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
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);
*/
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;
}
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;
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);
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;
}
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);
}
}
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;
Bignum challenge;
char *commentp;
int commentlen;
+ int dlgret;
};
crState(do_ssh1_login_state);
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++) {
/* 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);
+ }
}
}
}
} else {
while (*portfwd_strptr) portfwd_strptr++;
+ host[0] = 0;
+ dports[0] = 0;
dport = dserv = -1;
portfwd_strptr++; /* eat the NUL and move to next one */
}
*/
{
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;
{
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;
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);
* 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"));
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)",
* 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)) {
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)) {
}
}
}
- 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)",
}
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)) {
}
}
}
- 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)",
}
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 */
}
/*
* Now generate and send e for Diffie-Hellman.
*/
+ set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
s->pktout = ssh2_pkt_init(s->kex_init_value);
ssh2_pkt_addmp(s->pktout, s->e);
ssh2_pkt_send_noqueue(ssh, s->pktout);
+ set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
crWaitUntil(pktin);
if (pktin->type != s->kex_reply_value) {
bombout(("expected key exchange reply packet from server"));
crStop(0);
}
+ set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
s->f = ssh2_pkt_getmp(pktin);
if (!s->f) {
s->K = dh_find_K(ssh->kex_ctx, s->f);
+ /* We assume everything from now on will be quick, and it might
+ * involve user interaction. */
+ set_busy_status(ssh->frontend, BUSY_NOT);
+
sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
if (ssh->kex == &ssh_diffiehellman_gex) {
sha_uint32(&ssh->exhash, s->pbits);
*/
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);
} 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);
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;
expire_timer_context(ssh);
if (ssh->pinger)
pinger_free(ssh->pinger);
+ bufchain_clear(&ssh->queued_incoming_data);
sfree(ssh);
random_unref();