+/* $OpenBSD: packet.c,v 1.160 2009/02/13 11:50:21 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
*/
#include "includes.h"
-RCSID("$OpenBSD: packet.c,v 1.95 2002/06/19 18:01:00 markus Exp $");
+
+#include <sys/types.h>
+#include "openbsd-compat/sys-queue.h"
+#include <sys/param.h>
+#include <sys/socket.h>
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <arpa/inet.h>
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
#include "xmalloc.h"
#include "buffer.h"
#include "packet.h"
-#include "bufaux.h"
#include "crc32.h"
-#include "getput.h"
-
#include "compress.h"
#include "deattack.h"
#include "channels.h"
-
#include "compat.h"
#include "ssh1.h"
#include "ssh2.h"
-
#include "cipher.h"
+#include "key.h"
#include "kex.h"
#include "mac.h"
#include "log.h"
#define DBG(x)
#endif
+#define PACKET_MAX_SIZE (256 * 1024)
+
/*
* This variable contains the file descriptors used for communicating with
* the other side. connection_in is used for reading; connection_out for
static int packet_compression = 0;
/* default maximum packet size */
-int max_packet_size = 32768;
+u_int max_packet_size = 32768;
/* Flag indicating whether this module has been initialized. */
static int initialized = 0;
/* Set to true if the connection is interactive. */
static int interactive_mode = 0;
+/* Set to true if we are the server side. */
+static int server_side = 0;
+
+/* Set to true if we are authenticated. */
+static int after_authentication = 0;
+
+int keep_alive_timeouts = 0;
+
+/* Set to the maximum time that we will wait to send or receive a packet */
+static int packet_timeout_ms = -1;
+
/* Session key information for Encryption and MAC */
Newkeys *newkeys[MODE_MAX];
-static u_int32_t read_seqnr = 0;
-static u_int32_t send_seqnr = 0;
+static struct packet_state {
+ u_int32_t seqnr;
+ u_int32_t packets;
+ u_int64_t blocks;
+ u_int64_t bytes;
+} p_read, p_send;
+
+static u_int64_t max_blocks_in, max_blocks_out;
+static u_int32_t rekey_limit;
/* Session key for protocol v1 */
static u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
/* roundup current message to extra_pad bytes */
static u_char extra_pad = 0;
+/* XXX discard incoming data after MAC error */
+static u_int packet_discard = 0;
+static Mac *packet_discard_mac = NULL;
+
+struct packet {
+ TAILQ_ENTRY(packet) next;
+ u_char type;
+ Buffer payload;
+};
+TAILQ_HEAD(, packet) outgoing;
+
/*
* Sets the descriptors used for communication. Disables encryption until
* packet_set_encryption_key is called.
packet_set_connection(int fd_in, int fd_out)
{
Cipher *none = cipher_by_name("none");
+
if (none == NULL)
fatal("packet_set_connection: cannot load cipher 'none'");
connection_in = fd_in;
connection_out = fd_out;
- cipher_init(&send_context, none, "", 0, NULL, 0, CIPHER_ENCRYPT);
- cipher_init(&receive_context, none, "", 0, NULL, 0, CIPHER_DECRYPT);
+ cipher_init(&send_context, none, (const u_char *)"",
+ 0, NULL, 0, CIPHER_ENCRYPT);
+ cipher_init(&receive_context, none, (const u_char *)"",
+ 0, NULL, 0, CIPHER_DECRYPT);
newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL;
if (!initialized) {
initialized = 1;
buffer_init(&output);
buffer_init(&outgoing_packet);
buffer_init(&incoming_packet);
+ TAILQ_INIT(&outgoing);
+ p_send.packets = p_read.packets = 0;
+ }
+}
+
+void
+packet_set_timeout(int timeout, int count)
+{
+ if (timeout == 0 || count == 0) {
+ packet_timeout_ms = -1;
+ return;
}
- /* Kludge: arrange the close function to be called from fatal(). */
- fatal_add_cleanup((void (*) (void *)) packet_close, NULL);
+ if ((INT_MAX / 1000) / count < timeout)
+ packet_timeout_ms = INT_MAX;
+ else
+ packet_timeout_ms = timeout * count * 1000;
+}
+
+static void
+packet_stop_discard(void)
+{
+ if (packet_discard_mac) {
+ char buf[1024];
+
+ memset(buf, 'a', sizeof(buf));
+ while (buffer_len(&incoming_packet) < PACKET_MAX_SIZE)
+ buffer_append(&incoming_packet, buf, sizeof(buf));
+ (void) mac_compute(packet_discard_mac,
+ p_read.seqnr,
+ buffer_ptr(&incoming_packet),
+ PACKET_MAX_SIZE);
+ }
+ logit("Finished discarding for %.200s", get_remote_ipaddr());
+ cleanup_exit(255);
+}
+
+static void
+packet_start_discard(Enc *enc, Mac *mac, u_int packet_length, u_int discard)
+{
+ if (enc == NULL || !cipher_is_cbc(enc->cipher))
+ packet_disconnect("Packet corrupt");
+ if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
+ packet_discard_mac = mac;
+ if (buffer_len(&input) >= discard)
+ packet_stop_discard();
+ packet_discard = discard - buffer_len(&input);
}
/* Returns 1 if remote host is connected via socket, 0 if not. */
return (cipher_get_keyiv_len(cc));
}
+
void
packet_set_iv(int mode, u_char *dat)
{
cipher_set_keyiv(cc, dat);
}
+
int
-packet_get_ssh1_cipher()
+packet_get_ssh1_cipher(void)
{
return (cipher_get_number(receive_context.cipher));
}
-
-u_int32_t
-packet_get_seqnr(int mode)
+void
+packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks, u_int32_t *packets,
+ u_int64_t *bytes)
{
- return (mode == MODE_IN ? read_seqnr : send_seqnr);
+ struct packet_state *state;
+
+ state = (mode == MODE_IN) ? &p_read : &p_send;
+ if (seqnr)
+ *seqnr = state->seqnr;
+ if (blocks)
+ *blocks = state->blocks;
+ if (packets)
+ *packets = state->packets;
+ if (bytes)
+ *bytes = state->bytes;
}
void
-packet_set_seqnr(int mode, u_int32_t seqnr)
+packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets,
+ u_int64_t bytes)
{
- if (mode == MODE_IN)
- read_seqnr = seqnr;
- else if (mode == MODE_OUT)
- send_seqnr = seqnr;
- else
- fatal("packet_set_seqnr: bad mode %d", mode);
+ struct packet_state *state;
+
+ state = (mode == MODE_IN) ? &p_read : &p_send;
+ state->seqnr = seqnr;
+ state->blocks = blocks;
+ state->packets = packets;
+ state->bytes = bytes;
}
/* returns 1 if connection is via ipv4 */
if (to.ss_family == AF_INET)
return 1;
#ifdef IPV4_IN_IPV6
- if (to.ss_family == AF_INET6 &&
+ if (to.ss_family == AF_INET6 &&
IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
return 1;
#endif
packet_set_nonblocking(void)
{
/* Set the socket into non-blocking mode. */
- if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0)
- error("fcntl O_NONBLOCK: %.100s", strerror(errno));
+ set_nonblock(connection_in);
- if (connection_out != connection_in) {
- if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0)
- error("fcntl O_NONBLOCK: %.100s", strerror(errno));
- }
+ if (connection_out != connection_in)
+ set_nonblock(connection_out);
}
/* Returns the socket used for reading. */
int number)
{
Cipher *cipher = cipher_by_number(number);
+
if (cipher == NULL)
fatal("packet_set_encryption_key: unknown cipher number %d", number);
if (keylen < 20)
packet_put_char(int value)
{
char ch = value;
+
buffer_append(&outgoing_packet, &ch, 1);
}
+
void
packet_put_int(u_int value)
{
buffer_put_int(&outgoing_packet, value);
}
+
void
packet_put_string(const void *buf, u_int len)
{
buffer_put_string(&outgoing_packet, buf, len);
}
+
void
packet_put_cstring(const char *str)
{
buffer_put_cstring(&outgoing_packet, str);
}
+
void
packet_put_raw(const void *buf, u_int len)
{
buffer_append(&outgoing_packet, buf, len);
}
+
void
packet_put_bignum(BIGNUM * value)
{
buffer_put_bignum(&outgoing_packet, value);
}
+
void
packet_put_bignum2(BIGNUM * value)
{
u_char buf[8], *cp;
int i, padding, len;
u_int checksum;
- u_int32_t rand = 0;
+ u_int32_t rnd = 0;
/*
* If using packet compression, compress the payload of the outgoing
cp = buffer_ptr(&outgoing_packet);
for (i = 0; i < padding; i++) {
if (i % 4 == 0)
- rand = arc4random();
- cp[7 - i] = rand & 0xff;
- rand >>= 8;
+ rnd = arc4random();
+ cp[7 - i] = rnd & 0xff;
+ rnd >>= 8;
}
}
buffer_consume(&outgoing_packet, 8 - padding);
/* Add check bytes. */
checksum = ssh_crc32(buffer_ptr(&outgoing_packet),
buffer_len(&outgoing_packet));
- PUT_32BIT(buf, checksum);
+ put_u32(buf, checksum);
buffer_append(&outgoing_packet, buf, 4);
#ifdef PACKET_DEBUG
#endif
/* Append to output. */
- PUT_32BIT(buf, len);
+ put_u32(buf, len);
buffer_append(&output, buf, 4);
cp = buffer_append_space(&output, buffer_len(&outgoing_packet));
cipher_crypt(&send_context, cp, buffer_ptr(&outgoing_packet),
fprintf(stderr, "encrypted: ");
buffer_dump(&output);
#endif
-
+ p_send.packets++;
+ p_send.bytes += len + buffer_len(&outgoing_packet);
buffer_clear(&outgoing_packet);
/*
- * Note that the packet is now only buffered in output. It won\'t be
+ * Note that the packet is now only buffered in output. It won't be
* actually sent until packet_write_wait or packet_write_poll is
* called.
*/
Mac *mac;
Comp *comp;
CipherContext *cc;
- int encrypt;
+ u_int64_t *max_blocks;
+ int crypt_type;
- debug("newkeys: mode %d", mode);
+ debug2("set_newkeys: mode %d", mode);
if (mode == MODE_OUT) {
cc = &send_context;
- encrypt = CIPHER_ENCRYPT;
+ crypt_type = CIPHER_ENCRYPT;
+ p_send.packets = p_send.blocks = 0;
+ max_blocks = &max_blocks_out;
} else {
cc = &receive_context;
- encrypt = CIPHER_DECRYPT;
+ crypt_type = CIPHER_DECRYPT;
+ p_read.packets = p_read.blocks = 0;
+ max_blocks = &max_blocks_in;
}
if (newkeys[mode] != NULL) {
- debug("newkeys: rekeying");
+ debug("set_newkeys: rekeying");
cipher_cleanup(cc);
enc = &newkeys[mode]->enc;
mac = &newkeys[mode]->mac;
comp = &newkeys[mode]->comp;
- memset(mac->key, 0, mac->key_len);
+ mac_clear(mac);
xfree(enc->name);
xfree(enc->iv);
xfree(enc->key);
enc = &newkeys[mode]->enc;
mac = &newkeys[mode]->mac;
comp = &newkeys[mode]->comp;
- if (mac->md != NULL)
+ if (mac_init(mac) == 0)
mac->enabled = 1;
DBG(debug("cipher_init_context: %d", mode));
cipher_init(cc, enc->cipher, enc->key, enc->key_len,
- enc->iv, enc->block_size, encrypt);
+ enc->iv, enc->block_size, crypt_type);
/* Deleting the keys does not gain extra security */
/* memset(enc->iv, 0, enc->block_size);
- memset(enc->key, 0, enc->key_len); */
- if (comp->type != 0 && comp->enabled == 0) {
+ memset(enc->key, 0, enc->key_len);
+ memset(mac->key, 0, mac->key_len); */
+ if ((comp->type == COMP_ZLIB ||
+ (comp->type == COMP_DELAYED && after_authentication)) &&
+ comp->enabled == 0) {
packet_init_compression();
if (mode == MODE_OUT)
buffer_compress_init_send(6);
buffer_compress_init_recv();
comp->enabled = 1;
}
+ /*
+ * The 2^(blocksize*2) limit is too expensive for 3DES,
+ * blowfish, etc, so enforce a 1GB limit for small blocksizes.
+ */
+ if (enc->block_size >= 16)
+ *max_blocks = (u_int64_t)1 << (enc->block_size*2);
+ else
+ *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
+ if (rekey_limit)
+ *max_blocks = MIN(*max_blocks, rekey_limit / enc->block_size);
}
/*
- * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
+ * Delayed compression for SSH2 is enabled after authentication:
+ * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
+ * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
*/
static void
-packet_send2(void)
+packet_enable_delayed_compress(void)
+{
+ Comp *comp = NULL;
+ int mode;
+
+ /*
+ * Remember that we are past the authentication step, so rekeying
+ * with COMP_DELAYED will turn on compression immediately.
+ */
+ after_authentication = 1;
+ for (mode = 0; mode < MODE_MAX; mode++) {
+ /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
+ if (newkeys[mode] == NULL)
+ continue;
+ comp = &newkeys[mode]->comp;
+ if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
+ packet_init_compression();
+ if (mode == MODE_OUT)
+ buffer_compress_init_send(6);
+ else
+ buffer_compress_init_recv();
+ comp->enabled = 1;
+ }
+ }
+}
+
+/*
+ * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
+ */
+static int
+packet_send2_wrapped(void)
{
u_char type, *cp, *macbuf = NULL;
u_char padlen, pad;
u_int packet_length = 0;
u_int i, len;
- u_int32_t rand = 0;
+ u_int32_t rnd = 0;
Enc *enc = NULL;
Mac *mac = NULL;
Comp *comp = NULL;
/* random padding */
for (i = 0; i < padlen; i++) {
if (i % 4 == 0)
- rand = arc4random();
- cp[i] = rand & 0xff;
- rand >>= 8;
+ rnd = arc4random();
+ cp[i] = rnd & 0xff;
+ rnd >>= 8;
}
} else {
/* clear padding */
/* 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);
+ put_u32(cp, packet_length);
cp[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, send_seqnr,
+ macbuf = mac_compute(mac, p_send.seqnr,
buffer_ptr(&outgoing_packet),
buffer_len(&outgoing_packet));
- DBG(debug("done calc MAC out #%d", send_seqnr));
+ DBG(debug("done calc MAC out #%d", p_send.seqnr));
}
/* encrypt packet and append to output buffer. */
cp = buffer_append_space(&output, buffer_len(&outgoing_packet));
buffer_len(&outgoing_packet));
/* append unencrypted MAC */
if (mac && mac->enabled)
- buffer_append(&output, (char *)macbuf, mac->mac_len);
+ buffer_append(&output, macbuf, mac->mac_len);
#ifdef PACKET_DEBUG
fprintf(stderr, "encrypted: ");
buffer_dump(&output);
#endif
/* increment sequence number for outgoing packets */
- if (++send_seqnr == 0)
- log("outgoing seqnr wraps around");
+ if (++p_send.seqnr == 0)
+ logit("outgoing seqnr wraps around");
+ if (++p_send.packets == 0)
+ if (!(datafellows & SSH_BUG_NOREKEY))
+ fatal("XXX too many packets with same key");
+ p_send.blocks += (packet_length + 4) / block_size;
+ p_send.bytes += packet_length + 4;
buffer_clear(&outgoing_packet);
if (type == SSH2_MSG_NEWKEYS)
set_newkeys(MODE_OUT);
+ else if (type == SSH2_MSG_USERAUTH_SUCCESS && server_side)
+ packet_enable_delayed_compress();
+ return(packet_length);
}
-void
+static int
+packet_send2(void)
+{
+ static int packet_length = 0;
+ static int rekeying = 0;
+ struct packet *p;
+ u_char type, *cp;
+
+ cp = buffer_ptr(&outgoing_packet);
+ type = cp[5];
+
+ /* during rekeying we can only send key exchange messages */
+ if (rekeying) {
+ if (!((type >= SSH2_MSG_TRANSPORT_MIN) &&
+ (type <= SSH2_MSG_TRANSPORT_MAX))) {
+ debug("enqueue packet: %u", type);
+ p = xmalloc(sizeof(*p));
+ p->type = type;
+ memcpy(&p->payload, &outgoing_packet, sizeof(Buffer));
+ buffer_init(&outgoing_packet);
+ TAILQ_INSERT_TAIL(&outgoing, p, next);
+ return(sizeof(Buffer));
+ }
+ }
+
+ /* rekeying starts with sending KEXINIT */
+ if (type == SSH2_MSG_KEXINIT)
+ rekeying = 1;
+
+ packet_length = packet_send2_wrapped();
+
+ /* after a NEWKEYS message we can send the complete queue */
+ if (type == SSH2_MSG_NEWKEYS) {
+ rekeying = 0;
+ while ((p = TAILQ_FIRST(&outgoing))) {
+ type = p->type;
+ debug("dequeue packet: %u", type);
+ buffer_free(&outgoing_packet);
+ memcpy(&outgoing_packet, &p->payload,
+ sizeof(Buffer));
+ TAILQ_REMOVE(&outgoing, p, next);
+ xfree(p);
+ packet_length += packet_send2_wrapped();
+ }
+ }
+ return(packet_length);
+}
+
+int
packet_send(void)
{
+ int packet_len = 0;
if (compat20)
- packet_send2();
+ packet_len = packet_send2();
else
packet_send1();
DBG(debug("packet_send done"));
+ return(packet_len);
}
/*
int
packet_read_seqnr(u_int32_t *seqnr_p)
{
- int type, len;
+ int type, len, ret, ms_remain;
fd_set *setp;
char buf[8192];
+ struct timeval timeout, start, *timeoutp = NULL;
+
DBG(debug("packet_read()"));
- setp = (fd_set *)xmalloc(howmany(connection_in+1, NFDBITS) *
+ setp = (fd_set *)xcalloc(howmany(connection_in+1, NFDBITS),
sizeof(fd_mask));
/* Since we are blocking, ensure that all written packets have been sent. */
sizeof(fd_mask));
FD_SET(connection_in, setp);
+ if (packet_timeout_ms > 0) {
+ ms_remain = packet_timeout_ms;
+ timeoutp = &timeout;
+ }
/* Wait for some data to arrive. */
- while (select(connection_in + 1, setp, NULL, NULL, NULL) == -1 &&
- (errno == EAGAIN || errno == EINTR))
- ;
-
+ for (;;) {
+ if (packet_timeout_ms != -1) {
+ ms_to_timeval(&timeout, ms_remain);
+ gettimeofday(&start, NULL);
+ }
+ if ((ret = select(connection_in + 1, setp, NULL,
+ NULL, timeoutp)) >= 0)
+ break;
+ if (errno != EAGAIN && errno != EINTR &&
+ errno != EWOULDBLOCK)
+ break;
+ if (packet_timeout_ms == -1)
+ continue;
+ ms_subtract_diff(&start, &ms_remain);
+ if (ms_remain <= 0) {
+ ret = 0;
+ break;
+ }
+ }
+ if (ret == 0) {
+ logit("Connection to %.200s timed out while "
+ "waiting to read", get_remote_ipaddr());
+ cleanup_exit(255);
+ }
/* Read data from the socket. */
len = read(connection_in, buf, sizeof(buf));
if (len == 0) {
- log("Connection closed by %.200s", get_remote_ipaddr());
- fatal_cleanup();
+ logit("Connection closed by %.200s", get_remote_ipaddr());
+ cleanup_exit(255);
}
if (len < 0)
fatal("Read from socket failed: %.100s", strerror(errno));
return SSH_MSG_NONE;
/* Get length of incoming packet. */
cp = buffer_ptr(&input);
- len = GET_32BIT(cp);
+ len = get_u32(cp);
if (len < 1 + 2 + 2 || len > 256 * 1024)
- packet_disconnect("Bad packet length %d.", len);
+ packet_disconnect("Bad packet length %u.", len);
padded_len = (len + 8) & ~7;
/* Check if the packet has been entirely received. */
* (C)1998 CORE-SDI, Buenos Aires Argentina
* Ariel Futoransky(futo@core-sdi.com)
*/
- if (!receive_context.plaintext &&
- detect_attack(buffer_ptr(&input), padded_len, NULL) == DEATTACK_DETECTED)
- packet_disconnect("crc32 compensation attack: network attack detected");
+ if (!receive_context.plaintext) {
+ switch (detect_attack(buffer_ptr(&input), padded_len)) {
+ case DEATTACK_DETECTED:
+ packet_disconnect("crc32 compensation attack: "
+ "network attack detected");
+ case DEATTACK_DOS_DETECTED:
+ packet_disconnect("deattack denial of "
+ "service detected");
+ }
+ }
/* Decrypt data to incoming_packet. */
buffer_clear(&incoming_packet);
len, buffer_len(&incoming_packet));
cp = (u_char *)buffer_ptr(&incoming_packet) + len - 4;
- stored_checksum = GET_32BIT(cp);
+ stored_checksum = get_u32(cp);
if (checksum != stored_checksum)
packet_disconnect("Corrupted check bytes on input.");
buffer_consume_end(&incoming_packet, 4);
buffer_append(&incoming_packet, buffer_ptr(&compression_buffer),
buffer_len(&compression_buffer));
}
+ p_read.packets++;
+ p_read.bytes += padded_len + 4;
type = buffer_get_char(&incoming_packet);
+ if (type < SSH_MSG_MIN || type > SSH_MSG_MAX)
+ packet_disconnect("Invalid ssh1 packet type: %d", type);
return type;
}
static u_int packet_length = 0;
u_int padlen, need;
u_char *macbuf, *cp, type;
- int maclen, block_size;
+ u_int maclen, block_size;
Enc *enc = NULL;
Mac *mac = NULL;
Comp *comp = NULL;
+ if (packet_discard)
+ return SSH_MSG_NONE;
+
if (newkeys[MODE_IN] != NULL) {
enc = &newkeys[MODE_IN]->enc;
mac = &newkeys[MODE_IN]->mac;
cipher_crypt(&receive_context, cp, buffer_ptr(&input),
block_size);
cp = buffer_ptr(&incoming_packet);
- packet_length = GET_32BIT(cp);
- if (packet_length < 1 + 4 || packet_length > 256 * 1024) {
+ packet_length = get_u32(cp);
+ if (packet_length < 1 + 4 || packet_length > PACKET_MAX_SIZE) {
+#ifdef PACKET_DEBUG
buffer_dump(&incoming_packet);
- packet_disconnect("Bad packet length %d.", packet_length);
+#endif
+ logit("Bad packet length %u.", packet_length);
+ packet_start_discard(enc, mac, packet_length,
+ PACKET_MAX_SIZE);
+ return SSH_MSG_NONE;
}
- DBG(debug("input: packet len %d", packet_length+4));
+ DBG(debug("input: packet len %u", 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",
+ if (need % block_size != 0) {
+ logit("padding error: need %d block %d mod %d",
need, block_size, need % block_size);
+ packet_start_discard(enc, mac, packet_length,
+ PACKET_MAX_SIZE - block_size);
+ return SSH_MSG_NONE;
+ }
/*
* check if the entire packet has been received and
* decrypt into incoming_packet
* increment sequence number for incoming packet
*/
if (mac && mac->enabled) {
- macbuf = mac_compute(mac, read_seqnr,
+ macbuf = mac_compute(mac, p_read.seqnr,
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", read_seqnr));
+ if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) {
+ logit("Corrupted MAC on input.");
+ if (need > PACKET_MAX_SIZE)
+ fatal("internal error need %d", need);
+ packet_start_discard(enc, mac, packet_length,
+ PACKET_MAX_SIZE - need);
+ return SSH_MSG_NONE;
+ }
+
+ DBG(debug("MAC #%d ok", p_read.seqnr));
buffer_consume(&input, mac->mac_len);
}
+ /* XXX now it's safe to use fatal/packet_disconnect */
if (seqnr_p != NULL)
- *seqnr_p = read_seqnr;
- if (++read_seqnr == 0)
- log("incoming seqnr wraps around");
+ *seqnr_p = p_read.seqnr;
+ if (++p_read.seqnr == 0)
+ logit("incoming seqnr wraps around");
+ if (++p_read.packets == 0)
+ if (!(datafellows & SSH_BUG_NOREKEY))
+ fatal("XXX too many packets with same key");
+ p_read.blocks += (packet_length + 4) / block_size;
+ p_read.bytes += packet_length + 4;
/* get padlen */
cp = buffer_ptr(&incoming_packet);
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)));
+ DBG(debug("input: len after de-compress %d",
+ buffer_len(&incoming_packet)));
}
/*
* get packet type, implies consume.
* return length of payload (without type field)
*/
type = buffer_get_char(&incoming_packet);
+ if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN)
+ packet_disconnect("Invalid ssh2 packet type: %d", type);
if (type == SSH2_MSG_NEWKEYS)
set_newkeys(MODE_IN);
+ else if (type == SSH2_MSG_USERAUTH_SUCCESS && !server_side)
+ packet_enable_delayed_compress();
#ifdef PACKET_DEBUG
fprintf(stderr, "read/plain[%d]:\r\n", type);
buffer_dump(&incoming_packet);
int
packet_read_poll_seqnr(u_int32_t *seqnr_p)
{
- int reason, seqnr;
+ u_int reason, seqnr;
u_char type;
char *msg;
for (;;) {
if (compat20) {
type = packet_read_poll2(seqnr_p);
- if (type)
+ if (type) {
+ keep_alive_timeouts = 0;
DBG(debug("received packet type %d", type));
+ }
switch (type) {
case SSH2_MSG_IGNORE:
+ debug3("Received SSH2_MSG_IGNORE");
break;
case SSH2_MSG_DEBUG:
packet_get_char();
case SSH2_MSG_DISCONNECT:
reason = packet_get_int();
msg = packet_get_string(NULL);
- log("Received disconnect from %s: %d: %.400s", get_remote_ipaddr(),
- reason, msg);
+ logit("Received disconnect from %s: %u: %.400s",
+ get_remote_ipaddr(), reason, msg);
xfree(msg);
- fatal_cleanup();
+ cleanup_exit(255);
break;
case SSH2_MSG_UNIMPLEMENTED:
seqnr = packet_get_int();
- debug("Received SSH2_MSG_UNIMPLEMENTED for %d", seqnr);
+ debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
+ seqnr);
break;
default:
return type;
- break;
}
} else {
type = packet_read_poll1();
break;
case SSH_MSG_DISCONNECT:
msg = packet_get_string(NULL);
- log("Received disconnect from %s: %.400s", get_remote_ipaddr(),
- msg);
- fatal_cleanup();
- xfree(msg);
+ logit("Received disconnect from %s: %.400s",
+ get_remote_ipaddr(), msg);
+ cleanup_exit(255);
break;
default:
if (type)
DBG(debug("received packet type %d", type));
return type;
- break;
}
}
}
void
packet_process_incoming(const char *buf, u_int len)
{
+ if (packet_discard) {
+ keep_alive_timeouts = 0; /* ?? */
+ if (len >= packet_discard)
+ packet_stop_discard();
+ packet_discard -= len;
+ return;
+ }
buffer_append(&input, buf, len);
}
packet_get_char(void)
{
char ch;
+
buffer_get(&incoming_packet, &ch, 1);
return (u_char) ch;
}
}
void *
-packet_get_raw(int *length_ptr)
+packet_get_raw(u_int *length_ptr)
{
- int bytes = buffer_len(&incoming_packet);
+ u_int bytes = buffer_len(&incoming_packet);
+
if (length_ptr != NULL)
*length_ptr = bytes;
return buffer_ptr(&incoming_packet);
return buffer_get_string(&incoming_packet, length_ptr);
}
+void *
+packet_get_string_ptr(u_int *length_ptr)
+{
+ return buffer_get_string_ptr(&incoming_packet, length_ptr);
+}
+
/*
* Sends a diagnostic message from the server to the client. This message
* can be sent at any time (but not while constructing another message). The
char buf[1024];
va_list args;
static int disconnecting = 0;
+
if (disconnecting) /* Guard against recursive invocations. */
fatal("packet_disconnect called recursively.");
disconnecting = 1;
vsnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
+ /* Display the error locally */
+ logit("Disconnecting: %.100s", buf);
+
/* Send the disconnect message to the other side, and wait for it to get sent. */
if (compat20) {
packet_start(SSH2_MSG_DISCONNECT);
/* Close the connection. */
packet_close();
-
- /* Display the error locally and exit. */
- log("Disconnecting: %.100s", buf);
- fatal_cleanup();
+ cleanup_exit(255);
}
/* Checks if there is any buffered output, and tries to write some of the output. */
-void
+int
packet_write_poll(void)
{
- int len = buffer_len(&output);
+ int len = 0;
+ len = buffer_len(&output);
+
if (len > 0) {
len = write(connection_out, buffer_ptr(&output), len);
- if (len <= 0) {
- if (errno == EAGAIN)
- return;
- else
- fatal("Write failed: %.100s", strerror(errno));
+ if (len == -1) {
+ if (errno == EINTR || errno == EAGAIN ||
+ errno == EWOULDBLOCK)
+ return (0);
+ fatal("Write failed: %.100s", strerror(errno));
}
+ if (len == 0)
+ fatal("Write connection closed");
buffer_consume(&output, len);
}
+ return(len);
}
+
/*
* Calls packet_write_poll repeatedly until all pending output data has been
* written.
*/
-void
+int
packet_write_wait(void)
{
fd_set *setp;
+ int ret, ms_remain;
+ struct timeval start, timeout, *timeoutp = NULL;
+ u_int bytes_sent = 0;
- setp = (fd_set *)xmalloc(howmany(connection_out + 1, NFDBITS) *
+ setp = (fd_set *)xcalloc(howmany(connection_out + 1, NFDBITS),
sizeof(fd_mask));
- packet_write_poll();
+ bytes_sent += packet_write_poll();
while (packet_have_data_to_write()) {
memset(setp, 0, howmany(connection_out + 1, NFDBITS) *
sizeof(fd_mask));
FD_SET(connection_out, setp);
- while (select(connection_out + 1, NULL, setp, NULL, NULL) == -1 &&
- (errno == EAGAIN || errno == EINTR))
- ;
- packet_write_poll();
+
+ if (packet_timeout_ms > 0) {
+ ms_remain = packet_timeout_ms;
+ timeoutp = &timeout;
+ }
+ for (;;) {
+ if (packet_timeout_ms != -1) {
+ ms_to_timeval(&timeout, ms_remain);
+ gettimeofday(&start, NULL);
+ }
+ if ((ret = select(connection_out + 1, NULL, setp,
+ NULL, timeoutp)) >= 0)
+ break;
+ if (errno != EAGAIN && errno != EINTR &&
+ errno != EWOULDBLOCK)
+ break;
+ if (packet_timeout_ms == -1)
+ continue;
+ ms_subtract_diff(&start, &ms_remain);
+ if (ms_remain <= 0) {
+ ret = 0;
+ break;
+ }
+ }
+ if (ret == 0) {
+ logit("Connection to %.200s timed out while "
+ "waiting to write", get_remote_ipaddr());
+ cleanup_exit(255);
+ }
+ bytes_sent += packet_write_poll();
}
xfree(setp);
}
return buffer_len(&output) < 128 * 1024;
}
+
+static void
+packet_set_tos(int interactive)
+{
+#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
+ int tos = interactive ? IPTOS_LOWDELAY : IPTOS_THROUGHPUT;
+
+ if (!packet_connection_is_on_socket() ||
+ !packet_connection_is_ipv4())
+ return;
+ if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, &tos,
+ sizeof(tos)) < 0)
+ error("setsockopt IP_TOS %d: %.100s:",
+ tos, strerror(errno));
+#endif
+}
+
/* Informs that the current session is interactive. Sets IP flags for that. */
void
packet_set_interactive(int interactive)
{
static int called = 0;
-#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
- int lowdelay = IPTOS_LOWDELAY;
- int throughput = IPTOS_THROUGHPUT;
-#endif
if (called)
return;
/* Only set socket options if using a socket. */
if (!packet_connection_is_on_socket())
return;
- /*
- * IPTOS_LOWDELAY and IPTOS_THROUGHPUT are IPv4 only
- */
- if (interactive) {
- /*
- * Set IP options for an interactive connection. Use
- * IPTOS_LOWDELAY and TCP_NODELAY.
- */
-#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
- if (packet_connection_is_ipv4()) {
- if (setsockopt(connection_in, IPPROTO_IP, IP_TOS,
- &lowdelay, sizeof(lowdelay)) < 0)
- error("setsockopt IPTOS_LOWDELAY: %.100s",
- strerror(errno));
- }
-#endif
- set_nodelay(connection_in);
- } else if (packet_connection_is_ipv4()) {
- /*
- * Set IP options for a non-interactive connection. Use
- * IPTOS_THROUGHPUT.
- */
-#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
- if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, &throughput,
- sizeof(throughput)) < 0)
- error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno));
-#endif
- }
+ set_nodelay(connection_in);
+ packet_set_tos(interactive);
}
/* Returns true if the current connection is interactive. */
}
int
-packet_set_maxsize(int s)
+packet_set_maxsize(u_int s)
{
static int called = 0;
+
if (called) {
- log("packet_set_maxsize: called twice: old %d new %d",
+ logit("packet_set_maxsize: called twice: old %d new %d",
max_packet_size, s);
return -1;
}
if (s < 4 * 1024 || s > 1024 * 1024) {
- log("packet_set_maxsize: bad size %d", s);
+ logit("packet_set_maxsize: bad size %d", s);
return -1;
}
called = 1;
void
packet_send_ignore(int nbytes)
{
- u_int32_t rand = 0;
+ u_int32_t rnd = 0;
int i;
packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
packet_put_int(nbytes);
for (i = 0; i < nbytes; i++) {
if (i % 4 == 0)
- rand = arc4random();
- packet_put_char(rand & 0xff);
- rand >>= 8;
+ rnd = arc4random();
+ packet_put_char((u_char)rnd & 0xff);
+ rnd >>= 8;
}
}
+
+int rekey_requested = 0;
+void
+packet_request_rekeying(void)
+{
+ rekey_requested = 1;
+}
+
+#define MAX_PACKETS (1U<<31)
+int
+packet_need_rekeying(void)
+{
+ if (datafellows & SSH_BUG_NOREKEY)
+ return 0;
+ if (rekey_requested == 1)
+ {
+ rekey_requested = 0;
+ return 1;
+ }
+ return
+ (p_send.packets > MAX_PACKETS) ||
+ (p_read.packets > MAX_PACKETS) ||
+ (max_blocks_out && (p_send.blocks > max_blocks_out)) ||
+ (max_blocks_in && (p_read.blocks > max_blocks_in));
+}
+
+void
+packet_set_rekey_limit(u_int32_t bytes)
+{
+ rekey_limit = bytes;
+}
+
+void
+packet_set_server(void)
+{
+ server_side = 1;
+}
+
+void
+packet_set_authenticated(void)
+{
+ after_authentication = 1;
+}
+
+int
+packet_authentication_state(void)
+{
+ return(after_authentication);
+}
andersk / gssapi-openssh.git / blobdiff