*/
#define BUG_CHOKES_ON_SSH1_IGNORE 1
#define BUG_SSH2_HMAC 2
+#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
+
#define GET_32BIT(cp) \
(((unsigned long)(unsigned char)(cp)[0] << 24) | \
extern char *x11_init(Socket *, char *, void *);
extern void x11_close(Socket);
-extern void x11_send(Socket, char *, int);
+extern int x11_send(Socket, char *, int);
extern void x11_invent_auth(char *, int, char *, int);
+extern void x11_unthrottle(Socket s);
+extern void x11_override_throttle(Socket s, int enable);
extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
extern char *pfd_addforward(char *desthost, int destport, int port);
extern void pfd_close(Socket s);
-extern void pfd_send(Socket s, char *data, int len);
+extern int pfd_send(Socket s, char *data, int len);
extern void pfd_confirm(Socket s);
+extern void pfd_unthrottle(Socket s);
+extern void pfd_override_throttle(Socket s, int enable);
+
+/*
+ * Buffer management constants. There are several of these for
+ * various different purposes:
+ *
+ * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
+ * on a local data stream before we throttle the whole SSH
+ * connection (in SSH1 only). Throttling the whole connection is
+ * pretty drastic so we set this high in the hope it won't
+ * happen very often.
+ *
+ * - SSH_MAX_BACKLOG is the amount of backlog that must build up
+ * on the SSH connection itself before we defensively throttle
+ * _all_ local data streams. This is pretty drastic too (though
+ * thankfully unlikely in SSH2 since the window mechanism should
+ * ensure that the server never has any need to throttle its end
+ * of the connection), so we set this high as well.
+ *
+ * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
+ * channels.
+ */
+
+#define SSH1_BUFFER_LIMIT 32768
+#define SSH_MAX_BACKLOG 32768
+#define OUR_V2_WINSIZE 16384
/*
- * Ciphers for SSH2. We miss out single-DES because it isn't
- * supported; also 3DES and Blowfish are both done differently from
- * SSH1. (3DES uses outer chaining; Blowfish has the opposite
- * endianness and different-sized keys.)
+ * Ciphers for SSH2.
*/
const static struct ssh2_ciphers *ciphers[] = {
&ssh2_aes,
&ssh2_blowfish,
&ssh2_3des,
+ &ssh2_des,
};
const static struct ssh_kex *kex_algs[] = {
unsigned remoteid, localid;
int type;
int closes;
- struct ssh2_data_channel {
- unsigned char *outbuffer;
- unsigned outbuflen, outbufsize;
- unsigned remwindow, remmaxpkt;
- } v2;
+ union {
+ struct ssh1_data_channel {
+ int throttling;
+ } v1;
+ struct ssh2_data_channel {
+ bufchain outbuffer;
+ unsigned remwindow, remmaxpkt;
+ unsigned locwindow;
+ } v2;
+ } v;
union {
struct ssh_agent_channel {
unsigned char *message;
static unsigned char *deferred_send_data = NULL;
static int deferred_len = 0, deferred_size = 0;
+/*
+ * Gross hack: pscp will try to start SFTP but fall back to scp1 if
+ * that fails. This variable is the means by which scp.c can reach
+ * into the SSH code and find out which one it got.
+ */
+int ssh_fallback_cmd = 0;
+
static int ssh_version;
+static int ssh1_throttle_count;
+static int ssh_overall_bufsize;
+static int ssh_throttled_all;
+static int ssh1_stdout_throttling;
static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
static void ssh_size(void);
static void ssh_special(Telnet_Special);
-static void ssh2_try_send(struct ssh_channel *c);
+static int ssh2_try_send(struct ssh_channel *c);
static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
int len);
-
+static void ssh_throttle_all(int enable, int bufsize);
+static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
static int (*s_rdpkt) (unsigned char **data, int *datalen);
+static int ssh_sendbuffer(void);
static struct rdpkt1_state_tag {
long len, pad, biglen, to_read;
{
struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
- int i;
+
if (a->sport > b->sport)
return +1;
if (a->sport < b->sport)
(*data)++, (*datalen)--;
}
-#ifdef FWHACK
- if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
- st->len = 0x300; /* big enough to carry to end */
- }
-#endif
-
st->pad = 8 - (st->len % 8);
st->biglen = st->len + st->pad;
pktin.length = st->len - 5;
memcpy(buf + nowlen, pktin.body + 4, msglen);
buf[nowlen + msglen] = '\0';
logevent(buf);
+ bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
+ crReturn(0);
}
crFinish(0);
pktin.data[st->i] = *(*data)++;
(*datalen)--;
}
-#ifdef FWHACK
- if (!memcmp(pktin.data, "Remo", 4)) { /* "Remo"te server has closed ... */
- /* FIXME */
- }
-#endif
+
if (sccipher)
sccipher->decrypt(pktin.data, st->cipherblk);
memcpy(buf + nowlen, pktin.data + 14, msglen);
buf[nowlen + msglen] = '\0';
logevent(buf);
+ bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
+ reason,
+ (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
+ ssh2_disconnect_reasons[reason] : "unknown",
+ buf+nowlen));
+ crReturn(0);
}
crFinish(0);
pktout.body[-1] = pktout.type;
-#ifdef DUMP_PACKETS
- debug(("Packet payload pre-compression:\n"));
- dmemdump(pktout.body - 1, pktout.length + 1);
-#endif
-
if (ssh1_compressing) {
unsigned char *compblk;
int complen;
+#ifdef DUMP_PACKETS
+ debug(("Packet payload pre-compression:\n"));
+ dmemdump(pktout.body - 1, pktout.length + 1);
+#endif
zlib_compress_block(pktout.body - 1, pktout.length + 1,
&compblk, &complen);
ssh1_pktout_size(complen - 1);
memcpy(pktout.body - 1, compblk, complen);
sfree(compblk);
-#ifdef DUMP_PACKETS
- debug(("Packet payload post-compression:\n"));
- dmemdump(pktout.body - 1, pktout.length + 1);
-#endif
}
len = pktout.length + 5; /* type and CRC */
static void s_wrpkt(void)
{
- int len;
+ int len, backlog;
len = s_wrpkt_prepare();
- sk_write(s, pktout.data, len);
+ backlog = sk_write(s, pktout.data, len);
+ if (backlog > SSH_MAX_BACKLOG)
+ ssh_throttle_all(1, backlog);
}
static void s_wrpkt_defer(void)
/*
* Compress packet payload.
*/
-#ifdef DUMP_PACKETS
- debug(("Pre-compression payload:\n"));
- dmemdump(pktout.data + 5, pktout.length - 5);
-#endif
{
unsigned char *newpayload;
int newlen;
+#ifdef DUMP_PACKETS
+ if (cscomp && cscomp != &ssh_comp_none) {
+ debug(("Pre-compression payload:\n"));
+ dmemdump(pktout.data + 5, pktout.length - 5);
+ }
+#endif
if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
&newpayload, &newlen)) {
pktout.length = 5;
*/
static void ssh2_pkt_send(void)
{
- int len = ssh2_pkt_construct();
- sk_write(s, pktout.data, len);
+ int len;
+ int backlog;
+ len = ssh2_pkt_construct();
+ backlog = sk_write(s, pktout.data, len);
+ if (backlog > SSH_MAX_BACKLOG)
+ ssh_throttle_all(1, backlog);
}
/*
*/
static void ssh_pkt_defersend(void)
{
- sk_write(s, deferred_send_data, deferred_len);
+ int backlog;
+ backlog = sk_write(s, deferred_send_data, deferred_len);
deferred_len = deferred_size = 0;
sfree(deferred_send_data);
deferred_send_data = NULL;
+ if (backlog > SSH_MAX_BACKLOG)
+ ssh_throttle_all(1, backlog);
}
#if 0
char *imp; /* pointer to implementation part */
imp = vstring;
imp += strcspn(imp, "-");
- if (*imp)
- imp++;
+ if (*imp) imp++;
imp += strcspn(imp, "-");
- if (*imp)
- imp++;
+ if (*imp) imp++;
ssh_remote_bugs = 0;
if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
!strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
- !strcmp(imp, "1.2.22")) {
+ !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
/*
* These versions don't support SSH1_MSG_IGNORE, so we have
* to use a different defence against password length
logevent("We believe remote version has SSH1 ignore bug");
}
+ if (!strcmp(imp, "Cisco-1.25")) {
+ /*
+ * These versions need a plain password sent; they can't
+ * handle having a null and a random length of data after
+ * the password.
+ */
+ ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
+ logevent("We believe remote version needs a plain SSH1 password");
+ }
+
if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
!strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
!strncmp(imp, "2.1 ", 4)) {
crReturn(1); /* get another character */
}
- vstring = smalloc(16);
vstrsize = 16;
+ vstring = smalloc(vstrsize);
strcpy(vstring, "SSH-");
vslen = 4;
i = 0;
vstring[vslen] = 0;
vlog = smalloc(20 + vslen);
+ vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
sprintf(vlog, "Server version: %s", vstring);
- ssh_detect_bugs(vstring);
- vlog[strcspn(vlog, "\r\n")] = '\0';
logevent(vlog);
+ ssh_detect_bugs(vstring);
sfree(vlog);
/*
while (1) {
while (datalen > 0) {
if (s_rdpkt(&data, &datalen) == 0) {
+ if (ssh_state == SSH_STATE_CLOSED) {
+ return;
+ }
ssh_protocol(NULL, 0, 1);
if (ssh_state == SSH_STATE_CLOSED) {
return;
return 1;
}
+static void ssh_sent(Plug plug, int bufsize)
+{
+ /*
+ * If the send backlog on the SSH socket itself clears, we
+ * should unthrottle the whole world if it was throttled.
+ */
+ if (bufsize < SSH_MAX_BACKLOG)
+ ssh_throttle_all(0, bufsize);
+}
+
/*
* Connect to specified host and port.
* Returns an error message, or NULL on success.
* Also places the canonical host name into `realhost'. It must be
* freed by the caller.
*/
-static char *connect_to_host(char *host, int port, char **realhost)
+static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
{
static struct plug_function_table fn_table = {
ssh_closing,
- ssh_receive
+ ssh_receive,
+ ssh_sent,
+ NULL
}, *fn_table_ptr = &fn_table;
SockAddr addr;
/*
* Try to find host.
*/
+ {
+ char buf[200];
+ sprintf(buf, "Looking up host \"%.170s\"", host);
+ logevent(buf);
+ }
addr = sk_namelookup(host, realhost);
if ((err = sk_addr_error(addr)))
return err;
/*
* Open socket.
*/
- s = sk_new(addr, port, 0, 1, &fn_table_ptr);
+ {
+ char buf[200], addrbuf[100];
+ sk_getaddr(addr, addrbuf, 100);
+ sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
+ logevent(buf);
+ }
+ s = sk_new(addr, port, 0, 1, nodelay, &fn_table_ptr);
if ((err = sk_socket_error(s)))
return err;
}
/*
+ * Throttle or unthrottle the SSH connection.
+ */
+static void ssh1_throttle(int adjust)
+{
+ int old_count = ssh1_throttle_count;
+ ssh1_throttle_count += adjust;
+ assert(ssh1_throttle_count >= 0);
+ if (ssh1_throttle_count && !old_count) {
+ sk_set_frozen(s, 1);
+ } else if (!ssh1_throttle_count && old_count) {
+ sk_set_frozen(s, 0);
+ }
+}
+
+/*
+ * Throttle or unthrottle _all_ local data streams (for when sends
+ * on the SSH connection itself back up).
+ */
+static void ssh_throttle_all(int enable, int bufsize)
+{
+ int i;
+ struct ssh_channel *c;
+
+ if (enable == ssh_throttled_all)
+ return;
+ ssh_throttled_all = enable;
+ ssh_overall_bufsize = bufsize;
+ if (!ssh_channels)
+ return;
+ for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
+ switch (c->type) {
+ case CHAN_MAINSESSION:
+ /*
+ * This is treated separately, outside the switch.
+ */
+ break;
+ case CHAN_X11:
+ x11_override_throttle(c->u.x11.s, enable);
+ break;
+ case CHAN_AGENT:
+ /* Agent channels require no buffer management. */
+ break;
+ case CHAN_SOCKDATA:
+ pfd_override_throttle(c->u.x11.s, enable);
+ break;
+ }
+ }
+}
+
+/*
* Handle the key exchange and user authentication phases.
*/
static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
struct MD5Context md5c;
static unsigned long supported_ciphers_mask, supported_auths_mask;
static int tried_publickey;
+ static int tis_auth_refused, ccard_auth_refused;
static unsigned char session_id[16];
static int cipher_type;
static char username[100];
logevent("Encrypted session key");
- switch (cfg.cipher) {
- case CIPHER_BLOWFISH:
- cipher_type = SSH_CIPHER_BLOWFISH;
- break;
- case CIPHER_DES:
- cipher_type = SSH_CIPHER_DES;
- break;
- case CIPHER_3DES:
- cipher_type = SSH_CIPHER_3DES;
- break;
- case CIPHER_AES:
- c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
- cipher_type = SSH_CIPHER_3DES;
- break;
- }
- if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
- c_write_str
- ("Selected cipher not supported, falling back to 3DES\r\n");
- cipher_type = SSH_CIPHER_3DES;
- if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
- bombout(("Server violates SSH 1 protocol by "
- "not supporting 3DES encryption"));
+ {
+ int cipher_chosen = 0, warn = 0;
+ char *cipher_string = NULL;
+ for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
+ int next_cipher = cfg.ssh_cipherlist[i];
+ if (next_cipher == CIPHER_WARN) {
+ /* If/when we choose a cipher, warn about it */
+ warn = 1;
+ } else if (next_cipher == CIPHER_AES) {
+ /* XXX Probably don't need to mention this. */
+ logevent("AES not supported in SSH1, skipping");
+ } else {
+ switch (next_cipher) {
+ case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
+ cipher_string = "3DES"; break;
+ case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
+ cipher_string = "Blowfish"; break;
+ case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
+ cipher_string = "single-DES"; break;
+ }
+ if (supported_ciphers_mask & (1 << cipher_type))
+ cipher_chosen = 1;
+ }
+ }
+ if (!cipher_chosen) {
+ if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
+ bombout(("Server violates SSH 1 protocol by not "
+ "supporting 3DES encryption"));
+ else
+ /* shouldn't happen */
+ bombout(("No supported ciphers found"));
crReturn(0);
}
+
+ /* Warn about chosen cipher if necessary. */
+ if (warn)
+ askcipher(cipher_string, 0);
}
+
switch (cipher_type) {
case SSH_CIPHER_3DES:
logevent("Using 3DES encryption");
crWaitUntil(ispkt);
tried_publickey = 0;
+ tis_auth_refused = ccard_auth_refused = 0;
while (pktin.type == SSH1_SMSG_FAILURE) {
static char password[100];
static int pos;
static char c;
static int pwpkt_type;
- /*
- * Show password prompt, having first obtained it via a TIS
- * or CryptoCard exchange if we're doing TIS or CryptoCard
- * authentication.
- */
pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
+
if (agent_exists()) {
/*
* Attempt RSA authentication using Pageant.
if (*cfg.keyfile && !tried_publickey)
pwpkt_type = SSH1_CMSG_AUTH_RSA;
- if (pktin.type == SSH1_SMSG_FAILURE &&
- cfg.try_tis_auth &&
- (supported_auths_mask & (1 << SSH1_AUTH_TIS))) {
+ if (cfg.try_tis_auth &&
+ (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
+ !tis_auth_refused) {
pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
logevent("Requested TIS authentication");
send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
logevent("TIS authentication declined");
if (flags & FLAG_INTERACTIVE)
c_write_str("TIS authentication refused.\r\n");
+ tis_auth_refused = 1;
+ continue;
} else {
int challengelen = ((pktin.body[0] << 24) |
(pktin.body[1] << 16) |
if (challengelen > sizeof(prompt) - 1)
challengelen = sizeof(prompt) - 1; /* prevent overrun */
memcpy(prompt, pktin.body + 4, challengelen);
- prompt[challengelen] = '\0';
+ /* Prompt heuristic comes from OpenSSH */
+ strncpy(prompt + challengelen,
+ memchr(prompt, '\n', challengelen) ?
+ "": "\r\nResponse: ",
+ (sizeof prompt) - challengelen);
+ prompt[(sizeof prompt) - 1] = '\0';
}
}
- if (pktin.type == SSH1_SMSG_FAILURE &&
- cfg.try_tis_auth &&
- (supported_auths_mask & (1 << SSH1_AUTH_CCARD))) {
+ if (cfg.try_tis_auth &&
+ (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
+ !ccard_auth_refused) {
pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
logevent("Requested CryptoCard authentication");
send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
logevent("CryptoCard authentication declined");
c_write_str("CryptoCard authentication refused.\r\n");
+ ccard_auth_refused = 1;
+ continue;
} else {
int challengelen = ((pktin.body[0] << 24) |
(pktin.body[1] << 16) |
if (challengelen > sizeof(prompt) - 1)
challengelen = sizeof(prompt) - 1; /* prevent overrun */
memcpy(prompt, pktin.body + 4, challengelen);
- strncpy(prompt + challengelen, "\r\nResponse : ",
+ strncpy(prompt + challengelen,
+ memchr(prompt, '\n', challengelen) ?
+ "" : "\r\nResponse: ",
sizeof(prompt) - challengelen);
prompt[sizeof(prompt) - 1] = '\0';
}
sfree(comment);
}
+ /*
+ * Show password prompt, having first obtained it via a TIS
+ * or CryptoCard exchange if we're doing TIS or CryptoCard
+ * authentication.
+ */
if (ssh_get_line) {
if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
/*
crReturn(1);
}
} else {
- c_write_str(prompt);
+ /* Prompt may have come from server. We've munged it a bit, so
+ * we know it to be zero-terminated at least once. */
+ c_write_untrusted(prompt, strlen(prompt));
pos = 0;
ssh_send_ok = 1;
while (pos >= 0) {
tried_publickey = 1;
i = loadrsakey(cfg.keyfile, &pubkey, password);
if (i == 0) {
- c_write_str("Couldn't load public key from ");
+ c_write_str("Couldn't load private key from ");
c_write_str(cfg.keyfile);
c_write_str(".\r\n");
continue; /* go and try password */
* use of the fact that the password is interpreted
* as a C string: so we can append a NUL, then some
* random data.
+ *
+ * One server (a Cisco one) can deal with neither
+ * SSH1_MSG_IGNORE _nor_ a padded password string.
+ * For this server we are left with no defences
+ * against password length sniffing.
*/
- if (ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) {
- char string[64];
- char *s;
- int len;
-
- len = strlen(password);
- if (len < sizeof(string)) {
- s = string;
- strcpy(string, password);
- len++; /* cover the zero byte */
- while (len < sizeof(string)) {
- string[len++] = (char) random_byte();
- }
- } else {
- s = password;
- }
- send_packet(pwpkt_type, PKT_INT, len,
- PKT_DATA, s, len, PKT_END);
- } else {
+ if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
+ /*
+ * The server can deal with SSH1_MSG_IGNORE, so
+ * we can use the primary defence.
+ */
int bottom, top, pwlen, i;
char *randomstr;
PKT_STR, randomstr, PKT_END);
}
}
+ logevent("Sending password with camouflage packets");
ssh_pkt_defersend();
+ }
+ else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
+ /*
+ * The server can't deal with SSH1_MSG_IGNORE
+ * but can deal with padded passwords, so we
+ * can use the secondary defence.
+ */
+ char string[64];
+ char *s;
+ int len;
+
+ len = strlen(password);
+ if (len < sizeof(string)) {
+ s = string;
+ strcpy(string, password);
+ len++; /* cover the zero byte */
+ while (len < sizeof(string)) {
+ string[len++] = (char) random_byte();
+ }
+ } else {
+ s = password;
+ }
+ logevent("Sending length-padded password");
+ send_packet(pwpkt_type, PKT_INT, len,
+ PKT_DATA, s, len, PKT_END);
+ } else {
+ /*
+ * The server has _both_
+ * BUG_CHOKES_ON_SSH1_IGNORE and
+ * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
+ * therefore nothing we can do.
+ */
+ int len;
+ len = strlen(password);
+ logevent("Sending unpadded password");
+ send_packet(pwpkt_type, PKT_INT, len,
+ PKT_DATA, password, len, PKT_END);
}
} else {
send_packet(pwpkt_type, PKT_STR, password, PKT_END);
void sshfwd_close(struct ssh_channel *c)
{
if (c && !c->closes) {
- if (ssh_version == 1) {
- send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
- PKT_END);
- } else {
- ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
- ssh2_pkt_adduint32(c->remoteid);
- ssh2_pkt_send();
+ /*
+ * 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 (c->remoteid != -1) {
+ if (ssh_version == 1) {
+ send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
+ PKT_END);
+ } else {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_send();
+ }
}
c->closes = 1;
if (c->type == CHAN_X11) {
c->u.x11.s = NULL;
logevent("Forwarded X11 connection terminated");
- } else if (c->type == CHAN_SOCKDATA) {
+ } else if (c->type == CHAN_SOCKDATA ||
+ c->type == CHAN_SOCKDATA_DORMANT) {
c->u.pfd.s = NULL;
logevent("Forwarded port closed");
}
}
}
-void sshfwd_write(struct ssh_channel *c, char *buf, int len)
+int sshfwd_write(struct ssh_channel *c, char *buf, int len)
{
if (ssh_version == 1) {
send_packet(SSH1_MSG_CHANNEL_DATA,
PKT_INT, c->remoteid,
PKT_INT, len, PKT_DATA, buf, len, 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);
- ssh2_try_send(c);
+ return ssh2_try_send(c);
+ }
+}
+
+void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
+{
+ if (ssh_version == 1) {
+ if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
+ c->v.v1.throttling = 0;
+ ssh1_throttle(-1);
+ }
+ } else {
+ ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
}
}
zlib_decompress_init();
}
- if (*cfg.remote_cmd_ptr)
- send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd_ptr,
- PKT_END);
- else
- send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
- logevent("Started session");
+ /*
+ * 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 = cfg.remote_cmd_ptr;
+
+ if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
+ cmd = cfg.remote_cmd_ptr2;
+ ssh_fallback_cmd = TRUE;
+ }
+ if (*cmd)
+ send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
+ else
+ send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
+ logevent("Started session");
+ }
ssh_state = SSH_STATE_SESSION;
if (size_needed)
if (eof_needed)
ssh_special(TS_EOF);
- ldisc_send(NULL, 0); /* cause ldisc to notice changes */
+ ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
ssh_send_ok = 1;
ssh_channels = newtree234(ssh_channelcmp);
while (1) {
if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
pktin.type == SSH1_SMSG_STDERR_DATA) {
long len = GET_32BIT(pktin.body);
- from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
- pktin.body + 4, len);
+ int bufsize =
+ from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
+ pktin.body + 4, len);
+ if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
+ ssh1_stdout_throttling = 1;
+ ssh1_throttle(+1);
+ }
} else if (pktin.type == SSH1_MSG_DISCONNECT) {
ssh_state = SSH_STATE_CLOSED;
logevent("Received disconnect request");
c->remoteid = GET_32BIT(pktin.body);
c->localid = alloc_channel_id();
c->closes = 0;
+ c->v.v1.throttling = 0;
c->type = CHAN_X11; /* identify channel type */
add234(ssh_channels, c);
send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
c->remoteid = GET_32BIT(pktin.body);
c->localid = alloc_channel_id();
c->closes = 0;
+ c->v.v1.throttling = 0;
c->type = CHAN_AGENT; /* identify channel type */
c->u.a.lensofar = 0;
add234(ssh_channels, c);
c->remoteid = GET_32BIT(pktin.body);
c->localid = alloc_channel_id();
c->closes = 0;
+ c->v.v1.throttling = 0;
c->type = CHAN_SOCKDATA; /* identify channel type */
add234(ssh_channels, c);
send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
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(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
+ PKT_END);
+ }
+
+ } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
+ unsigned int remoteid = GET_32BIT(pktin.body);
+ unsigned int localid = GET_32BIT(pktin.body+4);
+ 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);
+ }
+
} else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
/* Remote side closes a channel. */
struct ssh_channel *c;
c = find234(ssh_channels, &i, ssh_channelfind);
if (c) {
+ int bufsize;
switch (c->type) {
case CHAN_X11:
- x11_send(c->u.x11.s, p, len);
+ bufsize = x11_send(c->u.x11.s, p, len);
break;
case CHAN_SOCKDATA:
- pfd_send(c->u.pfd.s, p, len);
+ bufsize = pfd_send(c->u.pfd.s, p, len);
break;
case CHAN_AGENT:
/* Data for an agent message. Buffer it. */
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(+1);
+ }
}
} else if (pktin.type == SSH1_SMSG_SUCCESS) {
/* may be from EXEC_SHELL on some servers */
* if no pty is available or in other odd cases. Ignore */
} else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
send_packet(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_state = SSH_STATE_CLOSED;
+ crReturnV;
} else {
bombout(("Strange packet received: type %d", pktin.type));
crReturnV;
*/
static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
{
- static int i, j, len, nbits, pbits;
+ static int i, j, len, nbits, pbits, warn;
static char *str;
static Bignum p, g, e, f, K;
static int kex_init_value, kex_reply_value;
static void *hkey; /* actual host key */
static unsigned char exchange_hash[20];
static unsigned char keyspace[40];
- static const struct ssh2_ciphers *preferred_cipher;
+ static int n_preferred_ciphers;
+ static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
static const struct ssh_compress *preferred_comp;
static int first_kex;
first_kex = 1;
/*
- * Set up the preferred cipher and compression.
+ * Set up the preferred ciphers. (NULL => warn below here)
*/
- if (cfg.cipher == CIPHER_BLOWFISH) {
- preferred_cipher = &ssh2_blowfish;
- } else if (cfg.cipher == CIPHER_DES) {
- logevent("Single DES not supported in SSH2; using 3DES");
- preferred_cipher = &ssh2_3des;
- } else if (cfg.cipher == CIPHER_3DES) {
- preferred_cipher = &ssh2_3des;
- } else if (cfg.cipher == CIPHER_AES) {
- preferred_cipher = &ssh2_aes;
- } else {
- /* Shouldn't happen, but we do want to initialise to _something_. */
- preferred_cipher = &ssh2_3des;
+ n_preferred_ciphers = 0;
+ for (i = 0; i < CIPHER_MAX; i++) {
+ switch (cfg.ssh_cipherlist[i]) {
+ case CIPHER_BLOWFISH:
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
+ n_preferred_ciphers++;
+ break;
+ case CIPHER_DES:
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
+ n_preferred_ciphers++;
+ break;
+ case CIPHER_3DES:
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
+ n_preferred_ciphers++;
+ break;
+ case CIPHER_AES:
+ preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
+ n_preferred_ciphers++;
+ break;
+ case CIPHER_WARN:
+ /* Flag for later. Don't bother if it's the last in
+ * the list. */
+ if (i < CIPHER_MAX - 1) {
+ preferred_ciphers[n_preferred_ciphers] = NULL;
+ n_preferred_ciphers++;
+ }
+ break;
+ }
}
+
+ /*
+ * Set up preferred compression.
+ */
if (cfg.compression)
preferred_comp = &ssh_zlib;
else
}
/* List client->server encryption algorithms. */
ssh2_pkt_addstring_start();
- for (i = 0; i < lenof(ciphers) + 1; i++) {
- const struct ssh2_ciphers *c =
- i == 0 ? preferred_cipher : ciphers[i - 1];
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) continue; /* warning flag */
for (j = 0; j < c->nciphers; j++) {
ssh2_pkt_addstring_str(c->list[j]->name);
- if (i < lenof(ciphers) || j < c->nciphers - 1)
+ if (i < n_preferred_ciphers || j < c->nciphers - 1)
ssh2_pkt_addstring_str(",");
}
}
/* List server->client encryption algorithms. */
ssh2_pkt_addstring_start();
- for (i = 0; i < lenof(ciphers) + 1; i++) {
- const struct ssh2_ciphers *c =
- i == 0 ? preferred_cipher : ciphers[i - 1];
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) continue; /* warning flag */
for (j = 0; j < c->nciphers; j++) {
ssh2_pkt_addstring_str(c->list[j]->name);
- if (i < lenof(ciphers) || j < c->nciphers - 1)
+ if (i < n_preferred_ciphers || j < c->nciphers - 1)
ssh2_pkt_addstring_str(",");
}
}
}
}
ssh2_pkt_getstring(&str, &len); /* client->server cipher */
- for (i = 0; i < lenof(ciphers) + 1; i++) {
- const struct ssh2_ciphers *c =
- i == 0 ? preferred_cipher : ciphers[i - 1];
- for (j = 0; j < c->nciphers; j++) {
- if (in_commasep_string(c->list[j]->name, str, len)) {
- cscipher_tobe = c->list[j];
- break;
+ warn = 0;
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) {
+ warn = 1;
+ } else {
+ for (j = 0; j < c->nciphers; j++) {
+ if (in_commasep_string(c->list[j]->name, str, len)) {
+ cscipher_tobe = c->list[j];
+ break;
+ }
}
}
- if (cscipher_tobe)
+ if (cscipher_tobe) {
+ if (warn)
+ askcipher(cscipher_tobe->name, 1);
break;
+ }
+ }
+ if (!cscipher_tobe) {
+ bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
+ crReturn(0);
}
+
ssh2_pkt_getstring(&str, &len); /* server->client cipher */
- for (i = 0; i < lenof(ciphers) + 1; i++) {
- const struct ssh2_ciphers *c =
- i == 0 ? preferred_cipher : ciphers[i - 1];
- for (j = 0; j < c->nciphers; j++) {
- if (in_commasep_string(c->list[j]->name, str, len)) {
- sccipher_tobe = c->list[j];
- break;
+ warn = 0;
+ for (i = 0; i < n_preferred_ciphers; i++) {
+ const struct ssh2_ciphers *c = preferred_ciphers[i];
+ if (!c) {
+ warn = 1;
+ } else {
+ for (j = 0; j < c->nciphers; j++) {
+ if (in_commasep_string(c->list[j]->name, str, len)) {
+ sccipher_tobe = c->list[j];
+ break;
+ }
}
}
- if (sccipher_tobe)
+ if (sccipher_tobe) {
+ if (warn)
+ askcipher(sccipher_tobe->name, 2);
break;
+ }
+ }
+ if (!sccipher_tobe) {
+ bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
+ crReturn(0);
}
+
ssh2_pkt_getstring(&str, &len); /* client->server mac */
for (i = 0; i < nmacs; i++) {
if (in_commasep_string(maclist[i]->name, str, len)) {
}
/*
- * Expect SSH2_MSG_NEWKEYS from server.
- */
- crWaitUntil(ispkt);
- if (pktin.type != SSH2_MSG_NEWKEYS) {
- bombout(("expected new-keys packet from server"));
- crReturn(0);
- }
-
- /*
* Authenticate remote host: verify host key. (We've already
* checked the signature of the exchange hash.)
*/
ssh2_pkt_send();
/*
+ * Expect SSH2_MSG_NEWKEYS from server.
+ */
+ crWaitUntil(ispkt);
+ if (pktin.type != SSH2_MSG_NEWKEYS) {
+ bombout(("expected new-keys packet from server"));
+ crReturn(0);
+ }
+
+ /*
* Create and initialise session keys.
*/
cscipher = cscipher_tobe;
static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
int len)
{
- if (c->v2.outbufsize < c->v2.outbuflen + len) {
- c->v2.outbufsize = c->v2.outbuflen + len + 1024;
- c->v2.outbuffer = srealloc(c->v2.outbuffer, c->v2.outbufsize);
- }
- memcpy(c->v2.outbuffer + c->v2.outbuflen, buf, len);
- c->v2.outbuflen += len;
+ bufchain_add(&c->v.v2.outbuffer, buf, len);
}
/*
* Attempt to send data on an SSH2 channel.
*/
-static void ssh2_try_send(struct ssh_channel *c)
+static int ssh2_try_send(struct ssh_channel *c)
{
- while (c->v2.remwindow > 0 && c->v2.outbuflen > 0) {
- unsigned len = c->v2.remwindow;
- if (len > c->v2.outbuflen)
- len = c->v2.outbuflen;
- if (len > c->v2.remmaxpkt)
- len = c->v2.remmaxpkt;
+ while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
+ int len;
+ void *data;
+ bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
+ if ((unsigned)len > c->v.v2.remwindow)
+ len = c->v.v2.remwindow;
+ if ((unsigned)len > c->v.v2.remmaxpkt)
+ len = c->v.v2.remmaxpkt;
ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
ssh2_pkt_adduint32(c->remoteid);
ssh2_pkt_addstring_start();
- ssh2_pkt_addstring_data(c->v2.outbuffer, len);
+ ssh2_pkt_addstring_data(data, len);
+ ssh2_pkt_send();
+ bufchain_consume(&c->v.v2.outbuffer, len);
+ c->v.v2.remwindow -= len;
+ }
+
+ /*
+ * After having sent as much data as we can, return the amount
+ * still buffered.
+ */
+ return bufchain_size(&c->v.v2.outbuffer);
+}
+
+/*
+ * Potentially enlarge the window on an SSH2 channel.
+ */
+static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
+{
+ if (newwin > c->v.v2.locwindow) {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
ssh2_pkt_send();
- c->v2.outbuflen -= len;
- memmove(c->v2.outbuffer, c->v2.outbuffer + len, c->v2.outbuflen);
- c->v2.remwindow -= len;
+ c->v.v2.locwindow = newwin;
}
}
* This is a further prompt in keyboard-interactive
* authentication. Do nothing.
*/
- } else if (!pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
+ } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
bombout(("Strange packet received during authentication: type %d",
pktin.type));
crReturnV;
in_commasep_string("publickey", methods, methlen);
can_passwd =
in_commasep_string("password", methods, methlen);
- can_passwd =
- in_commasep_string("password", methods, methlen);
- can_keyb_inter =
+ can_keyb_inter = cfg.try_ki_auth &&
in_commasep_string("keyboard-interactive", methods, methlen);
}
method = 0;
- if (!method && can_keyb_inter && !tried_keyb_inter) {
- method = AUTH_KEYBOARD_INTERACTIVE;
- type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
- tried_keyb_inter = TRUE;
-
- ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
- ssh2_pkt_addstring(username);
- ssh2_pkt_addstring("ssh-connection"); /* service requested */
- ssh2_pkt_addstring("keyboard-interactive"); /* method */
- ssh2_pkt_addstring(""); /* lang */
- ssh2_pkt_addstring("");
- ssh2_pkt_send();
-
- crWaitUntilV(ispkt);
- if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
- if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
- gotit = TRUE;
- logevent("Keyboard-interactive authentication refused");
- type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
- continue;
- }
-
- kbd_inter_running = TRUE;
- }
-
- if (kbd_inter_running) {
- method = AUTH_KEYBOARD_INTERACTIVE;
- type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
- tried_keyb_inter = TRUE;
-
- /* We've got packet with that "interactive" info
- dump banners, and set its prompt as ours */
- {
- char *name, *inst, *lang, *prompt;
- int name_len, inst_len, lang_len, prompt_len;
- ssh2_pkt_getstring(&name, &name_len);
- ssh2_pkt_getstring(&inst, &inst_len);
- ssh2_pkt_getstring(&lang, &lang_len);
- if (name_len > 0)
- c_write_untrusted(name, name_len);
- if (inst_len > 0)
- c_write_untrusted(inst, inst_len);
- num_prompts = ssh2_pkt_getuint32();
-
- ssh2_pkt_getstring(&prompt, &prompt_len);
- strncpy(pwprompt, prompt, sizeof(pwprompt));
- need_pw = TRUE;
-
- echo = ssh2_pkt_getbool();
- }
- }
-
if (!method && can_pubkey && agent_exists() && !tried_agent) {
/*
* Attempt public-key authentication using Pageant.
}
}
+ if (!method && can_keyb_inter && !tried_keyb_inter) {
+ method = AUTH_KEYBOARD_INTERACTIVE;
+ type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
+ tried_keyb_inter = TRUE;
+
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+ ssh2_pkt_addstring(username);
+ ssh2_pkt_addstring("ssh-connection"); /* service requested */
+ ssh2_pkt_addstring("keyboard-interactive"); /* method */
+ ssh2_pkt_addstring(""); /* lang */
+ ssh2_pkt_addstring("");
+ ssh2_pkt_send();
+
+ crWaitUntilV(ispkt);
+ if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
+ if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
+ gotit = TRUE;
+ logevent("Keyboard-interactive authentication refused");
+ type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
+ continue;
+ }
+
+ kbd_inter_running = TRUE;
+ }
+
+ if (kbd_inter_running) {
+ method = AUTH_KEYBOARD_INTERACTIVE;
+ type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
+ tried_keyb_inter = TRUE;
+
+ /* We've got packet with that "interactive" info
+ dump banners, and set its prompt as ours */
+ {
+ char *name, *inst, *lang, *prompt;
+ int name_len, inst_len, lang_len, prompt_len;
+ ssh2_pkt_getstring(&name, &name_len);
+ ssh2_pkt_getstring(&inst, &inst_len);
+ ssh2_pkt_getstring(&lang, &lang_len);
+ if (name_len > 0)
+ c_write_untrusted(name, name_len);
+ if (inst_len > 0)
+ c_write_untrusted(inst, inst_len);
+ num_prompts = ssh2_pkt_getuint32();
+
+ ssh2_pkt_getstring(&prompt, &prompt_len);
+ strncpy(pwprompt, prompt, sizeof(pwprompt));
+ pwprompt[prompt_len < sizeof(pwprompt) ?
+ prompt_len : sizeof(pwprompt)-1] = '\0';
+ need_pw = TRUE;
+
+ echo = ssh2_pkt_getbool();
+ }
+ }
+
if (!method && can_passwd) {
method = AUTH_PASSWORD;
sprintf(pwprompt, "%.90s@%.90s's password: ", username,
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
ssh2_pkt_addstring("session");
ssh2_pkt_adduint32(mainchan->localid);
- ssh2_pkt_adduint32(0x8000UL); /* our window size */
+ mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
+ ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
ssh2_pkt_send();
crWaitUntilV(ispkt);
mainchan->remoteid = ssh2_pkt_getuint32();
mainchan->type = CHAN_MAINSESSION;
mainchan->closes = 0;
- mainchan->v2.remwindow = ssh2_pkt_getuint32();
- mainchan->v2.remmaxpkt = ssh2_pkt_getuint32();
- mainchan->v2.outbuffer = NULL;
- mainchan->v2.outbuflen = mainchan->v2.outbufsize = 0;
+ mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
+ mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
+ bufchain_init(&mainchan->v.v2.outbuffer);
add234(ssh_channels, mainchan);
logevent("Opened channel for session");
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue; /* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
}
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
- bombout(("Server got confused by X11 forwarding request"));
+ bombout(("Unexpected response to X11 forwarding request:"
+ " packet type %d", pktin.type));
crReturnV;
}
logevent("X11 forwarding refused");
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue;/* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
}
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
- bombout(("Server got confused by port forwarding request"));
+ bombout(("Unexpected response to port "
+ "forwarding request: packet type %d",
+ pktin.type));
crReturnV;
}
logevent("Server refused this port forwarding");
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue; /* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
}
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
- bombout(
- ("Server got confused by agent forwarding request"));
+ bombout(("Unexpected response to agent forwarding request:"
+ " packet type %d", pktin.type));
crReturnV;
}
logevent("Agent forwarding refused");
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue; /* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
}
} while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
- bombout(("Server got confused by pty request"));
+ bombout(("Unexpected response to pty request:"
+ " packet type %d", pktin.type));
crReturnV;
}
c_write_str("Server refused to allocate pty\r\n");
}
/*
- * Start a shell or a remote command.
+ * Start a shell or a remote command. We may have to attempt
+ * this twice if the config data has provided a second choice
+ * of command.
*/
- ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
- ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
- if (cfg.ssh_subsys) {
- ssh2_pkt_addstring("subsystem");
- ssh2_pkt_addbool(1); /* want reply */
- ssh2_pkt_addstring(cfg.remote_cmd_ptr);
- } else if (*cfg.remote_cmd_ptr) {
- ssh2_pkt_addstring("exec");
- ssh2_pkt_addbool(1); /* want reply */
- ssh2_pkt_addstring(cfg.remote_cmd_ptr);
- } else {
- ssh2_pkt_addstring("shell");
- ssh2_pkt_addbool(1); /* want reply */
- }
- ssh2_pkt_send();
- do {
- crWaitUntilV(ispkt);
- if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
- unsigned i = ssh2_pkt_getuint32();
- struct ssh_channel *c;
- c = find234(ssh_channels, &i, ssh_channelfind);
- if (!c)
- continue; /* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ while (1) {
+ int subsys;
+ char *cmd;
+
+ if (ssh_fallback_cmd) {
+ subsys = cfg.ssh_subsys2;
+ cmd = cfg.remote_cmd_ptr2;
+ } else {
+ subsys = cfg.ssh_subsys;
+ cmd = cfg.remote_cmd_ptr;
}
- } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
- if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
- if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
- bombout(("Server got confused by shell/command request"));
+
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
+ ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
+ if (subsys) {
+ ssh2_pkt_addstring("subsystem");
+ ssh2_pkt_addbool(1); /* want reply */
+ ssh2_pkt_addstring(cmd);
+ } else if (*cmd) {
+ ssh2_pkt_addstring("exec");
+ ssh2_pkt_addbool(1); /* want reply */
+ ssh2_pkt_addstring(cmd);
+ } else {
+ ssh2_pkt_addstring("shell");
+ ssh2_pkt_addbool(1); /* want reply */
+ }
+ ssh2_pkt_send();
+ do {
+ crWaitUntilV(ispkt);
+ if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
+ }
+ } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+ if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
+ if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
+ bombout(("Unexpected response to shell/command request:"
+ " packet type %d", pktin.type));
+ crReturnV;
+ }
+ /*
+ * We failed to start the command. If this is the
+ * fallback command, we really are finished; if it's
+ * not, and if the fallback command exists, try falling
+ * back to it before complaining.
+ */
+ if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
+ logevent("Primary command failed; attempting fallback");
+ ssh_fallback_cmd = TRUE;
+ continue;
+ }
+ bombout(("Server refused to start a shell/command"));
crReturnV;
+ } else {
+ logevent("Started a shell/command");
}
- bombout(("Server refused to start a shell/command"));
- crReturnV;
- } else {
- logevent("Started a shell/command");
+ break;
}
ssh_state = SSH_STATE_SESSION;
/*
* Transfer data!
*/
- ldisc_send(NULL, 0); /* cause ldisc to notice changes */
+ ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
ssh_send_ok = 1;
while (1) {
static int try_send;
continue; /* extended but not stderr */
ssh2_pkt_getstring(&data, &length);
if (data) {
+ int bufsize;
+ c->v.v2.locwindow -= length;
switch (c->type) {
case CHAN_MAINSESSION:
- from_backend(pktin.type ==
- SSH2_MSG_CHANNEL_EXTENDED_DATA, data,
- length);
+ bufsize =
+ from_backend(pktin.type ==
+ SSH2_MSG_CHANNEL_EXTENDED_DATA,
+ data, length);
break;
case CHAN_X11:
- x11_send(c->u.x11.s, data, length);
+ bufsize = x11_send(c->u.x11.s, data, length);
break;
case CHAN_SOCKDATA:
- pfd_send(c->u.pfd.s, data, length);
+ bufsize = pfd_send(c->u.pfd.s, data, length);
break;
case CHAN_AGENT:
while (length > 0) {
c->u.a.lensofar = 0;
}
}
+ bufsize = 0;
break;
}
/*
- * Enlarge the window again at the remote
- * side, just in case it ever runs down and
- * they fail to send us any more data.
+ * If we are not buffering too much data,
+ * enlarge the window again at the remote side.
*/
- ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
- ssh2_pkt_adduint32(c->remoteid);
- ssh2_pkt_adduint32(length);
- ssh2_pkt_send();
+ if (bufsize < OUR_V2_WINSIZE)
+ ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
}
} else if (pktin.type == SSH2_MSG_DISCONNECT) {
ssh_state = SSH_STATE_CLOSED;
logevent("Received disconnect message");
crReturnV;
- } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
- continue; /* exit status et al; ignore (FIXME?) */
} else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
unsigned i = ssh2_pkt_getuint32();
struct ssh_channel *c;
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue; /* nonexistent channel */
- if (c->closes == 0) {
- ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
- ssh2_pkt_adduint32(c->remoteid);
- ssh2_pkt_send();
- }
/* Do pre-close processing on the channel. */
switch (c->type) {
case CHAN_MAINSESSION:
break; /* nothing to see here, move along */
case CHAN_X11:
+ if (c->u.x11.s != NULL)
+ x11_close(c->u.x11.s);
+ sshfwd_close(c);
break;
case CHAN_AGENT:
+ sshfwd_close(c);
break;
case CHAN_SOCKDATA:
+ if (c->u.pfd.s != NULL)
+ pfd_close(c->u.pfd.s);
+ sshfwd_close(c);
break;
}
+ if (c->closes == 0) {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_send();
+ }
del234(ssh_channels, c);
- sfree(c->v2.outbuffer);
+ bufchain_clear(&c->v.v2.outbuffer);
sfree(c);
/*
c = find234(ssh_channels, &i, ssh_channelfind);
if (!c)
continue; /* nonexistent channel */
- c->v2.remwindow += ssh2_pkt_getuint32();
+ c->v.v2.remwindow += ssh2_pkt_getuint32();
try_send = TRUE;
} else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
unsigned i = ssh2_pkt_getuint32();
continue; /* dunno why they're confirming this */
c->remoteid = ssh2_pkt_getuint32();
c->type = CHAN_SOCKDATA;
- c->closes = 0;
- c->v2.remwindow = ssh2_pkt_getuint32();
- c->v2.remmaxpkt = ssh2_pkt_getuint32();
- c->v2.outbuffer = NULL;
- c->v2.outbuflen = c->v2.outbufsize = 0;
- pfd_confirm(c->u.pfd.s);
+ c->v.v2.remwindow = ssh2_pkt_getuint32();
+ c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
+ bufchain_init(&c->v.v2.outbuffer);
+ if (c->u.pfd.s)
+ pfd_confirm(c->u.pfd.s);
+ if (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.
+ */
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_send();
+ }
+ } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
+ unsigned i = ssh2_pkt_getuint32();
+ struct ssh_channel *c;
+ c = find234(ssh_channels, &i, ssh_channelfind);
+ if (!c)
+ continue; /* nonexistent channel */
+ if (c->type != CHAN_SOCKDATA_DORMANT)
+ continue; /* dunno why they're failing this */
+
+ logevent("Forwarded connection refused by server");
+
+ pfd_close(c->u.pfd.s);
+
+ del234(ssh_channels, c);
+ sfree(c);
+ } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
+ unsigned localid;
+ char *type;
+ int typelen, want_reply;
+ struct ssh_channel *c;
+
+ localid = ssh2_pkt_getuint32();
+ ssh2_pkt_getstring(&type, &typelen);
+ want_reply = ssh2_pkt_getbool();
+
+ /*
+ * First, check that the channel exists. Otherwise,
+ * we can instantly disconnect with a rude message.
+ */
+ c = find234(ssh_channels, &localid, ssh_channelfind);
+ if (!c) {
+ char buf[80];
+ sprintf(buf, "Received channel request for nonexistent"
+ " channel %d", localid);
+ logevent(buf);
+ ssh2_pkt_init(SSH2_MSG_DISCONNECT);
+ ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
+ ssh2_pkt_addstring(buf);
+ ssh2_pkt_addstring("en"); /* language tag */
+ ssh2_pkt_send();
+ connection_fatal(buf);
+ ssh_state = SSH_STATE_CLOSED;
+ crReturnV;
+ }
+
+ /*
+ * We don't recognise any form of channel request,
+ * so we now either ignore the request or respond
+ * with CHANNEL_FAILURE, depending on want_reply.
+ */
+ if (want_reply) {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
+ ssh2_pkt_adduint32(c->remoteid);
+ ssh2_pkt_send();
+ }
} else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
char *type;
int typelen;
} else {
c->localid = alloc_channel_id();
c->closes = 0;
- c->v2.remwindow = winsize;
- c->v2.remmaxpkt = pktsize;
- c->v2.outbuffer = NULL;
- c->v2.outbuflen = c->v2.outbufsize = 0;
+ c->v.v2.locwindow = OUR_V2_WINSIZE;
+ c->v.v2.remwindow = winsize;
+ c->v.v2.remmaxpkt = pktsize;
+ bufchain_init(&c->v.v2.outbuffer);
add234(ssh_channels, c);
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
ssh2_pkt_adduint32(c->remoteid);
ssh2_pkt_adduint32(c->localid);
- ssh2_pkt_adduint32(0x8000UL); /* our window size */
+ ssh2_pkt_adduint32(c->v.v2.locwindow);
ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
ssh2_pkt_send();
}
/*
* Try to send data on all channels if we can.
*/
- for (i = 0; NULL != (c = index234(ssh_channels, i)); i++)
- ssh2_try_send(c);
+ for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
+ int bufsize = ssh2_try_send(c);
+ if (bufsize == 0) {
+ switch (c->type) {
+ case CHAN_MAINSESSION:
+ /* stdin need not receive an unthrottle
+ * notification since it will be polled */
+ break;
+ case CHAN_X11:
+ x11_unthrottle(c->u.x11.s);
+ break;
+ case CHAN_AGENT:
+ /* agent sockets are request/response and need no
+ * buffer management */
+ break;
+ case CHAN_SOCKDATA:
+ pfd_unthrottle(c->u.pfd.s);
+ break;
+ }
+ }
+ }
}
}
*
* Returns an error message, or NULL on success.
*/
-static char *ssh_init(char *host, int port, char **realhost)
+static char *ssh_init(char *host, int port, char **realhost, int nodelay)
{
char *p;
ssh_send_ok = 0;
ssh_editing = 0;
ssh_echoing = 0;
+ ssh1_throttle_count = 0;
+ ssh_overall_bufsize = 0;
+ ssh_fallback_cmd = 0;
- p = connect_to_host(host, port, realhost);
+ p = connect_to_host(host, port, realhost, nodelay);
if (p != NULL)
return p;
/*
* Called to send data down the Telnet connection.
*/
-static void ssh_send(char *buf, int len)
+static int ssh_send(char *buf, int len)
{
if (s == NULL || ssh_protocol == NULL)
- return;
+ return 0;
ssh_protocol(buf, len, 0);
+
+ return ssh_sendbuffer();
+}
+
+/*
+ * Called to query the current amount of buffered stdin data.
+ */
+static int ssh_sendbuffer(void)
+{
+ int override_value;
+
+ if (s == NULL || ssh_protocol == NULL)
+ return 0;
+
+ /*
+ * If the SSH socket itself has backed up, add the total backup
+ * size on that to any individual buffer on the stdin channel.
+ */
+ override_value = 0;
+ if (ssh_throttled_all)
+ override_value = ssh_overall_bufsize;
+
+ if (ssh_version == 1) {
+ return override_value;
+ } else if (ssh_version == 2) {
+ if (!mainchan || mainchan->closes > 0)
+ return override_value;
+ else
+ return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
+ }
+
+ return 0;
}
/*
return c;
}
+/*
+ * This is called when stdout/stderr (the entity to which
+ * from_backend sends data) manages to clear some backlog.
+ */
+void ssh_unthrottle(int bufsize)
+{
+ if (ssh_version == 1) {
+ if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
+ ssh1_stdout_throttling = 0;
+ ssh1_throttle(-1);
+ }
+ } else {
+ if (mainchan && mainchan->closes == 0)
+ ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
+ }
+}
+
void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
{
struct ssh_channel *c = (struct ssh_channel *)channel;
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
ssh2_pkt_addstring("direct-tcpip");
ssh2_pkt_adduint32(c->localid);
- ssh2_pkt_adduint32(0x8000UL); /* our window size */
+ c->v.v2.locwindow = OUR_V2_WINSIZE;
+ ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
ssh2_pkt_addstring(hostname);
ssh2_pkt_adduint32(port);
Backend ssh_backend = {
ssh_init,
ssh_send,
+ ssh_sendbuffer,
ssh_size,
ssh_special,
ssh_socket,
ssh_sendok,
ssh_ldisc,
+ ssh_unthrottle,
22
};
projects / u / mdw / putty / blobdiff