- OpenBSD CVS update:

   - [packet.h packet.c]
     ssh2 packet format
   - [packet.h packet.c nchan2.ms nchan.h compat.h compat.c]
     [channels.h channels.c]
     channel layer support for ssh2
   - [kex.h kex.c hmac.h hmac.c dsa.c dsa.h]
     DSA, keyexchange, algorithm agreement for ssh2

17 files changed, 2277 insertions, 166 deletions

diff --git a/ChangeLog b/ChangeLog
index 2beaf7fc..906e09f0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 20000404
  - Add tests for RAND_add function when searching for OpenSSL
+ - OpenBSD CVS update:
+   - [packet.h packet.c]
+     ssh2 packet format
+   - [packet.h packet.c nchan2.ms nchan.h compat.h compat.c]
+     [channels.h channels.c]
+     channel layer support for ssh2
+   - [kex.h kex.c hmac.h hmac.c dsa.c dsa.h]
+     DSA, keyexchange, algorithm agreement for ssh2
 
 20000403
  - Wrote entropy collection routines for systems that lack /dev/random
diff --git a/Makefile.in b/Makefile.in
index 89b40848..bb08b53b 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -31,7 +31,7 @@ LDFLAGS=-L. @LDFLAGS@
 
 TARGETS=ssh sshd ssh-add ssh-keygen ssh-agent scp $(EXTRA_TARGETS)
 
-LIBOBJS= atomicio.o authfd.o authfile.o bsd-bindresvport.o bsd-daemon.o bsd-misc.o bsd-mktemp.o bsd-rresvport.o bsd-setenv.o bsd-snprintf.o bsd-strlcat.o bsd-strlcpy.o bufaux.o buffer.o canohost.o channels.o cipher.o compat.o compress.o crc32.o deattack.o dispatch.o fake-getaddrinfo.o fake-getnameinfo.o fingerprint.o hostfile.o key.o log.o match.o mpaux.o nchan.o packet.o radix.o entropy.o readpass.o rsa.o tildexpand.o ttymodes.o uidswap.o xmalloc.o 
+LIBOBJS= atomicio.o authfd.o authfile.o bsd-bindresvport.o bsd-daemon.o bsd-misc.o bsd-mktemp.o bsd-rresvport.o bsd-setenv.o bsd-snprintf.o bsd-strlcat.o bsd-strlcpy.o bufaux.o buffer.o canohost.o channels.o cipher.o compat.o compress.o crc32.o deattack.o dispatch.o dsa.o fake-getaddrinfo.o fake-getnameinfo.o fingerprint.o hmac.o hostfile.o key.o kex.o log.o match.o mpaux.o nchan.o packet.o radix.o entropy.o readpass.o rsa.o tildexpand.o ttymodes.o uidswap.o xmalloc.o 
 
 SSHOBJS= ssh.o sshconnect.o log-client.o readconf.o clientloop.o
 
diff --git a/channels.c b/channels.c
index b87ff9f4..18f667f6 100644
--- a/channels.c
+++ b/channels.c
@@ -13,10 +13,11 @@
  * There is also code for initiating connection forwarding for X11 connections,
  * arbitrary tcp/ip connections, and the authentication agent connection.
  * 
+ * SSH2 support added by Markus Friedl.
  */
 
 #include "includes.h"
-RCSID("$Id: channels.c,v 1.20 2000/04/01 01:09:23 damien Exp $");
+RCSID("$Id: channels.c,v 1.21 2000/04/04 04:39:00 damien Exp $");
 
 #include "ssh.h"
 #include "packet.h"
@@ -31,6 +32,8 @@ RCSID("$Id: channels.c,v 1.20 2000/04/01 01:09:23 damien Exp $");
 #include "nchan.h"
 #include "compat.h"
 
+#include "ssh2.h"
+
 /* Maximum number of fake X11 displays to try. */
 #define MAX_DISPLAYS  1000
 
@@ -165,6 +168,7 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd,
 
 	/* Do initial allocation if this is the first call. */
 	if (channels_alloc == 0) {
+		chan_init();
 		channels_alloc = 10;
 		channels = xmalloc(channels_alloc * sizeof(Channel));
 		for (i = 0; i < channels_alloc; i++)
@@ -237,9 +241,28 @@ channel_free(int id)
 	if (c == NULL)
 		packet_disconnect("channel free: bad local channel %d", id);
 	debug("channel_free: channel %d: status: %s", id, channel_open_message());
+	if (c->dettach_user != NULL) {
+		debug("channel_free: channel %d: dettaching channel user", id);
+		c->dettach_user(c->self, NULL);
+	}
 	if (c->sock != -1) {
 		shutdown(c->sock, SHUT_RDWR);
 		close(c->sock);
+		c->sock = -1;
+	}
+	if (compat20) {
+		if (c->rfd != -1) {
+			close(c->rfd);
+			c->rfd = -1;
+		}
+		if (c->wfd != -1) {
+			close(c->wfd);
+			c->wfd = -1;
+		}
+		if (c->efd != -1) {
+			close(c->efd);
+			c->efd = -1;
+		}
 	}
 	buffer_free(&c->input);
 	buffer_free(&c->output);
@@ -296,6 +319,32 @@ channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
 }
 
 void
+channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	if (c->istate == CHAN_INPUT_OPEN &&
+	    c->remote_window > 0 &&
+	    buffer_len(&c->input) < c->remote_window)
+		FD_SET(c->rfd, readset);
+	if (c->ostate == CHAN_OUTPUT_OPEN ||
+	    c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
+		if (buffer_len(&c->output) > 0) {
+			FD_SET(c->wfd, writeset);
+		} else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
+			chan_obuf_empty(c);
+		}
+	}
+	/** XXX check close conditions, too */
+	if (c->efd != -1) {
+		if (c->extended_usage == CHAN_EXTENDED_WRITE &&
+		    buffer_len(&c->extended) > 0)
+			FD_SET(c->efd, writeset);
+		else if (c->extended_usage == CHAN_EXTENDED_READ &&
+		    buffer_len(&c->extended) < c->remote_window)
+			FD_SET(c->efd, readset);
+	}
+}
+
+void
 channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
 {
 	if (buffer_len(&c->input) == 0) {
@@ -483,15 +532,27 @@ channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
 		    SSH_CHANNEL_OPENING, newsock, newsock, -1,
 		    c->local_window_max, c->local_maxpacket,
 		    0, xstrdup(buf));
-
-		packet_start(SSH_MSG_PORT_OPEN);
-		packet_put_int(newch);
-		packet_put_string(c->path, strlen(c->path));
-		packet_put_int(c->host_port);
-		if (have_hostname_in_open) {
-			packet_put_string(buf, strlen(buf));
+		if (compat20) {
+			packet_start(SSH2_MSG_CHANNEL_OPEN);
+			packet_put_cstring("direct-tcpip");
+			packet_put_int(newch);
+			packet_put_int(c->local_window_max);
+			packet_put_int(c->local_maxpacket);
+			packet_put_string(c->path, strlen(c->path));
+			packet_put_int(c->host_port);
+			packet_put_cstring(remote_hostname);
+			packet_put_int(remote_port);
+			packet_send();
+		} else {
+			packet_start(SSH_MSG_PORT_OPEN);
+			packet_put_int(newch);
+			packet_put_string(c->path, strlen(c->path));
+			packet_put_int(c->host_port);
+			if (have_hostname_in_open) {
+				packet_put_string(buf, strlen(buf));
+			}
+			packet_send();
 		}
-		packet_send();
 		xfree(remote_hostname);
 	}
 }
@@ -569,6 +630,56 @@ channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
 			return -1;
 		}
 		buffer_consume(&c->output, len);
+		if (compat20 && len > 0) {
+			c->local_consumed += len;
+		}
+	}
+	return 1;
+}
+int
+channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	char buf[16*1024];
+	int len;
+
+	if (c->efd != -1) {
+		if (c->extended_usage == CHAN_EXTENDED_WRITE &&
+		    FD_ISSET(c->efd, writeset) &&
+		    buffer_len(&c->extended) > 0) {
+			len = write(c->efd, buffer_ptr(&c->extended),
+			    buffer_len(&c->extended));
+			debug("channel %d: written %d to efd %d",
+			    c->self, len, c->efd);
+			if (len > 0) {
+				buffer_consume(&c->extended, len);
+				c->local_consumed += len;
+			}
+		} else if (c->extended_usage == CHAN_EXTENDED_READ &&
+		    FD_ISSET(c->efd, readset)) {
+			len = read(c->efd, buf, sizeof(buf));
+			debug("channel %d: read %d from efd %d",
+			     c->self, len, c->efd);
+			if (len > 0)
+				buffer_append(&c->extended, buf, len);
+		}
+	}
+	return 1;
+}
+int
+channel_check_window(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	if (!(c->flags & CHAN_CLOSE_SENT) &&
+	    c->local_window < c->local_window_max/2 &&
+	    c->local_consumed > 0) {
+		packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+		packet_put_int(c->remote_id);
+		packet_put_int(c->local_consumed);
+		packet_send();
+		debug("channel %d: window %d sent adjust %d",
+		    c->self, c->local_window,
+		    c->local_consumed);
+		c->local_window += c->local_consumed;
+		c->local_consumed = 0;
 	}
 	return 1;
 }
@@ -581,6 +692,15 @@ channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
 }
 
 void
+channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	channel_handle_rfd(c, readset, writeset);
+	channel_handle_wfd(c, readset, writeset);
+	channel_handle_efd(c, readset, writeset);
+	channel_check_window(c, readset, writeset);
+}
+
+void
 channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
 {
 	int len;
@@ -596,6 +716,16 @@ channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
 }
 
 void
+channel_handler_init_20(void)
+{
+	channel_pre[SSH_CHANNEL_OPEN] =			&channel_pre_open_20;
+	channel_pre[SSH_CHANNEL_PORT_LISTENER] =	&channel_pre_listener;
+
+	channel_post[SSH_CHANNEL_OPEN] =		&channel_post_open_2;
+	channel_post[SSH_CHANNEL_PORT_LISTENER] =	&channel_post_port_listener;
+}
+
+void
 channel_handler_init_13(void)
 {
 	channel_pre[SSH_CHANNEL_OPEN] =			&channel_pre_open_13;
@@ -636,7 +766,9 @@ channel_handler_init(void)
 		channel_pre[i] = NULL;
 		channel_post[i] = NULL;
 	}
-	if (compat13)
+	if (compat20)
+		channel_handler_init_20();
+	else if (compat13)
 		channel_handler_init_13();
 	else
 		channel_handler_init_15();
@@ -660,8 +792,7 @@ channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
 		if (ftab[c->type] == NULL)
 			continue;
 		(*ftab[c->type])(c, readset, writeset);
-		if (!compat13)
-			chan_delete_if_full_closed(c);
+		chan_delete_if_full_closed(c);
 	}
 }
 
@@ -700,27 +831,39 @@ channel_output_poll()
 			    c->istate != CHAN_INPUT_WAIT_DRAIN)
 				continue;
 		}
+		if (compat20 && (c->flags & CHAN_CLOSE_SENT)) {
+			debug("channel: %d: no data after CLOSE", c->self);
+			continue;
+		}
 
 		/* Get the amount of buffered data for this channel. */
 		len = buffer_len(&c->input);
 		if (len > 0) {
 			/* Send some data for the other side over the secure connection. */
-			if (packet_is_interactive()) {
-				if (len > 1024)
-					len = 512;
+			if (compat20) {
+				if (len > c->remote_window)
+					len = c->remote_window;
+				if (len > c->remote_maxpacket)
+					len = c->remote_maxpacket;
 			} else {
-				/* Keep the packets at reasonable size. */
-				if (len > packet_get_maxsize())
-					len = packet_get_maxsize()/2;
+				if (packet_is_interactive()) {
+					if (len > 1024)
+						len = 512;
+				} else {
+					/* Keep the packets at reasonable size. */
+					if (len > packet_get_maxsize()/2)
+						len = packet_get_maxsize()/2;
+				}
 			}
 			if (len > 0) {
-				packet_start(SSH_MSG_CHANNEL_DATA);
+				packet_start(compat20 ?
+				    SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
 				packet_put_int(c->remote_id);
 				packet_put_string(buffer_ptr(&c->input), len);
 				packet_send();
 				buffer_consume(&c->input, len);
 				c->remote_window -= len;
-debug("channel %d: send data len %d", c->self, len);
+				debug("channel %d: send data len %d", c->self, len);
 			}
 		} else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
 			if (compat13)
@@ -731,6 +874,23 @@ debug("channel %d: send data len %d", c->self, len);
 			 */
 			chan_ibuf_empty(c);
 		}
+		/* Send extended data, i.e. stderr */
+		if (compat20 &&
+		    c->remote_window > 0 &&
+		    (len = buffer_len(&c->extended)) > 0 &&
+		    c->extended_usage == CHAN_EXTENDED_READ) {
+			if (len > c->remote_window)
+				len = c->remote_window;
+			if (len > c->remote_maxpacket)
+				len = c->remote_maxpacket;
+			packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
+			packet_put_int(c->remote_id);
+			packet_put_int(SSH2_EXTENDED_DATA_STDERR);
+			packet_put_string(buffer_ptr(&c->extended), len);
+			packet_send();
+			buffer_consume(&c->extended, len);
+			c->remote_window -= len;
+		}
 	}
 }
 
@@ -766,10 +926,63 @@ channel_input_data(int type, int plen)
 	/* Get the data. */
 	data = packet_get_string(&data_len);
 
-	packet_integrity_check(plen, 4 + 4 + data_len, SSH_MSG_CHANNEL_DATA);
+	if (compat20){
+		if (data_len > c->local_maxpacket) {
+			log("channel %d: rcvd big packet %d, maxpack %d",
+			    c->self, data_len, c->local_maxpacket);
+		}
+		if (data_len > c->local_window) {
+			log("channel %d: rcvd too much data %d, win %d",
+			    c->self, data_len, c->local_window);
+			xfree(data);
+			return;
+		}
+		c->local_window -= data_len;
+	}else{
+		packet_integrity_check(plen, 4 + 4 + data_len, type);
+	}
 	buffer_append(&c->output, data, data_len);
 	xfree(data);
 }
+void 
+channel_input_extended_data(int type, int plen)
+{
+	int id;
+	int tcode;
+	char *data;
+	unsigned int data_len;
+	Channel *c;
+
+	/* Get the channel number and verify it. */
+	id = packet_get_int();
+	c = channel_lookup(id);
+
+	if (c == NULL)
+		packet_disconnect("Received extended_data for bad channel %d.", id);
+	if (c->type != SSH_CHANNEL_OPEN) {
+		log("channel %d: ext data for non open", id);
+		return;
+	}
+	tcode = packet_get_int();
+	if (c->efd == -1 ||
+	    c->extended_usage != CHAN_EXTENDED_WRITE ||
+	    tcode != SSH2_EXTENDED_DATA_STDERR) {
+		log("channel %d: bad ext data", c->self);
+		return;
+	}
+	data = packet_get_string(&data_len);
+	if (data_len > c->local_window) {
+		log("channel %d: rcvd too much extended_data %d, win %d",
+		    c->self, data_len, c->local_window);
+		xfree(data);
+		return;
+	}
+	debug("channel %d: rcvd ext data %d", c->self, data_len);
+	c->local_window -= data_len;
+	buffer_append(&c->extended, data, data_len);
+	xfree(data);
+}
+
 
 /*
  * Returns true if no channel has too much buffered data, and false if one or
@@ -785,7 +998,7 @@ channel_not_very_much_buffered_data()
 	for (i = 0; i < channels_alloc; i++) {
 		c = &channels[i];
 		if (c->type == SSH_CHANNEL_OPEN) {
-			if (buffer_len(&c->input) > packet_get_maxsize()) {
+			if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) {
 				debug("channel %d: big input buffer %d",
 				    c->self, buffer_len(&c->input));
 				return 0;
@@ -886,7 +1099,8 @@ channel_input_open_confirmation(int type, int plen)
 	int id, remote_id;
 	Channel *c;
 
-	packet_integrity_check(plen, 4 + 4, type);
+	if (!compat20)
+		packet_integrity_check(plen, 4 + 4, type);
 
 	id = packet_get_int();
 	c = channel_lookup(id);
@@ -898,6 +1112,18 @@ channel_input_open_confirmation(int type, int plen)
 	/* Record the remote channel number and mark that the channel is now open. */
 	c->remote_id = remote_id;
 	c->type = SSH_CHANNEL_OPEN;
+
+	if (compat20) {
+		c->remote_window = packet_get_int();
+		c->remote_maxpacket = packet_get_int();
+		if (c->cb_fn != NULL && c->cb_event == type) {
+			debug("callback start");
+			c->cb_fn(c->self, c->cb_arg);
+			debug("callback done");
+		}
+		debug("channel %d: open confirm rwindow %d rmax %d", c->self,
+		    c->remote_window, c->remote_maxpacket);
+	}
 }
 
 void 
@@ -906,7 +1132,8 @@ channel_input_open_failure(int type, int plen)
 	int id;
 	Channel *c;
 
-	packet_integrity_check(plen, 4, type);
+	if (!compat20)
+		packet_integrity_check(plen, 4, type);
 
 	id = packet_get_int();
 	c = channel_lookup(id);
@@ -914,11 +1141,64 @@ channel_input_open_failure(int type, int plen)
 	if (c==NULL || c->type != SSH_CHANNEL_OPENING)
 		packet_disconnect("Received open failure for "
 		    "non-opening channel %d.", id);
-
+	if (compat20) {
+		int reason = packet_get_int();
+		char *msg  = packet_get_string(NULL);
+		log("channel_open_failure: %d: reason %d: %s", id, reason, msg);
+		xfree(msg);
+	}
 	/* Free the channel.  This will also close the socket. */
 	channel_free(id);
 }
 
+void
+channel_input_channel_request(int type, int plen)
+{
+	int id;
+	Channel *c;
+
+	id = packet_get_int();
+	c = channel_lookup(id);
+
+	if (c == NULL ||
+	    (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL))
+		packet_disconnect("Received request for "
+		    "non-open channel %d.", id);
+	if (c->cb_fn != NULL && c->cb_event == type) {
+		debug("callback start");
+		c->cb_fn(c->self, c->cb_arg);
+		debug("callback done");
+	} else {
+		char *service = packet_get_string(NULL);
+		debug("channel: %d rcvd request for %s", c->self, service);
+debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
+		xfree(service);
+	}
+}
+
+void 
+channel_input_window_adjust(int type, int plen)
+{
+	Channel *c;
+	int id, adjust;
+
+	if (!compat20)
+		return;
+
+	/* Get the channel number and verify it. */
+	id = packet_get_int();
+	c = channel_lookup(id);
+
+	if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
+		log("Received window adjust for "
+		    "non-open channel %d.", id);
+		return;
+	}
+	adjust = packet_get_int();
+	debug("channel %d: rcvd adjust %d", id, adjust);
+	c->remote_window += adjust;
+}
+
 /*
  * Stops listening for channels, and removes any unix domain sockets that we
  * might have.
@@ -983,6 +1263,10 @@ channel_still_open()
 		case SSH_CHANNEL_CLOSED:
 		case SSH_CHANNEL_AUTH_SOCKET:
 			continue;
+		case SSH_CHANNEL_LARVAL:
+			if (!compat20)
+				fatal("cannot happen: SSH_CHANNEL_LARVAL");
+			continue;
 		case SSH_CHANNEL_OPENING:
 		case SSH_CHANNEL_OPEN:
 		case SSH_CHANNEL_X11_OPEN:
@@ -1024,6 +1308,7 @@ channel_open_message()
 		case SSH_CHANNEL_CLOSED:
 		case SSH_CHANNEL_AUTH_SOCKET:
 			continue;
+		case SSH_CHANNEL_LARVAL:
 		case SSH_CHANNEL_OPENING:
 		case SSH_CHANNEL_OPEN:
 		case SSH_CHANNEL_X11_OPEN:
@@ -1156,17 +1441,26 @@ channel_request_remote_forwarding(u_short listen_port, const char *host_to_conne
 	num_permitted_opens++;
 
 	/* Send the forward request to the remote side. */
-	packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
-	packet_put_int(port_to_connect);
-	packet_put_string(host_to_connect, strlen(host_to_connect));
-	packet_put_int(listen_port);
-	packet_send();
-	packet_write_wait();
-	/*
-	 * Wait for response from the remote side.  It will send a disconnect
-	 * message on failure, and we will never see it here.
-	 */
-	packet_read_expect(&payload_len, SSH_SMSG_SUCCESS);
+	if (compat20) {
+		const char *address_to_bind = "0.0.0.0";
+		packet_start(SSH2_MSG_GLOBAL_REQUEST);
+		packet_put_cstring("tcpip-forward");
+		packet_put_char(0);			/* boolean: want reply */
+		packet_put_cstring(address_to_bind);
+		packet_put_int(listen_port);
+	} else {
+		packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
+		packet_put_int(port_to_connect);
+		packet_put_cstring(host_to_connect);
+		packet_put_int(listen_port);
+		packet_send();
+		packet_write_wait();
+		/*
+		 * Wait for response from the remote side.  It will send a disconnect
+		 * message on failure, and we will never see it here.
+		 */
+		packet_read_expect(&payload_len, SSH_SMSG_SUCCESS);
+	}
 }
 
 /*
@@ -1839,3 +2133,97 @@ auth_input_open_request(int type, int plen)
 	packet_put_int(newch);
 	packet_send();
 }
+
+void
+channel_open(int id)
+{
+	Channel *c = channel_lookup(id);
+	if (c == NULL) {
+		log("channel_open: %d: bad id", id);
+		return;
+	}
+	packet_start(SSH2_MSG_CHANNEL_OPEN);
+	packet_put_cstring(c->ctype);
+	packet_put_int(c->self);
+	packet_put_int(c->local_window);
+	packet_put_int(c->local_maxpacket);
+	packet_send();
+	debug("channel open %d", id);
+}
+void
+channel_request(int id, char *service, int wantconfirm)
+{
+	channel_request_start(id, service, wantconfirm);
+	packet_send();
+	debug("channel request %d: %s", id, service) ;
+}
+void
+channel_request_start(int id, char *service, int wantconfirm)
+{
+	Channel *c = channel_lookup(id);
+	if (c == NULL) {
+		log("channel_request: %d: bad id", id);
+		return;
+	}
+	packet_start(SSH2_MSG_CHANNEL_REQUEST);
+	packet_put_int(c->remote_id);
+	packet_put_cstring(service);
+	packet_put_char(wantconfirm);
+}
+void
+channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg)
+{
+	Channel *c = channel_lookup(id);
+	if (c == NULL) {
+		log("channel_register_callback: %d: bad id", id);
+		return;
+	}
+	c->cb_event = mtype;
+	c->cb_fn = fn;
+	c->cb_arg = arg;
+}
+void
+channel_register_cleanup(int id, channel_callback_fn *fn)
+{
+	Channel *c = channel_lookup(id);
+	if (c == NULL) {
+		log("channel_register_cleanup: %d: bad id", id);
+		return;
+	}
+	c->dettach_user = fn;
+}
+void
+channel_cancel_cleanup(int id)
+{
+	Channel *c = channel_lookup(id);
+	if (c == NULL) {
+		log("channel_cancel_cleanup: %d: bad id", id);
+		return;
+	}
+	c->dettach_user = NULL;
+}
+
+void
+channel_set_fds(int id, int rfd, int wfd, int efd, int extusage)
+{
+	Channel *c = channel_lookup(id);
+	if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
+		fatal("channel_activate for non-larval channel %d.", id);
+	if (rfd > channel_max_fd_value)
+		channel_max_fd_value = rfd;
+	if (wfd > channel_max_fd_value)
+		channel_max_fd_value = wfd;
+	if (efd > channel_max_fd_value)
+		channel_max_fd_value = efd;
+	c->type = SSH_CHANNEL_OPEN;
+	c->rfd = rfd;
+	c->wfd = wfd;
+	c->efd = efd;
+	c->extended_usage = extusage;
+	/* XXX window size? */
+	c->local_window = c->local_window_max = c->local_maxpacket/2;
+	packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
+	packet_put_int(c->remote_id);
+	packet_put_int(c->local_window);
+	packet_send();
+}
diff --git a/channels.h b/channels.h
index 73ff5a59..33af09d9 100644
--- a/channels.h
+++ b/channels.h
@@ -1,4 +1,4 @@
-/* RCSID("$Id: channels.h,v 1.5 2000/04/01 01:09:23 damien Exp $"); */
+/* RCSID("$Id: channels.h,v 1.6 2000/04/04 04:39:01 damien Exp $"); */
 
 #ifndef CHANNELS_H
 #define CHANNELS_H
@@ -30,6 +30,7 @@ typedef struct Channel {
 	/* peer can be reached over encrypted connection, via packet-sent */
 	int     istate;		/* input from channel (state of receive half) */
 	int     ostate;		/* output to channel  (state of transmit half) */
+	int     flags;		/* close sent/rcvd */
 	int     rfd;		/* read fd */
 	int     wfd;		/* write fd */
 	int     efd;		/* extended fd */
@@ -66,21 +67,30 @@ typedef struct Channel {
 #define CHAN_EXTENDED_READ		1
 #define CHAN_EXTENDED_WRITE		2
 
+void	channel_set_fds(int id, int rfd, int wfd, int efd, int extusage);
 void	channel_open(int id);
+void	channel_request(int id, char *service, int wantconfirm);
+void	channel_request_start(int id, char *service, int wantconfirm);
+void	channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg);
+void	channel_register_cleanup(int id, channel_callback_fn *fn);
+void	channel_cancel_cleanup(int id);
 Channel	*channel_lookup(int id);
 
 int
 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
     int window, int maxpack, int extended_usage, char *remote_name);
 
+void	channel_input_channel_request(int type, int plen);
 void	channel_input_close(int type, int plen);
 void	channel_input_close_confirmation(int type, int plen);
 void	channel_input_data(int type, int plen);
+void	channel_input_extended_data(int type, int plen);
 void	channel_input_ieof(int type, int plen);
 void	channel_input_oclose(int type, int plen);
 void	channel_input_open_confirmation(int type, int plen);
 void	channel_input_open_failure(int type, int plen);
 void	channel_input_port_open(int type, int plen);
+void	channel_input_window_adjust(int type, int plen);
 void	channel_input_open(int type, int plen);
 
 /* Sets specific protocol options. */
@@ -218,4 +228,7 @@ void    auth_input_request_forwarding(struct passwd * pw);
 /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
 void    auth_input_open_request(int type, int plen);
 
+/* XXX */
+int	channel_connect_to(const char *host, u_short host_port);
+
 #endif
diff --git a/compat.c b/compat.c
index d39a3d6f..3ecf7101 100644
--- a/compat.c
+++ b/compat.c
@@ -28,15 +28,46 @@
  */
 
 #include "includes.h"
-RCSID("$Id: compat.c,v 1.3 1999/11/25 00:54:59 damien Exp $");
+RCSID("$Id: compat.c,v 1.4 2000/04/04 04:39:01 damien Exp $");
 
 #include "ssh.h"
+#include "packet.h"
 
 int compat13 = 0;
+int compat20 = 0;
+int datafellows = 0;
 
 void 
+enable_compat20(void)
+{
+	fatal("protocol 2.0 not implemented");
+}
+void 
 enable_compat13(void)
 {
 	verbose("Enabling compatibility mode for protocol 1.3");
 	compat13 = 1;
 }
+/* datafellows bug compatibility */
+void
+compat_datafellows(const char *version)
+{
+	int i;
+	size_t len;
+	static const char *check[] = {
+		"2.0.1",
+		"2.1.0.beta.9",
+		"2.1.0.pre.3",
+		"2.1.0.public.beta.1",
+		NULL
+	};
+	for (i = 0; check[i]; i++) {
+		len = strlen(check[i]);
+		if (strlen(version) >= len &&
+		   (strncmp(version, check[i], len) == 0)) {
+			log("datafellows: %.200s", version);
+			datafellows = 1;
+			return;
+		}
+	}
+}
diff --git a/compat.h b/compat.h
index 4f53607f..4247f53b 100644
--- a/compat.h
+++ b/compat.h
@@ -26,10 +26,14 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
-/* RCSID("$Id: compat.h,v 1.3 1999/11/25 00:54:59 damien Exp $"); */
+/* RCSID("$Id: compat.h,v 1.4 2000/04/04 04:39:01 damien Exp $"); */
 
 #ifndef COMPAT_H
 #define COMPAT_H
 void    enable_compat13(void);
+void    enable_compat20(void);
+void    compat_datafellows(const char *s);
 extern int compat13;
+extern int compat20;
+extern int datafellows;
 #endif
diff --git a/dsa.c b/dsa.c
new file mode 100644
index 00000000..99d8ceaf
--- /dev/null
+++ b/dsa.c
@@ -0,0 +1,309 @@
+/*
+ * Copyright (c) 2000 Markus Friedl.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by Markus Friedl.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+RCSID("$Id: dsa.c,v 1.1 2000/04/03 20:06:14 markus Exp $");
+
+#include "ssh.h"
+#include "xmalloc.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "compat.h"
+
+#if HAVE_OPENSSL
+# include <openssl/bn.h>
+# include <openssl/dh.h>
+# include <openssl/rsa.h>
+# include <openssl/dsa.h>
+# include <openssl/evp.h>
+# include <openssl/bio.h>
+# include <openssl/pem.h>
+#endif /* HAVE_OPENSSL */
+#if HAVE_SSL
+# include <ssl/bn.h>
+# include <ssl/dh.h>
+# include <ssl/rsa.h>
+# include <ssl/dsa.h>
+# include <ssl/evp.h>
+# include <ssl/bio.h>
+# include <ssl/pem.h>
+#endif /* HAVE_SSL */
+
+#include <ssl/hmac.h>
+#include "kex.h"
+#include "key.h"
+
+#define INTBLOB_LEN	20
+#define SIGBLOB_LEN	(2*INTBLOB_LEN)
+
+Key *
+dsa_serverkey_from_blob(
+    char *serverhostkey, int serverhostkeylen)
+{
+	Buffer b;
+	char *ktype;
+	int rlen;
+	DSA *dsa;
+	Key *key;
+
+	/* fetch & parse DSA/DSS pubkey */
+	key = key_new(KEY_DSA);
+	dsa = key->dsa;
+	buffer_init(&b);
+	buffer_append(&b, serverhostkey, serverhostkeylen);
+	ktype = buffer_get_string(&b, NULL);
+	if (strcmp(KEX_DSS, ktype) != 0) {
+		log("dsa_serverkey_from_blob: cannot handle type  %s", ktype);
+		key_free(key);
+		return NULL;
+	}
+	buffer_get_bignum2(&b, dsa->p);
+	buffer_get_bignum2(&b, dsa->q);
+	buffer_get_bignum2(&b, dsa->g);
+	buffer_get_bignum2(&b, dsa->pub_key);
+	rlen = buffer_len(&b);
+	if(rlen != 0)
+		log("dsa_serverkey_from_blob: remaining bytes in serverhostkey %d", rlen);
+	buffer_free(&b);
+
+	log("keytype %s", ktype);
+#ifdef DEBUG_DSS
+	DSA_print_fp(stderr, dsa, 8);
+#endif
+	return key;
+}
+DSA *
+dsa_load_private(char *filename)
+{
+	DSA *dsa;
+	BIO *in;
+
+	in = BIO_new(BIO_s_file());
+	if (in == NULL)
+		fatal("BIO_new failed");
+	if (BIO_read_filename(in, filename) <= 0) 
+		fatal("BIO_read failed %s: %s", filename, strerror(errno));
+	fprintf(stderr, "read DSA private key\n");
+	dsa = PEM_read_bio_DSAPrivateKey(in,NULL,NULL,NULL);
+	if (dsa == NULL)
+		fatal("PEM_read_bio_DSAPrivateKey failed %s", filename);
+	BIO_free(in);
+	return dsa;
+}
+Key *
+dsa_get_serverkey(char *filename)
+{
+	Key *k = key_new(KEY_EMPTY);
+	k->type = KEY_DSA;
+	k->dsa = dsa_load_private(filename);
+#ifdef DEBUG_DSS
+	DSA_print_fp(stderr, dsa, 8);
+#endif
+	return k;
+}
+int
+dsa_make_serverkey_blob(Key *key, unsigned char **blobp, unsigned int *lenp)
+{
+	Buffer b;
+	int len;
+	unsigned char *buf;
+
+	if (key == NULL || key->type != KEY_DSA)
+		return 0;
+	buffer_init(&b);
+	buffer_put_cstring(&b, KEX_DSS);
+	buffer_put_bignum2(&b, key->dsa->p);
+	buffer_put_bignum2(&b, key->dsa->q);
+	buffer_put_bignum2(&b, key->dsa->g);
+	buffer_put_bignum2(&b, key->dsa->pub_key);
+	len = buffer_len(&b);
+	buf = xmalloc(len);
+	memcpy(buf, buffer_ptr(&b), len);
+	memset(buffer_ptr(&b), 0, len);
+	buffer_free(&b);
+	if (lenp != NULL)
+		*lenp = len;
+	if (blobp != NULL)
+		*blobp = buf;
+	return len;
+}
+int
+dsa_sign(
+    Key *key,
+    unsigned char **sigp, int *lenp,
+    unsigned char *hash, int hlen)
+{
+	unsigned char *digest;
+	unsigned char *ret;
+	DSA_SIG *sig;
+	EVP_MD *evp_md = EVP_sha1();
+	EVP_MD_CTX md;
+	unsigned int rlen;
+	unsigned int slen;
+	unsigned int len;
+	unsigned char sigblob[SIGBLOB_LEN];
+	Buffer b;
+
+	if (key == NULL || key->type != KEY_DSA || key->dsa == NULL) {
+		log("dsa_sign: no DSA key");
+		return -1;
+	}
+	digest = xmalloc(evp_md->md_size);
+	EVP_DigestInit(&md, evp_md);
+	EVP_DigestUpdate(&md, hash, hlen);
+	EVP_DigestFinal(&md, digest, NULL);
+
+	sig = DSA_do_sign(digest, evp_md->md_size, key->dsa);
+
+        rlen = BN_num_bytes(sig->r);
+        slen = BN_num_bytes(sig->s);
+        if (rlen > INTBLOB_LEN || slen > INTBLOB_LEN) {
+		log("bad sig size %d %d", rlen, slen);
+		DSA_SIG_free(sig);
+		return -1;
+	}
+	log("sig size %d %d", rlen, slen);
+
+	memset(sigblob, 0, SIGBLOB_LEN);
+	BN_bn2bin(sig->r, sigblob+ SIGBLOB_LEN - INTBLOB_LEN - rlen);
+	BN_bn2bin(sig->s, sigblob+ SIGBLOB_LEN - slen);
+	DSA_SIG_free(sig);
+
+	if (datafellows) {
+		log("datafellows");
+		ret = xmalloc(SIGBLOB_LEN);
+		memcpy(ret, sigblob, SIGBLOB_LEN);
+		if (lenp != NULL)
+			*lenp = SIGBLOB_LEN;
+		if (sigp != NULL)
+			*sigp = ret;
+	} else {
+		/* ietf-drafts */
+		buffer_init(&b);
+		buffer_put_cstring(&b, KEX_DSS);
+		buffer_put_string(&b, sigblob, SIGBLOB_LEN);
+		len = buffer_len(&b);
+		ret = xmalloc(len);
+		memcpy(ret, buffer_ptr(&b), len);
+		buffer_free(&b);
+		if (lenp != NULL)
+			*lenp = len;
+		if (sigp != NULL)
+			*sigp = ret;
+	}
+	return 0;
+}
+int
+dsa_verify(
+    Key *key,
+    unsigned char *signature, int signaturelen,
+    unsigned char *hash, int hlen)
+{
+	Buffer b;
+	unsigned char *digest;
+	DSA_SIG *sig;
+	EVP_MD *evp_md = EVP_sha1();
+	EVP_MD_CTX md;
+	char *ktype;
+	unsigned char *sigblob;
+	char *txt;
+	unsigned int len;
+	int rlen;
+	int ret;
+
+	if (key == NULL || key->type != KEY_DSA || key->dsa == NULL) {
+		log("dsa_verify: no DSA key");
+		return -1;
+	}
+
+	if (datafellows && signaturelen != SIGBLOB_LEN) {
+		log("heh? datafellows ssh2 complies with ietf-drafts????");
+		datafellows = 0;
+	}
+
+	log("len %d datafellows %d", signaturelen, datafellows);
+
+	/* fetch signature */
+	if (datafellows) {
+		sigblob = signature;
+		len = signaturelen;
+	} else {
+		/* ietf-drafts */
+		buffer_init(&b);
+		buffer_append(&b, (char *) signature, signaturelen);
+		ktype = buffer_get_string(&b, NULL);
+		sigblob = (unsigned char *)buffer_get_string(&b, &len);
+		rlen = buffer_len(&b);
+		if(rlen != 0)
+			log("remaining bytes in signature %d", rlen);
+		buffer_free(&b);
+	}
+
+	if (len != SIGBLOB_LEN) {
+		fatal("bad sigbloblen %d != SIGBLOB_LEN", len);
+	}
+
+	/* parse signature */
+	sig = DSA_SIG_new();
+	sig->r = BN_new();
+	sig->s = BN_new();
+	BN_bin2bn(sigblob, INTBLOB_LEN, sig->r);
+	BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s);
+	if (!datafellows) {
+		memset(sigblob, 0, len);
+		xfree(sigblob);
+	}
+	
+	/* sha1 the signed data (== session_id == hash) */
+	digest = xmalloc(evp_md->md_size);
+	EVP_DigestInit(&md, evp_md);
+	EVP_DigestUpdate(&md, hash, hlen);
+	EVP_DigestFinal(&md, digest, NULL);
+
+	ret = DSA_do_verify(digest, evp_md->md_size, sig, key->dsa);
+
+	memset(digest, 0, evp_md->md_size);
+	xfree(digest);
+	DSA_SIG_free(sig);
+
+	switch (ret) {
+	case 1:
+		txt = "correct";
+		break;
+	case 0:
+		txt = "incorrect";
+		break;
+	case -1:
+	default:
+		txt = "error";
+		break;
+	}
+	log("dsa_verify: signature %s", txt);
+	return ret;
+}
diff --git a/dsa.h b/dsa.h
new file mode 100644
index 00000000..65e651d9
--- /dev/null
+++ b/dsa.h
@@ -0,0 +1,20 @@
+#ifndef DSA_H
+#define DSA_H
+
+Key	*dsa_serverkey_from_blob(char *serverhostkey, int serverhostkeylen);
+Key	*dsa_get_serverkey(char *filename);
+int	dsa_make_serverkey_blob(Key *key, unsigned char **blobp, unsigned int *lenp);
+
+int
+dsa_sign(
+    Key *key,
+    unsigned char **sigp, int *lenp,
+    unsigned char *hash, int hlen);
+
+int
+dsa_verify(
+    Key *key,
+    unsigned char *signature, int signaturelen,
+    unsigned char *hash, int hlen);
+
+#endif
diff --git a/hmac.c b/hmac.c
new file mode 100644
index 00000000..45037ef8
--- /dev/null
+++ b/hmac.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2000 Markus Friedl.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by Markus Friedl.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+RCSID("$Id: hmac.c,v 1.1 2000/04/03 20:06:15 markus Exp $");
+
+#include "xmalloc.h"
+#include "ssh.h"
+#include "getput.h"
+
+#if HAVE_OPENSSL
+# include <openssl/hmac.h>
+#endif /* HAVE_OPENSSL */
+#if HAVE_SSL
+# include <ssl/hmac.h>
+#endif /* HAVE_SSL */
+
+unsigned char *
+hmac(
+    EVP_MD *evp_md,
+    unsigned int seqno,
+    unsigned char *data, int datalen,
+    unsigned char *key, int keylen)
+{
+	HMAC_CTX c;
+	static unsigned char m[EVP_MAX_MD_SIZE];
+	unsigned char b[4];
+
+	if (key == NULL)
+		fatal("hmac: no key");
+	HMAC_Init(&c, key, keylen, evp_md);
+	PUT_32BIT(b, seqno);
+	HMAC_Update(&c, b, sizeof b);
+	HMAC_Update(&c, data, datalen);
+	HMAC_Final(&c, m, NULL);
+	HMAC_cleanup(&c);
+	return(m);
+}
diff --git a/hmac.h b/hmac.h
new file mode 100644
index 00000000..fb680292
--- /dev/null
+++ b/hmac.h
@@ -0,0 +1,11 @@
+#ifndef HMAC_H
+#define HMAC_H
+
+unsigned char *
+hmac(
+    EVP_MD *evp_md,
+    unsigned int seqno,
+    unsigned char *data, int datalen,
+    unsigned char *key, int len);
+
+#endif
diff --git a/kex.c b/kex.c
new file mode 100644
index 00000000..e730536a
--- /dev/null
+++ b/kex.c
@@ -0,0 +1,407 @@
+/*
+ * Copyright (c) 2000 Markus Friedl.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by Markus Friedl.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+RCSID("$Id: kex.c,v 1.1 2000/04/04 04:39:02 damien Exp $");
+
+#include "ssh.h"
+#include "ssh2.h"
+#include "xmalloc.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "cipher.h"
+#include "compat.h"
+
+#if HAVE_OPENSSL
+# include <openssl/bn.h>
+# include <openssl/dh.h>
+# include <openssl/crypto.h>
+# include <openssl/bio.h>
+# include <openssl/bn.h>
+# include <openssl/dh.h>
+# include <openssl/pem.h>
+#endif /* HAVE_OPENSSL */
+#if HAVE_SSL
+# include <ssl/bn.h>
+# include <ssl/dh.h>
+# include <ssl/crypto.h>
+# include <ssl/bio.h>
+# include <ssl/bn.h>
+# include <ssl/dh.h>
+# include <ssl/pem.h>
+#endif /* HAVE_SSL */
+
+#include "entropy.h"
+#include "kex.h"
+
+Buffer *
+kex_init(char *myproposal[PROPOSAL_MAX])
+{
+	char c = 0;
+	unsigned char cookie[16];
+	u_int32_t rand = 0;
+	int i;
+	Buffer *ki = xmalloc(sizeof(*ki));
+	for (i = 0; i < 16; i++) {
+		if (i % 4 == 0)
+			rand = arc4random();
+		cookie[i] = rand & 0xff;
+		rand >>= 8;
+	}
+	buffer_init(ki);
+	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) */
+	return ki;
+}
+
+/* diffie-hellman-group1-sha1 */
+
+DH *
+new_dh_group1()
+{
+	static char *group1 =
+	    "FFFFFFFF" "FFFFFFFF" "C90FDAA2" "2168C234" "C4C6628B" "80DC1CD1"
+	    "29024E08" "8A67CC74" "020BBEA6" "3B139B22" "514A0879" "8E3404DD"
+	    "EF9519B3" "CD3A431B" "302B0A6D" "F25F1437" "4FE1356D" "6D51C245"
+	    "E485B576" "625E7EC6" "F44C42E9" "A637ED6B" "0BFF5CB6" "F406B7ED"
+	    "EE386BFB" "5A899FA5" "AE9F2411" "7C4B1FE6" "49286651" "ECE65381"
+	    "FFFFFFFF" "FFFFFFFF";
+	DH *dh;
+	int ret;
+	dh = DH_new();
+	if(dh == NULL)
+		fatal("DH_new");
+	ret = BN_hex2bn(&dh->p,group1);
+	if(ret<0)
+		fatal("BN_hex2bn");
+	dh->g = BN_new();
+	if(dh->g == NULL)
+		fatal("DH_new g");
+	BN_set_word(dh->g,2);
+
+	seed_rng();
+	if (DH_generate_key(dh) == 0)
+		fatal("DH_generate_key");
+	seed_rng();
+
+	return dh;
+}
+
+void
+bignum_print(BIGNUM *b)
+{
+	BN_print_fp(stderr,b);
+}
+
+void
+dump_digest(unsigned char *digest, int len)
+{
+	int i;
+        for (i = 0; i< len; i++){
+                fprintf(stderr, "%02x", digest[i]);
+		if(i%2!=0)
+			fprintf(stderr, " ");
+	}
+        fprintf(stderr, "\n");
+}
+
+unsigned char *
+kex_hash(
+    char *client_version_string,
+    char *server_version_string,
+    char *ckexinit, int ckexinitlen,
+    char *skexinit, int skexinitlen,
+    char *serverhostkeyblob, int sbloblen,
+    BIGNUM *client_dh_pub,
+    BIGNUM *server_dh_pub,
+    BIGNUM *shared_secret)
+{
+	Buffer b;
+	static unsigned char digest[EVP_MAX_MD_SIZE];
+	EVP_MD *evp_md = EVP_sha1();
+	EVP_MD_CTX md;
+
+	buffer_init(&b);
+	buffer_put_string(&b, client_version_string, strlen(client_version_string));
+	buffer_put_string(&b, server_version_string, strlen(server_version_string));
+
+	/* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
+	buffer_put_int(&b, ckexinitlen+1);
+	buffer_put_char(&b, SSH2_MSG_KEXINIT);
+	buffer_append(&b, ckexinit, ckexinitlen);
+	buffer_put_int(&b, skexinitlen+1);
+	buffer_put_char(&b, SSH2_MSG_KEXINIT);
+	buffer_append(&b, skexinit, skexinitlen);
+
+	buffer_put_string(&b, serverhostkeyblob, sbloblen);
+	buffer_put_bignum2(&b, client_dh_pub);
+	buffer_put_bignum2(&b, server_dh_pub);
+	buffer_put_bignum2(&b, shared_secret);
+	
+#ifdef DEBUG_KEX
+	buffer_dump(&b);
+#endif
+
+	EVP_DigestInit(&md, evp_md);
+	EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
+	EVP_DigestFinal(&md, digest, NULL);
+
+	buffer_free(&b);
+
+#ifdef DEBUG_KEX
+        dump_digest(digest, evp_md->md_size);
+#endif
+	return digest;
+}
+
+unsigned char *
+derive_key(int id, int need, char unsigned *hash, BIGNUM *shared_secret)
+{
+	Buffer b;
+	EVP_MD *evp_md = EVP_sha1();
+	EVP_MD_CTX md;
+	char c = id;
+	int have;
+	int mdsz = evp_md->md_size;
+	unsigned char *digest = xmalloc(((need+mdsz-1)/mdsz)*mdsz);
+
+	buffer_init(&b);
+	buffer_put_bignum2(&b, shared_secret);
+
+	EVP_DigestInit(&md, evp_md);
+	EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));	/* shared_secret K */
+	EVP_DigestUpdate(&md, hash, mdsz);		/* transport-06 */
+	EVP_DigestUpdate(&md, &c, 1);			/* key id */
+	EVP_DigestUpdate(&md, hash, mdsz);		/* session id */
+	EVP_DigestFinal(&md, digest, NULL);
+
+	/* expand */
+	for (have = mdsz; need > have; have += mdsz) {
+		EVP_DigestInit(&md, evp_md);
+		EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
+		EVP_DigestUpdate(&md, hash, mdsz);
+		EVP_DigestUpdate(&md, digest, have);
+		EVP_DigestFinal(&md, digest + have, NULL);
+	}
+	buffer_free(&b);
+#ifdef DEBUG_KEX
+	fprintf(stderr, "Digest '%c'== ", c);
+	dump_digest(digest, need);
+#endif
+	return digest;
+}
+
+#define NKEYS	6
+
+#define	MAX_PROP	20
+#define	SEP	","
+
+char *
+get_match(char *client, char *server)
+{
+	char *sproposals[MAX_PROP];
+	char *p;
+	int i, j, nproposals;
+
+	for ((p = strtok(server, SEP)), i=0; p; (p = strtok(NULL, SEP)), i++) {
+		if (i < MAX_PROP)
+			sproposals[i] = p;
+		else
+			break;
+	}
+	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);
+	}
+	return NULL;
+}
+void
+choose_enc(Enc *enc, char *client, char *server)
+{
+	char *name = get_match(client, server);
+	if (name == NULL)
+		fatal("no matching cipher found: client %s server %s", client, server);
+	enc->type = cipher_number(name);
+
+	switch (enc->type) {
+	case SSH_CIPHER_3DES_CBC:
+		enc->key_len = 24;
+		enc->iv_len = 8;
+		enc->block_size = 8;
+		break;
+	case SSH_CIPHER_BLOWFISH_CBC:
+	case SSH_CIPHER_CAST128_CBC:
+		enc->key_len = 16;
+		enc->iv_len = 8;
+		enc->block_size = 8;
+		break;
+	case SSH_CIPHER_ARCFOUR:
+		enc->key_len = 16;
+		enc->iv_len = 0;
+		enc->block_size = 8;
+		break;
+	default:
+		fatal("unsupported cipher %s", name);
+	}
+	enc->name = name;
+	enc->enabled = 0;
+	enc->iv = NULL;
+	enc->key = NULL;
+}
+void
+choose_mac(Mac *mac, char *client, char *server)
+{
+	char *name = get_match(client, server);
+	if (name == NULL)
+		fatal("no matching mac found: client %s server %s", client, server);
+	if (strcmp(name, "hmac-md5") == 0) {
+		mac->md = EVP_md5();
+	} else if (strcmp(name, "hmac-sha1") == 0) {
+		mac->md = EVP_sha1();
+	} else if (strcmp(name, "hmac-ripemd160@openssh.com") == 0) {
+		mac->md = EVP_ripemd160();
+	} else {
+		fatal("unsupported mac %s", name);
+	}
+	mac->name = name;
+	mac->mac_len = mac->md->md_size;
+	mac->key_len = datafellows ? 16 : mac->mac_len;
+	mac->key = NULL;
+	mac->enabled = 0;
+}
+void
+choose_comp(Comp *comp, char *client, char *server)
+{
+	char *name = get_match(client, server);
+	if (name == NULL)
+		fatal("no matching comp found: client %s server %s", client, server);
+	if (strcmp(name, "zlib") == 0) {
+		comp->type = 1;
+	} else if (strcmp(name, "none") == 0) {
+		comp->type = 0;
+	} else {
+		fatal("unsupported comp %s", name);
+	}
+	comp->name = name;
+}
+void
+choose_kex(Kex *k, char *client, char *server)
+{
+	k->name = get_match(client, server);
+	if (k->name == NULL)
+		fatal("no kex alg");
+    	if (strcmp(k->name, KEX_DH1) != 0)
+		fatal("bad kex alg %s", k->name);
+}
+void
+choose_hostkeyalg(Kex *k, char *client, char *server)
+{
+	k->hostkeyalg = get_match(client, server);
+	if (k->hostkeyalg == NULL)
+		fatal("no hostkey alg");
+	if (strcmp(k->hostkeyalg, KEX_DSS) != 0)
+		fatal("bad hostkey alg %s", k->hostkeyalg);
+}
+
+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;
+	Kex *k;
+
+	k = xmalloc(sizeof(*k));
+	memset(k, 0, sizeof(*k));
+	k->server = server;
+
+	for (mode = 0; mode < MODE_MAX; mode++) {
+		int nenc, nmac, ncomp;
+		ctos = (!k->server && mode == MODE_OUT) || (k->server && mode == MODE_IN);
+		nenc  = ctos ? PROPOSAL_ENC_ALGS_CTOS  : PROPOSAL_ENC_ALGS_STOC;
+		nmac  = ctos ? PROPOSAL_MAC_ALGS_CTOS  : PROPOSAL_MAC_ALGS_STOC;
+		ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
+		choose_enc (&k->enc [mode], cprop[nenc],  sprop[nenc]);
+		choose_mac (&k->mac [mode], cprop[nmac],  sprop[nmac]);
+		choose_comp(&k->comp[mode], cprop[ncomp], sprop[ncomp]);
+		log("kex: %s %s %s %s",
+		    ctos ? "client->server" : "server->client",
+		    k->enc[mode].name,
+		    k->mac[mode].name,
+		    k->comp[mode].name);
+	}
+	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)
+		    need = k->enc[mode].key_len;
+	    if (need < k->enc[mode].iv_len)
+		    need = k->enc[mode].iv_len;
+	    if (need < k->mac[mode].key_len)
+		    need = k->mac[mode].key_len;
+	}
+	/* need runden? */
+#define WE_NEED 32
+	k->we_need = WE_NEED;
+	k->we_need = need;
+	return k;
+}
+
+int
+kex_derive_keys(Kex *k, unsigned char *hash, BIGNUM *shared_secret)
+{
+	int i;
+	int mode;
+	int ctos;
+	unsigned char *keys[NKEYS];
+
+	for (i = 0; i < NKEYS; i++)
+		keys[i] = derive_key('A'+i, k->we_need, hash, shared_secret);
+
+	for (mode = 0; mode < MODE_MAX; mode++) {
+		ctos = (!k->server && mode == MODE_OUT) || (k->server && mode == MODE_IN);
+		k->enc[mode].iv  = keys[ctos ? 0 : 1];
+		k->enc[mode].key = keys[ctos ? 2 : 3];
+		k->mac[mode].key = keys[ctos ? 4 : 5];
+	}
+	return 0;
+}
diff --git a/kex.h b/kex.h
new file mode 100644
index 00000000..f9e79994
--- /dev/null
+++ b/kex.h
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2000 Markus Friedl.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by Markus Friedl.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef KEX_H
+#define KEX_H
+
+#define	KEX_DH1	"diffie-hellman-group1-sha1"
+#define KEX_DSS	"ssh-dss"
+
+enum kex_init_proposals {
+	PROPOSAL_KEX_ALGS,
+	PROPOSAL_SERVER_HOST_KEY_ALGS,
+	PROPOSAL_ENC_ALGS_CTOS,
+	PROPOSAL_ENC_ALGS_STOC,
+	PROPOSAL_MAC_ALGS_CTOS,
+	PROPOSAL_MAC_ALGS_STOC,
+	PROPOSAL_COMP_ALGS_CTOS,
+	PROPOSAL_COMP_ALGS_STOC,
+	PROPOSAL_LANG_CTOS,
+	PROPOSAL_LANG_STOC,
+	PROPOSAL_MAX
+};
+
+enum kex_modes {
+	MODE_IN,
+	MODE_OUT,
+	MODE_MAX
+};
+
+typedef struct Kex Kex;
+typedef struct Mac Mac;
+typedef struct Comp Comp;
+typedef struct Enc Enc;
+
+struct Enc {
+	int		type;
+	int		enabled;
+	int		block_size;
+	unsigned char	*key;
+	unsigned char	*iv;
+	int		key_len;
+	int		iv_len;
+	char		*name;
+};
+struct Mac {
+	EVP_MD		*md;
+	int		enabled;
+	int		mac_len;
+	unsigned char	*key;
+	int		key_len;
+	char		*name;
+};
+struct Comp {
+	int		type;
+	int		enabled;
+	char		*name;
+};
+struct Kex {
+	Enc		enc [MODE_MAX];
+	Mac		mac [MODE_MAX];
+	Comp		comp[MODE_MAX];
+	int		we_need;
+	int		server;
+	char		*name;
+	char		*hostkeyalg;
+};
+
+Buffer	*kex_init(char *myproposal[PROPOSAL_MAX]);
+DH	*new_dh_group1();
+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);
+
+unsigned char *
+kex_hash(
+    char *client_version_string,
+    char *server_version_string,
+    char *ckexinit, int ckexinitlen,
+    char *skexinit, int skexinitlen,
+    char *serverhostkeyblob, int sbloblen,
+    BIGNUM *client_dh_pub,
+    BIGNUM *server_dh_pub,
+    BIGNUM *shared_secret);
+
+#endif
diff --git a/nchan.c b/nchan.c
index 996623fb..3795d8ad 100644
--- a/nchan.c
+++ b/nchan.c
@@ -28,7 +28,7 @@
  */
 
 #include "includes.h"
-RCSID("$Id: nchan.c,v 1.6 2000/04/01 01:09:24 damien Exp $");
+RCSID("$Id: nchan.c,v 1.7 2000/04/04 04:39:02 damien Exp $");
 
 #include "ssh.h"
 
@@ -37,138 +37,169 @@ RCSID("$Id: nchan.c,v 1.6 2000/04/01 01:09:24 damien Exp $");
 #include "channels.h"
 #include "nchan.h"
 
-static void chan_send_ieof(Channel *c);
-static void chan_send_oclose(Channel *c);
-static void chan_shutdown_write(Channel *c);
-static void chan_shutdown_read(Channel *c);
+#include "ssh2.h"
+#include "compat.h"
 
+/* functions manipulating channel states */
 /*
  * EVENTS update channel input/output states execute ACTIONS
  */
-
 /* events concerning the INPUT from socket for channel (istate) */
-void
-chan_rcvd_oclose(Channel *c)
+chan_event_fn *chan_rcvd_oclose			= NULL;
+chan_event_fn *chan_read_failed			= NULL;
+chan_event_fn *chan_ibuf_empty			= NULL;
+/* events concerning the OUTPUT from channel for socket (ostate) */
+chan_event_fn *chan_rcvd_ieof			= NULL;
+chan_event_fn *chan_write_failed		= NULL;
+chan_event_fn *chan_obuf_empty			= NULL;
+/*
+ * ACTIONS: should never update the channel states
+ */
+static void	chan_send_ieof1(Channel *c);
+static void	chan_send_oclose1(Channel *c);
+static void	chan_send_close2(Channel *c);
+static void	chan_send_eof2(Channel *c);
+
+/* channel cleanup */
+chan_event_fn *chan_delete_if_full_closed	= NULL;
+
+/* helper */
+static void	chan_shutdown_write(Channel *c);
+static void	chan_shutdown_read(Channel *c);
+
+/*
+ * SSH1 specific implementation of event functions
+ */
+
+static void
+chan_rcvd_oclose1(Channel *c)
 {
+	debug("channel %d: rcvd oclose", c->self);
 	switch (c->istate) {
 	case CHAN_INPUT_WAIT_OCLOSE:
-		debug("channel %d: INPUT_WAIT_OCLOSE -> INPUT_CLOSED [rcvd OCLOSE]", c->self);
+		debug("channel %d: input wait_oclose -> closed", c->self);
 		c->istate = CHAN_INPUT_CLOSED;
 		break;
 	case CHAN_INPUT_OPEN:
-		debug("channel %d: INPUT_OPEN -> INPUT_CLOSED [rvcd OCLOSE, send IEOF]", c->self);
+		debug("channel %d: input open -> closed", c->self);
 		chan_shutdown_read(c);
-		chan_send_ieof(c);
+		chan_send_ieof1(c);
 		c->istate = CHAN_INPUT_CLOSED;
 		break;
 	case CHAN_INPUT_WAIT_DRAIN:
 		/* both local read_failed and remote write_failed  */
-		log("channel %d: INPUT_WAIT_DRAIN -> INPUT_CLOSED [rvcd OCLOSE, send IEOF]", c->self);
-		debug("channel %d: INPUT_WAIT_DRAIN -> INPUT_CLOSED [rvcd OCLOSE, send IEOF]", c->self);
-		chan_send_ieof(c);
+		log("channel %d: input drain -> closed", c->self);
+		chan_send_ieof1(c);
 		c->istate = CHAN_INPUT_CLOSED;
 		break;
 	default:
-		error("protocol error: chan_rcvd_oclose %d for istate %d", c->self, c->istate);
+		error("channel %d: protocol error: chan_rcvd_oclose for istate %d",
+		    c->self, c->istate);
 		return;
 	}
 }
-void
-chan_read_failed(Channel *c)
+static void
+chan_read_failed_12(Channel *c)
 {
+	debug("channel %d: read failed", c->self);
 	switch (c->istate) {
 	case CHAN_INPUT_OPEN:
-		debug("channel %d: INPUT_OPEN -> INPUT_WAIT_DRAIN [read failed]", c->self);
+		debug("channel %d: input open -> drain", c->self);
 		chan_shutdown_read(c);
 		c->istate = CHAN_INPUT_WAIT_DRAIN;
 		break;
 	default:
-		error("internal error: we do not read, but chan_read_failed %d for istate %d",
-		      c->self, c->istate);
+		error("channel %d: internal error: we do not read, but chan_read_failed for istate %d",
+		    c->self, c->istate);
 		break;
 	}
 }
-void
-chan_ibuf_empty(Channel *c)
+static void
+chan_ibuf_empty1(Channel *c)
 {
+	debug("channel %d: ibuf empty", c->self);
 	if (buffer_len(&c->input)) {
-		error("internal error: chan_ibuf_empty %d for non empty buffer", c->self);
+		error("channel %d: internal error: chan_ibuf_empty for non empty buffer",
+		    c->self);
 		return;
 	}
 	switch (c->istate) {
 	case CHAN_INPUT_WAIT_DRAIN:
-		debug("channel %d: INPUT_WAIT_DRAIN -> INPUT_WAIT_OCLOSE [inbuf empty, send IEOF]", c->self);
-		chan_send_ieof(c);
+		debug("channel %d: input drain -> wait_oclose", c->self);
+		chan_send_ieof1(c);
 		c->istate = CHAN_INPUT_WAIT_OCLOSE;
 		break;
 	default:
-		error("internal error: chan_ibuf_empty %d for istate %d", c->self, c->istate);
+		error("channel %d: internal error: chan_ibuf_empty for istate %d",
+		    c->self, c->istate);
 		break;
 	}
 }
-
-/* events concerning the OUTPUT from channel for socket (ostate) */
-void
-chan_rcvd_ieof(Channel *c)
+static void
+chan_rcvd_ieof1(Channel *c)
 {
+	debug("channel %d: rcvd ieof", c->self);
 	switch (c->ostate) {
 	case CHAN_OUTPUT_OPEN:
-		debug("channel %d: OUTPUT_OPEN -> OUTPUT_WAIT_DRAIN [rvcd IEOF]", c->self);
+		debug("channel %d: output open -> drain", c->self);
 		c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
 		break;
 	case CHAN_OUTPUT_WAIT_IEOF:
-		debug("channel %d: OUTPUT_WAIT_IEOF -> OUTPUT_CLOSED [rvcd IEOF]", c->self);
+		debug("channel %d: output wait_ieof -> closed", c->self);
 		c->ostate = CHAN_OUTPUT_CLOSED;
 		break;
 	default:
-		error("protocol error: chan_rcvd_ieof %d for ostate %d", c->self, c->ostate);
+		error("channel %d: protocol error: chan_rcvd_ieof for ostate %d",
+		    c->self, c->ostate);
 		break;
 	}
 }
-void
-chan_write_failed(Channel *c)
+static void
+chan_write_failed1(Channel *c)
 {
+	debug("channel %d: write failed", c->self);
 	switch (c->ostate) {
 	case CHAN_OUTPUT_OPEN:
-		debug("channel %d: OUTPUT_OPEN -> OUTPUT_WAIT_IEOF [write failed]", c->self);
-		chan_send_oclose(c);
+		debug("channel %d: output open -> wait_ieof", c->self);
+		chan_send_oclose1(c);
 		c->ostate = CHAN_OUTPUT_WAIT_IEOF;
 		break;
 	case CHAN_OUTPUT_WAIT_DRAIN:
-		debug("channel %d: OUTPUT_WAIT_DRAIN -> OUTPUT_CLOSED [write failed]", c->self);
-		chan_send_oclose(c);
+		debug("channel %d: output wait_drain -> closed", c->self);
+		chan_send_oclose1(c);
 		c->ostate = CHAN_OUTPUT_CLOSED;
 		break;
 	default:
-		error("internal error: chan_write_failed %d for ostate %d", c->self, c->ostate);
+		error("channel %d: internal error: chan_write_failed for ostate %d",
+		    c->self, c->ostate);
 		break;
 	}
 }
-void
-chan_obuf_empty(Channel *c)
+static void
+chan_obuf_empty1(Channel *c)
 {
+	debug("channel %d: obuf empty", c->self);
 	if (buffer_len(&c->output)) {
-		debug("internal error: chan_obuf_empty %d for non empty buffer", c->self);
+		error("channel %d: internal error: chan_obuf_empty for non empty buffer",
+		    c->self);
 		return;
 	}
 	switch (c->ostate) {
 	case CHAN_OUTPUT_WAIT_DRAIN:
-		debug("channel %d: OUTPUT_WAIT_DRAIN -> OUTPUT_CLOSED [obuf empty, send OCLOSE]", c->self);
-		chan_send_oclose(c);
+		debug("channel %d: output drain -> closed", c->self);
+		chan_send_oclose1(c);
 		c->ostate = CHAN_OUTPUT_CLOSED;
 		break;
 	default:
-		error("internal error: chan_obuf_empty %d for ostate %d", c->self, c->ostate);
+		error("channel %d: internal error: chan_obuf_empty for ostate %d",
+		    c->self, c->ostate);
 		break;
 	}
 }
-
-/*
- * ACTIONS: should never update the channel states: c->istate or c->ostate
- */
 static void
-chan_send_ieof(Channel *c)
+chan_send_ieof1(Channel *c)
 {
+	debug("channel %d: send ieof", c->self);
 	switch (c->istate) {
 	case CHAN_INPUT_OPEN:
 	case CHAN_INPUT_WAIT_DRAIN:
@@ -177,13 +208,15 @@ chan_send_ieof(Channel *c)
 		packet_send();
 		break;
 	default:
-		error("internal error: channel %d: cannot send IEOF for istate %d", c->self, c->istate);
+		error("channel %d: internal error: cannot send ieof for istate %d",
+		    c->self, c->istate);
 		break;
 	}
 }
 static void
-chan_send_oclose(Channel *c)
+chan_send_oclose1(Channel *c)
 {
+	debug("channel %d: send oclose", c->self);
 	switch (c->ostate) {
 	case CHAN_OUTPUT_OPEN:
 	case CHAN_OUTPUT_WAIT_DRAIN:
@@ -194,40 +227,246 @@ chan_send_oclose(Channel *c)
 		packet_send();
 		break;
 	default:
-		error("internal error: channel %d: cannot send OCLOSE for ostate %d", c->self, c->istate);
+		error("channel %d: internal error: cannot send oclose for ostate %d",
+		     c->self, c->ostate);
 		break;
 	}
 }
+static void
+chan_delete_if_full_closed1(Channel *c)
+{
+	if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) {
+		debug("channel %d: full closed", c->self);
+		channel_free(c->self);
+	}
+}
 
-/* helper */
+/*
+ * the same for SSH2
+ */
 static void
-chan_shutdown_write(Channel *c)
+chan_rcvd_oclose2(Channel *c)
 {
-	/* shutdown failure is allowed if write failed already */
-	debug("channel %d: shutdown_write", c->self);
-	if (shutdown(c->sock, SHUT_WR) < 0)
-		debug("chan_shutdown_write failed for #%d/fd%d: %.100s",
-		      c->self, c->sock, strerror(errno));
+	debug("channel %d: rcvd close", c->self);
+	if (c->flags & CHAN_CLOSE_RCVD)
+		error("channel %d: protocol error: close rcvd twice", c->self);
+	c->flags |= CHAN_CLOSE_RCVD;
+	if (c->type == SSH_CHANNEL_LARVAL) {
+		/* tear down larval channels immediately */
+		c->ostate = CHAN_OUTPUT_CLOSED;
+		c->istate = CHAN_INPUT_CLOSED;
+		return;
+	}
+	switch (c->ostate) {
+	case CHAN_OUTPUT_OPEN:
+		/* wait until a data from the channel is consumed if a CLOSE is received */
+		debug("channel %d: output open -> drain", c->self);
+		c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
+		break;
+	}
+	switch (c->istate) {
+	case CHAN_INPUT_OPEN:
+		debug("channel %d: input open -> closed", c->self);
+		chan_shutdown_read(c);
+		break;
+	case CHAN_INPUT_WAIT_DRAIN:
+		debug("channel %d: input drain -> closed", c->self);
+		chan_send_eof2(c);
+		break;
+	}
+	c->istate = CHAN_INPUT_CLOSED;
 }
 static void
-chan_shutdown_read(Channel *c)
+chan_ibuf_empty2(Channel *c)
+{
+	debug("channel %d: ibuf empty", c->self);
+	if (buffer_len(&c->input)) {
+		error("channel %d: internal error: chan_ibuf_empty for non empty buffer",
+		     c->self);
+		return;
+	}
+	switch (c->istate) {
+	case CHAN_INPUT_WAIT_DRAIN:
+		debug("channel %d: input drain -> closed", c->self);
+		if (!(c->flags & CHAN_CLOSE_SENT))
+			chan_send_eof2(c);
+		c->istate = CHAN_INPUT_CLOSED;
+		break;
+	default:
+		error("channel %d: internal error: chan_ibuf_empty for istate %d",
+		     c->self, c->istate);
+		break;
+	}
+}
+static void
+chan_rcvd_ieof2(Channel *c)
 {
-	debug("channel %d: shutdown_read", c->self);
-	if (shutdown(c->sock, SHUT_RD) < 0)
-		error("chan_shutdown_read failed for #%d/fd%d [i%d o%d]: %.100s",
-		      c->self, c->sock, c->istate, c->ostate, strerror(errno));
+	debug("channel %d: rcvd eof", c->self);
+	if (c->ostate == CHAN_OUTPUT_OPEN) {
+		debug("channel %d: output open -> drain", c->self);
+		c->ostate = CHAN_OUTPUT_WAIT_DRAIN;
+	}
 }
-void
-chan_delete_if_full_closed(Channel *c)
+static void
+chan_write_failed2(Channel *c)
+{
+	debug("channel %d: write failed", c->self);
+	switch (c->ostate) {
+	case CHAN_OUTPUT_OPEN:
+		debug("channel %d: output open -> closed", c->self);
+		chan_shutdown_write(c); // ??
+		c->ostate = CHAN_OUTPUT_CLOSED;
+		break;
+	case CHAN_OUTPUT_WAIT_DRAIN:
+		debug("channel %d: output drain -> closed", c->self);
+		chan_shutdown_write(c);
+		c->ostate = CHAN_OUTPUT_CLOSED;
+		break;
+	default:
+		error("channel %d: internal error: chan_write_failed for ostate %d",
+		    c->self, c->ostate);
+		break;
+	}
+}
+static void
+chan_obuf_empty2(Channel *c)
+{
+	debug("channel %d: obuf empty", c->self);
+	if (buffer_len(&c->output)) {
+		error("internal error: chan_obuf_empty %d for non empty buffer",
+		    c->self);
+		return;
+	}
+	switch (c->ostate) {
+	case CHAN_OUTPUT_WAIT_DRAIN:
+		debug("channel %d: output drain -> closed", c->self);
+		chan_shutdown_write(c);
+		c->ostate = CHAN_OUTPUT_CLOSED;
+		break;
+	default:
+		error("channel %d: internal error: chan_obuf_empty for ostate %d",
+		    c->self, c->ostate);
+		break;
+	}
+}
+static void
+chan_send_eof2(Channel *c)
+{
+	debug("channel %d: send eof", c->self);
+	switch (c->istate) {
+	case CHAN_INPUT_WAIT_DRAIN:
+		packet_start(SSH2_MSG_CHANNEL_EOF);
+		packet_put_int(c->remote_id);
+		packet_send();
+		break;
+	default:
+		error("channel %d: internal error: cannot send eof for istate %d",
+		    c->self, c->istate);
+		break;
+	}
+}
+static void
+chan_send_close2(Channel *c)
+{
+	debug("channel %d: send close", c->self);
+	if (c->ostate != CHAN_OUTPUT_CLOSED ||
+	    c->istate != CHAN_INPUT_CLOSED) {
+		error("channel %d: internal error: cannot send close for istate/ostate %d/%d",
+		    c->self, c->istate, c->ostate);
+	} else if (c->flags & CHAN_CLOSE_SENT) {
+		error("channel %d: internal error: already sent close", c->self);
+	} else {
+		packet_start(SSH2_MSG_CHANNEL_CLOSE);
+		packet_put_int(c->remote_id);
+		packet_send();
+		c->flags |= CHAN_CLOSE_SENT;
+	}
+}
+static void
+chan_delete_if_full_closed2(Channel *c)
 {
 	if (c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED) {
-		debug("channel %d: full closed", c->self);
-		channel_free(c->self);
+		if (!(c->flags & CHAN_CLOSE_SENT)) {
+			chan_send_close2(c);
+		}
+		if ((c->flags & CHAN_CLOSE_SENT) && 
+		    (c->flags & CHAN_CLOSE_RCVD)) {
+			debug("channel %d: full closed2", c->self);
+			channel_free(c->self);
+		} 
 	}
 }
+
+/* shared */
 void
 chan_init_iostates(Channel *c)
 {
 	c->ostate = CHAN_OUTPUT_OPEN;
 	c->istate = CHAN_INPUT_OPEN;
+	c->flags = 0;
+}
+
+/* init */
+void
+chan_init(void)
+{
+	if (compat20) {
+		chan_rcvd_oclose		= chan_rcvd_oclose2;
+		chan_read_failed		= chan_read_failed_12;
+		chan_ibuf_empty			= chan_ibuf_empty2;
+
+		chan_rcvd_ieof			= chan_rcvd_ieof2;
+		chan_write_failed		= chan_write_failed2;
+		chan_obuf_empty			= chan_obuf_empty2;
+
+		chan_delete_if_full_closed	= chan_delete_if_full_closed2;
+	} else {
+		chan_rcvd_oclose		= chan_rcvd_oclose1;
+		chan_read_failed		= chan_read_failed_12;
+		chan_ibuf_empty			= chan_ibuf_empty1;
+
+		chan_rcvd_ieof			= chan_rcvd_ieof1;
+		chan_write_failed		= chan_write_failed1;
+		chan_obuf_empty			= chan_obuf_empty1;
+
+		chan_delete_if_full_closed	= chan_delete_if_full_closed1;
+	}
+}
+
+/* helper */
+static void
+chan_shutdown_write(Channel *c)
+{
+	buffer_consume(&c->output, buffer_len(&c->output));
+	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
+		return;
+	/* shutdown failure is allowed if write failed already */
+	debug("channel %d: close_write", c->self);
+	if (c->sock != -1) {
+		if (shutdown(c->sock, SHUT_WR) < 0)
+			debug("channel %d: chan_shutdown_write: shutdown() failed for fd%d: %.100s",
+			    c->self, c->sock, strerror(errno));
+	} else {
+		if (close(c->wfd) < 0)
+			log("channel %d: chan_shutdown_write: close() failed for fd%d: %.100s",
+			    c->self, c->wfd, strerror(errno));
+		c->wfd = -1;
+	}
+}
+static void
+chan_shutdown_read(Channel *c)
+{
+	if (compat20 && c->type == SSH_CHANNEL_LARVAL)
+		return;
+	debug("channel %d: close_read", c->self);
+	if (c->sock != -1) {
+		if (shutdown(c->sock, SHUT_RD) < 0)
+			error("channel %d: chan_shutdown_read: shutdown() failed for fd%d [i%d o%d]: %.100s",
+			    c->self, c->sock, c->istate, c->ostate, strerror(errno));
+	} else {
+		if (close(c->rfd) < 0)
+			log("channel %d: chan_shutdown_read: close() failed for fd%d: %.100s",
+			    c->self, c->rfd, strerror(errno));
+		c->rfd = -1;
+	}
 }
diff --git a/nchan.h b/nchan.h
index 0ceee1c7..ae2b7061 100644
--- a/nchan.h
+++ b/nchan.h
@@ -27,7 +27,7 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-/* RCSID("$Id: nchan.h,v 1.4 2000/04/01 01:09:24 damien Exp $"); */
+/* RCSID("$Id: nchan.h,v 1.5 2000/04/04 04:39:02 damien Exp $"); */
 
 #ifndef NCHAN_H
 #define NCHAN_H
@@ -72,17 +72,25 @@
 #define CHAN_OUTPUT_WAIT_IEOF		0x40
 #define CHAN_OUTPUT_CLOSED		0x80
 
-/* EVENTS for the input state */
-void    chan_rcvd_oclose(Channel * c);
-void    chan_read_failed(Channel * c);
-void    chan_ibuf_empty(Channel * c);
+#define CHAN_CLOSE_SENT			0x01
+#define CHAN_CLOSE_RCVD			0x02
 
-/* EVENTS for the output state */
-void    chan_rcvd_ieof(Channel * c);
-void    chan_write_failed(Channel * c);
-void    chan_obuf_empty(Channel * c);
 
-void    chan_init_iostates(Channel * c);
+/* Channel EVENTS */
+typedef void    chan_event_fn(Channel * c);
+
+/* for the input state */
+extern chan_event_fn	*chan_rcvd_oclose;
+extern chan_event_fn	*chan_read_failed;
+extern chan_event_fn	*chan_ibuf_empty;
+
+/* for the output state */
+extern chan_event_fn	*chan_rcvd_ieof;
+extern chan_event_fn	*chan_write_failed;
+extern chan_event_fn	*chan_obuf_empty;
 
-void	chan_delete_if_full_closed(Channel *c);
+extern chan_event_fn	*chan_delete_if_full_closed;
+
+void    chan_init_iostates(Channel * c);
+void	chan_init(void);
 #endif
diff --git a/nchan2.ms b/nchan2.ms
new file mode 100644
index 00000000..1b119d13
--- /dev/null
+++ b/nchan2.ms
@@ -0,0 +1,64 @@
+.TL
+OpenSSH Channel Close Protocol 2.0 Implementation
+.SH
+Channel Input State Diagram
+.PS
+reset
+l=1
+s=1.2
+ellipsewid=s*ellipsewid
+boxwid=s*boxwid
+ellipseht=s*ellipseht
+S1: ellipse "INPUT" "OPEN"
+move right 2*l from last ellipse.e
+S3: ellipse invis
+move down l from last ellipse.s
+S4: ellipse "INPUT" "CLOSED"
+move down l from 1st ellipse.s
+S2: ellipse "INPUT" "WAIT" "DRAIN"
+arrow from S1.e to S4.n
+box invis "rcvd CLOSE/" "shutdown_read" with .sw at last arrow.c
+arrow "ibuf_empty ||" "rcvd CLOSE/" "send EOF" "" from S2.e to S4.w
+arrow from S1.s to S2.n
+box invis "read_failed/" "shutdown_read" with .e at last arrow.c
+ellipse wid .9*ellipsewid ht .9*ellipseht at S4
+arrow "start" "" from S1.w+(-0.5,0) to S1.w
+.PE
+.SH
+Channel Output State Diagram
+.PS
+S1: ellipse "OUTPUT" "OPEN"
+move right 2*l from last ellipse.e
+S3: ellipse invis
+move down l from last ellipse.s
+S4: ellipse "OUTPUT" "CLOSED"
+move down l from 1st ellipse.s
+S2: ellipse "OUTPUT" "WAIT" "DRAIN"
+arrow from S1.e to S4.n
+box invis "write_failed/" "shutdown_write" with .sw at last arrow.c
+arrow "obuf_empty ||" "write_failed/" "shutdown_write" "" from S2.e to S4.w
+arrow from S1.s to S2.n
+box invis "rcvd EOF ||" "rcvd CLOSE/" "-" with .e at last arrow.c
+ellipse wid .9*ellipsewid ht .9*ellipseht at S4
+arrow "start" "" from S1.w+(-0.5,0) to S1.w
+.PE
+.SH
+Notes
+.PP
+The input buffer is filled with data from the socket
+(the socket represents the local consumer/producer of the
+forwarded channel).
+The data is then sent over the INPUT-end (transmit-end) of the channel to the
+remote peer.
+Data sent by the peer is received on the OUTPUT-end (receive-end),
+saved in the output buffer and written to the socket.
+.PP
+If the local protocol instance has forwarded all data on the
+INPUT-end of the channel, it sends an EOF message to the peer.
+.PP
+A CLOSE message is sent to the peer if
+both the INPUT- and the OUTOUT-half of the local
+end of the channel are closed.
+.PP
+The channel can be deallocated by a protocol instance
+if a CLOSE message he been both sent and received.
diff --git a/packet.c b/packet.c
index ffce2c74..3875d8f9 100644
--- a/packet.c
+++ b/packet.c
@@ -11,11 +11,13 @@
  * 
  * This file contains code implementing the packet protocol and communication
  * with the other side.  This same code is used both on client and server side.
- * 
+ *
+ * SSH2 packet format added by Markus Friedl.
+ *
  */
 
 #include "includes.h"
-RCSID("$Id: packet.c,v 1.13 2000/04/01 01:09:25 damien Exp $");
+RCSID("$Id: packet.c,v 1.14 2000/04/04 04:39:03 damien Exp $");
 
 #include "xmalloc.h"
 #include "buffer.h"
@@ -30,6 +32,22 @@ RCSID("$Id: packet.c,v 1.13 2000/04/01 01:09:25 damien Exp $");
 #include "deattack.h"
 #include "channels.h"
 
+#include "compat.h"
+#include "ssh2.h"
+
+#include <ssl/bn.h>
+#include <ssl/dh.h>
+#include <ssl/hmac.h>
+#include "buffer.h"
+#include "kex.h"
+#include "hmac.h"
+
+#ifdef PACKET_DEBUG
+#define DBG(x) x
+#else
+#define DBG(x)
+#endif
+
 /*
  * This variable contains the file descriptors used for communicating with
  * the other side.  connection_in is used for reading; connection_out for
@@ -81,11 +99,45 @@ static int initialized = 0;
 /* Set to true if the connection is interactive. */
 static int interactive_mode = 0;
 
+/* True if SSH2 packet format is used */
+int use_ssh2_packet_format = 0;
+
+/* Session key information for Encryption and MAC */
+Kex	*kex = NULL;
+
+void
+packet_set_kex(Kex *k)
+{
+	if( k->mac[MODE_IN ].key == NULL ||
+	    k->enc[MODE_IN ].key == NULL ||
+	    k->enc[MODE_IN ].iv  == NULL ||
+	    k->mac[MODE_OUT].key == NULL ||
+	    k->enc[MODE_OUT].key == NULL ||
+	    k->enc[MODE_OUT].iv  == NULL)
+		fatal("bad KEX");
+	kex = k;
+}
+void
+clear_enc_keys(Enc *enc, int len)
+{
+	memset(enc->iv,  0, len);
+	memset(enc->key, 0, len);
+	xfree(enc->iv);
+	xfree(enc->key);
+	enc->iv = NULL;
+	enc->key = NULL;
+}
+void
+packet_set_ssh2_format(void)
+{
+	debug("use_ssh2_packet_format");
+	use_ssh2_packet_format = 1;
+}
+
 /*
  * Sets the descriptors used for communication.  Disables encryption until
  * packet_set_encryption_key is called.
  */
-
 void
 packet_set_connection(int fd_in, int fd_out)
 {
@@ -225,6 +277,7 @@ packet_get_protocol_flags()
  * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
  */
 
+/*** XXXXX todo: kex means re-init */
 void
 packet_start_compression(int level)
 {
@@ -242,7 +295,7 @@ packet_start_compression(int level)
 
 void
 packet_encrypt(CipherContext * cc, void *dest, void *src,
-	       unsigned int bytes)
+    unsigned int bytes)
 {
 	cipher_encrypt(cc, dest, src, bytes);
 }
@@ -254,7 +307,7 @@ packet_encrypt(CipherContext * cc, void *dest, void *src,
 
 void
 packet_decrypt(CipherContext * cc, void *dest, void *src,
-	       unsigned int bytes)
+    unsigned int bytes)
 {
 	int i;
 
@@ -266,15 +319,11 @@ packet_decrypt(CipherContext * cc, void *dest, void *src,
 	 * (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com)
 	 */
 
-	switch (cc->type) {
-	case SSH_CIPHER_NONE:
+	if (cc->type == SSH_CIPHER_NONE || compat20) {
 		i = DEATTACK_OK;
-		break;
-	default:
+	} else {
 		i = detect_attack(src, bytes, NULL);
-		break;
 	}
-
 	if (i == DEATTACK_DETECTED)
 		packet_disconnect("crc32 compensation attack: network attack detected");
 
@@ -289,8 +338,11 @@ packet_decrypt(CipherContext * cc, void *dest, void *src,
 
 void
 packet_set_encryption_key(const unsigned char *key, unsigned int keylen,
-			  int cipher)
+    int cipher)
 {
+	if (keylen < 20)
+		fatal("keylen too small: %d", keylen);
+
 	/* All other ciphers use the same key in both directions for now. */
 	cipher_set_key(&receive_context, cipher, key, keylen, 0);
 	cipher_set_key(&send_context, cipher, key, keylen, 1);
@@ -299,7 +351,7 @@ packet_set_encryption_key(const unsigned char *key, unsigned int keylen,
 /* Starts constructing a packet to send. */
 
 void
-packet_start(int type)
+packet_start1(int type)
 {
 	char buf[9];
 
@@ -309,6 +361,29 @@ packet_start(int type)
 	buffer_append(&outgoing_packet, buf, 9);
 }
 
+void
+packet_start2(int type)
+{
+	char buf[4+1+1];
+
+	buffer_clear(&outgoing_packet);
+	memset(buf, 0, sizeof buf);
+	/* buf[0..3] = payload_len; */
+	/* buf[4] =    pad_len; */
+	buf[5] = type & 0xff;
+	buffer_append(&outgoing_packet, buf, sizeof buf);
+}
+
+void
+packet_start(int type)
+{
+	DBG(debug("packet_start[%d]",type));
+	if (use_ssh2_packet_format)
+		packet_start2(type);
+	else
+		packet_start1(type);
+}
+
 /* Appends a character to the packet data. */
 
 void
@@ -333,6 +408,18 @@ packet_put_string(const char *buf, unsigned int len)
 {
 	buffer_put_string(&outgoing_packet, buf, len);
 }
+void
+packet_put_cstring(const char *str)
+{
+	buffer_put_string(&outgoing_packet, str, strlen(str));
+}
+
+void
+packet_put_raw(const char *buf, unsigned int len)
+{
+	buffer_append(&outgoing_packet, buf, len);
+}
+
 
 /* Appends an arbitrary precision integer to packet data. */
 
@@ -341,6 +428,11 @@ packet_put_bignum(BIGNUM * value)
 {
 	buffer_put_bignum(&outgoing_packet, value);
 }
+void
+packet_put_bignum2(BIGNUM * value)
+{
+	buffer_put_bignum2(&outgoing_packet, value);
+}
 
 /*
  * Finalizes and sends the packet.  If the encryption key has been set,
@@ -348,7 +440,7 @@ packet_put_bignum(BIGNUM * value)
  */
 
 void
-packet_send()
+packet_send1()
 {
 	char buf[8], *cp;
 	int i, padding, len;
@@ -419,6 +511,139 @@ packet_send()
 }
 
 /*
+ * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
+ */
+void
+packet_send2()
+{
+	unsigned char *macbuf = NULL;
+	char *cp;
+	unsigned int packet_length = 0;
+	unsigned int i, padlen, len;
+	u_int32_t rand = 0;
+        static unsigned int seqnr = 0;
+	int type;
+	Enc *enc   = NULL;
+	Mac *mac   = NULL;
+	Comp *comp = NULL;
+	int block_size;
+
+	if (kex != NULL) {
+		enc  = &kex->enc[MODE_OUT];
+		mac  = &kex->mac[MODE_OUT];
+		comp = &kex->comp[MODE_OUT];
+	}
+	block_size = enc ? enc->block_size : 8;
+
+	cp = buffer_ptr(&outgoing_packet);
+	type = cp[5] & 0xff;
+
+#ifdef PACKET_DEBUG
+	fprintf(stderr, "plain:     ");
+	buffer_dump(&outgoing_packet);
+#endif
+
+	if (comp && comp->enabled) {
+		len = buffer_len(&outgoing_packet);
+		/* skip header, compress only payload */
+		buffer_consume(&outgoing_packet, 5);
+		buffer_clear(&compression_buffer);
+		buffer_compress(&outgoing_packet, &compression_buffer);
+		buffer_clear(&outgoing_packet);
+		buffer_append(&outgoing_packet, "\0\0\0\0\0", 5);
+		buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer),
+		    buffer_len(&compression_buffer));
+		DBG(debug("compression: raw %d compressed %d", len,
+		    buffer_len(&outgoing_packet)));
+	}
+
+	/* sizeof (packet_len + pad_len + payload) */
+	len = buffer_len(&outgoing_packet);
+
+	/*
+	 * calc size of padding, alloc space, get random data,
+	 * minimum padding is 4 bytes
+	 */
+	padlen = block_size - (len % block_size);
+	if (padlen < 4)
+		padlen += block_size;
+	buffer_append_space(&outgoing_packet, &cp, padlen);
+	if (enc && enc->type != SSH_CIPHER_NONE) {
+		for (i = 0; i < padlen; i++) {
+			if (i % 4 == 0)
+				rand = arc4random();
+			cp[i] = rand & 0xff;
+			rand <<= 8;
+		}
+	}
+	/* packet_length includes payload, padding and padding length field */
+	packet_length = buffer_len(&outgoing_packet) - 4;
+	cp = buffer_ptr(&outgoing_packet);
+	PUT_32BIT(cp, packet_length);
+	cp[4] = padlen & 0xff;
+	DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen));
+
+	/* compute MAC over seqnr and packet(length fields, payload, padding) */
+	if (mac && mac->enabled) {
+		macbuf = hmac( mac->md, seqnr,
+		    (unsigned char *) buffer_ptr(&outgoing_packet),
+		    buffer_len(&outgoing_packet),
+		    mac->key, mac->key_len
+		);
+		DBG(debug("done calc HMAC out #%d", seqnr));
+	}
+	/* encrypt packet and append to output buffer. */
+	buffer_append_space(&output, &cp, buffer_len(&outgoing_packet));
+	packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
+	    buffer_len(&outgoing_packet));
+	/* append unencrypted MAC */
+	if (mac && mac->enabled)
+		buffer_append(&output, (char *)macbuf, mac->mac_len);
+#ifdef PACKET_DEBUG
+	fprintf(stderr, "encrypted: ");
+	buffer_dump(&output);
+#endif
+        /* increment sequence number for outgoing packets */
+        if (++seqnr == 0)
+                log("outgoing seqnr wraps around");
+	buffer_clear(&outgoing_packet);
+
+	if (type == SSH2_MSG_NEWKEYS) {
+		if (kex==NULL || mac==NULL || enc==NULL || comp==NULL)
+			fatal("packet_send2: no KEX");
+		if (mac->md != NULL)
+			mac->enabled = 1;
+		debug("cipher_set_key_iv send_context");
+		cipher_set_key_iv(&send_context, enc->type,
+		    enc->key, enc->key_len,
+		    enc->iv, enc->iv_len);
+		clear_enc_keys(enc, kex->we_need);
+		if (comp->type != 0 && comp->enabled == 0) {
+			comp->enabled = 1;
+			if (! packet_compression)
+				packet_start_compression(6);
+		}
+	}
+}
+
+void
+packet_send()
+{
+	if (use_ssh2_packet_format)
+		packet_send2();
+	else
+		packet_send1();
+	DBG(debug("packet_send done"));
+}
+
+void
+packet_send_and_wait()
+{
+	packet_send();
+	packet_write_wait();
+}
+
+/*
  * Waits until a packet has been received, and returns its type.  Note that
  * no other data is processed until this returns, so this function should not
  * be used during the interactive session.
@@ -430,6 +655,7 @@ packet_read(int *payload_len_ptr)
 	int type, len;
 	fd_set set;
 	char buf[8192];
+	DBG(debug("packet_read()"));
 
 	/* Since we are blocking, ensure that all written packets have been sent. */
 	packet_write_wait();
@@ -483,7 +709,7 @@ packet_read_expect(int *payload_len_ptr, int expected_type)
 	type = packet_read(payload_len_ptr);
 	if (type != expected_type)
 		packet_disconnect("Protocol error: expected packet type %d, got %d",
-				  expected_type, type);
+		    expected_type, type);
 }
 
 /* Checks if a full packet is available in the data received so far via
@@ -502,15 +728,13 @@ packet_read_expect(int *payload_len_ptr, int expected_type)
  */
 
 int
-packet_read_poll(int *payload_len_ptr)
+packet_read_poll1(int *payload_len_ptr)
 {
 	unsigned int len, padded_len;
 	unsigned char *ucp;
-	char buf[8], *cp, *msg;
+	char buf[8], *cp;
 	unsigned int checksum, stored_checksum;
 
-restart:
-
 	/* Check if input size is less than minimum packet size. */
 	if (buffer_len(&input) < 4 + 8)
 		return SSH_MSG_NONE;
@@ -543,7 +767,7 @@ restart:
 
 	/* Compute packet checksum. */
 	checksum = crc32((unsigned char *) buffer_ptr(&incoming_packet),
-			 buffer_len(&incoming_packet) - 4);
+	    buffer_len(&incoming_packet) - 4);
 
 	/* Skip padding. */
 	buffer_consume(&incoming_packet, 8 - len % 8);
@@ -552,7 +776,7 @@ restart:
 
 	if (len != buffer_len(&incoming_packet))
 		packet_disconnect("packet_read_poll: len %d != buffer_len %d.",
-				  len, buffer_len(&incoming_packet));
+		    len, buffer_len(&incoming_packet));
 
 	ucp = (unsigned char *) buffer_ptr(&incoming_packet) + len - 4;
 	stored_checksum = GET_32BIT(ucp);
@@ -566,7 +790,7 @@ restart:
 		buffer_uncompress(&incoming_packet, &compression_buffer);
 		buffer_clear(&incoming_packet);
 		buffer_append(&incoming_packet, buffer_ptr(&compression_buffer),
-			      buffer_len(&compression_buffer));
+		    buffer_len(&compression_buffer));
 	}
 	/* Get packet type. */
 	buffer_get(&incoming_packet, &buf[0], 1);
@@ -574,29 +798,208 @@ restart:
 	/* Return length of payload (without type field). */
 	*payload_len_ptr = buffer_len(&incoming_packet);
 
-	/* Handle disconnect message. */
-	if ((unsigned char) buf[0] == SSH_MSG_DISCONNECT) {
-		msg = packet_get_string(NULL);
-		log("Received disconnect: %.900s", msg);
-		xfree(msg);
-		fatal_cleanup();
-	}	
-
-	/* Ignore ignore messages. */
-	if ((unsigned char) buf[0] == SSH_MSG_IGNORE)
-		goto restart;
-
-	/* Send debug messages as debugging output. */
-	if ((unsigned char) buf[0] == SSH_MSG_DEBUG) {
-		msg = packet_get_string(NULL);
-		debug("Remote: %.900s", msg);
-		xfree(msg);
-		goto restart;
-	}
 	/* Return type. */
 	return (unsigned char) buf[0];
 }
 
+int
+packet_read_poll2(int *payload_len_ptr)
+{
+	unsigned int padlen, need;
+	unsigned char buf[8], *macbuf;
+	unsigned char *ucp;
+	char *cp;
+	static unsigned int packet_length = 0;
+	static unsigned int seqnr = 0;
+	int type;
+	int maclen, block_size;
+	Enc *enc   = NULL;
+	Mac *mac   = NULL;
+	Comp *comp = NULL;
+
+	if (kex != NULL) {
+		enc  = &kex->enc[MODE_IN];
+		mac  = &kex->mac[MODE_IN];
+		comp = &kex->comp[MODE_IN];
+	}
+	maclen = mac && mac->enabled ? mac->mac_len : 0;
+	block_size = enc ? enc->block_size : 8;
+
+	if (packet_length == 0) {
+		/*
+		 * check if input size is less than the cipher block size,
+		 * decrypt first block and extract length of incoming packet
+		 */
+		if (buffer_len(&input) < block_size)
+			return SSH_MSG_NONE;
+		buffer_clear(&incoming_packet);
+		buffer_append_space(&incoming_packet, &cp, block_size);
+		packet_decrypt(&receive_context, cp, buffer_ptr(&input),
+		    block_size);
+		ucp = (unsigned char *) buffer_ptr(&incoming_packet);
+		packet_length = GET_32BIT(ucp);
+		if (packet_length < 1 + 4 || packet_length > 256 * 1024) {
+			buffer_dump(&incoming_packet);
+			packet_disconnect("Bad packet length %d.", packet_length);
+		}
+		DBG(debug("input: packet len %d", packet_length+4));
+		buffer_consume(&input, block_size);
+	}
+	/* we have a partial packet of block_size bytes */
+	need = 4 + packet_length - block_size;
+	DBG(debug("partial packet %d, need %d, maclen %d", block_size,
+	    need, maclen));
+	if (need % block_size != 0)
+		fatal("padding error: need %d block %d mod %d",
+		    need, block_size, need % block_size);
+	/*
+	 * check if the entire packet has been received and
+	 * decrypt into incoming_packet
+	 */
+	if (buffer_len(&input) < need + maclen)
+		return SSH_MSG_NONE;
+#ifdef PACKET_DEBUG
+	fprintf(stderr, "read_poll enc/full: ");
+	buffer_dump(&input);
+#endif
+	buffer_append_space(&incoming_packet, &cp, need);
+	packet_decrypt(&receive_context, cp, buffer_ptr(&input), need);
+	buffer_consume(&input, need);
+	/*
+	 * compute MAC over seqnr and packet,
+	 * increment sequence number for incoming packet
+	 */
+        if (mac && mac->enabled) {
+		macbuf = hmac( mac->md, seqnr,
+		    (unsigned char *) buffer_ptr(&incoming_packet),
+		    buffer_len(&incoming_packet),
+		    mac->key, mac->key_len
+		);
+		if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0)
+			packet_disconnect("Corrupted HMAC on input.");
+		DBG(debug("HMAC #%d ok", seqnr));
+		buffer_consume(&input, mac->mac_len);
+	}
+        if (++seqnr == 0)
+                log("incoming seqnr wraps around");
+
+	/* get padlen */
+	cp = buffer_ptr(&incoming_packet) + 4;
+	padlen = *cp & 0xff;
+	DBG(debug("input: padlen %d", padlen));
+	if (padlen < 4)
+		packet_disconnect("Corrupted padlen %d on input.", padlen);
+
+	/* skip packet size + padlen, discard padding */
+	buffer_consume(&incoming_packet, 4 + 1);
+	buffer_consume_end(&incoming_packet, padlen);
+
+	DBG(debug("input: len before de-compress %d", buffer_len(&incoming_packet)));
+	if (comp && comp->enabled) {
+		buffer_clear(&compression_buffer);
+		buffer_uncompress(&incoming_packet, &compression_buffer);
+		buffer_clear(&incoming_packet);
+		buffer_append(&incoming_packet, buffer_ptr(&compression_buffer),
+		    buffer_len(&compression_buffer));
+		DBG(debug("input: len after de-compress %d", buffer_len(&incoming_packet)));
+	}
+	/*
+	 * get packet type, implies consume.
+	 * return length of payload (without type field)
+	 */
+	buffer_get(&incoming_packet, (char *)&buf[0], 1);
+	*payload_len_ptr = buffer_len(&incoming_packet);
+
+	/* reset for next packet */
+	packet_length = 0;
+
+	/* extract packet type */
+	type = (unsigned char)buf[0];
+
+	if (type == SSH2_MSG_NEWKEYS) {
+		if (kex==NULL || mac==NULL || enc==NULL || comp==NULL)
+			fatal("packet_read_poll2: no KEX");
+		if (mac->md != NULL)
+			mac->enabled = 1;
+		debug("cipher_set_key_iv receive_context");
+		cipher_set_key_iv(&receive_context, enc->type,
+		    enc->key, enc->key_len,
+		    enc->iv, enc->iv_len);
+		clear_enc_keys(enc, kex->we_need);
+		if (comp->type != 0 && comp->enabled == 0) {
+			comp->enabled = 1;
+			if (! packet_compression)
+				packet_start_compression(6);
+		}
+	}
+
+#ifdef PACKET_DEBUG
+	fprintf(stderr, "read/plain[%d]:\r\n",type);
+	buffer_dump(&incoming_packet);
+#endif
+	return (unsigned char)type;
+}
+
+int
+packet_read_poll(int *payload_len_ptr)
+{
+	char *msg;
+	for (;;) {
+		int type = use_ssh2_packet_format ?
+		    packet_read_poll2(payload_len_ptr):
+		    packet_read_poll1(payload_len_ptr);
+
+		if(compat20) {
+			int reason;
+			if (type != 0)
+				DBG(debug("received packet type %d", type));
+			switch(type) {
+			case SSH2_MSG_IGNORE:
+				break;
+			case SSH2_MSG_DEBUG:
+				packet_get_char();
+				msg = packet_get_string(NULL);
+				debug("Remote: %.900s", msg);
+				xfree(msg);
+				msg = packet_get_string(NULL);
+				xfree(msg);
+				break;
+			case SSH2_MSG_DISCONNECT:
+				reason = packet_get_int();
+				msg = packet_get_string(NULL);
+				log("Received disconnect: %d: %.900s", reason, msg);
+				xfree(msg);
+				fatal_cleanup();
+				break;
+			default:
+				return type;
+				break;
+			}	
+		} else {
+			switch(type) {
+			case SSH_MSG_IGNORE:
+				break;
+			case SSH_MSG_DEBUG:
+				msg = packet_get_string(NULL);
+				debug("Remote: %.900s", msg);
+				xfree(msg);
+				break;
+			case SSH_MSG_DISCONNECT:
+				msg = packet_get_string(NULL);
+				log("Received disconnect: %.900s", msg);
+				fatal_cleanup();
+				xfree(msg);
+				break;
+			default:
+				if (type != 0)
+					DBG(debug("received packet type %d", type));
+				return type;
+				break;
+			}	
+		}
+	}
+}
+
 /*
  * Buffers the given amount of input characters.  This is intended to be used
  * together with packet_read_poll.
@@ -637,6 +1040,21 @@ packet_get_bignum(BIGNUM * value, int *length_ptr)
 	*length_ptr = buffer_get_bignum(&incoming_packet, value);
 }
 
+void
+packet_get_bignum2(BIGNUM * value, int *length_ptr)
+{
+	*length_ptr = buffer_get_bignum2(&incoming_packet, value);
+}
+
+char *
+packet_get_raw(int *length_ptr)
+{
+	int bytes = buffer_len(&incoming_packet);
+	if (length_ptr != NULL)
+		*length_ptr = bytes;
+	return buffer_ptr(&incoming_packet);
+}
+
 /*
  * Returns a string from the packet data.  The string is allocated using
  * xmalloc; it is the responsibility of the calling program to free it when
@@ -701,8 +1119,15 @@ packet_disconnect(const char *fmt,...)
 	va_end(args);
 
 	/* Send the disconnect message to the other side, and wait for it to get sent. */
-	packet_start(SSH_MSG_DISCONNECT);
-	packet_put_string(buf, strlen(buf));
+	if (compat20) {
+		packet_start(SSH2_MSG_DISCONNECT);
+		packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
+		packet_put_cstring(buf);
+		packet_put_cstring("");
+	} else {
+		packet_start(SSH_MSG_DISCONNECT);
+		packet_put_string(buf, strlen(buf));
+	}
 	packet_send();
 	packet_write_wait();
 
@@ -833,7 +1258,8 @@ packet_set_maxsize(int s)
 {
 	static int called = 0;
 	if (called) {
-		log("packet_set_maxsize: called twice: old %d new %d", max_packet_size, s);
+		log("packet_set_maxsize: called twice: old %d new %d",
+		    max_packet_size, s);
 		return -1;
 	}
 	if (s < 4 * 1024 || s > 1024 * 1024) {
diff --git a/packet.h b/packet.h
index d1fc41dd..39c0edea 100644
--- a/packet.h
+++ b/packet.h
@@ -13,7 +13,7 @@
  * 
  */
 
-/* RCSID("$Id: packet.h,v 1.10 2000/03/17 12:40:16 damien Exp $"); */
+/* RCSID("$Id: packet.h,v 1.11 2000/04/04 04:39:03 damien Exp $"); */
 
 #ifndef PACKET_H
 #define PACKET_H
@@ -90,9 +90,12 @@ void    packet_put_int(unsigned int value);
 
 /* Appends an arbitrary precision integer to packet data. */
 void    packet_put_bignum(BIGNUM * value);
+void    packet_put_bignum2(BIGNUM * value);
 
 /* Appends a string to packet data. */
 void    packet_put_string(const char *buf, unsigned int len);
+void    packet_put_cstring(const char *str);
+void    packet_put_raw(const char *buf, unsigned int len);
 
 /*
  * Finalizes and sends the packet.  If the encryption key has been set,
@@ -136,6 +139,8 @@ unsigned int packet_get_int(void);
  * must have been initialized before this call.
  */
 void    packet_get_bignum(BIGNUM * value, int *length_ptr);
+void    packet_get_bignum2(BIGNUM * value, int *length_ptr);
+char	*packet_get_raw(int *length_ptr);
 
 /*
  * Returns a string from the packet data.  The string is allocated using
@@ -202,4 +207,7 @@ do { \
 int	packet_connection_is_on_socket(void);
 int	packet_connection_is_ipv4(void);
 
+/* enable SSH2 packet format */
+void	packet_set_ssh2_format(void);
+
 #endif				/* PACKET_H */