X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/3effbcf21a3e3af6994d9ab112db9ce7ba44bbce..c99deca40eecb33ffe93e2290337833afb9493aa:/ssh.c diff --git a/ssh.c b/ssh.c index eee792b7..f39894ae 100644 --- a/ssh.c +++ b/ssh.c @@ -196,6 +196,7 @@ static const char *const ssh2_disconnect_reasons[] = { #define BUG_SSH2_PK_SESSIONID 128 #define BUG_SSH2_MAXPKT 256 #define BUG_CHOKES_ON_SSH2_IGNORE 512 +#define BUG_CHOKES_ON_WINADJ 1024 /* * Codes for terminal modes. @@ -517,9 +518,6 @@ static void ssh_channel_destroy(struct ssh_channel *c); #define OUR_V2_MAXPKT 0x4000UL #define OUR_V2_PACKETLIMIT 0x9000UL -/* Maximum length of passwords/passphrases (arbitrary) */ -#define SSH_MAX_PASSWORD_LEN 100 - const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; const static struct ssh_mac *macs[] = { @@ -561,7 +559,15 @@ enum { /* channel types */ CHAN_X11, CHAN_AGENT, CHAN_SOCKDATA, - CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */ + CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */ + /* + * CHAN_ZOMBIE is used to indicate a channel for which we've + * already destroyed the local data source: for instance, if a + * forwarded port experiences a socket error on the local side, we + * immediately destroy its local socket and turn the SSH channel + * into CHAN_ZOMBIE. + */ + CHAN_ZOMBIE }; /* @@ -2575,6 +2581,15 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE; logevent("We believe remote version has SSH-2 ignore bug"); } + + if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) { + /* + * Servers that don't support our winadj request for one + * reason or another. Currently, none detected automatically. + */ + ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ; + logevent("We believe remote version has winadj bug"); + } } /* @@ -3526,8 +3541,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->cur_prompt = new_prompts(ssh->frontend); s->cur_prompt->to_server = TRUE; s->cur_prompt->name = dupstr("SSH login name"); - /* 512 is an arbitrary upper limit on username size */ - add_prompt(s->cur_prompt, dupstr("login as: "), TRUE, 512); + add_prompt(s->cur_prompt, dupstr("login as: "), TRUE); ret = get_userpass_input(s->cur_prompt, NULL, 0); while (ret < 0) { ssh->send_ok = 1; @@ -3573,7 +3587,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, * Load the public half of any configured keyfile for later use. */ s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); - if (!filename_is_null(*s->keyfile)) { + if (!filename_is_null(s->keyfile)) { int keytype; logeventf(ssh, "Reading private key file \"%.150s\"", filename_to_str(s->keyfile)); @@ -3820,8 +3834,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->cur_prompt->name = dupstr("SSH key passphrase"); add_prompt(s->cur_prompt, dupprintf("Passphrase for key \"%.100s\": ", - s->publickey_comment), - FALSE, SSH_MAX_PASSWORD_LEN); + s->publickey_comment), FALSE); ret = get_userpass_input(s->cur_prompt, NULL, 0); while (ret < 0) { ssh->send_ok = 1; @@ -3846,7 +3859,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ret = loadrsakey(s->keyfile, &s->key, passphrase, &error); if (passphrase) { - memset(passphrase, 0, strlen(passphrase)); + smemclr(passphrase, strlen(passphrase)); sfree(passphrase); } if (ret == 1) { @@ -3976,7 +3989,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, (*instr_suf) ? "\n" : "", instr_suf); s->cur_prompt->instr_reqd = TRUE; - add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN); + add_prompt(s->cur_prompt, prompt, FALSE); sfree(instr_suf); } } @@ -4019,7 +4032,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, (*instr_suf) ? "\n" : "", instr_suf); s->cur_prompt->instr_reqd = TRUE; - add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN); + add_prompt(s->cur_prompt, prompt, FALSE); sfree(instr_suf); } } @@ -4032,7 +4045,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->cur_prompt->name = dupstr("SSH password"); add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ", ssh->username, ssh->savedhost), - FALSE, SSH_MAX_PASSWORD_LEN); + FALSE); } /* @@ -4255,6 +4268,35 @@ void sshfwd_write_eof(struct ssh_channel *c) ssh_channel_try_eof(c); } +void sshfwd_unclean_close(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + struct Packet *pktout; + + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (!(c->closes & CLOSES_SENT_CLOSE)) { + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE; + } + + switch (c->type) { + case CHAN_X11: + x11_close(c->u.x11.s); + break; + case CHAN_SOCKDATA: + case CHAN_SOCKDATA_DORMANT: + pfd_close(c->u.pfd.s); + break; + } + c->type = CHAN_ZOMBIE; + + ssh2_channel_check_close(c); +} + int sshfwd_write(struct ssh_channel *c, char *buf, int len) { Ssh ssh = c->ssh; @@ -5746,6 +5788,12 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, break; } } + if (!ssh->hostkey) { + bombout(("Couldn't agree a host key algorithm (available: %s)", + str ? str : "(null)")); + crStop(0); + } + s->guessok = s->guessok && first_in_commasep_string(hostkey_algs[0]->name, str, len); ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */ @@ -6256,7 +6304,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, assert(ssh->csmac->len <= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace); - memset(keyspace, 0, sizeof(keyspace)); + smemclr(keyspace, sizeof(keyspace)); } logeventf(ssh, "Initialised %.200s client->server encryption", @@ -6322,7 +6370,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, assert(ssh->scmac->len <= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace); - memset(keyspace, 0, sizeof(keyspace)); + smemclr(keyspace, sizeof(keyspace)); } logeventf(ssh, "Initialised %.200s server->client encryption", ssh->sccipher->text_name); @@ -6556,9 +6604,10 @@ static void ssh2_set_window(struct ssh_channel *c, int newwin) /* * Never send WINDOW_ADJUST for a channel that the remote side has * already sent EOF on; there's no point, since it won't be - * sending any more data anyway. + * sending any more data anyway. Ditto if _we've_ already sent + * CLOSE. */ - if (c->closes & CLOSES_RCVD_EOF) + if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE)) return; /* @@ -6568,7 +6617,6 @@ static void ssh2_set_window(struct ssh_channel *c, int newwin) */ if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT) newwin = OUR_V2_MAXPKT; - /* * Only send a WINDOW_ADJUST if there's significantly more window @@ -6597,7 +6645,8 @@ static void ssh2_set_window(struct ssh_channel *c, int newwin) * unexpected CHANNEL_FAILUREs. */ if (newwin == c->v.v2.locmaxwin && - ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) { + ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] && + !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) { pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); ssh2_pkt_adduint32(pktout, c->remoteid); ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org"); @@ -6983,16 +7032,28 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) * the remote side is doing away with the entire channel. (If it * had wanted to send us EOF and continue receiving data from us, * it would have just sent CHANNEL_EOF.) - * - * For the moment, this policy applies to the main session channel - * only, because we have a convenient mechanism (ssh->send_ok) for - * ceasing to read from our local data source. Ideally I think - * we'd do this for auxiliary channels too, which would need an - * extra API call in the forwarding modules. */ - if (c->type == CHAN_MAINSESSION && !(c->closes & CLOSES_SENT_EOF)) { - sshfwd_write_eof(ssh->mainchan); - ssh->send_ok = 0; /* now stop trying to read from stdin */ + if (!(c->closes & CLOSES_SENT_EOF)) { + /* + * Make sure we don't read any more from whatever our local + * data source is for this channel. + */ + switch (c->type) { + case CHAN_MAINSESSION: + ssh->send_ok = 0; /* stop trying to read from stdin */ + break; + case CHAN_X11: + x11_override_throttle(c->u.x11.s, 1); + break; + case CHAN_SOCKDATA: + pfd_override_throttle(c->u.pfd.s, 1); + break; + } + + /* + * Send outgoing EOF. + */ + sshfwd_write_eof(c); } /* @@ -7451,6 +7512,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int siglen, retlen, len; char *q, *agentreq, *ret; int try_send; + int requested_x11; + int requested_agent; + int requested_tty; int num_env, env_left, env_ok; struct Packet *pktout; Filename *keyfile; @@ -7517,7 +7581,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * for later use. */ s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); - if (!filename_is_null(*s->keyfile)) { + if (!filename_is_null(s->keyfile)) { int keytype; logeventf(ssh, "Reading private key file \"%.150s\"", filename_to_str(s->keyfile)); @@ -7663,8 +7727,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->cur_prompt = new_prompts(ssh->frontend); s->cur_prompt->to_server = TRUE; s->cur_prompt->name = dupstr("SSH login name"); - /* 512 is an arbitrary limit :-( */ - add_prompt(s->cur_prompt, dupstr("login as: "), TRUE, 512); + add_prompt(s->cur_prompt, dupstr("login as: "), TRUE); ret = get_userpass_input(s->cur_prompt, NULL, 0); while (ret < 0) { ssh->send_ok = 1; @@ -8070,7 +8133,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, add_prompt(s->cur_prompt, dupprintf("Passphrase for key \"%.100s\": ", s->publickey_comment), - FALSE, SSH_MAX_PASSWORD_LEN); + FALSE); ret = get_userpass_input(s->cur_prompt, NULL, 0); while (ret < 0) { ssh->send_ok = 1; @@ -8102,7 +8165,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, key = ssh2_load_userkey(s->keyfile, passphrase, &error); if (passphrase) { /* burn the evidence */ - memset(passphrase, 0, strlen(passphrase)); + smemclr(passphrase, strlen(passphrase)); sfree(passphrase); } if (key == SSH2_WRONG_PASSPHRASE || key == NULL) { @@ -8450,7 +8513,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } add_prompt(s->cur_prompt, dupprintf("%.*s", prompt_len, prompt), - echo, SSH_MAX_PASSWORD_LEN); + echo); } if (name_len) { @@ -8518,6 +8581,13 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } ssh2_pkt_send_with_padding(ssh, s->pktout, 256); + /* + * Free the prompts structure from this iteration. + * If there's another, a new one will be allocated + * when we return to the top of this while loop. + */ + free_prompts(s->cur_prompt); + /* * Get the next packet in case it's another * INFO_REQUEST. @@ -8547,7 +8617,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ", ssh->username, ssh->savedhost), - FALSE, SSH_MAX_PASSWORD_LEN); + FALSE); ret = get_userpass_input(s->cur_prompt, NULL, 0); while (ret < 0) { @@ -8649,11 +8719,11 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ add_prompt(s->cur_prompt, dupstr("Current password (blank for previously entered password): "), - FALSE, SSH_MAX_PASSWORD_LEN); + FALSE); add_prompt(s->cur_prompt, dupstr("Enter new password: "), - FALSE, SSH_MAX_PASSWORD_LEN); + FALSE); add_prompt(s->cur_prompt, dupstr("Confirm new password: "), - FALSE, SSH_MAX_PASSWORD_LEN); + FALSE); /* * Loop until the user manages to enter the same @@ -8674,7 +8744,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ /* burn the evidence */ free_prompts(s->cur_prompt); - memset(s->password, 0, strlen(s->password)); + smemclr(s->password, strlen(s->password)); sfree(s->password); ssh_disconnect(ssh, NULL, "Unable to authenticate", SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER, @@ -8690,7 +8760,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * re-enter it if they louse up the new password.) */ if (s->cur_prompt->prompts[0]->result[0]) { - memset(s->password, 0, strlen(s->password)); + smemclr(s->password, strlen(s->password)); /* burn the evidence */ sfree(s->password); s->password = @@ -8757,7 +8827,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * We don't need the old password any more, in any * case. Burn the evidence. */ - memset(s->password, 0, strlen(s->password)); + smemclr(s->password, strlen(s->password)); sfree(s->password); } else { @@ -8932,6 +9002,17 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } /* + * Enable port forwardings. + */ + ssh_setup_portfwd(ssh, ssh->conf); + + /* + * Send the CHANNEL_REQUESTS for the main channel. We send them all + * and then start looking for responses, so it's important that the + * sending and receiving code below it is kept in sync. + */ + + /* * Potentially enable X11 forwarding. */ if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_x11_forward) && @@ -8956,26 +9037,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, end_log_omission(ssh, s->pktout); ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum); ssh2_pkt_send(ssh, s->pktout); - - crWaitUntilV(pktin); - - if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { - if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Unexpected response to X11 forwarding request:" - " packet type %d", pktin->type)); - crStopV; - } - logevent("X11 forwarding refused"); - } else { - logevent("X11 forwarding enabled"); - ssh->X11_fwd_enabled = TRUE; - } - } - - /* - * Enable port forwardings. - */ - ssh_setup_portfwd(ssh, ssh->conf); + s->requested_x11 = TRUE; + } else + s->requested_x11 = FALSE; /* * Potentially enable agent forwarding. @@ -8987,21 +9051,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com"); ssh2_pkt_addbool(s->pktout, 1); /* want reply */ ssh2_pkt_send(ssh, s->pktout); - - crWaitUntilV(pktin); - - if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { - if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Unexpected response to agent forwarding request:" - " packet type %d", pktin->type)); - crStopV; - } - logevent("Agent forwarding refused"); - } else { - logevent("Agent forwarding enabled"); - ssh->agentfwd_enabled = TRUE; - } - } + s->requested_agent = TRUE; + } else + s->requested_agent = FALSE; /* * Now allocate a pty for the session. @@ -9030,25 +9082,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */ ssh2_pkt_send(ssh, s->pktout); ssh->state = SSH_STATE_INTERMED; - - crWaitUntilV(pktin); - - if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { - if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Unexpected response to pty request:" - " packet type %d", pktin->type)); - crStopV; - } - c_write_str(ssh, "Server refused to allocate pty\r\n"); - ssh->editing = ssh->echoing = 1; - } else { - logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", - ssh->ospeed, ssh->ispeed); - ssh->got_pty = TRUE; - } - } else { - ssh->editing = ssh->echoing = 1; - } + s->requested_tty = TRUE; + } else + s->requested_tty = FALSE; /* * Send environment variables. @@ -9056,11 +9092,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * Simplest thing here is to send all the requests at once, and * then wait for a whole bunch of successes or failures. */ + s->num_env = 0; if (ssh->mainchan && !ssh->ncmode) { char *key, *val; - s->num_env = 0; - for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key); val != NULL; val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) { @@ -9074,39 +9109,96 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->num_env++; } - - if (s->num_env) { + if (s->num_env) logeventf(ssh, "Sent %d environment variables", s->num_env); + } - s->env_ok = 0; - s->env_left = s->num_env; + /* + * All CHANNEL_REQUESTs sent. Now collect up the replies. These + * must be in precisely the same order as the requests. + */ - while (s->env_left > 0) { - crWaitUntilV(pktin); + if (s->requested_x11) { + crWaitUntilV(pktin); - if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { - if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Unexpected response to environment request:" - " packet type %d", pktin->type)); - crStopV; - } - } else { - s->env_ok++; - } + if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Unexpected response to X11 forwarding request:" + " packet type %d", pktin->type)); + crStopV; + } + logevent("X11 forwarding refused"); + } else { + logevent("X11 forwarding enabled"); + ssh->X11_fwd_enabled = TRUE; + } + } + + if (s->requested_agent) { + crWaitUntilV(pktin); - s->env_left--; + if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Unexpected response to agent forwarding request:" + " packet type %d", pktin->type)); + crStopV; } + logevent("Agent forwarding refused"); + } else { + logevent("Agent forwarding enabled"); + ssh->agentfwd_enabled = TRUE; + } + } + + if (s->requested_tty) { + crWaitUntilV(pktin); - if (s->env_ok == s->num_env) { - logevent("All environment variables successfully set"); - } else if (s->env_ok == 0) { - logevent("All environment variables refused"); - c_write_str(ssh, "Server refused to set environment variables\r\n"); + if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Unexpected response to pty request:" + " packet type %d", pktin->type)); + crStopV; + } + c_write_str(ssh, "Server refused to allocate pty\r\n"); + ssh->editing = ssh->echoing = 1; + } else { + logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", + ssh->ospeed, ssh->ispeed); + ssh->got_pty = TRUE; + } + } else { + ssh->editing = ssh->echoing = 1; + } + + if (s->num_env) { + s->env_ok = 0; + s->env_left = s->num_env; + + while (s->env_left > 0) { + crWaitUntilV(pktin); + + if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Unexpected response to environment request:" + " packet type %d", pktin->type)); + crStopV; + } } else { - logeventf(ssh, "%d environment variables refused", - s->num_env - s->env_ok); - c_write_str(ssh, "Server refused to set all environment variables\r\n"); + s->env_ok++; } + + s->env_left--; + } + + if (s->env_ok == s->num_env) { + logevent("All environment variables successfully set"); + } else if (s->env_ok == 0) { + logevent("All environment variables refused"); + c_write_str(ssh, "Server refused to set environment variables\r\n"); + } else { + logeventf(ssh, "%d environment variables refused", + s->num_env - s->env_ok); + c_write_str(ssh, "Server refused to set all environment variables\r\n"); } } @@ -9987,6 +10079,12 @@ static void ssh_unthrottle(void *handle, int bufsize) } } } + + /* + * Now process any SSH connection data that was stashed in our + * queue while we were frozen. + */ + ssh_process_queued_incoming_data(ssh); } void ssh_send_port_open(void *channel, char *hostname, int port, char *org)