- 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 3037eac38..f8dcd9ce9 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 639c1abbd..4117cb772 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 00f031b8b..967e0b6b8 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 221e03041..199e04264 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 5395ebc3f..7e5c67024 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 ae355a3fc..d474f85c6 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 8b2417972..9611d8951 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 9c5638b07..d7011d7f7 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 05630c766..1aa4fe06d 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 977ed41f6..b08fcfd92 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 4b7404f73..4791857c0 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 d8e9eb0b9..6c1d3763e 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 1cc8dbbf3..2934c3a4a 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 99ffb2c47..0abcf89a0 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 39fbcba40..ec860024b 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);
 
-        /* skip cookie */
-        for (i = 0; i < 16; i++)
-                (void) packet_get_char();
-        /* save kex init proposal strings */
-        for (i = 0; i < PROPOSAL_MAX; i++) {
-                cprop[i] = packet_get_string(NULL);
-                debug("got kexinit string: %s", cprop[i]);
-        }
-
-        i = (int) packet_get_char();
-        debug("first kex follow == %d", i);
-        i = packet_get_int();
-        debug("reserved == %d", i);
-
-        debug("done read kexinit");
-        kex = kex_choose_conf(cprop, sprop, 1);
+        /* algorithm negotiation */
+        kex_exchange_kexinit(server_kexinit, client_kexinit, cprop);
+        kex = kex_choose_conf(cprop, myproposal, 1);
+        for (i = 0; i < PROPOSAL_MAX; i++)
+                xfree(cprop[i]);
 
 /* KEXDH */