X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/514702987c9252fcb0ab98882a6603b3bd0505ce..b3ebaa287b8a57f3d35675889adc86f6384eb458:/ssh.c

diff --git a/ssh.c b/ssh.c
index 115e902f..a2e74c0e 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1,4 +1,3 @@
-#include <windows.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
@@ -15,26 +14,6 @@
 #define TRUE 1
 #endif
 
-#define logevent(s) { logevent(s); \
-                      if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
-                      { fprintf(stderr, "%s\n", s); fflush(stderr); } }
-
-/* logevent, only printf-formatted. */
-void logeventf(char *fmt, ...)
-{
-    va_list ap;
-    char stuff[200];
-
-    va_start(ap, fmt);
-    vsprintf(stuff, fmt, ap);
-    va_end(ap);
-    logevent(stuff);
-}
-
-#define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
-                          (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
-                          logeventf msg, connection_fatal msg )
-
 #define SSH1_MSG_DISCONNECT                       1	/* 0x1 */
 #define SSH1_SMSG_PUBLIC_KEY                      2	/* 0x2 */
 #define SSH1_CMSG_SESSION_KEY                     3	/* 0x3 */
@@ -187,7 +166,7 @@ static const char *const ssh2_disconnect_reasons[] = {
 
 #define translate(x) if (type == x) return #x
 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
-char *ssh1_pkt_type(int type)
+static char *ssh1_pkt_type(int type)
 {
     translate(SSH1_MSG_DISCONNECT);
     translate(SSH1_SMSG_PUBLIC_KEY);
@@ -232,7 +211,7 @@ char *ssh1_pkt_type(int type)
     translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
     return "unknown";
 }
-char *ssh2_pkt_type(int pkt_ctx, int type)
+static char *ssh2_pkt_type(int pkt_ctx, int type)
 {
     translate(SSH2_MSG_DISCONNECT);
     translate(SSH2_MSG_IGNORE);
@@ -312,21 +291,6 @@ enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
 
 typedef struct ssh_tag *Ssh;
 
-extern char *x11_init(Socket *, char *, void *);
-extern void x11_close(Socket);
-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);
-
 static void ssh2_pkt_init(Ssh, int pkt_type);
 static void ssh2_pkt_addbool(Ssh, unsigned char value);
 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
@@ -334,7 +298,7 @@ static void ssh2_pkt_addstring_start(Ssh);
 static void ssh2_pkt_addstring_str(Ssh, char *data);
 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
 static void ssh2_pkt_addstring(Ssh, char *data);
-static char *ssh2_mpint_fmt(Bignum b, int *len);
+static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
 static void ssh2_pkt_addmp(Ssh, Bignum b);
 static int ssh2_pkt_construct(Ssh);
 static void ssh2_pkt_send(Ssh);
@@ -371,19 +335,28 @@ const static struct ssh_kex *kex_algs[] = {
 
 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
 
-static void nullmac_key(unsigned char *key)
+static void *nullmac_make_context(void)
+{
+    return NULL;
+}
+static void nullmac_free_context(void *handle)
 {
 }
-static void nullmac_generate(unsigned char *blk, int len,
+static void nullmac_key(void *handle, unsigned char *key)
+{
+}
+static void nullmac_generate(void *handle, unsigned char *blk, int len,
 			     unsigned long seq)
 {
 }
-static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
+static int nullmac_verify(void *handle, unsigned char *blk, int len,
+			  unsigned long seq)
 {
     return 1;
 }
 const static struct ssh_mac ssh_mac_none = {
-    nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
+    nullmac_make_context, nullmac_free_context, nullmac_key,
+    nullmac_generate, nullmac_verify, "none", 0
 };
 const static struct ssh_mac *macs[] = {
     &ssh_sha1, &ssh_md5, &ssh_mac_none
@@ -392,23 +365,27 @@ const static struct ssh_mac *buggymacs[] = {
     &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
 };
 
-static void ssh_comp_none_init(void)
+static void *ssh_comp_none_init(void)
 {
+    return NULL;
 }
-static int ssh_comp_none_block(unsigned char *block, int len,
+static void ssh_comp_none_cleanup(void *handle)
+{
+}
+static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
 			       unsigned char **outblock, int *outlen)
 {
     return 0;
 }
-static int ssh_comp_none_disable(void)
+static int ssh_comp_none_disable(void *handle)
 {
     return 0;
 }
 const static struct ssh_compress ssh_comp_none = {
     "none",
-    ssh_comp_none_init, ssh_comp_none_block,
-    ssh_comp_none_init, ssh_comp_none_block,
-    ssh_comp_none_disable
+    ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
+    ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
+    ssh_comp_none_disable, NULL
 };
 extern const struct ssh_compress ssh_zlib;
 const static struct ssh_compress *compressions[] = {
@@ -542,6 +519,9 @@ struct ssh_tag {
 
     Socket s;
 
+    void *ldisc;
+    void *logctx;
+
     unsigned char session_key[32];
     int v1_compressing;
     int v1_remote_protoflags;
@@ -550,12 +530,18 @@ struct ssh_tag {
     int X11_fwd_enabled;
     int remote_bugs;
     const struct ssh_cipher *cipher;
+    void *v1_cipher_ctx;
+    void *crcda_ctx;
     const struct ssh2_cipher *cscipher, *sccipher;
+    void *cs_cipher_ctx, *sc_cipher_ctx;
     const struct ssh_mac *csmac, *scmac;
+    void *cs_mac_ctx, *sc_mac_ctx;
     const struct ssh_compress *cscomp, *sccomp;
+    void *cs_comp_ctx, *sc_comp_ctx;
     const struct ssh_kex *kex;
     const struct ssh_signkey *hostkey;
     unsigned char v2_session_id[20];
+    void *kex_ctx;
 
     char *savedhost;
     int savedport;
@@ -606,6 +592,8 @@ struct ssh_tag {
     char *portfwd_strptr;
     int pkt_ctx;
 
+    void *x11auth;
+
     int version;
     int v1_throttle_count;
     int overall_bufsize;
@@ -634,6 +622,25 @@ struct ssh_tag {
     int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
 };
 
+#define logevent(s) logevent(ssh->frontend, s)
+
+/* logevent, only printf-formatted. */
+static void logeventf(Ssh ssh, char *fmt, ...)
+{
+    va_list ap;
+    char *buf;
+
+    va_start(ap, fmt);
+    buf = dupvprintf(fmt, ap);
+    va_end(ap);
+    logevent(buf);
+    sfree(buf);
+}
+
+#define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
+                          (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
+                          logeventf msg, connection_fatal msg )
+
 static int ssh_channelcmp(void *av, void *bv)
 {
     struct ssh_channel *a = (struct ssh_channel *) av;
@@ -797,18 +804,19 @@ static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
 	st->to_read -= st->chunk;
     }
 
-    if (ssh->cipher && detect_attack(ssh->pktin.data, st->biglen, NULL)) {
-        bombout(("Network attack (CRC compensation) detected!"));
+    if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
+				     st->biglen, NULL)) {
+        bombout((ssh,"Network attack (CRC compensation) detected!"));
         crReturn(0);
     }
 
     if (ssh->cipher)
-	ssh->cipher->decrypt(ssh->pktin.data, st->biglen);
+	ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
 
     st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
     st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
     if (st->gotcrc != st->realcrc) {
-	bombout(("Incorrect CRC received on packet"));
+	bombout((ssh,"Incorrect CRC received on packet"));
 	crReturn(0);
     }
 
@@ -817,7 +825,8 @@ static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
     if (ssh->v1_compressing) {
 	unsigned char *decompblk;
 	int decomplen;
-	zlib_decompress_block(ssh->pktin.body - 1, ssh->pktin.length + 1,
+	zlib_decompress_block(ssh->sc_comp_ctx,
+			      ssh->pktin.body - 1, ssh->pktin.length + 1,
 			      &decompblk, &decomplen);
 
 	if (ssh->pktin.maxlen < st->pad + decomplen) {
@@ -834,8 +843,11 @@ static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
 
     ssh->pktin.type = ssh->pktin.body[-1];
 
-    log_packet(PKT_INCOMING, ssh->pktin.type, ssh1_pkt_type(ssh->pktin.type),
-	       ssh->pktin.body, ssh->pktin.length);
+    if (ssh->logctx)
+	log_packet(ssh->logctx,
+		   PKT_INCOMING, ssh->pktin.type,
+		   ssh1_pkt_type(ssh->pktin.type),
+		   ssh->pktin.body, ssh->pktin.length);
 
     if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
 	ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
@@ -844,7 +856,7 @@ static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
 	ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
 	long stringlen = GET_32BIT(ssh->pktin.body);
 	if (stringlen + 4 != ssh->pktin.length) {
-	    bombout(("Received data packet with bogus string length"));
+	    bombout((ssh,"Received data packet with bogus string length"));
 	    crReturn(0);
 	}
     }
@@ -877,7 +889,7 @@ static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
 	memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
 	buf[nowlen + msglen] = '\0';
 	/* logevent(buf); (this is now done within the bombout macro) */
-	bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
+	bombout((ssh,"Server sent disconnect message:\n\"%s\"", buf+nowlen));
 	crReturn(0);
     }
 
@@ -917,7 +929,8 @@ static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
     }
 
     if (ssh->sccipher)
-	ssh->sccipher->decrypt(ssh->pktin.data, st->cipherblk);
+	ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
+			       ssh->pktin.data, st->cipherblk);
 
     /*
      * Now get the length and padding figures.
@@ -930,7 +943,7 @@ static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
      * do us any more damage.
      */
     if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
-	bombout(("Incoming packet was garbled on decryption"));
+	bombout((ssh,"Incoming packet was garbled on decryption"));
 	crReturn(0);
     }
 
@@ -968,16 +981,17 @@ static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
     }
     /* Decrypt everything _except_ the MAC. */
     if (ssh->sccipher)
-	ssh->sccipher->decrypt(ssh->pktin.data + st->cipherblk,
+	ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
+			       ssh->pktin.data + st->cipherblk,
 			       st->packetlen - st->cipherblk);
 
     /*
      * Check the MAC.
      */
     if (ssh->scmac
-	&& !ssh->scmac->verify(ssh->pktin.data, st->len + 4,
+	&& !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
 			       st->incoming_sequence)) {
-	bombout(("Incorrect MAC received on packet"));
+	bombout((ssh,"Incorrect MAC received on packet"));
 	crReturn(0);
     }
     st->incoming_sequence++;	       /* whether or not we MACed */
@@ -989,7 +1003,8 @@ static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
 	unsigned char *newpayload;
 	int newlen;
 	if (ssh->sccomp &&
-	    ssh->sccomp->decompress(ssh->pktin.data + 5, ssh->pktin.length - 5,
+	    ssh->sccomp->decompress(ssh->sc_comp_ctx,
+				    ssh->pktin.data + 5, ssh->pktin.length - 5,
 				    &newpayload, &newlen)) {
 	    if (ssh->pktin.maxlen < newlen + 5) {
 		ssh->pktin.maxlen = newlen + 5;
@@ -1005,9 +1020,10 @@ static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
     ssh->pktin.savedpos = 6;
     ssh->pktin.type = ssh->pktin.data[5];
 
-    log_packet(PKT_INCOMING, ssh->pktin.type,
-	       ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
-	       ssh->pktin.data+6, ssh->pktin.length-6);
+    if (ssh->logctx)
+	log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
+		   ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
+		   ssh->pktin.data+6, ssh->pktin.length-6);
 
     switch (ssh->pktin.type) {
         /*
@@ -1016,30 +1032,29 @@ static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
       case SSH2_MSG_DISCONNECT:
         {
             /* log reason code in disconnect message */
-            char buf[256];
+            char *buf;
+	    int nowlen;
             int reason = GET_32BIT(ssh->pktin.data + 6);
             unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
-            unsigned nowlen;
+
             if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
-                sprintf(buf, "Received disconnect message (%s)",
-                        ssh2_disconnect_reasons[reason]);
+                buf = dupprintf("Received disconnect message (%s)",
+				ssh2_disconnect_reasons[reason]);
             } else {
-                sprintf(buf, "Received disconnect message (unknown type %d)",
-                        reason);
+                buf = dupprintf("Received disconnect message (unknown"
+				" type %d)", reason);
             }
             logevent(buf);
-            strcpy(buf, "Disconnection message text: ");
-            nowlen = strlen(buf);
-            if (msglen > sizeof(buf) - nowlen - 1)
-                msglen = sizeof(buf) - nowlen - 1;
-            memcpy(buf + nowlen, ssh->pktin.data + 14, msglen);
-            buf[nowlen + msglen] = '\0';
+	    sfree(buf);
+            buf = dupprintf("Disconnection message text: %n%.*s",
+			    &nowlen, msglen, ssh->pktin.data + 14);
             logevent(buf);
-            bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
+            bombout((ssh,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
                      reason,
                      (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
                      ssh2_disconnect_reasons[reason] : "unknown",
                      buf+nowlen));
+	    sfree(buf);
             crReturn(0);
         }
         break;
@@ -1148,13 +1163,16 @@ static int s_wrpkt_prepare(Ssh ssh)
 
     ssh->pktout.body[-1] = ssh->pktout.type;
 
-    log_packet(PKT_OUTGOING, ssh->pktout.type, ssh1_pkt_type(ssh->pktout.type),
-	       ssh->pktout.body, ssh->pktout.length);
+    if (ssh->logctx)
+	log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
+		   ssh1_pkt_type(ssh->pktout.type),
+		   ssh->pktout.body, ssh->pktout.length);
 
     if (ssh->v1_compressing) {
 	unsigned char *compblk;
 	int complen;
-	zlib_compress_block(ssh->pktout.body - 1, ssh->pktout.length + 1,
+	zlib_compress_block(ssh->cs_comp_ctx,
+			    ssh->pktout.body - 1, ssh->pktout.length + 1,
 			    &compblk, &complen);
 	ssh1_pktout_size(ssh, complen - 1);
 	memcpy(ssh->pktout.body - 1, compblk, complen);
@@ -1172,7 +1190,7 @@ static int s_wrpkt_prepare(Ssh ssh)
     PUT_32BIT(ssh->pktout.data, len);
 
     if (ssh->cipher)
-	ssh->cipher->encrypt(ssh->pktout.data + 4, biglen);
+	ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
 
     return biglen + 4;
 }
@@ -1181,7 +1199,7 @@ static void s_wrpkt(Ssh ssh)
 {
     int len, backlog;
     len = s_wrpkt_prepare(ssh);
-    backlog = sk_write(ssh->s, ssh->pktout.data, len);
+    backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
     if (backlog > SSH_MAX_BACKLOG)
 	ssh_throttle_all(ssh, 1, backlog);
 }
@@ -1217,7 +1235,7 @@ static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
 	    pktlen += 4;
 	    break;
 	  case PKT_CHAR:
-	    (void) va_arg(ap1, char);
+	    (void) va_arg(ap1, int);
 	    pktlen++;
 	    break;
 	  case PKT_DATA:
@@ -1227,7 +1245,7 @@ static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
 	    break;
 	  case PKT_STR:
 	    argp = va_arg(ap1, unsigned char *);
-	    arglen = strlen(argp);
+	    arglen = strlen((char *)argp);
 	    pktlen += 4 + arglen;
 	    break;
 	  case PKT_BIGNUM:
@@ -1250,7 +1268,7 @@ static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
 	    p += 4;
 	    break;
 	  case PKT_CHAR:
-	    argchar = va_arg(ap2, unsigned char);
+	    argchar = (unsigned char) va_arg(ap2, int);
 	    *p = argchar;
 	    p++;
 	    break;
@@ -1262,7 +1280,7 @@ static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
 	    break;
 	  case PKT_STR:
 	    argp = va_arg(ap2, unsigned char *);
-	    arglen = strlen(argp);
+	    arglen = strlen((char *)argp);
 	    PUT_32BIT(p, arglen);
 	    memcpy(p + 4, argp, arglen);
 	    p += 4 + arglen;
@@ -1393,7 +1411,7 @@ static void ssh2_pkt_addstring(Ssh ssh, char *data)
     ssh2_pkt_addstring_start(ssh);
     ssh2_pkt_addstring_str(ssh, data);
 }
-static char *ssh2_mpint_fmt(Bignum b, int *len)
+static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
 {
     unsigned char *p;
     int i, n = (bignum_bitcount(b) + 7) / 8;
@@ -1416,7 +1434,7 @@ static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
     int len;
     p = ssh2_mpint_fmt(b, &len);
     ssh2_pkt_addstring_start(ssh);
-    ssh2_pkt_addstring_data(ssh, p, len);
+    ssh2_pkt_addstring_data(ssh, (char *)p, len);
     sfree(p);
 }
 
@@ -1429,9 +1447,10 @@ static int ssh2_pkt_construct(Ssh ssh)
 {
     int cipherblk, maclen, padding, i;
 
-    log_packet(PKT_OUTGOING, ssh->pktout.data[5],
-	       ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
-	       ssh->pktout.data + 6, ssh->pktout.length - 6);
+    if (ssh->logctx)
+	log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
+		   ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
+		   ssh->pktout.data + 6, ssh->pktout.length - 6);
 
     /*
      * Compress packet payload.
@@ -1440,7 +1459,8 @@ static int ssh2_pkt_construct(Ssh ssh)
 	unsigned char *newpayload;
 	int newlen;
 	if (ssh->cscomp &&
-	    ssh->cscomp->compress(ssh->pktout.data + 5, ssh->pktout.length - 5,
+	    ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
+				  ssh->pktout.length - 5,
 				  &newpayload, &newlen)) {
 	    ssh->pktout.length = 5;
 	    ssh2_pkt_adddata(ssh, newpayload, newlen);
@@ -1464,12 +1484,14 @@ static int ssh2_pkt_construct(Ssh ssh)
 	ssh->pktout.data[ssh->pktout.length + i] = random_byte();
     PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
     if (ssh->csmac)
-	ssh->csmac->generate(ssh->pktout.data, ssh->pktout.length + padding,
+	ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
+			     ssh->pktout.length + padding,
 			     ssh->v2_outgoing_sequence);
     ssh->v2_outgoing_sequence++;       /* whether or not we MACed */
 
     if (ssh->cscipher)
-	ssh->cscipher->encrypt(ssh->pktout.data, ssh->pktout.length + padding);
+	ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
+			       ssh->pktout.data, ssh->pktout.length + padding);
 
     /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
     return ssh->pktout.length + padding + maclen;
@@ -1483,7 +1505,7 @@ static void ssh2_pkt_send(Ssh ssh)
     int len;
     int backlog;
     len = ssh2_pkt_construct(ssh);
-    backlog = sk_write(ssh->s, ssh->pktout.data, len);
+    backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
     if (backlog > SSH_MAX_BACKLOG)
 	ssh_throttle_all(ssh, 1, backlog);
 }
@@ -1518,7 +1540,8 @@ static void ssh2_pkt_defer(Ssh ssh)
 static void ssh_pkt_defersend(Ssh ssh)
 {
     int backlog;
-    backlog = sk_write(ssh->s, ssh->deferred_send_data, ssh->deferred_len);
+    backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
+		       ssh->deferred_len);
     ssh->deferred_len = ssh->deferred_size = 0;
     sfree(ssh->deferred_send_data);
     ssh->deferred_send_data = NULL;
@@ -1572,15 +1595,19 @@ static int ssh2_pkt_getbool(Ssh ssh)
 }
 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
 {
+    int len;
     *p = NULL;
     *length = 0;
     if (ssh->pktin.length - ssh->pktin.savedpos < 4)
 	return;
-    *length = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
+    len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
+    if (len < 0)
+	return;
+    *length = len;
     ssh->pktin.savedpos += 4;
     if (ssh->pktin.length - ssh->pktin.savedpos < *length)
 	return;
-    *p = ssh->pktin.data + ssh->pktin.savedpos;
+    *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
     ssh->pktin.savedpos += *length;
 }
 static Bignum ssh2_pkt_getmp(Ssh ssh)
@@ -1593,10 +1620,10 @@ static Bignum ssh2_pkt_getmp(Ssh ssh)
     if (!p)
 	return NULL;
     if (p[0] & 0x80) {
-	bombout(("internal error: Can't handle negative mpints"));
+	bombout((ssh,"internal error: Can't handle negative mpints"));
 	return NULL;
     }
-    b = bignum_from_bytes(p, length);
+    b = bignum_from_bytes((unsigned char *)p, length);
     return b;
 }
 
@@ -1646,18 +1673,18 @@ static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
 	if (len != siglen) {
 	    unsigned char newlen[4];
 	    ssh2_pkt_addstring_start(ssh);
-	    ssh2_pkt_addstring_data(ssh, sigblob, pos);
+	    ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
 	    /* dmemdump(sigblob, pos); */
 	    pos += 4;		       /* point to start of actual sig */
 	    PUT_32BIT(newlen, len);
-	    ssh2_pkt_addstring_data(ssh, newlen, 4);
+	    ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
 	    /* dmemdump(newlen, 4); */
 	    newlen[0] = 0;
 	    while (len-- > siglen) {
-		ssh2_pkt_addstring_data(ssh, newlen, 1);
+		ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
 		/* dmemdump(newlen, 1); */
 	    }
-	    ssh2_pkt_addstring_data(ssh, sigblob+pos, siglen);
+	    ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
 	    /* dmemdump(sigblob+pos, siglen); */
 	    return;
 	}
@@ -1666,7 +1693,7 @@ static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
     }
 
     ssh2_pkt_addstring_start(ssh);
-    ssh2_pkt_addstring_data(ssh, sigblob, sigblob_len);
+    ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
 }
 
 /*
@@ -1724,9 +1751,9 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring)
 
     if (cfg.sshbug_hmac2 == BUG_ON ||
 	(cfg.sshbug_hmac2 == BUG_AUTO &&
-	 (!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)))) {
+	 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
+	  wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
+	  wc_match("2.1 *", imp)))) {
 	/*
 	 * These versions have the HMAC bug.
 	 */
@@ -1736,7 +1763,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring)
 
     if (cfg.sshbug_derivekey2 == BUG_ON ||
 	(cfg.sshbug_derivekey2 == BUG_AUTO &&
-	 (!strncmp(imp, "2.0.", 4)))) {
+	 (wc_match("2.0.0*", imp) || wc_match("2.0.1[01]*", imp) ))) {
 	/*
 	 * These versions have the key-derivation bug (failing to
 	 * include the literal shared secret in the hashes that
@@ -1748,8 +1775,8 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring)
 
     if (cfg.sshbug_rsapad2 == BUG_ON ||
 	(cfg.sshbug_rsapad2 == BUG_AUTO &&
-	 ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
-	  (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')))){
+	 (wc_match("OpenSSH_2.[5-9]*", imp) ||
+	  wc_match("OpenSSH_3.[0-2]*", imp)))) {
 	/*
 	 * These versions have the SSH2 RSA padding bug.
 	 */
@@ -1759,7 +1786,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring)
 
     if (cfg.sshbug_dhgex2 == BUG_ON) {
 	/*
-	 * These versions have the SSH2 DH GEX bug.
+	 * User specified the SSH2 DH GEX bug.
 	 */
 	ssh->remote_bugs |= BUG_SSH2_DH_GEX;
 	logevent("We believe remote version has SSH2 DH group exchange bug");
@@ -1817,7 +1844,7 @@ static int do_ssh_init(Ssh ssh, unsigned char c)
 		s->i = -1;
 	    } else if (s->i < sizeof(s->version) - 1)
 		s->version[s->i++] = c;
-	} else if (c == '\n')
+	} else if (c == '\012')
 	    break;
     }
 
@@ -1845,11 +1872,11 @@ static int do_ssh_init(Ssh ssh, unsigned char c)
     s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
 
     if (cfg.sshprot == 0 && !s->proto1) {
-	bombout(("SSH protocol version 1 required by user but not provided by server"));
+	bombout((ssh,"SSH protocol version 1 required by user but not provided by server"));
 	crReturn(0);
     }
     if (cfg.sshprot == 3 && !s->proto2) {
-	bombout(("SSH protocol version 2 required by user but not provided by server"));
+	bombout((ssh,"SSH protocol version 2 required by user but not provided by server"));
 	crReturn(0);
     }
 
@@ -1867,7 +1894,7 @@ static int do_ssh_init(Ssh ssh, unsigned char c)
 	sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
 	sprintf(vlog, "We claim version: %s", verstring);
 	logevent(vlog);
-	strcat(verstring, "\n");
+	strcat(verstring, "\012");
 	logevent("Using SSH protocol version 2");
 	sk_write(ssh->s, verstring, strlen(verstring));
 	ssh->protocol = ssh2_protocol;
@@ -1883,7 +1910,7 @@ static int do_ssh_init(Ssh ssh, unsigned char c)
 		sshver);
 	sprintf(vlog, "We claim version: %s", verstring);
 	logevent(vlog);
-	strcat(verstring, "\n");
+	strcat(verstring, "\012");
 
 	logevent("Using SSH protocol version 1");
 	sk_write(ssh->s, verstring, strlen(verstring));
@@ -1956,7 +1983,7 @@ static int ssh_closing(Plug plug, char *error_msg, int error_code,
     if (error_msg) {
 	/* A socket error has occurred. */
 	logevent(error_msg);
-	connection_fatal(error_msg);
+	connection_fatal(ssh->frontend, error_msg);
     } else {
 	/* Otherwise, the remote side closed the connection normally. */
     }
@@ -1966,7 +1993,7 @@ static int ssh_closing(Plug plug, char *error_msg, int error_code,
 static int ssh_receive(Plug plug, int urgent, char *data, int len)
 {
     Ssh ssh = (Ssh) plug;
-    ssh_gotdata(ssh, data, len);
+    ssh_gotdata(ssh, (unsigned char *)data, len);
     if (ssh->state == SSH_STATE_CLOSED) {
 	if (ssh->s) {
 	    sk_close(ssh->s);
@@ -2019,27 +2046,22 @@ static char *connect_to_host(Ssh ssh, char *host, int port,
     /*
      * 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)))
+    logeventf(ssh, "Looking up host \"%s\"", host);
+    addr = name_lookup(host, port, realhost);
+    if ((err = sk_addr_error(addr)) != NULL)
 	return err;
 
     /*
      * Open socket.
      */
     {
-	char buf[200], addrbuf[100];
+	char addrbuf[100];
 	sk_getaddr(addr, addrbuf, 100);
-	sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
-	logevent(buf);
+	logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
     }
     ssh->fn = &fn_table;
     ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
-    if ((err = sk_socket_error(ssh->s))) {
+    if ((err = sk_socket_error(ssh->s)) != NULL) {
 	ssh->s = NULL;
 	return err;
     }
@@ -2103,7 +2125,7 @@ static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
  */
 
 /* Set up a username or password input loop on a given buffer. */
-void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
+static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
 {
     ssh->userpass_input_buffer = buffer;
     ssh->userpass_input_buflen = buflen;
@@ -2117,7 +2139,7 @@ void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
  * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
  * for inconclusive (keep waiting for more input please).
  */
-int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
+static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
 {
     char c;
 
@@ -2205,7 +2227,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	crWaitUntil(ispkt);
 
     if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
-	bombout(("Public key packet not received"));
+	bombout((ssh,"Public key packet not received"));
 	crReturn(0);
     }
 
@@ -2266,7 +2288,8 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	    fatalbox("Out of memory");
 	rsastr_fmt(keystr, &hostkey);
 	rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
-	verify_ssh_host_key(ssh->savedhost, ssh->savedport, "rsa", keystr,
+	verify_ssh_host_key(ssh->frontend,
+			    ssh->savedhost, ssh->savedport, "rsa", keystr,
 			    fingerprint);
 	sfree(keystr);
     }
@@ -2314,17 +2337,17 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	}
 	if (!cipher_chosen) {
 	    if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
-		bombout(("Server violates SSH 1 protocol by not "
+		bombout((ssh,"Server violates SSH 1 protocol by not "
 			 "supporting 3DES encryption"));
 	    else
 		/* shouldn't happen */
-		bombout(("No supported ciphers found"));
+		bombout((ssh,"No supported ciphers found"));
 	    crReturn(0);
 	}
 
 	/* Warn about chosen cipher if necessary. */
 	if (warn)
-	    askcipher(cipher_string, 0);
+	    askcipher(ssh->frontend, cipher_string, 0);
     }
 
     switch (s->cipher_type) {
@@ -2353,12 +2376,17 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
     ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
 		   s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
 		   &ssh_3des);
-    ssh->cipher->sesskey(ssh->session_key);
+    ssh->v1_cipher_ctx = ssh->cipher->make_context();
+    ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
+    logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
+
+    ssh->crcda_ctx = crcda_make_context();
+    logevent("Installing CRC compensation attack detector");
 
     crWaitUntil(ispkt);
 
     if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
-	bombout(("Encryption not successfully enabled"));
+	bombout((ssh,"Encryption not successfully enabled"));
 	crReturn(0);
     }
 
@@ -2472,7 +2500,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		    s->p += ssh1_read_bignum(s->p, &s->key.modulus);
 		    s->commentlen = GET_32BIT(s->p);
 		    s->p += 4;
-		    s->commentp = s->p;
+		    s->commentp = (char *)s->p;
 		    s->p += s->commentlen;
 		    send_packet(ssh, SSH1_CMSG_AUTH_RSA,
 				PKT_BIGNUM, s->key.modulus, PKT_END);
@@ -2614,8 +2642,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	    char msgbuf[256];
 	    if (flags & FLAG_VERBOSE)
 		c_write_str(ssh, "Trying public key authentication.\r\n");
-	    sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
-	    logevent(msgbuf);
+	    logeventf(ssh, "Trying public key \"%s\"", cfg.keyfile);
 	    type = key_type(cfg.keyfile);
 	    if (type != SSH_KEYTYPE_SSH1) {
 		sprintf(msgbuf, "Key is of wrong type (%s)",
@@ -2652,7 +2679,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 			    PKT_STR, "No more passwords available to try",
 			    PKT_END);
 		logevent("Unable to authenticate");
-		connection_fatal("Unable to authenticate");
+		connection_fatal(ssh->frontend, "Unable to authenticate");
 		ssh->state = SSH_STATE_CLOSED;
 		crReturn(1);
 	    }
@@ -2708,7 +2735,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		continue;	       /* go and try password */
 	    }
 	    if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
-		bombout(("Bizarre response to offer of public key"));
+		bombout((ssh,"Bizarre response to offer of public key"));
 		crReturn(0);
 	    }
 
@@ -2744,7 +2771,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 				" our public key.\r\n");
 		continue;	       /* go and try password */
 	    } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
-		bombout(("Bizarre response to RSA authentication response"));
+		bombout((ssh,"Bizarre response to RSA authentication response"));
 		crReturn(0);
 	    }
 
@@ -2877,7 +2904,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		c_write_str(ssh, "Access denied\r\n");
 	    logevent("Authentication refused");
 	} else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
-	    bombout(("Strange packet received, type %d", ssh->pktin.type));
+	    bombout((ssh,"Strange packet received, type %d", ssh->pktin.type));
 	    crReturn(0);
 	}
     }
@@ -2977,7 +3004,7 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	} while (!ispkt);
 	if (ssh->pktin.type != SSH1_SMSG_SUCCESS
 	    && ssh->pktin.type != SSH1_SMSG_FAILURE) {
-	    bombout(("Protocol confusion"));
+	    bombout((ssh,"Protocol confusion"));
 	    crReturnV;
 	} else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
 	    logevent("Agent forwarding refused");
@@ -2990,11 +3017,14 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
     if (cfg.x11_forward) {
 	char proto[20], data[64];
 	logevent("Requesting X11 forwarding");
-	x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
+	ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
+				       data, sizeof(data), cfg.x11_auth);
+        x11_get_real_auth(ssh->x11auth, cfg.x11_display);
 	if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
 	    send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
 			PKT_STR, proto, PKT_STR, data,
-			PKT_INT, 0, PKT_END);
+			PKT_INT, x11_get_screen_number(cfg.x11_display),
+			PKT_END);
 	} else {
 	    send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
 			PKT_STR, proto, PKT_STR, data, PKT_END);
@@ -3004,7 +3034,7 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	} while (!ispkt);
 	if (ssh->pktin.type != SSH1_SMSG_SUCCESS
 	    && ssh->pktin.type != SSH1_SMSG_FAILURE) {
-	    bombout(("Protocol confusion"));
+	    bombout((ssh,"Protocol confusion"));
 	    crReturnV;
 	} else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
 	    logevent("X11 forwarding refused");
@@ -3018,91 +3048,104 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	char type;
 	int n;
 	int sport,dport,sserv,dserv;
-	char sports[256], dports[256], host[256];
-	char buf[1024];
-	struct servent *se;
+	char sports[256], dports[256], saddr[256], host[256];
 
 	ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
         /* Add port forwardings. */
 	ssh->portfwd_strptr = cfg.portfwd;
 	while (*ssh->portfwd_strptr) {
 	    type = *ssh->portfwd_strptr++;
+	    saddr[0] = '\0';
 	    n = 0;
-	    while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
-		sports[n++] = *ssh->portfwd_strptr++;
+	    while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
+		if (*ssh->portfwd_strptr == ':') {
+		    /*
+		     * We've seen a colon in the middle of the
+		     * source port number. This means that
+		     * everything we've seen until now is the
+		     * source _address_, so we'll move it into
+		     * saddr and start sports from the beginning
+		     * again.
+		     */
+		    ssh->portfwd_strptr++;
+		    sports[n] = '\0';
+		    strcpy(saddr, sports);
+		    n = 0;
+		}
+		if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
+	    }
 	    sports[n] = 0;
 	    if (*ssh->portfwd_strptr == '\t')
 		ssh->portfwd_strptr++;
 	    n = 0;
-	    while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
-		host[n++] = *ssh->portfwd_strptr++;
+	    while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
+		if (n < 255) host[n++] = *ssh->portfwd_strptr++;
+	    }
 	    host[n] = 0;
 	    if (*ssh->portfwd_strptr == ':')
 		ssh->portfwd_strptr++;
 	    n = 0;
-	    while (*ssh->portfwd_strptr)
-		dports[n++] = *ssh->portfwd_strptr++;
+	    while (*ssh->portfwd_strptr) {
+		if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
+	    }
 	    dports[n] = 0;
 	    ssh->portfwd_strptr++;
 	    dport = atoi(dports);
 	    dserv = 0;
 	    if (dport == 0) {
 		dserv = 1;
-		se = getservbyname(dports, NULL);
-		if (se != NULL) {
-		    dport = ntohs(se->s_port);
-		} else {
-		    sprintf(buf,
-			    "Service lookup failed for destination port \"%s\"",
-			    dports);
-		    logevent(buf);
+		dport = net_service_lookup(dports);
+		if (!dport) {
+		    logeventf(ssh, "Service lookup failed for"
+			      " destination port \"%s\"", dports);
 		}
 	    }
 	    sport = atoi(sports);
 	    sserv = 0;
 	    if (sport == 0) {
 		sserv = 1;
-		se = getservbyname(sports, NULL);
-		if (se != NULL) {
-		    sport = ntohs(se->s_port);
-		} else {
-		    sprintf(buf,
-			    "Service lookup failed for source port \"%s\"",
-			    sports);
-		    logevent(buf);
+		sport = net_service_lookup(sports);
+		if (!sport) {
+		    logeventf(ssh, "Service lookup failed for source"
+			      " port \"%s\"", sports);
 		}
 	    }
 	    if (sport && dport) {
 		if (type == 'L') {
-		    pfd_addforward(host, dport, sport);
-		    sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
-			    " %s:%.*s%.*s%d%.*s",
-			    sserv ? strlen(sports) : 0, sports,
-			    sserv, "(", sport, sserv, ")",
-			    host,
-			    dserv ? strlen(dports) : 0, dports,
-			    dserv, "(", dport, dserv, ")");
-		    logevent(buf);
+		    pfd_addforward(host, dport, *saddr ? saddr : NULL,
+				   sport, ssh);
+		    logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
+			      " forwarding to %s:%.*s%.*s%d%.*s",
+			      (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
+			      (int)(*saddr?1:0), ":",
+			      (int)(sserv ? strlen(sports) : 0), sports,
+			      sserv, "(", sport, sserv, ")",
+			      host,
+			      (int)(dserv ? strlen(dports) : 0), dports,
+			      dserv, "(", dport, dserv, ")");
 		} else {
 		    struct ssh_rportfwd *pf;
 		    pf = smalloc(sizeof(*pf));
 		    strcpy(pf->dhost, host);
 		    pf->dport = dport;
+		    if (saddr) {
+			logeventf(ssh,
+				  "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
+				  saddr, sport);
+		    }
 		    if (add234(ssh->rportfwds, pf) != pf) {
-			sprintf(buf, 
-				"Duplicate remote port forwarding to %s:%d",
-				host, dport);
-			logevent(buf);
+			logeventf(ssh, 
+				  "Duplicate remote port forwarding to %s:%d",
+				  host, dport);
 			sfree(pf);
 		    } else {
-			sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
-				" forward to %s:%.*s%.*s%d%.*s",
-			    sserv ? strlen(sports) : 0, sports,
-			    sserv, "(", sport, sserv, ")",
-			    host,
-			    dserv ? strlen(dports) : 0, dports,
-			    dserv, "(", dport, dserv, ")");
-			logevent(buf);
+			logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
+				  " forward to %s:%.*s%.*s%d%.*s",
+				  (int)(sserv ? strlen(sports) : 0), sports,
+				  sserv, "(", sport, sserv, ")",
+				  host,
+				  (int)(dserv ? strlen(dports) : 0), dports,
+				  dserv, "(", dport, dserv, ")");
 			send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
 				    PKT_INT, sport,
 				    PKT_STR, host,
@@ -3113,7 +3156,7 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 			} while (!ispkt);
 			if (ssh->pktin.type != SSH1_SMSG_SUCCESS
 			    && ssh->pktin.type != SSH1_SMSG_FAILURE) {
-			    bombout(("Protocol confusion"));
+			    bombout((ssh,"Protocol confusion"));
 			    crReturnV;
 			} else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
 			    c_write_str(ssh, "Server refused port"
@@ -3138,7 +3181,7 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	} while (!ispkt);
 	if (ssh->pktin.type != SSH1_SMSG_SUCCESS
 	    && ssh->pktin.type != SSH1_SMSG_FAILURE) {
-	    bombout(("Protocol confusion"));
+	    bombout((ssh,"Protocol confusion"));
 	    crReturnV;
 	} else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
 	    c_write_str(ssh, "Server refused to allocate pty\r\n");
@@ -3156,15 +3199,17 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	} while (!ispkt);
 	if (ssh->pktin.type != SSH1_SMSG_SUCCESS
 	    && ssh->pktin.type != SSH1_SMSG_FAILURE) {
-	    bombout(("Protocol confusion"));
+	    bombout((ssh,"Protocol confusion"));
 	    crReturnV;
 	} else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
 	    c_write_str(ssh, "Server refused to compress\r\n");
 	}
 	logevent("Started compression");
 	ssh->v1_compressing = TRUE;
-	zlib_compress_init();
-	zlib_decompress_init();
+	ssh->cs_comp_ctx = zlib_compress_init();
+	logevent("Initialised zlib (RFC1950) compression");
+	ssh->sc_comp_ctx = zlib_decompress_init();
+	logevent("Initialised zlib (RFC1950) decompression");
     }
 
     /*
@@ -3194,7 +3239,8 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
     if (ssh->eof_needed)
 	ssh_special(ssh, TS_EOF);
 
-    ldisc_send(NULL, 0, 0);	       /* cause ldisc to notice changes */
+    if (ssh->ldisc)
+	ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
     ssh->send_ok = 1;
     ssh->channels = newtree234(ssh_channelcmp);
     while (1) {
@@ -3206,7 +3252,7 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		int bufsize =
 		    from_backend(ssh->frontend,
 				 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
-				 ssh->pktin.body + 4, len);
+				 (char *)(ssh->pktin.body) + 4, len);
 		if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
 		    ssh->v1_stdout_throttling = 1;
 		    ssh1_throttle(ssh, +1);
@@ -3230,7 +3276,8 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		    c = smalloc(sizeof(struct ssh_channel));
 		    c->ssh = ssh;
 
-		    if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
+		    if (x11_init(&c->u.x11.s, cfg.x11_display, c,
+				 ssh->x11auth, NULL, -1) != NULL) {
 			logevent("opening X11 forward connection failed");
 			sfree(c);
 			send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
@@ -3286,7 +3333,8 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		c->ssh = ssh;
 
 		hostsize = GET_32BIT(ssh->pktin.body+4);
-		for(h = host, p = ssh->pktin.body+8; hostsize != 0; hostsize--) {
+		for (h = host, p = (char *)(ssh->pktin.body+8);
+		     hostsize != 0; hostsize--) {
 		    if (h+1 < host+sizeof(host))
 			*h++ = *p;
 		    p++;
@@ -3356,7 +3404,6 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 
 	    } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
 		unsigned int remoteid = GET_32BIT(ssh->pktin.body);
-		unsigned int localid = GET_32BIT(ssh->pktin.body+4);
 		struct ssh_channel *c;
 
 		c = find234(ssh->channels, &remoteid, ssh_channelfind);
@@ -3403,7 +3450,7 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 			sfree(c);
 		    }
 		} else {
-		    bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
+		    bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n",
 			     ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
 			     "_CONFIRMATION", c ? "half-open" : "nonexistent",
 			     i));
@@ -3419,10 +3466,10 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		    int bufsize;
 		    switch (c->type) {
 		      case CHAN_X11:
-			bufsize = x11_send(c->u.x11.s, p, len);
+			bufsize = x11_send(c->u.x11.s, (char *)p, len);
 			break;
 		      case CHAN_SOCKDATA:
-			bufsize = pfd_send(c->u.pfd.s, p, len);
+			bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
 			break;
 		      case CHAN_AGENT:
 			/* Data for an agent message. Buffer it. */
@@ -3505,7 +3552,7 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
                 ssh->state = SSH_STATE_CLOSED;
                 crReturnV;
 	    } else {
-		bombout(("Strange packet received: type %d", ssh->pktin.type));
+		bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
 		crReturnV;
 	    }
 	} else {
@@ -3527,7 +3574,10 @@ static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
  */
 static int in_commasep_string(char *needle, char *haystack, int haylen)
 {
-    int needlen = strlen(needle);
+    int needlen;
+    if (!needle || !haystack)	       /* protect against null pointers */
+	return 0;
+    needlen = strlen(needle);
     while (1) {
 	/*
 	 * Is it at the start of the string?
@@ -3553,8 +3603,9 @@ static int in_commasep_string(char *needle, char *haystack, int haylen)
 /*
  * SSH2 key creation method.
  */
-static void ssh2_mkkey(Ssh ssh, Bignum K, char *H, char *sessid, char chr,
-		       char *keyspace)
+static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
+		       unsigned char *sessid, char chr,
+		       unsigned char *keyspace)
 {
     SHA_State s;
     /* First 20 bytes. */
@@ -3762,7 +3813,8 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 
     if (!ispkt)
 	crWaitUntil(ispkt);
-    sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
+    if (ssh->pktin.length > 5)
+	sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
 
     /*
      * Now examine the other side's KEXINIT to see what we're up
@@ -3773,7 +3825,7 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	int i, j, len;
 
 	if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
-	    bombout(("expected key exchange packet from server"));
+	    bombout((ssh,"expected key exchange packet from server"));
 	    crReturn(0);
 	}
 	ssh->kex = NULL;
@@ -3818,12 +3870,13 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	    }
 	    if (s->cscipher_tobe) {
 		if (s->warn)
-		    askcipher(s->cscipher_tobe->name, 1);
+		    askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
 		break;
 	    }
 	}
 	if (!s->cscipher_tobe) {
-	    bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
+	    bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)",
+		     str ? str : "(null)"));
 	    crReturn(0);
 	}
 
@@ -3843,12 +3896,13 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	    }
 	    if (s->sccipher_tobe) {
 		if (s->warn)
-		    askcipher(s->sccipher_tobe->name, 2);
+		    askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
 		break;
 	    }
 	}
 	if (!s->sccipher_tobe) {
-	    bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
+	    bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)",
+		     str ? str : "(null)"));
 	    crReturn(0);
 	}
 
@@ -3921,17 +3975,17 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 
 	crWaitUntil(ispkt);
 	if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
-	    bombout(("expected key exchange group packet from server"));
+	    bombout((ssh,"expected key exchange group packet from server"));
 	    crReturn(0);
 	}
 	s->p = ssh2_pkt_getmp(ssh);
 	s->g = ssh2_pkt_getmp(ssh);
-	dh_setup_group(s->p, s->g);
+	ssh->kex_ctx = dh_setup_group(s->p, s->g);
 	s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
 	s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
     } else {
 	ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
-	dh_setup_group1();
+	ssh->kex_ctx = dh_setup_group1();
 	s->kex_init_value = SSH2_MSG_KEXDH_INIT;
 	s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
     }
@@ -3940,21 +3994,21 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
     /*
      * Now generate and send e for Diffie-Hellman.
      */
-    s->e = dh_create_e(s->nbits * 2);
+    s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
     ssh2_pkt_init(ssh, s->kex_init_value);
     ssh2_pkt_addmp(ssh, s->e);
     ssh2_pkt_send(ssh);
 
     crWaitUntil(ispkt);
     if (ssh->pktin.type != s->kex_reply_value) {
-	bombout(("expected key exchange reply packet from server"));
+	bombout((ssh,"expected key exchange reply packet from server"));
 	crReturn(0);
     }
     ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
     s->f = ssh2_pkt_getmp(ssh);
     ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
 
-    s->K = dh_find_K(s->f);
+    s->K = dh_find_K(ssh->kex_ctx, s->f);
 
     sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
     if (ssh->kex == &ssh_diffiehellman_gex) {
@@ -3967,7 +4021,7 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
     sha_mpint(&ssh->exhash, s->K);
     SHA_Final(&ssh->exhash, s->exchange_hash);
 
-    dh_cleanup();
+    dh_cleanup(ssh->kex_ctx);
 
 #if 0
     debug(("Exchange hash is:\n"));
@@ -3977,8 +4031,8 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
     s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
     if (!s->hkey ||
 	!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
-				 s->exchange_hash, 20)) {
-	bombout(("Server's host key did not match the signature supplied"));
+				 (char *)s->exchange_hash, 20)) {
+	bombout((ssh,"Server's host key did not match the signature supplied"));
 	crReturn(0);
     }
 
@@ -3988,7 +4042,8 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
      */
     s->keystr = ssh->hostkey->fmtkey(s->hkey);
     s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
-    verify_ssh_host_key(ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
+    verify_ssh_host_key(ssh->frontend,
+			ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
 			s->keystr, s->fingerprint);
     if (s->first_kex) {		       /* don't bother logging this in rekeys */
 	logevent("Host key fingerprint is:");
@@ -4009,21 +4064,43 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
      */
     crWaitUntil(ispkt);
     if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
-	bombout(("expected new-keys packet from server"));
+	bombout((ssh,"expected new-keys packet from server"));
 	crReturn(0);
     }
 
     /*
      * Create and initialise session keys.
      */
+    if (ssh->cs_cipher_ctx)
+	ssh->cscipher->free_context(ssh->cs_cipher_ctx);
     ssh->cscipher = s->cscipher_tobe;
+    ssh->cs_cipher_ctx = ssh->cscipher->make_context();
+
+    if (ssh->sc_cipher_ctx)
+	ssh->sccipher->free_context(ssh->sc_cipher_ctx);
     ssh->sccipher = s->sccipher_tobe;
+    ssh->sc_cipher_ctx = ssh->sccipher->make_context();
+
+    if (ssh->cs_mac_ctx)
+	ssh->csmac->free_context(ssh->cs_mac_ctx);
     ssh->csmac = s->csmac_tobe;
+    ssh->cs_mac_ctx = ssh->csmac->make_context();
+
+    if (ssh->sc_mac_ctx)
+	ssh->scmac->free_context(ssh->sc_mac_ctx);
     ssh->scmac = s->scmac_tobe;
+    ssh->sc_mac_ctx = ssh->scmac->make_context();
+
+    if (ssh->cs_comp_ctx)
+	ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
     ssh->cscomp = s->cscomp_tobe;
+    ssh->cs_comp_ctx = ssh->cscomp->compress_init();
+
+    if (ssh->sc_comp_ctx)
+	ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
     ssh->sccomp = s->sccomp_tobe;
-    ssh->cscomp->compress_init();
-    ssh->sccomp->decompress_init();
+    ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
+
     /*
      * Set IVs after keys. Here we use the exchange hash from the
      * _first_ key exchange.
@@ -4034,18 +4111,28 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	    memcpy(ssh->v2_session_id, s->exchange_hash,
 		   sizeof(s->exchange_hash));
 	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
-	ssh->cscipher->setcskey(keyspace);
+	ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
 	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
-	ssh->sccipher->setsckey(keyspace);
+	ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
 	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
-	ssh->cscipher->setcsiv(keyspace);
+	ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
 	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
-	ssh->sccipher->setsciv(keyspace);
+	ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
 	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
-	ssh->csmac->setcskey(keyspace);
+	ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
 	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
-	ssh->scmac->setsckey(keyspace);
+	ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
     }
+    logeventf(ssh, "Initialised %.200s client->server encryption",
+	      ssh->cscipher->text_name);
+    logeventf(ssh, "Initialised %.200s server->client encryption",
+	      ssh->sccipher->text_name);
+    if (ssh->cscomp->text_name)
+	logeventf(ssh, "Initialised %s compression",
+		  ssh->cscomp->text_name);
+    if (ssh->sccomp->text_name)
+	logeventf(ssh, "Initialised %s decompression",
+		  ssh->sccomp->text_name);
 
     /*
      * If this is the first key exchange phase, we must pass the
@@ -4192,7 +4279,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
     ssh2_pkt_send(ssh);
     crWaitUntilV(ispkt);
     if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
-	bombout(("Server refused user authentication protocol"));
+	bombout((ssh,"Server refused user authentication protocol"));
 	crReturnV;
     }
 
@@ -4255,16 +4342,17 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		} while (ret == 0);
 		if (ret < 0)
 		    cleanup_exit(0);
+		c_write_str(ssh, "\r\n");
 	    }
-	    c_write_str(ssh, "\r\n");
 	    s->username[strcspn(s->username, "\n\r")] = '\0';
 	} else {
-	    char stuff[200];
+	    char *stuff;
 	    strncpy(s->username, cfg.username, sizeof(s->username));
 	    s->username[sizeof(s->username)-1] = '\0';
 	    if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
-		sprintf(stuff, "Using username \"%s\".\r\n", s->username);
+		stuff = dupprintf("Using username \"%s\".\r\n", s->username);
 		c_write_str(ssh, stuff);
+		sfree(stuff);
 	    }
 	}
 	s->got_username = TRUE;
@@ -4292,19 +4380,21 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	/* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
 	if (*cfg.keyfile) {
 	    int keytype;
-	    logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
+	    logeventf(ssh, "Reading private key file \"%.150s\"", cfg.keyfile);
 	    keytype = key_type(cfg.keyfile);
 	    if (keytype == SSH_KEYTYPE_SSH2) {
 		s->publickey_blob =
 		    ssh2_userkey_loadpub(cfg.keyfile, NULL,
 					 &s->publickey_bloblen);
 	    } else {
-		char msgbuf[256];
-		logeventf("Unable to use this key file (%s)",
-			key_type_to_str(keytype));
-		sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
-			cfg.keyfile, key_type_to_str(keytype));
+		char *msgbuf;
+		logeventf(ssh, "Unable to use this key file (%s)",
+			  key_type_to_str(keytype));
+		msgbuf = dupprintf("Unable to use key file \"%.150s\""
+				   " (%s)\r\n", cfg.keyfile,
+				   key_type_to_str(keytype));
 		c_write_str(ssh, msgbuf);
+		sfree(msgbuf);
 		s->publickey_blob = NULL;
 	    }
 	} else
@@ -4352,7 +4442,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		if (!s->gotit)
 		    s->curr_prompt = 0;
 	    } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
-		bombout(("Strange packet received during authentication: type %d",
+		bombout((ssh,"Strange packet received during authentication: type %d",
 			 ssh->pktin.type));
 		crReturnV;
 	    }
@@ -4479,13 +4569,13 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 			    logevent("This key matches configured key file");
 			    s->tried_pubkey_config = 1;
 			}
-			s->pkblob = s->p;
+			s->pkblob = (char *)s->p;
 			s->p += s->pklen;
 			s->alglen = GET_32BIT(s->pkblob);
 			s->alg = s->pkblob + 4;
 			s->commentlen = GET_32BIT(s->p);
 			s->p += 4;
-			s->commentp = s->p;
+			s->commentp = (char *)s->p;
 			s->p += s->commentlen;
 			ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
 			ssh2_pkt_addstring(ssh, s->username);
@@ -4591,8 +4681,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		 * First, offer the public blob to see if the server is
 		 * willing to accept it.
 		 */
-		pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
-						&pub_blob_len);
+		pub_blob =
+		    (unsigned char *)ssh2_userkey_loadpub(cfg.keyfile,
+							  &algorithm,
+							  &pub_blob_len);
 		if (pub_blob) {
 		    ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
 		    ssh2_pkt_addstring(ssh, s->username);
@@ -4601,7 +4693,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		    ssh2_pkt_addbool(ssh, FALSE);	/* no signature included */
 		    ssh2_pkt_addstring(ssh, algorithm);
 		    ssh2_pkt_addstring_start(ssh);
-		    ssh2_pkt_addstring_data(ssh, pub_blob, pub_blob_len);
+		    ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
+					    pub_blob_len);
 		    ssh2_pkt_send(ssh);
 		    logevent("Offered public key");	/* FIXME */
 
@@ -4741,7 +4834,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 			ssh2_pkt_addstring(ssh, "en");	/* language tag */
 			ssh2_pkt_send(ssh);
 			logevent("Unable to authenticate");
-			connection_fatal("Unable to authenticate");
+			connection_fatal(ssh->frontend,
+					 "Unable to authenticate");
 			ssh->state = SSH_STATE_CLOSED;
 			crReturnV;
 		    }
@@ -4801,7 +4895,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		    ssh2_pkt_addstring(ssh, key->alg->name);
 		    pkblob = key->alg->public_blob(key->data, &pkblob_len);
 		    ssh2_pkt_addstring_start(ssh);
-		    ssh2_pkt_addstring_data(ssh, pkblob, pkblob_len);
+		    ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
 
 		    /*
 		     * The data to be signed is:
@@ -4817,7 +4911,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		    memcpy(sigdata + 4, ssh->v2_session_id, 20);
 		    memcpy(sigdata + 24, ssh->pktout.data + 5,
 			   ssh->pktout.length - 5);
-		    sigblob = key->alg->sign(key->data, sigdata,
+		    sigblob = key->alg->sign(key->data, (char *)sigdata,
 					     sigdata_len, &sigblob_len);
 		    ssh2_add_sigblob(ssh, pkblob, pkblob_len,
 				     sigblob, sigblob_len);
@@ -4849,6 +4943,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		ssh2_pkt_addstring(ssh, "password");
 		ssh2_pkt_addbool(ssh, FALSE);
 		ssh2_pkt_addstring(ssh, s->password);
+		memset(s->password, 0, sizeof(s->password));
 		ssh2_pkt_defer(ssh);
 		/*
 		 * We'll include a string that's an exact multiple of the
@@ -4872,7 +4967,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 			 * bytes we should adjust our string length
 			 * by.
 			 */
-			stringlen -= ssh->cscomp->disable_compression();
+			stringlen -= 
+			    ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
 		    }
 		    ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
 		    ssh2_pkt_addstring_start(ssh);
@@ -4948,12 +5044,12 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
     ssh2_pkt_send(ssh);
     crWaitUntilV(ispkt);
     if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
-	bombout(("Server refused to open a session"));
+	bombout((ssh,"Server refused to open a session"));
 	crReturnV;
 	/* FIXME: error data comes back in FAILURE packet */
     }
     if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
-	bombout(("Server's channel confirmation cited wrong channel"));
+	bombout((ssh,"Server's channel confirmation cited wrong channel"));
 	crReturnV;
     }
     ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
@@ -4971,7 +5067,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
     if (cfg.x11_forward) {
 	char proto[20], data[64];
 	logevent("Requesting X11 forwarding");
-	x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
+	ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
+				       data, sizeof(data), cfg.x11_auth);
+        x11_get_real_auth(ssh->x11auth, cfg.x11_display);
 	ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
 	ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
 	ssh2_pkt_addstring(ssh, "x11-req");
@@ -4979,7 +5077,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	ssh2_pkt_addbool(ssh, 0);	       /* many connections */
 	ssh2_pkt_addstring(ssh, proto);
 	ssh2_pkt_addstring(ssh, data);
-	ssh2_pkt_adduint32(ssh, 0);	       /* screen number */
+	ssh2_pkt_adduint32(ssh, x11_get_screen_number(cfg.x11_display));
 	ssh2_pkt_send(ssh);
 
 	do {
@@ -4996,7 +5094,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 
 	if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
 	    if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
-		bombout(("Unexpected response to X11 forwarding request:"
+		bombout((ssh,"Unexpected response to X11 forwarding request:"
 			 " packet type %d", ssh->pktin.type));
 		crReturnV;
 	    }
@@ -5014,71 +5112,81 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	char type;
 	int n;
 	int sport,dport,sserv,dserv;
-	char sports[256], dports[256], host[256];
-	char buf[1024];
-	struct servent *se;
+	char sports[256], dports[256], saddr[256], host[256];
 
 	ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
         /* Add port forwardings. */
 	ssh->portfwd_strptr = cfg.portfwd;
 	while (*ssh->portfwd_strptr) {
 	    type = *ssh->portfwd_strptr++;
+	    saddr[0] = '\0';
 	    n = 0;
-	    while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
-		sports[n++] = *ssh->portfwd_strptr++;
+	    while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
+		if (*ssh->portfwd_strptr == ':') {
+		    /*
+		     * We've seen a colon in the middle of the
+		     * source port number. This means that
+		     * everything we've seen until now is the
+		     * source _address_, so we'll move it into
+		     * saddr and start sports from the beginning
+		     * again.
+		     */
+		    ssh->portfwd_strptr++;
+		    sports[n] = '\0';
+		    strcpy(saddr, sports);
+		    n = 0;
+		}
+		if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
+	    }
 	    sports[n] = 0;
 	    if (*ssh->portfwd_strptr == '\t')
 		ssh->portfwd_strptr++;
 	    n = 0;
-	    while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
-		host[n++] = *ssh->portfwd_strptr++;
+	    while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
+		if (n < 255) host[n++] = *ssh->portfwd_strptr++;
+	    }
 	    host[n] = 0;
 	    if (*ssh->portfwd_strptr == ':')
 		ssh->portfwd_strptr++;
 	    n = 0;
-	    while (*ssh->portfwd_strptr)
-		dports[n++] = *ssh->portfwd_strptr++;
+	    while (*ssh->portfwd_strptr) {
+		if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
+	    }
 	    dports[n] = 0;
 	    ssh->portfwd_strptr++;
 	    dport = atoi(dports);
 	    dserv = 0;
 	    if (dport == 0) {
 		dserv = 1;
-		se = getservbyname(dports, NULL);
-		if (se != NULL) {
-		    dport = ntohs(se->s_port);
-		} else {
-		    sprintf(buf,
-			    "Service lookup failed for destination port \"%s\"",
-			    dports);
-		    logevent(buf);
+		dport = net_service_lookup(dports);
+		if (!dport) {
+		    logeventf(ssh, "Service lookup failed for destination"
+			      " port \"%s\"", dports);
 		}
 	    }
 	    sport = atoi(sports);
 	    sserv = 0;
 	    if (sport == 0) {
 		sserv = 1;
-		se = getservbyname(sports, NULL);
-		if (se != NULL) {
-		    sport = ntohs(se->s_port);
-		} else {
-		    sprintf(buf,
-			    "Service lookup failed for source port \"%s\"",
-			    sports);
-		    logevent(buf);
+		sport = net_service_lookup(sports);
+		if (!sport) {
+		    logeventf(ssh, "Service lookup failed for source"
+			      " port \"%s\"", sports);
 		}
 	    }
 	    if (sport && dport) {
 		if (type == 'L') {
-		    pfd_addforward(host, dport, sport);
-		    sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
-			    " %s:%.*s%.*s%d%.*s",
-			    sserv ? strlen(sports) : 0, sports,
-			    sserv, "(", sport, sserv, ")",
-			    host,
-			    dserv ? strlen(dports) : 0, dports,
-			    dserv, "(", dport, dserv, ")");
-		    logevent(buf);
+		    pfd_addforward(host, dport, *saddr ? saddr : NULL,
+				   sport, ssh);
+		    logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
+			      " forwarding to %s:%.*s%.*s%d%.*s",
+			      (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
+			      (int)(*saddr?1:0), ":",
+			      (int)(sserv ? strlen(sports) : 0), sports,
+			      sserv, "(", sport, sserv, ")",
+			      host,
+			      (int)(dserv ? strlen(dports) : 0), dports,
+			      dserv, "(", dport, dserv, ")");
 		} else {
 		    struct ssh_rportfwd *pf;
 		    pf = smalloc(sizeof(*pf));
@@ -5086,23 +5194,26 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		    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);
+			logeventf(ssh, "Duplicate remote port forwarding"
+				  " to %s:%d", host, dport);
 			sfree(pf);
 		    } else {
-			sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
-				" forward to %s:%.*s%.*s%d%.*s",
-			    sserv ? strlen(sports) : 0, sports,
-			    sserv, "(", sport, sserv, ")",
-			    host,
-			    dserv ? strlen(dports) : 0, dports,
-			    dserv, "(", dport, dserv, ")");
-			logevent(buf);
+			logeventf(ssh, "Requesting remote port "
+				  "%.*s%.*s%.*s%.*s%d%.*s"
+				  " forward to %s:%.*s%.*s%d%.*s",
+				  (int)(*saddr?strlen(saddr):0),
+				  *saddr?saddr:NULL,
+				  (int)(*saddr?1:0), ":",
+				  (int)(sserv ? strlen(sports) : 0), sports,
+				  sserv, "(", sport, sserv, ")",
+				  host,
+				  (int)(dserv ? strlen(dports) : 0), dports,
+				  dserv, "(", dport, dserv, ")");
 			ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
 			ssh2_pkt_addstring(ssh, "tcpip-forward");
 			ssh2_pkt_addbool(ssh, 1);/* want reply */
+			if (*saddr)
+			    ssh2_pkt_addstring(ssh, saddr);
 			if (cfg.rport_acceptall)
 			    ssh2_pkt_addstring(ssh, "0.0.0.0");
 			else
@@ -5124,7 +5235,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 
 			if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
 			    if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
-				bombout(("Unexpected response to port "
+				bombout((ssh,"Unexpected response to port "
 					 "forwarding request: packet type %d",
 					 ssh->pktin.type));
 				crReturnV;
@@ -5164,7 +5275,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 
 	if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
 	    if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
-		bombout(("Unexpected response to agent forwarding request:"
+		bombout((ssh,"Unexpected response to agent forwarding request:"
 			 " packet type %d", ssh->pktin.type));
 		crReturnV;
 	    }
@@ -5207,7 +5318,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 
 	if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
 	    if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
-		bombout(("Unexpected response to pty request:"
+		bombout((ssh,"Unexpected response to pty request:"
 			 " packet type %d", ssh->pktin.type));
 		crReturnV;
 	    }
@@ -5265,7 +5376,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	} while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
 	if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
 	    if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
-		bombout(("Unexpected response to shell/command request:"
+		bombout((ssh,"Unexpected response to shell/command request:"
 			 " packet type %d", ssh->pktin.type));
 		crReturnV;
 	    }
@@ -5280,7 +5391,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		ssh->fallback_cmd = TRUE;
 		continue;
 	    }
-	    bombout(("Server refused to start a shell/command"));
+	    bombout((ssh,"Server refused to start a shell/command"));
 	    crReturnV;
 	} else {
 	    logevent("Started a shell/command");
@@ -5297,7 +5408,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
     /*
      * Transfer data!
      */
-    ldisc_send(NULL, 0, 0);	       /* cause ldisc to notice changes */
+    if (ssh->ldisc)
+	ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
     ssh->send_ok = 1;
     while (1) {
 	crReturnV;
@@ -5416,7 +5528,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 
 		c = find234(ssh->channels, &i, ssh_channelfind);
 		if (!c || ((int)c->remoteid) == -1) {
-		    bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
+		    bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n",
 			     c ? "half-open" : "nonexistent", i));
 		}
 		/* Do pre-close processing on the channel. */
@@ -5477,8 +5589,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		unsigned i = ssh2_pkt_getuint32(ssh);
 		struct ssh_channel *c;
 		c = find234(ssh->channels, &i, ssh_channelfind);
-		if (!c)
-		    continue;	       /* nonexistent channel */
+		if (!c || c->closes)
+		    continue;	       /* nonexistent or closing channel */
 		c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
 		s->try_send = TRUE;
 	    } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
@@ -5602,6 +5714,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	    } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
 		char *type;
 		int typelen;
+		char *peeraddr;
+		int peeraddrlen;
+		int port;
 		char *error = NULL;
 		struct ssh_channel *c;
 		unsigned remid, winsize, pktsize;
@@ -5612,16 +5727,24 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		remid = ssh2_pkt_getuint32(ssh);
 		winsize = ssh2_pkt_getuint32(ssh);
 		pktsize = ssh2_pkt_getuint32(ssh);
+		ssh2_pkt_getstring(ssh, &peeraddr, &peeraddrlen);
+		port = ssh2_pkt_getuint32(ssh);
 
 		if (typelen == 3 && !memcmp(type, "x11", 3)) {
+		    char *addrstr = smalloc(peeraddrlen+1);
+		    memcpy(addrstr, peeraddr, peeraddrlen);
+		    peeraddr[peeraddrlen] = '\0';
+
 		    if (!ssh->X11_fwd_enabled)
 			error = "X11 forwarding is not enabled";
-		    else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
-			     NULL) {
+		    else if (x11_init(&c->u.x11.s, cfg.x11_display, c,
+				      ssh->x11auth, addrstr, port) != NULL) {
 			error = "Unable to open an X11 connection";
 		    } else {
 			c->type = CHAN_X11;
 		    }
+
+		    sfree(addrstr);
 		} else if (typelen == 15 &&
 			   !memcmp(type, "forwarded-tcpip", 15)) {
 		    struct ssh_rportfwd pf, *realpf;
@@ -5635,13 +5758,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		    } 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);
+			logeventf(ssh, "Received remote port open request"
+				  " for %s:%d", realpf->dhost, realpf->dport);
 			if (e != NULL) {
-			    sprintf(buf, "Port open failed: %s", e);
-			    logevent(buf);
+			    logeventf(ssh, "Port open failed: %s", e);
 			    error = "Port open failed";
 			} else {
 			    logevent("Forwarded port opened successfully");
@@ -5685,14 +5805,14 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 		    ssh2_pkt_send(ssh);
 		}
 	    } else {
-		bombout(("Strange packet received: type %d", ssh->pktin.type));
+		bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
 		crReturnV;
 	    }
 	} else {
 	    /*
 	     * We have spare data. Add it to the channel buffer.
 	     */
-	    ssh2_add_channel_data(ssh->mainchan, in, inlen);
+	    ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
 	    s->try_send = TRUE;
 	}
 	if (s->try_send) {
@@ -5702,7 +5822,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
 	     * Try to send data on all channels if we can.
 	     */
 	    for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
-		int bufsize = ssh2_try_send(c);
+		int bufsize;
+		if (c->closes)
+		    continue;	       /* don't send on closing channels */
+		bufsize = ssh2_try_send(c);
 		if (bufsize == 0) {
 		    switch (c->type) {
 		      case CHAN_MAINSESSION:
@@ -5752,18 +5875,28 @@ static char *ssh_init(void *frontend_handle, void **backend_handle,
     ssh = smalloc(sizeof(*ssh));
     ssh->s = NULL;
     ssh->cipher = NULL;
+    ssh->v1_cipher_ctx = NULL;
+    ssh->crcda_ctx = NULL;
     ssh->cscipher = NULL;
+    ssh->cs_cipher_ctx = NULL;
     ssh->sccipher = NULL;
+    ssh->sc_cipher_ctx = NULL;
     ssh->csmac = NULL;
+    ssh->cs_mac_ctx = NULL;
     ssh->scmac = NULL;
+    ssh->sc_mac_ctx = NULL;
     ssh->cscomp = NULL;
+    ssh->cs_comp_ctx = NULL;
     ssh->sccomp = NULL;
+    ssh->sc_comp_ctx = NULL;
     ssh->kex = NULL;
     ssh->hostkey = NULL;
     ssh->exitcode = -1;
     ssh->state = SSH_STATE_PREPACKET;
     ssh->size_needed = FALSE;
     ssh->eof_needed = FALSE;
+    ssh->ldisc = NULL;
+    ssh->logctx = NULL;
     {
 	static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
 	ssh->pktin = ssh->pktout = empty;
@@ -5773,6 +5906,8 @@ static char *ssh_init(void *frontend_handle, void **backend_handle,
     ssh->deferred_size = 0;
     ssh->fallback_cmd = 0;
     ssh->pkt_ctx = 0;
+    ssh->x11auth = NULL;
+    ssh->v1_compressing = FALSE;
     ssh->v2_outgoing_sequence = 0;
     ssh->ssh1_rdpkt_crstate = 0;
     ssh->ssh2_rdpkt_crstate = 0;
@@ -5786,6 +5921,9 @@ static char *ssh_init(void *frontend_handle, void **backend_handle,
     ssh->do_ssh1_login_state = NULL;
     ssh->do_ssh2_transport_state = NULL;
     ssh->do_ssh2_authconn_state = NULL;
+    ssh->mainchan = NULL;
+    ssh->throttled_all = 0;
+    ssh->v1_stdout_throttling = 0;
 
     *backend_handle = ssh;
 
@@ -5805,6 +5943,8 @@ static char *ssh_init(void *frontend_handle, void **backend_handle,
     ssh->overall_bufsize = 0;
     ssh->fallback_cmd = 0;
 
+    ssh->protocol = NULL;
+
     p = connect_to_host(ssh, host, port, realhost, nodelay);
     if (p != NULL)
 	return p;
@@ -5822,7 +5962,7 @@ static int ssh_send(void *handle, char *buf, int len)
     if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
 	return 0;
 
-    ssh->protocol(ssh, buf, len, 0);
+    ssh->protocol(ssh, (unsigned char *)buf, len, 0);
 
     return ssh_sendbuffer(ssh);
 }
@@ -5879,8 +6019,6 @@ static void ssh_size(void *handle, int width, int height)
 	break;
       case SSH_STATE_SESSION:
 	if (!cfg.nopty) {
-	    if (!term)
-		return;
 	    if (ssh->version == 1) {
 		send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
 			    PKT_INT, ssh->term_height,
@@ -5968,7 +6106,7 @@ void *new_sock_channel(void *handle, Socket s)
  * This is called when stdout/stderr (the entity to which
  * from_backend sends data) manages to clear some backlog.
  */
-void ssh_unthrottle(void *handle, int bufsize)
+static void ssh_unthrottle(void *handle, int bufsize)
 {
     Ssh ssh = (Ssh) handle;
     if (ssh->version == 1) {
@@ -5982,15 +6120,12 @@ void ssh_unthrottle(void *handle, int bufsize)
     }
 }
 
-void ssh_send_port_open(void *handle, void *channel, char *hostname,
-			int port, char *org)
+void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
 {
-    Ssh ssh = (Ssh) handle;
     struct ssh_channel *c = (struct ssh_channel *)channel;
-    char buf[1024];
+    Ssh ssh = c->ssh;
 
-    sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
-    logevent(buf);
+    logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
 
     if (ssh->version == 1) {
 	send_packet(ssh, SSH1_MSG_PORT_OPEN,
@@ -6043,6 +6178,18 @@ static int ssh_ldisc(void *handle, int option)
     return FALSE;
 }
 
+static void ssh_provide_ldisc(void *handle, void *ldisc)
+{
+    Ssh ssh = (Ssh) handle;
+    ssh->ldisc = ldisc;
+}
+
+static void ssh_provide_logctx(void *handle, void *logctx)
+{
+    Ssh ssh = (Ssh) handle;
+    ssh->logctx = logctx;
+}
+
 static int ssh_return_exitcode(void *handle)
 {
     Ssh ssh = (Ssh) handle;
@@ -6070,6 +6217,8 @@ Backend ssh_backend = {
     ssh_return_exitcode,
     ssh_sendok,
     ssh_ldisc,
+    ssh_provide_ldisc,
+    ssh_provide_logctx,
     ssh_unthrottle,
     22
 };