#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
+#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
+#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
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 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
CHAN_MAINSESSION,
CHAN_X11,
CHAN_AGENT,
+ CHAN_SOCKDATA,
+ CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
};
/*
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;
struct ssh_x11_channel {
Socket s;
} x11;
+ struct ssh_pfd_channel {
+ Socket s;
+ } pfd;
} u;
};
+/*
+ * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
+ * 2 use this structure in different ways, reflecting SSH 2's
+ * altogether saner approach to port forwarding.
+ *
+ * In SSH 1, you arrange a remote forwarding by sending the server
+ * the remote port number, and the local destination host:port.
+ * When a connection comes in, the server sends you back that
+ * host:port pair, and you connect to it. This is a ready-made
+ * security hole if you're not on the ball: a malicious server
+ * could send you back _any_ host:port pair, so if you trustingly
+ * connect to the address it gives you then you've just opened the
+ * entire inside of your corporate network just by connecting
+ * through it to a dodgy SSH server. Hence, we must store a list of
+ * host:port pairs we _are_ trying to forward to, and reject a
+ * connection request from the server if it's not in the list.
+ *
+ * In SSH 2, each side of the connection minds its own business and
+ * doesn't send unnecessary information to the other. You arrange a
+ * remote forwarding by sending the server just the remote port
+ * number. When a connection comes in, the server tells you which
+ * of its ports was connected to; and _you_ have to remember what
+ * local host:port pair went with that port number.
+ *
+ * Hence: in SSH 1 this structure stores host:port pairs we intend
+ * to allow connections to, and is indexed by those host:port
+ * pairs. In SSH 2 it stores a mapping from source port to
+ * destination host:port pair, and is indexed by source port.
+ */
+struct ssh_rportfwd {
+ unsigned sport, dport;
+ char dhost[256];
+};
+
struct Packet {
long length;
int type;
static tree234 *ssh_channels; /* indexed by local id */
static struct ssh_channel *mainchan; /* primary session channel */
+static tree234 *ssh_rportfwds;
+
static enum {
SSH_STATE_PREPACKET,
SSH_STATE_BEFORE_SIZE,
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;
return 0;
}
+static int ssh_rportcmp_ssh1(void *av, void *bv)
+{
+ struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
+ struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
+ int i;
+ if ( (i = strcmp(a->dhost, b->dhost)) != 0)
+ return i < 0 ? -1 : +1;
+ if (a->dport > b->dport)
+ return +1;
+ if (a->dport < b->dport)
+ return -1;
+ return 0;
+}
+
+static int ssh_rportcmp_ssh2(void *av, void *bv)
+{
+ struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
+ struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
+
+ if (a->sport > b->sport)
+ return +1;
+ if (a->sport < b->sport)
+ return -1;
+ return 0;
+}
+
static int alloc_channel_id(void)
{
const unsigned CHANNEL_NUMBER_OFFSET = 256;
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)
*/
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
static int do_ssh_init(unsigned char c)
{
- static char vslen;
+ static int vslen;
static char version[10];
static char *vstring;
static int vstrsize;
int calling_back)
{
ssh_state = SSH_STATE_CLOSED;
- sk_close(s);
- s = NULL;
+ if (s) {
+ sk_close(s);
+ s = NULL;
+ }
if (error_msg) {
/* A socket error has occurred. */
connection_fatal(error_msg);
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.
{
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.
*/
+ {
+ 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, &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)
{
- int i, j, len;
- unsigned char *rsabuf, *keystr1, *keystr2;
+ int i, j;
+ static int len;
+ static unsigned char *rsabuf, *keystr1, *keystr2;
unsigned char cookie[8];
struct RSAKey servkey, hostkey;
struct MD5Context md5c;
static unsigned long supported_ciphers_mask, supported_auths_mask;
static int tried_publickey;
static unsigned char session_id[16];
- int cipher_type;
+ static int cipher_type;
static char username[100];
crBegin;
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");
break;
default:
if (((c >= ' ' && c <= '~') ||
- ((unsigned char) c >= 160)) && pos < 40) {
+ ((unsigned char) c >= 160))
+ && pos < sizeof(username)-1) {
username[pos++] = c;
c_write(&c, 1);
}
ssh1_read_bignum(pktin.body, &challenge);
{
char *agentreq, *q, *ret;
+ void *vret;
int len, retlen;
len = 1 + 4; /* message type, bit count */
len += ssh1_bignum_length(key.exponent);
memcpy(q, session_id, 16);
q += 16;
PUT_32BIT(q, 1); /* response format */
- agent_query(agentreq, len + 4, &ret, &retlen);
+ agent_query(agentreq, len + 4, &vret, &retlen);
+ ret = vret;
sfree(agentreq);
if (ret) {
if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
* because one was supplied on the command line
* which has already failed to work). Terminate.
*/
- logevent("No more passwords to try");
+ send_packet(SSH1_MSG_DISCONNECT,
+ PKT_STR, "No more passwords available to try",
+ PKT_END);
+ connection_fatal("Unable to authenticate");
ssh_state = SSH_STATE_CLOSED;
crReturn(1);
}
exit(0);
break;
default:
- if (((c >= ' ' && c <= '~') ||
- ((unsigned char) c >= 160))
- && pos < sizeof(password))
+ if (pos < sizeof(password)-1)
password[pos++] = c;
break;
}
c->closes = 1;
if (c->type == CHAN_X11) {
c->u.x11.s = NULL;
- logevent("X11 connection terminated");
+ logevent("Forwarded X11 connection terminated");
+ } else if (c->type == CHAN_SOCKDATA) {
+ 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);
}
}
}
}
+ {
+ char type, *e;
+ int n;
+ int sport,dport;
+ char sports[256], dports[256], host[256];
+ char buf[1024];
+
+ ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
+ /* Add port forwardings. */
+ e = cfg.portfwd;
+ while (*e) {
+ type = *e++;
+ n = 0;
+ while (*e && *e != '\t')
+ sports[n++] = *e++;
+ sports[n] = 0;
+ if (*e == '\t')
+ e++;
+ n = 0;
+ while (*e && *e != ':')
+ host[n++] = *e++;
+ host[n] = 0;
+ if (*e == ':')
+ e++;
+ n = 0;
+ while (*e)
+ dports[n++] = *e++;
+ dports[n] = 0;
+ e++;
+ dport = atoi(dports);
+ sport = atoi(sports);
+ if (sport && dport) {
+ if (type == 'L') {
+ pfd_addforward(host, dport, sport);
+ sprintf(buf, "Local port %d forwarding to %s:%d",
+ sport, host, dport);
+ logevent(buf);
+ } else {
+ struct ssh_rportfwd *pf;
+ pf = smalloc(sizeof(*pf));
+ strcpy(pf->dhost, host);
+ pf->dport = dport;
+ if (add234(ssh_rportfwds, pf) != pf) {
+ sprintf(buf,
+ "Duplicate remote port forwarding to %s:%d",
+ host, dport);
+ logevent(buf);
+ sfree(pf);
+ } else {
+ sprintf(buf, "Requesting remote port %d forward to %s:%d",
+ sport, host, dport);
+ logevent(buf);
+ send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
+ PKT_INT, sport,
+ PKT_STR, host,
+ PKT_INT, dport,
+ PKT_END);
+ }
+ }
+ }
+ }
+ }
+
if (!cfg.nopty) {
send_packet(SSH1_CMSG_REQUEST_PTY,
PKT_STR, cfg.termtype,
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 (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);
PKT_INT, c->remoteid, PKT_INT, c->localid,
PKT_END);
}
+ } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
+ /* 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;
+ int hostsize, port;
+ char host[256], buf[1024];
+ char *p, *h, *e;
+ c = smalloc(sizeof(struct ssh_channel));
+
+ hostsize = GET_32BIT(pktin.body+4);
+ for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
+ if (h+1 < host+sizeof(host))
+ *h++ = *p;
+ p++;
+ }
+ *h = 0;
+ port = GET_32BIT(p);
+
+ strcpy(pf.dhost, host);
+ pf.dport = port;
+
+ if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
+ sprintf(buf, "Rejected remote port open request for %s:%d",
+ host, port);
+ logevent(buf);
+ send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, GET_32BIT(pktin.body), PKT_END);
+ } else {
+ sprintf(buf, "Received remote port open request for %s:%d",
+ host, port);
+ logevent(buf);
+ e = pfd_newconnect(&c->u.pfd.s, host, port, c);
+ if (e != NULL) {
+ char buf[256];
+ sprintf(buf, "Port open failed: %s", e);
+ logevent(buf);
+ sfree(c);
+ send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
+ PKT_INT, GET_32BIT(pktin.body),
+ PKT_END);
+ } else {
+ 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,
+ PKT_INT, c->remoteid, PKT_INT,
+ c->localid, PKT_END);
+ logevent("Forwarded port opened successfully");
+ }
+ }
+
+ } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
+ 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) {
+ c->remoteid = localid;
+ c->type = CHAN_SOCKDATA;
+ pfd_confirm(c->u.pfd.s);
+ }
+
+ } 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. */
send_packet(pktin.type, PKT_INT, c->remoteid,
PKT_END);
if ((c->closes == 0) && (c->type == CHAN_X11)) {
- logevent("X11 connection closed");
+ 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;
if (c->closes == 3) {
del234(ssh_channels, c);
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:
+ 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 */
*/
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:
+ /* Not supported in SSH2; silently drop */
+ 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;
+ }
}
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;
+ }
}
ssh2_pkt_getstring(&str, &len); /* client->server mac */
for (i = 0; i < nmacs; i++) {
#endif
hkey = hostkey->newkey(hostkeydata, hostkeylen);
- if (!hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
- bombout(("Server failed host key check"));
+ if (!hkey ||
+ !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
+ bombout(("Server's host key did not match the signature supplied"));
crReturn(0);
}
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();
- c->v2.outbuflen -= len;
- memmove(c->v2.outbuffer, c->v2.outbuffer + len, c->v2.outbuflen);
- c->v2.remwindow -= len;
+ 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->v.v2.locwindow = newwin;
}
}
*/
static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
{
- static unsigned long remote_winsize;
- static unsigned long remote_maxpkt;
static enum {
AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
- AUTH_PASSWORD
+ AUTH_PASSWORD,
+ AUTH_KEYBOARD_INTERACTIVE
} method;
static enum {
AUTH_TYPE_NONE,
AUTH_TYPE_PUBLICKEY,
AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
- AUTH_TYPE_PASSWORD
+ AUTH_TYPE_PASSWORD,
+ AUTH_TYPE_KEYBOARD_INTERACTIVE,
+ AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
} type;
- static int gotit, need_pw, can_pubkey, can_passwd;
- static int tried_pubkey_config, tried_agent;
+ static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
+ static int tried_pubkey_config, tried_agent, tried_keyb_inter;
+ static int kbd_inter_running;
static int we_are_in;
+ static int num_prompts, echo;
static char username[100];
static char pwprompt[200];
static char password[100];
break;
default:
if (((c >= ' ' && c <= '~') ||
- ((unsigned char) c >= 160)) && pos < 40) {
+ ((unsigned char) c >= 160))
+ && pos < sizeof(username)-1) {
username[pos++] = c;
c_write(&c, 1);
}
tried_pubkey_config = FALSE;
tried_agent = FALSE;
+ tried_keyb_inter = FALSE;
+ kbd_inter_running = FALSE;
while (1) {
/*
break;
}
- if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
- bombout(
- ("Strange packet received during authentication: type %d",
+ if (kbd_inter_running &&
+ pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
+ /*
+ * This is a further prompt in keyboard-interactive
+ * authentication. Do nothing.
+ */
+ } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
+ bombout(("Strange packet received during authentication: type %d",
pktin.type));
crReturnV;
}
* we can look at the string in it and know what we can
* helpfully try next.
*/
- {
+ if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
char *methods;
int methlen;
ssh2_pkt_getstring(&methods, &methlen);
+ kbd_inter_running = FALSE;
if (!ssh2_pkt_getbool()) {
/*
* We have received an unequivocal Access
if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
c_write_str("Server refused our key\r\n");
logevent("Server refused public key");
+ } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
+ /* server declined keyboard-interactive; ignore */
} else {
c_write_str("Access denied\r\n");
logevent("Access denied");
in_commasep_string("publickey", methods, methlen);
can_passwd =
in_commasep_string("password", methods, methlen);
+ can_keyb_inter =
+ in_commasep_string("keyboard-interactive", methods, methlen);
}
method = 0;
static int pklen, alglen, commentlen;
static int siglen, retlen, len;
static char *q, *agentreq, *ret;
+ void *vret;
{
char buf[64];
q += pktout.length - 5;
/* And finally the (zero) flags word. */
PUT_32BIT(q, 0);
- agent_query(agentreq, len + 4, &ret, &retlen);
+ agent_query(agentreq, len + 4, &vret, &retlen);
+ ret = vret;
sfree(agentreq);
if (ret) {
if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
}
}
+ 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_passwd) {
method = AUTH_PASSWORD;
sprintf(pwprompt, "%.90s@%.90s's password: ", username,
* command line which has already failed to
* work). Terminate.
*/
- logevent("No more passwords to try");
+ ssh2_pkt_init(SSH2_MSG_DISCONNECT);
+ ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
+ ssh2_pkt_addstring
+ ("No more passwords available to try");
+ ssh2_pkt_addstring("en"); /* language tag */
+ ssh2_pkt_send();
+ connection_fatal("Unable to authenticate");
ssh_state = SSH_STATE_CLOSED;
crReturnV;
}
static int pos = 0;
static char c;
- c_write_str(pwprompt);
+ c_write_untrusted(pwprompt, strlen(pwprompt));
ssh_send_ok = 1;
pos = 0;
exit(0);
break;
default:
- if (((c >= ' ' && c <= '~') ||
- ((unsigned char) c >= 160))
- && pos < 40)
+ if (pos < sizeof(password)-1)
password[pos++] = c;
break;
}
ssh_pkt_defersend();
logevent("Sent password");
type = AUTH_TYPE_PASSWORD;
+ } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
+ ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
+ ssh2_pkt_adduint32(num_prompts);
+ ssh2_pkt_addstring(password);
+ memset(password, 0, sizeof(password));
+ ssh2_pkt_send();
+ type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
} else {
c_write_str
("No supported authentication methods left to try!\r\n");
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);
}
/*
+ * Enable port forwardings.
+ */
+ {
+ static char *e; /* preserve across crReturn */
+ char type;
+ int n;
+ int sport,dport;
+ char sports[256], dports[256], host[256];
+ char buf[1024];
+
+ ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
+ /* Add port forwardings. */
+ e = cfg.portfwd;
+ while (*e) {
+ type = *e++;
+ n = 0;
+ while (*e && *e != '\t')
+ sports[n++] = *e++;
+ sports[n] = 0;
+ if (*e == '\t')
+ e++;
+ n = 0;
+ while (*e && *e != ':')
+ host[n++] = *e++;
+ host[n] = 0;
+ if (*e == ':')
+ e++;
+ n = 0;
+ while (*e)
+ dports[n++] = *e++;
+ dports[n] = 0;
+ e++;
+ dport = atoi(dports);
+ sport = atoi(sports);
+ if (sport && dport) {
+ if (type == 'L') {
+ pfd_addforward(host, dport, sport);
+ sprintf(buf, "Local port %d forwarding to %s:%d",
+ sport, host, dport);
+ logevent(buf);
+ } else {
+ struct ssh_rportfwd *pf;
+ pf = smalloc(sizeof(*pf));
+ strcpy(pf->dhost, host);
+ pf->dport = dport;
+ pf->sport = sport;
+ if (add234(ssh_rportfwds, pf) != pf) {
+ sprintf(buf,
+ "Duplicate remote port forwarding to %s:%d",
+ host, dport);
+ logevent(buf);
+ sfree(pf);
+ } else {
+ sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
+ sport, host, dport);
+ logevent(buf);
+ ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
+ ssh2_pkt_addstring("tcpip-forward");
+ ssh2_pkt_addbool(1);/* want reply */
+ ssh2_pkt_addstring("127.0.0.1");
+ ssh2_pkt_adduint32(sport);
+ 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_REQUEST_SUCCESS) {
+ if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
+ bombout(("Server got confused by port forwarding request"));
+ crReturnV;
+ }
+ logevent("Server refused this port forwarding");
+ } else {
+ logevent("Remote port forwarding enabled");
+ }
+ }
+ }
+ }
+ }
+ }
+
+ /*
* Potentially enable agent forwarding.
*/
if (cfg.agentfwd && agent_exists()) {
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);
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);
}
/*
- * 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(("Server got confused by shell/command request"));
+ 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;
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:
+ 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;
sshfwd_close(c);
} else if (c->type == CHAN_AGENT) {
sshfwd_close(c);
+ } else if (c->type == CHAN_SOCKDATA) {
+ pfd_close(c->u.pfd.s);
+ sshfwd_close(c);
}
} else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
unsigned i = ssh2_pkt_getuint32();
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();
+ 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 confirming this */
+ c->remoteid = ssh2_pkt_getuint32();
+ c->type = CHAN_SOCKDATA;
+ c->closes = 0;
+ c->v.v2.remwindow = ssh2_pkt_getuint32();
+ c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
+ bufchain_init(&c->v.v2.outbuffer);
+ pfd_confirm(c->u.pfd.s);
+ } 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_OPEN) {
char *type;
int typelen;
char *error = NULL;
struct ssh_channel *c;
+ unsigned remid, winsize, pktsize;
ssh2_pkt_getstring(&type, &typelen);
c = smalloc(sizeof(struct ssh_channel));
+ remid = ssh2_pkt_getuint32();
+ winsize = ssh2_pkt_getuint32();
+ pktsize = ssh2_pkt_getuint32();
+
if (typelen == 3 && !memcmp(type, "x11", 3)) {
if (!ssh_X11_fwd_enabled)
error = "X11 forwarding is not enabled";
} else {
c->type = CHAN_X11;
}
+ } else if (typelen == 15 &&
+ !memcmp(type, "forwarded-tcpip", 15)) {
+ struct ssh_rportfwd pf, *realpf;
+ char *dummy;
+ int dummylen;
+ ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
+ pf.sport = ssh2_pkt_getuint32();
+ realpf = find234(ssh_rportfwds, &pf, NULL);
+ if (realpf == NULL) {
+ error = "Remote port is not recognised";
+ } else {
+ char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
+ realpf->dport, c);
+ char buf[1024];
+ sprintf(buf, "Received remote port open request for %s:%d",
+ realpf->dhost, realpf->dport);
+ logevent(buf);
+ if (e != NULL) {
+ sprintf(buf, "Port open failed: %s", e);
+ logevent(buf);
+ error = "Port open failed";
+ } else {
+ logevent("Forwarded port opened successfully");
+ c->type = CHAN_SOCKDATA;
+ }
+ }
} else if (typelen == 22 &&
!memcmp(type, "auth-agent@openssh.com", 3)) {
if (!ssh_agentfwd_enabled)
error = "Unsupported channel type requested";
}
- c->remoteid = ssh2_pkt_getuint32();
+ c->remoteid = remid;
if (error) {
ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
ssh2_pkt_adduint32(c->remoteid);
} else {
c->localid = alloc_channel_id();
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;
+ 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;
+ }
+ }
+ }
}
}
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);
if (p != NULL)
/*
* 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;
}
/*
}
}
+void *new_sock_channel(Socket s)
+{
+ struct ssh_channel *c;
+ c = smalloc(sizeof(struct ssh_channel));
+
+ if (c) {
+ c->remoteid = -1; /* to be set when open confirmed */
+ c->localid = alloc_channel_id();
+ c->closes = 0;
+ c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
+ c->u.pfd.s = s;
+ add234(ssh_channels, c);
+ }
+ 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;
+ char buf[1024];
+
+ sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
+ logevent(buf);
+
+ if (ssh_version == 1) {
+ send_packet(SSH1_MSG_PORT_OPEN,
+ PKT_INT, c->localid,
+ PKT_STR, hostname,
+ PKT_INT, port,
+ //PKT_STR, <org:orgport>,
+ PKT_END);
+ } else {
+ ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
+ ssh2_pkt_addstring("direct-tcpip");
+ ssh2_pkt_adduint32(c->localid);
+ 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);
+ /*
+ * We make up values for the originator data; partly it's
+ * too much hassle to keep track, and partly I'm not
+ * convinced the server should be told details like that
+ * about my local network configuration.
+ */
+ ssh2_pkt_addstring("client-side-connection");
+ ssh2_pkt_adduint32(0);
+ ssh2_pkt_send();
+ }
+}
+
+
static Socket ssh_socket(void)
{
return s;
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