X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/b589b81633faec635857516c3f6cc6b89af62d03..d7e843be6c921713cd346492600679bb9a13dcc2:/ssh.c diff --git a/ssh.c b/ssh.c index 0aec421e..27a4fab6 100644 --- a/ssh.c +++ b/ssh.c @@ -13,6 +13,7 @@ #include "tree234.h" #include "ssh.h" #ifndef NO_GSSAPI +#include "sshgssc.h" #include "sshgss.h" #endif @@ -194,6 +195,7 @@ static const char *const ssh2_disconnect_reasons[] = { #define BUG_SSH2_REKEY 64 #define BUG_SSH2_PK_SESSIONID 128 #define BUG_SSH2_MAXPKT 256 +#define BUG_CHOKES_ON_SSH2_IGNORE 512 /* * Codes for terminal modes. @@ -588,6 +590,17 @@ struct ssh_channel { * A channel is completely finished with when all four bits are set. */ int closes; + + /* + * This flag indicates that a close is pending on the outgoing + * side of the channel: that is, wherever we're getting the data + * for this channel has sent us some data followed by EOF. We + * can't actually close the channel until we've finished sending + * the data, so we set this flag instead to remind us to + * initiate the closing process once our buffer is clear. + */ + int pending_close; + /* * True if this channel is causing the underlying connection to be * throttled. @@ -928,6 +941,13 @@ struct ssh_tag { * Fully qualified host name, which we need if doing GSSAPI. */ char *fullhostname; + +#ifndef NO_GSSAPI + /* + * GSSAPI libraries for this session. + */ + struct ssh_gss_liblist *gsslibs; +#endif }; #define logevent(s) logevent(ssh->frontend, s) @@ -2011,7 +2031,8 @@ static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore) { int len; if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) && - ssh->deferred_len == 0 && !noignore) { + ssh->deferred_len == 0 && !noignore && + !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { /* * Interpose an SSH_MSG_IGNORE to ensure that user data don't * get encrypted with a known IV. @@ -2141,7 +2162,8 @@ static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt, * unavailable, we don't do this trick at all, because we * gain nothing by it.) */ - if (ssh->cscipher) { + if (ssh->cscipher && + !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { int stringlen, i; stringlen = (256 - ssh->deferred_len); @@ -2508,6 +2530,15 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) ssh->remote_bugs |= BUG_SSH2_MAXPKT; logevent("We believe remote version ignores SSH-2 maximum packet size"); } + + if (ssh->cfg.sshbug_ignore2 == FORCE_ON) { + /* + * Servers that don't support SSH2_MSG_IGNORE. Currently, + * none detected automatically. + */ + ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE; + logevent("We believe remote version has SSH-2 ignore bug"); + } } /* @@ -2853,6 +2884,8 @@ static int ssh_do_close(Ssh ssh, int notify_exit) del234(ssh->portfwds, pf); /* moving next one to index 0 */ free_portfwd(pf); } + freetree234(ssh->portfwds); + ssh->portfwds = NULL; } return ret; @@ -4138,7 +4171,7 @@ void sshfwd_close(struct ssh_channel *c) if (ssh->state == SSH_STATE_CLOSED) return; - if (c && !c->closes) { + if (!c->closes) { /* * If halfopen is true, we have sent * CHANNEL_OPEN for this channel, but it hasn't even been @@ -4150,14 +4183,42 @@ void sshfwd_close(struct ssh_channel *c) if (ssh->version == 1) { send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END); + c->closes = 1; /* sent MSG_CLOSE */ } else { - struct Packet *pktout; - pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); - ssh2_pkt_adduint32(pktout, c->remoteid); - ssh2_pkt_send(ssh, pktout); + int bytes_to_send = bufchain_size(&c->v.v2.outbuffer); + if (bytes_to_send > 0) { + /* + * If we still have unsent data in our outgoing + * buffer for this channel, we can't actually + * initiate a close operation yet or that data + * will be lost. Instead, set the pending_close + * flag so that when we do clear the buffer + * we'll start closing the channel. + */ + char logmsg[160] = {'\0'}; + sprintf( + logmsg, + "Forwarded port pending to be closed : " + "%d bytes remaining", + bytes_to_send); + logevent(logmsg); + + c->pending_close = TRUE; + } else { + /* + * No locally buffered data, so we can send the + * close message immediately. + */ + struct Packet *pktout; + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + c->closes = 1; /* sent MSG_CLOSE */ + logevent("Nothing left to send, closing channel"); + } } } - c->closes = 1; /* sent MSG_CLOSE */ + if (c->type == CHAN_X11) { c->u.x11.s = NULL; logevent("Forwarded X11 connection terminated"); @@ -4296,6 +4357,7 @@ static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx) rpf = del234(ssh->rportfwds, pf); assert(rpf == pf); + pf->pfrec->remote = NULL; free_rportfwd(pf); } } @@ -4427,12 +4489,19 @@ static void ssh_setup_portfwd(Ssh ssh, const Config *cfg) epfrec = add234(ssh->portfwds, pfrec); if (epfrec != pfrec) { + if (epfrec->status == DESTROY) { + /* + * We already have a port forwarding up and running + * with precisely these parameters. Hence, no need + * to do anything; simply re-tag the existing one + * as KEEP. + */ + epfrec->status = KEEP; + } /* - * We already have a port forwarding with precisely - * these parameters. Hence, no need to do anything; - * simply tag the existing one as KEEP. + * Anything else indicates that there was a duplicate + * in our input, which we'll silently ignore. */ - epfrec->status = KEEP; free_portfwd(pfrec); } else { pfrec->status = CREATE; @@ -4465,6 +4534,8 @@ static void ssh_setup_portfwd(Ssh ssh, const Config *cfg) logeventf(ssh, "Cancelling %s", message); sfree(message); + /* epf->remote or epf->local may be NULL if setting up a + * forwarding failed. */ if (epf->remote) { struct ssh_rportfwd *rpf = epf->remote; struct Packet *pktout; @@ -4674,6 +4745,7 @@ static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin) c->halfopen = FALSE; c->localid = alloc_channel_id(ssh); c->closes = 0; + c->pending_close = FALSE; c->throttling_conn = 0; c->type = CHAN_X11; /* identify channel type */ add234(ssh->channels, c); @@ -4703,6 +4775,7 @@ static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin) c->halfopen = FALSE; c->localid = alloc_channel_id(ssh); c->closes = 0; + c->pending_close = FALSE; c->throttling_conn = 0; c->type = CHAN_AGENT; /* identify channel type */ c->u.a.lensofar = 0; @@ -4757,6 +4830,7 @@ static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin) c->halfopen = FALSE; c->localid = alloc_channel_id(ssh); c->closes = 0; + c->pending_close = FALSE; c->throttling_conn = 0; c->type = CHAN_SOCKDATA; /* identify channel type */ add234(ssh->channels, c); @@ -6323,7 +6397,7 @@ 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) +static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c) { int bufsize; if (c->closes) @@ -6347,6 +6421,19 @@ static void ssh2_try_send_and_unthrottle(struct ssh_channel *c) break; } } + + /* + * If we've emptied the channel's output buffer and there's a + * pending close event, start the channel-closing procedure. + */ + if (c->pending_close && bufchain_size(&c->v.v2.outbuffer) == 0) { + struct Packet *pktout; + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); + ssh2_pkt_adduint32(pktout, c->remoteid); + ssh2_pkt_send(ssh, pktout); + c->closes = 1; + c->pending_close = FALSE; + } } /* @@ -6357,6 +6444,7 @@ static void ssh2_channel_init(struct ssh_channel *c) Ssh ssh = c->ssh; c->localid = alloc_channel_id(ssh); c->closes = 0; + c->pending_close = FALSE; c->throttling_conn = FALSE; c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin = ssh->cfg.ssh_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE; @@ -6540,7 +6628,7 @@ static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) return; if (!c->closes) { c->v.v2.remwindow += ssh_pkt_getuint32(pktin); - ssh2_try_send_and_unthrottle(c); + ssh2_try_send_and_unthrottle(ssh, c); } } @@ -6661,11 +6749,13 @@ static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin) * wrap up and close the channel ourselves. */ x11_close(c->u.x11.s); + c->u.x11.s = NULL; sshfwd_close(c); } else if (c->type == CHAN_AGENT) { sshfwd_close(c); } else if (c->type == CHAN_SOCKDATA) { pfd_close(c->u.pfd.s); + c->u.pfd.s = NULL; sshfwd_close(c); } } @@ -7186,6 +7276,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int num_env, env_left, env_ok; struct Packet *pktout; #ifndef NO_GSSAPI + struct ssh_gss_library *gsslib; Ssh_gss_ctx gss_ctx; Ssh_gss_buf gss_buf; Ssh_gss_buf gss_rcvtok, gss_sndtok; @@ -7454,6 +7545,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } while (1) { + char *methods = NULL; + int methlen = 0; + /* * Wait for the result of the last authentication request. */ @@ -7503,8 +7597,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * helpfully try next. */ if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) { - char *methods; - int methlen; ssh_pkt_getstring(pktin, &methods, &methlen); if (!ssh2_pkt_getbool(pktin)) { /* @@ -7560,10 +7652,12 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, in_commasep_string("password", methods, methlen); s->can_keyb_inter = ssh->cfg.try_ki_auth && in_commasep_string("keyboard-interactive", methods, methlen); -#ifndef NO_GSSAPI +#ifndef NO_GSSAPI + if (!ssh->gsslibs) + ssh->gsslibs = ssh_gss_setup(&ssh->cfg); s->can_gssapi = ssh->cfg.try_gssapi_auth && - in_commasep_string("gssapi-with-mic", methods, methlen) && - ssh_gss_init(); + in_commasep_string("gssapi-with-mic", methods, methlen) && + ssh->gsslibs->nlibraries > 0; #endif } @@ -7906,6 +8000,35 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->gotit = TRUE; ssh->pkt_actx = SSH2_PKTCTX_GSSAPI; + /* + * Pick the highest GSS library on the preference + * list. + */ + { + int i, j; + s->gsslib = NULL; + for (i = 0; i < ngsslibs; i++) { + int want_id = ssh->cfg.ssh_gsslist[i]; + for (j = 0; j < ssh->gsslibs->nlibraries; j++) + if (ssh->gsslibs->libraries[j].id == want_id) { + s->gsslib = &ssh->gsslibs->libraries[j]; + goto got_gsslib; /* double break */ + } + } + got_gsslib: + /* + * We always expect to have found something in + * the above loop: we only came here if there + * was at least one viable GSS library, and the + * preference list should always mention + * everything and only change the order. + */ + assert(s->gsslib); + } + + if (s->gsslib->gsslogmsg) + logevent(s->gsslib->gsslogmsg); + /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */ s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); ssh2_pkt_addstring(s->pktout, s->username); @@ -7913,7 +8036,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_addstring(s->pktout, "gssapi-with-mic"); /* add mechanism info */ - ssh_gss_indicate_mech(&s->gss_buf); + s->gsslib->indicate_mech(s->gsslib, &s->gss_buf); /* number of GSSAPI mechanisms */ ssh2_pkt_adduint32(s->pktout,1); @@ -7949,8 +8072,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } /* now start running */ - s->gss_stat = ssh_gss_import_name(ssh->fullhostname, - &s->gss_srv_name); + s->gss_stat = s->gsslib->import_name(s->gsslib, + ssh->fullhostname, + &s->gss_srv_name); if (s->gss_stat != SSH_GSS_OK) { if (s->gss_stat == SSH_GSS_BAD_HOST_NAME) logevent("GSSAPI import name failed - Bad service name"); @@ -7960,11 +8084,11 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } /* fetch TGT into GSS engine */ - s->gss_stat = ssh_gss_acquire_cred(&s->gss_ctx); + s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx); if (s->gss_stat != SSH_GSS_OK) { logevent("GSSAPI authentication failed to get credentials"); - ssh_gss_release_name(&s->gss_srv_name); + s->gsslib->release_name(s->gsslib, &s->gss_srv_name); continue; } @@ -7974,17 +8098,20 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* now enter the loop */ do { - s->gss_stat = ssh_gss_init_sec_context(&s->gss_ctx, - s->gss_srv_name, - ssh->cfg.gssapifwd, - &s->gss_rcvtok, - &s->gss_sndtok); + s->gss_stat = s->gsslib->init_sec_context + (s->gsslib, + &s->gss_ctx, + s->gss_srv_name, + ssh->cfg.gssapifwd, + &s->gss_rcvtok, + &s->gss_sndtok); if (s->gss_stat!=SSH_GSS_S_COMPLETE && s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) { logevent("GSSAPI authentication initialisation failed"); - if (ssh_gss_display_status(s->gss_ctx,&s->gss_buf) == SSH_GSS_OK) { + if (s->gsslib->display_status(s->gsslib, s->gss_ctx, + &s->gss_buf) == SSH_GSS_OK) { logevent(s->gss_buf.value); sfree(s->gss_buf.value); } @@ -8001,7 +8128,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh_pkt_addstring_start(s->pktout); ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length); ssh2_pkt_send(ssh, s->pktout); - ssh_gss_free_tok(&s->gss_sndtok); + s->gsslib->free_tok(s->gsslib, &s->gss_sndtok); } if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) { @@ -8018,8 +8145,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED); if (s->gss_stat != SSH_GSS_OK) { - ssh_gss_release_name(&s->gss_srv_name); - ssh_gss_release_cred(&s->gss_ctx); + s->gsslib->release_name(s->gsslib, &s->gss_srv_name); + s->gsslib->release_cred(s->gsslib, &s->gss_ctx); continue; } logevent("GSSAPI authentication loop finished OK"); @@ -8038,17 +8165,17 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->gss_buf.value = (char *)s->pktout->data + micoffset; s->gss_buf.length = s->pktout->length - micoffset; - ssh_gss_get_mic(s->gss_ctx, &s->gss_buf, &mic); + s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic); s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC); ssh_pkt_addstring_start(s->pktout); ssh_pkt_addstring_data(s->pktout, mic.value, mic.length); ssh2_pkt_send(ssh, s->pktout); - ssh_gss_free_mic(&mic); + s->gsslib->free_mic(s->gsslib, &mic); s->gotit = FALSE; - ssh_gss_release_name(&s->gss_srv_name); - ssh_gss_release_cred(&s->gss_ctx); + s->gsslib->release_name(s->gsslib, &s->gss_srv_name); + s->gsslib->release_cred(s->gsslib, &s->gss_ctx); continue; #endif } else if (s->can_keyb_inter && !s->kbd_inter_refused) { @@ -8434,11 +8561,16 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, sfree(s->password); } else { + char *str = dupprintf("No supported authentication methods available" + " (server sent: %.*s)", + methlen, methods); - ssh_disconnect(ssh, NULL, + ssh_disconnect(ssh, str, "No supported authentication methods available", SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE, FALSE); + sfree(str); + crStopV; } @@ -8877,7 +9009,7 @@ 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++) - ssh2_try_send_and_unthrottle(c); + ssh2_try_send_and_unthrottle(ssh, c); } } @@ -9159,6 +9291,10 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data); ssh->kex_in_progress = FALSE; +#ifndef NO_GSSAPI + ssh->gsslibs = NULL; +#endif + p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive); if (p != NULL) return p; @@ -9231,7 +9367,7 @@ static void ssh_free(void *handle) if (ssh->rportfwds) { while ((pf = delpos234(ssh->rportfwds, 0)) != NULL) - sfree(pf); + free_rportfwd(pf); freetree234(ssh->rportfwds); ssh->rportfwds = NULL; } @@ -9255,6 +9391,10 @@ static void ssh_free(void *handle) if (ssh->pinger) pinger_free(ssh->pinger); bufchain_clear(&ssh->queued_incoming_data); +#ifndef NO_GSSAPI + if (ssh->gsslibs) + ssh_gss_cleanup(ssh->gsslibs); +#endif sfree(ssh); random_unref(); @@ -9415,8 +9555,10 @@ static const struct telnet_special *ssh_get_specials(void *handle) static const struct telnet_special ssh1_ignore_special[] = { {"IGNORE message", TS_NOP} }; - static const struct telnet_special ssh2_transport_specials[] = { + static const struct telnet_special ssh2_ignore_special[] = { {"IGNORE message", TS_NOP}, + }; + static const struct telnet_special ssh2_rekey_special[] = { {"Repeat key exchange", TS_REKEY}, }; static const struct telnet_special ssh2_session_specials[] = { @@ -9441,7 +9583,8 @@ static const struct telnet_special *ssh_get_specials(void *handle) {NULL, TS_EXITMENU} }; /* XXX review this length for any changes: */ - static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) + + static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) + + lenof(ssh2_rekey_special) + lenof(ssh2_session_specials) + lenof(specials_end)]; Ssh ssh = (Ssh) handle; @@ -9460,7 +9603,10 @@ static const struct telnet_special *ssh_get_specials(void *handle) if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) ADD_SPECIALS(ssh1_ignore_special); } else if (ssh->version == 2) { - ADD_SPECIALS(ssh2_transport_specials); + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) + ADD_SPECIALS(ssh2_ignore_special); + if (!(ssh->remote_bugs & BUG_SSH2_REKEY)) + ADD_SPECIALS(ssh2_rekey_special); if (ssh->mainchan) ADD_SPECIALS(ssh2_session_specials); } /* else we're not ready yet */ @@ -9510,9 +9656,11 @@ static void ssh_special(void *handle, Telnet_Special code) if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END); } else { - pktout = ssh2_pkt_init(SSH2_MSG_IGNORE); - ssh2_pkt_addstring_start(pktout); - ssh2_pkt_send_noqueue(ssh, pktout); + if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) { + pktout = ssh2_pkt_init(SSH2_MSG_IGNORE); + ssh2_pkt_addstring_start(pktout); + ssh2_pkt_send_noqueue(ssh, pktout); + } } } else if (code == TS_REKEY) { if (!ssh->kex_in_progress && ssh->version == 2) {