X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/a9e729265d681d997d78be8a002da76bf04e0e48..51e9d3c00a3471f284e89ec1f59f38ca25f10c5f:/ssh.c diff --git a/ssh.c b/ssh.c index fc20bec1..b5f34a52 100644 --- a/ssh.c +++ b/ssh.c @@ -256,18 +256,6 @@ static char *ssh2_pkt_type(int pkt_ctx, int type) #undef translate #undef translatec -#define GET_32BIT(cp) \ - (((unsigned long)(unsigned char)(cp)[0] << 24) | \ - ((unsigned long)(unsigned char)(cp)[1] << 16) | \ - ((unsigned long)(unsigned char)(cp)[2] << 8) | \ - ((unsigned long)(unsigned char)(cp)[3])) - -#define PUT_32BIT(cp, value) { \ - (cp)[0] = (unsigned char)((value) >> 24); \ - (cp)[1] = (unsigned char)((value) >> 16); \ - (cp)[2] = (unsigned char)((value) >> 8); \ - (cp)[3] = (unsigned char)(value); } - /* Enumeration values for fields in SSH-1 packets */ enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM, @@ -342,18 +330,18 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up * on a local data stream before we throttle the whole SSH - * connection (in SSH1 only). Throttling the whole connection is + * connection (in SSH-1 only). Throttling the whole connection is * pretty drastic so we set this high in the hope it won't * happen very often. * * - SSH_MAX_BACKLOG is the amount of backlog that must build up * on the SSH connection itself before we defensively throttle * _all_ local data streams. This is pretty drastic too (though - * thankfully unlikely in SSH2 since the window mechanism should + * thankfully unlikely in SSH-2 since the window mechanism should * ensure that the server never has any need to throttle its end * of the connection), so we set this high as well. * - * - OUR_V2_WINSIZE is the maximum window size we present on SSH2 + * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2 * channels. */ @@ -439,7 +427,7 @@ struct ssh_channel { /* True if we opened this channel but server hasn't confirmed. */ int halfopen; /* - * In SSH1, this value contains four bits: + * In SSH-1, this value contains four bits: * * 1 We have sent SSH1_MSG_CHANNEL_CLOSE. * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. @@ -475,11 +463,11 @@ struct ssh_channel { }; /* - * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH - * 2 use this structure in different ways, reflecting SSH 2's + * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2 + * use this structure in different ways, reflecting SSH-2's * altogether saner approach to port forwarding. * - * In SSH 1, you arrange a remote forwarding by sending the server + * In SSH-1, you arrange a remote forwarding by sending the server * the remote port number, and the local destination host:port. * When a connection comes in, the server sends you back that * host:port pair, and you connect to it. This is a ready-made @@ -491,15 +479,15 @@ struct ssh_channel { * host:port pairs we _are_ trying to forward to, and reject a * connection request from the server if it's not in the list. * - * In SSH 2, each side of the connection minds its own business and + * In SSH-2, each side of the connection minds its own business and * doesn't send unnecessary information to the other. You arrange a * remote forwarding by sending the server just the remote port * number. When a connection comes in, the server tells you which * of its ports was connected to; and _you_ have to remember what * local host:port pair went with that port number. * - * Hence, in SSH 1 this structure is indexed by destination - * host:port pair, whereas in SSH 2 it is indexed by source port. + * Hence, in SSH-1 this structure is indexed by destination + * host:port pair, whereas in SSH-2 it is indexed by source port. */ struct ssh_portfwd; /* forward declaration */ @@ -542,7 +530,7 @@ struct Packet { unsigned char *body; long savedpos; long maxlen; - long encrypted_len; /* for SSH2 total-size counting */ + long encrypted_len; /* for SSH-2 total-size counting */ /* * State associated with packet logging @@ -710,7 +698,7 @@ struct ssh_tag { struct rdpkt1_state_tag rdpkt1_state; struct rdpkt2_state_tag rdpkt2_state; - /* ssh1 and ssh2 use this for different things, but both use it */ + /* SSH-1 and SSH-2 use this for different things, but both use it */ int protocol_initial_phase_done; void (*protocol) (Ssh ssh, void *vin, int inlen, @@ -726,10 +714,23 @@ struct ssh_tag { Config cfg; /* - * Used to transfer data back from async agent callbacks. + * Used to transfer data back from async callbacks. */ void *agent_response; int agent_response_len; + int user_response; + + /* + * The SSH connection can be set as `frozen', meaning we are + * not currently accepting incoming data from the network. This + * is slightly more serious than setting the _socket_ as + * frozen, because we may already have had data passed to us + * from the network which we need to delay processing until + * after the freeze is lifted, so we also need a bufchain to + * store that data. + */ + int frozen; + bufchain queued_incoming_data; /* * Dispatch table for packet types that we may have to deal @@ -1545,7 +1546,7 @@ static void sha_uint32(SHA_State * s, unsigned i) } /* - * SSH2 packet construction functions. + * SSH-2 packet construction functions. */ static void ssh2_pkt_ensure(struct Packet *pkt, int length) { @@ -1637,7 +1638,7 @@ static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b) } /* - * Construct an SSH2 final-form packet: compress it, encrypt it, + * Construct an SSH-2 final-form packet: compress it, encrypt it, * put the MAC on it. Final packet, ready to be sent, is stored in * pkt->data. Total length is returned. */ @@ -1735,7 +1736,7 @@ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) */ /* - * Send an SSH2 packet immediately, without queuing or deferring. + * Send an SSH-2 packet immediately, without queuing or deferring. */ static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt) { @@ -1756,7 +1757,7 @@ static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt) } /* - * Defer an SSH2 packet. + * Defer an SSH-2 packet. */ static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt) { @@ -1774,7 +1775,7 @@ static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt) } /* - * Queue an SSH2 packet. + * Queue an SSH-2 packet. */ static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt) { @@ -1816,7 +1817,7 @@ static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt) /* * Send the whole deferred data block constructed by - * ssh2_pkt_defer() or SSH1's defer_packet(). + * ssh2_pkt_defer() or SSH-1's defer_packet(). * * The expected use of the defer mechanism is that you call * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If @@ -1847,7 +1848,7 @@ static void ssh_pkt_defersend(Ssh ssh) } /* - * Send all queued SSH2 packets. We send them by means of + * Send all queued SSH-2 packets. We send them by means of * ssh2_pkt_defer_noqueue(), in case they included a pair of * packets that needed to be lumped together. */ @@ -1888,7 +1889,7 @@ static void sha_mpint(SHA_State * s, Bignum b) } /* - * Packet decode functions for both SSH1 and SSH2. + * Packet decode functions for both SSH-1 and SSH-2. */ static unsigned long ssh_pkt_getuint32(struct Packet *pkt) { @@ -1979,7 +1980,7 @@ static Bignum ssh2_pkt_getmp(struct Packet *pkt) } /* - * Helper function to add an SSH2 signature blob to a packet. + * Helper function to add an SSH-2 signature blob to a packet. * Expects to be shown the public key blob as well as the signature * blob. Normally works just like ssh2_pkt_addstring, but will * fiddle with the signature packet if necessary for @@ -2075,7 +2076,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * sniffing. */ ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; - logevent("We believe remote version has SSH1 ignore bug"); + logevent("We believe remote version has SSH-1 ignore bug"); } if (ssh->cfg.sshbug_plainpw1 == FORCE_ON || @@ -2087,7 +2088,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * the password. */ ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD; - logevent("We believe remote version needs a plain SSH1 password"); + logevent("We believe remote version needs a plain SSH-1 password"); } if (ssh->cfg.sshbug_rsa1 == FORCE_ON || @@ -2099,7 +2100,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * an AUTH_RSA message. */ ssh->remote_bugs |= BUG_CHOKES_ON_RSA; - logevent("We believe remote version can't handle RSA authentication"); + logevent("We believe remote version can't handle SSH-1 RSA authentication"); } if (ssh->cfg.sshbug_hmac2 == FORCE_ON || @@ -2112,7 +2113,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * These versions have the HMAC bug. */ ssh->remote_bugs |= BUG_SSH2_HMAC; - logevent("We believe remote version has SSH2 HMAC bug"); + logevent("We believe remote version has SSH-2 HMAC bug"); } if (ssh->cfg.sshbug_derivekey2 == FORCE_ON || @@ -2125,7 +2126,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * generate the keys). */ ssh->remote_bugs |= BUG_SSH2_DERIVEKEY; - logevent("We believe remote version has SSH2 key-derivation bug"); + logevent("We believe remote version has SSH-2 key-derivation bug"); } if (ssh->cfg.sshbug_rsapad2 == FORCE_ON || @@ -2133,21 +2134,21 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) (wc_match("OpenSSH_2.[5-9]*", imp) || wc_match("OpenSSH_3.[0-2]*", imp)))) { /* - * These versions have the SSH2 RSA padding bug. + * These versions have the SSH-2 RSA padding bug. */ ssh->remote_bugs |= BUG_SSH2_RSA_PADDING; - logevent("We believe remote version has SSH2 RSA padding bug"); + logevent("We believe remote version has SSH-2 RSA padding bug"); } if (ssh->cfg.sshbug_pksessid2 == FORCE_ON || (ssh->cfg.sshbug_pksessid2 == AUTO && wc_match("OpenSSH_2.[0-2]*", imp))) { /* - * These versions have the SSH2 session-ID bug in + * These versions have the SSH-2 session-ID bug in * public-key authentication. */ ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID; - logevent("We believe remote version has SSH2 public-key-session-ID bug"); + logevent("We believe remote version has SSH-2 public-key-session-ID bug"); } if (ssh->cfg.sshbug_rekey2 == FORCE_ON || @@ -2157,10 +2158,10 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) wc_match("Sun_SSH_1.0", imp) || wc_match("Sun_SSH_1.0.1", imp)))) { /* - * These versions have the SSH2 rekey bug. + * These versions have the SSH-2 rekey bug. */ ssh->remote_bugs |= BUG_SSH2_REKEY; - logevent("We believe remote version has SSH2 rekey bug"); + logevent("We believe remote version has SSH-2 rekey bug"); } } @@ -2301,14 +2302,14 @@ static int do_ssh_init(Ssh ssh, unsigned char c) strcspn(s->vstring, "\015\012")); /* - * Initialise SSHv2 protocol. + * Initialise SSH-2 protocol. */ ssh->protocol = ssh2_protocol; ssh2_protocol_setup(ssh); ssh->s_rdpkt = ssh2_rdpkt; } else { /* - * Initialise SSHv1 protocol. + * Initialise SSH-1 protocol. */ ssh->protocol = ssh1_protocol; ssh1_protocol_setup(ssh); @@ -2331,6 +2332,50 @@ static int do_ssh_init(Ssh ssh, unsigned char c) crFinish(0); } +static void ssh_process_incoming_data(Ssh ssh, + unsigned char **data, int *datalen) +{ + struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen); + if (pktin) { + ssh->protocol(ssh, NULL, 0, pktin); + ssh_free_packet(pktin); + } +} + +static void ssh_queue_incoming_data(Ssh ssh, + unsigned char **data, int *datalen) +{ + bufchain_add(&ssh->queued_incoming_data, *data, *datalen); + *data += *datalen; + *datalen = 0; +} + +static void ssh_process_queued_incoming_data(Ssh ssh) +{ + void *vdata; + unsigned char *data; + int len, origlen; + + while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) { + bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len); + data = vdata; + origlen = len; + + while (!ssh->frozen && len > 0) + ssh_process_incoming_data(ssh, &data, &len); + + if (origlen > len) + bufchain_consume(&ssh->queued_incoming_data, origlen - len); + } +} + +static void ssh_set_frozen(Ssh ssh, int frozen) +{ + if (ssh->s) + sk_set_frozen(ssh->s, frozen); + ssh->frozen = frozen; +} + static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) { crBegin(ssh->ssh_gotdata_crstate); @@ -2360,13 +2405,19 @@ static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) */ if (datalen == 0) crReturnV; + + /* + * Process queued data if there is any. + */ + ssh_process_queued_incoming_data(ssh); + while (1) { while (datalen > 0) { - struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen); - if (pktin) { - ssh->protocol(ssh, NULL, 0, pktin); - ssh_free_packet(pktin); - } + if (ssh->frozen) + ssh_queue_incoming_data(ssh, &data, &datalen); + + ssh_process_incoming_data(ssh, &data, &datalen); + if (ssh->state == SSH_STATE_CLOSED) return; } @@ -2377,10 +2428,11 @@ static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) static int ssh_do_close(Ssh ssh, int notify_exit) { - int i, ret = 0; + int ret = 0; struct ssh_channel *c; ssh->state = SSH_STATE_CLOSED; + expire_timer_context(ssh); if (ssh->s) { sk_close(ssh->s); ssh->s = NULL; @@ -2390,11 +2442,11 @@ static int ssh_do_close(Ssh ssh, int notify_exit) ret = 1; } /* - * Now we must shut down any port and X forwardings going + * Now we must shut down any port- and X-forwarded channels going * through this connection. */ if (ssh->channels) { - for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { + while (NULL != (c = index234(ssh->channels, 0))) { switch (c->type) { case CHAN_X11: x11_close(c->u.x11.s); @@ -2403,12 +2455,26 @@ static int ssh_do_close(Ssh ssh, int notify_exit) pfd_close(c->u.pfd.s); break; } - del234(ssh->channels, c); + del234(ssh->channels, c); /* moving next one to index 0 */ if (ssh->version == 2) bufchain_clear(&c->v.v2.outbuffer); sfree(c); } } + /* + * Go through port-forwardings, and close any associated + * listening sockets. + */ + if (ssh->portfwds) { + struct ssh_portfwd *pf; + while (NULL != (pf = index234(ssh->portfwds, 0))) { + /* Dispose of any listening socket. */ + if (pf->local) + pfd_terminate(pf->local); + del234(ssh->portfwds, pf); /* moving next one to index 0 */ + free_portfwd(pf); + } + } return ret; } @@ -2440,6 +2506,9 @@ static int ssh_closing(Plug plug, const char *error_msg, int error_code, error_msg = "Server unexpectedly closed network connection"; } + if (need_notify) + notify_remote_exit(ssh->frontend); + if (error_msg) { /* A socket error has occurred. */ logevent(error_msg); @@ -2447,8 +2516,6 @@ static int ssh_closing(Plug plug, const char *error_msg, int error_code, } else { logevent("Server closed network connection"); } - if (need_notify) - notify_remote_exit(ssh->frontend); return 0; } @@ -2540,9 +2607,9 @@ static void ssh1_throttle(Ssh ssh, int adjust) ssh->v1_throttle_count += adjust; assert(ssh->v1_throttle_count >= 0); if (ssh->v1_throttle_count && !old_count) { - sk_set_frozen(ssh->s, 1); + ssh_set_frozen(ssh, 1); } else if (!ssh->v1_throttle_count && old_count) { - sk_set_frozen(ssh->s, 0); + ssh_set_frozen(ssh, 0); } } @@ -2583,7 +2650,7 @@ static void ssh_throttle_all(Ssh ssh, int enable, int bufsize) /* * Username and password input, abstracted off into routines - * reusable in several places - even between SSH1 and SSH2. + * reusable in several places - even between SSH-1 and SSH-2. */ /* Set up a username or password input loop on a given buffer. */ @@ -2666,6 +2733,24 @@ static void ssh_agent_callback(void *sshv, void *reply, int replylen) do_ssh2_authconn(ssh, NULL, -1, NULL); } +static void ssh_dialog_callback(void *sshv, int ret) +{ + Ssh ssh = (Ssh) sshv; + + ssh->user_response = ret; + + if (ssh->version == 1) + do_ssh1_login(ssh, NULL, -1, NULL); + else + do_ssh2_transport(ssh, NULL, -1, NULL); + + /* + * This may have unfrozen the SSH connection, so do a + * queued-data run. + */ + ssh_process_queued_incoming_data(ssh); +} + static void ssh_agentf_callback(void *cv, void *reply, int replylen) { struct ssh_channel *c = (struct ssh_channel *)cv; @@ -2727,6 +2812,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, Bignum challenge; char *commentp; int commentlen; + int dlgret; }; crState(do_ssh1_login_state); @@ -2744,14 +2830,14 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ptr = ssh_pkt_getdata(pktin, 8); if (!ptr) { - bombout(("SSH1 public key packet stopped before random cookie")); + bombout(("SSH-1 public key packet stopped before random cookie")); crStop(0); } memcpy(cookie, ptr, 8); if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) || !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) { - bombout(("Failed to read SSH1 public keys from public key packet")); + bombout(("Failed to read SSH-1 public keys from public key packet")); crStop(0); } @@ -2790,7 +2876,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, */ if (hostkey.bits > hostkey.bytes * 8 || servkey.bits > servkey.bytes * 8) { - bombout(("SSH1 public keys were badly formatted")); + bombout(("SSH-1 public keys were badly formatted")); crStop(0); } @@ -2814,10 +2900,31 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, fatalbox("Out of memory"); rsastr_fmt(keystr, &hostkey); rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); - verify_ssh_host_key(ssh->frontend, - ssh->savedhost, ssh->savedport, "rsa", keystr, - fingerprint); + + ssh_set_frozen(ssh, 1); + s->dlgret = verify_ssh_host_key(ssh->frontend, + ssh->savedhost, ssh->savedport, + "rsa", keystr, fingerprint, + ssh_dialog_callback, ssh); sfree(keystr); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user host key response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + + if (s->dlgret == 0) { + ssh->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } } for (i = 0; i < 32; i++) { @@ -2836,7 +2943,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey); } if (!ret) { - bombout(("SSH1 public key encryptions failed due to bad formatting")); + bombout(("SSH-1 public key encryptions failed due to bad formatting")); crStop(0); } @@ -2853,7 +2960,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, warn = 1; } else if (next_cipher == CIPHER_AES) { /* XXX Probably don't need to mention this. */ - logevent("AES not supported in SSH1, skipping"); + logevent("AES not supported in SSH-1, skipping"); } else { switch (next_cipher) { case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES; @@ -2869,7 +2976,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, } if (!cipher_chosen) { if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) - bombout(("Server violates SSH 1 protocol by not " + bombout(("Server violates SSH-1 protocol by not " "supporting 3DES encryption")); else /* shouldn't happen */ @@ -2879,9 +2986,26 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, /* Warn about chosen cipher if necessary. */ if (warn) { - sk_set_frozen(ssh->s, 1); - askalg(ssh->frontend, "cipher", cipher_string); - sk_set_frozen(ssh->s, 0); + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, "cipher", cipher_string, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } } } @@ -3042,7 +3166,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->p = s->response + 5; s->nkeys = GET_32BIT(s->p); s->p += 4; - logeventf(ssh, "Pageant has %d SSH1 keys", s->nkeys); + logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys); for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { logeventf(ssh, "Trying Pageant key #%d", s->keyi); if (s->publickey_blob && @@ -3202,6 +3326,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, bombout(("TIS challenge packet was badly formed")); crStop(0); } + c_write_str(ssh, "Using TIS authentication.\r\n"); logevent("Received TIS challenge"); if (challengelen > sizeof(s->prompt) - 1) challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ @@ -3235,6 +3360,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, bombout(("CryptoCard challenge packet was badly formed")); crStop(0); } + c_write_str(ssh, "Using CryptoCard authentication.\r\n"); logevent("Received CryptoCard challenge"); if (challengelen > sizeof(s->prompt) - 1) challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ @@ -3547,10 +3673,8 @@ void sshfwd_close(struct ssh_channel *c) { Ssh ssh = c->ssh; - if (ssh->state != SSH_STATE_SESSION) { - assert(ssh->state == SSH_STATE_CLOSED); + if (ssh->state == SSH_STATE_CLOSED) return; - } if (c && !c->closes) { /* @@ -3587,10 +3711,8 @@ int sshfwd_write(struct ssh_channel *c, char *buf, int len) { Ssh ssh = c->ssh; - if (ssh->state != SSH_STATE_SESSION) { - assert(ssh->state == SSH_STATE_CLOSED); + if (ssh->state == SSH_STATE_CLOSED) return 0; - } if (ssh->version == 1) { send_packet(ssh, SSH1_MSG_CHANNEL_DATA, @@ -3599,7 +3721,7 @@ int sshfwd_write(struct ssh_channel *c, char *buf, int len) PKT_INT, len, PKT_DATA, buf, len, PKTT_OTHER, PKT_END); /* - * In SSH1 we can return 0 here - implying that forwarded + * In SSH-1 we can return 0 here - implying that forwarded * connections are never individually throttled - because * the only circumstance that can cause throttling will be * the whole SSH connection backing up, in which case @@ -3616,10 +3738,8 @@ void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) { Ssh ssh = c->ssh; - if (ssh->state != SSH_STATE_SESSION) { - assert(ssh->state == SSH_STATE_CLOSED); + if (ssh->state == SSH_STATE_CLOSED) return; - } if (ssh->version == 1) { if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) { @@ -3771,13 +3891,13 @@ static void ssh_setup_portfwd(Ssh ssh, const Config *cfg) portfwd_strptr++; sports[n] = '\0'; if (ssh->version == 1 && type == 'R') { - logeventf(ssh, "SSH1 cannot handle remote source address " + logeventf(ssh, "SSH-1 cannot handle remote source address " "spec \"%s\"; ignoring", sports); } else strcpy(saddr, sports); n = 0; } - if (n < 255) sports[n++] = *portfwd_strptr++; + if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++; } sports[n] = 0; if (type != 'D') { @@ -3785,14 +3905,14 @@ static void ssh_setup_portfwd(Ssh ssh, const Config *cfg) portfwd_strptr++; n = 0; while (*portfwd_strptr && *portfwd_strptr != ':') { - if (n < 255) host[n++] = *portfwd_strptr++; + if (n < lenof(host)-1) host[n++] = *portfwd_strptr++; } host[n] = 0; if (*portfwd_strptr == ':') portfwd_strptr++; n = 0; while (*portfwd_strptr) { - if (n < 255) dports[n++] = *portfwd_strptr++; + if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++; } dports[n] = 0; portfwd_strptr++; @@ -3892,7 +4012,7 @@ static void ssh_setup_portfwd(Ssh ssh, const Config *cfg) if (ssh->version == 1) { /* * We cannot cancel listening ports on the - * server side in SSH1! There's no message + * server side in SSH-1! There's no message * to support it. Instead, we simply remove * the rportfwd record from the local end * so that any connections the server tries @@ -4481,12 +4601,14 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, /* * Start the shell or command. * - * Special case: if the first-choice command is an SSH2 + * Special case: if the first-choice command is an SSH-2 * subsystem (hence not usable here) and the second choice * exists, we fall straight back to that. */ { char *cmd = ssh->cfg.remote_cmd_ptr; + + if (!cmd) cmd = ssh->cfg.remote_cmd; if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) { cmd = ssh->cfg.remote_cmd_ptr2; @@ -4544,7 +4666,7 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, } /* - * Handle the top-level SSH2 protocol. + * Handle the top-level SSH-2 protocol. */ static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin) { @@ -4664,7 +4786,7 @@ static int first_in_commasep_string(char *needle, char *haystack, int haylen) /* - * SSH2 key creation method. + * SSH-2 key creation method. */ static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, unsigned char *sessid, char chr, @@ -4689,14 +4811,14 @@ static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, } /* - * Handle the SSH2 transport layer. + * Handle the SSH-2 transport layer. */ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, struct Packet *pktin) { unsigned char *in = (unsigned char *)vin; struct do_ssh2_transport_state { - int nbits, pbits, warn; + int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher; Bignum p, g, e, f, K; int kex_init_value, kex_reply_value; const struct ssh_mac **maclist; @@ -4718,6 +4840,9 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, const struct ssh_compress *preferred_comp; int got_session_id, activated_authconn; struct Packet *pktout; + int dlgret; + int guessok; + int ignorepkt; }; crState(do_ssh2_transport_state); @@ -4930,8 +5055,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * to. */ { - char *str; - int i, j, len, guessok; + char *str, *preferred; + int i, j, len; if (pktin->type != SSH2_MSG_KEXINIT) { bombout(("expected key exchange packet from server")); @@ -4945,25 +5070,23 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, s->scmac_tobe = NULL; s->cscomp_tobe = NULL; s->sccomp_tobe = NULL; + s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE; + pktin->savedpos += 16; /* skip garbage cookie */ ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */ - s->warn = 0; + + preferred = NULL; for (i = 0; i < s->n_preferred_kex; i++) { const struct ssh_kex *k = s->preferred_kex[i]; if (!k) { - s->warn = 1; - } else if (in_commasep_string(k->name, str, len)) { - ssh->kex = k; + s->warn_kex = TRUE; + } else { + if (!preferred) preferred = k->name; + if (in_commasep_string(k->name, str, len)) + ssh->kex = k; } - if (ssh->kex) { - if (s->warn) { - sk_set_frozen(ssh->s, 1); - askalg(ssh->frontend, "key-exchange algorithm", - ssh->kex->name); - sk_set_frozen(ssh->s, 0); - } + if (ssh->kex) break; - } } if (!ssh->kex) { bombout(("Couldn't agree a key exchange algorithm (available: %s)", @@ -4975,8 +5098,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * the first algorithm in our list, even if it's still the algorithm * we end up using. */ - guessok = - first_in_commasep_string(s->preferred_kex[0]->name, str, len); + s->guessok = first_in_commasep_string(preferred, str, len); ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */ for (i = 0; i < lenof(hostkey_algs); i++) { if (in_commasep_string(hostkey_algs[i]->name, str, len)) { @@ -4984,14 +5106,13 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, break; } } - guessok = guessok && + s->guessok = s->guessok && first_in_commasep_string(hostkey_algs[0]->name, str, len); ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */ - s->warn = 0; for (i = 0; i < s->n_preferred_ciphers; i++) { const struct ssh2_ciphers *c = s->preferred_ciphers[i]; if (!c) { - s->warn = 1; + s->warn_cscipher = TRUE; } else { for (j = 0; j < c->nciphers; j++) { if (in_commasep_string(c->list[j]->name, str, len)) { @@ -5000,15 +5121,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } } } - if (s->cscipher_tobe) { - if (s->warn) { - sk_set_frozen(ssh->s, 1); - askalg(ssh->frontend, "client-to-server cipher", - s->cscipher_tobe->name); - sk_set_frozen(ssh->s, 0); - } + if (s->cscipher_tobe) break; - } } if (!s->cscipher_tobe) { bombout(("Couldn't agree a client-to-server cipher (available: %s)", @@ -5017,11 +5131,10 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */ - s->warn = 0; for (i = 0; i < s->n_preferred_ciphers; i++) { const struct ssh2_ciphers *c = s->preferred_ciphers[i]; if (!c) { - s->warn = 1; + s->warn_sccipher = TRUE; } else { for (j = 0; j < c->nciphers; j++) { if (in_commasep_string(c->list[j]->name, str, len)) { @@ -5030,15 +5143,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } } } - if (s->sccipher_tobe) { - if (s->warn) { - sk_set_frozen(ssh->s, 1); - askalg(ssh->frontend, "server-to-client cipher", - s->sccipher_tobe->name); - sk_set_frozen(ssh->s, 0); - } + if (s->sccipher_tobe) break; - } } if (!s->sccipher_tobe) { bombout(("Couldn't agree a server-to-client cipher (available: %s)", @@ -5080,7 +5186,83 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } ssh_pkt_getstring(pktin, &str, &len); /* client->server language */ ssh_pkt_getstring(pktin, &str, &len); /* server->client language */ - if (ssh2_pkt_getbool(pktin) && !guessok) /* first_kex_packet_follows */ + s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok; + + if (s->warn_kex) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, "key-exchange algorithm", + ssh->kex->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } + } + + if (s->warn_cscipher) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, + "client-to-server cipher", + s->cscipher_tobe->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } + } + + if (s->warn_sccipher) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, + "server-to-client cipher", + s->sccipher_tobe->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } + } + + if (s->ignorepkt) /* first_kex_packet_follows */ crWaitUntil(pktin); /* Ignore packet */ } @@ -5204,11 +5386,29 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, */ s->keystr = ssh->hostkey->fmtkey(s->hkey); s->fingerprint = ssh->hostkey->fingerprint(s->hkey); - sk_set_frozen(ssh->s, 1); - verify_ssh_host_key(ssh->frontend, - ssh->savedhost, ssh->savedport, ssh->hostkey->keytype, - s->keystr, s->fingerprint); - sk_set_frozen(ssh->s, 0); + ssh_set_frozen(ssh, 1); + s->dlgret = verify_ssh_host_key(ssh->frontend, + ssh->savedhost, ssh->savedport, + ssh->hostkey->keytype, s->keystr, + s->fingerprint, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user host key response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } if (!s->got_session_id) { /* don't bother logging this in rekeys */ logevent("Host key fingerprint is:"); logevent(s->fingerprint); @@ -5424,7 +5624,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } /* - * Add data to an SSH2 channel output buffer. + * Add data to an SSH-2 channel output buffer. */ static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) @@ -5433,7 +5633,7 @@ static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, } /* - * Attempt to send data on an SSH2 channel. + * Attempt to send data on an SSH-2 channel. */ static int ssh2_try_send(struct ssh_channel *c) { @@ -5466,8 +5666,34 @@ static int ssh2_try_send(struct ssh_channel *c) return bufchain_size(&c->v.v2.outbuffer); } +static void ssh2_try_send_and_unthrottle(struct ssh_channel *c) +{ + int bufsize; + if (c->closes) + return; /* don't send on closing channels */ + bufsize = ssh2_try_send(c); + if (bufsize == 0) { + switch (c->type) { + case CHAN_MAINSESSION: + /* stdin need not receive an unthrottle + * notification since it will be polled */ + break; + case CHAN_X11: + x11_unthrottle(c->u.x11.s); + break; + case CHAN_AGENT: + /* agent sockets are request/response and need no + * buffer management */ + break; + case CHAN_SOCKDATA: + pfd_unthrottle(c->u.pfd.s); + break; + } + } +} + /* - * Potentially enlarge the window on an SSH2 channel. + * Potentially enlarge the window on an SSH-2 channel. */ static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) { @@ -5504,8 +5730,10 @@ static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) unsigned i = ssh_pkt_getuint32(pktin); struct ssh_channel *c; c = find234(ssh->channels, &i, ssh_channelfind); - if (c && !c->closes) + if (c && !c->closes) { c->v.v2.remwindow += ssh_pkt_getuint32(pktin); + ssh2_try_send_and_unthrottle(c); + } } static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) @@ -5664,7 +5892,7 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) /* * We used to send SSH_MSG_DISCONNECT here, * because I'd believed that _every_ conforming - * SSH2 connection had to end with a disconnect + * SSH-2 connection had to end with a disconnect * being sent by at least one side; apparently * I was wrong and it's perfectly OK to * unceremoniously slam the connection shut @@ -6027,7 +6255,7 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) } /* - * Handle the SSH2 userauth and connection layers. + * Handle the SSH-2 userauth and connection layers. */ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, struct Packet *pktin) @@ -6374,7 +6602,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->p = s->response + 5; s->nkeys = GET_32BIT(s->p); s->p += 4; - logeventf(ssh, "Pageant has %d SSH2 keys", s->nkeys); + logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys); for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { void *vret; @@ -6593,6 +6821,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, continue; } + c_write_str(ssh, "Using keyboard-interactive authentication.\r\n"); s->kbd_inter_running = TRUE; s->curr_prompt = 0; } @@ -7117,6 +7346,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } else { subsys = ssh->cfg.ssh_subsys; cmd = ssh->cfg.remote_cmd_ptr; + if (!cmd) cmd = ssh->cfg.remote_cmd; } s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); @@ -7201,30 +7431,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* * Try to send data on all channels if we can. */ - for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { - int bufsize; - if (c->closes) - continue; /* don't send on closing channels */ - bufsize = ssh2_try_send(c); - if (bufsize == 0) { - switch (c->type) { - case CHAN_MAINSESSION: - /* stdin need not receive an unthrottle - * notification since it will be polled */ - break; - case CHAN_X11: - x11_unthrottle(c->u.x11.s); - break; - case CHAN_AGENT: - /* agent sockets are request/response and need no - * buffer management */ - break; - case CHAN_SOCKDATA: - pfd_unthrottle(c->u.pfd.s); - break; - } - } - } + for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) + ssh2_try_send_and_unthrottle(c); } } @@ -7232,7 +7440,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } /* - * Handlers for SSH2 messages that might arrive at any moment. + * Handlers for SSH-2 messages that might arrive at any moment. */ static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) { @@ -7290,7 +7498,7 @@ static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) } /* - * Handle the top-level SSH2 protocol. + * Handle the top-level SSH-2 protocol. */ static void ssh2_protocol_setup(Ssh ssh) { @@ -7344,7 +7552,7 @@ static void ssh2_protocol_setup(Ssh ssh) * These special message types we install handlers for. */ ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect; - ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */ + ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */ ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug; } @@ -7352,6 +7560,9 @@ static void ssh2_timer(void *ctx, long now) { Ssh ssh = (Ssh)ctx; + if (ssh->state == SSH_STATE_CLOSED) + return; + if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 && now - ssh->next_rekey >= 0) { do_ssh2_transport(ssh, "timeout", -1, NULL); @@ -7463,6 +7674,8 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->queueing = FALSE; ssh->qhead = ssh->qtail = NULL; ssh->deferred_rekey_reason = NULL; + bufchain_init(&ssh->queued_incoming_data); + ssh->frozen = FALSE; *backend_handle = ssh; @@ -7589,6 +7802,7 @@ static void ssh_free(void *handle) expire_timer_context(ssh); if (ssh->pinger) pinger_free(ssh->pinger); + bufchain_clear(&ssh->queued_incoming_data); sfree(ssh); random_unref(); @@ -7833,6 +8047,7 @@ static void ssh_special(void *handle, Telnet_Special code) struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); ssh2_pkt_send(ssh, pktout); + ssh->send_ok = 0; /* now stop trying to read from stdin */ } logevent("Sent EOF message"); } else if (code == TS_PING || code == TS_NOP) { @@ -7854,7 +8069,7 @@ static void ssh_special(void *handle, Telnet_Special code) if (ssh->state == SSH_STATE_CLOSED || ssh->state == SSH_STATE_PREPACKET) return; if (ssh->version == 1) { - logevent("Unable to send BREAK signal in SSH1"); + logevent("Unable to send BREAK signal in SSH-1"); } else if (ssh->mainchan) { pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);