*/
#include "includes.h"
-RCSID("$OpenBSD: packet.c,v 1.57 2001/04/03 23:32:12 markus Exp $");
+RCSID("$OpenBSD: packet.c,v 1.65 2001/06/07 20:23:04 markus Exp $");
#include "xmalloc.h"
#include "buffer.h"
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;
/* 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;
/* 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
-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)
-{
- 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.
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);
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();
}
packet_set_protocol_flags(u_int protocol_flags)
{
remote_protocol_flags = protocol_flags;
- channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0);
}
/* Returns the remote protocol flags set earlier by the above function. */
* Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
*/
-/*** XXXXX todo: kex means re-init */
void
-packet_start_compression(int level)
+packet_init_compression()
{
- if (packet_compression)
- fatal("Compression already enabled.");
- packet_compression = 1;
+ if (compression_buffer_ready == 1)
+ return;
+ compression_buffer_ready = 1;
buffer_init(&compression_buffer);
- buffer_compress_init(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)
+packet_start_compression(int level)
{
- /*
- * 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);
+ if (packet_compression && !compat20)
+ fatal("Compression already enabled.");
+ packet_compression = 1;
+ packet_init_compression();
+ buffer_compress_init_send(level);
+ buffer_compress_init_recv();
}
/*
* 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)
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];
+ u_char buf[9];
+ int len;
- 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);
-}
-
-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)
{
void
packet_put_cstring(const char *str)
{
- buffer_put_string(&outgoing_packet, str, strlen(str));
+ buffer_put_cstring(&outgoing_packet, 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)
{
/* 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)
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
cc = (mode == MODE_OUT) ? &send_context : &receive_context;
if (newkeys[mode] != NULL) {
debug("newkeys: rekeying");
+ /* todo: free old keys, reset compression/cipher-ctxt; */
memset(cc, 0, sizeof(*cc));
- // free old keys, reset compression cipher-contexts;
+ enc = &newkeys[mode]->enc;
+ mac = &newkeys[mode]->mac;
+ comp = &newkeys[mode]->comp;
+ memset(mac->key, 0, mac->key_len);
+ xfree(enc->name);
+ xfree(enc->iv);
+ xfree(enc->key);
+ xfree(mac->name);
+ xfree(mac->key);
+ xfree(comp->name);
+ xfree(newkeys[mode]);
}
newkeys[mode] = kex_get_newkeys(mode);
if (newkeys[mode] == NULL)
DBG(debug("cipher_init_context: %d", mode));
cipher_init(cc, enc->cipher, enc->key, enc->cipher->key_len,
enc->iv, enc->cipher->block_size);
- clear_enc_keys(enc, enc->cipher->key_len);
+ 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);
}
}
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;
}
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: ");
}
/* 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) */
}
/* 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)
void
packet_send()
{
- if (use_ssh2_packet_format)
+ if (compat20)
packet_send2();
else
packet_send1();
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
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. */
/* 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
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));
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);
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
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;
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);
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,
/* 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);
* 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:
break;
}
} else {
+ type = packet_read_poll1(payload_len_ptr);
switch(type) {
case SSH_MSG_IGNORE:
break;
xfree(msg);
break;
default:
- if (type != 0)
+ if (type)
DBG(debug("received packet type %d", type));
return type;
break;
packet_put_cstring("");
} else {
packet_start(SSH_MSG_DISCONNECT);
- packet_put_string(buf, strlen(buf));
+ packet_put_cstring(buf);
}
packet_send();
packet_write_wait();
/*
* 9.2. Ignored Data Message
- *
+ *
* byte SSH_MSG_IGNORE
* string data
- *
+ *
* All implementations MUST understand (and ignore) this message at any
* time (after receiving the protocol version). No implementation is
* required to send them. This message can be used as an additional
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);
andersk / openssh.git / blobdiff