X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/178c387223509d6f1c9887acfcee93df9f90d690..fae1a71b5a2fd1b2983be523350c3dae4b5e6903:/ssh.c

diff --git a/ssh.c b/ssh.c
index 6fe865b7..64a069ef 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1,7 +1,13 @@
+/*
+ * SSH backend.
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <assert.h>
+#include <limits.h>
+#include <signal.h>
 
 #include "putty.h"
 #include "tree234.h"
@@ -77,6 +83,9 @@
 #define SSH2_MSG_KEX_DH_GEX_GROUP                 31	/* 0x1f */
 #define SSH2_MSG_KEX_DH_GEX_INIT                  32	/* 0x20 */
 #define SSH2_MSG_KEX_DH_GEX_REPLY                 33	/* 0x21 */
+#define SSH2_MSG_KEXRSA_PUBKEY                    30    /* 0x1e */
+#define SSH2_MSG_KEXRSA_SECRET                    31    /* 0x1f */
+#define SSH2_MSG_KEXRSA_DONE                      32    /* 0x20 */
 #define SSH2_MSG_USERAUTH_REQUEST                 50	/* 0x32 */
 #define SSH2_MSG_USERAUTH_FAILURE                 51	/* 0x33 */
 #define SSH2_MSG_USERAUTH_SUCCESS                 52	/* 0x34 */
@@ -106,6 +115,7 @@
  */
 #define SSH2_PKTCTX_DHGROUP          0x0001
 #define SSH2_PKTCTX_DHGEX            0x0002
+#define SSH2_PKTCTX_RSAKEX           0x0004
 #define SSH2_PKTCTX_KEX_MASK         0x000F
 #define SSH2_PKTCTX_PUBLICKEY        0x0010
 #define SSH2_PKTCTX_PASSWORD         0x0020
@@ -130,21 +140,21 @@
 
 static const char *const ssh2_disconnect_reasons[] = {
     NULL,
-    "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
-    "SSH_DISCONNECT_PROTOCOL_ERROR",
-    "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
-    "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
-    "SSH_DISCONNECT_MAC_ERROR",
-    "SSH_DISCONNECT_COMPRESSION_ERROR",
-    "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
-    "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
-    "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
-    "SSH_DISCONNECT_CONNECTION_LOST",
-    "SSH_DISCONNECT_BY_APPLICATION",
-    "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
-    "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
-    "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
-    "SSH_DISCONNECT_ILLEGAL_USER_NAME",
+    "host not allowed to connect",
+    "protocol error",
+    "key exchange failed",
+    "host authentication failed",
+    "MAC error",
+    "compression error",
+    "service not available",
+    "protocol version not supported",
+    "host key not verifiable",
+    "connection lost",
+    "by application",
+    "too many connections",
+    "auth cancelled by user",
+    "no more auth methods available",
+    "illegal user name",
 };
 
 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED     1	/* 0x1 */
@@ -333,6 +343,9 @@ static char *ssh2_pkt_type(int pkt_ctx, int type)
     translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
     translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
     translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
+    translatec(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
+    translatec(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
+    translatec(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
     translate(SSH2_MSG_USERAUTH_REQUEST);
     translate(SSH2_MSG_USERAUTH_FAILURE);
     translate(SSH2_MSG_USERAUTH_SUCCESS);
@@ -459,13 +472,16 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 #define OUR_V2_WINSIZE 16384
 #define OUR_V2_MAXPKT 0x4000UL
 
+/* Maximum length of passwords/passphrases (arbitrary) */
+#define SSH_MAX_PASSWORD_LEN 100
+
 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
 
 const static struct ssh_mac *macs[] = {
-    &ssh_sha1, &ssh_md5
+    &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
 };
 const static struct ssh_mac *buggymacs[] = {
-    &ssh_sha1_buggy, &ssh_md5
+    &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
 };
 
 static void *ssh_comp_none_init(void)
@@ -679,7 +695,8 @@ struct ssh_tag {
     const struct plug_function_table *fn;
     /* the above field _must_ be first in the structure */
 
-    SHA_State exhash, exhashbase;
+    char *v_c, *v_s;
+    void *exhash;
 
     Socket s;
 
@@ -704,7 +721,8 @@ struct ssh_tag {
     void *cs_comp_ctx, *sc_comp_ctx;
     const struct ssh_kex *kex;
     const struct ssh_signkey *hostkey;
-    unsigned char v2_session_id[20];
+    unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
+    int v2_session_id_len;
     void *kex_ctx;
 
     char *savedhost;
@@ -719,8 +737,10 @@ struct ssh_tag {
 
     tree234 *channels;		       /* indexed by local id */
     struct ssh_channel *mainchan;      /* primary session channel */
+    int ncmode;			       /* is primary channel direct-tcpip? */
     int exitcode;
     int close_expected;
+    int clean_exit;
 
     tree234 *rportfwds, *portfwds;
 
@@ -748,13 +768,7 @@ struct ssh_tag {
      */
     int fallback_cmd;
 
-    /*
-     * Used for username and password input.
-     */
-    char *userpass_input_buffer;
-    int userpass_input_buflen;
-    int userpass_input_bufpos;
-    int userpass_input_echo;
+    bufchain banner;	/* accumulates banners during do_ssh2_authconn */
 
     int pkt_ctx;
 
@@ -1042,27 +1056,28 @@ static int alloc_channel_id(Ssh ssh)
     return low + 1 + CHANNEL_NUMBER_OFFSET;
 }
 
+static void c_write_stderr(int trusted, const char *buf, int len)
+{
+    int i;
+    for (i = 0; i < len; i++)
+	if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
+	    fputc(buf[i], stderr);
+}
+
 static void c_write(Ssh ssh, const char *buf, int len)
 {
-    if ((flags & FLAG_STDERR)) {
-	int i;
-	for (i = 0; i < len; i++)
-	    if (buf[i] != '\r')
-		fputc(buf[i], stderr);
-	return;
-    }
-    from_backend(ssh->frontend, 1, buf, len);
+    if (flags & FLAG_STDERR)
+	c_write_stderr(1, buf, len);
+    else
+	from_backend(ssh->frontend, 1, buf, len);
 }
 
 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
 {
-    int i;
-    for (i = 0; i < len; i++) {
-	if (buf[i] == '\n')
-	    c_write(ssh, "\r\n", 2);
-	else if ((buf[i] & 0x60) || (buf[i] == '\r'))
-	    c_write(ssh, buf + i, 1);
-    }
+    if (flags & FLAG_STDERR)
+	c_write_stderr(0, buf, len);
+    else
+	from_backend_untrusted(ssh->frontend, buf, len);
 }
 
 static void c_write_str(Ssh ssh, const char *buf)
@@ -1265,7 +1280,8 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
      * _Completely_ silly lengths should be stomped on before they
      * do us any more damage.
      */
-    if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
+    if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
+	st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
 	bombout(("Incoming packet was garbled on decryption"));
 	ssh_free_packet(st->pktin);
 	crStop(NULL);
@@ -1434,11 +1450,17 @@ static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
     return biglen + 4;		/* len(length+padding+type+data+CRC) */
 }
 
+static int s_write(Ssh ssh, void *data, int len)
+{
+    log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len, 0, NULL);
+    return sk_write(ssh->s, (char *)data, len);
+}
+
 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
 {
     int len, backlog, offset;
     len = s_wrpkt_prepare(ssh, pkt, &offset);
-    backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
+    backlog = s_write(ssh, pkt->data + offset, len);
     if (backlog > SSH_MAX_BACKLOG)
 	ssh_throttle_all(ssh, 1, backlog);
     ssh_free_packet(pkt);
@@ -1475,6 +1497,7 @@ static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
 
     while ((argtype = va_arg(ap, int)) != PKT_END) {
 	unsigned char *argp, argchar;
+	char *sargp;
 	unsigned long argint;
 	int arglen;
 	switch (argtype) {
@@ -1493,8 +1516,8 @@ static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
 	    ssh_pkt_adddata(pkt, argp, arglen);
 	    break;
 	  case PKT_STR:
-	    argp = va_arg(ap, unsigned char *);
-	    ssh_pkt_addstring(pkt, argp);
+	    sargp = va_arg(ap, char *);
+	    ssh_pkt_addstring(pkt, sargp);
 	    break;
 	  case PKT_BIGNUM:
 	    bn = va_arg(ap, Bignum);
@@ -1558,21 +1581,21 @@ static int ssh_versioncmp(char *a, char *b)
 
 /*
  * Utility routines for putting an SSH-protocol `string' and
- * `uint32' into a SHA state.
+ * `uint32' into a hash state.
  */
-static void sha_string(SHA_State * s, void *str, int len)
+static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
 {
     unsigned char lenblk[4];
     PUT_32BIT(lenblk, len);
-    SHA_Bytes(s, lenblk, 4);
-    SHA_Bytes(s, str, len);
+    h->bytes(s, lenblk, 4);
+    h->bytes(s, str, len);
 }
 
-static void sha_uint32(SHA_State * s, unsigned i)
+static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
 {
     unsigned char intblk[4];
     PUT_32BIT(intblk, i);
-    SHA_Bytes(s, intblk, 4);
+    h->bytes(s, intblk, 4);
 }
 
 /*
@@ -1582,7 +1605,7 @@ static void ssh_pkt_ensure(struct Packet *pkt, int length)
 {
     if (pkt->maxlen < length) {
 	unsigned char *body = pkt->body;
-	int offset = body ? pkt->data - body : 0;
+	int offset = body ? body - pkt->data : 0;
 	pkt->maxlen = length + 256;
 	pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
 	if (body) pkt->body = pkt->data + offset;
@@ -1640,7 +1663,7 @@ static void ssh_pkt_addstring(struct Packet *pkt, char *data)
 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
 {
     int len = ssh1_bignum_length(b);
-    unsigned char *data = snewn(len, char);
+    unsigned char *data = snewn(len, unsigned char);
     (void) ssh1_write_bignum(data, b);
     ssh_pkt_adddata(pkt, data, len);
     sfree(data);
@@ -1650,8 +1673,6 @@ static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
     unsigned char *p;
     int i, n = (bignum_bitcount(b) + 7) / 8;
     p = snewn(n + 1, unsigned char);
-    if (!p)
-	fatalbox("out of memory");
     p[0] = 0;
     for (i = 1; i <= n; i++)
 	p[i] = bignum_byte(b, n - i);
@@ -1694,10 +1715,10 @@ static struct Packet *ssh1_pkt_init(int pkt_type)
 static struct Packet *ssh2_pkt_init(int pkt_type)
 {
     struct Packet *pkt = ssh_new_packet();
-    pkt->length = 5;
+    pkt->length = 5; /* space for packet length + padding length */
     pkt->forcepad = 0;
     ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
-    pkt->body = pkt->data + pkt->length;
+    pkt->body = pkt->data + pkt->length; /* after packet type */
     return pkt;
 }
 
@@ -1824,7 +1845,7 @@ static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
 	return;
     }
     len = ssh2_pkt_construct(ssh, pkt);
-    backlog = sk_write(ssh->s, (char *)pkt->data, len);
+    backlog = s_write(ssh, pkt->data, len);
     if (backlog > SSH_MAX_BACKLOG)
 	ssh_throttle_all(ssh, 1, backlog);
 
@@ -1850,6 +1871,7 @@ static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
 	 * get encrypted with a known IV.
 	 */
 	struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
+	ssh2_pkt_addstring_start(ipkt);
 	ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
     }
     len = ssh2_pkt_construct(ssh, pkt);
@@ -1892,7 +1914,6 @@ static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
 	ssh2_pkt_send_noqueue(ssh, pkt);
 }
 
-#if 0 /* disused */
 /*
  * Either queue or defer a packet, depending on whether queueing is
  * set.
@@ -1904,7 +1925,6 @@ static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
     else
 	ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
 }
-#endif
 
 /*
  * Send the whole deferred data block constructed by
@@ -1922,8 +1942,7 @@ static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
 static void ssh_pkt_defersend(Ssh ssh)
 {
     int backlog;
-    backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
-		       ssh->deferred_len);
+    backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
     ssh->deferred_len = ssh->deferred_size = 0;
     sfree(ssh->deferred_send_data);
     ssh->deferred_send_data = NULL;
@@ -1939,6 +1958,74 @@ static void ssh_pkt_defersend(Ssh ssh)
 }
 
 /*
+ * Send a packet whose length needs to be disguised (typically
+ * passwords or keyboard-interactive responses).
+ */
+static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
+				       int padsize)
+{
+#if 0
+    if (0) {
+	/*
+	 * The simplest way to do this is to adjust the
+	 * variable-length padding field in the outgoing packet.
+	 * 
+	 * Currently compiled out, because some Cisco SSH servers
+	 * don't like excessively padded packets (bah, why's it
+	 * always Cisco?)
+	 */
+	pkt->forcepad = padsize;
+	ssh2_pkt_send(ssh, pkt);
+    } else
+#endif
+    {
+	/*
+	 * If we can't do that, however, an alternative approach is
+	 * to use the pkt_defer mechanism to bundle the packet
+	 * tightly together with an SSH_MSG_IGNORE such that their
+	 * combined length is a constant. So first we construct the
+	 * final form of this packet and defer its sending.
+	 */
+	ssh2_pkt_defer(ssh, pkt);
+
+	/*
+	 * Now construct an SSH_MSG_IGNORE which includes a string
+	 * that's an exact multiple of the cipher block size. (If
+	 * the cipher is NULL so that the block size is
+	 * unavailable, we don't do this trick at all, because we
+	 * gain nothing by it.)
+	 */
+	if (ssh->cscipher) {
+	    int stringlen, i;
+
+	    stringlen = (256 - ssh->deferred_len);
+	    stringlen += ssh->cscipher->blksize - 1;
+	    stringlen -= (stringlen % ssh->cscipher->blksize);
+	    if (ssh->cscomp) {
+		/*
+		 * Temporarily disable actual compression, so we
+		 * can guarantee to get this string exactly the
+		 * length we want it. The compression-disabling
+		 * routine should return an integer indicating how
+		 * many bytes we should adjust our string length
+		 * by.
+		 */
+		stringlen -=
+		    ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
+	    }
+	    pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
+	    ssh2_pkt_addstring_start(pkt);
+	    for (i = 0; i < stringlen; i++) {
+		char c = (char) random_byte();
+		ssh2_pkt_addstring_data(pkt, &c, 1);
+	    }
+	    ssh2_pkt_defer(ssh, pkt);
+	}
+	ssh_pkt_defersend(ssh);
+    }
+}
+
+/*
  * Send all queued SSH-2 packets. We send them by means of
  * ssh2_pkt_defer_noqueue(), in case they included a pair of
  * packets that needed to be lumped together.
@@ -1970,12 +2057,12 @@ void bndebug(char *string, Bignum b)
 }
 #endif
 
-static void sha_mpint(SHA_State * s, Bignum b)
+static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
 {
     unsigned char *p;
     int len;
     p = ssh2_mpint_fmt(b, &len);
-    sha_string(s, p, len);
+    hash_string(h, s, p, len);
     sfree(p);
 }
 
@@ -2155,6 +2242,13 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring)
 
     ssh->remote_bugs = 0;
 
+    /*
+     * General notes on server version strings:
+     *  - Not all servers reporting "Cisco-1.25" have all the bugs listed
+     *    here -- in particular, we've heard of one that's perfectly happy
+     *    with SSH1_MSG_IGNOREs -- but this string never seems to change,
+     *    so we can't distinguish them.
+     */
     if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
 	(ssh->cfg.sshbug_ignore1 == AUTO &&
 	 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
@@ -2244,10 +2338,13 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring)
 
     if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
 	(ssh->cfg.sshbug_rekey2 == AUTO &&
-	 (wc_match("OpenSSH_2.[0-4]*", imp) ||
+	 (wc_match("DigiSSH_2.0", imp) ||
+	  wc_match("OpenSSH_2.[0-4]*", imp) ||
 	  wc_match("OpenSSH_2.5.[0-3]*", imp) ||
 	  wc_match("Sun_SSH_1.0", imp) ||
-	  wc_match("Sun_SSH_1.0.1", imp)))) {
+	  wc_match("Sun_SSH_1.0.1", imp) ||
+	  /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
+	  wc_match("WeOnlyDo-*", imp)))) {
 	/*
 	 * These versions have the SSH-2 rekey bug.
 	 */
@@ -2293,23 +2390,20 @@ static int do_ssh_init(Ssh ssh, unsigned char c)
 
     crBegin(ssh->do_ssh_init_crstate);
 
-    /* Search for the string "SSH-" in the input. */
-    s->i = 0;
-    while (1) {
-	static const int transS[] = { 1, 2, 2, 1 };
-	static const int transH[] = { 0, 0, 3, 0 };
-	static const int transminus[] = { 0, 0, 0, -1 };
-	if (c == 'S')
-	    s->i = transS[s->i];
-	else if (c == 'H')
-	    s->i = transH[s->i];
-	else if (c == '-')
-	    s->i = transminus[s->i];
-	else
-	    s->i = 0;
-	if (s->i < 0)
-	    break;
-	crReturn(1);		       /* get another character */
+    /* Search for a line beginning with the string "SSH-" in the input. */
+    for (;;) {
+	if (c != 'S') goto no;
+	crReturn(1);
+	if (c != 'S') goto no;
+	crReturn(1);
+	if (c != 'H') goto no;
+	crReturn(1);
+	if (c != '-') goto no;
+	break;
+      no:
+	while (c != '\012')
+	    crReturn(1);
+	crReturn(1);
     }
 
     s->vstrsize = 16;
@@ -2383,15 +2477,19 @@ static int do_ssh_init(Ssh ssh, unsigned char c)
         ssh_fix_verstring(verstring);
 
         if (ssh->version == 2) {
+	    size_t len;
             /*
              * Hash our version string and their version string.
              */
-            SHA_Init(&ssh->exhashbase);
-            sha_string(&ssh->exhashbase, verstring,
-                       strcspn(verstring, "\015\012"));
-            sha_string(&ssh->exhashbase, s->vstring,
-                       strcspn(s->vstring, "\015\012"));
-
+	    len = strcspn(verstring, "\015\012");
+	    ssh->v_c = snewn(len + 1, char);
+	    memcpy(ssh->v_c, verstring, len);
+	    ssh->v_c[len] = 0;
+	    len = strcspn(s->vstring, "\015\012");
+	    ssh->v_s = snewn(len + 1, char);
+	    memcpy(ssh->v_s, s->vstring, len);
+	    ssh->v_s[len] = 0;
+	    
             /*
              * Initialise SSH-2 protocol.
              */
@@ -2408,7 +2506,7 @@ static int do_ssh_init(Ssh ssh, unsigned char c)
         }
         logeventf(ssh, "We claim version: %.*s",
                   strcspn(verstring, "\015\012"), verstring);
-	sk_write(ssh->s, verstring, strlen(verstring));
+	s_write(ssh, verstring, strlen(verstring));
         sfree(verstring);
 	if (ssh->version == 2)
 	    do_ssh2_transport(ssh, NULL, -1, NULL);
@@ -2428,7 +2526,9 @@ static int do_ssh_init(Ssh ssh, unsigned char c)
 static void ssh_process_incoming_data(Ssh ssh,
 				      unsigned char **data, int *datalen)
 {
-    struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
+    struct Packet *pktin;
+
+    pktin = ssh->s_rdpkt(ssh, data, datalen);
     if (pktin) {
 	ssh->protocol(ssh, NULL, 0, pktin);
 	ssh_free_packet(pktin);
@@ -2471,6 +2571,9 @@ static void ssh_set_frozen(Ssh ssh, int frozen)
 
 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
 {
+    /* Log raw data, if we're in that mode. */
+    log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen, 0, NULL);
+
     crBegin(ssh->ssh_gotdata_crstate);
 
     /*
@@ -2496,24 +2599,29 @@ static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
      * everything to s_rdpkt, and then pass the resulting packets
      * to the proper protocol handler.
      */
-    if (datalen == 0)
-	crReturnV;
-
-    /*
-     * Process queued data if there is any.
-     */
-    ssh_process_queued_incoming_data(ssh);
 
     while (1) {
-	while (datalen > 0) {
-	    if (ssh->frozen)
+	while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
+	    if (ssh->frozen) {
 		ssh_queue_incoming_data(ssh, &data, &datalen);
-
-	    ssh_process_incoming_data(ssh, &data, &datalen);
-
+		/* This uses up all data and cannot cause anything interesting
+		 * to happen; indeed, for anything to happen at all, we must
+		 * return, so break out. */
+		break;
+	    } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
+		/* This uses up some or all data, and may freeze the
+		 * session. */
+		ssh_process_queued_incoming_data(ssh);
+	    } else {
+		/* This uses up some or all data, and may freeze the
+		 * session. */
+		ssh_process_incoming_data(ssh, &data, &datalen);
+	    }
+	    /* FIXME this is probably EBW. */
 	    if (ssh->state == SSH_STATE_CLOSED)
 		return;
 	}
+	/* We're out of data. Go and get some more. */
 	crReturnV;
     }
     crFinishV;
@@ -2595,20 +2703,23 @@ static int ssh_closing(Plug plug, const char *error_msg, int error_code,
     Ssh ssh = (Ssh) plug;
     int need_notify = ssh_do_close(ssh, FALSE);
 
-    if (!error_msg && !ssh->close_expected) {
-        error_msg = "Server unexpectedly closed network connection";
+    if (!error_msg) {
+	if (!ssh->close_expected)
+	    error_msg = "Server unexpectedly closed network connection";
+	else
+	    error_msg = "Server closed network connection";
     }
 
+    if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
+	ssh->exitcode = 0;
+
     if (need_notify)
         notify_remote_exit(ssh->frontend);
 
-    if (error_msg) {
-	/* A socket error has occurred. */
+    if (error_msg)
 	logevent(error_msg);
+    if (!ssh->close_expected || !ssh->clean_exit)
 	connection_fatal(ssh->frontend, "%s", error_msg);
-    } else {
-        logevent("Server closed network connection");
-    }
     return 0;
 }
 
@@ -2655,8 +2766,6 @@ static const char *connect_to_host(Ssh ssh, char *host, int port,
     const char *err;
 
     ssh->savedhost = snewn(1 + strlen(host), char);
-    if (!ssh->savedhost)
-	fatalbox("Out of memory");
     strcpy(ssh->savedhost, host);
 
     if (port < 0)
@@ -2741,78 +2850,6 @@ static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
     }
 }
 
-/*
- * Username and password input, abstracted off into routines
- * reusable in several places - even between SSH-1 and SSH-2.
- */
-
-/* Set up a username or password input loop on a given buffer. */
-static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
-{
-    ssh->userpass_input_buffer = buffer;
-    ssh->userpass_input_buflen = buflen;
-    ssh->userpass_input_bufpos = 0;
-    ssh->userpass_input_echo = echo;
-}
-
-/*
- * Process some terminal data in the course of username/password
- * input. Returns >0 for success (line of input returned in
- * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
- * for inconclusive (keep waiting for more input please).
- */
-static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
-{
-    char c;
-
-    while (inlen--) {
-	switch (c = *in++) {
-	  case 10:
-	  case 13:
-	    ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
-	    ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
-	    return +1;
-	    break;
-	  case 8:
-	  case 127:
-	    if (ssh->userpass_input_bufpos > 0) {
-		if (ssh->userpass_input_echo)
-		    c_write_str(ssh, "\b \b");
-		ssh->userpass_input_bufpos--;
-	    }
-	    break;
-	  case 21:
-	  case 27:
-	    while (ssh->userpass_input_bufpos > 0) {
-		if (ssh->userpass_input_echo)
-		    c_write_str(ssh, "\b \b");
-		ssh->userpass_input_bufpos--;
-	    }
-	    break;
-	  case 3:
-	  case 4:
-	    return -1;
-	    break;
-	  default:
-	    /*
-	     * This simplistic check for printability is disabled
-	     * when we're doing password input, because some people
-	     * have control characters in their passwords.o
-	     */
-	    if ((!ssh->userpass_input_echo ||
-		 (c >= ' ' && c <= '~') ||
-		 ((unsigned char) c >= 160))
-		&& ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
-		ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
-		if (ssh->userpass_input_echo)
-		    c_write(ssh, &c, 1);
-	    }
-	    break;
-	}
-    }
-    return 0;
-}
-
 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
 {
     Ssh ssh = (Ssh) sshv;
@@ -2872,6 +2909,39 @@ static void ssh_agentf_callback(void *cv, void *reply, int replylen)
 }
 
 /*
+ * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
+ * non-NULL, otherwise just close the connection. `client_reason' == NULL
+ * => log `wire_reason'.
+ */
+static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
+			   int code, int clean_exit)
+{
+    char *error;
+    if (!client_reason)
+	client_reason = wire_reason;
+    if (client_reason)
+	error = dupprintf("Disconnected: %s", client_reason);
+    else
+	error = dupstr("Disconnected");
+    if (wire_reason) {
+	if (ssh->version == 1) {
+	    send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
+			PKT_END);
+	} else if (ssh->version == 2) {
+	    struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
+	    ssh2_pkt_adduint32(pktout, code);
+	    ssh2_pkt_addstring(pktout, wire_reason);
+	    ssh2_pkt_addstring(pktout, "en");	/* language tag */
+	    ssh2_pkt_send_noqueue(ssh, pktout);
+	}
+    }
+    ssh->close_expected = TRUE;
+    ssh->clean_exit = clean_exit;
+    ssh_closing((Plug)ssh, error, 0, 0);
+    sfree(error);
+}
+
+/*
  * Handle the key exchange and user authentication phases.
  */
 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
@@ -2892,9 +2962,9 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 	char username[100];
 	void *publickey_blob;
 	int publickey_bloblen;
-	char password[100];
-	char prompt[200];
-	int pos;
+	char *publickey_comment;
+	int publickey_encrypted;
+	prompts_t *cur_prompt;
 	char c;
 	int pwpkt_type;
 	unsigned char request[5], *response, *p;
@@ -2976,8 +3046,6 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
     s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
 
     s->rsabuf = snewn(s->len, unsigned char);
-    if (!s->rsabuf)
-	fatalbox("Out of memory");
 
     /*
      * Verify the host key.
@@ -2989,8 +3057,6 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 	int len = rsastr_len(&hostkey);
 	char fingerprint[100];
 	char *keystr = snewn(len, char);
-	if (!keystr)
-	    fatalbox("Out of memory");
 	rsastr_fmt(keystr, &hostkey);
 	rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
 
@@ -3014,8 +3080,8 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
         ssh_set_frozen(ssh, 0);
 
         if (s->dlgret == 0) {
-            ssh->close_expected = TRUE;
-            ssh_closing((Plug)ssh, NULL, 0, 0);
+	    ssh_disconnect(ssh, "User aborted at host key verification",
+			   NULL, 0, TRUE);
 	    crStop(0);
         }
     }
@@ -3095,8 +3161,8 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 	    }
             ssh_set_frozen(ssh, 0);
 	    if (s->dlgret == 0) {
-		ssh->close_expected = TRUE;
-		ssh_closing((Plug)ssh, NULL, 0, 0);
+		ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
+			       0, TRUE);
 		crStop(0);
 	    }
         }
@@ -3160,35 +3226,33 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 
     logevent("Successfully started encryption");
 
-    fflush(stdout);
+    fflush(stdout); /* FIXME eh? */
     {
 	if (!*ssh->cfg.username) {
-	    if (ssh_get_line && !ssh_getline_pw_only) {
-		if (!ssh_get_line("login as: ",
-				  s->username, sizeof(s->username), FALSE)) {
-		    /*
-		     * get_line failed to get a username.
-		     * Terminate.
-		     */
-		    logevent("No username provided. Abandoning session.");
-		    ssh->close_expected = TRUE;
-                    ssh_closing((Plug)ssh, NULL, 0, 0);
-		    crStop(1);
-		}
-	    } else {
-		int ret;	       /* need not be kept over crReturn */
-		c_write_str(ssh, "login as: ");
+	    int ret; /* need not be kept over crReturn */
+	    s->cur_prompt = new_prompts(ssh->frontend);
+	    s->cur_prompt->to_server = TRUE;
+	    s->cur_prompt->name = dupstr("SSH login name");
+	    add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
+		       lenof(s->username)); 
+	    ret = get_userpass_input(s->cur_prompt, NULL, 0);
+	    while (ret < 0) {
 		ssh->send_ok = 1;
-
-		setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
-		do {
-		    crWaitUntil(!pktin);
-		    ret = process_userpass_input(ssh, in, inlen);
-		} while (ret == 0);
-		if (ret < 0)
-		    cleanup_exit(0);
-		c_write_str(ssh, "\r\n");
+		crWaitUntil(!pktin);
+		ret = get_userpass_input(s->cur_prompt, in, inlen);
+		ssh->send_ok = 0;
+	    }
+	    if (!ret) {
+		/*
+		 * Failed to get a username. Terminate.
+		 */
+		free_prompts(s->cur_prompt);
+		ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
+		crStop(0);
 	    }
+	    memcpy(s->username, s->cur_prompt->prompts[0]->result,
+		   lenof(s->username));
+	    free_prompts(s->cur_prompt);
 	} else {
 	    strncpy(s->username, ssh->cfg.username, sizeof(s->username));
 	    s->username[sizeof(s->username)-1] = '\0';
@@ -3196,14 +3260,14 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 
 	send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
 	{
-	    char userlog[22 + sizeof(s->username)];
-	    sprintf(userlog, "Sent username \"%s\"", s->username);
+	    char *userlog = dupprintf("Sent username \"%s\"", s->username);
 	    logevent(userlog);
 	    if (flags & FLAG_INTERACTIVE &&
 		(!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
-		strcat(userlog, "\r\n");
 		c_write_str(ssh, userlog);
+		c_write_str(ssh, "\r\n");
 	    }
+	    sfree(userlog);
 	}
     }
 
@@ -3216,18 +3280,51 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 	s->tried_publickey = s->tried_agent = 0;
     }
     s->tis_auth_refused = s->ccard_auth_refused = 0;
-    /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
+    /*
+     * Load the public half of any configured keyfile for later use.
+     */
     if (!filename_is_null(ssh->cfg.keyfile)) {
-	if (!rsakey_pubblob(&ssh->cfg.keyfile,
-			    &s->publickey_blob, &s->publickey_bloblen, NULL))
+	int keytype;
+	logeventf(ssh, "Reading private key file \"%.150s\"",
+		  filename_to_str(&ssh->cfg.keyfile));
+	keytype = key_type(&ssh->cfg.keyfile);
+	if (keytype == SSH_KEYTYPE_SSH1) {
+	    const char *error;
+	    if (rsakey_pubblob(&ssh->cfg.keyfile,
+			       &s->publickey_blob, &s->publickey_bloblen,
+			       &s->publickey_comment, &error)) {
+		s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
+							  NULL);
+	    } else {
+		char *msgbuf;
+		logeventf(ssh, "Unable to load private key (%s)", error);
+		msgbuf = dupprintf("Unable to load private key file "
+				   "\"%.150s\" (%s)\r\n",
+				   filename_to_str(&ssh->cfg.keyfile),
+				   error);
+		c_write_str(ssh, msgbuf);
+		sfree(msgbuf);
+		s->publickey_blob = NULL;
+	    }
+	} else {
+	    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",
+			       filename_to_str(&ssh->cfg.keyfile),
+			       key_type_to_str(keytype));
+	    c_write_str(ssh, msgbuf);
+	    sfree(msgbuf);
 	    s->publickey_blob = NULL;
+	}
     } else
 	s->publickey_blob = NULL;
 
     while (pktin->type == SSH1_SMSG_FAILURE) {
 	s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
 
-	if (agent_exists() && !s->tried_agent) {
+	if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) {
 	    /*
 	     * Attempt RSA authentication using Pageant.
 	     */
@@ -3261,13 +3358,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 		s->p += 4;
 		logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
 		for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
-		    logeventf(ssh, "Trying Pageant key #%d", s->keyi);
-		    if (s->publickey_blob &&
-			!memcmp(s->p, s->publickey_blob,
-				s->publickey_bloblen)) {
-			logevent("This key matches configured key file");
-			s->tried_publickey = 1;
-		    }
+		    unsigned char *pkblob = s->p;
 		    s->p += 4;
 		    {
 			int n, ok = FALSE;
@@ -3300,6 +3391,17 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 			    break;
 			}
 		    }
+		    if (s->publickey_blob) {
+			if (!memcmp(pkblob, s->publickey_blob,
+				    s->publickey_bloblen)) {
+			    logeventf(ssh, "Pageant key #%d matches "
+				      "configured key file", s->keyi);
+			    s->tried_publickey = 1;
+			} else
+			    /* Skip non-configured key */
+			    continue;
+		    }
+		    logeventf(ssh, "Trying Pageant key #%d", s->keyi);
 		    send_packet(ssh, SSH1_CMSG_AUTH_RSA,
 				PKT_BIGNUM, s->key.modulus, PKT_END);
 		    crWaitUntil(pktin);
@@ -3390,12 +3492,156 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 			break;
 		}
 		sfree(s->response);
+		if (s->publickey_blob && !s->tried_publickey)
+		    logevent("Configured key file not in Pageant");
 	    }
 	    if (s->authed)
 		break;
 	}
-	if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
-	    s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
+	if (s->publickey_blob && !s->tried_publickey) {
+	    /*
+	     * Try public key authentication with the specified
+	     * key file.
+	     */
+	    int got_passphrase; /* need not be kept over crReturn */
+	    if (flags & FLAG_VERBOSE)
+		c_write_str(ssh, "Trying public key authentication.\r\n");
+	    logeventf(ssh, "Trying public key \"%s\"",
+		      filename_to_str(&ssh->cfg.keyfile));
+	    s->tried_publickey = 1;
+	    got_passphrase = FALSE;
+	    while (!got_passphrase) {
+		/*
+		 * Get a passphrase, if necessary.
+		 */
+		char *passphrase = NULL;    /* only written after crReturn */
+		const char *error;
+		if (!s->publickey_encrypted) {
+		    if (flags & FLAG_VERBOSE)
+			c_write_str(ssh, "No passphrase required.\r\n");
+		    passphrase = NULL;
+		} else {
+		    int ret; /* need not be kept over crReturn */
+		    s->cur_prompt = new_prompts(ssh->frontend);
+		    s->cur_prompt->to_server = FALSE;
+		    s->cur_prompt->name = dupstr("SSH key passphrase");
+		    add_prompt(s->cur_prompt,
+			       dupprintf("Passphrase for key \"%.100s\": ",
+					 s->publickey_comment),
+			       FALSE, SSH_MAX_PASSWORD_LEN);
+		    ret = get_userpass_input(s->cur_prompt, NULL, 0);
+		    while (ret < 0) {
+			ssh->send_ok = 1;
+			crWaitUntil(!pktin);
+			ret = get_userpass_input(s->cur_prompt, in, inlen);
+			ssh->send_ok = 0;
+		    }
+		    if (!ret) {
+			/* Failed to get a passphrase. Terminate. */
+			free_prompts(s->cur_prompt);
+			ssh_disconnect(ssh, NULL, "Unable to authenticate",
+				       0, TRUE);
+			crStop(0);
+		    }
+		    passphrase = dupstr(s->cur_prompt->prompts[0]->result);
+		    free_prompts(s->cur_prompt);
+		}
+		/*
+		 * Try decrypting key with passphrase.
+		 */
+		ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
+				 &error);
+		if (passphrase) {
+		    memset(passphrase, 0, strlen(passphrase));
+		    sfree(passphrase);
+		}
+		if (ret == 1) {
+		    /* Correct passphrase. */
+		    got_passphrase = TRUE;
+		} else if (ret == 0) {
+		    c_write_str(ssh, "Couldn't load private key from ");
+		    c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
+		    c_write_str(ssh, " (");
+		    c_write_str(ssh, error);
+		    c_write_str(ssh, ").\r\n");
+		    got_passphrase = FALSE;
+		    break;	       /* go and try something else */
+		} else if (ret == -1) {
+		    c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
+		    got_passphrase = FALSE;
+		    /* and try again */
+		} else {
+		    assert(0 && "unexpected return from loadrsakey()");
+		    got_passphrase = FALSE;   /* placate optimisers */
+		}
+	    }
+
+	    if (got_passphrase) {
+
+		/*
+		 * Send a public key attempt.
+		 */
+		send_packet(ssh, SSH1_CMSG_AUTH_RSA,
+			    PKT_BIGNUM, s->key.modulus, PKT_END);
+
+		crWaitUntil(pktin);
+		if (pktin->type == SSH1_SMSG_FAILURE) {
+		    c_write_str(ssh, "Server refused our public key.\r\n");
+		    continue;	       /* go and try something else */
+		}
+		if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
+		    bombout(("Bizarre response to offer of public key"));
+		    crStop(0);
+		}
+
+		{
+		    int i;
+		    unsigned char buffer[32];
+		    Bignum challenge, response;
+
+		    if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
+			bombout(("Server's RSA challenge was badly formatted"));
+			crStop(0);
+		    }
+		    response = rsadecrypt(challenge, &s->key);
+		    freebn(s->key.private_exponent);/* burn the evidence */
+
+		    for (i = 0; i < 32; i++) {
+			buffer[i] = bignum_byte(response, 31 - i);
+		    }
+
+		    MD5Init(&md5c);
+		    MD5Update(&md5c, buffer, 32);
+		    MD5Update(&md5c, s->session_id, 16);
+		    MD5Final(buffer, &md5c);
+
+		    send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
+				PKT_DATA, buffer, 16, PKT_END);
+
+		    freebn(challenge);
+		    freebn(response);
+		}
+
+		crWaitUntil(pktin);
+		if (pktin->type == SSH1_SMSG_FAILURE) {
+		    if (flags & FLAG_VERBOSE)
+			c_write_str(ssh, "Failed to authenticate with"
+				    " our public key.\r\n");
+		    continue;	       /* go and try something else */
+		} else if (pktin->type != SSH1_SMSG_SUCCESS) {
+		    bombout(("Bizarre response to RSA authentication response"));
+		    crStop(0);
+		}
+
+		break;		       /* we're through! */
+	    }
+
+	}
+
+	/*
+	 * Otherwise, try various forms of password-like authentication.
+	 */
+	s->cur_prompt = new_prompts(ssh->frontend);
 
 	if (ssh->cfg.try_tis_auth &&
 	    (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
@@ -3413,23 +3659,31 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 	    } else {
 		char *challenge;
 		int challengelen;
+		char *instr_suf, *prompt;
 
 		ssh_pkt_getstring(pktin, &challenge, &challengelen);
 		if (!challenge) {
 		    bombout(("TIS challenge packet was badly formed"));
 		    crStop(0);
 		}
-		c_write_str(ssh, "Using TIS authentication.\r\n");
 		logevent("Received TIS challenge");
-		if (challengelen > sizeof(s->prompt) - 1)
-		    challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
-		memcpy(s->prompt, challenge, challengelen);
+		s->cur_prompt->to_server = TRUE;
+		s->cur_prompt->name = dupstr("SSH TIS authentication");
 		/* Prompt heuristic comes from OpenSSH */
-		strncpy(s->prompt + challengelen,
-		        memchr(s->prompt, '\n', challengelen) ?
-			"": "\r\nResponse: ",
-			(sizeof s->prompt) - challengelen);
-		s->prompt[(sizeof s->prompt) - 1] = '\0';
+		if (memchr(challenge, '\n', challengelen)) {
+		    instr_suf = dupstr("");
+		    prompt = dupprintf("%.*s", challengelen, challenge);
+		} else {
+		    instr_suf = dupprintf("%.*s", challengelen, challenge);
+		    prompt = dupstr("Response: ");
+		}
+		s->cur_prompt->instruction =
+		    dupprintf("Using TIS authentication.%s%s",
+			      (*instr_suf) ? "\n" : "",
+			      instr_suf);
+		s->cur_prompt->instr_reqd = TRUE;
+		add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
+		sfree(instr_suf);
 	    }
 	}
 	if (ssh->cfg.try_tis_auth &&
@@ -3447,53 +3701,40 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 	    } else {
 		char *challenge;
 		int challengelen;
+		char *instr_suf, *prompt;
 
 		ssh_pkt_getstring(pktin, &challenge, &challengelen);
 		if (!challenge) {
 		    bombout(("CryptoCard challenge packet was badly formed"));
 		    crStop(0);
 		}
-		c_write_str(ssh, "Using CryptoCard authentication.\r\n");
 		logevent("Received CryptoCard challenge");
-		if (challengelen > sizeof(s->prompt) - 1)
-		    challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
-		memcpy(s->prompt, challenge, challengelen);
-		strncpy(s->prompt + challengelen,
-		        memchr(s->prompt, '\n', challengelen) ?
-			"" : "\r\nResponse: ",
-			sizeof(s->prompt) - challengelen);
-		s->prompt[sizeof(s->prompt) - 1] = '\0';
+		s->cur_prompt->to_server = TRUE;
+		s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
+		s->cur_prompt->name_reqd = FALSE;
+		/* Prompt heuristic comes from OpenSSH */
+		if (memchr(challenge, '\n', challengelen)) {
+		    instr_suf = dupstr("");
+		    prompt = dupprintf("%.*s", challengelen, challenge);
+		} else {
+		    instr_suf = dupprintf("%.*s", challengelen, challenge);
+		    prompt = dupstr("Response: ");
+		}
+		s->cur_prompt->instruction =
+		    dupprintf("Using CryptoCard authentication.%s%s",
+			      (*instr_suf) ? "\n" : "",
+			      instr_suf);
+		s->cur_prompt->instr_reqd = TRUE;
+		add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
+		sfree(instr_suf);
 	    }
 	}
 	if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
-	    sprintf(s->prompt, "%.90s@%.90s's password: ",
-		    s->username, ssh->savedhost);
-	}
-	if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
-	    char *comment = NULL;
-	    int type;
-	    if (flags & FLAG_VERBOSE)
-		c_write_str(ssh, "Trying public key authentication.\r\n");
-	    logeventf(ssh, "Trying public key \"%s\"",
-		      filename_to_str(&ssh->cfg.keyfile));
-	    type = key_type(&ssh->cfg.keyfile);
-	    if (type != SSH_KEYTYPE_SSH1) {
-		char *msg = dupprintf("Key is of wrong type (%s)",
-				      key_type_to_str(type));
-		logevent(msg);
-		c_write_str(ssh, msg);
-		c_write_str(ssh, "\r\n");
-		sfree(msg);
-		s->tried_publickey = 1;
-		continue;
-	    }
-	    if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
-		if (flags & FLAG_VERBOSE)
-		    c_write_str(ssh, "No passphrase required.\r\n");
-		goto tryauth;
-	    }
-	    sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
-	    sfree(comment);
+	    s->cur_prompt->to_server = TRUE;
+	    s->cur_prompt->name = dupstr("SSH password");
+	    add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
+						s->username, ssh->savedhost),
+		       FALSE, SSH_MAX_PASSWORD_LEN);
 	}
 
 	/*
@@ -3501,251 +3742,153 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 	 * or CryptoCard exchange if we're doing TIS or CryptoCard
 	 * authentication.
 	 */
-	if (ssh_get_line) {
-	    if (!ssh_get_line(s->prompt, s->password,
-			      sizeof(s->password), TRUE)) {
+	{
+	    int ret; /* need not be kept over crReturn */
+	    ret = get_userpass_input(s->cur_prompt, NULL, 0);
+	    while (ret < 0) {
+		ssh->send_ok = 1;
+		crWaitUntil(!pktin);
+		ret = get_userpass_input(s->cur_prompt, in, inlen);
+		ssh->send_ok = 0;
+	    }
+	    if (!ret) {
 		/*
-		 * get_line failed to get a password (for example
+		 * Failed to get a password (for example
 		 * because one was supplied on the command line
 		 * which has already failed to work). Terminate.
 		 */
-		send_packet(ssh, SSH1_MSG_DISCONNECT,
-			    PKT_STR, "No more passwords available to try",
-			    PKT_END);
-		logevent("Unable to authenticate");
-		connection_fatal(ssh->frontend, "Unable to authenticate");
-		ssh->close_expected = TRUE;
-                ssh_closing((Plug)ssh, NULL, 0, 0);
-		crStop(1);
+		free_prompts(s->cur_prompt);
+		ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
+		crStop(0);
 	    }
-	} else {
-	    /* Prompt may have come from server. We've munged it a bit, so
-	     * we know it to be zero-terminated at least once. */
-	    int ret;		       /* need not be saved over crReturn */
-	    c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
-	    s->pos = 0;
-
-	    setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
-	    do {
-		crWaitUntil(!pktin);
-		ret = process_userpass_input(ssh, in, inlen);
-	    } while (ret == 0);
-	    if (ret < 0)
-		cleanup_exit(0);
-	    c_write_str(ssh, "\r\n");
 	}
 
-      tryauth:
-	if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
-	    /*
-	     * Try public key authentication with the specified
-	     * key file.
-	     */
-	    s->tried_publickey = 1;
-	    
-	    {
-		const char *error = NULL;
-		int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
-				     &error);
-		if (ret == 0) {
-		    c_write_str(ssh, "Couldn't load private key from ");
-		    c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
-		    c_write_str(ssh, " (");
-		    c_write_str(ssh, error);
-		    c_write_str(ssh, ").\r\n");
-		    continue;	       /* go and try password */
-		}
-		if (ret == -1) {
-		    c_write_str(ssh, "Wrong passphrase.\r\n");
-		    s->tried_publickey = 0;
-		    continue;	       /* try again */
-		}
-	    }
-
+	if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
 	    /*
-	     * Send a public key attempt.
+	     * Defence against traffic analysis: we send a
+	     * whole bunch of packets containing strings of
+	     * different lengths. One of these strings is the
+	     * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
+	     * The others are all random data in
+	     * SSH1_MSG_IGNORE packets. This way a passive
+	     * listener can't tell which is the password, and
+	     * hence can't deduce the password length.
+	     * 
+	     * Anybody with a password length greater than 16
+	     * bytes is going to have enough entropy in their
+	     * password that a listener won't find it _that_
+	     * much help to know how long it is. So what we'll
+	     * do is:
+	     * 
+	     *  - if password length < 16, we send 15 packets
+	     *    containing string lengths 1 through 15
+	     * 
+	     *  - otherwise, we let N be the nearest multiple
+	     *    of 8 below the password length, and send 8
+	     *    packets containing string lengths N through
+	     *    N+7. This won't obscure the order of
+	     *    magnitude of the password length, but it will
+	     *    introduce a bit of extra uncertainty.
+	     * 
+	     * A few servers can't deal with SSH1_MSG_IGNORE, at
+	     * least in this context. For these servers, we need
+	     * an alternative defence. We make use of the fact
+	     * that the password is interpreted as a C string:
+	     * so we can append a NUL, then some random data.
+	     * 
+	     * A few servers can deal with neither SSH1_MSG_IGNORE
+	     * here _nor_ a padded password string.
+	     * For these servers we are left with no defences
+	     * against password length sniffing.
 	     */
-	    send_packet(ssh, SSH1_CMSG_AUTH_RSA,
-			PKT_BIGNUM, s->key.modulus, PKT_END);
+	    if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
+	        !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
+		/*
+		 * The server can deal with SSH1_MSG_IGNORE, so
+		 * we can use the primary defence.
+		 */
+		int bottom, top, pwlen, i;
+		char *randomstr;
 
-	    crWaitUntil(pktin);
-	    if (pktin->type == SSH1_SMSG_FAILURE) {
-		c_write_str(ssh, "Server refused our public key.\r\n");
-		continue;	       /* go and try password */
-	    }
-	    if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
-		bombout(("Bizarre response to offer of public key"));
-		crStop(0);
-	    }
+		pwlen = strlen(s->cur_prompt->prompts[0]->result);
+		if (pwlen < 16) {
+		    bottom = 0;    /* zero length passwords are OK! :-) */
+		    top = 15;
+		} else {
+		    bottom = pwlen & ~7;
+		    top = bottom + 7;
+		}
 
-	    {
-		int i;
-		unsigned char buffer[32];
-		Bignum challenge, response;
+		assert(pwlen >= bottom && pwlen <= top);
 
-		if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
-		    bombout(("Server's RSA challenge was badly formatted"));
-		    crStop(0);
-		}
-		response = rsadecrypt(challenge, &s->key);
-		freebn(s->key.private_exponent);/* burn the evidence */
+		randomstr = snewn(top + 1, char);
 
-		for (i = 0; i < 32; i++) {
-		    buffer[i] = bignum_byte(response, 31 - i);
-		}
-
-		MD5Init(&md5c);
-		MD5Update(&md5c, buffer, 32);
-		MD5Update(&md5c, s->session_id, 16);
-		MD5Final(buffer, &md5c);
-
-		send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
-			    PKT_DATA, buffer, 16, PKT_END);
-
-		freebn(challenge);
-		freebn(response);
-	    }
-
-	    crWaitUntil(pktin);
-	    if (pktin->type == SSH1_SMSG_FAILURE) {
-		if (flags & FLAG_VERBOSE)
-		    c_write_str(ssh, "Failed to authenticate with"
-				" our public key.\r\n");
-		continue;	       /* go and try password */
-	    } else if (pktin->type != SSH1_SMSG_SUCCESS) {
-		bombout(("Bizarre response to RSA authentication response"));
-		crStop(0);
-	    }
-
-	    break;		       /* we're through! */
-	} else {
-	    if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
-		/*
-		 * Defence against traffic analysis: we send a
-		 * whole bunch of packets containing strings of
-		 * different lengths. One of these strings is the
-		 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
-		 * The others are all random data in
-		 * SSH1_MSG_IGNORE packets. This way a passive
-		 * listener can't tell which is the password, and
-		 * hence can't deduce the password length.
-		 * 
-		 * Anybody with a password length greater than 16
-		 * bytes is going to have enough entropy in their
-		 * password that a listener won't find it _that_
-		 * much help to know how long it is. So what we'll
-		 * do is:
-		 * 
-		 *  - if password length < 16, we send 15 packets
-		 *    containing string lengths 1 through 15
-		 * 
-		 *  - otherwise, we let N be the nearest multiple
-		 *    of 8 below the password length, and send 8
-		 *    packets containing string lengths N through
-		 *    N+7. This won't obscure the order of
-		 *    magnitude of the password length, but it will
-		 *    introduce a bit of extra uncertainty.
-		 * 
-		 * A few servers (the old 1.2.18 through 1.2.22)
-		 * can't deal with SSH1_MSG_IGNORE. For these
-		 * servers, we need an alternative defence. We make
-		 * use of the fact that the password is interpreted
-		 * as a C string: so we can append a NUL, then some
-		 * random data.
-		 * 
-		 * One server (a Cisco one) can deal with neither
-		 * SSH1_MSG_IGNORE _nor_ a padded password string.
-		 * For this server we are left with no defences
-		 * against password length sniffing.
-		 */
-		if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
-		    /*
-		     * The server can deal with SSH1_MSG_IGNORE, so
-		     * we can use the primary defence.
-		     */
-		    int bottom, top, pwlen, i;
-		    char *randomstr;
-
-		    pwlen = strlen(s->password);
-		    if (pwlen < 16) {
-			bottom = 0;    /* zero length passwords are OK! :-) */
-			top = 15;
+		for (i = bottom; i <= top; i++) {
+		    if (i == pwlen) {
+			defer_packet(ssh, s->pwpkt_type,
+				     PKTT_PASSWORD, PKT_STR,
+				     s->cur_prompt->prompts[0]->result,
+				     PKTT_OTHER, PKT_END);
 		    } else {
-			bottom = pwlen & ~7;
-			top = bottom + 7;
-		    }
-
-		    assert(pwlen >= bottom && pwlen <= top);
-
-		    randomstr = snewn(top + 1, char);
-
-		    for (i = bottom; i <= top; i++) {
-			if (i == pwlen) {
-			    defer_packet(ssh, s->pwpkt_type,
-					 PKTT_PASSWORD, PKT_STR, s->password,
-					 PKTT_OTHER, PKT_END);
-			} else {
-			    for (j = 0; j < i; j++) {
-				do {
-				    randomstr[j] = random_byte();
-				} while (randomstr[j] == '\0');
-			    }
-			    randomstr[i] = '\0';
-			    defer_packet(ssh, SSH1_MSG_IGNORE,
-					 PKT_STR, randomstr, PKT_END);
+			for (j = 0; j < i; j++) {
+			    do {
+				randomstr[j] = random_byte();
+			    } while (randomstr[j] == '\0');
 			}
+			randomstr[i] = '\0';
+			defer_packet(ssh, SSH1_MSG_IGNORE,
+				     PKT_STR, randomstr, PKT_END);
 		    }
-		    logevent("Sending password with camouflage packets");
-		    ssh_pkt_defersend(ssh);
-		    sfree(randomstr);
-		} 
-		else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
-		    /*
-		     * The server can't deal with SSH1_MSG_IGNORE
-		     * but can deal with padded passwords, so we
-		     * can use the secondary defence.
-		     */
-		    char string[64];
-		    char *ss;
-		    int len;
-
-		    len = strlen(s->password);
-		    if (len < sizeof(string)) {
-			ss = string;
-			strcpy(string, s->password);
-			len++;	       /* cover the zero byte */
-			while (len < sizeof(string)) {
-			    string[len++] = (char) random_byte();
-			}
-		    } else {
-			ss = s->password;
+		}
+		logevent("Sending password with camouflage packets");
+		ssh_pkt_defersend(ssh);
+		sfree(randomstr);
+	    } 
+	    else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
+		/*
+		 * The server can't deal with SSH1_MSG_IGNORE
+		 * but can deal with padded passwords, so we
+		 * can use the secondary defence.
+		 */
+		char string[64];
+		char *ss;
+		int len;
+
+		len = strlen(s->cur_prompt->prompts[0]->result);
+		if (len < sizeof(string)) {
+		    ss = string;
+		    strcpy(string, s->cur_prompt->prompts[0]->result);
+		    len++;	       /* cover the zero byte */
+		    while (len < sizeof(string)) {
+			string[len++] = (char) random_byte();
 		    }
-		    logevent("Sending length-padded password");
-		    send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
-				PKT_INT, len, PKT_DATA, ss, len,
-			       	PKTT_OTHER, PKT_END);
 		} else {
-		    /*
-		     * The server has _both_
-		     * BUG_CHOKES_ON_SSH1_IGNORE and
-		     * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
-		     * therefore nothing we can do.
-		     */
-		    int len;
-		    len = strlen(s->password);
-		    logevent("Sending unpadded password");
-		    send_packet(ssh, s->pwpkt_type,
-				PKTT_PASSWORD, PKT_INT, len,
-				PKT_DATA, s->password, len,
-				PKTT_OTHER, PKT_END);
+		    ss = s->cur_prompt->prompts[0]->result;
 		}
-	    } else {
+		logevent("Sending length-padded password");
 		send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
-			    PKT_STR, s->password, PKTT_OTHER, PKT_END);
+			    PKT_INT, len, PKT_DATA, ss, len,
+			    PKTT_OTHER, PKT_END);
+	    } else {
+		/*
+		 * The server is believed unable to cope with
+		 * any of our password camouflage methods.
+		 */
+		int len;
+		len = strlen(s->cur_prompt->prompts[0]->result);
+		logevent("Sending unpadded password");
+		send_packet(ssh, s->pwpkt_type,
+			    PKTT_PASSWORD, PKT_INT, len,
+			    PKT_DATA, s->cur_prompt->prompts[0]->result, len,
+			    PKTT_OTHER, PKT_END);
 	    }
+	} else {
+	    send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
+			PKT_STR, s->cur_prompt->prompts[0]->result,
+			PKTT_OTHER, PKT_END);
 	}
 	logevent("Sent password");
-	memset(s->password, 0, strlen(s->password));
+	free_prompts(s->cur_prompt);
 	crWaitUntil(pktin);
 	if (pktin->type == SSH1_SMSG_FAILURE) {
 	    if (flags & FLAG_VERBOSE)
@@ -3757,6 +3900,12 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
 	}
     }
 
+    /* Clear up */
+    if (s->publickey_blob) {
+	sfree(s->publickey_blob);
+	sfree(s->publickey_comment);
+    }
+
     logevent("Authentication successful");
 
     crFinish(1);
@@ -4505,7 +4654,7 @@ static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
 	    /* Data for an agent message. Buffer it. */
 	    while (len > 0) {
 		if (c->u.a.lensofar < 4) {
-		    unsigned int l = min(4 - c->u.a.lensofar, len);
+		    unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
 		    memcpy(c->u.a.msglen + c->u.a.lensofar, p,
 			   l);
 		    p += l;
@@ -4522,7 +4671,7 @@ static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
 		if (c->u.a.lensofar >= 4 && len > 0) {
 		    unsigned int l =
 			min(c->u.a.totallen - c->u.a.lensofar,
-			    len);
+			    (unsigned)len);
 		    memcpy(c->u.a.message + c->u.a.lensofar, p,
 			   l);
 		    p += l;
@@ -4563,8 +4712,7 @@ static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
      * encrypted packet, we close the session once
      * we've sent EXIT_CONFIRMATION.
      */
-    ssh->close_expected = TRUE;
-    ssh_closing((Plug)ssh, NULL, 0, 0);
+    ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
 }
 
 /* Helper function to deal with sending tty modes for REQUEST_PTY */
@@ -4632,14 +4780,23 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
 	ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
 				       data, sizeof(data), ssh->cfg.x11_auth);
         x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
+	/*
+	 * Note that while we blank the X authentication data here, we don't
+	 * take any special action to blank the start of an X11 channel,
+	 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
+	 * without having session blanking enabled is likely to leak your
+	 * cookie into the log.
+	 */
 	if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
 	    send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
-			PKT_STR, proto, PKT_STR, data,
+			PKT_STR, proto,
+			PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
 			PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
 			PKT_END);
 	} else {
 	    send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
-			PKT_STR, proto, PKT_STR, data, PKT_END);
+			PKT_STR, proto,
+			PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
 	}
 	do {
 	    crReturnV;
@@ -4908,27 +5065,30 @@ static int first_in_commasep_string(char *needle, char *haystack, int haylen)
 
 /*
  * SSH-2 key creation method.
+ * (Currently assumes 2 lots of any hash are sufficient to generate
+ * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
  */
-static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
-		       unsigned char *sessid, char chr,
+#define SSH2_MKKEY_ITERS (2)
+static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
 		       unsigned char *keyspace)
 {
-    SHA_State s;
-    /* First 20 bytes. */
-    SHA_Init(&s);
+    const struct ssh_hash *h = ssh->kex->hash;
+    void *s;
+    /* First hlen bytes. */
+    s = h->init();
     if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
-	sha_mpint(&s, K);
-    SHA_Bytes(&s, H, 20);
-    SHA_Bytes(&s, &chr, 1);
-    SHA_Bytes(&s, sessid, 20);
-    SHA_Final(&s, keyspace);
-    /* Next 20 bytes. */
-    SHA_Init(&s);
+	hash_mpint(h, s, K);
+    h->bytes(s, H, h->hlen);
+    h->bytes(s, &chr, 1);
+    h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
+    h->final(s, keyspace);
+    /* Next hlen bytes. */
+    s = h->init();
     if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
-	sha_mpint(&s, K);
-    SHA_Bytes(&s, H, 20);
-    SHA_Bytes(&s, keyspace, 20);
-    SHA_Final(&s, keyspace + 20);
+	hash_mpint(h, s, K);
+    h->bytes(s, H, h->hlen);
+    h->bytes(s, keyspace, h->hlen);
+    h->final(s, keyspace + h->hlen);
 }
 
 /*
@@ -4941,6 +5101,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
     struct do_ssh2_transport_state {
 	int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
 	Bignum p, g, e, f, K;
+	void *our_kexinit;
+	int our_kexinitlen;
 	int kex_init_value, kex_reply_value;
 	const struct ssh_mac **maclist;
 	int nmacs;
@@ -4950,12 +5112,13 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 	const struct ssh_mac *scmac_tobe;
 	const struct ssh_compress *cscomp_tobe;
 	const struct ssh_compress *sccomp_tobe;
-	char *hostkeydata, *sigdata, *keystr, *fingerprint;
-	int hostkeylen, siglen;
+	char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
+	int hostkeylen, siglen, rsakeylen;
 	void *hkey;		       /* actual host key */
-	unsigned char exchange_hash[20];
+	void *rsakey;		       /* for RSA kex */
+	unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
 	int n_preferred_kex;
-	const struct ssh_kex *preferred_kex[KEX_MAX];
+	const struct ssh_kexes *preferred_kex[KEX_MAX];
 	int n_preferred_ciphers;
 	const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
 	const struct ssh_compress *preferred_comp;
@@ -5006,7 +5169,11 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 		s->preferred_kex[s->n_preferred_kex++] =
 		    &ssh_diffiehellman_group1;
 		break;
-	      case CIPHER_WARN:
+	      case KEX_RSA:
+		s->preferred_kex[s->n_preferred_kex++] =
+		    &ssh_rsa_kex;
+		break;
+	      case KEX_WARN:
 		/* Flag for later. Don't bother if it's the last in
 		 * the list. */
 		if (i < KEX_MAX - 1) {
@@ -5078,12 +5245,14 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 	ssh2_pkt_addstring_start(s->pktout);
 	commalist_started = 0;
 	for (i = 0; i < s->n_preferred_kex; i++) {
-	    const struct ssh_kex *k = s->preferred_kex[i];
+	    const struct ssh_kexes *k = s->preferred_kex[i];
 	    if (!k) continue;	       /* warning flag */
-	    if (commalist_started)
-		ssh2_pkt_addstring_str(s->pktout, ",");
-	    ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
-	    commalist_started = 1;
+	    for (j = 0; j < k->nkexes; j++) {
+		if (commalist_started)
+		    ssh2_pkt_addstring_str(s->pktout, ",");
+		ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
+		commalist_started = 1;
+	    }
 	}
 	/* List server host key algorithms. */
 	ssh2_pkt_addstring_start(s->pktout);
@@ -5164,15 +5333,14 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 	ssh2_pkt_adduint32(s->pktout, 0);
     }
 
-    ssh->exhash = ssh->exhashbase;
-    sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
+    s->our_kexinitlen = s->pktout->length - 5;
+    s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
+    memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen); 
 
     ssh2_pkt_send_noqueue(ssh, s->pktout);
 
     if (!pktin)
 	crWaitUntil(pktin);
-    if (pktin->length > 5)
-	sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
 
     /*
      * Now examine the other side's KEXINIT to see what we're up
@@ -5201,13 +5369,17 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 
 	preferred = NULL;
 	for (i = 0; i < s->n_preferred_kex; i++) {
-	    const struct ssh_kex *k = s->preferred_kex[i];
+	    const struct ssh_kexes *k = s->preferred_kex[i];
 	    if (!k) {
 		s->warn_kex = TRUE;
 	    } else {
-		if (!preferred) preferred = k->name;
-		if (in_commasep_string(k->name, str, len))
-		    ssh->kex = k;
+		for (j = 0; j < k->nkexes; j++) {
+		    if (!preferred) preferred = k->list[j]->name;
+		    if (in_commasep_string(k->list[j]->name, str, len)) {
+			ssh->kex = k->list[j];
+			break;
+		    }
+		}
 	    }
 	    if (ssh->kex)
 		break;
@@ -5330,8 +5502,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 	    }
 	    ssh_set_frozen(ssh, 0);
 	    if (s->dlgret == 0) {
-		ssh->close_expected = TRUE;
-		ssh_closing((Plug)ssh, NULL, 0, 0);
+		ssh_disconnect(ssh, "User aborted at kex warning", NULL,
+			       0, TRUE);
 		crStop(0);
 	    }
 	}
@@ -5355,8 +5527,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 	    }
 	    ssh_set_frozen(ssh, 0);
 	    if (s->dlgret == 0) {
-		ssh->close_expected = TRUE;
-		ssh_closing((Plug)ssh, NULL, 0, 0);
+		ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
+			       0, TRUE);
 		crStop(0);
 	    }
 	}
@@ -5380,16 +5552,28 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 	    }
 	    ssh_set_frozen(ssh, 0);
 	    if (s->dlgret == 0) {
-		ssh->close_expected = TRUE;
-		ssh_closing((Plug)ssh, NULL, 0, 0);
+		ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
+			       0, TRUE);
 		crStop(0);
 	    }
 	}
 
+	ssh->exhash = ssh->kex->hash->init();
+	hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
+	hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
+	hash_string(ssh->kex->hash, ssh->exhash,
+	    s->our_kexinit, s->our_kexinitlen);
+	sfree(s->our_kexinit);
+	if (pktin->length > 5)
+	    hash_string(ssh->kex->hash, ssh->exhash,
+		pktin->data + 5, pktin->length - 5);
+
 	if (s->ignorepkt) /* first_kex_packet_follows */
 	    crWaitUntil(pktin);                /* Ignore packet */
     }
 
+    if (ssh->kex->main_type == KEXTYPE_DH) {
+	/* XXX The lines below should be reindented before this is committed.*/
     /*
      * Work out the number of bits of key we will need from the key
      * exchange. We start with the maximum key length of either
@@ -5402,10 +5586,10 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 	scbits = s->sccipher_tobe->keylen;
 	s->nbits = (csbits > scbits ? csbits : scbits);
     }
-    /* The keys only have 160-bit entropy, since they're based on
-     * a SHA-1 hash. So cap the key size at 160 bits. */
-    if (s->nbits > 160)
-	s->nbits = 160;
+    /* The keys only have hlen-bit entropy, since they're based on
+     * a hash. So cap the key size at hlen bits. */
+    if (s->nbits > ssh->kex->hash->hlen * 8)
+	s->nbits = ssh->kex->hash->hlen * 8;
 
     /*
      * If we're doing Diffie-Hellman group exchange, start by
@@ -5446,7 +5630,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 		  ssh->kex->groupname);
     }
 
-    logevent("Doing Diffie-Hellman key exchange");
+    logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
+             ssh->kex->hash->text_name);
     /*
      * Now generate and send e for Diffie-Hellman.
      */
@@ -5464,6 +5649,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
     }
     set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
     ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
+    s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
     s->f = ssh2_pkt_getmp(pktin);
     if (!s->f) {
 	bombout(("unable to parse key exchange reply packet"));
@@ -5477,29 +5663,139 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
      * involve user interaction. */
     set_busy_status(ssh->frontend, BUSY_NOT);
 
-    sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
-    if (ssh->kex == &ssh_diffiehellman_gex) {
-	sha_uint32(&ssh->exhash, s->pbits);
-	sha_mpint(&ssh->exhash, s->p);
-	sha_mpint(&ssh->exhash, s->g);
+    hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
+    if (!ssh->kex->pdata) {
+	hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
+	hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
+	hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
     }
-    sha_mpint(&ssh->exhash, s->e);
-    sha_mpint(&ssh->exhash, s->f);
-    sha_mpint(&ssh->exhash, s->K);
-    SHA_Final(&ssh->exhash, s->exchange_hash);
+    hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
+    hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
 
     dh_cleanup(ssh->kex_ctx);
+    freebn(s->f);
+    if (!ssh->kex->pdata) {
+        freebn(s->g);
+	freebn(s->p);
+    }
+        /* XXX end incorrectly-indented section */
+    } else {
+	logeventf(ssh, "Doing RSA key exchange with hash %s",
+		  ssh->kex->hash->text_name);
+	ssh->pkt_ctx |= SSH2_PKTCTX_RSAKEX;
+        /*
+         * RSA key exchange. First expect a KEXRSA_PUBKEY packet
+         * from the server.
+         */
+        crWaitUntil(pktin);
+        if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
+            bombout(("expected RSA public key packet from server"));
+            crStop(0);
+        }
+
+        ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
+        hash_string(ssh->kex->hash, ssh->exhash,
+		    s->hostkeydata, s->hostkeylen);
+	s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
+
+        {
+            char *keydata;
+            ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
+            s->rsakeydata = snewn(s->rsakeylen, char);
+            memcpy(s->rsakeydata, keydata, s->rsakeylen);
+        }
+
+        s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
+        if (!s->rsakey) {
+            sfree(s->rsakeydata);
+            bombout(("unable to parse RSA public key from server"));
+            crStop(0);
+        }
+
+        hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
+
+        /*
+         * Next, set up a shared secret K, of precisely KLEN -
+         * 2*HLEN - 49 bits, where KLEN is the bit length of the
+         * RSA key modulus and HLEN is the bit length of the hash
+         * we're using.
+         */
+        {
+            int klen = ssh_rsakex_klen(s->rsakey);
+            int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
+            int i, byte = 0;
+            unsigned char *kstr1, *kstr2, *outstr;
+            int kstr1len, kstr2len, outstrlen;
+
+            s->K = bn_power_2(nbits - 1);
+
+            for (i = 0; i < nbits; i++) {
+                if ((i & 7) == 0) {
+                    byte = random_byte();
+                }
+                bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
+            }
+
+            /*
+             * Encode this as an mpint.
+             */
+            kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
+            kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
+            PUT_32BIT(kstr2, kstr1len);
+            memcpy(kstr2 + 4, kstr1, kstr1len);
+
+            /*
+             * Encrypt it with the given RSA key.
+             */
+            outstrlen = (klen + 7) / 8;
+            outstr = snewn(outstrlen, unsigned char);
+            ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
+			       outstr, outstrlen, s->rsakey);
+
+            /*
+             * And send it off in a return packet.
+             */
+            s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
+            ssh2_pkt_addstring_start(s->pktout);
+            ssh2_pkt_addstring_data(s->pktout, outstr, outstrlen);
+            ssh2_pkt_send_noqueue(ssh, s->pktout);
+
+	    hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
+
+            sfree(kstr2);
+            sfree(kstr1);
+            sfree(outstr);
+        }
+
+        ssh_rsakex_freekey(s->rsakey);
+
+        crWaitUntil(pktin);
+        if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
+            sfree(s->rsakeydata);
+            bombout(("expected signature packet from server"));
+            crStop(0);
+        }
+
+        ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
+
+        sfree(s->rsakeydata);
+    }
+
+    hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
+    assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
+    ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
+
     ssh->kex_ctx = NULL;
 
 #if 0
     debug(("Exchange hash is:\n"));
-    dmemdump(s->exchange_hash, 20);
+    dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
 #endif
 
-    s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
     if (!s->hkey ||
 	!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
-				 (char *)s->exchange_hash, 20)) {
+				 (char *)s->exchange_hash,
+				 ssh->kex->hash->hlen)) {
 	bombout(("Server's host key did not match the signature supplied"));
 	crStop(0);
     }
@@ -5529,8 +5825,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
     }
     ssh_set_frozen(ssh, 0);
     if (s->dlgret == 0) {
-        ssh->close_expected = TRUE;
-        ssh_closing((Plug)ssh, NULL, 0, 0);
+	ssh_disconnect(ssh, "User aborted at host key verification", NULL,
+		       0, TRUE);
         crStop(0);
     }
     if (!s->got_session_id) {     /* don't bother logging this in rekeys */
@@ -5547,8 +5843,11 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
      * authentication.
      */
     if (!s->got_session_id) {
+	assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
 	memcpy(ssh->v2_session_id, s->exchange_hash,
 	       sizeof(s->exchange_hash));
+	ssh->v2_session_id_len = ssh->kex->hash->hlen;
+	assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
 	s->got_session_id = TRUE;
     }
 
@@ -5583,13 +5882,21 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
      * hash from the _first_ key exchange.
      */
     {
-	unsigned char keyspace[40];
-	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
+	unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
+	assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
+	ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
+	assert((ssh->cscipher->keylen+7) / 8 <=
+	       ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
 	ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
-	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
+	ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
+	assert(ssh->cscipher->blksize <=
+	       ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
 	ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
-	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
+	ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
+	assert(ssh->csmac->len <=
+	       ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
 	ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
+	memset(keyspace, 0, sizeof(keyspace));
     }
 
     logeventf(ssh, "Initialised %.200s client->server encryption",
@@ -5641,13 +5948,21 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
      * hash from the _first_ key exchange.
      */
     {
-	unsigned char keyspace[40];
-	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
+	unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
+	assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
+	ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
+	assert((ssh->sccipher->keylen+7) / 8 <=
+	       ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
 	ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
-	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
+	ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
+	assert(ssh->sccipher->blksize <=
+	       ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
 	ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
-	ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
+	ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
+	assert(ssh->scmac->len <=
+	       ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
 	ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
+	memset(keyspace, 0, sizeof(keyspace));
     }
     logeventf(ssh, "Initialised %.200s server->client encryption",
 	      ssh->sccipher->text_name);
@@ -5658,14 +5973,9 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
 		  ssh->sccomp->text_name);
 
     /*
-     * Free key exchange data.
+     * Free shared secret.
      */
-    freebn(s->f);
     freebn(s->K);
-    if (ssh->kex == &ssh_diffiehellman_gex) {
-	freebn(s->g);
-	freebn(s->p);
-    }
 
     /*
      * Key exchange is over. Loop straight back round if we have a
@@ -5696,7 +6006,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
      * it would only confuse the layer above.
      */
     if (s->activated_authconn) {
-	crReturn(1);
+	crReturn(0);
     }
     s->activated_authconn = TRUE;
 
@@ -5892,7 +6202,8 @@ static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
 	  case CHAN_AGENT:
 	    while (length > 0) {
 		if (c->u.a.lensofar < 4) {
-		    unsigned int l = min(4 - c->u.a.lensofar, length);
+		    unsigned int l = min(4 - c->u.a.lensofar,
+					 (unsigned)length);
 		    memcpy(c->u.a.msglen + c->u.a.lensofar,
 			   data, l);
 		    data += l;
@@ -5909,7 +6220,7 @@ static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
 		if (c->u.a.lensofar >= 4 && length > 0) {
 		    unsigned int l =
 			min(c->u.a.totallen - c->u.a.lensofar,
-			    length);
+			    (unsigned)length);
 		    memcpy(c->u.a.message + c->u.a.lensofar,
 			   data, l);
 		    data += l;
@@ -6011,8 +6322,6 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
      * not running in -N mode.)
      */
     if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
-	logevent("All channels closed. Disconnecting");
-#if 0
 	/*
 	 * We used to send SSH_MSG_DISCONNECT here,
 	 * because I'd believed that _every_ conforming
@@ -6024,14 +6333,7 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
 	 * this is more polite than sending a
 	 * DISCONNECT. So now we don't.
 	 */
-	s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
-	ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
-	ssh2_pkt_addstring(s->pktout, "All open channels closed");
-	ssh2_pkt_addstring(s->pktout, "en");	/* language tag */
-	ssh2_pkt_send_noqueue(ssh, s->pktout);
-#endif
-	ssh->close_expected = TRUE;
-	ssh_closing((Plug)ssh, NULL, 0, 0);
+	ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
     }
 }
 
@@ -6118,18 +6420,10 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
      */
     c = find234(ssh->channels, &localid, ssh_channelfind);
     if (!c) {
-	char buf[80];
-	sprintf(buf, "Received channel request for nonexistent"
-		" channel %d", localid);
-	logevent(buf);
-	pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
-	ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
-	ssh2_pkt_addstring(pktout, buf);
-	ssh2_pkt_addstring(pktout, "en");	/* language tag */
-	ssh2_pkt_send_noqueue(ssh, pktout);
-	connection_fatal(ssh->frontend, "%s", buf);
-	ssh->close_expected = TRUE;
-	ssh_closing((Plug)ssh, NULL, 0, 0);
+	char *buf = dupprintf("Received channel request for nonexistent"
+			      " channel %d", localid);
+	ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
+	sfree(buf);
 	return;
     }
 
@@ -6195,11 +6489,13 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
 			is_plausible = FALSE;
 		}
 	    }
+	    ssh->exitcode = 128;       /* means `unknown signal' */
 	    if (is_plausible) {
 		if (is_int) {
 		    /* Old non-standard OpenSSH. */
 		    int signum = ssh_pkt_getuint32(pktin);
 		    fmt_sig = dupprintf(" %d", signum);
+		    ssh->exitcode = 128 + signum;
 		} else {
 		    /* As per the drafts. */
 		    char *sig;
@@ -6211,6 +6507,60 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
 			fmt_sig = dupprintf(" \"%.*s\"",
 					    siglen, sig);
 		    }
+
+		    /*
+		     * Really hideous method of translating the
+		     * signal description back into a locally
+		     * meaningful number.
+		     */
+
+		    if (0)
+			;
+#define TRANSLATE_SIGNAL(s) \
+    else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
+        ssh->exitcode = 128 + SIG ## s
+#ifdef SIGABRT
+		    TRANSLATE_SIGNAL(ABRT);
+#endif
+#ifdef SIGALRM
+		    TRANSLATE_SIGNAL(ALRM);
+#endif
+#ifdef SIGFPE
+		    TRANSLATE_SIGNAL(FPE);
+#endif
+#ifdef SIGHUP
+		    TRANSLATE_SIGNAL(HUP);
+#endif
+#ifdef SIGILL
+		    TRANSLATE_SIGNAL(ILL);
+#endif
+#ifdef SIGINT
+		    TRANSLATE_SIGNAL(INT);
+#endif
+#ifdef SIGKILL
+		    TRANSLATE_SIGNAL(KILL);
+#endif
+#ifdef SIGPIPE
+		    TRANSLATE_SIGNAL(PIPE);
+#endif
+#ifdef SIGQUIT
+		    TRANSLATE_SIGNAL(QUIT);
+#endif
+#ifdef SIGSEGV
+		    TRANSLATE_SIGNAL(SEGV);
+#endif
+#ifdef SIGTERM
+		    TRANSLATE_SIGNAL(TERM);
+#endif
+#ifdef SIGUSR1
+		    TRANSLATE_SIGNAL(USR1);
+#endif
+#ifdef SIGUSR2
+		    TRANSLATE_SIGNAL(USR2);
+#endif
+#undef TRANSLATE_SIGNAL
+		    else
+			ssh->exitcode = 128;
 		}
 		core = ssh2_pkt_getbool(pktin);
 		ssh_pkt_getstring(pktin, &msg, &msglen);
@@ -6339,7 +6689,7 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
 	    }
 	}
     } else if (typelen == 22 &&
-	       !memcmp(type, "auth-agent@openssh.com", 3)) {
+	       !memcmp(type, "auth-agent@openssh.com", 22)) {
 	if (!ssh->agentfwd_enabled)
 	    error = "Agent forwarding is not enabled";
 	else {
@@ -6378,6 +6728,21 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
     }
 }
 
+/*
+ * Buffer banner messages for later display at some convenient point.
+ */
+static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
+{
+    /* Arbitrary limit to prevent unbounded inflation of buffer */
+    if (bufchain_size(&ssh->banner) <= 131072) {
+	char *banner = NULL;
+	int size = 0;
+	ssh_pkt_getstring(pktin, &banner, &size);
+	if (banner)
+	    bufchain_add(&ssh->banner, banner, size);
+    }
+}
+
 /* Helper function to deal with sending tty modes for "pty-req" */
 static void ssh2_send_ttymode(void *data, char *mode, char *val)
 {
@@ -6406,11 +6771,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 {
     struct do_ssh2_authconn_state {
 	enum {
-	    AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
-		AUTH_PASSWORD,
-		AUTH_KEYBOARD_INTERACTIVE
-	} method;
-	enum {
 	    AUTH_TYPE_NONE,
 		AUTH_TYPE_PUBLICKEY,
 		AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
@@ -6419,21 +6779,25 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 		AUTH_TYPE_KEYBOARD_INTERACTIVE,
 		AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
 	} type;
+	int done_service_req;
 	int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
-	int tried_pubkey_config, tried_agent;
-	int kbd_inter_running, kbd_inter_refused;
+	int tried_pubkey_config, done_agent;
+	int kbd_inter_refused;
 	int we_are_in;
-	int num_prompts, curr_prompt, echo;
+	prompts_t *cur_prompt;
+	int num_prompts;
 	char username[100];
+	char *password;
 	int got_username;
-	char pwprompt[512];
-	char password[100];
 	void *publickey_blob;
 	int publickey_bloblen;
-	unsigned char request[5], *response, *p;
-	int responselen;
+	int publickey_encrypted;
+	char *publickey_algorithm;
+	char *publickey_comment;
+	unsigned char agent_request[5], *agent_response, *agentp;
+	int agent_responselen;
+	unsigned char *pkblob_in_agent;
 	int keyi, nkeys;
-	int authed;
 	char *pkblob, *alg, *commentp;
 	int pklen, alglen, commentlen;
 	int siglen, retlen, len;
@@ -6446,16 +6810,153 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 
     crBegin(ssh->do_ssh2_authconn_crstate);
 
+    s->done_service_req = FALSE;
+    s->we_are_in = FALSE;
+    if (!ssh->cfg.ssh_no_userauth) {
+	/*
+	 * Request userauth protocol, and await a response to it.
+	 */
+	s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
+	ssh2_pkt_addstring(s->pktout, "ssh-userauth");
+	ssh2_pkt_send(ssh, s->pktout);
+	crWaitUntilV(pktin);
+	if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
+	    s->done_service_req = TRUE;
+    }
+    if (!s->done_service_req) {
+	/*
+	 * Request connection protocol directly, without authentication.
+	 */
+	s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
+	ssh2_pkt_addstring(s->pktout, "ssh-connection");
+	ssh2_pkt_send(ssh, s->pktout);
+	crWaitUntilV(pktin);
+	if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
+	    s->we_are_in = TRUE; /* no auth required */
+	} else {
+	    bombout(("Server refused service request"));
+	    crStopV;
+	}
+    }
+
+    /* Arrange to be able to deal with any BANNERs that come in.
+     * (We do this now as packets may come in during the next bit.) */
+    bufchain_init(&ssh->banner);
+    ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
+	ssh2_msg_userauth_banner;
+
     /*
-     * Request userauth protocol, and await a response to it.
+     * Misc one-time setup for authentication.
      */
-    s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
-    ssh2_pkt_addstring(s->pktout, "ssh-userauth");
-    ssh2_pkt_send(ssh, s->pktout);
-    crWaitUntilV(pktin);
-    if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
-	bombout(("Server refused user authentication protocol"));
-	crStopV;
+    s->publickey_blob = NULL;
+    if (!s->we_are_in) {
+
+	/*
+	 * Load the public half of any configured public key file
+	 * for later use.
+	 */
+	if (!filename_is_null(ssh->cfg.keyfile)) {
+	    int keytype;
+	    logeventf(ssh, "Reading private key file \"%.150s\"",
+		      filename_to_str(&ssh->cfg.keyfile));
+	    keytype = key_type(&ssh->cfg.keyfile);
+	    if (keytype == SSH_KEYTYPE_SSH2) {
+		const char *error;
+		s->publickey_blob =
+		    ssh2_userkey_loadpub(&ssh->cfg.keyfile,
+					 &s->publickey_algorithm,
+					 &s->publickey_bloblen, 
+					 &s->publickey_comment, &error);
+		if (s->publickey_blob) {
+		    s->publickey_encrypted =
+			ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
+		} else {
+		    char *msgbuf;
+		    logeventf(ssh, "Unable to load private key (%s)", 
+			      error);
+		    msgbuf = dupprintf("Unable to load private key file "
+				       "\"%.150s\" (%s)\r\n",
+				       filename_to_str(&ssh->cfg.keyfile),
+				       error);
+		    c_write_str(ssh, msgbuf);
+		    sfree(msgbuf);
+		}
+	    } else {
+		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",
+				   filename_to_str(&ssh->cfg.keyfile),
+				   key_type_to_str(keytype));
+		c_write_str(ssh, msgbuf);
+		sfree(msgbuf);
+		s->publickey_blob = NULL;
+	    }
+	}
+
+	/*
+	 * Find out about any keys Pageant has (but if there's a
+	 * public key configured, filter out all others).
+	 */
+	s->nkeys = 0;
+	s->agent_response = NULL;
+	s->pkblob_in_agent = NULL;
+	if (ssh->cfg.tryagent && agent_exists()) {
+
+	    void *r;
+
+	    logevent("Pageant is running. Requesting keys.");
+
+	    /* Request the keys held by the agent. */
+	    PUT_32BIT(s->agent_request, 1);
+	    s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
+	    if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
+			     ssh_agent_callback, ssh)) {
+		do {
+		    crReturnV;
+		    if (pktin) {
+			bombout(("Unexpected data from server while"
+				 " waiting for agent response"));
+			crStopV;
+		    }
+		} while (pktin || inlen > 0);
+		r = ssh->agent_response;
+		s->agent_responselen = ssh->agent_response_len;
+	    }
+	    s->agent_response = (unsigned char *) r;
+	    if (s->agent_response && s->agent_responselen >= 5 &&
+		s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
+		int keyi;
+		unsigned char *p;
+		p = s->agent_response + 5;
+		s->nkeys = GET_32BIT(p);
+		p += 4;
+		logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
+		if (s->publickey_blob) {
+		    /* See if configured key is in agent. */
+		    for (keyi = 0; keyi < s->nkeys; keyi++) {
+			s->pklen = GET_32BIT(p);
+			if (s->pklen == s->publickey_bloblen &&
+			    !memcmp(p+4, s->publickey_blob,
+				    s->publickey_bloblen)) {
+			    logeventf(ssh, "Pageant key #%d matches "
+				      "configured key file", keyi);
+			    s->keyi = keyi;
+			    s->pkblob_in_agent = p;
+			    break;
+			}
+			p += 4 + s->pklen;
+			p += GET_32BIT(p) + 4; /* comment */
+		    }
+		    if (!s->pkblob_in_agent) {
+			logevent("Configured key file not in Pageant");
+			s->nkeys = 0;
+		    }
+		}
+	    }
+	}
+
     }
 
     /*
@@ -6484,7 +6985,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
      */
     s->username[0] = '\0';
     s->got_username = FALSE;
-    do {
+    while (!s->we_are_in) {
 	/*
 	 * Get a username.
 	 */
@@ -6495,32 +6996,31 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 	     * it again.
 	     */
 	} else if (!*ssh->cfg.username) {
-	    if (ssh_get_line && !ssh_getline_pw_only) {
-		if (!ssh_get_line("login as: ",
-				  s->username, sizeof(s->username), FALSE)) {
-		    /*
-		     * get_line failed to get a username.
-		     * Terminate.
-		     */
-		    logevent("No username provided. Abandoning session.");
-		    ssh->close_expected = TRUE;
-                    ssh_closing((Plug)ssh, NULL, 0, 0);
-		    crStopV;
-		}
-	    } else {
-		int ret;	       /* need not be saved across crReturn */
-		c_write_str(ssh, "login as: ");
+	    int ret; /* need not be kept over crReturn */
+	    s->cur_prompt = new_prompts(ssh->frontend);
+	    s->cur_prompt->to_server = TRUE;
+	    s->cur_prompt->name = dupstr("SSH login name");
+	    add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
+		       lenof(s->username)); 
+	    ret = get_userpass_input(s->cur_prompt, NULL, 0);
+	    while (ret < 0) {
 		ssh->send_ok = 1;
-		setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
-		do {
-		    crWaitUntilV(!pktin);
-		    ret = process_userpass_input(ssh, in, inlen);
-		} while (ret == 0);
-		if (ret < 0)
-		    cleanup_exit(0);
-		c_write_str(ssh, "\r\n");
+		crWaitUntilV(!pktin);
+		ret = get_userpass_input(s->cur_prompt, in, inlen);
+		ssh->send_ok = 0;
+	    }
+	    if (!ret) {
+		/*
+		 * get_userpass_input() failed to get a username.
+		 * Terminate.
+		 */
+		free_prompts(s->cur_prompt);
+		ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
+		crStopV;
 	    }
-	    s->username[strcspn(s->username, "\n\r")] = '\0';
+	    memcpy(s->username, s->cur_prompt->prompts[0]->result,
+		   lenof(s->username));
+	    free_prompts(s->cur_prompt);
 	} else {
 	    char *stuff;
 	    strncpy(s->username, ssh->cfg.username, sizeof(s->username));
@@ -6550,33 +7050,18 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 	s->we_are_in = FALSE;
 
 	s->tried_pubkey_config = FALSE;
-	s->tried_agent = FALSE;
-	s->kbd_inter_running = FALSE;
 	s->kbd_inter_refused = FALSE;
-	/* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
-	if (!filename_is_null(ssh->cfg.keyfile)) {
-	    int keytype;
-	    logeventf(ssh, "Reading private key file \"%.150s\"",
-		      filename_to_str(&ssh->cfg.keyfile));
-	    keytype = key_type(&ssh->cfg.keyfile);
-	    if (keytype == SSH_KEYTYPE_SSH2) {
-		s->publickey_blob =
-		    ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
-					 &s->publickey_bloblen, NULL);
+
+	/* Reset agent request state. */
+	s->done_agent = FALSE;
+	if (s->agent_response) {
+	    if (s->pkblob_in_agent) {
+		s->agentp = s->pkblob_in_agent;
 	    } else {
-		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",
-				   filename_to_str(&ssh->cfg.keyfile),
-				   key_type_to_str(keytype));
-		c_write_str(ssh, msgbuf);
-		sfree(msgbuf);
-		s->publickey_blob = NULL;
+		s->agentp = s->agent_response + 5 + 4;
+		s->keyi = 0;
 	    }
-	} else
-	    s->publickey_blob = NULL;
+	}
 
 	while (1) {
 	    /*
@@ -6584,9 +7069,14 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 	     */
 	    if (!s->gotit)
 		crWaitUntilV(pktin);
-	    while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
-		char *banner;
-		int size;
+	    /*
+	     * Now is a convenient point to spew any banner material
+	     * that we've accumulated. (This should ensure that when
+	     * we exit the auth loop, we haven't any left to deal
+	     * with.)
+	     */
+	    {
+		int size = bufchain_size(&ssh->banner);
 		/*
 		 * Don't show the banner if we're operating in
 		 * non-verbose non-interactive mode. (It's probably
@@ -6595,12 +7085,13 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 		 * the banner will screw up processing on the
 		 * output of (say) plink.)
 		 */
-		if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
-		    ssh_pkt_getstring(pktin, &banner, &size);
-		    if (banner)
-			c_write_untrusted(ssh, banner, size);
+		if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
+		    char *banner = snewn(size, char);
+		    bufchain_fetch(&ssh->banner, banner, size);
+		    c_write_untrusted(ssh, banner, size);
+		    sfree(banner);
 		}
-		crWaitUntilV(pktin);
+		bufchain_clear(&ssh->banner);
 	    }
 	    if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
 		logevent("Access granted");
@@ -6608,24 +7099,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 		break;
 	    }
 
-	    if (s->kbd_inter_running &&
-		pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
-		/*
-		 * This is either a further set-of-prompts packet
-		 * in keyboard-interactive authentication, or it's
-		 * the same one and we came back here with `gotit'
-		 * set. In the former case, we must reset the
-		 * curr_prompt variable.
-		 */
-		if (!s->gotit)
-		    s->curr_prompt = 0;
-	    } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
-		/* FIXME: perhaps we should support this? */
-		bombout(("PASSWD_CHANGEREQ not yet supported"));
-		crStopV;
-	    } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
-		bombout(("Strange packet received during authentication: type %d",
-			 pktin->type));
+	    if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
+		bombout(("Strange packet received during authentication: "
+			 "type %d", pktin->type));
 		crStopV;
 	    }
 
@@ -6640,7 +7116,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 		char *methods;
 		int methlen;
 		ssh_pkt_getstring(pktin, &methods, &methlen);
-		s->kbd_inter_running = FALSE;
 		if (!ssh2_pkt_getbool(pktin)) {
 		    /*
 		     * We have received an unequivocal Access
@@ -6697,418 +7172,275 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 		    in_commasep_string("keyboard-interactive", methods, methlen);
 	    }
 
-	    s->method = 0;
 	    ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
-	    s->need_pw = FALSE;
 
-	    /*
-	     * Most password/passphrase prompts will be
-	     * non-echoing, so we set this to 0 by default.
-	     * Exception is that some keyboard-interactive prompts
-	     * can be echoing, in which case we'll set this to 1.
-	     */
-	    s->echo = 0;
+	    if (s->can_pubkey && !s->done_agent && s->nkeys) {
 
-	    if (!s->method && s->can_pubkey &&
-		agent_exists() && !s->tried_agent) {
 		/*
-		 * Attempt public-key authentication using Pageant.
+		 * Attempt public-key authentication using a key from Pageant.
 		 */
-		void *r;
-		s->authed = FALSE;
 
 		ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
 		ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
 
-		s->tried_agent = TRUE;
+		logeventf(ssh, "Trying Pageant key #%d", s->keyi);
+
+		/* Unpack key from agent response */
+		s->pklen = GET_32BIT(s->agentp);
+		s->agentp += 4;
+		s->pkblob = (char *)s->agentp;
+		s->agentp += s->pklen;
+		s->alglen = GET_32BIT(s->pkblob);
+		s->alg = s->pkblob + 4;
+		s->commentlen = GET_32BIT(s->agentp);
+		s->agentp += 4;
+		s->commentp = (char *)s->agentp;
+		s->agentp += s->commentlen;
+		/* s->agentp now points at next key, if any */
+
+		/* See if server will accept it */
+		s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+		ssh2_pkt_addstring(s->pktout, s->username);
+		ssh2_pkt_addstring(s->pktout, "ssh-connection");
+						    /* service requested */
+		ssh2_pkt_addstring(s->pktout, "publickey");
+						    /* method */
+		ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
+		ssh2_pkt_addstring_start(s->pktout);
+		ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
+		ssh2_pkt_addstring_start(s->pktout);
+		ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
+		ssh2_pkt_send(ssh, s->pktout);
+		s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
 
-		logevent("Pageant is running. Requesting keys.");
+		crWaitUntilV(pktin);
+		if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
 
-		/* Request the keys held by the agent. */
-		PUT_32BIT(s->request, 1);
-		s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
-		if (!agent_query(s->request, 5, &r, &s->responselen,
-				 ssh_agent_callback, ssh)) {
-		    do {
-			crReturnV;
-			if (pktin) {
-			    bombout(("Unexpected data from server while"
-				     " waiting for agent response"));
-			    crStopV;
-			}
-		    } while (pktin || inlen > 0);
-		    r = ssh->agent_response;
-		    s->responselen = ssh->agent_response_len;
-		}
-		s->response = (unsigned char *) r;
-		if (s->response && s->responselen >= 5 &&
-		    s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
-		    s->p = s->response + 5;
-		    s->nkeys = GET_32BIT(s->p);
-		    s->p += 4;
-		    logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
-		    for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
-			void *vret;
+		    /* Offer of key refused. */
+		    s->gotit = TRUE;
 
-			logeventf(ssh, "Trying Pageant key #%d", s->keyi);
-			s->pklen = GET_32BIT(s->p);
-			s->p += 4;
-			if (s->publickey_blob &&
-			    s->pklen == s->publickey_bloblen &&
-			    !memcmp(s->p, s->publickey_blob,
-				    s->publickey_bloblen)) {
-			    logevent("This key matches configured key file");
-			    s->tried_pubkey_config = 1;
-			}
-			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 = (char *)s->p;
-			s->p += s->commentlen;
-			s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
-			ssh2_pkt_addstring(s->pktout, s->username);
-			ssh2_pkt_addstring(s->pktout, "ssh-connection");	/* service requested */
-			ssh2_pkt_addstring(s->pktout, "publickey");	/* method */
-			ssh2_pkt_addbool(s->pktout, FALSE);	/* no signature included */
-			ssh2_pkt_addstring_start(s->pktout);
-			ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
-			ssh2_pkt_addstring_start(s->pktout);
-			ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
-			ssh2_pkt_send(ssh, s->pktout);
-
-			crWaitUntilV(pktin);
-			if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
-			    logevent("Key refused");
-			    continue;
-			}
+		} else {
+		    
+		    void *vret;
 
-			if (flags & FLAG_VERBOSE) {
-			    c_write_str(ssh, "Authenticating with "
-					"public key \"");
-			    c_write(ssh, s->commentp, s->commentlen);
-			    c_write_str(ssh, "\" from agent\r\n");
-			}
+		    if (flags & FLAG_VERBOSE) {
+			c_write_str(ssh, "Authenticating with "
+				    "public key \"");
+			c_write(ssh, s->commentp, s->commentlen);
+			c_write_str(ssh, "\" from agent\r\n");
+		    }
 
-			/*
-			 * Server is willing to accept the key.
-			 * Construct a SIGN_REQUEST.
-			 */
-			s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
-			ssh2_pkt_addstring(s->pktout, s->username);
-			ssh2_pkt_addstring(s->pktout, "ssh-connection");	/* service requested */
-			ssh2_pkt_addstring(s->pktout, "publickey");	/* method */
-			ssh2_pkt_addbool(s->pktout, TRUE);
-			ssh2_pkt_addstring_start(s->pktout);
-			ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
-			ssh2_pkt_addstring_start(s->pktout);
-			ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
-
-			s->siglen = s->pktout->length - 5 + 4 + 20;
-                        if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
-                            s->siglen -= 4;
-			s->len = 1;       /* message type */
-			s->len += 4 + s->pklen;	/* key blob */
-			s->len += 4 + s->siglen;	/* data to sign */
-			s->len += 4;      /* flags */
-			s->agentreq = snewn(4 + s->len, char);
-			PUT_32BIT(s->agentreq, s->len);
-			s->q = s->agentreq + 4;
-			*s->q++ = SSH2_AGENTC_SIGN_REQUEST;
-			PUT_32BIT(s->q, s->pklen);
-			s->q += 4;
-			memcpy(s->q, s->pkblob, s->pklen);
-			s->q += s->pklen;
-			PUT_32BIT(s->q, s->siglen);
+		    /*
+		     * Server is willing to accept the key.
+		     * Construct a SIGN_REQUEST.
+		     */
+		    s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+		    ssh2_pkt_addstring(s->pktout, s->username);
+		    ssh2_pkt_addstring(s->pktout, "ssh-connection");
+							/* service requested */
+		    ssh2_pkt_addstring(s->pktout, "publickey");
+							/* method */
+		    ssh2_pkt_addbool(s->pktout, TRUE);  /* signature included */
+		    ssh2_pkt_addstring_start(s->pktout);
+		    ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
+		    ssh2_pkt_addstring_start(s->pktout);
+		    ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
+
+		    /* Ask agent for signature. */
+		    s->siglen = s->pktout->length - 5 + 4 +
+			ssh->v2_session_id_len;
+		    if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
+			s->siglen -= 4;
+		    s->len = 1;       /* message type */
+		    s->len += 4 + s->pklen;	/* key blob */
+		    s->len += 4 + s->siglen;	/* data to sign */
+		    s->len += 4;      /* flags */
+		    s->agentreq = snewn(4 + s->len, char);
+		    PUT_32BIT(s->agentreq, s->len);
+		    s->q = s->agentreq + 4;
+		    *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
+		    PUT_32BIT(s->q, s->pklen);
+		    s->q += 4;
+		    memcpy(s->q, s->pkblob, s->pklen);
+		    s->q += s->pklen;
+		    PUT_32BIT(s->q, s->siglen);
+		    s->q += 4;
+		    /* Now the data to be signed... */
+		    if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
+			PUT_32BIT(s->q, ssh->v2_session_id_len);
 			s->q += 4;
-			/* Now the data to be signed... */
-                        if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
-                            PUT_32BIT(s->q, 20);
-                            s->q += 4;
-                        }
-			memcpy(s->q, ssh->v2_session_id, 20);
-			s->q += 20;
-			memcpy(s->q, s->pktout->data + 5,
-			       s->pktout->length - 5);
-			s->q += s->pktout->length - 5;
-			/* And finally the (zero) flags word. */
-			PUT_32BIT(s->q, 0);
-			if (!agent_query(s->agentreq, s->len + 4,
-					 &vret, &s->retlen,
-					 ssh_agent_callback, ssh)) {
-			    do {
-				crReturnV;
-				if (pktin) {
-				    bombout(("Unexpected data from server"
-					     " while waiting for agent"
-					     " response"));
-				    crStopV;
-				}
-			    } while (pktin || inlen > 0);
-			    vret = ssh->agent_response;
-			    s->retlen = ssh->agent_response_len;
-			}
-			s->ret = vret;
-			sfree(s->agentreq);
-			if (s->ret) {
-			    if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
-				logevent("Sending Pageant's response");
-				ssh2_add_sigblob(ssh, s->pktout,
-						 s->pkblob, s->pklen,
-						 s->ret + 9,
-						 GET_32BIT(s->ret + 5));
-				ssh2_pkt_send(ssh, s->pktout);
-				s->authed = TRUE;
-				break;
-			    } else {
-				logevent
-				    ("Pageant failed to answer challenge");
-				sfree(s->ret);
+		    }
+		    memcpy(s->q, ssh->v2_session_id,
+			   ssh->v2_session_id_len);
+		    s->q += ssh->v2_session_id_len;
+		    memcpy(s->q, s->pktout->data + 5,
+			   s->pktout->length - 5);
+		    s->q += s->pktout->length - 5;
+		    /* And finally the (zero) flags word. */
+		    PUT_32BIT(s->q, 0);
+		    if (!agent_query(s->agentreq, s->len + 4,
+				     &vret, &s->retlen,
+				     ssh_agent_callback, ssh)) {
+			do {
+			    crReturnV;
+			    if (pktin) {
+				bombout(("Unexpected data from server"
+					 " while waiting for agent"
+					 " response"));
+				crStopV;
 			    }
+			} while (pktin || inlen > 0);
+			vret = ssh->agent_response;
+			s->retlen = ssh->agent_response_len;
+		    }
+		    s->ret = vret;
+		    sfree(s->agentreq);
+		    if (s->ret) {
+			if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
+			    logevent("Sending Pageant's response");
+			    ssh2_add_sigblob(ssh, s->pktout,
+					     s->pkblob, s->pklen,
+					     s->ret + 9,
+					     GET_32BIT(s->ret + 5));
+			    ssh2_pkt_send(ssh, s->pktout);
+			    s->type = AUTH_TYPE_PUBLICKEY;
+			} else {
+			    /* FIXME: less drastic response */
+			    bombout(("Pageant failed to answer challenge"));
+			    crStopV;
 			}
 		    }
-		    if (s->authed)
-			continue;
 		}
-		sfree(s->response);
-	    }
 
-	    if (!s->method && s->can_pubkey && s->publickey_blob
-		&& !s->tried_pubkey_config) {
-		unsigned char *pub_blob;
-		char *algorithm, *comment;
-		int pub_blob_len;
+		/* Do we have any keys left to try? */
+		if (s->pkblob_in_agent) {
+		    s->done_agent = TRUE;
+		    s->tried_pubkey_config = TRUE;
+		} else {
+		    s->keyi++;
+		    if (s->keyi >= s->nkeys)
+			s->done_agent = TRUE;
+		}
 
-		s->tried_pubkey_config = TRUE;
+	    } else if (s->can_pubkey && s->publickey_blob &&
+		       !s->tried_pubkey_config) {
+
+		struct ssh2_userkey *key;   /* not live over crReturn */
+		char *passphrase;	    /* not live over crReturn */
 
 		ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
 		ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
 
+		s->tried_pubkey_config = TRUE;
+
 		/*
 		 * Try the public key supplied in the configuration.
 		 *
 		 * First, offer the public blob to see if the server is
 		 * willing to accept it.
 		 */
-		pub_blob =
-		    (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
-							  &algorithm,
-							  &pub_blob_len,
-							  NULL);
-		if (pub_blob) {
-		    s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
-		    ssh2_pkt_addstring(s->pktout, s->username);
-		    ssh2_pkt_addstring(s->pktout, "ssh-connection");	/* service requested */
-		    ssh2_pkt_addstring(s->pktout, "publickey");	/* method */
-		    ssh2_pkt_addbool(s->pktout, FALSE);	/* no signature included */
-		    ssh2_pkt_addstring(s->pktout, algorithm);
-		    ssh2_pkt_addstring_start(s->pktout);
-		    ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
-					    pub_blob_len);
-		    ssh2_pkt_send(ssh, s->pktout);
-		    logevent("Offered public key");
-
-		    crWaitUntilV(pktin);
-		    if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
-			s->gotit = TRUE;
-			s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
-			continue;      /* key refused; give up on it */
-		    }
-
-		    logevent("Offer of public key accepted");
-		    /*
-		     * Actually attempt a serious authentication using
-		     * the key.
-		     */
-		    if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
-			sprintf(s->pwprompt,
-				"Passphrase for key \"%.100s\": ",
-				comment);
-			s->need_pw = TRUE;
-		    } else {
-			s->need_pw = FALSE;
-		    }
-		    if (flags & FLAG_VERBOSE) {
-			c_write_str(ssh, "Authenticating with public key \"");
-			c_write_str(ssh, comment);
-			c_write_str(ssh, "\"\r\n");
-		    }
-		    s->method = AUTH_PUBLICKEY_FILE;
-		}
-	    }
-
-	    if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
-		!s->kbd_inter_running) {
-		s->method = AUTH_KEYBOARD_INTERACTIVE;
-		s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
-
-		ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
-		ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
-
 		s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
 		ssh2_pkt_addstring(s->pktout, s->username);
-		ssh2_pkt_addstring(s->pktout, "ssh-connection");	/* service requested */
-		ssh2_pkt_addstring(s->pktout, "keyboard-interactive");	/* method */
-		ssh2_pkt_addstring(s->pktout, ""); /* lang */
-		ssh2_pkt_addstring(s->pktout, "");
+		ssh2_pkt_addstring(s->pktout, "ssh-connection");
+						/* service requested */
+		ssh2_pkt_addstring(s->pktout, "publickey");	/* method */
+		ssh2_pkt_addbool(s->pktout, FALSE);
+						/* no signature included */
+		ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
+		ssh2_pkt_addstring_start(s->pktout);
+		ssh2_pkt_addstring_data(s->pktout,
+					(char *)s->publickey_blob,
+					s->publickey_bloblen);
 		ssh2_pkt_send(ssh, s->pktout);
+		logevent("Offered public key");
 
 		crWaitUntilV(pktin);
-		if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
-		    if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
-			s->gotit = TRUE;
-		    logevent("Keyboard-interactive authentication refused");
-		    s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
-		    s->kbd_inter_refused = TRUE; /* don't try it again */
-		    continue;
-		}
-
-		c_write_str(ssh, "Using keyboard-interactive authentication.\r\n");
-		s->kbd_inter_running = TRUE;
-		s->curr_prompt = 0;
-	    }
-
-	    if (s->kbd_inter_running) {
-		s->method = AUTH_KEYBOARD_INTERACTIVE;
-		s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
-
-		ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
-		ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
-
-		if (s->curr_prompt == 0) {
-		    /*
-		     * We've got a fresh USERAUTH_INFO_REQUEST.
-		     * Display header data, and start going through
-		     * the prompts.
-		     */
-		    char *name, *inst, *lang;
-		    int name_len, inst_len, lang_len;
-
-		    ssh_pkt_getstring(pktin, &name, &name_len);
-		    ssh_pkt_getstring(pktin, &inst, &inst_len);
-		    ssh_pkt_getstring(pktin, &lang, &lang_len);
-		    if (name_len > 0) {
-			c_write_untrusted(ssh, name, name_len);
-			c_write_str(ssh, "\r\n");
-		    }
-		    if (inst_len > 0) {
-			c_write_untrusted(ssh, inst, inst_len);
-			c_write_str(ssh, "\r\n");
-		    }
-		    s->num_prompts = ssh_pkt_getuint32(pktin);
+		if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
+		    /* Key refused. Give up. */
+		    s->gotit = TRUE; /* reconsider message next loop */
+		    s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
+		    continue; /* process this new message */
 		}
+		logevent("Offer of public key accepted");
 
 		/*
-		 * If there are prompts remaining in the packet,
-		 * display one and get a response.
+		 * Actually attempt a serious authentication using
+		 * the key.
 		 */
-		if (s->curr_prompt < s->num_prompts) {
-		    char *prompt;
-		    int prompt_len;
-
-		    ssh_pkt_getstring(pktin, &prompt, &prompt_len);
-		    if (prompt_len > 0) {
-			static const char trunc[] = "<prompt truncated>: ";
-			static const int prlen = sizeof(s->pwprompt) -
-						 lenof(trunc);
-			if (prompt_len > prlen) {
-			    memcpy(s->pwprompt, prompt, prlen);
-			    strcpy(s->pwprompt + prlen, trunc);
-			} else {
-			    memcpy(s->pwprompt, prompt, prompt_len);
-			    s->pwprompt[prompt_len] = '\0';
+		if (flags & FLAG_VERBOSE) {
+		    c_write_str(ssh, "Authenticating with public key \"");
+		    c_write_str(ssh, s->publickey_comment);
+		    c_write_str(ssh, "\"\r\n");
+		}
+		key = NULL;
+		while (!key) {
+		    const char *error;  /* not live over crReturn */
+		    if (s->publickey_encrypted) {
+			/*
+			 * Get a passphrase from the user.
+			 */
+			int ret; /* need not be kept over crReturn */
+			s->cur_prompt = new_prompts(ssh->frontend);
+			s->cur_prompt->to_server = FALSE;
+			s->cur_prompt->name = dupstr("SSH key passphrase");
+			add_prompt(s->cur_prompt,
+				   dupprintf("Passphrase for key \"%.100s\": ",
+					     s->publickey_comment),
+				   FALSE, SSH_MAX_PASSWORD_LEN);
+			ret = get_userpass_input(s->cur_prompt, NULL, 0);
+			while (ret < 0) {
+			    ssh->send_ok = 1;
+			    crWaitUntilV(!pktin);
+			    ret = get_userpass_input(s->cur_prompt,
+						     in, inlen);
+			    ssh->send_ok = 0;
+			}
+			if (!ret) {
+			    /* Failed to get a passphrase. Terminate. */
+			    free_prompts(s->cur_prompt);
+			    ssh_disconnect(ssh, NULL,
+					   "Unable to authenticate",
+					   SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
+					   TRUE);
+			    crStopV;
 			}
+			passphrase =
+			    dupstr(s->cur_prompt->prompts[0]->result);
+			free_prompts(s->cur_prompt);
 		    } else {
-			strcpy(s->pwprompt,
-			       "<server failed to send prompt>: ");
+			passphrase = NULL; /* no passphrase needed */
 		    }
-		    s->echo = ssh2_pkt_getbool(pktin);
-		    s->need_pw = TRUE;
-		} else
-		    s->need_pw = FALSE;
-	    }
 
-	    if (!s->method && s->can_passwd) {
-		s->method = AUTH_PASSWORD;
-		ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
-		ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
-		sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
-			ssh->savedhost);
-		s->need_pw = TRUE;
-	    }
-
-	    if (s->need_pw) {
-		if (ssh_get_line) {
-		    if (!ssh_get_line(s->pwprompt, s->password,
-				      sizeof(s->password), TRUE)) {
-			/*
-			 * get_line failed to get a password (for
-			 * example because one was supplied on the
-			 * command line which has already failed to
-			 * work). Terminate.
-			 */
-			s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
-			ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
-			ssh2_pkt_addstring(s->pktout, "No more passwords available"
-					   " to try");
-			ssh2_pkt_addstring(s->pktout, "en");	/* language tag */
-			ssh2_pkt_send_noqueue(ssh, s->pktout);
-			logevent("Unable to authenticate");
-			connection_fatal(ssh->frontend,
-					 "Unable to authenticate");
-			ssh->close_expected = TRUE;
-                        ssh_closing((Plug)ssh, NULL, 0, 0);
-			crStopV;
+		    /*
+		     * Try decrypting the key.
+		     */
+		    key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
+					    &error);
+		    if (passphrase) {
+			/* burn the evidence */
+			memset(passphrase, 0, strlen(passphrase));
+			sfree(passphrase);
+		    }
+		    if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
+			if (passphrase &&
+			    (key == SSH2_WRONG_PASSPHRASE)) {
+			    c_write_str(ssh, "Wrong passphrase\r\n");
+			    key = NULL;
+			    /* and loop again */
+			} else {
+			    c_write_str(ssh, "Unable to load private key (");
+			    c_write_str(ssh, error);
+			    c_write_str(ssh, ")\r\n");
+			    key = NULL;
+			    break; /* try something else */
+			}
 		    }
-		} else {
-		    int ret;	       /* need not be saved across crReturn */
-		    c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
-		    ssh->send_ok = 1;
-
-		    setup_userpass_input(ssh, s->password,
-					 sizeof(s->password), s->echo);
-		    do {
-			crWaitUntilV(!pktin);
-			ret = process_userpass_input(ssh, in, inlen);
-		    } while (ret == 0);
-		    if (ret < 0)
-			cleanup_exit(0);
-		    c_write_str(ssh, "\r\n");
 		}
-	    }
 
-	    if (s->method == AUTH_PUBLICKEY_FILE) {
-		/*
-		 * We have our passphrase. Now try the actual authentication.
-		 */
-		struct ssh2_userkey *key;
-		const char *error = NULL;
-
-		key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
-					&error);
-		if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
-		    if (key == SSH2_WRONG_PASSPHRASE) {
-			c_write_str(ssh, "Wrong passphrase\r\n");
-			s->tried_pubkey_config = FALSE;
-		    } else {
-			c_write_str(ssh, "Unable to load private key (");
-			c_write_str(ssh, error);
-			c_write_str(ssh, ")\r\n");
-			s->tried_pubkey_config = TRUE;
-		    }
-		    /* Send a spurious AUTH_NONE to return to the top. */
-		    s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
-		    ssh2_pkt_addstring(s->pktout, s->username);
-		    ssh2_pkt_addstring(s->pktout, "ssh-connection");	/* service requested */
-		    ssh2_pkt_addstring(s->pktout, "none");	/* method */
-		    ssh2_pkt_send(ssh, s->pktout);
-		    s->type = AUTH_TYPE_NONE;
-		} else {
+		if (key) {
 		    unsigned char *pkblob, *sigblob, *sigdata;
 		    int pkblob_len, sigblob_len, sigdata_len;
-                    int p;
+		    int p;
 
 		    /*
 		     * We have loaded the private key and the server
@@ -7117,13 +7449,18 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 		     */
 		    s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
 		    ssh2_pkt_addstring(s->pktout, s->username);
-		    ssh2_pkt_addstring(s->pktout, "ssh-connection");	/* service requested */
-		    ssh2_pkt_addstring(s->pktout, "publickey");	/* method */
+		    ssh2_pkt_addstring(s->pktout, "ssh-connection");
+						    /* service requested */
+		    ssh2_pkt_addstring(s->pktout, "publickey");
+						    /* method */
 		    ssh2_pkt_addbool(s->pktout, TRUE);
+						    /* signature follows */
 		    ssh2_pkt_addstring(s->pktout, key->alg->name);
-		    pkblob = key->alg->public_blob(key->data, &pkblob_len);
+		    pkblob = key->alg->public_blob(key->data,
+						   &pkblob_len);
 		    ssh2_pkt_addstring_start(s->pktout);
-		    ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
+		    ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
+					    pkblob_len);
 
 		    /*
 		     * The data to be signed is:
@@ -7133,20 +7470,23 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 		     * followed by everything so far placed in the
 		     * outgoing packet.
 		     */
-		    sigdata_len = s->pktout->length - 5 + 4 + 20;
-                    if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
-                        sigdata_len -= 4;
+		    sigdata_len = s->pktout->length - 5 + 4 +
+			ssh->v2_session_id_len;
+		    if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
+			sigdata_len -= 4;
 		    sigdata = snewn(sigdata_len, unsigned char);
-                    p = 0;
-                    if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
-                        PUT_32BIT(sigdata+p, 20);
-                        p += 4;
-                    }
-		    memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
+		    p = 0;
+		    if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
+			PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
+			p += 4;
+		    }
+		    memcpy(sigdata+p, ssh->v2_session_id,
+			   ssh->v2_session_id_len);
+		    p += ssh->v2_session_id_len;
 		    memcpy(sigdata+p, s->pktout->data + 5,
 			   s->pktout->length - 5);
-                    p += s->pktout->length - 5;
-                    assert(p == sigdata_len);
+		    p += s->pktout->length - 5;
+		    assert(p == sigdata_len);
 		    sigblob = key->alg->sign(key->data, (char *)sigdata,
 					     sigdata_len, &sigblob_len);
 		    ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
@@ -7159,8 +7499,196 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 		    s->type = AUTH_TYPE_PUBLICKEY;
 		    key->alg->freekey(key->data);
 		}
-	    } else if (s->method == AUTH_PASSWORD) {
+
+	    } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
+
 		/*
+		 * Keyboard-interactive authentication.
+		 */
+
+		s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
+
+		ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
+		ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
+
+		s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+		ssh2_pkt_addstring(s->pktout, s->username);
+		ssh2_pkt_addstring(s->pktout, "ssh-connection");
+							/* service requested */
+		ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
+							/* method */
+		ssh2_pkt_addstring(s->pktout, "");	/* lang */
+		ssh2_pkt_addstring(s->pktout, "");	/* submethods */
+		ssh2_pkt_send(ssh, s->pktout);
+
+		crWaitUntilV(pktin);
+		if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
+		    /* Server is not willing to do keyboard-interactive
+		     * at all (or, bizarrely but legally, accepts the
+		     * user without actually issuing any prompts).
+		     * Give up on it entirely. */
+		    s->gotit = TRUE;
+		    if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
+			logevent("Keyboard-interactive authentication refused");
+		    s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
+		    s->kbd_inter_refused = TRUE; /* don't try it again */
+		    continue;
+		}
+
+		/*
+		 * Loop while the server continues to send INFO_REQUESTs.
+		 */
+		while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
+
+		    char *name, *inst, *lang;
+		    int name_len, inst_len, lang_len;
+		    int i;
+
+		    /*
+		     * We've got a fresh USERAUTH_INFO_REQUEST.
+		     * Get the preamble and start building a prompt.
+		     */
+		    ssh_pkt_getstring(pktin, &name, &name_len);
+		    ssh_pkt_getstring(pktin, &inst, &inst_len);
+		    ssh_pkt_getstring(pktin, &lang, &lang_len);
+		    s->cur_prompt = new_prompts(ssh->frontend);
+		    s->cur_prompt->to_server = TRUE;
+		    if (name_len) {
+			/* FIXME: better prefix to distinguish from
+			 * local prompts? */
+			s->cur_prompt->name =
+			    dupprintf("SSH server: %.*s", name_len, name);
+			s->cur_prompt->name_reqd = TRUE;
+		    } else {
+			s->cur_prompt->name =
+			    dupstr("SSH server authentication");
+			s->cur_prompt->name_reqd = FALSE;
+		    }
+		    /* FIXME: ugly to print "Using..." in prompt _every_
+		     * time round. Can this be done more subtly? */
+		    s->cur_prompt->instruction =
+			dupprintf("Using keyboard-interactive authentication.%s%.*s",
+				  inst_len ? "\n" : "", inst_len, inst);
+		    s->cur_prompt->instr_reqd = TRUE;
+
+		    /*
+		     * Get the prompts from the packet.
+		     */
+		    s->num_prompts = ssh_pkt_getuint32(pktin);
+		    for (i = 0; i < s->num_prompts; i++) {
+			char *prompt;
+			int prompt_len;
+			int echo;
+			static char noprompt[] =
+			    "<server failed to send prompt>: ";
+
+			ssh_pkt_getstring(pktin, &prompt, &prompt_len);
+			echo = ssh2_pkt_getbool(pktin);
+			if (!prompt_len) {
+			    prompt = noprompt;
+			    prompt_len = lenof(noprompt)-1;
+			}
+			add_prompt(s->cur_prompt,
+				   dupprintf("%.*s", prompt_len, prompt),
+				   echo, SSH_MAX_PASSWORD_LEN);
+		    }
+
+		    /*
+		     * Get the user's responses.
+		     */
+		    if (s->num_prompts) {
+			int ret; /* not live over crReturn */
+			ret = get_userpass_input(s->cur_prompt, NULL, 0);
+			while (ret < 0) {
+			    ssh->send_ok = 1;
+			    crWaitUntilV(!pktin);
+			    ret = get_userpass_input(s->cur_prompt, in, inlen);
+			    ssh->send_ok = 0;
+			}
+			if (!ret) {
+			    /*
+			     * Failed to get responses. Terminate.
+			     */
+			    free_prompts(s->cur_prompt);
+			    ssh_disconnect(ssh, NULL, "Unable to authenticate",
+					   SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
+					   TRUE);
+			    crStopV;
+			}
+		    }
+
+		    /*
+		     * Send the responses to the server.
+		     */
+		    s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
+		    ssh2_pkt_adduint32(s->pktout, s->num_prompts);
+		    for (i=0; i < s->num_prompts; i++) {
+			dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
+			ssh2_pkt_addstring(s->pktout,
+					   s->cur_prompt->prompts[i]->result);
+			end_log_omission(ssh, s->pktout);
+		    }
+		    ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
+
+		    /*
+		     * Get the next packet in case it's another
+		     * INFO_REQUEST.
+		     */
+		    crWaitUntilV(pktin);
+
+		}
+
+		/*
+		 * We should have SUCCESS or FAILURE now.
+		 */
+		s->gotit = TRUE;
+
+	    } else if (s->can_passwd) {
+
+		/*
+		 * Plain old password authentication.
+		 */
+		int ret; /* not live over crReturn */
+		int changereq_first_time; /* not live over crReturn */
+
+		ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
+		ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
+
+		s->cur_prompt = new_prompts(ssh->frontend);
+		s->cur_prompt->to_server = TRUE;
+		s->cur_prompt->name = dupstr("SSH password");
+		add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
+						    s->username,
+						    ssh->savedhost),
+			   FALSE, SSH_MAX_PASSWORD_LEN);
+
+		ret = get_userpass_input(s->cur_prompt, NULL, 0);
+		while (ret < 0) {
+		    ssh->send_ok = 1;
+		    crWaitUntilV(!pktin);
+		    ret = get_userpass_input(s->cur_prompt, in, inlen);
+		    ssh->send_ok = 0;
+		}
+		if (!ret) {
+		    /*
+		     * Failed to get responses. Terminate.
+		     */
+		    free_prompts(s->cur_prompt);
+		    ssh_disconnect(ssh, NULL, "Unable to authenticate",
+				   SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
+				   TRUE);
+		    crStopV;
+		}
+		/*
+		 * Squirrel away the password. (We may need it later if
+		 * asked to change it.)
+		 */
+		s->password = dupstr(s->cur_prompt->prompts[0]->result);
+		free_prompts(s->cur_prompt);
+
+		/*
+		 * Send the password packet.
+		 *
 		 * We pad out the password packet to 256 bytes to make
 		 * it harder for an attacker to find the length of the
 		 * user's password.
@@ -7170,67 +7698,205 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 		 * people who find out how long their password is!
 		 */
 		s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
-		s->pktout->forcepad = 256;
 		ssh2_pkt_addstring(s->pktout, s->username);
-		ssh2_pkt_addstring(s->pktout, "ssh-connection");	/* service requested */
+		ssh2_pkt_addstring(s->pktout, "ssh-connection");
+							/* service requested */
 		ssh2_pkt_addstring(s->pktout, "password");
 		ssh2_pkt_addbool(s->pktout, FALSE);
 		dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
 		ssh2_pkt_addstring(s->pktout, s->password);
-		memset(s->password, 0, sizeof(s->password));
 		end_log_omission(ssh, s->pktout);
-		ssh2_pkt_send(ssh, s->pktout);
+		ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
 		logevent("Sent password");
 		s->type = AUTH_TYPE_PASSWORD;
-	    } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
-		if (s->curr_prompt == 0) {
-		    s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
-		    s->pktout->forcepad = 256;
-		    ssh2_pkt_adduint32(s->pktout, s->num_prompts);
-		}
-		if (s->need_pw) {      /* only add pw if we just got one! */
+
+		/*
+		 * Wait for next packet, in case it's a password change
+		 * request.
+		 */
+		crWaitUntilV(pktin);
+		changereq_first_time = TRUE;
+
+		while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
+
+		    /* 
+		     * We're being asked for a new password
+		     * (perhaps not for the first time).
+		     * Loop until the server accepts it.
+		     */
+
+		    int got_new = FALSE; /* not live over crReturn */
+		    char *prompt;   /* not live over crReturn */
+		    int prompt_len; /* not live over crReturn */
+		    
+		    {
+			char *msg;
+			if (changereq_first_time)
+			    msg = "Server requested password change";
+			else
+			    msg = "Server rejected new password";
+			logevent(msg);
+			c_write_str(ssh, msg);
+			c_write_str(ssh, "\r\n");
+		    }
+
+		    ssh_pkt_getstring(pktin, &prompt, &prompt_len);
+
+		    s->cur_prompt = new_prompts(ssh->frontend);
+		    s->cur_prompt->to_server = TRUE;
+		    s->cur_prompt->name = dupstr("New SSH password");
+		    s->cur_prompt->instruction =
+			dupprintf("%.*s", prompt_len, prompt);
+		    s->cur_prompt->instr_reqd = TRUE;
+		    /*
+		     * There's no explicit requirement in the protocol
+		     * for the "old" passwords in the original and
+		     * password-change messages to be the same, and
+		     * apparently some Cisco kit supports password change
+		     * by the user entering a blank password originally
+		     * and the real password subsequently, so,
+		     * reluctantly, we prompt for the old password again.
+		     *
+		     * (On the other hand, some servers don't even bother
+		     * to check this field.)
+		     */
+		    add_prompt(s->cur_prompt,
+			       dupstr("Current password (blank for previously entered password): "),
+			       FALSE, SSH_MAX_PASSWORD_LEN);
+		    add_prompt(s->cur_prompt, dupstr("Enter new password: "),
+			       FALSE, SSH_MAX_PASSWORD_LEN);
+		    add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
+			       FALSE, SSH_MAX_PASSWORD_LEN);
+
+		    /*
+		     * Loop until the user manages to enter the same
+		     * password twice.
+		     */
+		    while (!got_new) {
+
+			ret = get_userpass_input(s->cur_prompt, NULL, 0);
+			while (ret < 0) {
+			    ssh->send_ok = 1;
+			    crWaitUntilV(!pktin);
+			    ret = get_userpass_input(s->cur_prompt, in, inlen);
+			    ssh->send_ok = 0;
+			}
+			if (!ret) {
+			    /*
+			     * Failed to get responses. Terminate.
+			     */
+			    /* burn the evidence */
+			    free_prompts(s->cur_prompt);
+			    memset(s->password, 0, strlen(s->password));
+			    sfree(s->password);
+			    ssh_disconnect(ssh, NULL, "Unable to authenticate",
+					   SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
+					   TRUE);
+			    crStopV;
+			}
+
+			/*
+			 * If the user specified a new original password
+			 * (IYSWIM), overwrite any previously specified
+			 * one.
+			 * (A side effect is that the user doesn't have to
+			 * re-enter it if they louse up the new password.)
+			 */
+			if (s->cur_prompt->prompts[0]->result[0]) {
+			    memset(s->password, 0, strlen(s->password));
+				/* burn the evidence */
+			    sfree(s->password);
+			    s->password =
+				dupstr(s->cur_prompt->prompts[0]->result);
+			}
+
+			/*
+			 * Check the two new passwords match.
+			 */
+			got_new = (strcmp(s->cur_prompt->prompts[1]->result,
+					  s->cur_prompt->prompts[2]->result)
+				   == 0);
+			if (!got_new)
+			    /* They don't. Silly user. */
+			    c_write_str(ssh, "Passwords do not match\r\n");
+
+		    }
+
+		    /*
+		     * Send the new password (along with the old one).
+		     * (see above for padding rationale)
+		     */
+		    s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+		    ssh2_pkt_addstring(s->pktout, s->username);
+		    ssh2_pkt_addstring(s->pktout, "ssh-connection");
+							/* service requested */
+		    ssh2_pkt_addstring(s->pktout, "password");
+		    ssh2_pkt_addbool(s->pktout, TRUE);
 		    dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
 		    ssh2_pkt_addstring(s->pktout, s->password);
-		    memset(s->password, 0, sizeof(s->password));
+		    ssh2_pkt_addstring(s->pktout,
+				       s->cur_prompt->prompts[1]->result);
+		    free_prompts(s->cur_prompt);
 		    end_log_omission(ssh, s->pktout);
-		    s->curr_prompt++;
-		}
-		if (s->curr_prompt >= s->num_prompts) {
-		    ssh2_pkt_send(ssh, s->pktout);
-		} else {
+		    ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
+		    logevent("Sent new password");
+		    
 		    /*
-		     * If there are prompts remaining, we set
-		     * `gotit' so that we won't attempt to get
-		     * another packet. Then we go back round the
-		     * loop and will end up retrieving another
-		     * prompt out of the existing packet. Funky or
-		     * what?
+		     * Now see what the server has to say about it.
+		     * (If it's CHANGEREQ again, it's not happy with the
+		     * new password.)
 		     */
-		    s->gotit = TRUE;
+		    crWaitUntilV(pktin);
+		    changereq_first_time = FALSE;
+
 		}
-		s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
+
+		/*
+		 * We need to reexamine the current pktin at the top
+		 * of the loop. Either:
+		 *  - we weren't asked to change password at all, in
+		 *    which case it's a SUCCESS or FAILURE with the
+		 *    usual meaning
+		 *  - we sent a new password, and the server was
+		 *    either OK with it (SUCCESS or FAILURE w/partial
+		 *    success) or unhappy with the _old_ password
+		 *    (FAILURE w/o partial success)
+		 * In any of these cases, we go back to the top of
+		 * the loop and start again.
+		 */
+		s->gotit = TRUE;
+
+		/*
+		 * We don't need the old password any more, in any
+		 * case. Burn the evidence.
+		 */
+		memset(s->password, 0, strlen(s->password));
+		sfree(s->password);
+
 	    } else {
-		c_write_str(ssh, "No supported authentication methods"
-			    " left to try!\r\n");
-		logevent("No supported authentications offered."
-			 " Disconnecting");
-		s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
-		ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
-		ssh2_pkt_addstring(s->pktout, "No supported authentication"
-				   " methods available");
-		ssh2_pkt_addstring(s->pktout, "en");	/* language tag */
-		ssh2_pkt_send_noqueue(ssh, s->pktout);
-		ssh->close_expected = TRUE;
-                ssh_closing((Plug)ssh, NULL, 0, 0);
+
+		ssh_disconnect(ssh, NULL,
+			       "No supported authentication methods available",
+			       SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
+			       FALSE);
 		crStopV;
+
 	    }
+
 	}
-    } while (!s->we_are_in);
+    }
+    ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
+
+    /* Clear up various bits and pieces from authentication. */
+    if (s->publickey_blob) {
+	sfree(s->publickey_blob);
+	sfree(s->publickey_comment);
+    }
+    if (s->agent_response)
+	sfree(s->agent_response);
 
     /*
-     * Now we're authenticated for the connection protocol. The
-     * connection protocol will automatically have started at this
-     * point; there's no need to send SERVICE_REQUEST.
+     * Now the connection protocol has started, one way or another.
      */
 
     ssh->channels = newtree234(ssh_channelcmp);
@@ -7247,7 +7913,58 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
     /*
      * Create the main session channel.
      */
-    if (!ssh->cfg.ssh_no_shell) {
+    if (ssh->cfg.ssh_no_shell) {
+	ssh->mainchan = NULL;
+    } else if (*ssh->cfg.ssh_nc_host) {
+	/*
+	 * Just start a direct-tcpip channel and use it as the main
+	 * channel.
+	 */
+	ssh->mainchan = snew(struct ssh_channel);
+	ssh->mainchan->ssh = ssh;
+	ssh->mainchan->localid = alloc_channel_id(ssh);
+	logeventf(ssh,
+		  "Opening direct-tcpip channel to %s:%d in place of session",
+		  ssh->cfg.ssh_nc_host, ssh->cfg.ssh_nc_port);
+	s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
+	ssh2_pkt_addstring(s->pktout, "direct-tcpip");
+	ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
+	ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
+	ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
+	ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT);      /* our max pkt size */
+	ssh2_pkt_addstring(s->pktout, ssh->cfg.ssh_nc_host);
+	ssh2_pkt_adduint32(s->pktout, ssh->cfg.ssh_nc_port);
+	/*
+	 * There's nothing meaningful to put in the originator
+	 * fields, but some servers insist on syntactically correct
+	 * information.
+	 */
+	ssh2_pkt_addstring(s->pktout, "0.0.0.0");
+	ssh2_pkt_adduint32(s->pktout, 0);
+	ssh2_pkt_send(ssh, s->pktout);
+
+	crWaitUntilV(pktin);
+	if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
+	    bombout(("Server refused to open a direct-tcpip channel"));
+	    crStopV;
+	    /* FIXME: error data comes back in FAILURE packet */
+	}
+	if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
+	    bombout(("Server's channel confirmation cited wrong channel"));
+	    crStopV;
+	}
+	ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
+	ssh->mainchan->halfopen = FALSE;
+	ssh->mainchan->type = CHAN_MAINSESSION;
+	ssh->mainchan->closes = 0;
+	ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
+	ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
+	bufchain_init(&ssh->mainchan->v.v2.outbuffer);
+	add234(ssh->channels, ssh->mainchan);
+	update_specials_menu(ssh->frontend);
+	logevent("Opened direct-tcpip channel");
+	ssh->ncmode = TRUE;
+    } else {
 	ssh->mainchan = snew(struct ssh_channel);
 	ssh->mainchan->ssh = ssh;
 	ssh->mainchan->localid = alloc_channel_id(ssh);
@@ -7278,8 +7995,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 	add234(ssh->channels, ssh->mainchan);
 	update_specials_menu(ssh->frontend);
 	logevent("Opened channel for session");
-    } else
-	ssh->mainchan = NULL;
+	ssh->ncmode = FALSE;
+    }
 
     /*
      * Now we have a channel, make dispatch table entries for
@@ -7302,7 +8019,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
     /*
      * Potentially enable X11 forwarding.
      */
-    if (ssh->mainchan && ssh->cfg.x11_forward) {
+    if (ssh->mainchan && !ssh->ncmode && ssh->cfg.x11_forward) {
 	char proto[20], data[64];
 	logevent("Requesting X11 forwarding");
 	ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
@@ -7314,6 +8031,13 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 	ssh2_pkt_addbool(s->pktout, 1);	       /* want reply */
 	ssh2_pkt_addbool(s->pktout, 0);	       /* many connections */
 	ssh2_pkt_addstring(s->pktout, proto);
+	/*
+	 * Note that while we blank the X authentication data here, we don't
+	 * take any special action to blank the start of an X11 channel,
+	 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
+	 * without having session blanking enabled is likely to leak your
+	 * cookie into the log.
+	 */
 	dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
 	ssh2_pkt_addstring(s->pktout, data);
 	end_log_omission(ssh, s->pktout);
@@ -7343,7 +8067,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
     /*
      * Potentially enable agent forwarding.
      */
-    if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
+    if (ssh->mainchan && !ssh->ncmode && ssh->cfg.agentfwd && agent_exists()) {
 	logevent("Requesting OpenSSH-style agent forwarding");
 	s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
 	ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
@@ -7369,7 +8093,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
     /*
      * Now allocate a pty for the session.
      */
-    if (ssh->mainchan && !ssh->cfg.nopty) {
+    if (ssh->mainchan && !ssh->ncmode && !ssh->cfg.nopty) {
 	/* Unpick the terminal-speed string. */
 	/* XXX perhaps we should allow no speeds to be sent. */
         ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
@@ -7419,7 +8143,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
      * Simplest thing here is to send all the requests at once, and
      * then wait for a whole bunch of successes or failures.
      */
-    if (ssh->mainchan && *ssh->cfg.environmt) {
+    if (ssh->mainchan && !ssh->ncmode && *ssh->cfg.environmt) {
 	char *e = ssh->cfg.environmt;
 	char *var, *varend, *val;
 
@@ -7484,7 +8208,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
      * this twice if the config data has provided a second choice
      * of command.
      */
-    if (ssh->mainchan) while (1) {
+    if (ssh->mainchan && !ssh->ncmode) while (1) {
 	int subsys;
 	char *cmd;
 
@@ -7789,6 +8513,7 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle,
     ssh->hostkey = NULL;
     ssh->exitcode = -1;
     ssh->close_expected = FALSE;
+    ssh->clean_exit = FALSE;
     ssh->state = SSH_STATE_PREPACKET;
     ssh->size_needed = FALSE;
     ssh->eof_needed = FALSE;
@@ -7814,6 +8539,8 @@ static const 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->v_c = NULL;
+    ssh->v_s = NULL;
     ssh->mainchan = NULL;
     ssh->throttled_all = 0;
     ssh->v1_stdout_throttling = 0;
@@ -7941,6 +8668,8 @@ static void ssh_free(void *handle)
     sfree(ssh->do_ssh1_login_state);
     sfree(ssh->do_ssh2_transport_state);
     sfree(ssh->do_ssh2_authconn_state);
+    sfree(ssh->v_c);
+    sfree(ssh->v_s);
     if (ssh->crcda_ctx) {
 	crcda_free_context(ssh->crcda_ctx);
 	ssh->crcda_ctx = NULL;
@@ -7966,7 +8695,8 @@ static void ssh_reconfig(void *handle, Config *cfg)
     unsigned long old_max_data_size;
 
     pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
-    ssh_setup_portfwd(ssh, cfg);
+    if (ssh->portfwds)
+	ssh_setup_portfwd(ssh, cfg);
 
     if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
 	cfg->ssh_rekey_time != 0) {
@@ -8013,7 +8743,7 @@ static void ssh_reconfig(void *handle, Config *cfg)
 }
 
 /*
- * Called to send data down the Telnet connection.
+ * Called to send data down the SSH connection.
  */
 static int ssh_send(void *handle, char *buf, int len)
 {
@@ -8170,7 +8900,7 @@ static const struct telnet_special *ssh_get_specials(void *handle)
 }
 
 /*
- * Send Telnet special codes. TS_EOF is useful for `plink', so you
+ * Send special codes. TS_EOF is useful for `plink', so you
  * can send an EOF and collect resulting output (e.g. `plink
  * hostname sort').
  */
@@ -8293,8 +9023,7 @@ static void ssh_unthrottle(void *handle, int bufsize)
 	    ssh1_throttle(ssh, -1);
 	}
     } else {
-	if (ssh->mainchan && ssh->mainchan->closes == 0)
-	    ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
+	ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
     }
 }
 
@@ -8327,17 +9056,20 @@ void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
 	 * 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.
+	 * The "originator IP address" is syntactically a numeric
+	 * IP address, and some servers (e.g., Tectia) get upset
+	 * if it doesn't match this syntax.
 	 */
-	ssh2_pkt_addstring(pktout, "client-side-connection");
+	ssh2_pkt_addstring(pktout, "0.0.0.0");
 	ssh2_pkt_adduint32(pktout, 0);
 	ssh2_pkt_send(ssh, pktout);
     }
 }
 
-static Socket ssh_socket(void *handle)
+static int ssh_connected(void *handle)
 {
     Ssh ssh = (Ssh) handle;
-    return ssh->s;
+    return ssh->s != NULL;
 }
 
 static int ssh_sendok(void *handle)
@@ -8374,7 +9106,7 @@ static int ssh_return_exitcode(void *handle)
     if (ssh->s != NULL)
         return -1;
     else
-        return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
+        return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
 }
 
 /*
@@ -8407,7 +9139,7 @@ Backend ssh_backend = {
     ssh_size,
     ssh_special,
     ssh_get_specials,
-    ssh_socket,
+    ssh_connected,
     ssh_return_exitcode,
     ssh_sendok,
     ssh_ldisc,