- OpenBSD CVS updates:

  - markus@cvs.openbsd.org
    [session.c]
    make x11-fwd work w/ localhost (xauth add host/unix:11)
    [cipher.c compat.c readconf.c servconf.c]
    check strtok() != NULL; ok niels@
    [key.c]
    fix key_read() for uuencoded keys w/o '='
    [serverloop.c]
    group ssh1 vs. ssh2 in serverloop
    [kex.c kex.h myproposal.h sshconnect2.c sshd.c]
    split kexinit/kexdh, factor out common code
    [readconf.c ssh.1 ssh.c]
    forwardagent defaults to no, add ssh -A
  - theo@cvs.openbsd.org
    [session.c]
    just some line shortening

15 files changed, 256 insertions, 207 deletions

diff --git a/ChangeLog b/ChangeLog
index 3037eac3..f8dcd9ce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,23 @@
  - Define atexit for old Solaris
  - Fix buffer overrun in login.c for systems which use syslen in utmpx.
    patch from YOSHIFUJI Hideaki <yoshfuji@cerberus.nemoto.ecei.tohoku.ac.jp>
+ - OpenBSD CVS updates:
+  - markus@cvs.openbsd.org
+    [session.c]
+    make x11-fwd work w/ localhost (xauth add host/unix:11)
+    [cipher.c compat.c readconf.c servconf.c]
+    check strtok() != NULL; ok niels@
+    [key.c]
+    fix key_read() for uuencoded keys w/o '='
+    [serverloop.c]
+    group ssh1 vs. ssh2 in serverloop
+    [kex.c kex.h myproposal.h sshconnect2.c sshd.c]
+    split kexinit/kexdh, factor out common code
+    [readconf.c ssh.1 ssh.c]
+    forwardagent defaults to no, add ssh -A
+  - theo@cvs.openbsd.org
+    [session.c]
+    just some line shortening
 
 20000520
  - Xauth fix from Markus Friedl <markus.friedl@informatik.uni-erlangen.de>
diff --git a/cipher.c b/cipher.c
index 639c1abb..4117cb77 100644
--- a/cipher.c
+++ b/cipher.c
@@ -12,7 +12,7 @@
  */
 
 #include "includes.h"
-RCSID("$Id: cipher.c,v 1.20 2000/04/16 02:31:50 damien Exp $");
+RCSID("$Id: cipher.c,v 1.21 2000/05/30 03:44:52 damien Exp $");
 
 #include "ssh.h"
 #include "cipher.h"
@@ -178,7 +178,7 @@ ciphers_valid(const char *names)
 	char *p;
 	int i;
 
-	if (strcmp(names, "") == 0)
+	if (names == NULL || strcmp(names, "") == 0)
 		return 0;
 	ciphers = xstrdup(names);
 	for ((p = strtok(ciphers, CIPHER_SEP)); p; (p = strtok(NULL, CIPHER_SEP))) {
@@ -201,6 +201,8 @@ int
 cipher_number(const char *name)
 {
 	int i;
+	if (name == NULL)
+		return -1;
 	for (i = 0; i < sizeof(cipher_names) / sizeof(cipher_names[0]); i++)
 		if (strcmp(cipher_names[i], name) == 0 &&
 		    (cipher_mask() & (1 << i)))
diff --git a/compat.c b/compat.c
index 00f031b8..967e0b6b 100644
--- a/compat.c
+++ b/compat.c
@@ -28,7 +28,7 @@
  */
 
 #include "includes.h"
-RCSID("$Id: compat.c,v 1.10 2000/05/09 01:03:00 damien Exp $");
+RCSID("$Id: compat.c,v 1.11 2000/05/30 03:44:53 damien Exp $");
 
 #include "ssh.h"
 #include "packet.h"
@@ -80,10 +80,12 @@ compat_datafellows(const char *version)
 int
 proto_spec(const char *spec)
 {
-	char *s = xstrdup(spec);
-	char *p;
+	char *s, *p;
 	int ret = SSH_PROTO_UNKNOWN;
 
+	if (spec == NULL)
+		return ret;
+	s = xstrdup(spec);
 	for ((p = strtok(s, SEP)); p; (p = strtok(NULL, SEP))) {
 		switch(atoi(p)) {
 		case 1:
diff --git a/kex.c b/kex.c
index 221e0304..199e0426 100644
--- a/kex.c
+++ b/kex.c
@@ -28,13 +28,14 @@
  */
 
 #include "includes.h"
-RCSID("$Id: kex.c,v 1.8 2000/05/09 01:03:01 damien Exp $");
+RCSID("$Id: kex.c,v 1.9 2000/05/30 03:44:53 damien Exp $");
 
 #include "ssh.h"
 #include "ssh2.h"
 #include "xmalloc.h"
 #include "buffer.h"
 #include "bufaux.h"
+#include "packet.h"
 #include "cipher.h"
 #include "compat.h"
 
@@ -49,15 +50,17 @@ RCSID("$Id: kex.c,v 1.8 2000/05/09 01:03:01 damien Exp $");
 
 #include "kex.h"
 
+#define KEX_COOKIE_LEN	16
+
 Buffer *
 kex_init(char *myproposal[PROPOSAL_MAX])
 {
-	char c = 0;
-	unsigned char cookie[16];
+	int first_kex_packet_follows = 0;
+	unsigned char cookie[KEX_COOKIE_LEN];
 	u_int32_t rand = 0;
 	int i;
 	Buffer *ki = xmalloc(sizeof(*ki));
-	for (i = 0; i < 16; i++) {
+	for (i = 0; i < KEX_COOKIE_LEN; i++) {
 		if (i % 4 == 0)
 			rand = arc4random();
 		cookie[i] = rand & 0xff;
@@ -67,11 +70,55 @@ kex_init(char *myproposal[PROPOSAL_MAX])
 	buffer_append(ki, (char *)cookie, sizeof cookie);
 	for (i = 0; i < PROPOSAL_MAX; i++)
 		buffer_put_cstring(ki, myproposal[i]);
-	buffer_append(ki, &c, 1); /* boolean   first_kex_packet_follows */
-	buffer_put_int(ki, 0);    /* uint32    0 (reserved for future extension) */
+	buffer_put_char(ki, first_kex_packet_follows);
+	buffer_put_int(ki, 0);				/* uint32 reserved */
 	return ki;
 }
 
+/* send kexinit, parse and save reply */
+void
+kex_exchange_kexinit(
+    Buffer *my_kexinit, Buffer *peer_kexint,
+    char *peer_proposal[PROPOSAL_MAX])
+{
+	int i;
+	char *ptr;
+	int plen;
+
+	debug("send KEXINIT");
+	packet_start(SSH2_MSG_KEXINIT);
+	packet_put_raw(buffer_ptr(my_kexinit), buffer_len(my_kexinit));	
+	packet_send();
+	packet_write_wait();
+	debug("done");
+
+	/*
+	 * read and save raw KEXINIT payload in buffer. this is used during
+	 * computation of the session_id and the session keys.
+	 */
+	debug("wait KEXINIT");
+	packet_read_expect(&plen, SSH2_MSG_KEXINIT);
+	ptr = packet_get_raw(&plen);
+	buffer_append(peer_kexint, ptr, plen);
+
+	/* parse packet and save algorithm proposal */
+	/* skip cookie */
+	for (i = 0; i < KEX_COOKIE_LEN; i++)
+		packet_get_char();
+	/* extract kex init proposal strings */
+	for (i = 0; i < PROPOSAL_MAX; i++) {
+		peer_proposal[i] = packet_get_string(NULL);
+		debug("got kexinit: %s", peer_proposal[i]);
+	}
+	/* first kex follow / reserved */
+	i = packet_get_char();
+	debug("first kex follow: %d ", i);
+	i = packet_get_int();
+	debug("reserved: %d ", i);
+	packet_done();
+	debug("done");
+}
+
 /* diffie-hellman-group1-sha1 */
 
 int
@@ -134,12 +181,6 @@ dh_new_group1()
 }
 
 void
-bignum_print(BIGNUM *b)
-{
-	BN_print_fp(stderr,b);
-}
-
-void
 dump_digest(unsigned char *digest, int len)
 {
 	int i;
@@ -246,10 +287,13 @@ char *
 get_match(char *client, char *server)
 {
 	char *sproposals[MAX_PROP];
-	char *p;
+	char *c, *s, *p, *ret;
 	int i, j, nproposals;
 
-	for ((p = strtok(server, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
+	c = xstrdup(client);
+	s = xstrdup(server);
+
+	for ((p = strtok(s, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
 		if (i < MAX_PROP)
 			sproposals[i] = p;
 		else
@@ -257,11 +301,18 @@ get_match(char *client, char *server)
 	}
 	nproposals = i;
 
-	for ((p = strtok(client, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
-		for (j = 0; j < nproposals; j++)
-			if (strcmp(p, sproposals[j]) == 0)
-				return xstrdup(p);
+	for ((p = strtok(c, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
+		for (j = 0; j < nproposals; j++) {
+			if (strcmp(p, sproposals[j]) == 0) {
+				ret = xstrdup(p);
+				xfree(c);
+				xfree(s);
+				return ret;
+			}
+		}
 	}
+	xfree(c);
+	xfree(s);
 	return NULL;
 }
 void
@@ -355,7 +406,6 @@ choose_hostkeyalg(Kex *k, char *client, char *server)
 Kex *
 kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server)
 {
-	int i;
 	int mode;
 	int ctos;				/* direction: if true client-to-server */
 	int need;
@@ -383,10 +433,6 @@ kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server
 	choose_kex(k, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
 	choose_hostkeyalg(k, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
 	    sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
-	for (i = 0; i < PROPOSAL_MAX; i++) {
-		xfree(cprop[i]);
-		xfree(sprop[i]);
-	}
 	need = 0;
 	for (mode = 0; mode < MODE_MAX; mode++) {
 	    if (need < k->enc[mode].key_len)
@@ -396,9 +442,7 @@ kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server
 	    if (need < k->mac[mode].key_len)
 		    need = k->mac[mode].key_len;
 	}
-	/* need runden? */
-#define WE_NEED 32
-	k->we_need = WE_NEED;
+	/* XXX need runden? */
 	k->we_need = need;
 	return k;
 }
diff --git a/kex.h b/kex.h
index 5395ebc3..7e5c6702 100644
--- a/kex.h
+++ b/kex.h
@@ -91,12 +91,17 @@ struct Kex {
 };
 
 Buffer	*kex_init(char *myproposal[PROPOSAL_MAX]);
-int	dh_pub_is_valid(DH *dh, BIGNUM *dh_pub);
-DH	*dh_new_group1();
-Kex 	*kex_choose_conf(char *cprop[PROPOSAL_MAX], char *sprop[PROPOSAL_MAX], int server);
+void
+kex_exchange_kexinit(
+    Buffer *my_kexinit, Buffer *peer_kexint,
+    char *peer_proposal[PROPOSAL_MAX]);
+Kex *
+kex_choose_conf(char *cprop[PROPOSAL_MAX],
+    char *sprop[PROPOSAL_MAX], int server);
 int	kex_derive_keys(Kex *k, unsigned char *hash, BIGNUM *shared_secret);
-void	bignum_print(BIGNUM *b);
 void	packet_set_kex(Kex *k);
+int	dh_pub_is_valid(DH *dh, BIGNUM *dh_pub);
+DH	*dh_new_group1();
 
 unsigned char *
 kex_hash(
diff --git a/key.c b/key.c
index ae355a3f..d474f85c 100644
--- a/key.c
+++ b/key.c
@@ -256,12 +256,14 @@ key_read(Key *ret, char **cpp)
 		blob = xmalloc(len);
 		n = uudecode(cp, blob, len);
 		if (n < 0) {
-			error("uudecode %s failed", cp);
+			error("key_read: uudecode %s failed", cp);
 			return 0;
 		}
 		k = dsa_key_from_blob(blob, n);
-		if (k == NULL)
-			 return 0;
+		if (k == NULL) {
+			error("key_read: dsa_key_from_blob %s failed", cp);
+			return 0;
+		}
 		xfree(blob);
 		if (ret->dsa != NULL)
 			DSA_free(ret->dsa);
@@ -269,10 +271,12 @@ key_read(Key *ret, char **cpp)
 		k->dsa = NULL;
 		key_free(k);
 		bits = BN_num_bits(ret->dsa->p);
-		cp = strchr(cp, '=');
-		if (cp == NULL)
-			return 0;
-		*cpp = cp + 1;
+		/* advance cp: skip whitespace and data */
+		while (*cp == ' ' || *cp == '\t')
+			cp++;
+		while (*cp != '\0' && *cp != ' ' && *cp != '\t')
+			cp++;
+		*cpp = cp;
 		break;
 	default:
 		fatal("key_read: bad key type: %d", ret->type);
diff --git a/myproposal.h b/myproposal.h
index 8b241797..9611d895 100644
--- a/myproposal.h
+++ b/myproposal.h
@@ -6,7 +6,7 @@
 #define	KEX_DEFAULT_LANG	""
 
 
-static const char *myproposal[PROPOSAL_MAX] = {
+static char *myproposal[PROPOSAL_MAX] = {
 	KEX_DEFAULT_KEX,
 	KEX_DEFAULT_PK_ALG,
 	KEX_DEFAULT_ENCRYPT,
diff --git a/readconf.c b/readconf.c
index 9c5638b0..d7011d7f 100644
--- a/readconf.c
+++ b/readconf.c
@@ -14,7 +14,7 @@
  */
 
 #include "includes.h"
-RCSID("$Id: readconf.c,v 1.14 2000/05/09 01:03:01 damien Exp $");
+RCSID("$Id: readconf.c,v 1.15 2000/05/30 03:44:53 damien Exp $");
 
 #include "ssh.h"
 #include "cipher.h"
@@ -464,6 +464,8 @@ parse_int:
 	case oCipher:
 		intptr = &options->cipher;
 		cp = strtok(NULL, WHITESPACE);
+		if (!cp)
+			fatal("%.200s line %d: Missing argument.", filename, linenum);
 		value = cipher_number(cp);
 		if (value == -1)
 			fatal("%.200s line %d: Bad cipher '%s'.",
@@ -474,6 +476,8 @@ parse_int:
 
 	case oCiphers:
 		cp = strtok(NULL, WHITESPACE);
+		if (!cp)
+			fatal("%.200s line %d: Missing argument.", filename, linenum);
 		if (!ciphers_valid(cp))
 			fatal("%.200s line %d: Bad SSH2 cipher spec '%s'.",
 			      filename, linenum, cp ? cp : "<NONE>");
@@ -484,6 +488,8 @@ parse_int:
 	case oProtocol:
 		intptr = &options->protocol;
 		cp = strtok(NULL, WHITESPACE);
+		if (!cp)
+			fatal("%.200s line %d: Missing argument.", filename, linenum);
 		value = proto_spec(cp);
 		if (value == SSH_PROTO_UNKNOWN)
 			fatal("%.200s line %d: Bad protocol spec '%s'.",
@@ -691,7 +697,7 @@ void
 fill_default_options(Options * options)
 {
 	if (options->forward_agent == -1)
-		options->forward_agent = 1;
+		options->forward_agent = 0;
 	if (options->forward_x11 == -1)
 		options->forward_x11 = 0;
 	if (options->gateway_ports == -1)
diff --git a/servconf.c b/servconf.c
index 05630c76..1aa4fe06 100644
--- a/servconf.c
+++ b/servconf.c
@@ -12,7 +12,7 @@
  */
 
 #include "includes.h"
-RCSID("$Id: servconf.c,v 1.16 2000/05/09 01:03:01 damien Exp $");
+RCSID("$Id: servconf.c,v 1.17 2000/05/30 03:44:53 damien Exp $");
 
 #include "ssh.h"
 #include "servconf.h"
@@ -588,6 +588,8 @@ parse_flag:
 
 		case sCiphers:
 			cp = strtok(NULL, WHITESPACE);
+			if (!cp)
+				fatal("%s line %d: Missing argument.", filename, linenum);
 			if (!ciphers_valid(cp))
 				fatal("%s line %d: Bad SSH2 cipher spec '%s'.",
 				    filename, linenum, cp ? cp : "<NONE>");
@@ -598,6 +600,8 @@ parse_flag:
 		case sProtocol:
 			intptr = &options->protocol;
 			cp = strtok(NULL, WHITESPACE);
+			if (!cp)
+				fatal("%s line %d: Missing argument.", filename, linenum);
 			value = proto_spec(cp);
 			if (value == SSH_PROTO_UNKNOWN)
 				fatal("%s line %d: Bad protocol spec '%s'.",
diff --git a/serverloop.c b/serverloop.c
index 977ed41f..b08fcfd9 100644
--- a/serverloop.c
+++ b/serverloop.c
@@ -164,33 +164,37 @@ retry_select:
 
 	/* Initialize select() masks. */
 	FD_ZERO(readset);
+	FD_ZERO(writeset);
 
-	/*
-	 * Read packets from the client unless we have too much buffered
-	 * stdin or channel data.
-	 */
 	if (compat20) {
 		/* wrong: bad condition XXX */
 		if (channel_not_very_much_buffered_data())
 			FD_SET(connection_in, readset);
 	} else {
-		if (buffer_len(&stdin_buffer) < 4096 &&
+		/*
+		 * Read packets from the client unless we have too much
+		 * buffered stdin or channel data.
+		 */
+		if (buffer_len(&stdin_buffer) < buffer_high &&
 		    channel_not_very_much_buffered_data())
 			FD_SET(connection_in, readset);
+		/*
+		 * If there is not too much data already buffered going to
+		 * the client, try to get some more data from the program.
+		 */
+		if (packet_not_very_much_data_to_write()) {
+			if (!fdout_eof)
+				FD_SET(fdout, readset);
+			if (!fderr_eof)
+				FD_SET(fderr, readset);
+		}
+		/*
+		 * If we have buffered data, try to write some of that data
+		 * to the program.
+		 */
+		if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
+			FD_SET(fdin, writeset);
 	}
-
-	/*
-	 * If there is not too much data already buffered going to the
-	 * client, try to get some more data from the program.
-	 */
-	if (!compat20 && packet_not_very_much_data_to_write()) {
-		if (!fdout_eof)
-			FD_SET(fdout, readset);
-		if (!fderr_eof)
-			FD_SET(fderr, readset);
-	}
-	FD_ZERO(writeset);
-
 	/* Set masks for channel descriptors. */
 	channel_prepare_select(readset, writeset);
 
@@ -201,11 +205,6 @@ retry_select:
 	if (packet_have_data_to_write())
 		FD_SET(connection_out, writeset);
 
-	/* If we have buffered data, try to write some of that data to the
-	   program. */
-	if (!compat20 && fdin != -1 && buffer_len(&stdin_buffer) > 0)
-		FD_SET(fdin, writeset);
-
 	/* Update the maximum descriptor number if appropriate. */
 	if (channel_max_fd() > max_fd)
 		max_fd = channel_max_fd();
@@ -377,6 +376,7 @@ process_buffered_input_packets()
 void
 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
 {
+	fd_set readset, writeset;
 	int wait_status;	/* Status returned by wait(). */
 	pid_t wait_pid;		/* pid returned by wait(). */
 	int waiting_termination = 0;	/* Have displayed waiting close message. */
@@ -445,7 +445,6 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
 
 	/* Main loop of the server for the interactive session mode. */
 	for (;;) {
-		fd_set readset, writeset;
 
 		/* Process buffered packets from the client. */
 		process_buffered_input_packets();
@@ -717,6 +716,9 @@ input_direct_tcpip(void)
 	originator = packet_get_string(NULL);
 	originator_port = packet_get_int();
 	packet_done();
+
+	debug("open direct-tcpip: from %s port %d to %s port %d",
+	   originator, originator_port, target, target_port);
 	/* XXX check permission */
 	sock = channel_connect_to(target, target_port);
 	xfree(target);
@@ -768,7 +770,6 @@ server_input_channel_open(int type, int plen)
 			channel_free(id);
 		}
 	} else if (strcmp(ctype, "direct-tcpip") == 0) {
-		debug("open direct-tcpip");
 		id = input_direct_tcpip();
 		if (id >= 0)
 			c = channel_lookup(id);
diff --git a/session.c b/session.c
index 4b7404f7..4791857c 100644
--- a/session.c
+++ b/session.c
@@ -8,7 +8,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: session.c,v 1.12 2000/05/03 18:03:07 markus Exp $");
+RCSID("$OpenBSD: session.c,v 1.14 2000/05/25 03:10:18 deraadt Exp $");
 
 #include "xmalloc.h"
 #include "ssh.h"
@@ -645,7 +645,8 @@ do_exec_pty(Session *s, const char *command, struct passwd * pw)
 		}
 #endif
 		/* Do common processing for the child, such as execing the command. */
-		do_child(command, pw, s->term, s->display, s->auth_proto, s->auth_data, s->tty);
+		do_child(command, pw, s->term, s->display, s->auth_proto,
+		    s->auth_data, s->tty);
 		/* NOTREACHED */
 	}
 	if (pid < 0)
@@ -749,7 +750,10 @@ read_environment_file(char ***env, unsigned int *envsize,
 			fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
 			continue;
 		}
-		/* Replace the equals sign by nul, and advance value to the value string. */
+		/*
+		 * Replace the equals sign by nul, and advance value to
+		 * the value string.
+		 */
 		*value = '\0';
 		value++;
 		child_set_env(env, envsize, cp, value);
@@ -948,7 +952,8 @@ do_child(const char *command, struct passwd * pw, const char *term,
 
 	/* read $HOME/.ssh/environment. */
 	if (!options.use_login) {
-		snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir);
+		snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
+		    pw->pw_dir);
 		read_environment_file(&env, &envsize, buf);
 	}
 	if (debug_flag) {
@@ -1037,21 +1042,27 @@ do_child(const char *command, struct passwd * pw, const char *term,
 			if (auth_proto != NULL && auth_data != NULL) {
 				char *screen = strchr(display, ':');
 				if (debug_flag) {
-					fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n",
+					fprintf(stderr,
+					    "Running %.100s add %.100s %.100s %.100s\n",
 					    XAUTH_PATH, display, auth_proto, auth_data);
 					if (screen != NULL)
-						fprintf(stderr, "Adding %.*s/unix%s %s %s\n",
-						    screen-display, display, screen, auth_proto, auth_data);
+						fprintf(stderr,
+						    "Adding %.*s/unix%s %s %s\n",
+						    screen-display, display,
+						    screen, auth_proto, auth_data);
 				}
 				f = popen(XAUTH_PATH " -q -", "w");
 				if (f) {
-					fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data);
+					fprintf(f, "add %s %s %s\n", display,
+					    auth_proto, auth_data);
 					if (screen != NULL) 
 						fprintf(f, "add %.*s/unix%s %s %s\n",
-						     screen-display, display, screen, auth_proto, auth_data);
+						    screen-display, display,
+						    screen, auth_proto, auth_data);
 					pclose(f);
 				} else
-					fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH);
+					fprintf(stderr, "Could not run %s -q -\n",
+					    XAUTH_PATH);
 			}
 		}
 #endif /* XAUTH_PATH */
@@ -1081,7 +1092,8 @@ do_child(const char *command, struct passwd * pw, const char *term,
 				struct stat mailstat;
 				mailbox = getenv("MAIL");
 				if (mailbox != NULL) {
-					if (stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0)
+					if (stat(mailbox, &mailstat) != 0 ||
+					    mailstat.st_size == 0)
 						printf("No mail.\n");
 					else if (mailstat.st_mtime < mailstat.st_atime)
 						printf("You have mail.\n");
diff --git a/ssh.1 b/ssh.1
index d8e9eb0b..6c1d3763 100644
--- a/ssh.1
+++ b/ssh.1
@@ -9,7 +9,7 @@
 .\"
 .\" Created: Sat Apr 22 21:55:14 1995 ylo
 .\"
-.\" $Id: ssh.1,v 1.26 2000/05/17 12:34:24 damien Exp $
+.\" $Id: ssh.1,v 1.27 2000/05/30 03:44:54 damien Exp $
 .\"
 .Dd September 25, 1999
 .Dt SSH 1
@@ -24,7 +24,7 @@
 .Op Ar command
 .Pp
 .Nm ssh
-.Op Fl afgknqtvxCNPTX246
+.Op Fl afgknqtvxACNPTX246
 .Op Fl c Ar cipher_spec
 .Op Fl e Ar escape_char
 .Op Fl i Ar identity_file
@@ -332,7 +332,9 @@ host key is not known or has changed.
 .Bl -tag -width Ds
 .It Fl a
 Disables forwarding of the authentication agent connection.
-This may also be specified on a per-host basis in the configuration file.
+.It Fl A
+Enables forwarding of the authentication agent connection.
+This can also be specified on a per-host basis in a configuration file.
 .It Fl c Ar blowfish|3des
 Selects the cipher to use for encrypting the session.
 .Ar 3des
@@ -460,9 +462,9 @@ The verbose mode is also used to display
 challenges, if the user entered "s/key" as password.
 .It Fl x
 Disables X11 forwarding.
-This can also be specified on a per-host basis in a configuration file.
 .It Fl X
 Enables X11 forwarding.
+This can also be specified on a per-host basis in a configuration file.
 .It Fl C
 Requests compression of all data (including stdin, stdout, stderr, and
 data for forwarded X11 and TCP/IP connections).
@@ -671,6 +673,8 @@ The argument must be
 .Dq yes
 or
 .Dq no .
+The default is
+.Dq no .
 .It Cm ForwardX11
 Specifies whether X11 connections will be automatically redirected
 over the secure channel and
diff --git a/ssh.c b/ssh.c
index 1cc8dbbf..2934c3a4 100644
--- a/ssh.c
+++ b/ssh.c
@@ -11,7 +11,7 @@
  */
 
 #include "includes.h"
-RCSID("$Id: ssh.c,v 1.32 2000/05/20 05:22:37 damien Exp $");
+RCSID("$Id: ssh.c,v 1.33 2000/05/30 03:44:54 damien Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/dsa.h>
@@ -116,6 +116,7 @@ usage()
 	fprintf(stderr, "Options:\n");
 	fprintf(stderr, "  -l user     Log in using this user name.\n");
 	fprintf(stderr, "  -n          Redirect input from /dev/null.\n");
+	fprintf(stderr, "  -A          Enable authentication agent forwarding.\n");
 	fprintf(stderr, "  -a          Disable authentication agent forwarding.\n");
 #ifdef AFS
 	fprintf(stderr, "  -k          Disable Kerberos ticket and AFS token forwarding.\n");
@@ -315,6 +316,9 @@ main(int ac, char **av)
 		case 'a':
 			options.forward_agent = 0;
 			break;
+		case 'A':
+			options.forward_agent = 1;
+			break;
 #ifdef AFS
 		case 'k':
 			options.kerberos_tgt_passing = 0;
diff --git a/sshconnect2.c b/sshconnect2.c
index 99ffb2c4..0abcf89a 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -28,7 +28,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshconnect2.c,v 1.10 2000/05/08 17:42:25 markus Exp $");
+RCSID("$OpenBSD: sshconnect2.c,v 1.11 2000/05/25 20:45:20 markus Exp $");
 
 #include <openssl/bn.h>
 #include <openssl/rsa.h>
@@ -68,16 +68,12 @@ unsigned char *session_id2 = NULL;
 int session_id2_len = 0;
 
 void
-ssh_kex2(char *host, struct sockaddr *hostaddr)
+ssh_kex_dh(Kex *kex, char *host, struct sockaddr *hostaddr,
+    Buffer *client_kexinit, Buffer *server_kexinit)
 {
-	Kex *kex;
-	char *cprop[PROPOSAL_MAX];
-	char *sprop[PROPOSAL_MAX];
-	Buffer *client_kexinit;
-	Buffer *server_kexinit;
-	int payload_len, dlen;
+	int i;
+	int plen, dlen;
 	unsigned int klen, kout;
-	char *ptr;
 	char *signature = NULL;
 	unsigned int slen;
 	char *server_host_key_blob = NULL;
@@ -86,72 +82,10 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 	DH *dh;
 	BIGNUM *dh_server_pub = 0;
 	BIGNUM *shared_secret = 0;
-	int i;
 	unsigned char *kbuf;
 	unsigned char *hash;
 
-/* KEXINIT */
-
-	debug("Sending KEX init.");
-	if (options.ciphers != NULL) {
-		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
-		myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
-	} else if (options.cipher == SSH_CIPHER_3DES) {
-		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
-		myproposal[PROPOSAL_ENC_ALGS_STOC] =
-		    cipher_name(SSH_CIPHER_3DES_CBC);
-	} else if (options.cipher == SSH_CIPHER_BLOWFISH) {
-		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
-		myproposal[PROPOSAL_ENC_ALGS_STOC] =
-		    cipher_name(SSH_CIPHER_BLOWFISH_CBC);
-	}
-	if (options.compression) {
-		myproposal[PROPOSAL_COMP_ALGS_CTOS] = "zlib";
-		myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib";
-	} else {
-		myproposal[PROPOSAL_COMP_ALGS_CTOS] = "none";
-		myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
-	}
-	for (i = 0; i < PROPOSAL_MAX; i++)
-		cprop[i] = xstrdup(myproposal[i]);
-
-	client_kexinit = kex_init(cprop);
-	packet_start(SSH2_MSG_KEXINIT);
-	packet_put_raw(buffer_ptr(client_kexinit), buffer_len(client_kexinit));	
-	packet_send();
-	packet_write_wait();
-
-	debug("done");
-
-	packet_read_expect(&payload_len, SSH2_MSG_KEXINIT);
-
-	/* save payload for session_id */
-	server_kexinit = xmalloc(sizeof(*server_kexinit));
-	buffer_init(server_kexinit);
-	ptr = packet_get_raw(&payload_len);
-	buffer_append(server_kexinit, ptr, payload_len);
-
-	/* skip cookie */
-	for (i = 0; i < 16; i++)
-		(void) packet_get_char();
-	/* kex init proposal strings */
-	for (i = 0; i < PROPOSAL_MAX; i++) {
-		sprop[i] = packet_get_string(NULL);
-		debug("got kexinit string: %s", sprop[i]);
-	}
-	i = (int) packet_get_char();
-	debug("first kex follow == %d", i);
-	i = packet_get_int();
-	debug("reserved == %d", i);
-	packet_done();
-
-	debug("done read kexinit");
-	kex = kex_choose_conf(cprop, sprop, 0);
-
-/* KEXDH */
-
 	debug("Sending SSH2_MSG_KEXDH_INIT.");
-
 	/* generate and send 'e', client DH public key */
 	dh = dh_new_group1();
 	packet_start(SSH2_MSG_KEXDH_INIT);
@@ -172,7 +106,7 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 
 	debug("Wait SSH2_MSG_KEXDH_REPLY.");
 
-	packet_read_expect(&payload_len, SSH2_MSG_KEXDH_REPLY);
+	packet_read_expect(&plen, SSH2_MSG_KEXDH_REPLY);
 
 	debug("Got SSH2_MSG_KEXDH_REPLY.");
 
@@ -233,10 +167,7 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 	    shared_secret
 	);
 	xfree(server_host_key_blob);
-	buffer_free(client_kexinit);
-	buffer_free(server_kexinit);
-	xfree(client_kexinit);
-	xfree(server_kexinit);
+	DH_free(dh);
 #ifdef DEBUG_KEXDH
 	fprintf(stderr, "hash == ");
 	for (i = 0; i< 20; i++)
@@ -250,16 +181,61 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 	kex_derive_keys(kex, hash, shared_secret);
 	packet_set_kex(kex);
 
-	/* have keys, free DH */
-	DH_free(dh);
-
 	/* save session id */
 	session_id2_len = 20;
 	session_id2 = xmalloc(session_id2_len);
 	memcpy(session_id2, hash, session_id2_len);
+}
+
+void
+ssh_kex2(char *host, struct sockaddr *hostaddr)
+{
+	int i, plen;
+	Kex *kex;
+	Buffer *client_kexinit, *server_kexinit;
+	char *sprop[PROPOSAL_MAX];
+
+	if (options.ciphers != NULL) {
+		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+		myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
+	} else if (options.cipher == SSH_CIPHER_3DES) {
+		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+		myproposal[PROPOSAL_ENC_ALGS_STOC] =
+		    (char *) cipher_name(SSH_CIPHER_3DES_CBC);
+	} else if (options.cipher == SSH_CIPHER_BLOWFISH) {
+		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+		myproposal[PROPOSAL_ENC_ALGS_STOC] =
+		    (char *) cipher_name(SSH_CIPHER_BLOWFISH_CBC);
+	}
+	if (options.compression) {
+		myproposal[PROPOSAL_COMP_ALGS_CTOS] = "zlib";
+		myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib";
+	} else {
+		myproposal[PROPOSAL_COMP_ALGS_CTOS] = "none";
+		myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
+	}
+
+	/* buffers with raw kexinit messages */
+	server_kexinit = xmalloc(sizeof(*server_kexinit));
+	buffer_init(server_kexinit);
+	client_kexinit = kex_init(myproposal);
+
+	/* algorithm negotiation */
+	kex_exchange_kexinit(client_kexinit, server_kexinit, sprop);
+	kex = kex_choose_conf(myproposal, sprop, 0);
+	for (i = 0; i < PROPOSAL_MAX; i++)
+		xfree(sprop[i]);
+
+	/* server authentication and session key agreement */
+	ssh_kex_dh(kex, host, hostaddr, client_kexinit, server_kexinit);
+
+	buffer_free(client_kexinit);
+	buffer_free(server_kexinit);
+	xfree(client_kexinit);
+	xfree(server_kexinit);
 
 	debug("Wait SSH2_MSG_NEWKEYS.");
-	packet_read_expect(&payload_len, SSH2_MSG_NEWKEYS);
+	packet_read_expect(&plen, SSH2_MSG_NEWKEYS);
 	packet_done();
 	debug("GOT SSH2_MSG_NEWKEYS.");
 
@@ -278,6 +254,7 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 #endif
 	debug("done: KEX2.");
 }
+
 /*
  * Authenticate user
  */
diff --git a/sshd.c b/sshd.c
index 39fbcba4..ec860024 100644
--- a/sshd.c
+++ b/sshd.c
@@ -14,7 +14,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.117 2000/05/18 13:27:36 djm Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.118 2000/05/25 20:45:20 markus Exp $");
 
 #include "xmalloc.h"
 #include "rsa.h"
@@ -1159,7 +1159,6 @@ do_ssh2_kex()
 	int payload_len, dlen;
 	int slen;
 	unsigned int klen, kout;
-	char *ptr;
 	unsigned char *signature = NULL;
 	unsigned char *server_host_key_blob = NULL;
 	unsigned int sbloblen;
@@ -1171,7 +1170,6 @@ do_ssh2_kex()
 	unsigned char *hash;
 	Kex *kex;
 	char *cprop[PROPOSAL_MAX];
-	char *sprop[PROPOSAL_MAX];
 
 /* KEXINIT */
 
@@ -1179,46 +1177,15 @@ do_ssh2_kex()
 		myproposal[PROPOSAL_ENC_ALGS_CTOS] =
 		myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
 	}
-
-	debug("Sending KEX init.");
-
-	for (i = 0; i < PROPOSAL_MAX; i++)
-		sprop[i] = xstrdup(myproposal[i]);
-	server_kexinit = kex_init(sprop);
-	packet_start(SSH2_MSG_KEXINIT);
-	packet_put_raw(buffer_ptr(server_kexinit), buffer_len(server_kexinit));	
-	packet_send();
-	packet_write_wait();
-
-	debug("done");
-
-	packet_read_expect(&payload_len, SSH2_MSG_KEXINIT);
-
-	/*
-	 * save raw KEXINIT payload in buffer. this is used during
-	 * computation of the session_id and the session keys.
-	 */
+	server_kexinit = kex_init(myproposal);
 	client_kexinit = xmalloc(sizeof(*client_kexinit));
 	buffer_init(client_kexinit);
-	ptr = packet_get_raw(&payload_len);
-	buffer_append(client_kexinit, ptr, payload_len);