostkeydata, hostkeylen); + sha_mpint(&exhash, e); + sha_mpint(&exhash, f); + sha_mpint(&exhash, K); + SHA_Final(&exhash, exchange_hash); + +#if 0 + debug(("Exchange hash is:\r\n")); + for (i = 0; i < 20; i++) + debug((" %02x", exchange_hash[i])); + debug(("\r\n")); +#endif - rsabuf = malloc(len); - if (!rsabuf) - fatalbox("Out of memory"); + hkey = hostkey->newkey(hostkeydata, hostkeylen); + if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) { + bombout(("Server failed host key check")); + crReturn(0); + } - verify_ssh_host_key(savedhost, &hostkey); + /* + * Expect SSH2_MSG_NEWKEYS from server. + */ + crWaitUntil(ispkt); + if (pktin.type != SSH2_MSG_NEWKEYS) { + bombout(("expected new-keys packet from server")); + crReturn(0); + } - for (i=0; i<32; i++) { - rsabuf[i] = session_key[i]; - if (i < 16) - rsabuf[i] ^= session_id[i]; + /* + * Authenticate remote host: verify host key. (We've already + * checked the signature of the exchange hash.) + */ + 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); - if (hostkey.bytes > servkey.bytes) { - rsaencrypt(rsabuf, 32, &servkey); - rsaencrypt(rsabuf, servkey.bytes, &hostkey); - } else { - rsaencrypt(rsabuf, 32, &hostkey); - rsaencrypt(rsabuf, hostkey.bytes, &servkey); + /* + * Send SSH2_MSG_NEWKEYS. + */ + ssh2_pkt_init(SSH2_MSG_NEWKEYS); + ssh2_pkt_send(); + + /* + * Create and initialise session keys. + */ + cscipher = cscipher_tobe; + sccipher = sccipher_tobe; + csmac = csmac_tobe; + scmac = scmac_tobe; + cscomp = cscomp_tobe; + sccomp = sccomp_tobe; + cscomp->compress_init(); + sccomp->decompress_init(); + /* + * Set IVs after keys. Here we use the exchange hash from the + * _first_ key exchange. + */ + if (first_kex) + memcpy(first_exchange_hash, exchange_hash, sizeof(exchange_hash)); + ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'C', keyspace); + cscipher->setcskey(keyspace); + ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'D', keyspace); + sccipher->setsckey(keyspace); + ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'A', keyspace); + cscipher->setcsiv(keyspace); + ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'B', keyspace); + sccipher->setsciv(keyspace); + ssh2_mkkey(K, exchange_hash, first_exchange_hash, 'E', keyspace); + csmac->setcskey(keyspace); + ssh2_mkkey(K, exchange_hash, first_exchange_hash, '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; - s_wrpkt_start(3, len+15); - pktout.body[0] = 3; /* SSH_CIPHER_3DES */ - memcpy(pktout.body+1, cookie, 8); - pktout.body[9] = (len*8) >> 8; - pktout.body[10] = (len*8) & 0xFF; - memcpy(pktout.body+11, rsabuf, len); - pktout.body[len+11] = pktout.body[len+12] = 0; /* protocol flags */ - pktout.body[len+13] = pktout.body[len+14] = 0; - s_wrpkt(); + /* + * Now we're encrypting. Begin returning 1 to the protocol main + * function so that other things can run on top of the + * transport. If we ever see a KEXINIT, we must go back to the + * start. + */ + do { + crReturn(1); + } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)); + logevent("Server initiated key re-exchange"); + goto begin_key_exchange; - free(rsabuf); + crFinish(1); +} - cipher = &ssh_3des; - cipher->sesskey(session_key); +/* + * Add data to an SSH2 channel output buffer. + */ +static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) { + if (c->v2.outbufsize < + c->v2.outbuflen + len) { + c->v2.outbufsize = + c->v2.outbuflen + len + 1024; + c->v2.outbuffer = srealloc(c->v2.outbuffer, + c->v2.outbufsize); + } + memcpy(c->v2.outbuffer + c->v2.outbuflen, + buf, len); + c->v2.outbuflen += len; +} + +/* + * Attempt to send data on an SSH2 channel. + */ +static void ssh2_try_send(struct ssh_channel *c) { + while (c->v2.remwindow > 0 && + c->v2.outbuflen > 0) { + unsigned len = c->v2.remwindow; + if (len > c->v2.outbuflen) + len = c->v2.outbuflen; + if (len > c->v2.remmaxpkt) + len = c->v2.remmaxpkt; + ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(c->v2.outbuffer, len); + ssh2_pkt_send(); + c->v2.outbuflen -= len; + memmove(c->v2.outbuffer, c->v2.outbuffer+len, + c->v2.outbuflen); + c->v2.remwindow -= len; + } +} - do { crReturnV; } while (!ispkt); +/* + * 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; - if (pktin.type != 14) - fatalbox("Encryption not successfully enabled"); + crBegin; - fflush(stdout); - { + /* + * Request userauth protocol, and await a response to it. + */ + ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); + ssh2_pkt_addstring("ssh-userauth"); + ssh2_pkt_send(); + crWaitUntilV(ispkt); + 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.) + */ + while (1) { + /* + * Get a username and a password. + */ static char username[100]; + static char password[100]; static int pos = 0; static char c; - if (!*cfg.username) { + + if ((flags & FLAG_INTERACTIVE) && !*cfg.username) { c_write("login as: ", 10); + ssh_send_ok = 1; while (pos >= 0) { - do { crReturnV; } while (ispkt); + crWaitUntilV(!ispkt); while (inlen--) switch (c = *in++) { case 10: case 13: username[pos] = 0; @@ -357,7 +2565,8 @@ static void ssh_protocol(unsigned char *in, int inlen, int ispkt) { exit(0); break; default: - if (c >= ' ' && c <= '~' && pos < 40) { + if (((c >= ' ' && c <= '~') || + ((unsigned char)c >= 160)) && pos < 40) { username[pos++] = c; c_write(&c, 1); } @@ -370,325 +2579,565 @@ static void ssh_protocol(unsigned char *in, int inlen, int ispkt) { char stuff[200]; strncpy(username, cfg.username, 99); username[99] = '\0'; - sprintf(stuff, "Sent username \"%s\".\r\n", username); - c_write(stuff, strlen(stuff)); + if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { + sprintf(stuff, "Using username \"%s\".\r\n", username); + c_write(stuff, strlen(stuff)); + } } - s_wrpkt_start(4, 4+strlen(username)); - pktout.body[0] = pktout.body[1] = pktout.body[2] = 0; - pktout.body[3] = strlen(username); - memcpy(pktout.body+4, username, strlen(username)); - s_wrpkt(); - } - - do { crReturnV; } while (!ispkt); - while (pktin.type == 15) { - static char password[100]; - static int pos; - static char c; - c_write("password: ", 10); - pos = 0; - while (pos >= 0) { - do { crReturnV; } while (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 <= '~' && pos < 40) - password[pos++] = c; - break; - } + if (ssh_get_password) { + char prompt[200]; + sprintf(prompt, "%.90s@%.90s's password: ", 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); + 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: + 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); } - c_write("\r\n", 2); - s_wrpkt_start(9, 4+strlen(password)); - pktout.body[0] = pktout.body[1] = pktout.body[2] = 0; - pktout.body[3] = strlen(password); - memcpy(pktout.body+4, password, strlen(password)); - s_wrpkt(); - memset(password, 0, strlen(password)); - do { crReturnV; } while (!ispkt); - if (pktin.type == 15) { + + 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(); + + crWaitUntilV(ispkt); + if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) { c_write("Access denied\r\n", 15); - } else if (pktin.type != 14) { - fatalbox("Strange packet received, type %d", pktin.type); - } + logevent("Authentication refused"); + } else + break; } - i = strlen(cfg.termtype); - s_wrpkt_start(10, i+5*4+1); - pktout.body[0] = (i >> 24) & 0xFF; - pktout.body[1] = (i >> 16) & 0xFF; - pktout.body[2] = (i >> 8) & 0xFF; - pktout.body[3] = i & 0xFF; - memcpy(pktout.body+4, cfg.termtype, i); - i += 4; - pktout.body[i++] = (rows >> 24) & 0xFF; - pktout.body[i++] = (rows >> 16) & 0xFF; - pktout.body[i++] = (rows >> 8) & 0xFF; - pktout.body[i++] = rows & 0xFF; - pktout.body[i++] = (cols >> 24) & 0xFF; - pktout.body[i++] = (cols >> 16) & 0xFF; - pktout.body[i++] = (cols >> 8) & 0xFF; - pktout.body[i++] = cols & 0xFF; - memset(pktout.body+i, 0, 9); /* 0 pixwidth, 0 pixheight, 0.b endofopt */ - s_wrpkt(); - ssh_state = SSH_STATE_INTERMED; - do { crReturnV; } while (!ispkt); - if (pktin.type != 14 && pktin.type != 15) { - fatalbox("Protocol confusion"); - } else if (pktin.type == 15) { - c_write("Server refused to allocate pty\r\n", 32); + /* + * Now we're authenticated for the connection protocol. The + * connection protocol will automatically have started at this + * point; there's no need to send SERVICE_REQUEST. + */ + + /* + * So now create a channel with a session in it. + */ + mainchan = smalloc(sizeof(struct ssh_channel)); + mainchan->localid = 100; /* as good as any */ + ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); + ssh2_pkt_addstring("session"); + ssh2_pkt_adduint32(mainchan->localid); + ssh2_pkt_adduint32(0x8000UL); /* our window size */ + ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */ + ssh2_pkt_send(); + crWaitUntilV(ispkt); + if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { + bombout(("Server refused to open a session")); + crReturnV; + /* FIXME: error data comes back in FAILURE packet */ + } + if (ssh2_pkt_getuint32() != mainchan->localid) { + bombout(("Server's channel confirmation cited wrong channel")); + crReturnV; } + mainchan->remoteid = ssh2_pkt_getuint32(); + mainchan->type = CHAN_MAINSESSION; + mainchan->closes = 0; + mainchan->v2.remwindow = ssh2_pkt_getuint32(); + mainchan->v2.remmaxpkt = ssh2_pkt_getuint32(); + mainchan->v2.outbuffer = NULL; + mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0; + ssh_channels = newtree234(ssh_channelcmp); + add234(ssh_channels, mainchan); + logevent("Opened channel for session"); - s_wrpkt_start(12, 0); - s_wrpkt(); + /* + * Potentially enable X11 forwarding. + */ + 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->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(("Server got confused by X11 forwarding request")); + crReturnV; + } + logevent("X11 forwarding refused"); + } else { + logevent("X11 forwarding enabled"); + ssh_X11_fwd_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->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(("Server got confused by pty request")); + crReturnV; + } + c_write("Server refused to allocate pty\r\n", 32); + ssh_editing = ssh_echoing = 1; + } else { + logevent("Allocated pty"); + } + } else { + ssh_editing = ssh_echoing = 1; + } + + /* + * Start a shell or a remote command. + */ + ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); + ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */ + if (*cfg.remote_cmd) { + ssh2_pkt_addstring("exec"); + ssh2_pkt_addbool(1); /* want reply */ + ssh2_pkt_addstring(cfg.remote_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->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(("Server got confused by shell/command request")); + crReturnV; + } + bombout(("Server refused to start a shell/command")); + crReturnV; + } else { + logevent("Started a shell/command"); + } ssh_state = SSH_STATE_SESSION; if (size_needed) ssh_size(); + if (eof_needed) + ssh_special(TS_EOF); + /* + * Transfer data! + */ + ldisc_send(NULL, 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 == 17 || pktin.type == 18) { - long len = 0; - for (i = 0; i < 4; i++) - len = (len << 8) + pktin.body[i]; - c_write(pktin.body+4, len); - } else if (pktin.type == 1) { - /* SSH_MSG_DISCONNECT: do nothing */ - } else if (pktin.type == 14) { - /* SSH_MSG_SUCCESS: may be from EXEC_SHELL on some servers */ - } else if (pktin.type == 15) { - /* SSH_MSG_FAILURE: may be from EXEC_SHELL on some servers - * if no pty is available or in other odd cases. Ignore */ - } else if (pktin.type == 20) { - /* EXITSTATUS */ - s_wrpkt_start(33, 0); - s_wrpkt(); + if (pktin.type == SSH2_MSG_CHANNEL_DATA || + 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) { + switch (c->type) { + case CHAN_MAINSESSION: + from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA, + data, length); + break; + case CHAN_X11: + x11_send(c->u.x11.s, data, length); + break; + } + /* + * Enlarge the window again at the remote + * side, just in case it ever runs down and + * they fail to send us any more data. + */ + ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_adduint32(length); + ssh2_pkt_send(); + } + } else if (pktin.type == SSH2_MSG_DISCONNECT) { + ssh_state = SSH_STATE_CLOSED; + logevent("Received disconnect message"); + crReturnV; + } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { + continue; /* exit status et al; ignore (FIXME?) */ + } 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 (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { + unsigned i = ssh2_pkt_getuint32(); + struct ssh_channel *c; + enum234 e; + + c = find234(ssh_channels, &i, ssh_channelfind); + if (!c) + continue; /* nonexistent channel */ + if (c->closes == 0) { + ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(c->remoteid); + ssh2_pkt_send(); + } + /* Do pre-close processing on the channel. */ + switch (c->type) { + case CHAN_MAINSESSION: + break; /* nothing to see here, move along */ + case CHAN_X11: + break; + } + del234(ssh_channels, c); + sfree(c->v2.outbuffer); + sfree(c); + + /* + * See if that was the last channel left open. + */ + c = first234(ssh_channels, &e); + if (!c) { + 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(); + ssh_state = SSH_STATE_CLOSED; + crReturnV; + } + continue; /* remote sends close; ignore (FIXME) */ + } else 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 */ + mainchan->v2.remwindow += ssh2_pkt_getuint32(); + try_send = TRUE; + } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) { + char *type; + int typelen; + char *error = NULL; + struct ssh_channel *c; + ssh2_pkt_getstring(&type, &typelen); + c = smalloc(sizeof(struct ssh_channel)); + + 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 { + error = "Unsupported channel type requested"; + } + + c->remoteid = ssh2_pkt_getuint32(); + 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 { + struct ssh_channel *d; + unsigned i; + enum234 e; + + for (i=1, d = first234(ssh_channels, &e); d; + d = next234(&e)) { + if (d->localid > i) + break; /* found a free number */ + i = d->localid + 1; + } + c->localid = i; + c->closes = 0; + c->v2.remwindow = ssh2_pkt_getuint32(); + c->v2.remmaxpkt = ssh2_pkt_getuint32(); + c->v2.outbuffer = NULL; + c->v2.outbuflen = c->v2.outbufsize = 0; + 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(0x8000UL); /* our window size */ + 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 { - s_wrpkt_start(16, 4+inlen); - pktout.body[0] = (inlen >> 24) & 0xFF; - pktout.body[1] = (inlen >> 16) & 0xFF; - pktout.body[2] = (inlen >> 8) & 0xFF; - pktout.body[3] = inlen & 0xFF; - memcpy(pktout.body+4, in, inlen); - s_wrpkt(); + /* + * We have spare data. Add it to the channel buffer. + */ + ssh2_add_channel_data(mainchan, in, inlen); + try_send = TRUE; } + if (try_send) { + enum234 e; + struct ssh_channel *c; + /* + * Try to send data on all channels if we can. + */ + for (c = first234(ssh_channels, &e); c; c = next234(&e)) + ssh2_try_send(c); + } } crFinishV; } /* - * 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(). + * Handle the top-level SSH2 protocol. + */ +static void ssh2_protocol(unsigned char *in, int inlen, int ispkt) +{ + if (do_ssh2_transport(in, inlen, ispkt) == 0) + return; + do_ssh2_authconn(in, inlen, ispkt); +} + +/* + * Called to set up the connection. * * Returns an error message, or NULL on success. - * - * Also places the canonical host name into `realhost'. */ -static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) { - SOCKADDR_IN addr; - struct hostent *h; - unsigned long a; -#ifdef FWHACK - char *FWhost; - int FWport; -#endif - - savedhost = malloc(1+strlen(host)); - if (!savedhost) - fatalbox("Out of memory"); - strcpy(savedhost, host); - -#ifdef FWHACK - FWhost = host; - FWport = port; - host = FWSTR; - port = 23; -#endif - - /* - * 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); - - if (port < 0) - port = 22; /* default ssh port */ - - /* - * 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); - } +static char *ssh_init (char *host, int port, char **realhost) { + char *p; + +#ifdef MSCRYPTOAPI + if(crypto_startup() == 0) + return "Microsoft high encryption pack not installed!"; #endif - if (!do_ssh_init()) - return "Protocol initialisation error"; + ssh_send_ok = 0; + ssh_editing = 0; + ssh_echoing = 0; - if (WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR) - switch (WSAGetLastError()) { - case WSAENETDOWN: return "Network is down"; - default: return "WSAAsyncSelect(): unknown error"; - } + p = connect_to_host(host, port, realhost); + if (p != NULL) + return p; return NULL; } /* - * Process a WM_NETEVENT message. Will return 0 if the connection - * has closed, or <0 for a socket error. - */ -static int ssh_msg (WPARAM wParam, LPARAM lParam) { - int ret; - char buf[256]; - - if (s == INVALID_SOCKET) /* how the hell did we get here?! */ - return -5000; - - if (WSAGETSELECTERROR(lParam) != 0) - return -WSAGETSELECTERROR(lParam); - - switch (WSAGETSELECTEVENT(lParam)) { - case FD_READ: - 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; /* can't happen, in theory */ - } - ssh_gotdata (buf, ret); - return 1; - case FD_CLOSE: - s = INVALID_SOCKET; - return 0; - } - return 1; /* shouldn't happen, but WTF */ -} - -/* * Called to send data down the Telnet connection. */ static void ssh_send (char *buf, int len) { - if (s == INVALID_SOCKET) + if (s == NULL || ssh_protocol == NULL) return; ssh_protocol(buf, len, 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) { 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: - s_wrpkt_start(11, 16); - pktout.body[0] = (rows >> 24) & 0xFF; - pktout.body[1] = (rows >> 16) & 0xFF; - pktout.body[2] = (rows >> 8) & 0xFF; - pktout.body[3] = rows & 0xFF; - pktout.body[4] = (cols >> 24) & 0xFF; - pktout.body[5] = (cols >> 16) & 0xFF; - pktout.body[6] = (cols >> 8) & 0xFF; - pktout.body[7] = cols & 0xFF; - memset(pktout.body+8, 0, 8); - s_wrpkt(); + 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; } } /* - * (Send Telnet special codes) + * Send Telnet special codes. TS_EOF is useful for `plink', so you + * can send an EOF and collect resulting output (e.g. `plink + * hostname sort'). */ static void ssh_special (Telnet_Special code) { - /* do nothing */ + if (code == TS_EOF) { + 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 */ + } +} + +static Socket ssh_socket(void) { return s; } + +static int ssh_sendok(void) { return ssh_send_ok; } + +static int ssh_ldisc(int option) { + if (option == LD_ECHO) return ssh_echoing; + if (option == LD_EDIT) return ssh_editing; + return FALSE; } Backend ssh_backend = { ssh_init, - ssh_msg, ssh_send, ssh_size, - ssh_special + ssh_special, + ssh_socket, + ssh_sendok, + ssh_ldisc, + 22 };