return 0;
}
const static struct ssh_compress ssh_comp_none = {
- "none",
+ "none", NULL,
ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
ssh_comp_none_disable, NULL
sfree(s->response);
if (s->publickey_blob && !s->tried_publickey)
logevent("Configured key file not in Pageant");
- }
+ } else {
+ logevent("Failed to get reply from Pageant");
+ }
if (s->authed)
break;
}
int n_preferred_ciphers;
const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
const struct ssh_compress *preferred_comp;
+ int userauth_succeeded; /* for delayed compression */
+ int pending_compression;
int got_session_id, activated_authconn;
struct Packet *pktout;
int dlgret;
s->cscomp_tobe = s->sccomp_tobe = NULL;
s->got_session_id = s->activated_authconn = FALSE;
+ s->userauth_succeeded = FALSE;
+ s->pending_compression = FALSE;
/*
* Be prepared to work around the buggy MAC problem.
if (i < s->nmacs - 1)
ssh2_pkt_addstring_str(s->pktout, ",");
}
- /* List client->server compression algorithms. */
- ssh2_pkt_addstring_start(s->pktout);
- assert(lenof(compressions) > 1);
- ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
- for (i = 0; i < lenof(compressions); i++) {
- const struct ssh_compress *c = compressions[i];
- if (c != s->preferred_comp) {
+ /* List client->server compression algorithms,
+ * then server->client compression algorithms. (We use the
+ * same set twice.) */
+ for (j = 0; j < 2; j++) {
+ ssh2_pkt_addstring_start(s->pktout);
+ assert(lenof(compressions) > 1);
+ /* Prefer non-delayed versions */
+ ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
+ /* We don't even list delayed versions of algorithms until
+ * they're allowed to be used, to avoid a race. See the end of
+ * this function. */
+ if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
ssh2_pkt_addstring_str(s->pktout, ",");
- ssh2_pkt_addstring_str(s->pktout, c->name);
+ ssh2_pkt_addstring_str(s->pktout,
+ s->preferred_comp->delayed_name);
}
- }
- /* List server->client compression algorithms. */
- ssh2_pkt_addstring_start(s->pktout);
- assert(lenof(compressions) > 1);
- ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
- for (i = 0; i < lenof(compressions); i++) {
- const struct ssh_compress *c = compressions[i];
- if (c != s->preferred_comp) {
- ssh2_pkt_addstring_str(s->pktout, ",");
- ssh2_pkt_addstring_str(s->pktout, c->name);
+ for (i = 0; i < lenof(compressions); i++) {
+ const struct ssh_compress *c = compressions[i];
+ if (c != s->preferred_comp) {
+ ssh2_pkt_addstring_str(s->pktout, ",");
+ ssh2_pkt_addstring_str(s->pktout, c->name);
+ if (s->userauth_succeeded && c->delayed_name) {
+ ssh2_pkt_addstring_str(s->pktout, ",");
+ ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
+ }
+ }
}
}
/* List client->server languages. Empty list. */
if (in_commasep_string(c->name, str, len)) {
s->cscomp_tobe = c;
break;
+ } else if (in_commasep_string(c->delayed_name, str, len)) {
+ if (s->userauth_succeeded) {
+ s->cscomp_tobe = c;
+ break;
+ } else {
+ s->pending_compression = TRUE; /* try this later */
+ }
}
}
ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
if (in_commasep_string(c->name, str, len)) {
s->sccomp_tobe = c;
break;
+ } else if (in_commasep_string(c->delayed_name, str, len)) {
+ if (s->userauth_succeeded) {
+ s->sccomp_tobe = c;
+ break;
+ } else {
+ s->pending_compression = TRUE; /* try this later */
+ }
}
}
+ if (s->pending_compression) {
+ logevent("Server supports delayed compression; "
+ "will try this later");
+ }
ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
* start.
*
* We _also_ go back to the start if we see pktin==NULL and
- * inlen==-1, because this is a special signal meaning
+ * inlen negative, because this is a special signal meaning
* `initiate client-driven rekey', and `in' contains a message
* giving the reason for the rekey.
+ *
+ * inlen==-1 means always initiate a rekey;
+ * inlen==-2 means that userauth has completed successfully and
+ * we should consider rekeying (for delayed compression).
*/
while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
- (!pktin && inlen == -1))) {
+ (!pktin && inlen < 0))) {
wait_for_rekey:
crReturn(1);
}
if (pktin) {
logevent("Server initiated key re-exchange");
} else {
+ if (inlen == -2) {
+ /*
+ * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
+ * delayed compression, if it's available.
+ *
+ * draft-miller-secsh-compression-delayed-00 says that you
+ * negotiate delayed compression in the first key exchange, and
+ * both sides start compressing when the server has sent
+ * USERAUTH_SUCCESS. This has a race condition -- the server
+ * can't know when the client has seen it, and thus which incoming
+ * packets it should treat as compressed.
+ *
+ * Instead, we do the initial key exchange without offering the
+ * delayed methods, but note if the server offers them; when we
+ * get here, if a delayed method was available that was higher
+ * on our list than what we got, we initiate a rekey in which we
+ * _do_ list the delayed methods (and hopefully get it as a
+ * result). Subsequent rekeys will do the same.
+ */
+ assert(!s->userauth_succeeded); /* should only happen once */
+ s->userauth_succeeded = TRUE;
+ if (!s->pending_compression)
+ /* Can't see any point rekeying. */
+ goto wait_for_rekey; /* this is utterly horrid */
+ /* else fall through to rekey... */
+ s->pending_compression = FALSE;
+ }
/*
+ * Now we've decided to rekey.
+ *
* Special case: if the server bug is set that doesn't
* allow rekeying, we give a different log message and
* continue waiting. (If such a server _initiates_ a rekey,
schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
ssh2_timer, ssh);
}
- goto wait_for_rekey; /* this is utterly horrid */
+ goto wait_for_rekey; /* this is still utterly horrid */
} else {
logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
}
return c;
}
+static int ssh2_handle_winadj_response(struct ssh_channel *c)
+{
+ struct winadj *wa = c->v.v2.winadj_head;
+ if (!wa)
+ return FALSE;
+ c->v.v2.winadj_head = wa->next;
+ c->v.v2.remlocwin += wa->size;
+ sfree(wa);
+ /*
+ * winadj messages are only sent when the window is fully open, so
+ * if we get an ack of one, we know any pending unthrottle is
+ * complete.
+ */
+ if (c->v.v2.throttle_state == UNTHROTTLING)
+ c->v.v2.throttle_state = UNTHROTTLED;
+ return TRUE;
+}
+
static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin)
{
/*
* This should never get called. All channel requests are either
- * sent with want_reply false or are sent before this handler gets
- * installed.
+ * sent with want_reply false, are sent before this handler gets
+ * installed, or are "winadj@putty" requests, which servers should
+ * never respond to with success.
+ *
+ * However, at least one server ("boks_sshd") is known to return
+ * SUCCESS for channel requests it's never heard of, such as
+ * "winadj@putty". Raised with foxt.com as bug 090916-090424, but
+ * for the sake of a quiet life, we handle it just the same as the
+ * expected FAILURE.
*/
struct ssh_channel *c;
- struct winadj *wa;
c = ssh2_channel_msg(ssh, pktin);
if (!c)
return;
- wa = c->v.v2.winadj_head;
- if (wa)
- ssh_disconnect(ssh, NULL, "Received SSH_MSG_CHANNEL_SUCCESS for "
- "\"winadj@putty.projects.tartarus.org\"",
- SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
- else
+ if (!ssh2_handle_winadj_response(c))
ssh_disconnect(ssh, NULL,
"Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
* installed.
*/
struct ssh_channel *c;
- struct winadj *wa;
c = ssh2_channel_msg(ssh, pktin);
if (!c)
return;
- wa = c->v.v2.winadj_head;
- if (!wa) {
+ if (!ssh2_handle_winadj_response(c))
ssh_disconnect(ssh, NULL,
"Received unsolicited SSH_MSG_CHANNEL_FAILURE",
SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
- return;
- }
- c->v.v2.winadj_head = wa->next;
- c->v.v2.remlocwin += wa->size;
- sfree(wa);
- /*
- * winadj messages are only sent when the window is fully open, so
- * if we get an ack of one, we know any pending unthrottle is
- * complete.
- */
- if (c->v.v2.throttle_state == UNTHROTTLING)
- c->v.v2.throttle_state = UNTHROTTLED;
}
static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
int tried_gssapi;
#endif
int kbd_inter_refused;
- int we_are_in;
+ int we_are_in, userauth_success;
prompts_t *cur_prompt;
int num_prompts;
char username[100];
crBegin(ssh->do_ssh2_authconn_crstate);
s->done_service_req = FALSE;
- s->we_are_in = FALSE;
+ s->we_are_in = s->userauth_success = FALSE;
#ifndef NO_GSSAPI
s->tried_gssapi = FALSE;
#endif
s->nkeys = 0;
}
}
+ } else {
+ logevent("Failed to get reply from Pageant");
}
}
}
if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
logevent("Access granted");
- s->we_are_in = TRUE;
+ s->we_are_in = s->userauth_success = TRUE;
break;
}
if (s->agent_response)
sfree(s->agent_response);
+ if (s->userauth_success) {
+ /*
+ * We've just received USERAUTH_SUCCESS, and we haven't sent any
+ * packets since. Signal the transport layer to consider enacting
+ * delayed compression.
+ *
+ * (Relying on we_are_in is not sufficient, as
+ * draft-miller-secsh-compression-delayed is quite clear that it
+ * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
+ * become set for other reasons.)
+ */
+ do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
+ }
+
/*
* Now the connection protocol has started, one way or another.
*/
/* log the debug message */
char *msg;
int msglen;
- int always_display;
- /* XXX maybe we should actually take notice of this */
- always_display = ssh2_pkt_getbool(pktin);
+ /* XXX maybe we should actually take notice of the return value */
+ ssh2_pkt_getbool(pktin);
ssh_pkt_getstring(pktin, &msg, &msglen);
logeventf(ssh, "Remote debug message: %.*s", msglen, msg);