diff --git a/ChangeLog b/ChangeLog
index 9a9b7f5..3d1f8e0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,9 @@
    - markus@cvs.openbsd.org 2001/04/05 10:00:06
      [compat.c]
      2.3.x does old  GEX, too; report jakob@
+   - markus@cvs.openbsd.org 2001/04/05 10:39:03
+     [compress.c compress.h packet.c]
+     reset compress state per direction when rekeying.
 
 20010405
  - OpenBSD CVS Sync                                              
@@ -4876,4 +4879,4 @@
  - Wrote replacements for strlcpy and mkdtemp
  - Released 1.0pre1
 
-$Id: ChangeLog,v 1.1064 2001/04/05 23:19:21 mouring Exp $
+$Id: ChangeLog,v 1.1065 2001/04/05 23:20:46 mouring Exp $
diff --git a/compress.c b/compress.c
index e8539ba..3e41b3d 100644
--- a/compress.c
+++ b/compress.c
@@ -12,7 +12,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: compress.c,v 1.13 2001/02/08 19:30:51 itojun Exp $");
+RCSID("$OpenBSD: compress.c,v 1.14 2001/04/05 10:39:01 markus Exp $");
 
 #include "log.h"
 #include "buffer.h"
@@ -21,6 +21,8 @@
 
 static z_stream incoming_stream;
 static z_stream outgoing_stream;
+static int compress_init_send_called = 0;
+static int compress_init_recv_called = 0;
 
 /*
  * Initializes compression; level is compression level from 1 to 9
@@ -28,14 +30,24 @@
  */
 
 void
-buffer_compress_init(int level)
+buffer_compress_init_send(int level)
 {
+	if (compress_init_send_called == 1)
+		deflateEnd(&incoming_stream);
+	compress_init_send_called = 1;
 	debug("Enabling compression at level %d.", level);
 	if (level < 1 || level > 9)
 		fatal("Bad compression level %d.", level);
-	inflateInit(&incoming_stream);
 	deflateInit(&outgoing_stream, level);
 }
+void
+buffer_compress_init_recv(void)
+{
+	if (compress_init_recv_called == 1)
+		inflateEnd(&incoming_stream);
+	compress_init_recv_called = 1;
+	inflateInit(&incoming_stream);
+}
 
 /* Frees any data structures allocated for compression. */
 
@@ -50,8 +62,10 @@
 	      incoming_stream.total_out, incoming_stream.total_in,
 	      incoming_stream.total_out == 0 ? 0.0 :
 	      (double) incoming_stream.total_in / incoming_stream.total_out);
-	inflateEnd(&incoming_stream);
-	deflateEnd(&outgoing_stream);
+	if (compress_init_recv_called == 1)
+		inflateEnd(&incoming_stream);
+	if (compress_init_send_called == 1)
+		deflateEnd(&outgoing_stream);
 }
 
 /*
diff --git a/compress.h b/compress.h
index 87d592f..f90932a 100644
--- a/compress.h
+++ b/compress.h
@@ -11,7 +11,7 @@
  * called by a name other than "ssh" or "Secure Shell".
  */
 
-/* RCSID("$OpenBSD: compress.h,v 1.7 2000/12/20 19:37:22 markus Exp $"); */
+/* RCSID("$OpenBSD: compress.h,v 1.8 2001/04/05 10:39:02 markus Exp $"); */
 
 #ifndef COMPRESS_H
 #define COMPRESS_H
@@ -20,7 +20,8 @@
  * Initializes compression; level is compression level from 1 to 9 (as in
  * gzip).
  */
-void    buffer_compress_init(int level);
+void	buffer_compress_init_send(int level);
+void	buffer_compress_init_recv(void);
 
 /* Frees any data structures allocated by buffer_compress_init. */
 void    buffer_compress_uninit(void);
diff --git a/packet.c b/packet.c
index 5b5fa08..d518d0e 100644
--- a/packet.c
+++ b/packet.c
@@ -37,7 +37,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: packet.c,v 1.59 2001/04/04 23:09:18 markus Exp $");
+RCSID("$OpenBSD: packet.c,v 1.60 2001/04/05 10:39:03 markus Exp $");
 
 #include "xmalloc.h"
 #include "buffer.h"
@@ -104,6 +104,7 @@
 
 /* Scratch buffer for packet compression/decompression. */
 static Buffer compression_buffer;
+static int compression_buffer_ready = 0;
 
 /* Flag indicating whether packet compression/decompression is enabled. */
 static int packet_compression = 0;
@@ -249,7 +250,7 @@
 	buffer_free(&output);
 	buffer_free(&outgoing_packet);
 	buffer_free(&incoming_packet);
-	if (packet_compression) {
+	if (compression_buffer_ready) {
 		buffer_free(&compression_buffer);
 		buffer_compress_uninit();
 	}
@@ -277,15 +278,24 @@
  * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
  */
 
-/*** XXXXX todo: kex means re-init */
+void
+packet_init_compression()
+{
+	if (compression_buffer_ready == 1)
+		return;
+	compression_buffer_ready = 1;
+	buffer_init(&compression_buffer);
+}
+
 void
 packet_start_compression(int level)
 {
-	if (packet_compression)
+	if (packet_compression && !use_ssh2_packet_format)
 		fatal("Compression already enabled.");
 	packet_compression = 1;
-	buffer_init(&compression_buffer);
-	buffer_compress_init(level);
+	packet_init_compression();
+	buffer_compress_init_send(level);
+	buffer_compress_init_recv();
 }
 
 /*
@@ -542,9 +552,12 @@
 	memset(enc->iv,  0, enc->cipher->block_size);
 	memset(enc->key, 0, enc->cipher->key_len);
 	if (comp->type != 0 && comp->enabled == 0) {
+		packet_init_compression();
+		if (mode == MODE_OUT)
+			buffer_compress_init_send(6);
+		else
+			buffer_compress_init_recv();
 		comp->enabled = 1;
-		if (! packet_compression)
-			packet_start_compression(6);
 	}
 }