#define BUG_CHOKES_ON_RSA 8
#define BUG_SSH2_RSA_PADDING 16
#define BUG_SSH2_DERIVEKEY 32
-/* 64 was BUG_SSH2_DH_GEX, now spare */
+#define BUG_SSH2_REKEY 64
#define BUG_SSH2_PK_SESSIONID 128
#define translate(x) if (type == x) return #x
#define SSH1_BUFFER_LIMIT 32768
#define SSH_MAX_BACKLOG 32768
#define OUR_V2_WINSIZE 16384
+#define OUR_V2_MAXPKT 0x4000UL
const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
Ssh ssh; /* pointer back to main context */
unsigned remoteid, localid;
int type;
+ /* True if we opened this channel but server hasn't confirmed. */
+ int halfopen;
/*
* In SSH1, this value contains four bits:
*
struct Packet {
long length;
+ long forcepad; /* Force padding to at least this length */
int type;
unsigned long sequence;
unsigned char *data;
struct logblank_t *blanks;
};
-static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
+static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
struct Packet *pktin);
-static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
+static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
struct Packet *pktin);
static void ssh1_protocol_setup(Ssh ssh);
static void ssh2_protocol_setup(Ssh ssh);
static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
static int ssh_sendbuffer(void *handle);
-static void ssh_do_close(Ssh ssh);
+static int ssh_do_close(Ssh ssh, int notify_exit);
static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
static int ssh2_pkt_getbool(struct Packet *pkt);
static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
static void ssh2_timer(void *ctx, long now);
-static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
+static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
struct Packet *pktin);
struct rdpkt1_state_tag {
tree234 *channels; /* indexed by local id */
struct ssh_channel *mainchan; /* primary session channel */
int exitcode;
+ int close_expected;
tree234 *rportfwds, *portfwds;
int overall_bufsize;
int throttled_all;
int v1_stdout_throttling;
- int v2_outgoing_sequence;
+ unsigned long v2_outgoing_sequence;
int ssh1_rdpkt_crstate;
int ssh2_rdpkt_crstate;
/* ssh1 and ssh2 use this for different things, but both use it */
int protocol_initial_phase_done;
- void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
+ void (*protocol) (Ssh ssh, void *vin, int inlen,
struct Packet *pkt);
struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
#define bombout(msg) \
do { \
char *text = dupprintf msg; \
- ssh_do_close(ssh); \
+ ssh_do_close(ssh, FALSE); \
logevent(text); \
connection_fatal(ssh->frontend, "%s", text); \
sfree(text); \
{
struct Packet *pkt = ssh_new_packet();
pkt->length = 5;
+ pkt->forcepad = 0;
ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
return pkt;
}
/*
* Add padding. At least four bytes, and must also bring total
* length (minus MAC) up to a multiple of the block size.
+ * If pkt->forcepad is set, make sure the packet is at least that size
+ * after padding.
*/
cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
padding = 4;
+ if (pkt->length + padding < pkt->forcepad)
+ padding = pkt->forcepad - pkt->length;
padding +=
(cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
+ assert(padding <= 255);
maclen = ssh->csmac ? ssh->csmac->len : 0;
ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
pkt->data[4] = padding;
if (!ssh->kex_in_progress &&
ssh->max_data_size != 0 &&
ssh->outgoing_data_size > ssh->max_data_size)
- do_ssh2_transport(ssh, "Initiating key re-exchange "
- "(too much data sent)", -1, NULL);
+ do_ssh2_transport(ssh, "too much data sent", -1, NULL);
ssh_free_packet(pkt);
}
ssh2_pkt_send_noqueue(ssh, pkt);
}
+#if 0 /* disused */
/*
* Either queue or defer a packet, depending on whether queueing is
* set.
else
ssh2_pkt_defer_noqueue(ssh, pkt);
}
+#endif
/*
* Send the whole deferred data block constructed by
if (!ssh->kex_in_progress &&
ssh->max_data_size != 0 &&
ssh->outgoing_data_size > ssh->max_data_size)
- do_ssh2_transport(ssh, "Initiating key re-exchange "
- "(too much data sent)", -1, NULL);
+ do_ssh2_transport(ssh, "too much data sent", -1, NULL);
ssh->deferred_data_size = 0;
}
ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
logevent("We believe remote version has SSH2 public-key-session-ID bug");
}
+
+ if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
+ (ssh->cfg.sshbug_rekey2 == AUTO &&
+ (wc_match("OpenSSH_2.[0-4]*", imp) ||
+ wc_match("OpenSSH_2.5.[0-3]*", imp) ||
+ wc_match("Sun_SSH_1.0", imp) ||
+ wc_match("Sun_SSH_1.0.1", imp)))) {
+ /*
+ * These versions have the SSH2 rekey bug.
+ */
+ ssh->remote_bugs |= BUG_SSH2_REKEY;
+ logevent("We believe remote version has SSH2 rekey bug");
+ }
}
/*
s->vstring[s->vslen] = 0;
s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
- {
- char *vlog;
- vlog = snewn(20 + s->vslen, char);
- sprintf(vlog, "Server version: %s", s->vstring);
- logevent(vlog);
- sfree(vlog);
- }
+ logeventf(ssh, "Server version: %s", s->vstring);
ssh_detect_bugs(ssh, s->vstring);
/*
crFinishV;
}
-static void ssh_do_close(Ssh ssh)
+static int ssh_do_close(Ssh ssh, int notify_exit)
{
- int i;
+ int i, ret = 0;
struct ssh_channel *c;
ssh->state = SSH_STATE_CLOSED;
if (ssh->s) {
sk_close(ssh->s);
ssh->s = NULL;
- notify_remote_exit(ssh->frontend);
+ if (notify_exit)
+ notify_remote_exit(ssh->frontend);
+ else
+ ret = 1;
}
/*
* Now we must shut down any port and X forwardings going
sfree(c);
}
}
+
+ return ret;
+}
+
+static void ssh_log(Plug plug, int type, SockAddr addr, int port,
+ const char *error_msg, int error_code)
+{
+ Ssh ssh = (Ssh) plug;
+ char addrbuf[256], *msg;
+
+ sk_getaddr(addr, addrbuf, lenof(addrbuf));
+
+ if (type == 0)
+ msg = dupprintf("Connecting to %s port %d", addrbuf, port);
+ else
+ msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
+
+ logevent(msg);
+ sfree(msg);
}
static int ssh_closing(Plug plug, const char *error_msg, int error_code,
int calling_back)
{
Ssh ssh = (Ssh) plug;
- ssh_do_close(ssh);
+ int need_notify = ssh_do_close(ssh, FALSE);
+
+ if (!error_msg && !ssh->close_expected) {
+ error_msg = "Server unexpectedly closed network connection";
+ }
+
if (error_msg) {
/* A socket error has occurred. */
logevent(error_msg);
connection_fatal(ssh->frontend, "%s", error_msg);
} else {
- /* Otherwise, the remote side closed the connection normally. */
+ logevent("Server closed network connection");
}
+ if (need_notify)
+ notify_remote_exit(ssh->frontend);
return 0;
}
Ssh ssh = (Ssh) plug;
ssh_gotdata(ssh, (unsigned char *)data, len);
if (ssh->state == SSH_STATE_CLOSED) {
- ssh_do_close(ssh);
+ ssh_do_close(ssh, TRUE);
return 0;
}
return 1;
char **realhost, int nodelay, int keepalive)
{
static const struct plug_function_table fn_table = {
+ ssh_log,
ssh_closing,
ssh_receive,
ssh_sent,
/*
* Open socket.
*/
- {
- char addrbuf[100];
- sk_getaddr(addr, addrbuf, 100);
- logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
- }
ssh->fn = &fn_table;
ssh->s = new_connection(addr, *realhost, port,
0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
* Terminate.
*/
logevent("No username provided. Abandoning session.");
+ ssh->close_expected = TRUE;
ssh_closing((Plug)ssh, NULL, 0, 0);
crStop(1);
}
s->p = s->response + 5;
s->nkeys = GET_32BIT(s->p);
s->p += 4;
- {
- char buf[64];
- sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
- logevent(buf);
- }
+ logeventf(ssh, "Pageant has %d SSH1 keys", s->nkeys);
for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
- {
- char buf[64];
- sprintf(buf, "Trying Pageant key #%d", s->keyi);
- logevent(buf);
- }
+ logeventf(ssh, "Trying Pageant key #%d", s->keyi);
if (s->publickey_blob &&
!memcmp(s->p, s->publickey_blob,
s->publickey_bloblen)) {
if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
char *comment = NULL;
int type;
- char msgbuf[256];
if (flags & FLAG_VERBOSE)
c_write_str(ssh, "Trying public key authentication.\r\n");
logeventf(ssh, "Trying public key \"%s\"",
filename_to_str(&ssh->cfg.keyfile));
type = key_type(&ssh->cfg.keyfile);
if (type != SSH_KEYTYPE_SSH1) {
- sprintf(msgbuf, "Key is of wrong type (%s)",
- key_type_to_str(type));
- logevent(msgbuf);
- c_write_str(ssh, msgbuf);
+ char *msg = dupprintf("Key is of wrong type (%s)",
+ key_type_to_str(type));
+ logevent(msg);
+ c_write_str(ssh, msg);
c_write_str(ssh, "\r\n");
+ sfree(msg);
s->tried_publickey = 1;
continue;
}
PKT_END);
logevent("Unable to authenticate");
connection_fatal(ssh->frontend, "Unable to authenticate");
+ ssh->close_expected = TRUE;
ssh_closing((Plug)ssh, NULL, 0, 0);
crStop(1);
}
if (c && !c->closes) {
/*
- * If the channel's remoteid is -1, we have sent
+ * If halfopen is true, 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 (!c->halfopen) {
if (ssh->version == 1) {
send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
PKT_END);
}
} 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 */
}
if (epf->saddr) {
ssh2_pkt_addstring(pktout, epf->saddr);
} else if (ssh->cfg.rport_acceptall) {
+ /* XXX: ssh->cfg.rport_acceptall may not represent
+ * what was used to open the original connection,
+ * since it's reconfigurable. */
ssh2_pkt_addstring(pktout, "0.0.0.0");
} else {
ssh2_pkt_addstring(pktout, "127.0.0.1");
if (epf->type == 'L') {
const char *err = pfd_addforward(epf->daddr, epf->dport,
epf->saddr, epf->sport,
- ssh, &ssh->cfg,
+ ssh, cfg,
&epf->local,
epf->addressfamily);
} else if (epf->type == 'D') {
const char *err = pfd_addforward(NULL, -1,
epf->saddr, epf->sport,
- ssh, &ssh->cfg,
+ ssh, cfg,
&epf->local,
epf->addressfamily);
ssh2_pkt_addbool(pktout, 1);/* want reply */
if (epf->saddr) {
ssh2_pkt_addstring(pktout, epf->saddr);
- } else if (ssh->cfg.rport_acceptall) {
+ } else if (cfg->rport_acceptall) {
ssh2_pkt_addstring(pktout, "0.0.0.0");
} else {
ssh2_pkt_addstring(pktout, "127.0.0.1");
logevent
("Opening X11 forward connection succeeded");
c->remoteid = remoteid;
+ c->halfopen = FALSE;
c->localid = alloc_channel_id(ssh);
c->closes = 0;
c->v.v1.throttling = 0;
c = snew(struct ssh_channel);
c->ssh = ssh;
c->remoteid = remoteid;
+ c->halfopen = FALSE;
c->localid = alloc_channel_id(ssh);
c->closes = 0;
c->v.v1.throttling = 0;
struct ssh_rportfwd pf, *pfp;
int remoteid;
int hostsize, port;
- char *host, buf[1024];
+ char *host;
const char *e;
c = snew(struct ssh_channel);
c->ssh = ssh;
pfp = find234(ssh->rportfwds, &pf, NULL);
if (pfp == NULL) {
- sprintf(buf, "Rejected remote port open request for %s:%d",
- pf.dhost, port);
- logevent(buf);
+ logeventf(ssh, "Rejected remote port open request for %s:%d",
+ pf.dhost, port);
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);
+ logeventf(ssh, "Received remote port open request for %s:%d",
+ pf.dhost, port);
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);
+ logeventf(ssh, "Port open failed: %s", e);
sfree(c);
send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
PKT_INT, remoteid, PKT_END);
} else {
c->remoteid = remoteid;
+ c->halfopen = FALSE;
c->localid = alloc_channel_id(ssh);
c->closes = 0;
c->v.v1.throttling = 0;
c = find234(ssh->channels, &remoteid, ssh_channelfind);
if (c && c->type == CHAN_SOCKDATA_DORMANT) {
c->remoteid = localid;
+ c->halfopen = FALSE;
c->type = CHAN_SOCKDATA;
c->v.v1.throttling = 0;
pfd_confirm(c->u.pfd.s);
unsigned i = ssh_pkt_getuint32(pktin);
struct ssh_channel *c;
c = find234(ssh->channels, &i, ssh_channelfind);
- if (c && ((int)c->remoteid) != -1) {
+ if (c && !c->halfopen) {
int closetype;
closetype =
(pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
/* Data sent down one of our channels. */
int i = ssh_pkt_getuint32(pktin);
char *p;
- unsigned int len;
+ int len;
struct ssh_channel *c;
ssh_pkt_getstring(pktin, &p, &len);
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);
+ logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
/*
* In case `helpful' firewalls or proxies tack
* encrypted packet, we close the session once
* we've sent EXIT_CONFIRMATION.
*/
+ ssh->close_expected = TRUE;
ssh_closing((Plug)ssh, NULL, 0, 0);
}
*/
static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
{
- char *buf, *msg;
+ char *msg;
int msglen;
ssh_pkt_getstring(pktin, &msg, &msglen);
- buf = dupprintf("Remote debug message: %.*s", msglen, msg);
- logevent(buf);
- sfree(buf);
+ logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
}
static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
}
-void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
+static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
{
/* Do nothing, because we're ignoring it! Duhh. */
}
ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
}
-static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
+static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
struct Packet *pktin)
{
+ unsigned char *in=(unsigned char*)vin;
if (ssh->state == SSH_STATE_CLOSED)
return;
}
/*
+ * Similar routine for checking whether we have the first string in a list.
+ */
+static int first_in_commasep_string(char *needle, char *haystack, int haylen)
+{
+ int needlen;
+ if (!needle || !haystack) /* protect against null pointers */
+ return 0;
+ needlen = strlen(needle);
+ /*
+ * 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;
+ return 0;
+}
+
+
+/*
* SSH2 key creation method.
*/
static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
/*
* Handle the SSH2 transport layer.
*/
-static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
+static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
struct Packet *pktin)
{
+ unsigned char *in = (unsigned char *)vin;
struct do_ssh2_transport_state {
int nbits, pbits, warn;
Bignum p, g, e, f, K;
*/
{
char *str;
- int i, j, len;
+ int i, j, len, guessok;
if (pktin->type != SSH2_MSG_KEXINIT) {
bombout(("expected key exchange packet from server"));
str ? str : "(null)"));
crStop(0);
}
+ /*
+ * Note that the server's guess is considered wrong if it doesn't match
+ * 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);
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 &&
+ 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++) {
break;
}
}
+ 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 */
+ 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);
*/
while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
(!pktin && inlen == -1))) {
+ wait_for_rekey:
crReturn(1);
}
if (pktin) {
logevent("Server initiated key re-exchange");
} else {
- logevent((char *)in);
+ /*
+ * 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,
+ * we process it anyway!)
+ */
+ if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
+ logeventf(ssh, "Server bug prevents key re-exchange (%s)",
+ (char *)in);
+ /* Reset the counters, so that at least this message doesn't
+ * hit the event log _too_ often. */
+ ssh->outgoing_data_size = 0;
+ ssh->incoming_data_size = 0;
+ if (ssh->cfg.ssh_rekey_time != 0) {
+ ssh->next_rekey =
+ schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
+ ssh2_timer, ssh);
+ }
+ goto wait_for_rekey; /* this is utterly horrid */
+ } else {
+ logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
+ }
}
goto begin_key_exchange;
if (c->closes != 0)
return;
- if (newwin > c->v.v2.locwindow) {
+ /*
+ * Only send a WINDOW_ADJUST if there's significantly more window
+ * available than the other end thinks there is. This saves us
+ * sending a WINDOW_ADJUST for every character in a shell session.
+ *
+ * "Significant" is arbitrarily defined as half the window size.
+ */
+ if (newwin > c->v.v2.locwindow * 2) {
struct Packet *pktout;
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
{
char *data;
- unsigned int length;
+ int length;
unsigned i = ssh_pkt_getuint32(pktin);
struct ssh_channel *c;
c = find234(ssh->channels, &i, ssh_channelfind);
struct Packet *pktout;
c = find234(ssh->channels, &i, ssh_channelfind);
- if (!c || ((int)c->remoteid) == -1) {
+ if (!c || c->halfopen) {
bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
c ? "half-open" : "nonexistent", i));
return;
ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
ssh2_pkt_send_noqueue(ssh, s->pktout);
#endif
+ ssh->close_expected = TRUE;
ssh_closing((Plug)ssh, NULL, 0, 0);
}
}
if (c->type != CHAN_SOCKDATA_DORMANT)
return; /* dunno why they're confirming this */
c->remoteid = ssh_pkt_getuint32(pktin);
+ c->halfopen = FALSE;
c->type = CHAN_SOCKDATA;
c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
unsigned reason_code;
char *reason_string;
int reason_length;
- char *message;
struct ssh_channel *c;
c = find234(ssh->channels, &i, ssh_channelfind);
if (!c)
if (reason_code >= lenof(reasons))
reason_code = 0; /* ensure reasons[reason_code] in range */
ssh_pkt_getstring(pktin, &reason_string, &reason_length);
- message = dupprintf("Forwarded connection refused by"
- " server: %s [%.*s]", reasons[reason_code],
- reason_length, reason_string);
- logevent(message);
- sfree(message);
+ logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
+ reasons[reason_code], reason_length, reason_string);
pfd_close(c->u.pfd.s);
ssh2_pkt_addstring(pktout, "en"); /* language tag */
ssh2_pkt_send_noqueue(ssh, pktout);
connection_fatal(ssh->frontend, "%s", buf);
+ ssh->close_expected = TRUE;
ssh_closing((Plug)ssh, NULL, 0, 0);
return;
}
if (q >= 0 && q+4 <= len) { \
q = q + 4 + GET_32BIT(p+q); \
if (q >= 0 && q+4 <= len && \
- (q = q + 4 + GET_32BIT(p+q)) && q == len) \
+ ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
result = TRUE; \
} \
} while(0)
}
c->remoteid = remid;
+ c->halfopen = FALSE;
if (error) {
pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
ssh2_pkt_adduint32(pktout, c->remoteid);
ssh2_pkt_adduint32(pktout, c->remoteid);
ssh2_pkt_adduint32(pktout, c->localid);
ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
- ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
+ ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ssh2_pkt_send(ssh, pktout);
}
}
* Terminate.
*/
logevent("No username provided. Abandoning session.");
+ ssh->close_expected = TRUE;
ssh_closing((Plug)ssh, NULL, 0, 0);
crStopV;
}
s->p = s->response + 5;
s->nkeys = GET_32BIT(s->p);
s->p += 4;
- {
- char buf[64];
- sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
- logevent(buf);
- }
+ logeventf(ssh, "Pageant has %d SSH2 keys", s->nkeys);
for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
void *vret;
- {
- char buf[64];
- sprintf(buf, "Trying Pageant key #%d", s->keyi);
- logevent(buf);
- }
+ logeventf(ssh, "Trying Pageant key #%d", s->keyi);
s->pklen = GET_32BIT(s->p);
s->p += 4;
if (s->publickey_blob &&
logevent("Unable to authenticate");
connection_fatal(ssh->frontend,
"Unable to authenticate");
+ ssh->close_expected = TRUE;
ssh_closing((Plug)ssh, NULL, 0, 0);
crStopV;
}
}
} else if (s->method == AUTH_PASSWORD) {
/*
- * We send the password packet lumped tightly together with
- * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
- * string long enough to make the total length of the two
- * packets constant. This should ensure that a passive
- * listener doing traffic analyis can't work out the length
- * of the password.
+ * We pad out the password packet to 256 bytes to make
+ * it harder for an attacker to find the length of the
+ * user's password.
*
- * For this to work, we need an assumption about the
- * maximum length of the password packet. I think 256 is
- * pretty conservative. Anyone using a password longer than
- * that probably doesn't have much to worry about from
+ * Anyone using a password longer than 256 bytes
+ * probably doesn't have much to worry about from
* people who find out how long their password is!
*/
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ s->pktout->forcepad = 256;
ssh2_pkt_addstring(s->pktout, s->username);
ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
ssh2_pkt_addstring(s->pktout, "password");
ssh2_pkt_addstring(s->pktout, s->password);
memset(s->password, 0, sizeof(s->password));
end_log_omission(ssh, s->pktout);
- ssh2_pkt_defer(ssh, s->pktout);
- /*
- * We'll include a string that's an exact multiple of the
- * cipher block size. If the cipher is NULL for some
- * reason, we don't do this trick at all because we gain
- * nothing by it.
- */
- if (ssh->cscipher) {
- int stringlen, i;
-
- stringlen = (256 - ssh->deferred_len);
- stringlen += ssh->cscipher->blksize - 1;
- stringlen -= (stringlen % ssh->cscipher->blksize);
- if (ssh->cscomp) {
- /*
- * Temporarily disable actual compression,
- * so we can guarantee to get this string
- * exactly the length we want it. The
- * compression-disabling routine should
- * return an integer indicating how many
- * bytes we should adjust our string length
- * by.
- */
- stringlen -=
- ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
- }
- s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
- ssh2_pkt_addstring_start(s->pktout);
- for (i = 0; i < stringlen; i++) {
- char c = (char) random_byte();
- ssh2_pkt_addstring_data(s->pktout, &c, 1);
- }
- ssh2_pkt_defer(ssh, s->pktout);
- }
- ssh_pkt_defersend(ssh);
+ ssh2_pkt_send(ssh, s->pktout);
logevent("Sent password");
s->type = AUTH_TYPE_PASSWORD;
} else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
if (s->curr_prompt == 0) {
s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
+ s->pktout->forcepad = 256;
ssh2_pkt_adduint32(s->pktout, s->num_prompts);
}
if (s->need_pw) { /* only add pw if we just got one! */
" methods available");
ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
ssh2_pkt_send_noqueue(ssh, s->pktout);
+ ssh->close_expected = TRUE;
ssh_closing((Plug)ssh, NULL, 0, 0);
crStopV;
}
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
- ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
+ ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ssh2_pkt_send(ssh, s->pktout);
crWaitUntilV(pktin);
if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
crStopV;
}
ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
+ ssh->mainchan->halfopen = FALSE;
ssh->mainchan->type = CHAN_MAINSESSION;
ssh->mainchan->closes = 0;
ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
/*
* Handlers for SSH2 messages that might arrive at any moment.
*/
-void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
+static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
{
/* log reason code in disconnect message */
char *buf, *msg;
sfree(buf);
}
-void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
+static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
{
/* log the debug message */
- char *buf, *msg;
+ char *msg;
int msglen;
int always_display;
always_display = ssh2_pkt_getbool(pktin);
ssh_pkt_getstring(pktin, &msg, &msglen);
- buf = dupprintf("Remote debug message: %.*s", msglen, msg);
- logevent(buf);
- sfree(buf);
+ logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
}
-void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
+static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
{
struct Packet *pktout;
pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
now - ssh->next_rekey >= 0) {
- do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
- -1, NULL);
+ do_ssh2_transport(ssh, "timeout", -1, NULL);
}
}
-static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
+static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
struct Packet *pktin)
{
+ unsigned char *in = (unsigned char *)vin;
if (ssh->state == SSH_STATE_CLOSED)
return;
if (!ssh->kex_in_progress &&
ssh->max_data_size != 0 &&
ssh->incoming_data_size > ssh->max_data_size)
- do_ssh2_transport(ssh, "Initiating key re-exchange "
- "(too much data received)", -1, NULL);
+ do_ssh2_transport(ssh, "too much data received", -1, NULL);
}
if (pktin && ssh->packet_dispatch[pktin->type]) {
ssh->kex_ctx = NULL;
ssh->hostkey = NULL;
ssh->exitcode = -1;
+ ssh->close_expected = FALSE;
ssh->state = SSH_STATE_PREPACKET;
ssh->size_needed = FALSE;
ssh->eof_needed = FALSE;
ssh->crcda_ctx = NULL;
}
if (ssh->s)
- ssh_do_close(ssh);
+ ssh_do_close(ssh, TRUE);
expire_timer_context(ssh);
if (ssh->pinger)
pinger_free(ssh->pinger);
long now = GETTICKCOUNT();
if (new_next - now < 0) {
- rekeying = "Initiating key re-exchange (timeout shortened)";
+ rekeying = "timeout shortened";
} else {
ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
}
ssh->max_data_size != 0) {
if (ssh->outgoing_data_size > ssh->max_data_size ||
ssh->incoming_data_size > ssh->max_data_size)
- rekeying = "Initiating key re-exchange (data limit lowered)";
+ rekeying = "data limit lowered";
}
if (ssh->cfg.compression != cfg->compression) {
- rekeying = "Initiating key re-exchange (compression setting changed)";
+ rekeying = "compression setting changed";
rekey_mandatory = TRUE;
}
if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
sizeof(ssh->cfg.ssh_cipherlist))) {
- rekeying = "Initiating key re-exchange (cipher settings changed)";
+ rekeying = "cipher settings changed";
rekey_mandatory = TRUE;
}
}
} else if (code == TS_REKEY) {
if (!ssh->kex_in_progress && ssh->version == 2) {
- do_ssh2_transport(ssh, "Initiating key re-exchange at"
- " user request", -1, NULL);
+ do_ssh2_transport(ssh, "at user request", -1, NULL);
}
} else if (code == TS_BRK) {
if (ssh->state == SSH_STATE_CLOSED
c->ssh = ssh;
if (c) {
- c->remoteid = -1; /* to be set when open confirmed */
+ c->halfopen = TRUE;
c->localid = alloc_channel_id(ssh);
c->closes = 0;
c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
ssh2_pkt_adduint32(pktout, c->localid);
c->v.v2.locwindow = OUR_V2_WINSIZE;
ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
- ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
+ ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ssh2_pkt_addstring(pktout, hostname);
ssh2_pkt_adduint32(pktout, port);
/*