- markus@cvs.openbsd.org 2001/05/28 23:58:35

     [packet.c packet.h sshconnect.c sshd.c]
     remove some lines, simplify.

1 files changed, 58 insertions, 147 deletions

diff --git a/packet.c b/packet.c
index e816cb947..bf8fa549e 100644
--- a/packet.c
+++ b/packet.c
@@ -37,7 +37,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: packet.c,v 1.61 2001/04/05 10:42:51 markus Exp $");
+RCSID("$OpenBSD: packet.c,v 1.62 2001/05/28 23:58:35 markus Exp $");
 
 #include "xmalloc.h"
 #include "buffer.h"
@@ -75,12 +75,6 @@ RCSID("$OpenBSD: packet.c,v 1.61 2001/04/05 10:42:51 markus Exp $");
 static int connection_in = -1;
 static int connection_out = -1;
 
-/*
- * Cipher type.  This value is only used to determine whether to pad the
- * packets with zeroes or random data.
- */
-static int cipher_type = SSH_CIPHER_NONE;
-
 /* Protocol flags for the remote side. */
 static u_int remote_protocol_flags = 0;
 
@@ -118,20 +112,9 @@ 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 */
 Newkeys *newkeys[MODE_MAX];
 
-void
-packet_set_ssh2_format(void)
-{
-	DBG(debug("use_ssh2_packet_format"));
-	use_ssh2_packet_format = 1;
-	newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL;
-}
-
 /*
  * Sets the descriptors used for communication.  Disables encryption until
  * packet_set_encryption_key is called.
@@ -144,9 +127,9 @@ packet_set_connection(int fd_in, int fd_out)
 		fatal("packet_set_connection: cannot load cipher 'none'");
 	connection_in = fd_in;
 	connection_out = fd_out;
-	cipher_type = SSH_CIPHER_NONE;
 	cipher_init(&send_context, none, (u_char *) "", 0, NULL, 0);
 	cipher_init(&receive_context, none, (u_char *) "", 0, NULL, 0);
+	newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL;
 	if (!initialized) {
 		initialized = 1;
 		buffer_init(&input);
@@ -290,7 +273,7 @@ packet_init_compression()
 void
 packet_start_compression(int level)
 {
-	if (packet_compression && !use_ssh2_packet_format)
+	if (packet_compression && !compat20)
 		fatal("Compression already enabled.");
 	packet_compression = 1;
 	packet_init_compression();
@@ -299,43 +282,10 @@ packet_start_compression(int level)
 }
 
 /*
- * Encrypts the given number of bytes, copying from src to dest. bytes is
- * known to be a multiple of 8.
- */
-
-void
-packet_encrypt(CipherContext * cc, void *dest, void *src,
-    u_int bytes)
-{
-	cipher_encrypt(cc, dest, src, bytes);
-}
-
-/*
- * Decrypts the given number of bytes, copying from src to dest. bytes is
- * known to be a multiple of 8.
- */
-
-void
-packet_decrypt(CipherContext *context, void *dest, void *src, u_int bytes)
-{
-	/*
-	 * Cryptographic attack detector for ssh - Modifications for packet.c
-	 * (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com)
-	 */
-	if (!compat20 &&
-	    context->cipher->number != SSH_CIPHER_NONE &&
-	    detect_attack(src, bytes, NULL) == DEATTACK_DETECTED)
-		packet_disconnect("crc32 compensation attack: network attack detected");
-
-	cipher_decrypt(context, dest, src, bytes);
-}
-
-/*
  * Causes any further packets to be encrypted using the given key.  The same
  * key is used for both sending and reception.  However, both directions are
  * encrypted independently of each other.
  */
-
 void
 packet_set_encryption_key(const u_char *key, u_int keylen,
     int number)
@@ -349,61 +299,33 @@ packet_set_encryption_key(const u_char *key, u_int keylen,
 	cipher_init(&send_context, cipher, key, keylen, NULL, 0);
 }
 
-/* Starts constructing a packet to send. */
-
+/* Start constructing a packet to send. */
 void
-packet_start1(int type)
+packet_start(u_char type)
 {
-	char buf[9];
-
-	buffer_clear(&outgoing_packet);
-	memset(buf, 0, 8);
-	buf[8] = 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);
-}
+	u_char buf[9];
+	int len;
 
-void
-packet_start(int type)
-{
 	DBG(debug("packet_start[%d]", type));
-	if (use_ssh2_packet_format)
-		packet_start2(type);
-	else
-		packet_start1(type);
+	len = compat20 ? 6 : 9;
+	memset(buf, 0, len - 1);
+	buf[len - 1] = type;
+	buffer_clear(&outgoing_packet);
+	buffer_append(&outgoing_packet, buf, len);
 }
 
-/* Appends a character to the packet data. */
-
+/* Append payload. */
 void
 packet_put_char(int value)
 {
 	char ch = value;
 	buffer_append(&outgoing_packet, &ch, 1);
 }
-
-/* Appends an integer to the packet data. */
-
 void
 packet_put_int(u_int value)
 {
 	buffer_put_int(&outgoing_packet, value);
 }
-
-/* Appends a string to packet data. */
-
 void
 packet_put_string(const char *buf, u_int len)
 {
@@ -414,16 +336,11 @@ packet_put_cstring(const char *str)
 {
 	buffer_put_string(&outgoing_packet, str, strlen(str));
 }
-
 void
 packet_put_raw(const char *buf, u_int len)
 {
 	buffer_append(&outgoing_packet, buf, len);
 }
-
-
-/* Appends an arbitrary precision integer to packet data. */
-
 void
 packet_put_bignum(BIGNUM * value)
 {
@@ -468,7 +385,7 @@ packet_send1(void)
 
 	/* Insert padding. Initialized to zero in packet_start1() */
 	padding = 8 - len % 8;
-	if (cipher_type != SSH_CIPHER_NONE) {
+	if (send_context.cipher->number != SSH_CIPHER_NONE) {
 		cp = buffer_ptr(&outgoing_packet);
 		for (i = 0; i < padding; i++) {
 			if (i % 4 == 0)
@@ -494,7 +411,7 @@ packet_send1(void)
 	PUT_32BIT(buf, len);
 	buffer_append(&output, buf, 4);
 	buffer_append_space(&output, &cp, buffer_len(&outgoing_packet));
-	packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
+	cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
 		       buffer_len(&outgoing_packet));
 
 #ifdef PACKET_DEBUG
@@ -568,12 +485,11 @@ void
 packet_send2(void)
 {
 	static u_int32_t seqnr = 0;
-	u_char *macbuf = NULL;
+	u_char type, *ucp, *macbuf = NULL;
 	char *cp;
 	u_int packet_length = 0;
 	u_int i, padlen, len;
 	u_int32_t rand = 0;
-	int type;
 	Enc *enc   = NULL;
 	Mac *mac   = NULL;
 	Comp *comp = NULL;
@@ -586,8 +502,8 @@ packet_send2(void)
 	}
 	block_size = enc ? enc->cipher->block_size : 8;
 
-	cp = buffer_ptr(&outgoing_packet);
-	type = cp[5] & 0xff;
+	ucp = (u_char *) buffer_ptr(&outgoing_packet);
+	type = ucp[5];
 
 #ifdef PACKET_DEBUG
 	fprintf(stderr, "plain:     ");
@@ -633,9 +549,9 @@ packet_send2(void)
 	}
 	/* 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;
+	ucp = (u_char *)buffer_ptr(&outgoing_packet);
+	PUT_32BIT(ucp, packet_length);
+	ucp[4] = padlen;
 	DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen));
 
 	/* compute MAC over seqnr and packet(length fields, payload, padding) */
@@ -647,7 +563,7 @@ packet_send2(void)
 	}
 	/* 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),
+	cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
 	    buffer_len(&outgoing_packet));
 	/* append unencrypted MAC */
 	if (mac && mac->enabled)
@@ -668,7 +584,7 @@ packet_send2(void)
 void
 packet_send()
 {
-	if (use_ssh2_packet_format)
+	if (compat20)
 		packet_send2();
 	else
 		packet_send1();
@@ -699,7 +615,7 @@ packet_read(int *payload_len_ptr)
 	for (;;) {
 		/* Try to read a packet from the buffer. */
 		type = packet_read_poll(payload_len_ptr);
-		if (!use_ssh2_packet_format && (
+		if (!compat20 && (
 		    type == SSH_SMSG_SUCCESS
 		    || type == SSH_SMSG_FAILURE
 		    || type == SSH_CMSG_EOF
@@ -772,8 +688,8 @@ int
 packet_read_poll1(int *payload_len_ptr)
 {
 	u_int len, padded_len;
-	u_char *ucp;
-	char buf[8], *cp;
+	u_char *ucp, type;
+	char *cp;
 	u_int checksum, stored_checksum;
 
 	/* Check if input size is less than minimum packet size. */
@@ -795,10 +711,20 @@ packet_read_poll1(int *payload_len_ptr)
 	/* Consume packet length. */
 	buffer_consume(&input, 4);
 
-	/* Copy data to incoming_packet. */
+	/*
+	 * Cryptographic attack detector for ssh
+	 * (C)1998 CORE-SDI, Buenos Aires Argentina
+	 * Ariel Futoransky(futo@core-sdi.com)
+	 */
+	if (receive_context.cipher->number != SSH_CIPHER_NONE &&
+	    detect_attack(buffer_ptr(&input), padded_len, NULL) == DEATTACK_DETECTED)
+		packet_disconnect("crc32 compensation attack: network attack detected");
+
+	/* Decrypt data to incoming_packet. */
 	buffer_clear(&incoming_packet);
 	buffer_append_space(&incoming_packet, &cp, padded_len);
-	packet_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len);
+	cipher_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len);
+
 	buffer_consume(&input, padded_len);
 
 #ifdef PACKET_DEBUG
@@ -814,7 +740,6 @@ packet_read_poll1(int *payload_len_ptr)
 	buffer_consume(&incoming_packet, 8 - len % 8);
 
 	/* Test check bytes. */
-
 	if (len != buffer_len(&incoming_packet))
 		packet_disconnect("packet_read_poll: len %d != buffer_len %d.",
 		    len, buffer_len(&incoming_packet));
@@ -825,7 +750,6 @@ packet_read_poll1(int *payload_len_ptr)
 		packet_disconnect("Corrupted check bytes on input.");
 	buffer_consume_end(&incoming_packet, 4);
 
-	/* If using packet compression, decompress the packet. */
 	if (packet_compression) {
 		buffer_clear(&compression_buffer);
 		buffer_uncompress(&incoming_packet, &compression_buffer);
@@ -833,14 +757,9 @@ packet_read_poll1(int *payload_len_ptr)
 		buffer_append(&incoming_packet, buffer_ptr(&compression_buffer),
 		    buffer_len(&compression_buffer));
 	}
-	/* Get packet type. */
-	buffer_get(&incoming_packet, &buf[0], 1);
-
-	/* Return length of payload (without type field). */
+	type = buffer_get_char(&incoming_packet);
 	*payload_len_ptr = buffer_len(&incoming_packet);
-
-	/* Return type. */
-	return (u_char) buf[0];
+	return type;
 }
 
 int
@@ -849,10 +768,8 @@ packet_read_poll2(int *payload_len_ptr)
 	static u_int32_t seqnr = 0;
 	static u_int packet_length = 0;
 	u_int padlen, need;
-	u_char buf[8], *macbuf;
-	u_char *ucp;
+	u_char *macbuf, *ucp, type;
 	char *cp;
-	int type;
 	int maclen, block_size;
 	Enc *enc   = NULL;
 	Mac *mac   = NULL;
@@ -875,7 +792,7 @@ packet_read_poll2(int *payload_len_ptr)
 			return SSH_MSG_NONE;
 		buffer_clear(&incoming_packet);
 		buffer_append_space(&incoming_packet, &cp, block_size);
-		packet_decrypt(&receive_context, cp, buffer_ptr(&input),
+		cipher_decrypt(&receive_context, cp, buffer_ptr(&input),
 		    block_size);
 		ucp = (u_char *) buffer_ptr(&incoming_packet);
 		packet_length = GET_32BIT(ucp);
@@ -904,7 +821,7 @@ packet_read_poll2(int *payload_len_ptr)
 	buffer_dump(&input);
 #endif
 	buffer_append_space(&incoming_packet, &cp, need);
-	packet_decrypt(&receive_context, cp, buffer_ptr(&input), need);
+	cipher_decrypt(&receive_context, cp, buffer_ptr(&input), need);
 	buffer_consume(&input, need);
 	/*
 	 * compute MAC over seqnr and packet,
@@ -924,7 +841,7 @@ packet_read_poll2(int *payload_len_ptr)
 
 	/* get padlen */
 	cp = buffer_ptr(&incoming_packet) + 4;
-	padlen = *cp & 0xff;
+	padlen = (u_char) *cp;
 	DBG(debug("input: padlen %d", padlen));
 	if (padlen < 4)
 		packet_disconnect("Corrupted padlen %d on input.", padlen);
@@ -946,37 +863,30 @@ packet_read_poll2(int *payload_len_ptr)
 	 * 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 = (u_char)buf[0];
-
+	type = buffer_get_char(&incoming_packet);
 	if (type == SSH2_MSG_NEWKEYS)
 		set_newkeys(MODE_IN);
-
+	*payload_len_ptr = buffer_len(&incoming_packet);
 #ifdef PACKET_DEBUG
 	fprintf(stderr, "read/plain[%d]:\r\n", type);
 	buffer_dump(&incoming_packet);
 #endif
-	return (u_char)type;
+	/* reset for next packet */
+	packet_length = 0;
+	return type;
 }
 
 int
 packet_read_poll(int *payload_len_ptr)
 {
+	int reason;
+	u_char type;
 	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)
+	for (;;) {
+		if (compat20) {
+			type = packet_read_poll2(payload_len_ptr);
+			if (type)
 				DBG(debug("received packet type %d", type));
 			switch(type) {
 			case SSH2_MSG_IGNORE:
@@ -1002,6 +912,7 @@ packet_read_poll(int *payload_len_ptr)
 				break;
 			}
 		} else {
+			type = packet_read_poll1(payload_len_ptr);
 			switch(type) {
 			case SSH_MSG_IGNORE:
 				break;
@@ -1018,7 +929,7 @@ packet_read_poll(int *payload_len_ptr)
 				xfree(msg);
 				break;
 			default:
-				if (type != 0)
+				if (type)
 					DBG(debug("received packet type %d", type));
 				return type;
 				break;
@@ -1345,7 +1256,7 @@ packet_inject_ignore(int sumlen)
 	int blocksize, padlen, have, need, nb, mini, nbytes;
 	Enc *enc = NULL;
 
-	if (use_ssh2_packet_format == 0)
+	if (compat20 == 0)
 		return;
 
 	have = buffer_len(&outgoing_packet);