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-rw-r--r--tools/plink/ssh.c240
1 files changed, 194 insertions, 46 deletions
diff --git a/tools/plink/ssh.c b/tools/plink/ssh.c
index 89c0433ca..7c9b929de 100644
--- a/tools/plink/ssh.c
+++ b/tools/plink/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) {
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-09 14:57:40 +0000