+void sshfwd_close(struct ssh_channel *c)
+{
+ Ssh ssh = c->ssh;
+
+ if (ssh->state != SSH_STATE_SESSION) {
+ assert(ssh->state == SSH_STATE_CLOSED);
+ return;
+ }
+
+ if (c && !c->closes) {
+ /*
+ * If the channel's remoteid is -1, we have sent
+ * CHANNEL_OPEN for this channel, but it hasn't even been
+ * acknowledged by the server. So we must set a close flag
+ * on it now, and then when the server acks the channel
+ * open, we can close it then.
+ */
+ if (((int)c->remoteid) != -1) {
+ if (ssh->version == 1) {
+ send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
+ PKT_END);
+ } else {
+ 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 */
+ if (c->type == CHAN_X11) {
+ c->u.x11.s = NULL;
+ logevent("Forwarded X11 connection terminated");
+ } else if (c->type == CHAN_SOCKDATA ||
+ c->type == CHAN_SOCKDATA_DORMANT) {
+ c->u.pfd.s = NULL;
+ logevent("Forwarded port closed");
+ }
+ }
+}
+
+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);
+ return 0;
+ }
+
+ if (ssh->version == 1) {
+ send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
+ PKT_INT, c->remoteid,
+ PKTT_DATA,
+ PKT_INT, len, PKT_DATA, buf, len,
+ PKTT_OTHER, PKT_END);
+ /*
+ * In SSH1 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
+ * _everything_ will be throttled as a whole.
+ */
+ return 0;
+ } else {
+ ssh2_add_channel_data(c, buf, len);
+ return ssh2_try_send(c);
+ }
+}
+
+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);
+ return;
+ }
+
+ if (ssh->version == 1) {
+ if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
+ c->v.v1.throttling = 0;
+ ssh1_throttle(ssh, -1);
+ }
+ } else {
+ ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
+ }
+}
+
+static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
+{
+ struct queued_handler *qh = ssh->qhead;
+
+ assert(qh != NULL);
+
+ assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
+
+ if (qh->msg1 > 0) {
+ assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
+ ssh->packet_dispatch[qh->msg1] = NULL;
+ }
+ if (qh->msg2 > 0) {
+ assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
+ ssh->packet_dispatch[qh->msg2] = NULL;
+ }
+
+ if (qh->next) {
+ ssh->qhead = qh->next;
+
+ if (ssh->qhead->msg1 > 0) {
+ assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
+ ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
+ }
+ if (ssh->qhead->msg2 > 0) {
+ assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
+ ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
+ }
+ } else {
+ ssh->qhead = ssh->qtail = NULL;
+ ssh->packet_dispatch[pktin->type] = NULL;
+ }
+
+ qh->handler(ssh, pktin, qh->ctx);
+
+ sfree(qh);
+}
+
+static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
+ chandler_fn_t handler, void *ctx)
+{
+ struct queued_handler *qh;
+
+ qh = snew(struct queued_handler);
+ qh->msg1 = msg1;
+ qh->msg2 = msg2;
+ qh->handler = handler;
+ qh->ctx = ctx;
+ qh->next = NULL;
+
+ if (ssh->qtail == NULL) {
+ ssh->qhead = qh;
+
+ if (qh->msg1 > 0) {
+ assert(ssh->packet_dispatch[qh->msg1] == NULL);
+ ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
+ }
+ if (qh->msg2 > 0) {
+ assert(ssh->packet_dispatch[qh->msg2] == NULL);
+ ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
+ }
+ } else {
+ ssh->qtail->next = qh;
+ }
+ ssh->qtail = qh;
+}
+
+static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
+{
+ struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
+
+ if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
+ SSH2_MSG_REQUEST_SUCCESS)) {
+ logeventf(ssh, "Remote port forwarding from %s enabled",
+ pf->sportdesc);
+ } else {
+ logeventf(ssh, "Remote port forwarding from %s refused",
+ pf->sportdesc);
+
+ rpf = del234(ssh->rportfwds, pf);
+ assert(rpf == pf);
+ free_rportfwd(pf);
+ }
+}
+
+static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
+{
+ const char *portfwd_strptr = cfg->portfwd;
+ struct ssh_portfwd *epf;
+ int i;
+
+ if (!ssh->portfwds) {
+ ssh->portfwds = newtree234(ssh_portcmp);
+ } else {
+ /*
+ * Go through the existing port forwardings and tag them
+ * with status==DESTROY. Any that we want to keep will be
+ * re-enabled (status==KEEP) as we go through the
+ * configuration and find out which bits are the same as
+ * they were before.
+ */
+ struct ssh_portfwd *epf;
+ int i;
+ for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
+ epf->status = DESTROY;
+ }
+
+ while (*portfwd_strptr) {
+ char address_family, type;
+ int sport,dport,sserv,dserv;
+ char sports[256], dports[256], saddr[256], host[256];
+ int n;
+
+ address_family = 'A';
+ type = 'L';
+ if (*portfwd_strptr == 'A' ||
+ *portfwd_strptr == '4' ||
+ *portfwd_strptr == '6')
+ address_family = *portfwd_strptr++;
+ if (*portfwd_strptr == 'L' ||
+ *portfwd_strptr == 'R' ||
+ *portfwd_strptr == 'D')
+ type = *portfwd_strptr++;
+
+ saddr[0] = '\0';
+
+ n = 0;
+ while (*portfwd_strptr && *portfwd_strptr != '\t') {
+ if (*portfwd_strptr == ':') {
+ /*
+ * We've seen a colon in the middle of the
+ * source port number. This means that
+ * everything we've seen until now is the
+ * source _address_, so we'll move it into
+ * saddr and start sports from the beginning
+ * again.
+ */
+ portfwd_strptr++;
+ sports[n] = '\0';
+ if (ssh->version == 1 && type == 'R') {
+ logeventf(ssh, "SSH1 cannot handle remote source address "
+ "spec \"%s\"; ignoring", sports);
+ } else
+ strcpy(saddr, sports);
+ n = 0;
+ }
+ if (n < 255) sports[n++] = *portfwd_strptr++;
+ }
+ sports[n] = 0;
+ if (type != 'D') {
+ if (*portfwd_strptr == '\t')
+ portfwd_strptr++;
+ n = 0;
+ while (*portfwd_strptr && *portfwd_strptr != ':') {
+ if (n < 255) host[n++] = *portfwd_strptr++;
+ }
+ host[n] = 0;
+ if (*portfwd_strptr == ':')
+ portfwd_strptr++;
+ n = 0;
+ while (*portfwd_strptr) {
+ if (n < 255) dports[n++] = *portfwd_strptr++;
+ }
+ dports[n] = 0;
+ portfwd_strptr++;
+ dport = atoi(dports);
+ dserv = 0;
+ if (dport == 0) {
+ dserv = 1;
+ dport = net_service_lookup(dports);
+ if (!dport) {
+ logeventf(ssh, "Service lookup failed for destination"
+ " port \"%s\"", dports);
+ }
+ }
+ } else {
+ while (*portfwd_strptr) portfwd_strptr++;
+ dport = dserv = -1;
+ portfwd_strptr++; /* eat the NUL and move to next one */
+ }
+ sport = atoi(sports);
+ sserv = 0;
+ if (sport == 0) {
+ sserv = 1;
+ sport = net_service_lookup(sports);
+ if (!sport) {
+ logeventf(ssh, "Service lookup failed for source"
+ " port \"%s\"", sports);
+ }
+ }
+ if (sport && dport) {
+ /* Set up a description of the source port. */
+ struct ssh_portfwd *pfrec, *epfrec;
+
+ pfrec = snew(struct ssh_portfwd);
+ pfrec->type = type;
+ pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
+ pfrec->sserv = sserv ? dupstr(sports) : NULL;
+ pfrec->sport = sport;
+ pfrec->daddr = *host ? dupstr(host) : NULL;
+ pfrec->dserv = dserv ? dupstr(dports) : NULL;
+ pfrec->dport = dport;
+ pfrec->local = NULL;
+ pfrec->remote = NULL;
+ pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
+ address_family == '6' ? ADDRTYPE_IPV6 :
+ ADDRTYPE_UNSPEC);
+
+ epfrec = add234(ssh->portfwds, pfrec);
+ if (epfrec != pfrec) {
+ /*
+ * We already have a port forwarding with precisely
+ * these parameters. Hence, no need to do anything;
+ * simply tag the existing one as KEEP.
+ */
+ epfrec->status = KEEP;
+ free_portfwd(pfrec);
+ } else {
+ pfrec->status = CREATE;
+ }
+ }
+ }
+
+ /*
+ * Now go through and destroy any port forwardings which were
+ * not re-enabled.
+ */
+ for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
+ if (epf->status == DESTROY) {
+ char *message;
+
+ message = dupprintf("%s port forwarding from %s%s%d",
+ epf->type == 'L' ? "local" :
+ epf->type == 'R' ? "remote" : "dynamic",
+ epf->saddr ? epf->saddr : "",
+ epf->saddr ? ":" : "",
+ epf->sport);
+
+ if (epf->type != 'D') {
+ char *msg2 = dupprintf("%s to %s:%d", message,
+ epf->daddr, epf->dport);
+ sfree(message);
+ message = msg2;
+ }
+
+ logeventf(ssh, "Cancelling %s", message);
+ sfree(message);
+
+ if (epf->remote) {
+ struct ssh_rportfwd *rpf = epf->remote;
+ struct Packet *pktout;
+
+ /*
+ * Cancel the port forwarding at the server
+ * end.
+ */
+ if (ssh->version == 1) {
+ /*
+ * We cannot cancel listening ports on the
+ * server side in SSH1! 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
+ * to make on it are rejected.
+ */
+ } else {
+ pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
+ ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
+ ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
+ if (epf->saddr) {
+ ssh2_pkt_addstring(pktout, epf->saddr);
+ } else if (ssh->cfg.rport_acceptall) {
+ ssh2_pkt_addstring(pktout, "0.0.0.0");
+ } else {
+ ssh2_pkt_addstring(pktout, "127.0.0.1");
+ }
+ ssh2_pkt_adduint32(pktout, epf->sport);
+ ssh2_pkt_send(ssh, pktout);
+ }
+
+ del234(ssh->rportfwds, rpf);
+ free_rportfwd(rpf);
+ } else if (epf->local) {
+ pfd_terminate(epf->local);
+ }
+
+ delpos234(ssh->portfwds, i);
+ free_portfwd(epf);
+ i--; /* so we don't skip one in the list */
+ }
+
+ /*
+ * And finally, set up any new port forwardings (status==CREATE).
+ */
+ for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
+ if (epf->status == CREATE) {
+ char *sportdesc, *dportdesc;
+ sportdesc = dupprintf("%s%s%s%s%d%s",
+ epf->saddr ? epf->saddr : "",
+ epf->saddr ? ":" : "",
+ epf->sserv ? epf->sserv : "",
+ epf->sserv ? "(" : "",
+ epf->sport,
+ epf->sserv ? ")" : "");
+ if (epf->type == 'D') {
+ dportdesc = NULL;
+ } else {
+ dportdesc = dupprintf("%s:%s%s%d%s",
+ epf->daddr,
+ epf->dserv ? epf->dserv : "",
+ epf->dserv ? "(" : "",
+ epf->dport,
+ epf->dserv ? ")" : "");
+ }
+
+ if (epf->type == 'L') {
+ const char *err = pfd_addforward(epf->daddr, epf->dport,
+ epf->saddr, epf->sport,
+ ssh, &ssh->cfg,
+ &epf->local,
+ epf->addressfamily);
+
+ logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
+ epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
+ epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
+ sportdesc, dportdesc,
+ err ? " failed: " : "", err ? err : "");
+ } else if (epf->type == 'D') {
+ const char *err = pfd_addforward(NULL, -1,
+ epf->saddr, epf->sport,
+ ssh, &ssh->cfg,
+ &epf->local,
+ epf->addressfamily);
+
+ logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
+ epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
+ epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
+ sportdesc,
+ err ? " failed: " : "", err ? err : "");
+ } else {
+ struct ssh_rportfwd *pf;
+
+ /*
+ * Ensure the remote port forwardings tree exists.
+ */
+ if (!ssh->rportfwds) {
+ if (ssh->version == 1)
+ ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
+ else
+ ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
+ }
+
+ pf = snew(struct ssh_rportfwd);
+ strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
+ pf->dhost[lenof(pf->dhost)-1] = '\0';
+ pf->dport = epf->dport;
+ pf->sport = epf->sport;
+ if (add234(ssh->rportfwds, pf) != pf) {
+ logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
+ epf->daddr, epf->dport);
+ sfree(pf);
+ } else {
+ logeventf(ssh, "Requesting remote port %s"
+ " forward to %s", sportdesc, dportdesc);
+
+ pf->sportdesc = sportdesc;
+ sportdesc = NULL;
+ epf->remote = pf;
+ pf->pfrec = epf;
+
+ if (ssh->version == 1) {
+ send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
+ PKT_INT, epf->sport,
+ PKT_STR, epf->daddr,
+ PKT_INT, epf->dport,
+ PKT_END);
+ ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
+ SSH1_SMSG_FAILURE,
+ ssh_rportfwd_succfail, pf);
+ } else {
+ struct Packet *pktout;
+ pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
+ ssh2_pkt_addstring(pktout, "tcpip-forward");
+ ssh2_pkt_addbool(pktout, 1);/* want reply */
+ if (epf->saddr) {
+ ssh2_pkt_addstring(pktout, epf->saddr);
+ } else if (ssh->cfg.rport_acceptall) {
+ ssh2_pkt_addstring(pktout, "0.0.0.0");
+ } else {
+ ssh2_pkt_addstring(pktout, "127.0.0.1");
+ }
+ ssh2_pkt_adduint32(pktout, epf->sport);
+ ssh2_pkt_send(ssh, pktout);
+
+ ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
+ SSH2_MSG_REQUEST_FAILURE,
+ ssh_rportfwd_succfail, pf);
+ }
+ }
+ }
+ sfree(sportdesc);
+ sfree(dportdesc);
+ }
+}
+
+static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
+{
+ char *string;
+ int stringlen, bufsize;
+
+ ssh_pkt_getstring(pktin, &string, &stringlen);
+ if (string == NULL) {
+ bombout(("Incoming terminal data packet was badly formed"));
+ return;
+ }
+
+ bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
+ string, stringlen);
+ if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
+ ssh->v1_stdout_throttling = 1;
+ ssh1_throttle(ssh, +1);
+ }
+}
+
+static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
+{
+ /* Remote side is trying to open a channel to talk to our
+ * X-Server. Give them back a local channel number. */
+ struct ssh_channel *c;
+ int remoteid = ssh_pkt_getuint32(pktin);
+
+ logevent("Received X11 connect request");
+ /* Refuse if X11 forwarding is disabled. */
+ if (!ssh->X11_fwd_enabled) {
+ send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, remoteid, PKT_END);
+ logevent("Rejected X11 connect request");
+ } else {
+ c = snew(struct ssh_channel);
+ c->ssh = ssh;
+
+ if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
+ ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
+ logevent("Opening X11 forward connection failed");
+ sfree(c);
+ send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, remoteid, PKT_END);
+ } else {
+ logevent
+ ("Opening X11 forward connection succeeded");
+ c->remoteid = remoteid;
+ c->localid = alloc_channel_id(ssh);
+ c->closes = 0;
+ c->v.v1.throttling = 0;
+ c->type = CHAN_X11; /* identify channel type */
+ add234(ssh->channels, c);
+ send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
+ PKT_INT, c->remoteid, PKT_INT,
+ c->localid, PKT_END);
+ logevent("Opened X11 forward channel");
+ }
+ }
+}
+
+static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
+{
+ /* Remote side is trying to open a channel to talk to our
+ * agent. Give them back a local channel number. */
+ struct ssh_channel *c;
+ int remoteid = ssh_pkt_getuint32(pktin);
+
+ /* Refuse if agent forwarding is disabled. */
+ if (!ssh->agentfwd_enabled) {
+ send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, remoteid, PKT_END);
+ } else {
+ c = snew(struct ssh_channel);
+ c->ssh = ssh;
+ c->remoteid = remoteid;
+ c->localid = alloc_channel_id(ssh);
+ c->closes = 0;
+ c->v.v1.throttling = 0;
+ c->type = CHAN_AGENT; /* identify channel type */
+ c->u.a.lensofar = 0;
+ add234(ssh->channels, c);
+ send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
+ PKT_INT, c->remoteid, PKT_INT, c->localid,
+ PKT_END);
+ }
+}
+
+static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
+{
+ /* Remote side is trying to open a channel to talk to a
+ * forwarded port. Give them back a local channel number. */
+ struct ssh_channel *c;
+ struct ssh_rportfwd pf, *pfp;
+ int remoteid;
+ int hostsize, port;
+ char *host, buf[1024];
+ const char *e;
+ c = snew(struct ssh_channel);
+ c->ssh = ssh;
+
+ remoteid = ssh_pkt_getuint32(pktin);
+ ssh_pkt_getstring(pktin, &host, &hostsize);
+ port = ssh_pkt_getuint32(pktin);
+
+ if (hostsize >= lenof(pf.dhost))
+ hostsize = lenof(pf.dhost)-1;
+ memcpy(pf.dhost, host, hostsize);
+ pf.dhost[hostsize] = '\0';
+ pf.dport = port;
+ pfp = find234(ssh->rportfwds, &pf, NULL);
+
+ if (pfp == NULL) {
+ sprintf(buf, "Rejected remote port open request for %s:%d",
+ pf.dhost, port);
+ logevent(buf);
+ send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, remoteid, PKT_END);
+ } else {
+ sprintf(buf, "Received remote port open request for %s:%d",
+ pf.dhost, port);
+ logevent(buf);
+ e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
+ c, &ssh->cfg, pfp->pfrec->addressfamily);
+ if (e != NULL) {
+ char buf[256];
+ sprintf(buf, "Port open failed: %s", e);
+ logevent(buf);
+ sfree(c);
+ send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, remoteid, PKT_END);
+ } else {
+ c->remoteid = remoteid;
+ c->localid = alloc_channel_id(ssh);
+ c->closes = 0;
+ c->v.v1.throttling = 0;
+ c->type = CHAN_SOCKDATA; /* identify channel type */
+ add234(ssh->channels, c);
+ send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
+ PKT_INT, c->remoteid, PKT_INT,
+ c->localid, PKT_END);
+ logevent("Forwarded port opened successfully");
+ }
+ }
+}
+
+static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
+{
+ unsigned int remoteid = ssh_pkt_getuint32(pktin);
+ unsigned int localid = ssh_pkt_getuint32(pktin);
+ struct ssh_channel *c;
+
+ c = find234(ssh->channels, &remoteid, ssh_channelfind);
+ if (c && c->type == CHAN_SOCKDATA_DORMANT) {
+ c->remoteid = localid;
+ c->type = CHAN_SOCKDATA;
+ c->v.v1.throttling = 0;
+ pfd_confirm(c->u.pfd.s);
+ }
+
+ if (c && c->closes) {
+ /*
+ * We have a pending close on this channel,
+ * which we decided on before the server acked
+ * the channel open. So now we know the
+ * remoteid, we can close it again.
+ */
+ send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
+ PKT_INT, c->remoteid, PKT_END);
+ }
+}
+
+static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
+{
+ unsigned int remoteid = ssh_pkt_getuint32(pktin);
+ struct ssh_channel *c;
+
+ c = find234(ssh->channels, &remoteid, ssh_channelfind);
+ if (c && c->type == CHAN_SOCKDATA_DORMANT) {
+ logevent("Forwarded connection refused by server");
+ pfd_close(c->u.pfd.s);
+ del234(ssh->channels, c);
+ sfree(c);
+ }
+}
+
+static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
+{
+ /* Remote side closes a channel. */
+ unsigned i = ssh_pkt_getuint32(pktin);
+ struct ssh_channel *c;
+ c = find234(ssh->channels, &i, ssh_channelfind);
+ if (c && ((int)c->remoteid) != -1) {
+ int closetype;
+ closetype =
+ (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
+
+ if ((c->closes == 0) && (c->type == CHAN_X11)) {
+ logevent("Forwarded X11 connection terminated");
+ assert(c->u.x11.s != NULL);
+ x11_close(c->u.x11.s);
+ c->u.x11.s = NULL;
+ }
+ if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
+ logevent("Forwarded port closed");
+ assert(c->u.pfd.s != NULL);
+ pfd_close(c->u.pfd.s);
+ c->u.pfd.s = NULL;
+ }
+
+ c->closes |= (closetype << 2); /* seen this message */
+ if (!(c->closes & closetype)) {
+ send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
+ PKT_END);
+ c->closes |= closetype; /* sent it too */
+ }
+
+ if (c->closes == 15) {
+ del234(ssh->channels, c);
+ sfree(c);
+ }
+ } else {
+ bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
+ pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
+ "_CONFIRMATION", c ? "half-open" : "nonexistent",
+ i));
+ }
+}
+
+static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
+{
+ /* Data sent down one of our channels. */
+ int i = ssh_pkt_getuint32(pktin);
+ char *p;
+ unsigned int len;
+ struct ssh_channel *c;
+
+ ssh_pkt_getstring(pktin, &p, &len);
+
+ c = find234(ssh->channels, &i, ssh_channelfind);
+ if (c) {
+ int bufsize = 0;
+ switch (c->type) {
+ case CHAN_X11:
+ bufsize = x11_send(c->u.x11.s, p, len);
+ break;
+ case CHAN_SOCKDATA:
+ bufsize = pfd_send(c->u.pfd.s, p, len);
+ break;
+ case CHAN_AGENT:
+ /* Data for an agent message. Buffer it. */
+ while (len > 0) {
+ if (c->u.a.lensofar < 4) {
+ unsigned int l = min(4 - c->u.a.lensofar, len);
+ memcpy(c->u.a.msglen + c->u.a.lensofar, p,
+ l);
+ p += l;
+ len -= l;
+ c->u.a.lensofar += l;
+ }
+ if (c->u.a.lensofar == 4) {
+ c->u.a.totallen =
+ 4 + GET_32BIT(c->u.a.msglen);
+ c->u.a.message = snewn(c->u.a.totallen,
+ unsigned char);
+ memcpy(c->u.a.message, c->u.a.msglen, 4);
+ }
+ if (c->u.a.lensofar >= 4 && len > 0) {
+ unsigned int l =
+ min(c->u.a.totallen - c->u.a.lensofar,
+ len);
+ memcpy(c->u.a.message + c->u.a.lensofar, p,
+ l);
+ p += l;
+ len -= l;
+ c->u.a.lensofar += l;
+ }
+ if (c->u.a.lensofar == c->u.a.totallen) {
+ void *reply;
+ int replylen;
+ if (agent_query(c->u.a.message,
+ c->u.a.totallen,
+ &reply, &replylen,
+ ssh_agentf_callback, c))
+ ssh_agentf_callback(c, reply, replylen);
+ sfree(c->u.a.message);
+ c->u.a.lensofar = 0;
+ }
+ }
+ bufsize = 0; /* agent channels never back up */
+ break;
+ }
+ if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
+ c->v.v1.throttling = 1;
+ ssh1_throttle(ssh, +1);
+ }
+ }
+}
+
+static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
+{
+ char buf[100];
+ ssh->exitcode = ssh_pkt_getuint32(pktin);
+ sprintf(buf, "Server sent command exit status %d",
+ ssh->exitcode);
+ logevent(buf);
+ send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
+ /*
+ * In case `helpful' firewalls or proxies tack
+ * extra human-readable text on the end of the
+ * session which we might mistake for another
+ * encrypted packet, we close the session once
+ * we've sent EXIT_CONFIRMATION.
+ */
+ ssh_closing((Plug)ssh, NULL, 0, 0);
+}
+
+static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
+ struct Packet *pktin)
+{
+ crBegin(ssh->do_ssh1_connection_crstate);
+
+ ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
+ ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
+ ssh1_smsg_stdout_stderr_data;
+
+ ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
+ ssh1_msg_channel_open_confirmation;
+ ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
+ ssh1_msg_channel_open_failure;
+ ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
+ ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
+ ssh1_msg_channel_close;
+ ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
+ ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
+
+ if (ssh->cfg.agentfwd && agent_exists()) {
+ logevent("Requesting agent forwarding");
+ send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
+ do {
+ crReturnV;
+ } while (!pktin);
+ if (pktin->type != SSH1_SMSG_SUCCESS
+ && pktin->type != SSH1_SMSG_FAILURE) {
+ bombout(("Protocol confusion"));
+ crStopV;
+ } else if (pktin->type == SSH1_SMSG_FAILURE) {
+ logevent("Agent forwarding refused");
+ } else {
+ logevent("Agent forwarding enabled");
+ ssh->agentfwd_enabled = TRUE;
+ ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
+ }
+ }
+
+ if (ssh->cfg.x11_forward) {
+ char proto[20], data[64];
+ logevent("Requesting X11 forwarding");
+ ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
+ data, sizeof(data), ssh->cfg.x11_auth);
+ x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
+ if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
+ send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
+ PKT_STR, proto, PKT_STR, data,
+ PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
+ PKT_END);
+ } else {
+ send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
+ PKT_STR, proto, PKT_STR, data, PKT_END);
+ }
+ do {
+ crReturnV;
+ } while (!pktin);
+ if (pktin->type != SSH1_SMSG_SUCCESS
+ && pktin->type != SSH1_SMSG_FAILURE) {
+ bombout(("Protocol confusion"));
+ crStopV;
+ } else if (pktin->type == SSH1_SMSG_FAILURE) {
+ logevent("X11 forwarding refused");
+ } else {
+ logevent("X11 forwarding enabled");
+ ssh->X11_fwd_enabled = TRUE;
+ ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
+ }
+ }
+
+ ssh_setup_portfwd(ssh, &ssh->cfg);
+ ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
+
+ if (!ssh->cfg.nopty) {
+ /* Unpick the terminal-speed string. */
+ /* XXX perhaps we should allow no speeds to be sent. */
+ ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
+ sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
+ /* Send the pty request. */
+ send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
+ PKT_STR, ssh->cfg.termtype,
+ PKT_INT, ssh->term_height,
+ PKT_INT, ssh->term_width,
+ PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
+ PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
+ PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
+ PKT_CHAR, 0, PKT_END);
+ ssh->state = SSH_STATE_INTERMED;
+ do {
+ crReturnV;
+ } while (!pktin);
+ if (pktin->type != SSH1_SMSG_SUCCESS
+ && pktin->type != SSH1_SMSG_FAILURE) {
+ bombout(("Protocol confusion"));
+ crStopV;
+ } else if (pktin->type == SSH1_SMSG_FAILURE) {
+ c_write_str(ssh, "Server refused to allocate pty\r\n");
+ ssh->editing = ssh->echoing = 1;
+ }
+ logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
+ ssh->ospeed, ssh->ispeed);
+ } else {
+ ssh->editing = ssh->echoing = 1;
+ }
+
+ if (ssh->cfg.compression) {
+ send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
+ do {
+ crReturnV;
+ } while (!pktin);
+ if (pktin->type != SSH1_SMSG_SUCCESS
+ && pktin->type != SSH1_SMSG_FAILURE) {
+ bombout(("Protocol confusion"));
+ crStopV;
+ } else if (pktin->type == SSH1_SMSG_FAILURE) {
+ c_write_str(ssh, "Server refused to compress\r\n");
+ }
+ logevent("Started compression");
+ ssh->v1_compressing = TRUE;
+ ssh->cs_comp_ctx = zlib_compress_init();
+ logevent("Initialised zlib (RFC1950) compression");
+ ssh->sc_comp_ctx = zlib_decompress_init();
+ logevent("Initialised zlib (RFC1950) decompression");
+ }
+
+ /*
+ * Start the shell or command.
+ *
+ * Special case: if the first-choice command is an SSH2
+ * subsystem (hence not usable here) and the second choice
+ * exists, we fall straight back to that.
+ */
+ {
+ char *cmd = ssh->cfg.remote_cmd_ptr;
+
+ if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
+ cmd = ssh->cfg.remote_cmd_ptr2;
+ ssh->fallback_cmd = TRUE;
+ }
+ if (*cmd)
+ send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
+ else
+ send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
+ logevent("Started session");
+ }
+
+ ssh->state = SSH_STATE_SESSION;
+ if (ssh->size_needed)
+ ssh_size(ssh, ssh->term_width, ssh->term_height);
+ if (ssh->eof_needed)
+ ssh_special(ssh, TS_EOF);
+
+ if (ssh->ldisc)
+ ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
+ ssh->send_ok = 1;
+ ssh->channels = newtree234(ssh_channelcmp);
+ while (1) {
+
+ /*
+ * By this point, most incoming packets are already being
+ * handled by the dispatch table, and we need only pay
+ * attention to the unusual ones.
+ */
+
+ crReturnV;
+ if (pktin) {
+ if (pktin->type == SSH1_SMSG_SUCCESS) {
+ /* may be from EXEC_SHELL on some servers */
+ } else if (pktin->type == SSH1_SMSG_FAILURE) {
+ /* may be from EXEC_SHELL on some servers
+ * if no pty is available or in other odd cases. Ignore */
+ } else {
+ bombout(("Strange packet received: type %d", pktin->type));
+ crStopV;
+ }
+ } else {
+ while (inlen > 0) {
+ int len = min(inlen, 512);
+ send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
+ PKT_INT, len, PKT_DATA, in, len,
+ PKTT_OTHER, PKT_END);
+ in += len;
+ inlen -= len;
+ }
+ }
+ }
+
+ crFinishV;
+}
+
+/*
+ * Handle the top-level SSH2 protocol.
+ */
+static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
+{
+ char *buf, *msg;
+ int msglen;
+
+ ssh_pkt_getstring(pktin, &msg, &msglen);
+ buf = dupprintf("Remote debug message: %.*s", msglen, msg);
+ logevent(buf);
+ sfree(buf);
+}
+
+static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
+{
+ /* log reason code in disconnect message */
+ char *msg;
+ int msglen;
+
+ ssh_pkt_getstring(pktin, &msg, &msglen);
+ bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
+}
+
+void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
+{
+ /* Do nothing, because we're ignoring it! Duhh. */
+}
+
+static void ssh1_protocol_setup(Ssh ssh)
+{
+ int i;
+
+ /*
+ * Most messages are handled by the coroutines.
+ */
+ for (i = 0; i < 256; i++)
+ ssh->packet_dispatch[i] = NULL;
+
+ /*
+ * These special message types we install handlers for.
+ */
+ ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
+ ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
+ ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
+}
+
+static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
+ struct Packet *pktin)
+{
+ if (ssh->state == SSH_STATE_CLOSED)
+ return;
+
+ if (pktin && ssh->packet_dispatch[pktin->type]) {
+ ssh->packet_dispatch[pktin->type](ssh, pktin);
+ return;
+ }
+
+ if (!ssh->protocol_initial_phase_done) {
+ if (do_ssh1_login(ssh, in, inlen, pktin))
+ ssh->protocol_initial_phase_done = TRUE;
+ else
+ return;
+ }
+
+ do_ssh1_connection(ssh, in, inlen, pktin);
+}
+
+/*
+ * Utility routine for decoding comma-separated strings in KEXINIT.
+ */
+static int in_commasep_string(char *needle, char *haystack, int haylen)
+{
+ int needlen;
+ if (!needle || !haystack) /* protect against null pointers */
+ return 0;
+ needlen = strlen(needle);
+ while (1) {
+ /*
+ * Is it at the start of the string?
+ */
+ if (haylen >= needlen && /* haystack is long enough */
+ !memcmp(needle, haystack, needlen) && /* initial match */
+ (haylen == needlen || haystack[needlen] == ',')
+ /* either , or EOS follows */
+ )
+ return 1;
+ /*
+ * If not, search for the next comma and resume after that.
+ * If no comma found, terminate.
+ */
+ while (haylen > 0 && *haystack != ',')
+ haylen--, haystack++;
+ if (haylen == 0)
+ return 0;
+ haylen--, haystack++; /* skip over comma itself */
+ }
+}
+
+/*
+ * SSH2 key creation method.
+ */
+static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
+ unsigned char *sessid, char chr,
+ unsigned char *keyspace)
+{
+ SHA_State s;
+ /* First 20 bytes. */
+ SHA_Init(&s);
+ if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
+ sha_mpint(&s, K);
+ SHA_Bytes(&s, H, 20);
+ SHA_Bytes(&s, &chr, 1);
+ SHA_Bytes(&s, sessid, 20);
+ SHA_Final(&s, keyspace);
+ /* Next 20 bytes. */
+ SHA_Init(&s);
+ if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
+ sha_mpint(&s, K);
+ SHA_Bytes(&s, H, 20);
+ SHA_Bytes(&s, keyspace, 20);
+ SHA_Final(&s, keyspace + 20);
+}
+
+/*
+ * Handle the SSH2 transport layer.
+ */
+static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
+ struct Packet *pktin)
+{
+ struct do_ssh2_transport_state {
+ int nbits, pbits, warn;
+ Bignum p, g, e, f, K;
+ int kex_init_value, kex_reply_value;
+ const struct ssh_mac **maclist;
+ int nmacs;
+ const struct ssh2_cipher *cscipher_tobe;
+ const struct ssh2_cipher *sccipher_tobe;
+ const struct ssh_mac *csmac_tobe;
+ const struct ssh_mac *scmac_tobe;
+ const struct ssh_compress *cscomp_tobe;
+ const struct ssh_compress *sccomp_tobe;
+ char *hostkeydata, *sigdata, *keystr, *fingerprint;
+ int hostkeylen, siglen;
+ void *hkey; /* actual host key */
+ unsigned char exchange_hash[20];
+ int n_preferred_kex;
+ const struct ssh_kex *preferred_kex[KEX_MAX];
+ int n_preferred_ciphers;
+ const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
+ const struct ssh_compress *preferred_comp;
+ int got_session_id, activated_authconn;
+ struct Packet *pktout;
+ };
+ crState(do_ssh2_transport_state);
+
+ crBegin(ssh->do_ssh2_transport_crstate);
+
+ s->cscipher_tobe = s->sccipher_tobe = NULL;
+ s->csmac_tobe = s->scmac_tobe = NULL;
+ s->cscomp_tobe = s->sccomp_tobe = NULL;
+
+ s->got_session_id = s->activated_authconn = FALSE;
+
+ /*
+ * Be prepared to work around the buggy MAC problem.
+ */
+ if (ssh->remote_bugs & BUG_SSH2_HMAC)
+ s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
+ else
+ s->maclist = macs, s->nmacs = lenof(macs);
+
+ begin_key_exchange:
+ {
+ int i, j, commalist_started;
+
+ /*
+ * Set up the preferred key exchange. (NULL => warn below here)
+ */
+ s->n_preferred_kex = 0;
+ for (i = 0; i < KEX_MAX; i++) {
+ switch (ssh->cfg.ssh_kexlist[i]) {
+ case KEX_DHGEX:
+ s->preferred_kex[s->n_preferred_kex++] =
+ &ssh_diffiehellman_gex;
+ break;
+ case KEX_DHGROUP14:
+ s->preferred_kex[s->n_preferred_kex++] =
+ &ssh_diffiehellman_group14;
+ break;
+ case KEX_DHGROUP1:
+ s->preferred_kex[s->n_preferred_kex++] =
+ &ssh_diffiehellman_group1;
+ break;
+ case CIPHER_WARN:
+ /* Flag for later. Don't bother if it's the last in
+ * the list. */
+ if (i < KEX_MAX - 1) {
+ s->preferred_kex[s->n_preferred_kex++] = NULL;
+ }
+ break;
+ }
+ }
+
+ /*
+ * Set up the preferred ciphers. (NULL => warn below here)
+ */
+ s->n_preferred_ciphers = 0;
+ for (i = 0; i < CIPHER_MAX; i++) {
+ switch (ssh->cfg.ssh_cipherlist[i]) {
+ case CIPHER_BLOWFISH:
+ s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
+ break;
+ case CIPHER_DES:
+ if (ssh->cfg.ssh2_des_cbc) {
+ s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
+ }
+ break;
+ case CIPHER_3DES:
+ s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
+ break;
+ case CIPHER_AES:
+ s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
+ break;
+ case CIPHER_WARN:
+ /* Flag for later. Don't bother if it's the last in
+ * the list. */
+ if (i < CIPHER_MAX - 1) {
+ s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
+ }
+ break;
+ }
+ }
+
+ /*
+ * Set up preferred compression.
+ */
+ if (ssh->cfg.compression)
+ s->preferred_comp = &ssh_zlib;
+ else
+ s->preferred_comp = &ssh_comp_none;
+
+ /*
+ * Enable queueing of outgoing auth- or connection-layer
+ * packets while we are in the middle of a key exchange.
+ */
+ ssh->queueing = TRUE;
+
+ /*
+ * Flag that KEX is in progress.
+ */
+ ssh->kex_in_progress = TRUE;
+
+ /*
+ * Construct and send our key exchange packet.
+ */
+ s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
+ for (i = 0; i < 16; i++)
+ ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
+ /* List key exchange algorithms. */
+ ssh2_pkt_addstring_start(s->pktout);
+ commalist_started = 0;
+ for (i = 0; i < s->n_preferred_kex; i++) {
+ const struct ssh_kex *k = s->preferred_kex[i];
+ if (!k) continue; /* warning flag */
+ if (commalist_started)
+ ssh2_pkt_addstring_str(s->pktout, ",");
+ ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
+ commalist_started = 1;
+ }
+ /* List server host key algorithms. */
+ ssh2_pkt_addstring_start(s->pktout);
+ for (i = 0; i < lenof(hostkey_algs); i++) {
+ ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
+ if (i < lenof(hostkey_algs) - 1)
+ ssh2_pkt_addstring_str(s->pktout, ",");
+ }
+ /* List client->server encryption algorithms. */
+ ssh2_pkt_addstring_start(s->pktout);
+ commalist_started = 0;
+ for (i = 0; i < s->n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = s->preferred_ciphers[i];
+ if (!c) continue; /* warning flag */
+ for (j = 0; j < c->nciphers; j++) {
+ if (commalist_started)
+ ssh2_pkt_addstring_str(s->pktout, ",");
+ ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
+ commalist_started = 1;
+ }
+ }
+ /* List server->client encryption algorithms. */
+ ssh2_pkt_addstring_start(s->pktout);
+ commalist_started = 0;
+ for (i = 0; i < s->n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = s->preferred_ciphers[i];
+ if (!c) continue; /* warning flag */
+ for (j = 0; j < c->nciphers; j++) {
+ if (commalist_started)
+ ssh2_pkt_addstring_str(s->pktout, ",");
+ ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
+ commalist_started = 1;
+ }
+ }
+ /* List client->server MAC algorithms. */
+ ssh2_pkt_addstring_start(s->pktout);
+ for (i = 0; i < s->nmacs; i++) {
+ ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
+ if (i < s->nmacs - 1)
+ ssh2_pkt_addstring_str(s->pktout, ",");
+ }
+ /* List server->client MAC algorithms. */
+ ssh2_pkt_addstring_start(s->pktout);
+ for (i = 0; i < s->nmacs; i++) {
+ ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
+ 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) {
+ ssh2_pkt_addstring_str(s->pktout, ",");
+ ssh2_pkt_addstring_str(s->pktout, c->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);
+ }
+ }
+ /* List client->server languages. Empty list. */
+ ssh2_pkt_addstring_start(s->pktout);
+ /* List server->client languages. Empty list. */
+ ssh2_pkt_addstring_start(s->pktout);
+ /* First KEX packet does _not_ follow, because we're not that brave. */
+ ssh2_pkt_addbool(s->pktout, FALSE);
+ /* Reserved. */
+ ssh2_pkt_adduint32(s->pktout, 0);
+ }
+
+ ssh->exhash = ssh->exhashbase;
+ sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
+
+ ssh2_pkt_send_noqueue(ssh, s->pktout);
+
+ if (!pktin)
+ crWaitUntil(pktin);
+ if (pktin->length > 5)
+ sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
+
+ /*
+ * Now examine the other side's KEXINIT to see what we're up
+ * to.
+ */
+ {
+ char *str;
+ int i, j, len;
+
+ if (pktin->type != SSH2_MSG_KEXINIT) {
+ bombout(("expected key exchange packet from server"));
+ crStop(0);
+ }
+ ssh->kex = NULL;
+ ssh->hostkey = NULL;
+ s->cscipher_tobe = NULL;
+ s->sccipher_tobe = NULL;
+ s->csmac_tobe = NULL;
+ s->scmac_tobe = NULL;
+ s->cscomp_tobe = NULL;
+ s->sccomp_tobe = NULL;
+ pktin->savedpos += 16; /* skip garbage cookie */
+ ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
+ s->warn = 0;
+ 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;
+ }
+ if (ssh->kex) {
+ if (s->warn)
+ askalg(ssh->frontend, "key-exchange algorithm",
+ ssh->kex->name);
+ break;
+ }
+ }
+ if (!ssh->kex) {
+ bombout(("Couldn't agree a key exchange algorithm (available: %s)",
+ str ? str : "(null)"));
+ crStop(0);
+ }
+ 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)) {
+ ssh->hostkey = hostkey_algs[i];
+ break;
+ }
+ }
+ 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;
+ } else {
+ for (j = 0; j < c->nciphers; j++) {
+ if (in_commasep_string(c->list[j]->name, str, len)) {
+ s->cscipher_tobe = c->list[j];
+ break;
+ }
+ }
+ }
+ if (s->cscipher_tobe) {
+ if (s->warn)
+ askalg(ssh->frontend, "client-to-server cipher",
+ s->cscipher_tobe->name);
+ break;
+ }
+ }
+ if (!s->cscipher_tobe) {
+ bombout(("Couldn't agree a client-to-server cipher (available: %s)",
+ str ? str : "(null)"));
+ crStop(0);
+ }
+
+ 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;
+ } else {
+ for (j = 0; j < c->nciphers; j++) {
+ if (in_commasep_string(c->list[j]->name, str, len)) {
+ s->sccipher_tobe = c->list[j];
+ break;
+ }
+ }
+ }
+ if (s->sccipher_tobe) {
+ if (s->warn)
+ askalg(ssh->frontend, "server-to-client cipher",
+ s->sccipher_tobe->name);
+ break;
+ }
+ }
+ if (!s->sccipher_tobe) {
+ bombout(("Couldn't agree a server-to-client cipher (available: %s)",
+ str ? str : "(null)"));
+ crStop(0);
+ }
+
+ ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
+ for (i = 0; i < s->nmacs; i++) {
+ if (in_commasep_string(s->maclist[i]->name, str, len)) {
+ s->csmac_tobe = s->maclist[i];
+ break;
+ }
+ }
+ ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
+ for (i = 0; i < s->nmacs; i++) {
+ if (in_commasep_string(s->maclist[i]->name, str, len)) {
+ s->scmac_tobe = s->maclist[i];
+ break;
+ }
+ }
+ ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
+ for (i = 0; i < lenof(compressions) + 1; i++) {
+ const struct ssh_compress *c =
+ i == 0 ? s->preferred_comp : compressions[i - 1];
+ if (in_commasep_string(c->name, str, len)) {
+ s->cscomp_tobe = c;
+ break;
+ }
+ }
+ ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
+ for (i = 0; i < lenof(compressions) + 1; i++) {
+ const struct ssh_compress *c =
+ i == 0 ? s->preferred_comp : compressions[i - 1];
+ if (in_commasep_string(c->name, str, len)) {
+ s->sccomp_tobe = c;
+ break;
+ }
+ }
+ }
+
+ /*
+ * Work out the number of bits of key we will need from the key
+ * exchange. We start with the maximum key length of either
+ * cipher...
+ */
+ {
+ int csbits, scbits;
+
+ csbits = s->cscipher_tobe->keylen;
+ scbits = s->sccipher_tobe->keylen;
+ s->nbits = (csbits > scbits ? csbits : scbits);
+ }
+ /* The keys only have 160-bit entropy, since they're based on
+ * a SHA-1 hash. So cap the key size at 160 bits. */
+ if (s->nbits > 160)
+ s->nbits = 160;
+
+ /*
+ * If we're doing Diffie-Hellman group exchange, start by
+ * requesting a group.
+ */
+ if (!ssh->kex->pdata) {
+ logevent("Doing Diffie-Hellman group exchange");
+ ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
+ /*
+ * Work out how big a DH group we will need to allow that
+ * much data.
+ */
+ s->pbits = 512 << ((s->nbits - 1) / 64);
+ s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
+ ssh2_pkt_adduint32(s->pktout, s->pbits);
+ ssh2_pkt_send_noqueue(ssh, s->pktout);
+
+ crWaitUntil(pktin);
+ if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
+ bombout(("expected key exchange group packet from server"));
+ crStop(0);
+ }
+ s->p = ssh2_pkt_getmp(pktin);
+ s->g = ssh2_pkt_getmp(pktin);
+ if (!s->p || !s->g) {
+ bombout(("unable to read mp-ints from incoming group packet"));
+ crStop(0);
+ }
+ ssh->kex_ctx = dh_setup_gex(s->p, s->g);
+ s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
+ s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
+ } else {
+ ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
+ ssh->kex_ctx = dh_setup_group(ssh->kex);
+ s->kex_init_value = SSH2_MSG_KEXDH_INIT;
+ s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
+ logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
+ ssh->kex->groupname);
+ }
+
+ logevent("Doing Diffie-Hellman key exchange");
+ /*
+ * Now generate and send e for Diffie-Hellman.
+ */
+ 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);
+
+ crWaitUntil(pktin);
+ if (pktin->type != s->kex_reply_value) {
+ bombout(("expected key exchange reply packet from server"));
+ crStop(0);
+ }
+ ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
+ s->f = ssh2_pkt_getmp(pktin);
+ if (!s->f) {
+ bombout(("unable to parse key exchange reply packet"));
+ crStop(0);
+ }
+ ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
+
+ s->K = dh_find_K(ssh->kex_ctx, s->f);
+
+ sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
+ if (ssh->kex == &ssh_diffiehellman_gex) {
+ sha_uint32(&ssh->exhash, s->pbits);
+ sha_mpint(&ssh->exhash, s->p);
+ sha_mpint(&ssh->exhash, s->g);
+ }
+ sha_mpint(&ssh->exhash, s->e);
+ sha_mpint(&ssh->exhash, s->f);
+ sha_mpint(&ssh->exhash, s->K);
+ SHA_Final(&ssh->exhash, s->exchange_hash);
+
+ dh_cleanup(ssh->kex_ctx);
+ ssh->kex_ctx = NULL;
+
+#if 0
+ debug(("Exchange hash is:\n"));
+ dmemdump(s->exchange_hash, 20);
+#endif
+
+ s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
+ if (!s->hkey ||
+ !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
+ (char *)s->exchange_hash, 20)) {
+ bombout(("Server's host key did not match the signature supplied"));
+ crStop(0);
+ }
+
+ /*
+ * Authenticate remote host: verify host key. (We've already
+ * checked the signature of the exchange hash.)
+ */
+ s->keystr = ssh->hostkey->fmtkey(s->hkey);
+ s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
+ verify_ssh_host_key(ssh->frontend,
+ ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
+ s->keystr, s->fingerprint);
+ if (!s->got_session_id) { /* don't bother logging this in rekeys */
+ logevent("Host key fingerprint is:");
+ logevent(s->fingerprint);
+ }
+ sfree(s->fingerprint);
+ sfree(s->keystr);
+ ssh->hostkey->freekey(s->hkey);
+
+ /*
+ * The exchange hash from the very first key exchange is also
+ * the session id, used in session key construction and
+ * authentication.
+ */
+ if (!s->got_session_id) {
+ memcpy(ssh->v2_session_id, s->exchange_hash,
+ sizeof(s->exchange_hash));
+ s->got_session_id = TRUE;
+ }
+
+ /*
+ * Send SSH2_MSG_NEWKEYS.
+ */
+ s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
+ ssh2_pkt_send_noqueue(ssh, s->pktout);
+ ssh->outgoing_data_size = 0; /* start counting from here */
+
+ /*
+ * We've sent client NEWKEYS, so create and initialise
+ * client-to-server session keys.
+ */
+ if (ssh->cs_cipher_ctx)
+ ssh->cscipher->free_context(ssh->cs_cipher_ctx);
+ ssh->cscipher = s->cscipher_tobe;
+ ssh->cs_cipher_ctx = ssh->cscipher->make_context();
+
+ if (ssh->cs_mac_ctx)
+ ssh->csmac->free_context(ssh->cs_mac_ctx);
+ ssh->csmac = s->csmac_tobe;
+ ssh->cs_mac_ctx = ssh->csmac->make_context();
+
+ if (ssh->cs_comp_ctx)
+ ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
+ ssh->cscomp = s->cscomp_tobe;
+ ssh->cs_comp_ctx = ssh->cscomp->compress_init();
+
+ /*
+ * Set IVs on client-to-server keys. Here we use the exchange
+ * hash from the _first_ key exchange.
+ */
+ {
+ unsigned char keyspace[40];
+ ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
+ ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
+ ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
+ ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
+ ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
+ ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
+ }
+
+ logeventf(ssh, "Initialised %.200s client->server encryption",
+ ssh->cscipher->text_name);
+ logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
+ ssh->csmac->text_name);
+ if (ssh->cscomp->text_name)
+ logeventf(ssh, "Initialised %s compression",
+ ssh->cscomp->text_name);