X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/033b4cef1e52d65786b00df47f57361b96ca4321..fe50e8140a2dbb3ba357a0ab777f34e07d568c23:/ssh.c diff --git a/ssh.c b/ssh.c index d327471c..c065f2f8 100644 --- a/ssh.c +++ b/ssh.c @@ -2,11 +2,17 @@ #include #include #include +#ifndef AUTO_WINSOCK +#ifdef WINSOCK_TWO +#include +#else #include +#endif +#endif #include "putty.h" +#include "tree234.h" #include "ssh.h" -#include "scp.h" #ifndef FALSE #define FALSE 0 @@ -16,44 +22,97 @@ #endif #define logevent(s) { logevent(s); \ - if (IS_SCP && (scp_flags & SCP_VERBOSE) != 0) \ + if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \ fprintf(stderr, "%s\n", s); } -#define SSH1_MSG_DISCONNECT 1 -#define SSH1_SMSG_PUBLIC_KEY 2 -#define SSH1_CMSG_SESSION_KEY 3 -#define SSH1_CMSG_USER 4 -#define SSH1_CMSG_AUTH_PASSWORD 9 -#define SSH1_CMSG_REQUEST_PTY 10 -#define SSH1_CMSG_WINDOW_SIZE 11 -#define SSH1_CMSG_EXEC_SHELL 12 -#define SSH1_CMSG_EXEC_CMD 13 -#define SSH1_SMSG_SUCCESS 14 -#define SSH1_SMSG_FAILURE 15 -#define SSH1_CMSG_STDIN_DATA 16 -#define SSH1_SMSG_STDOUT_DATA 17 -#define SSH1_SMSG_STDERR_DATA 18 -#define SSH1_CMSG_EOF 19 -#define SSH1_SMSG_EXIT_STATUS 20 -#define SSH1_CMSG_EXIT_CONFIRMATION 33 -#define SSH1_MSG_IGNORE 32 -#define SSH1_MSG_DEBUG 36 -#define SSH1_CMSG_AUTH_TIS 39 -#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 -#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 - -#define SSH1_AUTH_TIS 5 - -#define SSH2_MSG_DISCONNECT 1 -#define SSH2_MSG_IGNORE 2 -#define SSH2_MSG_UNIMPLEMENTED 3 -#define SSH2_MSG_DEBUG 4 -#define SSH2_MSG_SERVICE_REQUEST 5 -#define SSH2_MSG_SERVICE_ACCEPT 6 -#define SSH2_MSG_KEXINIT 20 -#define SSH2_MSG_NEWKEYS 21 -#define SSH2_MSG_KEXDH_INIT 30 -#define SSH2_MSG_KEXDH_REPLY 31 +#define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, closesocket(s), \ + s = INVALID_SOCKET, 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_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ +#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ +#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ +#define SSH1_MSG_IGNORE 32 /* 0x20 */ +#define SSH1_MSG_DEBUG 36 /* 0x24 */ +#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_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) | \ @@ -67,7 +126,7 @@ (cp)[2] = (unsigned char)((value) >> 8); \ (cp)[3] = (unsigned char)(value); } -enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR }; +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; @@ -86,54 +145,98 @@ enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR }; #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)) -extern struct ssh_cipher ssh_3des; -extern struct ssh_cipher ssh_3des_ssh2; -extern struct ssh_cipher ssh_des; -extern struct ssh_cipher ssh_blowfish; - -/* for ssh 2; we miss out single-DES because it isn't supported */ -struct ssh_cipher *ciphers[] = { &ssh_3des_ssh2, &ssh_blowfish }; +extern 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; -extern struct ssh_kex ssh_diffiehellman; -struct ssh_kex *kex_algs[] = { &ssh_diffiehellman }; +/* + * 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 }; -extern struct ssh_hostkey ssh_dss; -struct ssh_hostkey *hostkey_algs[] = { &ssh_dss }; +extern const struct ssh_kex ssh_diffiehellman; +const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman }; -extern struct ssh_mac ssh_sha1; +extern const struct ssh_hostkey ssh_dss; +const static struct ssh_hostkey *hostkey_algs[] = { &ssh_dss }; -SHA_State exhash; +extern const struct ssh_mac ssh_md5, ssh_sha1, ssh_sha1_buggy; static void nullmac_key(unsigned char *key) { } static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { } static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; } -struct ssh_mac ssh_mac_none = { +const static struct ssh_mac ssh_mac_none = { nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0 }; -struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none }; +const static struct ssh_mac *macs[] = { + &ssh_sha1, &ssh_md5, &ssh_mac_none }; +const static struct ssh_mac *buggymacs[] = { + &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none }; -struct ssh_compress ssh_comp_none = { +const static struct ssh_compress ssh_comp_none = { "none" }; -struct ssh_compress *compressions[] = { &ssh_comp_none }; +const static struct ssh_compress *compressions[] = { &ssh_comp_none }; + +/* + * 2-3-4 tree storing channels. + */ +struct ssh_channel { + unsigned remoteid, localid; + int type; + int closes; + union { + struct ssh_agent_channel { + unsigned char *message; + unsigned char msglen[4]; + int lensofar, totallen; + } a; + struct ssh2_data_channel { + unsigned char *outbuffer; + unsigned outbuflen, outbufsize; + unsigned remwindow, remmaxpkt; + } v2; + } u; +}; + +struct Packet { + long length; + int type; + unsigned char *data; + unsigned char *body; + long savedpos; + long maxlen; +}; + +static SHA_State exhash; static SOCKET s = INVALID_SOCKET; static unsigned char session_key[32]; -static struct ssh_cipher *cipher = NULL; -static struct ssh_cipher *cscipher = NULL; -static struct ssh_cipher *sccipher = NULL; -static struct ssh_mac *csmac = NULL; -static struct ssh_mac *scmac = NULL; -static struct ssh_compress *cscomp = NULL; -static struct ssh_compress *sccomp = NULL; -static struct ssh_kex *kex = NULL; -static struct ssh_hostkey *hostkey = NULL; -int scp_flags = 0; +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_hostkey *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 tree234 *ssh_channels; /* indexed by local id */ +static struct ssh_channel *mainchan; /* primary session channel */ static enum { SSH_STATE_BEFORE_SIZE, @@ -144,14 +247,55 @@ static enum { static int size_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 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 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 s_write (char *buf, int len) { while (len > 0) { int i = send (s, buf, len, 0); - if (IS_SCP) { - noise_ultralight(i); - if (i <= 0) - fatalbox("Lost connection while sending"); - } + noise_ultralight(i); + if (i <= 0) { + bombout(("Lost connection while sending")); + return; + } if (i > 0) len -= i, buf += i; } @@ -161,8 +305,7 @@ static int s_read (char *buf, int len) { int ret = 0; while (len > 0) { int i = recv (s, buf, len, 0); - if (IS_SCP) - noise_ultralight(i); + noise_ultralight(i); if (i > 0) len -= i, buf += i, ret += i; else @@ -172,35 +315,16 @@ static int s_read (char *buf, int len) { } static void c_write (char *buf, int len) { - if (IS_SCP) { - if (len > 0 && buf[len-1] == '\n') len--; - if (len > 0 && buf[len-1] == '\r') len--; - if (len > 0) { fwrite(buf, len, 1, stderr); fputc('\n', stderr); } + if ((flags & FLAG_STDERR)) { + int i; + for (i = 0; i < len; i++) + if (buf[i] != '\r') + fputc(buf[i], stderr); return; } - while (len--) - c_write1(*buf++); + from_backend(1, buf, len); } -struct Packet { - long length; - int type; - unsigned char *data; - unsigned char *body; - long savedpos; - long maxlen; -}; - -static struct Packet pktin = { 0, 0, NULL, NULL, 0 }; -static struct Packet pktout = { 0, 0, NULL, NULL, 0 }; - -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 int (*s_rdpkt)(unsigned char **data, int *datalen); - /* * Collect incoming data in the incoming packet buffer. * Decipher and verify the packet when it is completely read. @@ -211,10 +335,7 @@ static int (*s_rdpkt)(unsigned char **data, int *datalen); */ static int ssh1_rdpkt(unsigned char **data, int *datalen) { - static long len, pad, biglen, to_read; - static unsigned long realcrc, gotcrc; - static unsigned char *p; - static int i; + struct rdpkt1_state_tag *st = &rdpkt1_state; crBegin; @@ -223,66 +344,75 @@ next_packet: pktin.type = 0; pktin.length = 0; - for (i = len = 0; i < 4; i++) { + for (st->i = st->len = 0; st->i < 4; st->i++) { while ((*datalen) == 0) - crReturn(4-i); - len = (len << 8) + **data; + crReturn(4-st->i); + st->len = (st->len << 8) + **data; (*data)++, (*datalen)--; } #ifdef FWHACK - if (len == 0x52656d6f) { /* "Remo"te server has closed ... */ - len = 0x300; /* big enough to carry to end */ + if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */ + st->len = 0x300; /* big enough to carry to end */ } #endif - pad = 8 - (len % 8); - biglen = len + pad; - pktin.length = len - 5; + st->pad = 8 - (st->len % 8); + st->biglen = st->len + st->pad; + pktin.length = st->len - 5; - if (pktin.maxlen < biglen) { - pktin.maxlen = biglen; - pktin.data = (pktin.data == NULL ? malloc(biglen+APIEXTRA) : - realloc(pktin.data, biglen+APIEXTRA)); + if (pktin.maxlen < st->biglen) { + pktin.maxlen = st->biglen; + pktin.data = (pktin.data == NULL ? malloc(st->biglen+APIEXTRA) : + realloc(pktin.data, st->biglen+APIEXTRA)); if (!pktin.data) fatalbox("Out of memory"); } - to_read = biglen; - p = pktin.data; - while (to_read > 0) { - static int chunk; - chunk = to_read; + st->to_read = st->biglen; + st->p = pktin.data; + while (st->to_read > 0) { + st->chunk = st->to_read; while ((*datalen) == 0) - crReturn(to_read); - if (chunk > (*datalen)) - chunk = (*datalen); - memcpy(p, *data, chunk); - *data += chunk; - *datalen -= chunk; - p += chunk; - to_read -= chunk; + crReturn(st->to_read); + if (st->chunk > (*datalen)) + st->chunk = (*datalen); + memcpy(st->p, *data, st->chunk); + *data += st->chunk; + *datalen -= st->chunk; + st->p += st->chunk; + st->to_read -= st->chunk; } if (cipher) - cipher->decrypt(pktin.data, biglen); + 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 - pktin.type = pktin.data[pad]; - pktin.body = pktin.data + pad + 1; + pktin.type = pktin.data[st->pad]; + pktin.body = pktin.data + st->pad + 1; - realcrc = crc32(pktin.data, biglen-4); - gotcrc = GET_32BIT(pktin.data+biglen-4); - if (gotcrc != realcrc) { - fatalbox("Incorrect CRC received on packet"); + 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); } 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_TIS_CHALLENGE || + pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) { long strlen = GET_32BIT(pktin.body); - if (strlen + 4 != pktin.length) - fatalbox("Received data packet with bogus string length"); + if (strlen + 4 != pktin.length) { + bombout(("Received data packet with bogus string length")); + crReturn(0); + } } if (pktin.type == SSH1_MSG_DEBUG) { @@ -305,29 +435,24 @@ next_packet: static int ssh2_rdpkt(unsigned char **data, int *datalen) { - static long len, pad, payload, packetlen, maclen; - static int i; - static int cipherblk; - static unsigned long incoming_sequence = 0; + struct rdpkt2_state_tag *st = &rdpkt2_state; crBegin; next_packet: - pktin.type = 0; pktin.length = 0; - - if (cipher) - cipherblk = cipher->blksize; + if (sccipher) + st->cipherblk = sccipher->blksize; else - cipherblk = 8; - if (cipherblk < 8) - cipherblk = 8; - - if (pktin.maxlen < cipherblk) { - pktin.maxlen = cipherblk; - pktin.data = (pktin.data == NULL ? malloc(cipherblk+APIEXTRA) : - realloc(pktin.data, cipherblk+APIEXTRA)); + st->cipherblk = 8; + if (st->cipherblk < 8) + st->cipherblk = 8; + + if (pktin.maxlen < st->cipherblk) { + pktin.maxlen = st->cipherblk; + pktin.data = (pktin.data == NULL ? malloc(st->cipherblk+APIEXTRA) : + realloc(pktin.data, st->cipherblk+APIEXTRA)); if (!pktin.data) fatalbox("Out of memory"); } @@ -336,10 +461,10 @@ next_packet: * Acquire and decrypt the first block of the packet. This will * contain the length and padding details. */ - for (i = len = 0; i < cipherblk; i++) { + for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) { while ((*datalen) == 0) - crReturn(cipherblk-i); - pktin.data[i] = *(*data)++; + crReturn(st->cipherblk-st->i); + pktin.data[st->i] = *(*data)++; (*datalen)--; } #ifdef FWHACK @@ -347,43 +472,35 @@ next_packet: /* FIXME */ } #endif - debug(("Got initblk:")); - for (i = 0; i < cipherblk; i++) - debug((" %02x", (unsigned char)pktin.data[i])); - debug(("\r\n")); if (sccipher) - sccipher->decrypt(pktin.data, cipherblk); - debug(("Decrypted initblk:")); - for (i = 0; i < cipherblk; i++) - debug((" %02x", (unsigned char)pktin.data[i])); - debug(("\r\n")); + sccipher->decrypt(pktin.data, st->cipherblk); /* * Now get the length and padding figures. */ - len = GET_32BIT(pktin.data); - pad = pktin.data[4]; + st->len = GET_32BIT(pktin.data); + st->pad = pktin.data[4]; /* * This enables us to deduce the payload length. */ - payload = len - pad - 1; + st->payload = st->len - st->pad - 1; - pktin.length = payload + 5; + pktin.length = st->payload + 5; /* * So now we can work out the total packet length. */ - packetlen = len + 4; - maclen = scmac ? scmac->len : 0; + st->packetlen = st->len + 4; + st->maclen = scmac ? scmac->len : 0; /* * Adjust memory allocation if packet is too big. */ - if (pktin.maxlen < packetlen) { - pktin.maxlen = packetlen; - pktin.data = (pktin.data == NULL ? malloc(packetlen+APIEXTRA) : - realloc(pktin.data, packetlen+APIEXTRA)); + if (pktin.maxlen < st->packetlen+st->maclen) { + pktin.maxlen = st->packetlen+st->maclen; + pktin.data = (pktin.data == NULL ? malloc(pktin.maxlen+APIEXTRA) : + realloc(pktin.data, pktin.maxlen+APIEXTRA)); if (!pktin.data) fatalbox("Out of memory"); } @@ -391,34 +508,38 @@ next_packet: /* * Read and decrypt the remainder of the packet. */ - for (i = cipherblk; i < packetlen + maclen; i++) { + for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) { while ((*datalen) == 0) - crReturn(packetlen + maclen - i); - pktin.data[i] = *(*data)++; + crReturn(st->packetlen + st->maclen - st->i); + pktin.data[st->i] = *(*data)++; (*datalen)--; } /* Decrypt everything _except_ the MAC. */ if (sccipher) - sccipher->decrypt(pktin.data + cipherblk, packetlen - cipherblk); + sccipher->decrypt(pktin.data + st->cipherblk, + st->packetlen - st->cipherblk); - debug(("Got packet len=%d pad=%d\r\n", len, pad)); - for (i = 0; i < packetlen; i++) - debug((" %02x", (unsigned char)pktin.data[i])); +#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, len+4, incoming_sequence)) - fatalbox("Incorrect MAC received on packet"); - incoming_sequence++; /* whether or not we MACed */ + if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) { + bombout(("Incorrect MAC received on packet")); + crReturn(0); + } + st->incoming_sequence++; /* whether or not we MACed */ pktin.savedpos = 6; pktin.type = pktin.data[5]; - /* - * FIXME: handle IGNORE and DEBUG messages. - */ + if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG) + goto next_packet; /* FIXME: print DEBUG message */ crFinish(0); } @@ -478,6 +599,12 @@ static void s_wrpkt(void) { PUT_32BIT(pktout.data+biglen, crc); PUT_32BIT(pktout.data, len); +#if 0 + debug(("Sending packet len=%d\r\n", biglen+4)); + for (i = 0; i < biglen+4; i++) + debug((" %02x", (unsigned char)pktout.data[i])); + debug(("\r\n")); +#endif if (cipher) cipher->encrypt(pktout.data+4, biglen); @@ -494,6 +621,7 @@ static void send_packet(int pkttype, ...) unsigned char *p, *argp, argchar; unsigned long argint; int pktlen, argtype, arglen; + Bignum bn; pktlen = 0; va_start(args, pkttype); @@ -517,6 +645,10 @@ static void send_packet(int pkttype, ...) arglen = strlen(argp); pktlen += 4 + arglen; break; + case PKT_BIGNUM: + bn = va_arg(args, Bignum); + pktlen += ssh1_bignum_length(bn); + break; default: assert(0); } @@ -552,6 +684,10 @@ static void send_packet(int pkttype, ...) 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); @@ -582,6 +718,7 @@ static char *connect_to_host(char *host, int port, char **realhost) if (port < 0) port = 22; /* default ssh port */ + savedport = port; #ifdef FWHACK FWhost = host; @@ -682,18 +819,187 @@ static int ssh_versioncmp(char *a, char *b) { * state. */ #include -void sha_string(SHA_State *s, void *str, int len) { +static void sha_string(SHA_State *s, void *str, int len) { unsigned char lenblk[4]; -static FILE *fp; PUT_32BIT(lenblk, len); -if (!fp) fp = fopen("h:\\statham\\windows\\putty\\data","wb"); -fwrite(lenblk, 4, 1, fp); SHA_Bytes(s, lenblk, 4); -fwrite(str, len, 1, fp); -fflush(fp); SHA_Bytes(s, str, len); } +/* + * SSH2 packet construction functions. + */ +static void ssh2_pkt_adddata(void *data, int len) { + pktout.length += len; + if (pktout.maxlen < pktout.length) { + pktout.maxlen = pktout.length + 256; + pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) : + realloc(pktout.data, pktout.maxlen+APIEXTRA)); + if (!pktout.data) + fatalbox("Out of memory"); + } + 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 = malloc(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); + free(p); +} +static void ssh2_pkt_send(void) { + int cipherblk, maclen, padding, i; + static unsigned long outgoing_sequence = 0; + + /* + * 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; + 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); + maclen = csmac ? csmac->len : 0; + + s_write(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")); + free(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); + free(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]); + } + return b; +} + static int do_ssh_init(void) { char c, *vsp; char version[10]; @@ -734,12 +1040,18 @@ static int do_ssh_init(void) { break; } + rdpkt2_state.incoming_sequence = 0; + *vsp = 0; sprintf(vlog, "Server version: %s", vstring); vlog[strcspn(vlog, "\r\n")] = '\0'; logevent(vlog); - if (ssh_versioncmp(version, "1.99") >= 0) { + /* + * 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. */ @@ -756,6 +1068,7 @@ static int do_ssh_init(void) { logevent("Using SSH protocol version 2"); s_write(vstring, strlen(vstring)); ssh_protocol = ssh2_protocol; + ssh_version = 2; s_rdpkt = ssh2_rdpkt; } else { /* @@ -769,8 +1082,10 @@ static int do_ssh_init(void) { logevent("Using SSH protocol version 1"); s_write(vstring, strlen(vstring)); ssh_protocol = ssh1_protocol; + ssh_version = 1; s_rdpkt = ssh1_rdpkt; } + ssh_send_ok = 0; return 1; } @@ -780,44 +1095,42 @@ static int do_ssh_init(void) { static int do_ssh1_login(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; 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) - fatalbox("Public key packet not received"); + 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); - j = makekey(pktin.body+8+i, &hostkey, &keystr2); + i = makekey(pktin.body+8, &servkey, &keystr1, 0); + j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0); /* - * Hash the host key and print the hash in the log box. Just as - * a last resort in case the registry's host key checking is - * compromised, we'll allow the user some ability to verify - * host keys by eye. + * Log the host key fingerprint. */ - MD5Init(&md5c); - MD5Update(&md5c, keystr2, hostkey.bytes); - MD5Final(session_id, &md5c); { char logmsg[80]; - int i; - logevent("Host key MD5 is:"); + logevent("Host key fingerprint is:"); strcpy(logmsg, " "); - for (i = 0; i < 16; i++) - sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]); + hostkey.comment = NULL; + rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg), + &hostkey); logevent(logmsg); } @@ -847,11 +1160,13 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) * First format the key into a string. */ int len = rsastr_len(&hostkey); + char fingerprint[100]; char *keystr = malloc(len); if (!keystr) fatalbox("Out of memory"); rsastr_fmt(keystr, &hostkey); - verify_ssh_host_key(savedhost, keystr); + rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); + verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint); free(keystr); } @@ -896,25 +1211,27 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) free(rsabuf); - cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish : + 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) - fatalbox("Encryption not successfully enabled"); + if (pktin.type != SSH1_SMSG_SUCCESS) { + bombout(("Encryption not successfully enabled")); + crReturn(0); + } logevent("Successfully started encryption"); fflush(stdout); { - static char username[100]; static int pos = 0; static char c; - if (!IS_SCP && !*cfg.username) { + 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++) { @@ -953,9 +1270,9 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) char stuff[200]; strncpy(username, cfg.username, 99); username[99] = '\0'; - if (!IS_SCP) { + if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { sprintf(stuff, "Sent username \"%s\".\r\n", username); - c_write(stuff, strlen(stuff)); + c_write(stuff, strlen(stuff)); } } @@ -969,99 +1286,319 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt) 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 - * exchange if we're doing TIS authentication. + * or CryptoCard exchange if we're doing TIS or CryptoCard + * authentication. */ pwpkt_type = SSH1_CMSG_AUTH_PASSWORD; - - if (IS_SCP) { - char prompt[200]; - sprintf(prompt, "%s@%s's password: ", cfg.username, savedhost); - if (!ssh_get_password(prompt, password, sizeof(password))) { - /* - * get_password failed to get a password (for - * example because one was supplied on the command - * line which has already failed to work). - * Terminate. - */ - logevent("No more passwords to try"); - ssh_state = SSH_STATE_CLOSED; - crReturn(1); - } - } else { + 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 = malloc(4 + len); + PUT_32BIT(agentreq, len); + q = agentreq + 4; + *q++ = SSH_AGENTC_RSA_CHALLENGE; + PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus)); + q += 4; + q += ssh1_write_bignum(q, key.exponent); + q += ssh1_write_bignum(q, key.modulus); + q += ssh1_write_bignum(q, challenge); + memcpy(q, session_id, 16); q += 16; + PUT_32BIT(q, 1); /* response format */ + agent_query(agentreq, len+4, &ret, &retlen); + free(agentreq); + if (ret) { + if (ret[4] == SSH_AGENT_RSA_RESPONSE) { + logevent("Sending Pageant's response"); + send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE, + PKT_DATA, ret+5, 16, PKT_END); + free(ret); + crWaitUntil(ispkt); + if (pktin.type == SSH1_SMSG_SUCCESS) { + logevent("Pageant's response accepted"); + 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"); + free(ret); + } + } else { + logevent("No reply received from Pageant"); + } + } + freebn(key.exponent); + freebn(key.modulus); + freebn(challenge); + if (authed) + break; + } + } + if (authed) + break; + } + if (*cfg.keyfile && !tried_publickey) + pwpkt_type = SSH1_CMSG_AUTH_RSA; 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 (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) - c_write("password: ", 10); + 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); + free(comment); + } - pos = 0; - while (pos >= 0) { - crWaitUntil(!ispkt); - while (inlen--) switch (c = *in++) { - case 10: case 13: - password[pos] = 0; - pos = -1; - break; - case 8: case 127: - if (pos > 0) - pos--; - break; - case 21: case 27: - pos = 0; - break; - case 3: case 4: - random_save_seed(); - exit(0); - break; - default: - if (((c >= ' ' && c <= '~') || - ((unsigned char)c >= 160)) && pos < 40) - password[pos++] = c; - break; - } - } - c_write("\r\n", 2); + 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); + } - send_packet(pwpkt_type, PKT_STR, password, PKT_END); + 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) { - c_write("Access denied\r\n", 15); + 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) { - fatalbox("Strange packet received, type %d", pktin.type); + bombout(("Strange packet received, type %d", pktin.type)); + crReturn(0); } } @@ -1081,6 +1618,19 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { 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"); + } + if (!cfg.nopty) { send_packet(SSH1_CMSG_REQUEST_PTY, PKT_STR, cfg.termtype, @@ -1091,30 +1641,128 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { ssh_state = SSH_STATE_INTERMED; do { crReturnV; } while (!ispkt); if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) { - fatalbox("Protocol confusion"); + bombout(("Protocol confusion")); + crReturnV; } else if (pktin.type == SSH1_SMSG_FAILURE) { c_write("Server refused to allocate pty\r\n", 32); } logevent("Allocated pty"); } - send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END); + 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"); ssh_state = SSH_STATE_SESSION; if (size_needed) ssh_size(); + ssh_send_ok = 1; + ssh_channels = newtree234(ssh_channelcmp); + begin_session(); while (1) { crReturnV; if (ispkt) { if (pktin.type == SSH1_SMSG_STDOUT_DATA || pktin.type == SSH1_SMSG_STDERR_DATA) { long len = GET_32BIT(pktin.body); - c_write(pktin.body+4, len); + 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"); + } 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 = 1; + struct ssh_channel *c; + enum234 e; + for (c = first234(ssh_channels, &e); c; c = next234(&e)) { + if (c->localid > i) + break; /* found a free number */ + i = c->localid + 1; + } + c = malloc(sizeof(struct ssh_channel)); + c->remoteid = GET_32BIT(pktin.body); + c->localid = i; + c->closes = 0; + c->type = SSH1_SMSG_AGENT_OPEN; /* 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); + c->closes |= closetype; + if (c->closes == 3) { + del234(ssh_channels, c); + free(c); + } + } + } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) { + /* Data sent down one of our channels. */ + int i = GET_32BIT(pktin.body); + int len = GET_32BIT(pktin.body+4); + unsigned char *p = pktin.body+8; + struct ssh_channel *c; + c = find234(ssh_channels, &i, ssh_channelfind); + if (c) { + switch(c->type) { + case SSH1_SMSG_AGENT_OPEN: + /* Data for an agent message. Buffer it. */ + while (len > 0) { + if (c->u.a.lensofar < 4) { + int l = min(4 - c->u.a.lensofar, len); + memcpy(c->u.a.msglen + c->u.a.lensofar, p, l); + p += l; len -= l; c->u.a.lensofar += l; + } + if (c->u.a.lensofar == 4) { + c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen); + c->u.a.message = malloc(c->u.a.totallen); + memcpy(c->u.a.message, c->u.a.msglen, 4); + } + if (c->u.a.lensofar >= 4 && len > 0) { + int l = min(c->u.a.totallen - c->u.a.lensofar, len); + memcpy(c->u.a.message + c->u.a.lensofar, p, l); + p += l; len -= l; c->u.a.lensofar += l; + } + if (c->u.a.lensofar == c->u.a.totallen) { + void *reply, *sentreply; + int replylen; + agent_query(c->u.a.message, c->u.a.totallen, + &reply, &replylen); + if (reply) + sentreply = reply; + else { + /* Fake SSH_AGENT_FAILURE. */ + sentreply = "\0\0\0\1\5"; + replylen = 5; + } + send_packet(SSH1_MSG_CHANNEL_DATA, + PKT_INT, c->remoteid, + PKT_INT, replylen, + PKT_DATA, sentreply, replylen, + PKT_END); + if (reply) + free(reply); + free(c->u.a.message); + c->u.a.lensofar = 0; + } + } + break; + } + } } else if (pktin.type == SSH1_SMSG_SUCCESS) { /* may be from EXEC_SHELL on some servers */ } else if (pktin.type == SSH1_SMSG_FAILURE) { @@ -1123,7 +1771,8 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); } else { - fatalbox("Strange packet received: type %d", pktin.type); + bombout(("Strange packet received: type %d", pktin.type)); + crReturnV; } } else { send_packet(SSH1_CMSG_STDIN_DATA, @@ -1135,168 +1784,9 @@ static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) { } /* - * SSH2 packet construction functions. - */ -void ssh2_pkt_adddata(void *data, int len) { - pktout.length += len; - if (pktout.maxlen < pktout.length) { - pktout.maxlen = pktout.length + 256; - pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) : - realloc(pktout.data, pktout.maxlen+APIEXTRA)); - if (!pktout.data) - fatalbox("Out of memory"); - } - memcpy(pktout.data+pktout.length-len, data, len); -} -void ssh2_pkt_addbyte(unsigned char byte) { - ssh2_pkt_adddata(&byte, 1); -} -void ssh2_pkt_init(int pkt_type) { - pktout.length = 5; - ssh2_pkt_addbyte((unsigned char)pkt_type); -} -void ssh2_pkt_addbool(unsigned char value) { - ssh2_pkt_adddata(&value, 1); -} -void ssh2_pkt_adduint32(unsigned long value) { - unsigned char x[4]; - PUT_32BIT(x, value); - ssh2_pkt_adddata(x, 4); -} -void ssh2_pkt_addstring_start(void) { - ssh2_pkt_adduint32(0); - pktout.savedpos = pktout.length; -} -void ssh2_pkt_addstring_str(char *data) { - ssh2_pkt_adddata(data, strlen(data)); - PUT_32BIT(pktout.data + pktout.savedpos - 4, - pktout.length - pktout.savedpos); -} -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); -} -void ssh2_pkt_addstring(char *data) { - ssh2_pkt_addstring_start(); - ssh2_pkt_addstring_str(data); -} -char *ssh2_mpint_fmt(Bignum b, int *len) { - unsigned char *p; - int i, n = b[0]; - p = malloc(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; -} -void ssh2_pkt_addmp(Bignum b) { - unsigned char *p; - int len; - p = ssh2_mpint_fmt(b, &len); - ssh2_pkt_addstring_start(); - ssh2_pkt_addstring_data(p, len); - free(p); -} -void ssh2_pkt_send(void) { - int cipherblk, maclen, padding, i; - static unsigned long outgoing_sequence = 0; - - /* - * 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; - 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 (cscipher) - cscipher->encrypt(pktout.data, pktout.length + padding); - maclen = csmac ? csmac->len : 0; -#if 0 - debug(("Sending packet len=%d\r\n", pktout.length+padding+maclen)); - for (i = 0; i < pktout.length+padding+maclen; i++) - debug((" %02x", (unsigned char)pktout.data[i])); - debug(("\r\n")); -#endif - s_write(pktout.data, pktout.length + padding + maclen); -} - -void sha_mpint(SHA_State *s, Bignum b) { - unsigned char *p; - int len; - p = ssh2_mpint_fmt(b, &len); - sha_string(s, p, len); - free(p); -} - -/* - * SSH2 packet decode functions. - */ -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; -} -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) - fatalbox("internal error: Can't handle negative mpints"); - b = newbn((length+1)/2); - for (i = 0; i < length; i++) { - j = length - 1 - i; - if (j & 1) - b[j/2+1] |= ((unsigned char)p[i]) << 8; - else - b[j/2+1] |= ((unsigned char)p[i]); - } - return b; -} - -void bndebug(char *string, Bignum b) { - unsigned char *p; - int i, len; - p = ssh2_mpint_fmt(b, &len); - debug(("%s", string)); - for (i = 0; i < len; i++) - debug((" %02x", p[i])); - debug(("\r\n")); - free(p); -} - -/* * Utility routine for decoding comma-separated strings in KEXINIT. */ -int in_commasep_string(char *needle, char *haystack, int haylen) { +static int in_commasep_string(char *needle, char *haystack, int haylen) { int needlen = strlen(needle); while (1) { /* @@ -1323,7 +1813,7 @@ int in_commasep_string(char *needle, char *haystack, int haylen) { /* * SSH2 key creation method. */ -void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) { +static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) { SHA_State s; /* First 20 bytes. */ SHA_Init(&s); @@ -1341,27 +1831,55 @@ void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) { } /* - * Handle the SSH2 key exchange phase. + * Handle the SSH2 transport layer. */ -static int do_ssh2_kex(unsigned char *in, int inlen, int ispkt) +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 struct ssh_cipher *cscipher_tobe = NULL; - static struct ssh_cipher *sccipher_tobe = NULL; - static struct ssh_mac *csmac_tobe = NULL; - static struct ssh_mac *scmac_tobe = NULL; - static struct ssh_compress *cscomp_tobe = NULL; - static struct ssh_compress *sccomp_tobe = NULL; - static char *hostkeydata, *sigdata; + 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 unsigned char exchange_hash[20]; static unsigned char keyspace[40]; + static const struct ssh_cipher *preferred_cipher; crBegin; + random_init(); + + /* + * Set up the preferred cipher. + */ + 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; + } /* + * Be prepared to work around the buggy MAC problem. + */ + if (cfg.buggymac) + maclist = buggymacs, nmacs = lenof(buggymacs); + else + maclist = macs, nmacs = lenof(macs); + + begin_key_exchange: + /* * Construct and send our key exchange packet. */ ssh2_pkt_init(SSH2_MSG_KEXINIT); @@ -1383,30 +1901,32 @@ static int do_ssh2_kex(unsigned char *in, int inlen, int ispkt) } /* List client->server encryption algorithms. */ ssh2_pkt_addstring_start(); - for (i = 0; i < lenof(ciphers); i++) { - ssh2_pkt_addstring_str(ciphers[i]->name); - if (i < lenof(ciphers)-1) + 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); i++) { - ssh2_pkt_addstring_str(ciphers[i]->name); - if (i < lenof(ciphers)-1) + 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 < lenof(macs); i++) { - ssh2_pkt_addstring_str(macs[i]->name); - if (i < lenof(macs)-1) + for (i = 0; i < nmacs; i++) { + ssh2_pkt_addstring_str(maclist[i]->name); + if (i < nmacs-1) ssh2_pkt_addstring_str(","); } /* List server->client MAC algorithms. */ ssh2_pkt_addstring_start(); - for (i = 0; i < lenof(macs); i++) { - ssh2_pkt_addstring_str(macs[i]->name); - if (i < lenof(macs)-1) + 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. */ @@ -1441,8 +1961,10 @@ static int do_ssh2_kex(unsigned char *in, int inlen, int ispkt) * Now examine the other side's KEXINIT to see what we're up * to. */ - if (pktin.type != SSH2_MSG_KEXINIT) - fatalbox("expected key exchange packet from server"); + 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 */ @@ -1461,30 +1983,32 @@ static int do_ssh2_kex(unsigned char *in, int inlen, int ispkt) } } ssh2_pkt_getstring(&str, &len); /* client->server cipher */ - for (i = 0; i < lenof(ciphers); i++) { - if (in_commasep_string(ciphers[i]->name, str, len)) { - cscipher_tobe = ciphers[i]; + 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); i++) { - if (in_commasep_string(ciphers[i]->name, str, len)) { - sccipher_tobe = ciphers[i]; + 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 < lenof(macs); i++) { - if (in_commasep_string(macs[i]->name, str, len)) { - csmac_tobe = macs[i]; + for (i = 0; i < nmacs; i++) { + if (in_commasep_string(maclist[i]->name, str, len)) { + csmac_tobe = maclist[i]; break; } } ssh2_pkt_getstring(&str, &len); /* server->client mac */ - for (i = 0; i < lenof(macs); i++) { - if (in_commasep_string(macs[i]->name, str, len)) { - scmac_tobe = macs[i]; + for (i = 0; i < nmacs; i++) { + if (in_commasep_string(maclist[i]->name, str, len)) { + scmac_tobe = maclist[i]; break; } } @@ -1502,41 +2026,34 @@ static int do_ssh2_kex(unsigned char *in, int inlen, int ispkt) break; } } - debug(("key exchange is %s\r\n", kex ? kex->name : NULL)); - debug(("host key alg is %s\r\n", hostkey ? hostkey->name : NULL)); - debug(("cscipher alg is %s\r\n", cscipher_tobe ? cscipher_tobe->name : NULL)); - debug(("sccipher alg is %s\r\n", sccipher_tobe ? sccipher_tobe->name : NULL)); - debug(("csmac alg is %s\r\n", csmac_tobe ? csmac_tobe->name : NULL)); - debug(("scmac alg is %s\r\n", scmac_tobe ? scmac_tobe->name : NULL)); - debug(("cscomp alg is %s\r\n", cscomp_tobe ? cscomp_tobe->name : NULL)); - debug(("sccomp alg is %s\r\n", sccomp_tobe ? sccomp_tobe->name : NULL)); /* * 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) - fatalbox("internal fault: chaos in SSH 2 transport layer"); + if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) { + bombout(("internal fault: chaos in SSH 2 transport layer")); + crReturn(0); + } /* * Now we begin the fun. Generate and send e for Diffie-Hellman. */ e = dh_create_e(); - bndebug("e=", e); ssh2_pkt_init(SSH2_MSG_KEXDH_INIT); ssh2_pkt_addmp(e); ssh2_pkt_send(); crWaitUntil(ispkt); - if (pktin.type != SSH2_MSG_KEXDH_REPLY) - fatalbox("expected key exchange packet from server"); + if (pktin.type != SSH2_MSG_KEXDH_REPLY) { + bombout(("expected key exchange packet from server")); + crReturn(0); + } ssh2_pkt_getstring(&hostkeydata, &hostkeylen); f = ssh2_pkt_getmp(); - bndebug("f=", f); ssh2_pkt_getstring(&sigdata, &siglen); K = dh_find_K(f); - bndebug("K=", K); sha_string(&exhash, hostkeydata, hostkeylen); sha_mpint(&exhash, e); @@ -1544,29 +2061,46 @@ static int do_ssh2_kex(unsigned char *in, int inlen, int ispkt) 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 + + hostkey->setkey(hostkeydata, hostkeylen); + if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) { + bombout(("Server failed host key check")); + crReturn(0); + } /* - * FIXME: verify host key. This bit will be moderately - * unpleasant, because of having to rewrite it to work - * alongside the old scheme. + * Expect SSH2_MSG_NEWKEYS from server. */ + crWaitUntil(ispkt); + if (pktin.type != SSH2_MSG_NEWKEYS) { + bombout(("expected new-keys packet from server")); + crReturn(0); + } /* - * FIXME: verify signature of exchange hash. + * Authenticate remote host: verify host key. (We've already + * checked the signature of the exchange hash.) */ + keystr = hostkey->fmtkey(); + fingerprint = hostkey->fingerprint(); + verify_ssh_host_key(savedhost, savedport, hostkey->keytype, + keystr, fingerprint); + logevent("Host key fingerprint is:"); + logevent(fingerprint); + free(fingerprint); + free(keystr); /* - * Send SSH2_MSG_NEWKEYS. Expect it from server. + * Send SSH2_MSG_NEWKEYS. */ ssh2_pkt_init(SSH2_MSG_NEWKEYS); ssh2_pkt_send(); - crWaitUntil(ispkt); - if (pktin.type != SSH2_MSG_NEWKEYS) - fatalbox("expected new-keys packet from server"); /* * Create and initialise session keys. @@ -1588,31 +2122,394 @@ static int do_ssh2_kex(unsigned char *in, int inlen, int ispkt) ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace); /* - * Now we're encrypting. Send a test packet (FIXME). + * 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. */ - crWaitUntil(!ispkt); - ssh2_pkt_init(SSH2_MSG_IGNORE); - ssh2_pkt_addstring("oo-er"); - ssh2_pkt_send(); - - crWaitUntil(0); + do { + crReturn(1); + } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)); + goto begin_key_exchange; crFinish(1); } -static void ssh2_protocol(unsigned char *in, int inlen, int 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; + crBegin; - random_init(); + /* + * 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 ((flags & FLAG_INTERACTIVE) && !*cfg.username) { + c_write("login as: ", 10); + ssh_send_ok = 1; + while (pos >= 0) { + crWaitUntilV(!ispkt); + while (inlen--) switch (c = *in++) { + case 10: case 13: + username[pos] = 0; + pos = -1; + break; + case 8: case 127: + if (pos > 0) { + c_write("\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 { + char stuff[200]; + strncpy(username, cfg.username, 99); + username[99] = '\0'; + if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { + sprintf(stuff, "Using username \"%s\".\r\n", username); + c_write(stuff, strlen(stuff)); + } + } + + 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); + } + + 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); + logevent("Authentication refused"); + } else + break; + } + + /* + * 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 = malloc(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->u.v2.remwindow = ssh2_pkt_getuint32(); + mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32(); + mainchan->u.v2.outbuffer = NULL; + mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0; + logevent("Opened channel for session"); + + /* + * 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(); + + do { + crWaitUntilV(ispkt); + if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { + /* FIXME: be able to handle other channels here */ + if (ssh2_pkt_getuint32() != mainchan->localid) + continue; /* wrong channel */ + mainchan->u.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); + } else { + logevent("Allocated pty"); + } + } + + /* + * 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) { + /* FIXME: be able to handle other channels here */ + if (ssh2_pkt_getuint32() != mainchan->localid) + continue; /* wrong channel */ + mainchan->u.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"); + } - while (!do_ssh2_kex(in, inlen, ispkt)) { + /* + * Transfer data! + */ + ssh_send_ok = 1; + begin_session(); + while (1) { + static int try_send; crReturnV; + try_send = FALSE; + if (ispkt) { + if (pktin.type == SSH2_MSG_CHANNEL_DATA || + pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { + char *data; + int length; + /* FIXME: be able to handle other channels here */ + if (ssh2_pkt_getuint32() != mainchan->localid) + continue; /* wrong channel */ + if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA && + ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR) + continue; /* extended but not stderr */ + ssh2_pkt_getstring(&data, &length); + if (data) { + from_backend(pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA, + data, length); + /* + * 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(mainchan->remoteid); + ssh2_pkt_adduint32(length); + ssh2_pkt_send(); + } + } else if (pktin.type == SSH2_MSG_DISCONNECT) { + ssh_state = SSH_STATE_CLOSED; + logevent("Received disconnect message"); + } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) { + continue; /* exit status et al; ignore (FIXME?) */ + } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) { + continue; /* remote sends EOF; ignore */ + } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) { + /* FIXME: be able to handle other channels here */ + if (ssh2_pkt_getuint32() != mainchan->localid) + continue; /* wrong channel */ + ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(mainchan->remoteid); + ssh2_pkt_send(); + /* FIXME: mark the channel as closed */ + if (1 /* FIXME: "all channels are closed" */) { + logevent("All channels closed. Disconnecting"); + ssh2_pkt_init(SSH2_MSG_DISCONNECT); + ssh2_pkt_send(); + ssh_state = SSH_STATE_CLOSED; + closesocket(s); + s = INVALID_SOCKET; + } + continue; /* remote sends close; ignore (FIXME) */ + } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) { + /* FIXME: be able to handle other channels here */ + if (ssh2_pkt_getuint32() != mainchan->localid) + continue; /* wrong channel */ + mainchan->u.v2.remwindow += ssh2_pkt_getuint32(); + try_send = TRUE; + } else { + bombout(("Strange packet received: type %d", pktin.type)); + crReturnV; + } + } else { + /* + * We have spare data. Add it to the channel buffer. + */ + if (mainchan->u.v2.outbufsize < + mainchan->u.v2.outbuflen + inlen) { + mainchan->u.v2.outbufsize = + mainchan->u.v2.outbuflen + inlen + 1024; + mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer, + mainchan->u.v2.outbufsize); + } + memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen, + in, inlen); + mainchan->u.v2.outbuflen += inlen; + try_send = TRUE; + } + if (try_send) { + /* + * Try to send data on the channel if we can. (FIXME: + * on _all_ channels.) + */ + while (mainchan->u.v2.remwindow > 0 && + mainchan->u.v2.outbuflen > 0) { + unsigned len = mainchan->u.v2.remwindow; + if (len > mainchan->u.v2.outbuflen) + len = mainchan->u.v2.outbuflen; + if (len > mainchan->u.v2.remmaxpkt) + len = mainchan->u.v2.remmaxpkt; + ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); + ssh2_pkt_adduint32(mainchan->remoteid); + ssh2_pkt_addstring_start(); + ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len); + ssh2_pkt_send(); + mainchan->u.v2.outbuflen -= len; + memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len, + mainchan->u.v2.outbuflen); + mainchan->u.v2.remwindow -= len; + } + } } crFinishV; } /* + * 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. Will arrange for WM_NETEVENT * messages to be passed to the specified window, whose window * procedure should then call telnet_msg(). @@ -1634,7 +2531,7 @@ static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) { if (!do_ssh_init()) return "Protocol initialisation error"; - if (WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR) + if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR) switch (WSAGetLastError()) { case WSAENETDOWN: return "Network is down"; default: return "WSAAsyncSelect(): unknown error"; @@ -1661,8 +2558,11 @@ static int ssh_msg (WPARAM wParam, LPARAM lParam) { if (s == INVALID_SOCKET) return 1; - if (WSAGETSELECTERROR(lParam) != 0) + if (WSAGETSELECTERROR(lParam) != 0) { + closesocket(s); + s = INVALID_SOCKET; return -WSAGETSELECTERROR(lParam); + } switch (WSAGETSELECTEVENT(lParam)) { case FD_READ: @@ -1670,8 +2570,11 @@ static int ssh_msg (WPARAM wParam, LPARAM lParam) { ret = recv(s, buf, sizeof(buf), 0); if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK) return 1; - if (ret < 0) /* any _other_ error */ + if (ret < 0) { /* any _other_ error */ + closesocket(s); + s = INVALID_SOCKET; return -10000-WSAGetLastError(); + } if (ret == 0) { s = INVALID_SOCKET; return 0; @@ -1718,190 +2621,44 @@ static void ssh_size(void) { } /* - * (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 */ -} - - -/* - * Read and decrypt one incoming SSH packet. - * (only used by pSCP) - */ -static void get_packet(void) -{ - unsigned char buf[4096], *p; - long to_read; - int len; - - assert(IS_SCP); - - p = NULL; - len = 0; - - while ((to_read = s_rdpkt(&p, &len)) > 0) { - if (to_read > sizeof(buf)) to_read = sizeof(buf); - len = s_read(buf, to_read); - if (len != to_read) { - closesocket(s); - s = INVALID_SOCKET; - return; - } - p = buf; - } - - assert(len == 0); -} - -/* - * Receive a block of data over the SSH link. Block until - * all data is available. Return nr of bytes read (0 if lost connection). - * (only used by pSCP) - */ -int ssh_scp_recv(unsigned char *buf, int len) -{ - static int pending_input_len = 0; - static unsigned char *pending_input_ptr; - int to_read = len; - - assert(IS_SCP); - - if (pending_input_len >= to_read) { - memcpy(buf, pending_input_ptr, to_read); - pending_input_ptr += to_read; - pending_input_len -= to_read; - return len; - } - - if (pending_input_len > 0) { - memcpy(buf, pending_input_ptr, pending_input_len); - buf += pending_input_len; - to_read -= pending_input_len; - pending_input_len = 0; - } - - if (s == INVALID_SOCKET) - return 0; - while (to_read > 0) { - get_packet(); - if (s == INVALID_SOCKET) - return 0; - if (pktin.type == SSH1_SMSG_STDOUT_DATA) { - int plen = GET_32BIT(pktin.body); - if (plen <= to_read) { - memcpy(buf, pktin.body + 4, plen); - buf += plen; - to_read -= plen; - } else { - memcpy(buf, pktin.body + 4, to_read); - pending_input_len = plen - to_read; - pending_input_ptr = pktin.body + 4 + to_read; - to_read = 0; - } - } else if (pktin.type == SSH1_SMSG_STDERR_DATA) { - int plen = GET_32BIT(pktin.body); - fwrite(pktin.body + 4, plen, 1, stderr); - } else if (pktin.type == SSH1_MSG_DISCONNECT) { - logevent("Received disconnect request"); - } else if (pktin.type == SSH1_SMSG_SUCCESS || - pktin.type == SSH1_SMSG_FAILURE) { - /* ignore */ - } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) { - char logbuf[100]; - sprintf(logbuf, "Remote exit status: %d", GET_32BIT(pktin.body)); - logevent(logbuf); - send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); - logevent("Closing connection"); - closesocket(s); - s = INVALID_SOCKET; - } else { - fatalbox("Strange packet received: type %d", pktin.type); - } + if (code == TS_EOF) { + if (ssh_version == 1) { + send_packet(SSH1_CMSG_EOF, PKT_END); + } else { + ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); + ssh2_pkt_adduint32(mainchan->remoteid); + ssh2_pkt_send(); + } + logevent("Sent EOF message"); + } else if (code == TS_PING) { + 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 */ } - - return len; } -/* - * Send a block of data over the SSH link. - * Block until all data is sent. - * (only used by pSCP) - */ -void ssh_scp_send(unsigned char *buf, int len) -{ - assert(IS_SCP); - if (s == INVALID_SOCKET) - return; - send_packet(SSH1_CMSG_STDIN_DATA, - PKT_INT, len, PKT_DATA, buf, len, PKT_END); -} - -/* - * Send an EOF notification to the server. - * (only used by pSCP) - */ -void ssh_scp_send_eof(void) -{ - assert(IS_SCP); - if (s == INVALID_SOCKET) - return; - send_packet(SSH1_CMSG_EOF, PKT_END); -} - -/* - * Set up the connection, login on the remote host and - * start execution of a command. - * Returns an error message, or NULL on success. - * (only used by pSCP) - */ -char *ssh_scp_init(char *host, int port, char *cmd, char **realhost) -{ - char buf[160], *p; - - assert(IS_SCP); - -#ifdef MSCRYPTOAPI - if (crypto_startup() == 0) - return "Microsoft high encryption pack not installed!"; -#endif - - p = connect_to_host(host, port, realhost); - if (p != NULL) - return p; - - random_init(); - - if (!do_ssh_init()) - return "Protocol initialisation error"; - - /* Exchange keys and login */ - do { - get_packet(); - if (s == INVALID_SOCKET) - return "Connection closed by remote host"; - } while (!do_ssh1_login(NULL, 0, 1)); - - if (ssh_state == SSH_STATE_CLOSED) { - closesocket(s); - s = INVALID_SOCKET; - return "Session initialisation error"; - } - - /* Execute command */ - sprintf(buf, "Sending command: %.100s", cmd); - logevent(buf); - send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END); - - return NULL; -} +static SOCKET ssh_socket(void) { return s; } +static int ssh_sendok(void) { return ssh_send_ok; } Backend ssh_backend = { ssh_init, ssh_msg, ssh_send, ssh_size, - ssh_special + ssh_special, + ssh_socket, + ssh_sendok, + 22 }; -