*
*
* SSH2 packet format added by Markus Friedl.
- * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
*/
#include "includes.h"
-RCSID("$OpenBSD: packet.c,v 1.65 2001/06/07 20:23:04 markus Exp $");
+RCSID("$OpenBSD: packet.c,v 1.85 2002/01/18 18:14:17 stevesk Exp $");
#include "xmalloc.h"
#include "buffer.h"
/* Session key information for Encryption and MAC */
Newkeys *newkeys[MODE_MAX];
+/* roundup current message to extra_pad bytes */
+static u_char extra_pad = 0;
+
/*
* 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_init(&send_context, none, (u_char *) "", 0, NULL, 0);
- cipher_init(&receive_context, none, (u_char *) "", 0, NULL, 0);
+ cipher_init(&send_context, none, "", 0, NULL, 0);
+ cipher_init(&receive_context, none, "", 0, NULL, 0);
newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL;
if (!initialized) {
initialized = 1;
/* Returns 1 if remote host is connected via socket, 0 if not. */
int
-packet_connection_is_on_socket()
+packet_connection_is_on_socket(void)
{
struct sockaddr_storage from, to;
socklen_t fromlen, tolen;
/* returns 1 if connection is via ipv4 */
int
-packet_connection_is_ipv4()
+packet_connection_is_ipv4(void)
{
struct sockaddr_storage to;
socklen_t tolen = sizeof(to);
/* Sets the connection into non-blocking mode. */
void
-packet_set_nonblocking()
+packet_set_nonblocking(void)
{
/* Set the socket into non-blocking mode. */
if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0)
/* Returns the socket used for reading. */
int
-packet_get_connection_in()
+packet_get_connection_in(void)
{
return connection_in;
}
/* Returns the descriptor used for writing. */
int
-packet_get_connection_out()
+packet_get_connection_out(void)
{
return connection_out;
}
/* Closes the connection and clears and frees internal data structures. */
void
-packet_close()
+packet_close(void)
{
if (!initialized)
return;
/* Returns the remote protocol flags set earlier by the above function. */
u_int
-packet_get_protocol_flags()
+packet_get_protocol_flags(void)
{
return remote_protocol_flags;
}
* Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
*/
-void
-packet_init_compression()
+static void
+packet_init_compression(void)
{
if (compression_buffer_ready == 1)
return;
buffer_put_int(&outgoing_packet, value);
}
void
-packet_put_string(const char *buf, u_int len)
+packet_put_string(const void *buf, u_int len)
{
buffer_put_string(&outgoing_packet, buf, len);
}
buffer_put_cstring(&outgoing_packet, str);
}
void
-packet_put_raw(const char *buf, u_int len)
+packet_put_raw(const void *buf, u_int len)
{
buffer_append(&outgoing_packet, buf, len);
}
* encrypts the packet before sending.
*/
-void
+static void
packet_send1(void)
{
char buf[8], *cp;
buffer_compress(&outgoing_packet, &compression_buffer);
buffer_clear(&outgoing_packet);
buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer),
- buffer_len(&compression_buffer));
+ buffer_len(&compression_buffer));
}
/* Compute packet length without padding (add checksum, remove padding). */
len = buffer_len(&outgoing_packet) + 4 - 8;
buffer_consume(&outgoing_packet, 8 - padding);
/* Add check bytes. */
- checksum = ssh_crc32((u_char *) buffer_ptr(&outgoing_packet),
+ checksum = ssh_crc32(buffer_ptr(&outgoing_packet),
buffer_len(&outgoing_packet));
PUT_32BIT(buf, checksum);
buffer_append(&outgoing_packet, buf, 4);
/* Append to output. */
PUT_32BIT(buf, len);
buffer_append(&output, buf, 4);
- buffer_append_space(&output, &cp, buffer_len(&outgoing_packet));
+ cp = buffer_append_space(&output, buffer_len(&outgoing_packet));
cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
- buffer_len(&outgoing_packet));
+ buffer_len(&outgoing_packet));
#ifdef PACKET_DEBUG
fprintf(stderr, "encrypted: ");
*/
}
-void
+static void
set_newkeys(int mode)
{
Enc *enc;
/*
* Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
*/
-void
+static void
packet_send2(void)
{
static u_int32_t seqnr = 0;
u_char type, *ucp, *macbuf = NULL;
+ u_char padlen, pad;
char *cp;
u_int packet_length = 0;
- u_int i, padlen, len;
+ u_int i, len;
u_int32_t rand = 0;
Enc *enc = NULL;
Mac *mac = NULL;
}
block_size = enc ? enc->cipher->block_size : 8;
- ucp = (u_char *) buffer_ptr(&outgoing_packet);
+ ucp = buffer_ptr(&outgoing_packet);
type = ucp[5];
#ifdef PACKET_DEBUG
padlen = block_size - (len % block_size);
if (padlen < 4)
padlen += block_size;
- buffer_append_space(&outgoing_packet, &cp, padlen);
+ if (extra_pad) {
+ /* will wrap if extra_pad+padlen > 255 */
+ extra_pad = roundup(extra_pad, block_size);
+ pad = extra_pad - ((len + padlen) % extra_pad);
+ debug("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
+ pad, len, padlen, extra_pad);
+ padlen += pad;
+ extra_pad = 0;
+ }
+ cp = buffer_append_space(&outgoing_packet, padlen);
if (enc && enc->cipher->number != SSH_CIPHER_NONE) {
/* random padding */
for (i = 0; i < padlen; i++) {
}
/* packet_length includes payload, padding and padding length field */
packet_length = buffer_len(&outgoing_packet) - 4;
- ucp = (u_char *)buffer_ptr(&outgoing_packet);
+ ucp = 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) */
if (mac && mac->enabled) {
macbuf = mac_compute(mac, seqnr,
- (u_char *) buffer_ptr(&outgoing_packet),
+ buffer_ptr(&outgoing_packet),
buffer_len(&outgoing_packet));
DBG(debug("done calc MAC out #%d", seqnr));
}
/* encrypt packet and append to output buffer. */
- buffer_append_space(&output, &cp, buffer_len(&outgoing_packet));
+ cp = buffer_append_space(&output, buffer_len(&outgoing_packet));
cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
buffer_len(&outgoing_packet));
/* append unencrypted MAC */
}
void
-packet_send()
+packet_send(void)
{
if (compat20)
packet_send2();
*/
int
-packet_read(int *payload_len_ptr)
+packet_read_seqnr(u_int32_t *seqnr_p)
{
int type, len;
fd_set *setp;
/* Stay in the loop until we have received a complete packet. */
for (;;) {
/* Try to read a packet from the buffer. */
- type = packet_read_poll(payload_len_ptr);
+ type = packet_read_poll_seqnr(seqnr_p);
if (!compat20 && (
type == SSH_SMSG_SUCCESS
|| type == SSH_SMSG_FAILURE
|| type == SSH_CMSG_EOF
|| type == SSH_CMSG_EXIT_CONFIRMATION))
- packet_integrity_check(*payload_len_ptr, 0, type);
+ packet_check_eom();
/* If we got a packet, return it. */
if (type != SSH_MSG_NONE) {
xfree(setp);
/* NOTREACHED */
}
+int
+packet_read(void)
+{
+ return packet_read_seqnr(NULL);
+}
+
/*
* Waits until a packet has been received, verifies that its type matches
* that given, and gives a fatal error and exits if there is a mismatch.
*/
void
-packet_read_expect(int *payload_len_ptr, int expected_type)
+packet_read_expect(int expected_type)
{
int type;
- type = packet_read(payload_len_ptr);
+ type = packet_read();
if (type != expected_type)
packet_disconnect("Protocol error: expected packet type %d, got %d",
expected_type, type);
* SSH_MSG_DISCONNECT is handled specially here. Also,
* SSH_MSG_IGNORE messages are skipped by this function and are never returned
* to higher levels.
- *
- * The returned payload_len does include space consumed by:
- * Packet length
- * Padding
- * Packet type
- * Check bytes
*/
-int
-packet_read_poll1(int *payload_len_ptr)
+static int
+packet_read_poll1(void)
{
u_int len, padded_len;
u_char *ucp, type;
if (buffer_len(&input) < 4 + 8)
return SSH_MSG_NONE;
/* Get length of incoming packet. */
- ucp = (u_char *) buffer_ptr(&input);
+ ucp = buffer_ptr(&input);
len = GET_32BIT(ucp);
if (len < 1 + 2 + 2 || len > 256 * 1024)
packet_disconnect("Bad packet length %d.", len);
/* Decrypt data to incoming_packet. */
buffer_clear(&incoming_packet);
- buffer_append_space(&incoming_packet, &cp, padded_len);
+ cp = buffer_append_space(&incoming_packet, padded_len);
cipher_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len);
buffer_consume(&input, padded_len);
#endif
/* Compute packet checksum. */
- checksum = ssh_crc32((u_char *) buffer_ptr(&incoming_packet),
+ checksum = ssh_crc32(buffer_ptr(&incoming_packet),
buffer_len(&incoming_packet) - 4);
/* Skip padding. */
/* Test check bytes. */
if (len != buffer_len(&incoming_packet))
- packet_disconnect("packet_read_poll: len %d != buffer_len %d.",
+ packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
len, buffer_len(&incoming_packet));
- ucp = (u_char *) buffer_ptr(&incoming_packet) + len - 4;
+ ucp = (u_char *)buffer_ptr(&incoming_packet) + len - 4;
stored_checksum = GET_32BIT(ucp);
if (checksum != stored_checksum)
packet_disconnect("Corrupted check bytes on input.");
buffer_len(&compression_buffer));
}
type = buffer_get_char(&incoming_packet);
- *payload_len_ptr = buffer_len(&incoming_packet);
return type;
}
-int
-packet_read_poll2(int *payload_len_ptr)
+static int
+packet_read_poll2(u_int32_t *seqnr_p)
{
static u_int32_t seqnr = 0;
static u_int packet_length = 0;
if (buffer_len(&input) < block_size)
return SSH_MSG_NONE;
buffer_clear(&incoming_packet);
- buffer_append_space(&incoming_packet, &cp, block_size);
+ cp = buffer_append_space(&incoming_packet, block_size);
cipher_decrypt(&receive_context, cp, buffer_ptr(&input),
block_size);
- ucp = (u_char *) buffer_ptr(&incoming_packet);
+ ucp = buffer_ptr(&incoming_packet);
packet_length = GET_32BIT(ucp);
if (packet_length < 1 + 4 || packet_length > 256 * 1024) {
buffer_dump(&incoming_packet);
fprintf(stderr, "read_poll enc/full: ");
buffer_dump(&input);
#endif
- buffer_append_space(&incoming_packet, &cp, need);
+ cp = buffer_append_space(&incoming_packet, need);
cipher_decrypt(&receive_context, cp, buffer_ptr(&input), need);
buffer_consume(&input, need);
/*
*/
if (mac && mac->enabled) {
macbuf = mac_compute(mac, seqnr,
- (u_char *) buffer_ptr(&incoming_packet),
+ buffer_ptr(&incoming_packet),
buffer_len(&incoming_packet));
if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0)
packet_disconnect("Corrupted MAC on input.");
DBG(debug("MAC #%d ok", seqnr));
buffer_consume(&input, mac->mac_len);
}
+ if (seqnr_p != NULL)
+ *seqnr_p = seqnr;
if (++seqnr == 0)
log("incoming seqnr wraps around");
/* get padlen */
- cp = buffer_ptr(&incoming_packet) + 4;
+ cp = buffer_ptr(&incoming_packet);
+ cp += 4;
padlen = (u_char) *cp;
DBG(debug("input: padlen %d", padlen));
if (padlen < 4)
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);
}
int
-packet_read_poll(int *payload_len_ptr)
+packet_read_poll_seqnr(u_int32_t *seqnr_p)
{
- int reason;
+ int reason, seqnr;
u_char type;
char *msg;
for (;;) {
if (compat20) {
- type = packet_read_poll2(payload_len_ptr);
+ type = packet_read_poll2(seqnr_p);
if (type)
DBG(debug("received packet type %d", type));
- switch(type) {
+ switch (type) {
case SSH2_MSG_IGNORE:
break;
case SSH2_MSG_DEBUG:
xfree(msg);
fatal_cleanup();
break;
+ case SSH2_MSG_UNIMPLEMENTED:
+ seqnr = packet_get_int();
+ debug("Received SSH2_MSG_UNIMPLEMENTED for %d", seqnr);
+ break;
default:
return type;
break;
}
} else {
- type = packet_read_poll1(payload_len_ptr);
- switch(type) {
+ type = packet_read_poll1();
+ switch (type) {
case SSH_MSG_IGNORE:
break;
case SSH_MSG_DEBUG:
}
}
+int
+packet_read_poll(void)
+{
+ return packet_read_poll_seqnr(NULL);
+}
+
/*
* Buffers the given amount of input characters. This is intended to be used
* together with packet_read_poll.
/* Returns a character from the packet. */
u_int
-packet_get_char()
+packet_get_char(void)
{
char ch;
buffer_get(&incoming_packet, &ch, 1);
/* Returns an integer from the packet data. */
u_int
-packet_get_int()
+packet_get_int(void)
{
return buffer_get_int(&incoming_packet);
}
*/
void
-packet_get_bignum(BIGNUM * value, int *length_ptr)
+packet_get_bignum(BIGNUM * value)
{
- *length_ptr = buffer_get_bignum(&incoming_packet, value);
+ buffer_get_bignum(&incoming_packet, value);
}
void
-packet_get_bignum2(BIGNUM * value, int *length_ptr)
+packet_get_bignum2(BIGNUM * value)
{
- *length_ptr = buffer_get_bignum2(&incoming_packet, value);
+ buffer_get_bignum2(&incoming_packet, value);
}
-char *
+void *
packet_get_raw(int *length_ptr)
{
int bytes = buffer_len(&incoming_packet);
* integer into which the length of the string is stored.
*/
-char *
+void *
packet_get_string(u_int *length_ptr)
{
return buffer_get_string(&incoming_packet, length_ptr);
packet_write_wait();
/* Stop listening for connections. */
- channel_stop_listening();
+ channel_close_all();
/* Close the connection. */
packet_close();
/* Checks if there is any buffered output, and tries to write some of the output. */
void
-packet_write_poll()
+packet_write_poll(void)
{
int len = buffer_len(&output);
if (len > 0) {
*/
void
-packet_write_wait()
+packet_write_wait(void)
{
fd_set *setp;
/* Returns true if there is buffered data to write to the connection. */
int
-packet_have_data_to_write()
+packet_have_data_to_write(void)
{
return buffer_len(&output) != 0;
}
/* Returns true if there is not too much data to write to the connection. */
int
-packet_not_very_much_data_to_write()
+packet_not_very_much_data_to_write(void)
{
if (interactive_mode)
return buffer_len(&output) < 16384;
/* Returns true if the current connection is interactive. */
int
-packet_is_interactive()
+packet_is_interactive(void)
{
return interactive_mode;
}
log("packet_set_maxsize: bad size %d", s);
return -1;
}
- log("packet_set_maxsize: setting to %d", s);
+ called = 1;
+ debug("packet_set_maxsize: setting to %d", s);
max_packet_size = s;
return s;
}
+/* roundup current message to pad bytes */
+void
+packet_add_padding(u_char pad)
+{
+ extra_pad = pad;
+}
+
/*
* 9.2. Ignored Data Message
*
* required to send them. This message can be used as an additional
* protection measure against advanced traffic analysis techniques.
*/
-/* size of current + ignore message should be n*sumlen bytes (w/o mac) */
-void
-packet_inject_ignore(int sumlen)
-{
- int blocksize, padlen, have, need, nb, mini, nbytes;
- Enc *enc = NULL;
-
- if (compat20 == 0)
- return;
-
- have = buffer_len(&outgoing_packet);
- debug2("packet_inject_ignore: current %d", have);
- if (newkeys[MODE_OUT] != NULL)
- enc = &newkeys[MODE_OUT]->enc;
- blocksize = enc ? enc->cipher->block_size : 8;
- padlen = blocksize - (have % blocksize);
- if (padlen < 4)
- padlen += blocksize;
- have += padlen;
- have /= blocksize; /* # of blocks for current message */
-
- nb = roundup(sumlen, blocksize) / blocksize; /* blocks for both */
- mini = roundup(5+1+4+4, blocksize) / blocksize; /* minsize ignore msg */
- need = nb - (have % nb); /* blocks for ignore */
- if (need <= mini)
- need += nb;
- nbytes = (need - mini) * blocksize; /* size of ignore payload */
- debug2("packet_inject_ignore: block %d have %d nb %d mini %d need %d",
- blocksize, have, nb, mini, need);
-
- /* enqueue current message and append a ignore message */
- packet_send();
- packet_send_ignore(nbytes);
-}
-
void
packet_send_ignore(int nbytes)
{
packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
packet_put_int(nbytes);
- for(i = 0; i < nbytes; i++) {
+ for (i = 0; i < nbytes; i++) {
if (i % 4 == 0)
rand = arc4random();
packet_put_char(rand & 0xff);
andersk / openssh.git / blobdiff