Put ssh back into the repository
Change-Id: I23324372188fa6ed3f93a32b84365f5df6367590
diff --git a/packet.c b/packet.c
new file mode 100644
index 0000000..ba93417
--- /dev/null
+++ b/packet.c
@@ -0,0 +1,1972 @@
+/* $OpenBSD: packet.c,v 1.173 2011/05/06 21:14:05 djm Exp $ */
+/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ * All rights reserved
+ * This file contains code implementing the packet protocol and communication
+ * with the other side. This same code is used both on client and server side.
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ *
+ * SSH2 packet format added by Markus Friedl.
+ * 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
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#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 "crc32.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"
+#include "canohost.h"
+#include "misc.h"
+#include "ssh.h"
+#include "roaming.h"
+
+#ifdef PACKET_DEBUG
+#define DBG(x) x
+#else
+#define DBG(x)
+#endif
+
+#define PACKET_MAX_SIZE (256 * 1024)
+
+struct packet_state {
+ u_int32_t seqnr;
+ u_int32_t packets;
+ u_int64_t blocks;
+ u_int64_t bytes;
+};
+
+struct packet {
+ TAILQ_ENTRY(packet) next;
+ u_char type;
+ Buffer payload;
+};
+
+struct session_state {
+ /*
+ * This variable contains the file descriptors used for
+ * communicating with the other side. connection_in is used for
+ * reading; connection_out for writing. These can be the same
+ * descriptor, in which case it is assumed to be a socket.
+ */
+ int connection_in;
+ int connection_out;
+
+ /* Protocol flags for the remote side. */
+ u_int remote_protocol_flags;
+
+ /* Encryption context for receiving data. Only used for decryption. */
+ CipherContext receive_context;
+
+ /* Encryption context for sending data. Only used for encryption. */
+ CipherContext send_context;
+
+ /* Buffer for raw input data from the socket. */
+ Buffer input;
+
+ /* Buffer for raw output data going to the socket. */
+ Buffer output;
+
+ /* Buffer for the partial outgoing packet being constructed. */
+ Buffer outgoing_packet;
+
+ /* Buffer for the incoming packet currently being processed. */
+ Buffer incoming_packet;
+
+ /* Scratch buffer for packet compression/decompression. */
+ Buffer compression_buffer;
+ int compression_buffer_ready;
+
+ /*
+ * Flag indicating whether packet compression/decompression is
+ * enabled.
+ */
+ int packet_compression;
+
+ /* default maximum packet size */
+ u_int max_packet_size;
+
+ /* Flag indicating whether this module has been initialized. */
+ int initialized;
+
+ /* Set to true if the connection is interactive. */
+ int interactive_mode;
+
+ /* Set to true if we are the server side. */
+ int server_side;
+
+ /* Set to true if we are authenticated. */
+ int after_authentication;
+
+ int keep_alive_timeouts;
+
+ /* The maximum time that we will wait to send or receive a packet */
+ int packet_timeout_ms;
+
+ /* Session key information for Encryption and MAC */
+ Newkeys *newkeys[MODE_MAX];
+ struct packet_state p_read, p_send;
+
+ u_int64_t max_blocks_in, max_blocks_out;
+ u_int32_t rekey_limit;
+
+ /* Session key for protocol v1 */
+ u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
+ u_int ssh1_keylen;
+
+ /* roundup current message to extra_pad bytes */
+ u_char extra_pad;
+
+ /* XXX discard incoming data after MAC error */
+ u_int packet_discard;
+ Mac *packet_discard_mac;
+
+ /* Used in packet_read_poll2() */
+ u_int packlen;
+
+ /* Used in packet_send2 */
+ int rekeying;
+
+ /* Used in packet_set_interactive */
+ int set_interactive_called;
+
+ /* Used in packet_set_maxsize */
+ int set_maxsize_called;
+
+ TAILQ_HEAD(, packet) outgoing;
+};
+
+static struct session_state *active_state, *backup_state;
+
+static struct session_state *
+alloc_session_state(void)
+{
+ struct session_state *s = xcalloc(1, sizeof(*s));
+
+ s->connection_in = -1;
+ s->connection_out = -1;
+ s->max_packet_size = 32768;
+ s->packet_timeout_ms = -1;
+ return s;
+}
+
+/*
+ * Sets the descriptors used for communication. Disables encryption until
+ * packet_set_encryption_key is called.
+ */
+void
+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'");
+ if (active_state == NULL)
+ active_state = alloc_session_state();
+ active_state->connection_in = fd_in;
+ active_state->connection_out = fd_out;
+ cipher_init(&active_state->send_context, none, (const u_char *)"",
+ 0, NULL, 0, CIPHER_ENCRYPT);
+ cipher_init(&active_state->receive_context, none, (const u_char *)"",
+ 0, NULL, 0, CIPHER_DECRYPT);
+ active_state->newkeys[MODE_IN] = active_state->newkeys[MODE_OUT] = NULL;
+ if (!active_state->initialized) {
+ active_state->initialized = 1;
+ buffer_init(&active_state->input);
+ buffer_init(&active_state->output);
+ buffer_init(&active_state->outgoing_packet);
+ buffer_init(&active_state->incoming_packet);
+ TAILQ_INIT(&active_state->outgoing);
+ active_state->p_send.packets = active_state->p_read.packets = 0;
+ }
+}
+
+void
+packet_set_timeout(int timeout, int count)
+{
+ if (timeout == 0 || count == 0) {
+ active_state->packet_timeout_ms = -1;
+ return;
+ }
+ if ((INT_MAX / 1000) / count < timeout)
+ active_state->packet_timeout_ms = INT_MAX;
+ else
+ active_state->packet_timeout_ms = timeout * count * 1000;
+}
+
+static void
+packet_stop_discard(void)
+{
+ if (active_state->packet_discard_mac) {
+ char buf[1024];
+
+ memset(buf, 'a', sizeof(buf));
+ while (buffer_len(&active_state->incoming_packet) <
+ PACKET_MAX_SIZE)
+ buffer_append(&active_state->incoming_packet, buf,
+ sizeof(buf));
+ (void) mac_compute(active_state->packet_discard_mac,
+ active_state->p_read.seqnr,
+ buffer_ptr(&active_state->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)
+ active_state->packet_discard_mac = mac;
+ if (buffer_len(&active_state->input) >= discard)
+ packet_stop_discard();
+ active_state->packet_discard = discard -
+ buffer_len(&active_state->input);
+}
+
+/* Returns 1 if remote host is connected via socket, 0 if not. */
+
+int
+packet_connection_is_on_socket(void)
+{
+ struct sockaddr_storage from, to;
+ socklen_t fromlen, tolen;
+
+ /* filedescriptors in and out are the same, so it's a socket */
+ if (active_state->connection_in == active_state->connection_out)
+ return 1;
+ fromlen = sizeof(from);
+ memset(&from, 0, sizeof(from));
+ if (getpeername(active_state->connection_in, (struct sockaddr *)&from,
+ &fromlen) < 0)
+ return 0;
+ tolen = sizeof(to);
+ memset(&to, 0, sizeof(to));
+ if (getpeername(active_state->connection_out, (struct sockaddr *)&to,
+ &tolen) < 0)
+ return 0;
+ if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
+ return 0;
+ if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
+ return 0;
+ return 1;
+}
+
+/*
+ * Exports an IV from the CipherContext required to export the key
+ * state back from the unprivileged child to the privileged parent
+ * process.
+ */
+
+void
+packet_get_keyiv(int mode, u_char *iv, u_int len)
+{
+ CipherContext *cc;
+
+ if (mode == MODE_OUT)
+ cc = &active_state->send_context;
+ else
+ cc = &active_state->receive_context;
+
+ cipher_get_keyiv(cc, iv, len);
+}
+
+int
+packet_get_keycontext(int mode, u_char *dat)
+{
+ CipherContext *cc;
+
+ if (mode == MODE_OUT)
+ cc = &active_state->send_context;
+ else
+ cc = &active_state->receive_context;
+
+ return (cipher_get_keycontext(cc, dat));
+}
+
+void
+packet_set_keycontext(int mode, u_char *dat)
+{
+ CipherContext *cc;
+
+ if (mode == MODE_OUT)
+ cc = &active_state->send_context;
+ else
+ cc = &active_state->receive_context;
+
+ cipher_set_keycontext(cc, dat);
+}
+
+int
+packet_get_keyiv_len(int mode)
+{
+ CipherContext *cc;
+
+ if (mode == MODE_OUT)
+ cc = &active_state->send_context;
+ else
+ cc = &active_state->receive_context;
+
+ return (cipher_get_keyiv_len(cc));
+}
+
+void
+packet_set_iv(int mode, u_char *dat)
+{
+ CipherContext *cc;
+
+ if (mode == MODE_OUT)
+ cc = &active_state->send_context;
+ else
+ cc = &active_state->receive_context;
+
+ cipher_set_keyiv(cc, dat);
+}
+
+int
+packet_get_ssh1_cipher(void)
+{
+ return (cipher_get_number(active_state->receive_context.cipher));
+}
+
+void
+packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks,
+ u_int32_t *packets, u_int64_t *bytes)
+{
+ struct packet_state *state;
+
+ state = (mode == MODE_IN) ?
+ &active_state->p_read : &active_state->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_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets,
+ u_int64_t bytes)
+{
+ struct packet_state *state;
+
+ state = (mode == MODE_IN) ?
+ &active_state->p_read : &active_state->p_send;
+ state->seqnr = seqnr;
+ state->blocks = blocks;
+ state->packets = packets;
+ state->bytes = bytes;
+}
+
+static int
+packet_connection_af(void)
+{
+ struct sockaddr_storage to;
+ socklen_t tolen = sizeof(to);
+
+ memset(&to, 0, sizeof(to));
+ if (getsockname(active_state->connection_out, (struct sockaddr *)&to,
+ &tolen) < 0)
+ return 0;
+ if (to.ss_family == AF_INET)
+ return 1;
+#ifdef IPV4_IN_IPV6
+ if (to.ss_family == AF_INET6 &&
+ IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
+ return AF_INET;
+#endif
+ return to.ss_family;
+}
+
+/* Sets the connection into non-blocking mode. */
+
+void
+packet_set_nonblocking(void)
+{
+ /* Set the socket into non-blocking mode. */
+ set_nonblock(active_state->connection_in);
+
+ if (active_state->connection_out != active_state->connection_in)
+ set_nonblock(active_state->connection_out);
+}
+
+/* Returns the socket used for reading. */
+
+int
+packet_get_connection_in(void)
+{
+ return active_state->connection_in;
+}
+
+/* Returns the descriptor used for writing. */
+
+int
+packet_get_connection_out(void)
+{
+ return active_state->connection_out;
+}
+
+/* Closes the connection and clears and frees internal data structures. */
+
+void
+packet_close(void)
+{
+ if (!active_state->initialized)
+ return;
+ active_state->initialized = 0;
+ if (active_state->connection_in == active_state->connection_out) {
+ shutdown(active_state->connection_out, SHUT_RDWR);
+ close(active_state->connection_out);
+ } else {
+ close(active_state->connection_in);
+ close(active_state->connection_out);
+ }
+ buffer_free(&active_state->input);
+ buffer_free(&active_state->output);
+ buffer_free(&active_state->outgoing_packet);
+ buffer_free(&active_state->incoming_packet);
+ if (active_state->compression_buffer_ready) {
+ buffer_free(&active_state->compression_buffer);
+ buffer_compress_uninit();
+ }
+ cipher_cleanup(&active_state->send_context);
+ cipher_cleanup(&active_state->receive_context);
+}
+
+/* Sets remote side protocol flags. */
+
+void
+packet_set_protocol_flags(u_int protocol_flags)
+{
+ active_state->remote_protocol_flags = protocol_flags;
+}
+
+/* Returns the remote protocol flags set earlier by the above function. */
+
+u_int
+packet_get_protocol_flags(void)
+{
+ return active_state->remote_protocol_flags;
+}
+
+/*
+ * Starts packet compression from the next packet on in both directions.
+ * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
+ */
+
+static void
+packet_init_compression(void)
+{
+ if (active_state->compression_buffer_ready == 1)
+ return;
+ active_state->compression_buffer_ready = 1;
+ buffer_init(&active_state->compression_buffer);
+}
+
+void
+packet_start_compression(int level)
+{
+ if (active_state->packet_compression && !compat20)
+ fatal("Compression already enabled.");
+ active_state->packet_compression = 1;
+ packet_init_compression();
+ buffer_compress_init_send(level);
+ buffer_compress_init_recv();
+}
+
+/*
+ * 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)
+{
+ Cipher *cipher = cipher_by_number(number);
+
+ if (cipher == NULL)
+ fatal("packet_set_encryption_key: unknown cipher number %d", number);
+ if (keylen < 20)
+ fatal("packet_set_encryption_key: keylen too small: %d", keylen);
+ if (keylen > SSH_SESSION_KEY_LENGTH)
+ fatal("packet_set_encryption_key: keylen too big: %d", keylen);
+ memcpy(active_state->ssh1_key, key, keylen);
+ active_state->ssh1_keylen = keylen;
+ cipher_init(&active_state->send_context, cipher, key, keylen, NULL,
+ 0, CIPHER_ENCRYPT);
+ cipher_init(&active_state->receive_context, cipher, key, keylen, NULL,
+ 0, CIPHER_DECRYPT);
+}
+
+u_int
+packet_get_encryption_key(u_char *key)
+{
+ if (key == NULL)
+ return (active_state->ssh1_keylen);
+ memcpy(key, active_state->ssh1_key, active_state->ssh1_keylen);
+ return (active_state->ssh1_keylen);
+}
+
+/* Start constructing a packet to send. */
+void
+packet_start(u_char type)
+{
+ u_char buf[9];
+ int len;
+
+ DBG(debug("packet_start[%d]", type));
+ len = compat20 ? 6 : 9;
+ memset(buf, 0, len - 1);
+ buf[len - 1] = type;
+ buffer_clear(&active_state->outgoing_packet);
+ buffer_append(&active_state->outgoing_packet, buf, len);
+}
+
+/* Append payload. */
+void
+packet_put_char(int value)
+{
+ char ch = value;
+
+ buffer_append(&active_state->outgoing_packet, &ch, 1);
+}
+
+void
+packet_put_int(u_int value)
+{
+ buffer_put_int(&active_state->outgoing_packet, value);
+}
+
+void
+packet_put_int64(u_int64_t value)
+{
+ buffer_put_int64(&active_state->outgoing_packet, value);
+}
+
+void
+packet_put_string(const void *buf, u_int len)
+{
+ buffer_put_string(&active_state->outgoing_packet, buf, len);
+}
+
+void
+packet_put_cstring(const char *str)
+{
+ buffer_put_cstring(&active_state->outgoing_packet, str);
+}
+
+void
+packet_put_raw(const void *buf, u_int len)
+{
+ buffer_append(&active_state->outgoing_packet, buf, len);
+}
+
+void
+packet_put_bignum(BIGNUM * value)
+{
+ buffer_put_bignum(&active_state->outgoing_packet, value);
+}
+
+void
+packet_put_bignum2(BIGNUM * value)
+{
+ buffer_put_bignum2(&active_state->outgoing_packet, value);
+}
+
+#ifdef OPENSSL_HAS_ECC
+void
+packet_put_ecpoint(const EC_GROUP *curve, const EC_POINT *point)
+{
+ buffer_put_ecpoint(&active_state->outgoing_packet, curve, point);
+}
+#endif
+
+/*
+ * Finalizes and sends the packet. If the encryption key has been set,
+ * encrypts the packet before sending.
+ */
+
+static void
+packet_send1(void)
+{
+ u_char buf[8], *cp;
+ int i, padding, len;
+ u_int checksum;
+ u_int32_t rnd = 0;
+
+ /*
+ * If using packet compression, compress the payload of the outgoing
+ * packet.
+ */
+ if (active_state->packet_compression) {
+ buffer_clear(&active_state->compression_buffer);
+ /* Skip padding. */
+ buffer_consume(&active_state->outgoing_packet, 8);
+ /* padding */
+ buffer_append(&active_state->compression_buffer,
+ "\0\0\0\0\0\0\0\0", 8);
+ buffer_compress(&active_state->outgoing_packet,
+ &active_state->compression_buffer);
+ buffer_clear(&active_state->outgoing_packet);
+ buffer_append(&active_state->outgoing_packet,
+ buffer_ptr(&active_state->compression_buffer),
+ buffer_len(&active_state->compression_buffer));
+ }
+ /* Compute packet length without padding (add checksum, remove padding). */
+ len = buffer_len(&active_state->outgoing_packet) + 4 - 8;
+
+ /* Insert padding. Initialized to zero in packet_start1() */
+ padding = 8 - len % 8;
+ if (!active_state->send_context.plaintext) {
+ cp = buffer_ptr(&active_state->outgoing_packet);
+ for (i = 0; i < padding; i++) {
+ if (i % 4 == 0)
+ rnd = arc4random();
+ cp[7 - i] = rnd & 0xff;
+ rnd >>= 8;
+ }
+ }
+ buffer_consume(&active_state->outgoing_packet, 8 - padding);
+
+ /* Add check bytes. */
+ checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet),
+ buffer_len(&active_state->outgoing_packet));
+ put_u32(buf, checksum);
+ buffer_append(&active_state->outgoing_packet, buf, 4);
+
+#ifdef PACKET_DEBUG
+ fprintf(stderr, "packet_send plain: ");
+ buffer_dump(&active_state->outgoing_packet);
+#endif
+
+ /* Append to output. */
+ put_u32(buf, len);
+ buffer_append(&active_state->output, buf, 4);
+ cp = buffer_append_space(&active_state->output,
+ buffer_len(&active_state->outgoing_packet));
+ cipher_crypt(&active_state->send_context, cp,
+ buffer_ptr(&active_state->outgoing_packet),
+ buffer_len(&active_state->outgoing_packet));
+
+#ifdef PACKET_DEBUG
+ fprintf(stderr, "encrypted: ");
+ buffer_dump(&active_state->output);
+#endif
+ active_state->p_send.packets++;
+ active_state->p_send.bytes += len +
+ buffer_len(&active_state->outgoing_packet);
+ buffer_clear(&active_state->outgoing_packet);
+
+ /*
+ * 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.
+ */
+}
+
+void
+set_newkeys(int mode)
+{
+ Enc *enc;
+ Mac *mac;
+ Comp *comp;
+ CipherContext *cc;
+ u_int64_t *max_blocks;
+ int crypt_type;
+
+ debug2("set_newkeys: mode %d", mode);
+
+ if (mode == MODE_OUT) {
+ cc = &active_state->send_context;
+ crypt_type = CIPHER_ENCRYPT;
+ active_state->p_send.packets = active_state->p_send.blocks = 0;
+ max_blocks = &active_state->max_blocks_out;
+ } else {
+ cc = &active_state->receive_context;
+ crypt_type = CIPHER_DECRYPT;
+ active_state->p_read.packets = active_state->p_read.blocks = 0;
+ max_blocks = &active_state->max_blocks_in;
+ }
+ if (active_state->newkeys[mode] != NULL) {
+ debug("set_newkeys: rekeying");
+ cipher_cleanup(cc);
+ enc = &active_state->newkeys[mode]->enc;
+ mac = &active_state->newkeys[mode]->mac;
+ comp = &active_state->newkeys[mode]->comp;
+ mac_clear(mac);
+ xfree(enc->name);
+ xfree(enc->iv);
+ xfree(enc->key);
+ xfree(mac->name);
+ xfree(mac->key);
+ xfree(comp->name);
+ xfree(active_state->newkeys[mode]);
+ }
+ active_state->newkeys[mode] = kex_get_newkeys(mode);
+ if (active_state->newkeys[mode] == NULL)
+ fatal("newkeys: no keys for mode %d", mode);
+ enc = &active_state->newkeys[mode]->enc;
+ mac = &active_state->newkeys[mode]->mac;
+ comp = &active_state->newkeys[mode]->comp;
+ 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, crypt_type);
+ /* Deleting the keys does not gain extra security */
+ /* memset(enc->iv, 0, enc->block_size);
+ memset(enc->key, 0, enc->key_len);
+ memset(mac->key, 0, mac->key_len); */
+ if ((comp->type == COMP_ZLIB ||
+ (comp->type == COMP_DELAYED &&
+ active_state->after_authentication)) && comp->enabled == 0) {
+ packet_init_compression();
+ if (mode == MODE_OUT)
+ buffer_compress_init_send(6);
+ else
+ 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 (active_state->rekey_limit)
+ *max_blocks = MIN(*max_blocks,
+ active_state->rekey_limit / enc->block_size);
+}
+
+/*
+ * 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_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.
+ */
+ active_state->after_authentication = 1;
+ for (mode = 0; mode < MODE_MAX; mode++) {
+ /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
+ if (active_state->newkeys[mode] == NULL)
+ continue;
+ comp = &active_state->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 void
+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 rnd = 0;
+ Enc *enc = NULL;
+ Mac *mac = NULL;
+ Comp *comp = NULL;
+ int block_size;
+
+ if (active_state->newkeys[MODE_OUT] != NULL) {
+ enc = &active_state->newkeys[MODE_OUT]->enc;
+ mac = &active_state->newkeys[MODE_OUT]->mac;
+ comp = &active_state->newkeys[MODE_OUT]->comp;
+ }
+ block_size = enc ? enc->block_size : 8;
+
+ cp = buffer_ptr(&active_state->outgoing_packet);
+ type = cp[5];
+
+#ifdef PACKET_DEBUG
+ fprintf(stderr, "plain: ");
+ buffer_dump(&active_state->outgoing_packet);
+#endif
+
+ if (comp && comp->enabled) {
+ len = buffer_len(&active_state->outgoing_packet);
+ /* skip header, compress only payload */
+ buffer_consume(&active_state->outgoing_packet, 5);
+ buffer_clear(&active_state->compression_buffer);
+ buffer_compress(&active_state->outgoing_packet,
+ &active_state->compression_buffer);
+ buffer_clear(&active_state->outgoing_packet);
+ buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5);
+ buffer_append(&active_state->outgoing_packet,
+ buffer_ptr(&active_state->compression_buffer),
+ buffer_len(&active_state->compression_buffer));
+ DBG(debug("compression: raw %d compressed %d", len,
+ buffer_len(&active_state->outgoing_packet)));
+ }
+
+ /* sizeof (packet_len + pad_len + payload) */
+ len = buffer_len(&active_state->outgoing_packet);
+
+ /*
+ * calc size of padding, alloc space, get random data,
+ * minimum padding is 4 bytes
+ */
+ padlen = block_size - (len % block_size);
+ if (padlen < 4)
+ padlen += block_size;
+ if (active_state->extra_pad) {
+ /* will wrap if extra_pad+padlen > 255 */
+ active_state->extra_pad =
+ roundup(active_state->extra_pad, block_size);
+ pad = active_state->extra_pad -
+ ((len + padlen) % active_state->extra_pad);
+ debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
+ pad, len, padlen, active_state->extra_pad);
+ padlen += pad;
+ active_state->extra_pad = 0;
+ }
+ cp = buffer_append_space(&active_state->outgoing_packet, padlen);
+ if (enc && !active_state->send_context.plaintext) {
+ /* random padding */
+ for (i = 0; i < padlen; i++) {
+ if (i % 4 == 0)
+ rnd = arc4random();
+ cp[i] = rnd & 0xff;
+ rnd >>= 8;
+ }
+ } else {
+ /* clear padding */
+ memset(cp, 0, padlen);
+ }
+ /* packet_length includes payload, padding and padding length field */
+ packet_length = buffer_len(&active_state->outgoing_packet) - 4;
+ cp = buffer_ptr(&active_state->outgoing_packet);
+ 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, active_state->p_send.seqnr,
+ buffer_ptr(&active_state->outgoing_packet),
+ buffer_len(&active_state->outgoing_packet));
+ DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr));
+ }
+ /* encrypt packet and append to output buffer. */
+ cp = buffer_append_space(&active_state->output,
+ buffer_len(&active_state->outgoing_packet));
+ cipher_crypt(&active_state->send_context, cp,
+ buffer_ptr(&active_state->outgoing_packet),
+ buffer_len(&active_state->outgoing_packet));
+ /* append unencrypted MAC */
+ if (mac && mac->enabled)
+ buffer_append(&active_state->output, macbuf, mac->mac_len);
+#ifdef PACKET_DEBUG
+ fprintf(stderr, "encrypted: ");
+ buffer_dump(&active_state->output);
+#endif
+ /* increment sequence number for outgoing packets */
+ if (++active_state->p_send.seqnr == 0)
+ logit("outgoing seqnr wraps around");
+ if (++active_state->p_send.packets == 0)
+ if (!(datafellows & SSH_BUG_NOREKEY))
+ fatal("XXX too many packets with same key");
+ active_state->p_send.blocks += (packet_length + 4) / block_size;
+ active_state->p_send.bytes += packet_length + 4;
+ buffer_clear(&active_state->outgoing_packet);
+
+ if (type == SSH2_MSG_NEWKEYS)
+ set_newkeys(MODE_OUT);
+ else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side)
+ packet_enable_delayed_compress();
+}
+
+static void
+packet_send2(void)
+{
+ struct packet *p;
+ u_char type, *cp;
+
+ cp = buffer_ptr(&active_state->outgoing_packet);
+ type = cp[5];
+
+ /* during rekeying we can only send key exchange messages */
+ if (active_state->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, &active_state->outgoing_packet,
+ sizeof(Buffer));
+ buffer_init(&active_state->outgoing_packet);
+ TAILQ_INSERT_TAIL(&active_state->outgoing, p, next);
+ return;
+ }
+ }
+
+ /* rekeying starts with sending KEXINIT */
+ if (type == SSH2_MSG_KEXINIT)
+ active_state->rekeying = 1;
+
+ packet_send2_wrapped();
+
+ /* after a NEWKEYS message we can send the complete queue */
+ if (type == SSH2_MSG_NEWKEYS) {
+ active_state->rekeying = 0;
+ while ((p = TAILQ_FIRST(&active_state->outgoing))) {
+ type = p->type;
+ debug("dequeue packet: %u", type);
+ buffer_free(&active_state->outgoing_packet);
+ memcpy(&active_state->outgoing_packet, &p->payload,
+ sizeof(Buffer));
+ TAILQ_REMOVE(&active_state->outgoing, p, next);
+ xfree(p);
+ packet_send2_wrapped();
+ }
+ }
+}
+
+void
+packet_send(void)
+{
+ if (compat20)
+ packet_send2();
+ else
+ packet_send1();
+ DBG(debug("packet_send done"));
+}
+
+/*
+ * Waits until a packet has been received, and returns its type. Note that
+ * no other data is processed until this returns, so this function should not
+ * be used during the interactive session.
+ */
+
+int
+packet_read_seqnr(u_int32_t *seqnr_p)
+{
+ int type, len, ret, ms_remain, cont;
+ fd_set *setp;
+ char buf[8192];
+ struct timeval timeout, start, *timeoutp = NULL;
+
+ DBG(debug("packet_read()"));
+
+ setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1,
+ NFDBITS), sizeof(fd_mask));
+
+ /* Since we are blocking, ensure that all written packets have been sent. */
+ packet_write_wait();
+
+ /* Stay in the loop until we have received a complete packet. */
+ for (;;) {
+ /* Try to read a packet from the buffer. */
+ 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_check_eom();
+ /* If we got a packet, return it. */
+ if (type != SSH_MSG_NONE) {
+ xfree(setp);
+ return type;
+ }
+ /*
+ * Otherwise, wait for some data to arrive, add it to the
+ * buffer, and try again.
+ */
+ memset(setp, 0, howmany(active_state->connection_in + 1,
+ NFDBITS) * sizeof(fd_mask));
+ FD_SET(active_state->connection_in, setp);
+
+ if (active_state->packet_timeout_ms > 0) {
+ ms_remain = active_state->packet_timeout_ms;
+ timeoutp = &timeout;
+ }
+ /* Wait for some data to arrive. */
+ for (;;) {
+ if (active_state->packet_timeout_ms != -1) {
+ ms_to_timeval(&timeout, ms_remain);
+ gettimeofday(&start, NULL);
+ }
+ if ((ret = select(active_state->connection_in + 1, setp,
+ NULL, NULL, timeoutp)) >= 0)
+ break;
+ if (errno != EAGAIN && errno != EINTR &&
+ errno != EWOULDBLOCK)
+ break;
+ if (active_state->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. */
+ do {
+ cont = 0;
+ len = roaming_read(active_state->connection_in, buf,
+ sizeof(buf), &cont);
+ } while (len == 0 && cont);
+ if (len == 0) {
+ logit("Connection closed by %.200s", get_remote_ipaddr());
+ cleanup_exit(255);
+ }
+ if (len < 0)
+ fatal("Read from socket failed: %.100s", strerror(errno));
+ /* Append it to the buffer. */
+ packet_process_incoming(buf, len);
+ }
+ /* 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 expected_type)
+{
+ int type;
+
+ type = packet_read();
+ if (type != expected_type)
+ packet_disconnect("Protocol error: expected packet type %d, got %d",
+ expected_type, type);
+}
+
+/* Checks if a full packet is available in the data received so far via
+ * packet_process_incoming. If so, reads the packet; otherwise returns
+ * SSH_MSG_NONE. This does not wait for data from the connection.
+ *
+ * SSH_MSG_DISCONNECT is handled specially here. Also,
+ * SSH_MSG_IGNORE messages are skipped by this function and are never returned
+ * to higher levels.
+ */
+
+static int
+packet_read_poll1(void)
+{
+ u_int len, padded_len;
+ u_char *cp, type;
+ u_int checksum, stored_checksum;
+
+ /* Check if input size is less than minimum packet size. */
+ if (buffer_len(&active_state->input) < 4 + 8)
+ return SSH_MSG_NONE;
+ /* Get length of incoming packet. */
+ cp = buffer_ptr(&active_state->input);
+ len = get_u32(cp);
+ if (len < 1 + 2 + 2 || len > 256 * 1024)
+ packet_disconnect("Bad packet length %u.", len);
+ padded_len = (len + 8) & ~7;
+
+ /* Check if the packet has been entirely received. */
+ if (buffer_len(&active_state->input) < 4 + padded_len)
+ return SSH_MSG_NONE;
+
+ /* The entire packet is in buffer. */
+
+ /* Consume packet length. */
+ buffer_consume(&active_state->input, 4);
+
+ /*
+ * Cryptographic attack detector for ssh
+ * (C)1998 CORE-SDI, Buenos Aires Argentina
+ * Ariel Futoransky(futo@core-sdi.com)
+ */
+ if (!active_state->receive_context.plaintext) {
+ switch (detect_attack(buffer_ptr(&active_state->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(&active_state->incoming_packet);
+ cp = buffer_append_space(&active_state->incoming_packet, padded_len);
+ cipher_crypt(&active_state->receive_context, cp,
+ buffer_ptr(&active_state->input), padded_len);
+
+ buffer_consume(&active_state->input, padded_len);
+
+#ifdef PACKET_DEBUG
+ fprintf(stderr, "read_poll plain: ");
+ buffer_dump(&active_state->incoming_packet);
+#endif
+
+ /* Compute packet checksum. */
+ checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet),
+ buffer_len(&active_state->incoming_packet) - 4);
+
+ /* Skip padding. */
+ buffer_consume(&active_state->incoming_packet, 8 - len % 8);
+
+ /* Test check bytes. */
+ if (len != buffer_len(&active_state->incoming_packet))
+ packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
+ len, buffer_len(&active_state->incoming_packet));
+
+ cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4;
+ stored_checksum = get_u32(cp);
+ if (checksum != stored_checksum)
+ packet_disconnect("Corrupted check bytes on input.");
+ buffer_consume_end(&active_state->incoming_packet, 4);
+
+ if (active_state->packet_compression) {
+ buffer_clear(&active_state->compression_buffer);
+ buffer_uncompress(&active_state->incoming_packet,
+ &active_state->compression_buffer);
+ buffer_clear(&active_state->incoming_packet);
+ buffer_append(&active_state->incoming_packet,
+ buffer_ptr(&active_state->compression_buffer),
+ buffer_len(&active_state->compression_buffer));
+ }
+ active_state->p_read.packets++;
+ active_state->p_read.bytes += padded_len + 4;
+ type = buffer_get_char(&active_state->incoming_packet);
+ if (type < SSH_MSG_MIN || type > SSH_MSG_MAX)
+ packet_disconnect("Invalid ssh1 packet type: %d", type);
+ return type;
+}
+
+static int
+packet_read_poll2(u_int32_t *seqnr_p)
+{
+ u_int padlen, need;
+ u_char *macbuf, *cp, type;
+ u_int maclen, block_size;
+ Enc *enc = NULL;
+ Mac *mac = NULL;
+ Comp *comp = NULL;
+
+ if (active_state->packet_discard)
+ return SSH_MSG_NONE;
+
+ if (active_state->newkeys[MODE_IN] != NULL) {
+ enc = &active_state->newkeys[MODE_IN]->enc;
+ mac = &active_state->newkeys[MODE_IN]->mac;
+ comp = &active_state->newkeys[MODE_IN]->comp;
+ }
+ maclen = mac && mac->enabled ? mac->mac_len : 0;
+ block_size = enc ? enc->block_size : 8;
+
+ if (active_state->packlen == 0) {
+ /*
+ * check if input size is less than the cipher block size,
+ * decrypt first block and extract length of incoming packet
+ */
+ if (buffer_len(&active_state->input) < block_size)
+ return SSH_MSG_NONE;
+ buffer_clear(&active_state->incoming_packet);
+ cp = buffer_append_space(&active_state->incoming_packet,
+ block_size);
+ cipher_crypt(&active_state->receive_context, cp,
+ buffer_ptr(&active_state->input), block_size);
+ cp = buffer_ptr(&active_state->incoming_packet);
+ active_state->packlen = get_u32(cp);
+ if (active_state->packlen < 1 + 4 ||
+ active_state->packlen > PACKET_MAX_SIZE) {
+#ifdef PACKET_DEBUG
+ buffer_dump(&active_state->incoming_packet);
+#endif
+ logit("Bad packet length %u.", active_state->packlen);
+ packet_start_discard(enc, mac, active_state->packlen,
+ PACKET_MAX_SIZE);
+ return SSH_MSG_NONE;
+ }
+ DBG(debug("input: packet len %u", active_state->packlen+4));
+ buffer_consume(&active_state->input, block_size);
+ }
+ /* we have a partial packet of block_size bytes */
+ need = 4 + active_state->packlen - block_size;
+ DBG(debug("partial packet %d, need %d, maclen %d", block_size,
+ need, maclen));
+ 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, active_state->packlen,
+ PACKET_MAX_SIZE - block_size);
+ return SSH_MSG_NONE;
+ }
+ /*
+ * check if the entire packet has been received and
+ * decrypt into incoming_packet
+ */
+ if (buffer_len(&active_state->input) < need + maclen)
+ return SSH_MSG_NONE;
+#ifdef PACKET_DEBUG
+ fprintf(stderr, "read_poll enc/full: ");
+ buffer_dump(&active_state->input);
+#endif
+ cp = buffer_append_space(&active_state->incoming_packet, need);
+ cipher_crypt(&active_state->receive_context, cp,
+ buffer_ptr(&active_state->input), need);
+ buffer_consume(&active_state->input, need);
+ /*
+ * compute MAC over seqnr and packet,
+ * increment sequence number for incoming packet
+ */
+ if (mac && mac->enabled) {
+ macbuf = mac_compute(mac, active_state->p_read.seqnr,
+ buffer_ptr(&active_state->incoming_packet),
+ buffer_len(&active_state->incoming_packet));
+ if (timingsafe_bcmp(macbuf, buffer_ptr(&active_state->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, active_state->packlen,
+ PACKET_MAX_SIZE - need);
+ return SSH_MSG_NONE;
+ }
+
+ DBG(debug("MAC #%d ok", active_state->p_read.seqnr));
+ buffer_consume(&active_state->input, mac->mac_len);
+ }
+ /* XXX now it's safe to use fatal/packet_disconnect */
+ if (seqnr_p != NULL)
+ *seqnr_p = active_state->p_read.seqnr;
+ if (++active_state->p_read.seqnr == 0)
+ logit("incoming seqnr wraps around");
+ if (++active_state->p_read.packets == 0)
+ if (!(datafellows & SSH_BUG_NOREKEY))
+ fatal("XXX too many packets with same key");
+ active_state->p_read.blocks += (active_state->packlen + 4) / block_size;
+ active_state->p_read.bytes += active_state->packlen + 4;
+
+ /* get padlen */
+ cp = buffer_ptr(&active_state->incoming_packet);
+ padlen = cp[4];
+ DBG(debug("input: padlen %d", padlen));
+ if (padlen < 4)
+ packet_disconnect("Corrupted padlen %d on input.", padlen);
+
+ /* skip packet size + padlen, discard padding */
+ buffer_consume(&active_state->incoming_packet, 4 + 1);
+ buffer_consume_end(&active_state->incoming_packet, padlen);
+
+ DBG(debug("input: len before de-compress %d",
+ buffer_len(&active_state->incoming_packet)));
+ if (comp && comp->enabled) {
+ buffer_clear(&active_state->compression_buffer);
+ buffer_uncompress(&active_state->incoming_packet,
+ &active_state->compression_buffer);
+ buffer_clear(&active_state->incoming_packet);
+ buffer_append(&active_state->incoming_packet,
+ buffer_ptr(&active_state->compression_buffer),
+ buffer_len(&active_state->compression_buffer));
+ DBG(debug("input: len after de-compress %d",
+ buffer_len(&active_state->incoming_packet)));
+ }
+ /*
+ * get packet type, implies consume.
+ * return length of payload (without type field)
+ */
+ type = buffer_get_char(&active_state->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 &&
+ !active_state->server_side)
+ packet_enable_delayed_compress();
+#ifdef PACKET_DEBUG
+ fprintf(stderr, "read/plain[%d]:\r\n", type);
+ buffer_dump(&active_state->incoming_packet);
+#endif
+ /* reset for next packet */
+ active_state->packlen = 0;
+ return type;
+}
+
+int
+packet_read_poll_seqnr(u_int32_t *seqnr_p)
+{
+ u_int reason, seqnr;
+ u_char type;
+ char *msg;
+
+ for (;;) {
+ if (compat20) {
+ type = packet_read_poll2(seqnr_p);
+ if (type) {
+ active_state->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();
+ msg = packet_get_string(NULL);
+ debug("Remote: %.900s", msg);
+ xfree(msg);
+ msg = packet_get_string(NULL);
+ xfree(msg);
+ break;
+ case SSH2_MSG_DISCONNECT:
+ reason = packet_get_int();
+ msg = packet_get_string(NULL);
+ logit("Received disconnect from %s: %u: %.400s",
+ get_remote_ipaddr(), reason, msg);
+ xfree(msg);
+ cleanup_exit(255);
+ break;
+ case SSH2_MSG_UNIMPLEMENTED:
+ seqnr = packet_get_int();
+ debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
+ seqnr);
+ break;
+ default:
+ return type;
+ }
+ } else {
+ type = packet_read_poll1();
+ switch (type) {
+ case SSH_MSG_IGNORE:
+ break;
+ case SSH_MSG_DEBUG:
+ msg = packet_get_string(NULL);
+ debug("Remote: %.900s", msg);
+ xfree(msg);
+ break;
+ case SSH_MSG_DISCONNECT:
+ msg = packet_get_string(NULL);
+ 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;
+ }
+ }
+ }
+}
+
+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.
+ */
+
+void
+packet_process_incoming(const char *buf, u_int len)
+{
+ if (active_state->packet_discard) {
+ active_state->keep_alive_timeouts = 0; /* ?? */
+ if (len >= active_state->packet_discard)
+ packet_stop_discard();
+ active_state->packet_discard -= len;
+ return;
+ }
+ buffer_append(&active_state->input, buf, len);
+}
+
+/* Returns a character from the packet. */
+
+u_int
+packet_get_char(void)
+{
+ char ch;
+
+ buffer_get(&active_state->incoming_packet, &ch, 1);
+ return (u_char) ch;
+}
+
+/* Returns an integer from the packet data. */
+
+u_int
+packet_get_int(void)
+{
+ return buffer_get_int(&active_state->incoming_packet);
+}
+
+/* Returns an 64 bit integer from the packet data. */
+
+u_int64_t
+packet_get_int64(void)
+{
+ return buffer_get_int64(&active_state->incoming_packet);
+}
+
+/*
+ * Returns an arbitrary precision integer from the packet data. The integer
+ * must have been initialized before this call.
+ */
+
+void
+packet_get_bignum(BIGNUM * value)
+{
+ buffer_get_bignum(&active_state->incoming_packet, value);
+}
+
+void
+packet_get_bignum2(BIGNUM * value)
+{
+ buffer_get_bignum2(&active_state->incoming_packet, value);
+}
+
+#ifdef OPENSSL_HAS_ECC
+void
+packet_get_ecpoint(const EC_GROUP *curve, EC_POINT *point)
+{
+ buffer_get_ecpoint(&active_state->incoming_packet, curve, point);
+}
+#endif
+
+void *
+packet_get_raw(u_int *length_ptr)
+{
+ u_int bytes = buffer_len(&active_state->incoming_packet);
+
+ if (length_ptr != NULL)
+ *length_ptr = bytes;
+ return buffer_ptr(&active_state->incoming_packet);
+}
+
+int
+packet_remaining(void)
+{
+ return buffer_len(&active_state->incoming_packet);
+}
+
+/*
+ * Returns a string from the packet data. The string is allocated using
+ * xmalloc; it is the responsibility of the calling program to free it when
+ * no longer needed. The length_ptr argument may be NULL, or point to an
+ * integer into which the length of the string is stored.
+ */
+
+void *
+packet_get_string(u_int *length_ptr)
+{
+ return buffer_get_string(&active_state->incoming_packet, length_ptr);
+}
+
+void *
+packet_get_string_ptr(u_int *length_ptr)
+{
+ return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr);
+}
+
+/* Ensures the returned string has no embedded \0 characters in it. */
+char *
+packet_get_cstring(u_int *length_ptr)
+{
+ return buffer_get_cstring(&active_state->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
+ * message is printed immediately, but only if the client is being executed
+ * in verbose mode. These messages are primarily intended to ease debugging
+ * authentication problems. The length of the formatted message must not
+ * exceed 1024 bytes. This will automatically call packet_write_wait.
+ */
+
+void
+packet_send_debug(const char *fmt,...)
+{
+ char buf[1024];
+ va_list args;
+
+ if (compat20 && (datafellows & SSH_BUG_DEBUG))
+ return;
+
+ va_start(args, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, args);
+ va_end(args);
+
+ if (compat20) {
+ packet_start(SSH2_MSG_DEBUG);
+ packet_put_char(0); /* bool: always display */
+ packet_put_cstring(buf);
+ packet_put_cstring("");
+ } else {
+ packet_start(SSH_MSG_DEBUG);
+ packet_put_cstring(buf);
+ }
+ packet_send();
+ packet_write_wait();
+}
+
+/*
+ * Logs the error plus constructs and sends a disconnect packet, closes the
+ * connection, and exits. This function never returns. The error message
+ * should not contain a newline. The length of the formatted message must
+ * not exceed 1024 bytes.
+ */
+
+void
+packet_disconnect(const char *fmt,...)
+{
+ char buf[1024];
+ va_list args;
+ static int disconnecting = 0;
+
+ if (disconnecting) /* Guard against recursive invocations. */
+ fatal("packet_disconnect called recursively.");
+ disconnecting = 1;
+
+ /*
+ * Format the message. Note that the caller must make sure the
+ * message is of limited size.
+ */
+ va_start(args, fmt);
+ 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);
+ packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
+ packet_put_cstring(buf);
+ packet_put_cstring("");
+ } else {
+ packet_start(SSH_MSG_DISCONNECT);
+ packet_put_cstring(buf);
+ }
+ packet_send();
+ packet_write_wait();
+
+ /* Stop listening for connections. */
+ channel_close_all();
+
+ /* Close the connection. */
+ packet_close();
+ cleanup_exit(255);
+}
+
+/* Checks if there is any buffered output, and tries to write some of the output. */
+
+void
+packet_write_poll(void)
+{
+ int len = buffer_len(&active_state->output);
+ int cont;
+
+ if (len > 0) {
+ cont = 0;
+ len = roaming_write(active_state->connection_out,
+ buffer_ptr(&active_state->output), len, &cont);
+ if (len == -1) {
+ if (errno == EINTR || errno == EAGAIN ||
+ errno == EWOULDBLOCK)
+ return;
+ fatal("Write failed: %.100s", strerror(errno));
+ }
+ if (len == 0 && !cont)
+ fatal("Write connection closed");
+ buffer_consume(&active_state->output, len);
+ }
+}
+
+/*
+ * Calls packet_write_poll repeatedly until all pending output data has been
+ * written.
+ */
+
+void
+packet_write_wait(void)
+{
+ fd_set *setp;
+ int ret, ms_remain;
+ struct timeval start, timeout, *timeoutp = NULL;
+
+ setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1,
+ NFDBITS), sizeof(fd_mask));
+ packet_write_poll();
+ while (packet_have_data_to_write()) {
+ memset(setp, 0, howmany(active_state->connection_out + 1,
+ NFDBITS) * sizeof(fd_mask));
+ FD_SET(active_state->connection_out, setp);
+
+ if (active_state->packet_timeout_ms > 0) {
+ ms_remain = active_state->packet_timeout_ms;
+ timeoutp = &timeout;
+ }
+ for (;;) {
+ if (active_state->packet_timeout_ms != -1) {
+ ms_to_timeval(&timeout, ms_remain);
+ gettimeofday(&start, NULL);
+ }
+ if ((ret = select(active_state->connection_out + 1,
+ NULL, setp, NULL, timeoutp)) >= 0)
+ break;
+ if (errno != EAGAIN && errno != EINTR &&
+ errno != EWOULDBLOCK)
+ break;
+ if (active_state->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);
+ }
+ packet_write_poll();
+ }
+ xfree(setp);
+}
+
+/* Returns true if there is buffered data to write to the connection. */
+
+int
+packet_have_data_to_write(void)
+{
+ return buffer_len(&active_state->output) != 0;
+}
+
+/* Returns true if there is not too much data to write to the connection. */
+
+int
+packet_not_very_much_data_to_write(void)
+{
+ if (active_state->interactive_mode)
+ return buffer_len(&active_state->output) < 16384;
+ else
+ return buffer_len(&active_state->output) < 128 * 1024;
+}
+
+static void
+packet_set_tos(int tos)
+{
+#ifndef IP_TOS_IS_BROKEN
+ if (!packet_connection_is_on_socket())
+ return;
+ switch (packet_connection_af()) {
+# ifdef IP_TOS
+ case AF_INET:
+ debug3("%s: set IP_TOS 0x%02x", __func__, tos);
+ if (setsockopt(active_state->connection_in,
+ IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
+ error("setsockopt IP_TOS %d: %.100s:",
+ tos, strerror(errno));
+ break;
+# endif /* IP_TOS */
+# ifdef IPV6_TCLASS
+ case AF_INET6:
+ debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
+ if (setsockopt(active_state->connection_in,
+ IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
+ error("setsockopt IPV6_TCLASS %d: %.100s:",
+ tos, strerror(errno));
+ break;
+# endif /* IPV6_TCLASS */
+ }
+#endif /* IP_TOS_IS_BROKEN */
+}
+
+/* Informs that the current session is interactive. Sets IP flags for that. */
+
+void
+packet_set_interactive(int interactive, int qos_interactive, int qos_bulk)
+{
+ if (active_state->set_interactive_called)
+ return;
+ active_state->set_interactive_called = 1;
+
+ /* Record that we are in interactive mode. */
+ active_state->interactive_mode = interactive;
+
+ /* Only set socket options if using a socket. */
+ if (!packet_connection_is_on_socket())
+ return;
+ set_nodelay(active_state->connection_in);
+ packet_set_tos(interactive ? qos_interactive : qos_bulk);
+}
+
+/* Returns true if the current connection is interactive. */
+
+int
+packet_is_interactive(void)
+{
+ return active_state->interactive_mode;
+}
+
+int
+packet_set_maxsize(u_int s)
+{
+ if (active_state->set_maxsize_called) {
+ logit("packet_set_maxsize: called twice: old %d new %d",
+ active_state->max_packet_size, s);
+ return -1;
+ }
+ if (s < 4 * 1024 || s > 1024 * 1024) {
+ logit("packet_set_maxsize: bad size %d", s);
+ return -1;
+ }
+ active_state->set_maxsize_called = 1;
+ debug("packet_set_maxsize: setting to %d", s);
+ active_state->max_packet_size = s;
+ return s;
+}
+
+int
+packet_inc_alive_timeouts(void)
+{
+ return ++active_state->keep_alive_timeouts;
+}
+
+void
+packet_set_alive_timeouts(int ka)
+{
+ active_state->keep_alive_timeouts = ka;
+}
+
+u_int
+packet_get_maxsize(void)
+{
+ return active_state->max_packet_size;
+}
+
+/* roundup current message to pad bytes */
+void
+packet_add_padding(u_char pad)
+{
+ active_state->extra_pad = pad;
+}
+
+/*
+ * 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
+ * protection measure against advanced traffic analysis techniques.
+ */
+void
+packet_send_ignore(int nbytes)
+{
+ 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)
+ rnd = arc4random();
+ packet_put_char((u_char)rnd & 0xff);
+ rnd >>= 8;
+ }
+}
+
+#define MAX_PACKETS (1U<<31)
+int
+packet_need_rekeying(void)
+{
+ if (datafellows & SSH_BUG_NOREKEY)
+ return 0;
+ return
+ (active_state->p_send.packets > MAX_PACKETS) ||
+ (active_state->p_read.packets > MAX_PACKETS) ||
+ (active_state->max_blocks_out &&
+ (active_state->p_send.blocks > active_state->max_blocks_out)) ||
+ (active_state->max_blocks_in &&
+ (active_state->p_read.blocks > active_state->max_blocks_in));
+}
+
+void
+packet_set_rekey_limit(u_int32_t bytes)
+{
+ active_state->rekey_limit = bytes;
+}
+
+void
+packet_set_server(void)
+{
+ active_state->server_side = 1;
+}
+
+void
+packet_set_authenticated(void)
+{
+ active_state->after_authentication = 1;
+}
+
+void *
+packet_get_input(void)
+{
+ return (void *)&active_state->input;
+}
+
+void *
+packet_get_output(void)
+{
+ return (void *)&active_state->output;
+}
+
+void *
+packet_get_newkeys(int mode)
+{
+ return (void *)active_state->newkeys[mode];
+}
+
+/*
+ * Save the state for the real connection, and use a separate state when
+ * resuming a suspended connection.
+ */
+void
+packet_backup_state(void)
+{
+ struct session_state *tmp;
+
+ close(active_state->connection_in);
+ active_state->connection_in = -1;
+ close(active_state->connection_out);
+ active_state->connection_out = -1;
+ if (backup_state)
+ tmp = backup_state;
+ else
+ tmp = alloc_session_state();
+ backup_state = active_state;
+ active_state = tmp;
+}
+
+/*
+ * Swap in the old state when resuming a connecion.
+ */
+void
+packet_restore_state(void)
+{
+ struct session_state *tmp;
+ void *buf;
+ u_int len;
+
+ tmp = backup_state;
+ backup_state = active_state;
+ active_state = tmp;
+ active_state->connection_in = backup_state->connection_in;
+ backup_state->connection_in = -1;
+ active_state->connection_out = backup_state->connection_out;
+ backup_state->connection_out = -1;
+ len = buffer_len(&backup_state->input);
+ if (len > 0) {
+ buf = buffer_ptr(&backup_state->input);
+ buffer_append(&active_state->input, buf, len);
+ buffer_clear(&backup_state->input);
+ add_recv_bytes(len);
+ }
+}