| /* $OpenBSD: packet.c,v 1.237 2016/09/12 01:22:38 deraadt 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/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 <netdb.h> |
| #include <stdarg.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <limits.h> |
| #include <signal.h> |
| #include <time.h> |
| |
| #include <zlib.h> |
| |
| #include "buffer.h" /* typedefs XXX */ |
| #include "key.h" /* typedefs XXX */ |
| |
| #include "xmalloc.h" |
| #include "crc32.h" |
| #include "deattack.h" |
| #include "compat.h" |
| #include "ssh1.h" |
| #include "ssh2.h" |
| #include "cipher.h" |
| #include "sshkey.h" |
| #include "kex.h" |
| #include "digest.h" |
| #include "mac.h" |
| #include "log.h" |
| #include "canohost.h" |
| #include "misc.h" |
| #include "channels.h" |
| #include "ssh.h" |
| #include "packet.h" |
| #include "ssherr.h" |
| #include "sshbuf.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; |
| struct sshbuf *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. */ |
| struct sshcipher_ctx *receive_context; |
| |
| /* Encryption context for sending data. Only used for encryption. */ |
| struct sshcipher_ctx *send_context; |
| |
| /* Buffer for raw input data from the socket. */ |
| struct sshbuf *input; |
| |
| /* Buffer for raw output data going to the socket. */ |
| struct sshbuf *output; |
| |
| /* Buffer for the partial outgoing packet being constructed. */ |
| struct sshbuf *outgoing_packet; |
| |
| /* Buffer for the incoming packet currently being processed. */ |
| struct sshbuf *incoming_packet; |
| |
| /* Scratch buffer for packet compression/decompression. */ |
| struct sshbuf *compression_buffer; |
| |
| /* Incoming/outgoing compression dictionaries */ |
| z_stream compression_in_stream; |
| z_stream compression_out_stream; |
| int compression_in_started; |
| int compression_out_started; |
| int compression_in_failures; |
| int compression_out_failures; |
| |
| /* |
| * 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 */ |
| struct newkeys *newkeys[MODE_MAX]; |
| struct packet_state p_read, p_send; |
| |
| /* Volume-based rekeying */ |
| u_int64_t max_blocks_in, max_blocks_out, rekey_limit; |
| |
| /* Time-based rekeying */ |
| u_int32_t rekey_interval; /* how often in seconds */ |
| time_t rekey_time; /* time of last rekeying */ |
| |
| /* 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; |
| size_t packet_discard_mac_already; |
| struct sshmac *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; |
| |
| /* One-off warning about weak ciphers */ |
| int cipher_warning_done; |
| |
| /* SSH1 CRC compensation attack detector */ |
| struct deattack_ctx deattack; |
| |
| TAILQ_HEAD(, packet) outgoing; |
| }; |
| |
| struct ssh * |
| ssh_alloc_session_state(void) |
| { |
| struct ssh *ssh = NULL; |
| struct session_state *state = NULL; |
| |
| if ((ssh = calloc(1, sizeof(*ssh))) == NULL || |
| (state = calloc(1, sizeof(*state))) == NULL || |
| (state->input = sshbuf_new()) == NULL || |
| (state->output = sshbuf_new()) == NULL || |
| (state->outgoing_packet = sshbuf_new()) == NULL || |
| (state->incoming_packet = sshbuf_new()) == NULL) |
| goto fail; |
| TAILQ_INIT(&state->outgoing); |
| TAILQ_INIT(&ssh->private_keys); |
| TAILQ_INIT(&ssh->public_keys); |
| state->connection_in = -1; |
| state->connection_out = -1; |
| state->max_packet_size = 32768; |
| state->packet_timeout_ms = -1; |
| state->p_send.packets = state->p_read.packets = 0; |
| state->initialized = 1; |
| /* |
| * ssh_packet_send2() needs to queue packets until |
| * we've done the initial key exchange. |
| */ |
| state->rekeying = 1; |
| ssh->state = state; |
| return ssh; |
| fail: |
| if (state) { |
| sshbuf_free(state->input); |
| sshbuf_free(state->output); |
| sshbuf_free(state->incoming_packet); |
| sshbuf_free(state->outgoing_packet); |
| free(state); |
| } |
| free(ssh); |
| return NULL; |
| } |
| |
| /* Returns nonzero if rekeying is in progress */ |
| int |
| ssh_packet_is_rekeying(struct ssh *ssh) |
| { |
| return compat20 && |
| (ssh->state->rekeying || (ssh->kex != NULL && ssh->kex->done == 0)); |
| } |
| |
| /* |
| * Sets the descriptors used for communication. Disables encryption until |
| * packet_set_encryption_key is called. |
| */ |
| struct ssh * |
| ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out) |
| { |
| struct session_state *state; |
| const struct sshcipher *none = cipher_by_name("none"); |
| int r; |
| |
| if (none == NULL) { |
| error("%s: cannot load cipher 'none'", __func__); |
| return NULL; |
| } |
| if (ssh == NULL) |
| ssh = ssh_alloc_session_state(); |
| if (ssh == NULL) { |
| error("%s: cound not allocate state", __func__); |
| return NULL; |
| } |
| state = ssh->state; |
| state->connection_in = fd_in; |
| state->connection_out = fd_out; |
| if ((r = cipher_init(&state->send_context, none, |
| (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 || |
| (r = cipher_init(&state->receive_context, none, |
| (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) { |
| error("%s: cipher_init failed: %s", __func__, ssh_err(r)); |
| free(ssh); /* XXX need ssh_free_session_state? */ |
| return NULL; |
| } |
| state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL; |
| deattack_init(&state->deattack); |
| /* |
| * Cache the IP address of the remote connection for use in error |
| * messages that might be generated after the connection has closed. |
| */ |
| (void)ssh_remote_ipaddr(ssh); |
| return ssh; |
| } |
| |
| void |
| ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count) |
| { |
| struct session_state *state = ssh->state; |
| |
| if (timeout <= 0 || count <= 0) { |
| state->packet_timeout_ms = -1; |
| return; |
| } |
| if ((INT_MAX / 1000) / count < timeout) |
| state->packet_timeout_ms = INT_MAX; |
| else |
| state->packet_timeout_ms = timeout * count * 1000; |
| } |
| |
| int |
| ssh_packet_stop_discard(struct ssh *ssh) |
| { |
| struct session_state *state = ssh->state; |
| int r; |
| |
| if (state->packet_discard_mac) { |
| char buf[1024]; |
| size_t dlen = PACKET_MAX_SIZE; |
| |
| if (dlen > state->packet_discard_mac_already) |
| dlen -= state->packet_discard_mac_already; |
| memset(buf, 'a', sizeof(buf)); |
| while (sshbuf_len(state->incoming_packet) < dlen) |
| if ((r = sshbuf_put(state->incoming_packet, buf, |
| sizeof(buf))) != 0) |
| return r; |
| (void) mac_compute(state->packet_discard_mac, |
| state->p_read.seqnr, |
| sshbuf_ptr(state->incoming_packet), dlen, |
| NULL, 0); |
| } |
| logit("Finished discarding for %.200s port %d", |
| ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); |
| return SSH_ERR_MAC_INVALID; |
| } |
| |
| static int |
| ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc, |
| struct sshmac *mac, size_t mac_already, u_int discard) |
| { |
| struct session_state *state = ssh->state; |
| int r; |
| |
| if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) { |
| if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0) |
| return r; |
| return SSH_ERR_MAC_INVALID; |
| } |
| /* |
| * Record number of bytes over which the mac has already |
| * been computed in order to minimize timing attacks. |
| */ |
| if (mac && mac->enabled) { |
| state->packet_discard_mac = mac; |
| state->packet_discard_mac_already = mac_already; |
| } |
| if (sshbuf_len(state->input) >= discard) |
| return ssh_packet_stop_discard(ssh); |
| state->packet_discard = discard - sshbuf_len(state->input); |
| return 0; |
| } |
| |
| /* Returns 1 if remote host is connected via socket, 0 if not. */ |
| |
| int |
| ssh_packet_connection_is_on_socket(struct ssh *ssh) |
| { |
| struct session_state *state = ssh->state; |
| struct sockaddr_storage from, to; |
| socklen_t fromlen, tolen; |
| |
| if (state->connection_in == -1 || state->connection_out == -1) |
| return 0; |
| |
| /* filedescriptors in and out are the same, so it's a socket */ |
| if (state->connection_in == state->connection_out) |
| return 1; |
| fromlen = sizeof(from); |
| memset(&from, 0, sizeof(from)); |
| if (getpeername(state->connection_in, (struct sockaddr *)&from, |
| &fromlen) < 0) |
| return 0; |
| tolen = sizeof(to); |
| memset(&to, 0, sizeof(to)); |
| if (getpeername(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; |
| } |
| |
| void |
| ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes) |
| { |
| if (ibytes) |
| *ibytes = ssh->state->p_read.bytes; |
| if (obytes) |
| *obytes = ssh->state->p_send.bytes; |
| } |
| |
| int |
| ssh_packet_connection_af(struct ssh *ssh) |
| { |
| struct sockaddr_storage to; |
| socklen_t tolen = sizeof(to); |
| |
| memset(&to, 0, sizeof(to)); |
| if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to, |
| &tolen) < 0) |
| return 0; |
| #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 |
| ssh_packet_set_nonblocking(struct ssh *ssh) |
| { |
| /* Set the socket into non-blocking mode. */ |
| set_nonblock(ssh->state->connection_in); |
| |
| if (ssh->state->connection_out != ssh->state->connection_in) |
| set_nonblock(ssh->state->connection_out); |
| } |
| |
| /* Returns the socket used for reading. */ |
| |
| int |
| ssh_packet_get_connection_in(struct ssh *ssh) |
| { |
| return ssh->state->connection_in; |
| } |
| |
| /* Returns the descriptor used for writing. */ |
| |
| int |
| ssh_packet_get_connection_out(struct ssh *ssh) |
| { |
| return ssh->state->connection_out; |
| } |
| |
| /* |
| * Returns the IP-address of the remote host as a string. The returned |
| * string must not be freed. |
| */ |
| |
| const char * |
| ssh_remote_ipaddr(struct ssh *ssh) |
| { |
| const int sock = ssh->state->connection_in; |
| |
| /* Check whether we have cached the ipaddr. */ |
| if (ssh->remote_ipaddr == NULL) { |
| if (ssh_packet_connection_is_on_socket(ssh)) { |
| ssh->remote_ipaddr = get_peer_ipaddr(sock); |
| ssh->remote_port = get_peer_port(sock); |
| ssh->local_ipaddr = get_local_ipaddr(sock); |
| ssh->local_port = get_local_port(sock); |
| } else { |
| ssh->remote_ipaddr = strdup("UNKNOWN"); |
| ssh->remote_port = 65535; |
| ssh->local_ipaddr = strdup("UNKNOWN"); |
| ssh->local_port = 65535; |
| } |
| } |
| return ssh->remote_ipaddr; |
| } |
| |
| /* Returns the port number of the remote host. */ |
| |
| int |
| ssh_remote_port(struct ssh *ssh) |
| { |
| (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */ |
| return ssh->remote_port; |
| } |
| |
| /* |
| * Returns the IP-address of the local host as a string. The returned |
| * string must not be freed. |
| */ |
| |
| const char * |
| ssh_local_ipaddr(struct ssh *ssh) |
| { |
| (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */ |
| return ssh->local_ipaddr; |
| } |
| |
| /* Returns the port number of the local host. */ |
| |
| int |
| ssh_local_port(struct ssh *ssh) |
| { |
| (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */ |
| return ssh->local_port; |
| } |
| |
| /* Closes the connection and clears and frees internal data structures. */ |
| |
| void |
| ssh_packet_close(struct ssh *ssh) |
| { |
| struct session_state *state = ssh->state; |
| u_int mode; |
| |
| if (!state->initialized) |
| return; |
| state->initialized = 0; |
| if (state->connection_in == state->connection_out) { |
| shutdown(state->connection_out, SHUT_RDWR); |
| close(state->connection_out); |
| } else { |
| close(state->connection_in); |
| close(state->connection_out); |
| } |
| sshbuf_free(state->input); |
| sshbuf_free(state->output); |
| sshbuf_free(state->outgoing_packet); |
| sshbuf_free(state->incoming_packet); |
| for (mode = 0; mode < MODE_MAX; mode++) |
| kex_free_newkeys(state->newkeys[mode]); |
| if (state->compression_buffer) { |
| sshbuf_free(state->compression_buffer); |
| if (state->compression_out_started) { |
| z_streamp stream = &state->compression_out_stream; |
| debug("compress outgoing: " |
| "raw data %llu, compressed %llu, factor %.2f", |
| (unsigned long long)stream->total_in, |
| (unsigned long long)stream->total_out, |
| stream->total_in == 0 ? 0.0 : |
| (double) stream->total_out / stream->total_in); |
| if (state->compression_out_failures == 0) |
| deflateEnd(stream); |
| } |
| if (state->compression_in_started) { |
| z_streamp stream = &state->compression_out_stream; |
| debug("compress incoming: " |
| "raw data %llu, compressed %llu, factor %.2f", |
| (unsigned long long)stream->total_out, |
| (unsigned long long)stream->total_in, |
| stream->total_out == 0 ? 0.0 : |
| (double) stream->total_in / stream->total_out); |
| if (state->compression_in_failures == 0) |
| inflateEnd(stream); |
| } |
| } |
| cipher_free(state->send_context); |
| cipher_free(state->receive_context); |
| state->send_context = state->receive_context = NULL; |
| free(ssh->remote_ipaddr); |
| ssh->remote_ipaddr = NULL; |
| free(ssh->state); |
| ssh->state = NULL; |
| } |
| |
| /* Sets remote side protocol flags. */ |
| |
| void |
| ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags) |
| { |
| ssh->state->remote_protocol_flags = protocol_flags; |
| } |
| |
| /* Returns the remote protocol flags set earlier by the above function. */ |
| |
| u_int |
| ssh_packet_get_protocol_flags(struct ssh *ssh) |
| { |
| return ssh->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 int |
| ssh_packet_init_compression(struct ssh *ssh) |
| { |
| if (!ssh->state->compression_buffer && |
| ((ssh->state->compression_buffer = sshbuf_new()) == NULL)) |
| return SSH_ERR_ALLOC_FAIL; |
| return 0; |
| } |
| |
| static int |
| start_compression_out(struct ssh *ssh, int level) |
| { |
| if (level < 1 || level > 9) |
| return SSH_ERR_INVALID_ARGUMENT; |
| debug("Enabling compression at level %d.", level); |
| if (ssh->state->compression_out_started == 1) |
| deflateEnd(&ssh->state->compression_out_stream); |
| switch (deflateInit(&ssh->state->compression_out_stream, level)) { |
| case Z_OK: |
| ssh->state->compression_out_started = 1; |
| break; |
| case Z_MEM_ERROR: |
| return SSH_ERR_ALLOC_FAIL; |
| default: |
| return SSH_ERR_INTERNAL_ERROR; |
| } |
| return 0; |
| } |
| |
| static int |
| start_compression_in(struct ssh *ssh) |
| { |
| if (ssh->state->compression_in_started == 1) |
| inflateEnd(&ssh->state->compression_in_stream); |
| switch (inflateInit(&ssh->state->compression_in_stream)) { |
| case Z_OK: |
| ssh->state->compression_in_started = 1; |
| break; |
| case Z_MEM_ERROR: |
| return SSH_ERR_ALLOC_FAIL; |
| default: |
| return SSH_ERR_INTERNAL_ERROR; |
| } |
| return 0; |
| } |
| |
| int |
| ssh_packet_start_compression(struct ssh *ssh, int level) |
| { |
| int r; |
| |
| if (ssh->state->packet_compression && !compat20) |
| return SSH_ERR_INTERNAL_ERROR; |
| ssh->state->packet_compression = 1; |
| if ((r = ssh_packet_init_compression(ssh)) != 0 || |
| (r = start_compression_in(ssh)) != 0 || |
| (r = start_compression_out(ssh, level)) != 0) |
| return r; |
| return 0; |
| } |
| |
| /* XXX remove need for separate compression buffer */ |
| static int |
| compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out) |
| { |
| u_char buf[4096]; |
| int r, status; |
| |
| if (ssh->state->compression_out_started != 1) |
| return SSH_ERR_INTERNAL_ERROR; |
| |
| /* This case is not handled below. */ |
| if (sshbuf_len(in) == 0) |
| return 0; |
| |
| /* Input is the contents of the input buffer. */ |
| if ((ssh->state->compression_out_stream.next_in = |
| sshbuf_mutable_ptr(in)) == NULL) |
| return SSH_ERR_INTERNAL_ERROR; |
| ssh->state->compression_out_stream.avail_in = sshbuf_len(in); |
| |
| /* Loop compressing until deflate() returns with avail_out != 0. */ |
| do { |
| /* Set up fixed-size output buffer. */ |
| ssh->state->compression_out_stream.next_out = buf; |
| ssh->state->compression_out_stream.avail_out = sizeof(buf); |
| |
| /* Compress as much data into the buffer as possible. */ |
| status = deflate(&ssh->state->compression_out_stream, |
| Z_PARTIAL_FLUSH); |
| switch (status) { |
| case Z_MEM_ERROR: |
| return SSH_ERR_ALLOC_FAIL; |
| case Z_OK: |
| /* Append compressed data to output_buffer. */ |
| if ((r = sshbuf_put(out, buf, sizeof(buf) - |
| ssh->state->compression_out_stream.avail_out)) != 0) |
| return r; |
| break; |
| case Z_STREAM_ERROR: |
| default: |
| ssh->state->compression_out_failures++; |
| return SSH_ERR_INVALID_FORMAT; |
| } |
| } while (ssh->state->compression_out_stream.avail_out == 0); |
| return 0; |
| } |
| |
| static int |
| uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out) |
| { |
| u_char buf[4096]; |
| int r, status; |
| |
| if (ssh->state->compression_in_started != 1) |
| return SSH_ERR_INTERNAL_ERROR; |
| |
| if ((ssh->state->compression_in_stream.next_in = |
| sshbuf_mutable_ptr(in)) == NULL) |
| return SSH_ERR_INTERNAL_ERROR; |
| ssh->state->compression_in_stream.avail_in = sshbuf_len(in); |
| |
| for (;;) { |
| /* Set up fixed-size output buffer. */ |
| ssh->state->compression_in_stream.next_out = buf; |
| ssh->state->compression_in_stream.avail_out = sizeof(buf); |
| |
| status = inflate(&ssh->state->compression_in_stream, |
| Z_PARTIAL_FLUSH); |
| switch (status) { |
| case Z_OK: |
| if ((r = sshbuf_put(out, buf, sizeof(buf) - |
| ssh->state->compression_in_stream.avail_out)) != 0) |
| return r; |
| break; |
| case Z_BUF_ERROR: |
| /* |
| * Comments in zlib.h say that we should keep calling |
| * inflate() until we get an error. This appears to |
| * be the error that we get. |
| */ |
| return 0; |
| case Z_DATA_ERROR: |
| return SSH_ERR_INVALID_FORMAT; |
| case Z_MEM_ERROR: |
| return SSH_ERR_ALLOC_FAIL; |
| case Z_STREAM_ERROR: |
| default: |
| ssh->state->compression_in_failures++; |
| return SSH_ERR_INTERNAL_ERROR; |
| } |
| } |
| /* NOTREACHED */ |
| } |
| |
| /* Serialise compression state into a blob for privsep */ |
| static int |
| ssh_packet_get_compress_state(struct sshbuf *m, struct ssh *ssh) |
| { |
| struct session_state *state = ssh->state; |
| struct sshbuf *b; |
| int r; |
| |
| if ((b = sshbuf_new()) == NULL) |
| return SSH_ERR_ALLOC_FAIL; |
| if (state->compression_in_started) { |
| if ((r = sshbuf_put_string(b, &state->compression_in_stream, |
| sizeof(state->compression_in_stream))) != 0) |
| goto out; |
| } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0) |
| goto out; |
| if (state->compression_out_started) { |
| if ((r = sshbuf_put_string(b, &state->compression_out_stream, |
| sizeof(state->compression_out_stream))) != 0) |
| goto out; |
| } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0) |
| goto out; |
| r = sshbuf_put_stringb(m, b); |
| out: |
| sshbuf_free(b); |
| return r; |
| } |
| |
| /* Deserialise compression state from a blob for privsep */ |
| static int |
| ssh_packet_set_compress_state(struct ssh *ssh, struct sshbuf *m) |
| { |
| struct session_state *state = ssh->state; |
| struct sshbuf *b = NULL; |
| int r; |
| const u_char *inblob, *outblob; |
| size_t inl, outl; |
| |
| if ((r = sshbuf_froms(m, &b)) != 0) |
| goto out; |
| if ((r = sshbuf_get_string_direct(b, &inblob, &inl)) != 0 || |
| (r = sshbuf_get_string_direct(b, &outblob, &outl)) != 0) |
| goto out; |
| if (inl == 0) |
| state->compression_in_started = 0; |
| else if (inl != sizeof(state->compression_in_stream)) { |
| r = SSH_ERR_INTERNAL_ERROR; |
| goto out; |
| } else { |
| state->compression_in_started = 1; |
| memcpy(&state->compression_in_stream, inblob, inl); |
| } |
| if (outl == 0) |
| state->compression_out_started = 0; |
| else if (outl != sizeof(state->compression_out_stream)) { |
| r = SSH_ERR_INTERNAL_ERROR; |
| goto out; |
| } else { |
| state->compression_out_started = 1; |
| memcpy(&state->compression_out_stream, outblob, outl); |
| } |
| r = 0; |
| out: |
| sshbuf_free(b); |
| return r; |
| } |
| |
| void |
| ssh_packet_set_compress_hooks(struct ssh *ssh, void *ctx, |
| void *(*allocfunc)(void *, u_int, u_int), |
| void (*freefunc)(void *, void *)) |
| { |
| ssh->state->compression_out_stream.zalloc = (alloc_func)allocfunc; |
| ssh->state->compression_out_stream.zfree = (free_func)freefunc; |
| ssh->state->compression_out_stream.opaque = ctx; |
| ssh->state->compression_in_stream.zalloc = (alloc_func)allocfunc; |
| ssh->state->compression_in_stream.zfree = (free_func)freefunc; |
| ssh->state->compression_in_stream.opaque = ctx; |
| } |
| |
| /* |
| * 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 |
| ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number) |
| { |
| #ifndef WITH_SSH1 |
| fatal("no SSH protocol 1 support"); |
| #else /* WITH_SSH1 */ |
| struct session_state *state = ssh->state; |
| const struct sshcipher *cipher = cipher_by_number(number); |
| int r; |
| const char *wmsg; |
| |
| if (cipher == NULL) |
| fatal("%s: unknown cipher number %d", __func__, number); |
| if (keylen < 20) |
| fatal("%s: keylen too small: %d", __func__, keylen); |
| if (keylen > SSH_SESSION_KEY_LENGTH) |
| fatal("%s: keylen too big: %d", __func__, keylen); |
| memcpy(state->ssh1_key, key, keylen); |
| state->ssh1_keylen = keylen; |
| if ((r = cipher_init(&state->send_context, cipher, key, keylen, |
| NULL, 0, CIPHER_ENCRYPT)) != 0 || |
| (r = cipher_init(&state->receive_context, cipher, key, keylen, |
| NULL, 0, CIPHER_DECRYPT) != 0)) |
| fatal("%s: cipher_init failed: %s", __func__, ssh_err(r)); |
| if (!state->cipher_warning_done && |
| ((wmsg = cipher_warning_message(state->send_context)) != NULL || |
| (wmsg = cipher_warning_message(state->send_context)) != NULL)) { |
| error("Warning: %s", wmsg); |
| state->cipher_warning_done = 1; |
| } |
| #endif /* WITH_SSH1 */ |
| } |
| |
| /* |
| * Finalizes and sends the packet. If the encryption key has been set, |
| * encrypts the packet before sending. |
| */ |
| |
| int |
| ssh_packet_send1(struct ssh *ssh) |
| { |
| struct session_state *state = ssh->state; |
| u_char buf[8], *cp; |
| int r, padding, len; |
| u_int checksum; |
| |
| /* |
| * If using packet compression, compress the payload of the outgoing |
| * packet. |
| */ |
| if (state->packet_compression) { |
| sshbuf_reset(state->compression_buffer); |
| /* Skip padding. */ |
| if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0) |
| goto out; |
| /* padding */ |
| if ((r = sshbuf_put(state->compression_buffer, |
| "\0\0\0\0\0\0\0\0", 8)) != 0) |
| goto out; |
| if ((r = compress_buffer(ssh, state->outgoing_packet, |
| state->compression_buffer)) != 0) |
| goto out; |
| sshbuf_reset(state->outgoing_packet); |
| if ((r = sshbuf_putb(state->outgoing_packet, |
| state->compression_buffer)) != 0) |
| goto out; |
| } |
| /* Compute packet length without padding (add checksum, remove padding). */ |
| len = sshbuf_len(state->outgoing_packet) + 4 - 8; |
| |
| /* Insert padding. Initialized to zero in packet_start1() */ |
| padding = 8 - len % 8; |
| if (!cipher_ctx_is_plaintext(state->send_context)) { |
| cp = sshbuf_mutable_ptr(state->outgoing_packet); |
| if (cp == NULL) { |
| r = SSH_ERR_INTERNAL_ERROR; |
| goto out; |
| } |
| arc4random_buf(cp + 8 - padding, padding); |
| } |
| if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0) |
| goto out; |
| |
| /* Add check bytes. */ |
| checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet), |
| sshbuf_len(state->outgoing_packet)); |
| POKE_U32(buf, checksum); |
| if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0) |
| goto out; |
| |
| #ifdef PACKET_DEBUG |
| fprintf(stderr, "packet_send plain: "); |
| sshbuf_dump(state->outgoing_packet, stderr); |
| #endif |
| |
| /* Append to output. */ |
| POKE_U32(buf, len); |
| if ((r = sshbuf_put(state->output, buf, 4)) != 0) |
| goto out; |
| if ((r = sshbuf_reserve(state->output, |
| sshbuf_len(state->outgoing_packet), &cp)) != 0) |
| goto out; |
| if ((r = cipher_crypt(state->send_context, 0, cp, |
| sshbuf_ptr(state->outgoing_packet), |
| sshbuf_len(state->outgoing_packet), 0, 0)) != 0) |
| goto out; |
| |
| #ifdef PACKET_DEBUG |
| fprintf(stderr, "encrypted: "); |
| sshbuf_dump(state->output, stderr); |
| #endif |
| state->p_send.packets++; |
| state->p_send.bytes += len + |
| sshbuf_len(state->outgoing_packet); |
| sshbuf_reset(state->outgoing_packet); |
| |
| /* |
| * Note that the packet is now only buffered in output. It won't be |
| * actually sent until ssh_packet_write_wait or ssh_packet_write_poll |
| * is called. |
| */ |
| r = 0; |
| out: |
| return r; |
| } |
| |
| int |
| ssh_set_newkeys(struct ssh *ssh, int mode) |
| { |
| struct session_state *state = ssh->state; |
| struct sshenc *enc; |
| struct sshmac *mac; |
| struct sshcomp *comp; |
| struct sshcipher_ctx **ccp; |
| struct packet_state *ps; |
| u_int64_t *max_blocks; |
| const char *wmsg, *dir; |
| int r, crypt_type; |
| |
| debug2("set_newkeys: mode %d", mode); |
| |
| if (mode == MODE_OUT) { |
| dir = "output"; |
| ccp = &state->send_context; |
| crypt_type = CIPHER_ENCRYPT; |
| ps = &state->p_send; |
| max_blocks = &state->max_blocks_out; |
| } else { |
| dir = "input"; |
| ccp = &state->receive_context; |
| crypt_type = CIPHER_DECRYPT; |
| ps = &state->p_read; |
| max_blocks = &state->max_blocks_in; |
| } |
| if (state->newkeys[mode] != NULL) { |
| debug("%s: rekeying after %llu %s blocks" |
| " (%llu bytes total)", __func__, |
| (unsigned long long)ps->blocks, dir, |
| (unsigned long long)ps->bytes); |
| cipher_free(*ccp); |
| *ccp = NULL; |
| enc = &state->newkeys[mode]->enc; |
| mac = &state->newkeys[mode]->mac; |
| comp = &state->newkeys[mode]->comp; |
| mac_clear(mac); |
| explicit_bzero(enc->iv, enc->iv_len); |
| explicit_bzero(enc->key, enc->key_len); |
| explicit_bzero(mac->key, mac->key_len); |
| free(enc->name); |
| free(enc->iv); |
| free(enc->key); |
| free(mac->name); |
| free(mac->key); |
| free(comp->name); |
| free(state->newkeys[mode]); |
| } |
| /* note that both bytes and the seqnr are not reset */ |
| ps->packets = ps->blocks = 0; |
| /* move newkeys from kex to state */ |
| if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL) |
| return SSH_ERR_INTERNAL_ERROR; |
| ssh->kex->newkeys[mode] = NULL; |
| enc = &state->newkeys[mode]->enc; |
| mac = &state->newkeys[mode]->mac; |
| comp = &state->newkeys[mode]->comp; |
| if (cipher_authlen(enc->cipher) == 0) { |
| if ((r = mac_init(mac)) != 0) |
| return r; |
| } |
| mac->enabled = 1; |
| DBG(debug("cipher_init_context: %d", mode)); |
| if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len, |
| enc->iv, enc->iv_len, crypt_type)) != 0) |
| return r; |
| if (!state->cipher_warning_done && |
| (wmsg = cipher_warning_message(*ccp)) != NULL) { |
| error("Warning: %s", wmsg); |
| state->cipher_warning_done = 1; |
| } |
| /* Deleting the keys does not gain extra security */ |
| /* explicit_bzero(enc->iv, enc->block_size); |
| explicit_bzero(enc->key, enc->key_len); |
| explicit_bzero(mac->key, mac->key_len); */ |
| if ((comp->type == COMP_ZLIB || |
| (comp->type == COMP_DELAYED && |
| state->after_authentication)) && comp->enabled == 0) { |
| if ((r = ssh_packet_init_compression(ssh)) < 0) |
| return r; |
| if (mode == MODE_OUT) { |
| if ((r = start_compression_out(ssh, 6)) != 0) |
| return r; |
| } else { |
| if ((r = start_compression_in(ssh)) != 0) |
| return r; |
| } |
| 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 (state->rekey_limit) |
| *max_blocks = MINIMUM(*max_blocks, |
| state->rekey_limit / enc->block_size); |
| debug("rekey after %llu blocks", (unsigned long long)*max_blocks); |
| return 0; |
| } |
| |
| #define MAX_PACKETS (1U<<31) |
| static int |
| ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len) |
| { |
| struct session_state *state = ssh->state; |
| u_int32_t out_blocks; |
| |
| /* XXX client can't cope with rekeying pre-auth */ |
| if (!state->after_authentication) |
| return 0; |
| |
| /* Haven't keyed yet or KEX in progress. */ |
| if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh)) |
| return 0; |
| |
| /* Peer can't rekey */ |
| if (ssh->compat & SSH_BUG_NOREKEY) |
| return 0; |
| |
| /* |
| * Permit one packet in or out per rekey - this allows us to |
| * make progress when rekey limits are very small. |
| */ |
| if (state->p_send.packets == 0 && state->p_read.packets == 0) |
| return 0; |
| |
| /* Time-based rekeying */ |
| if (state->rekey_interval != 0 && |
| state->rekey_time + state->rekey_interval <= monotime()) |
| return 1; |
| |
| /* Always rekey when MAX_PACKETS sent in either direction */ |
| if (state->p_send.packets > MAX_PACKETS || |
| state->p_read.packets > MAX_PACKETS) |
| return 1; |
| |
| /* Rekey after (cipher-specific) maxiumum blocks */ |
| out_blocks = ROUNDUP(outbound_packet_len, |
| state->newkeys[MODE_OUT]->enc.block_size); |
| return (state->max_blocks_out && |
| (state->p_send.blocks + out_blocks > state->max_blocks_out)) || |
| (state->max_blocks_in && |
| (state->p_read.blocks > state->max_blocks_in)); |
| } |
| |
| /* |
| * 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 int |
| ssh_packet_enable_delayed_compress(struct ssh *ssh) |
| { |
| struct session_state *state = ssh->state; |
| struct sshcomp *comp = NULL; |
| int r, mode; |
| |
| /* |
| * Remember that we are past the authentication step, so rekeying |
| * with COMP_DELAYED will turn on compression immediately. |
| */ |
| state->after_authentication = 1; |
| for (mode = 0; mode < MODE_MAX; mode++) { |
| /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */ |
| if (state->newkeys[mode] == NULL) |
| continue; |
| comp = &state->newkeys[mode]->comp; |
| if (comp && !comp->enabled && comp->type == COMP_DELAYED) { |
| if ((r = ssh_packet_init_compression(ssh)) != 0) |
| return r; |
| if (mode == MODE_OUT) { |
| if ((r = start_compression_out(ssh, 6)) != 0) |
| return r; |
| } else { |
| if ((r = start_compression_in(ssh)) != 0) |
| return r; |
| } |
| comp->enabled = 1; |
| } |
| } |
| return 0; |
| } |
| |
| /* Used to mute debug logging for noisy packet types */ |
| static int |
| ssh_packet_log_type(u_char type) |
| { |
| switch (type) { |
| case SSH2_MSG_CHANNEL_DATA: |
| case SSH2_MSG_CHANNEL_EXTENDED_DATA: |
| case SSH2_MSG_CHANNEL_WINDOW_ADJUST: |
| return 0; |
| default: |
| return 1; |
| } |
| } |
| |
| /* |
| * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) |
| */ |
| int |
| ssh_packet_send2_wrapped(struct ssh *ssh) |
| { |
| struct session_state *state = ssh->state; |
| u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH]; |
| u_char tmp, padlen, pad = 0; |
| u_int authlen = 0, aadlen = 0; |
| u_int len; |
| struct sshenc *enc = NULL; |
| struct sshmac *mac = NULL; |
| struct sshcomp *comp = NULL; |
| int r, block_size; |
| |
| if (state->newkeys[MODE_OUT] != NULL) { |
| enc = &state->newkeys[MODE_OUT]->enc; |
| mac = &state->newkeys[MODE_OUT]->mac; |
| comp = &state->newkeys[MODE_OUT]->comp; |
| /* disable mac for authenticated encryption */ |
| if ((authlen = cipher_authlen(enc->cipher)) != 0) |
| mac = NULL; |
| } |
| block_size = enc ? enc->block_size : 8; |
| aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0; |
| |
| type = (sshbuf_ptr(state->outgoing_packet))[5]; |
| if (ssh_packet_log_type(type)) |
| debug3("send packet: type %u", type); |
| #ifdef PACKET_DEBUG |
| fprintf(stderr, "plain: "); |
| sshbuf_dump(state->outgoing_packet, stderr); |
| #endif |
| |
| if (comp && comp->enabled) { |
| len = sshbuf_len(state->outgoing_packet); |
| /* skip header, compress only payload */ |
| if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0) |
| goto out; |
| sshbuf_reset(state->compression_buffer); |
| if ((r = compress_buffer(ssh, state->outgoing_packet, |
| state->compression_buffer)) != 0) |
| goto out; |
| sshbuf_reset(state->outgoing_packet); |
| if ((r = sshbuf_put(state->outgoing_packet, |
| "\0\0\0\0\0", 5)) != 0 || |
| (r = sshbuf_putb(state->outgoing_packet, |
| state->compression_buffer)) != 0) |
| goto out; |
| DBG(debug("compression: raw %d compressed %zd", len, |
| sshbuf_len(state->outgoing_packet))); |
| } |
| |
| /* sizeof (packet_len + pad_len + payload) */ |
| len = sshbuf_len(state->outgoing_packet); |
| |
| /* |
| * calc size of padding, alloc space, get random data, |
| * minimum padding is 4 bytes |
| */ |
| len -= aadlen; /* packet length is not encrypted for EtM modes */ |
| padlen = block_size - (len % block_size); |
| if (padlen < 4) |
| padlen += block_size; |
| if (state->extra_pad) { |
| tmp = state->extra_pad; |
| state->extra_pad = |
| ROUNDUP(state->extra_pad, block_size); |
| /* check if roundup overflowed */ |
| if (state->extra_pad < tmp) |
| return SSH_ERR_INVALID_ARGUMENT; |
| tmp = (len + padlen) % state->extra_pad; |
| /* Check whether pad calculation below will underflow */ |
| if (tmp > state->extra_pad) |
| return SSH_ERR_INVALID_ARGUMENT; |
| pad = state->extra_pad - tmp; |
| DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)", |
| __func__, pad, len, padlen, state->extra_pad)); |
| tmp = padlen; |
| padlen += pad; |
| /* Check whether padlen calculation overflowed */ |
| if (padlen < tmp) |
| return SSH_ERR_INVALID_ARGUMENT; /* overflow */ |
| state->extra_pad = 0; |
| } |
| if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0) |
| goto out; |
| if (enc && !cipher_ctx_is_plaintext(state->send_context)) { |
| /* random padding */ |
| arc4random_buf(cp, padlen); |
| } else { |
| /* clear padding */ |
| explicit_bzero(cp, padlen); |
| } |
| /* sizeof (packet_len + pad_len + payload + padding) */ |
| len = sshbuf_len(state->outgoing_packet); |
| cp = sshbuf_mutable_ptr(state->outgoing_packet); |
| if (cp == NULL) { |
| r = SSH_ERR_INTERNAL_ERROR; |
| goto out; |
| } |
| /* packet_length includes payload, padding and padding length field */ |
| POKE_U32(cp, len - 4); |
| cp[4] = padlen; |
| DBG(debug("send: len %d (includes padlen %d, aadlen %d)", |
| len, padlen, aadlen)); |
| |
| /* compute MAC over seqnr and packet(length fields, payload, padding) */ |
| if (mac && mac->enabled && !mac->etm) { |
| if ((r = mac_compute(mac, state->p_send.seqnr, |
| sshbuf_ptr(state->outgoing_packet), len, |
| macbuf, sizeof(macbuf))) != 0) |
| goto out; |
| DBG(debug("done calc MAC out #%d", state->p_send.seqnr)); |
| } |
| /* encrypt packet and append to output buffer. */ |
| if ((r = sshbuf_reserve(state->output, |
| sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0) |
| goto out; |
| if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp, |
| sshbuf_ptr(state->outgoing_packet), |
| len - aadlen, aadlen, authlen)) != 0) |
| goto out; |
| /* append unencrypted MAC */ |
| if (mac && mac->enabled) { |
| if (mac->etm) { |
| /* EtM: compute mac over aadlen + cipher text */ |
| if ((r = mac_compute(mac, state->p_send.seqnr, |
| cp, len, macbuf, sizeof(macbuf))) != 0) |
| goto out; |
| DBG(debug("done calc MAC(EtM) out #%d", |
| state->p_send.seqnr)); |
| } |
| if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0) |
| goto out; |
| } |
| #ifdef PACKET_DEBUG |
| fprintf(stderr, "encrypted: "); |
| sshbuf_dump(state->output, stderr); |
| #endif |
| /* increment sequence number for outgoing packets */ |
| if (++state->p_send.seqnr == 0) |
| logit("outgoing seqnr wraps around"); |
| if (++state->p_send.packets == 0) |
| if (!(ssh->compat & SSH_BUG_NOREKEY)) |
| return SSH_ERR_NEED_REKEY; |
| state->p_send.blocks += len / block_size; |
| state->p_send.bytes += len; |
| sshbuf_reset(state->outgoing_packet); |
| |
| if (type == SSH2_MSG_NEWKEYS) |
| r = ssh_set_newkeys(ssh, MODE_OUT); |
| else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side) |
| r = ssh_packet_enable_delayed_compress(ssh); |
| else |
| r = 0; |
| out: |
| return r; |
| } |
| |
| /* returns non-zero if the specified packet type is usec by KEX */ |
| static int |
| ssh_packet_type_is_kex(u_char type) |
| { |
| return |
| type >= SSH2_MSG_TRANSPORT_MIN && |
| type <= SSH2_MSG_TRANSPORT_MAX && |
| type != SSH2_MSG_SERVICE_REQUEST && |
| type != SSH2_MSG_SERVICE_ACCEPT && |
| type != SSH2_MSG_EXT_INFO; |
| } |
| |
| int |
| ssh_packet_send2(struct ssh *ssh) |
| { |
| struct session_state *state = ssh->state; |
| struct packet *p; |
| u_char type; |
| int r, need_rekey; |
| |
| if (sshbuf_len(state->outgoing_packet) < 6) |
| return SSH_ERR_INTERNAL_ERROR; |
| type = sshbuf_ptr(state->outgoing_packet)[5]; |
| need_rekey = !ssh_packet_type_is_kex(type) && |
| ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet)); |
| |
| /* |
| * During rekeying we can only send key exchange messages. |
| * Queue everything else. |
| */ |
| if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) { |
| if (need_rekey) |
| debug3("%s: rekex triggered", __func__); |
| debug("enqueue packet: %u", type); |
| p = calloc(1, sizeof(*p)); |
| if (p == NULL) |
| return SSH_ERR_ALLOC_FAIL; |
| p->type = type; |
| p->payload = state->outgoing_packet; |
| TAILQ_INSERT_TAIL(&state->outgoing, p, next); |
| state->outgoing_packet = sshbuf_new(); |
| if (state->outgoing_packet == NULL) |
| return SSH_ERR_ALLOC_FAIL; |
| if (need_rekey) { |
| /* |
| * This packet triggered a rekey, so send the |
| * KEXINIT now. |
| * NB. reenters this function via kex_start_rekex(). |
| */ |
| return kex_start_rekex(ssh); |
| } |
| return 0; |
| } |
| |
| /* rekeying starts with sending KEXINIT */ |
| if (type == SSH2_MSG_KEXINIT) |
| state->rekeying = 1; |
| |
| if ((r = ssh_packet_send2_wrapped(ssh)) != 0) |
| return r; |
| |
| /* after a NEWKEYS message we can send the complete queue */ |
| if (type == SSH2_MSG_NEWKEYS) { |
| state->rekeying = 0; |
| state->rekey_time = monotime(); |
| while ((p = TAILQ_FIRST(&state->outgoing))) { |
| type = p->type; |
| /* |
| * If this packet triggers a rekex, then skip the |
| * remaining packets in the queue for now. |
| * NB. re-enters this function via kex_start_rekex. |
| */ |
| if (ssh_packet_need_rekeying(ssh, |
| sshbuf_len(p->payload))) { |
| debug3("%s: queued packet triggered rekex", |
| __func__); |
| return kex_start_rekex(ssh); |
| } |
| debug("dequeue packet: %u", type); |
| sshbuf_free(state->outgoing_packet); |
| state->outgoing_packet = p->payload; |
| TAILQ_REMOVE(&state->outgoing, p, next); |
| memset(p, 0, sizeof(*p)); |
| free(p); |
| if ((r = ssh_packet_send2_wrapped(ssh)) != 0) |
| return r; |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| * 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 |
| ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p) |
| { |
| struct session_state *state = ssh->state; |
| int len, r, ms_remain; |
| fd_set *setp; |
| char buf[8192]; |
| struct timeval timeout, start, *timeoutp = NULL; |
| |
| DBG(debug("packet_read()")); |
| |
| setp = calloc(howmany(state->connection_in + 1, |
| NFDBITS), sizeof(fd_mask)); |
| if (setp == NULL) |
| return SSH_ERR_ALLOC_FAIL; |
| |
| /* |
| * Since we are blocking, ensure that all written packets have |
| * been sent. |
| */ |
| if ((r = ssh_packet_write_wait(ssh)) != 0) |
| goto out; |
| |
| /* Stay in the loop until we have received a complete packet. */ |
| for (;;) { |
| /* Try to read a packet from the buffer. */ |
| r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p); |
| if (r != 0) |
| break; |
| if (!compat20 && ( |
| *typep == SSH_SMSG_SUCCESS |
| || *typep == SSH_SMSG_FAILURE |
| || *typep == SSH_CMSG_EOF |
| || *typep == SSH_CMSG_EXIT_CONFIRMATION)) |
| if ((r = sshpkt_get_end(ssh)) != 0) |
| break; |
| /* If we got a packet, return it. */ |
| if (*typep != SSH_MSG_NONE) |
| break; |
| /* |
| * Otherwise, wait for some data to arrive, add it to the |
| * buffer, and try again. |
| */ |
| memset(setp, 0, howmany(state->connection_in + 1, |
| NFDBITS) * sizeof(fd_mask)); |
| FD_SET(state->connection_in, setp); |
| |
| if (state->packet_timeout_ms > 0) { |
| ms_remain = state->packet_timeout_ms; |
| timeoutp = &timeout; |
| } |
| /* Wait for some data to arrive. */ |
| for (;;) { |
| if (state->packet_timeout_ms != -1) { |
| ms_to_timeval(&timeout, ms_remain); |
| gettimeofday(&start, NULL); |
| } |
| if ((r = select(state->connection_in + 1, setp, |
| NULL, NULL, timeoutp)) >= 0) |
| break; |
| if (errno != EAGAIN && errno != EINTR && |
| errno != EWOULDBLOCK) |
| break; |
| if (state->packet_timeout_ms == -1) |
| continue; |
| ms_subtract_diff(&start, &ms_remain); |
| if (ms_remain <= 0) { |
| r = 0; |
| break; |
| } |
| } |
| if (r == 0) |
| return SSH_ERR_CONN_TIMEOUT; |
| /* Read data from the socket. */ |
| len = read(state->connection_in, buf, sizeof(buf)); |
| if (len == 0) { |
| r = SSH_ERR_CONN_CLOSED; |
| goto out; |
| } |
| if (len < 0) { |
| r = SSH_ERR_SYSTEM_ERROR; |
| goto out; |
| } |
| |
| /* Append it to the buffer. */ |
| if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0) |
| goto out; |
| } |
| out: |
| free(setp); |
| return r; |
| } |
| |
| int |
| ssh_packet_read(struct ssh *ssh) |
| { |
| u_char type; |
| int r; |
| |
| if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0) |
| fatal("%s: %s", __func__, ssh_err(r)); |
| return type; |
| } |
| |
| /* |
| * 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. |
| */ |
| |
| int |
| ssh_packet_read_expect(struct ssh *ssh, u_int expected_type) |
| { |
| int r; |
| u_char type; |
| |
| if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0) |
| return r; |
| if (type != expected_type) { |
| if ((r = sshpkt_disconnect(ssh, |
| "Protocol error: expected packet type %d, got %d", |
| expected_type, type)) != 0) |
| return r; |
| return SSH_ERR_PROTOCOL_ERROR; |
| } |
| return 0; |
| } |
| |
| /* 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. |
| */ |
| |
| int |
| ssh_packet_read_poll1(struct ssh *ssh, u_char *typep) |
| { |
| struct session_state *state = ssh->state; |
| u_int len, padded_len; |
| const char *emsg; |
| const u_char *cp; |
| u_char *p; |
| u_int checksum, stored_checksum; |
| int r; |
| |
| *typep = SSH_MSG_NONE; |
| |
| /* Check if input size is less than minimum packet size. */ |
| if (sshbuf_len(state->input) < 4 + 8) |
| return 0; |
| /* Get length of incoming packet. */ |
| len = PEEK_U32(sshbuf_ptr(state->input)); |
| if (len < 1 + 2 + 2 || len > 256 * 1024) { |
| if ((r = sshpkt_disconnect(ssh, "Bad packet length %u", |
| len)) != 0) |
| return r; |
| return SSH_ERR_CONN_CORRUPT; |
| } |
| padded_len = (len + 8) & ~7; |
| |
| /* Check if the packet has been entirely received. */ |
| if (sshbuf_len(state->input) < 4 + padded_len) |
| return 0; |
| |
| /* The entire packet is in buffer. */ |
| |
| /* Consume packet length. */ |
| if ((r = sshbuf_consume(state->input, 4)) != 0) |
| goto out; |
| |
| /* |
| * Cryptographic attack detector for ssh |
| * (C)1998 CORE-SDI, Buenos Aires Argentina |
| * Ariel Futoransky(futo@core-sdi.com) |
| */ |
| if (!cipher_ctx_is_plaintext(state->receive_context)) { |
| emsg = NULL; |
| switch (detect_attack(&state->deattack, |
| sshbuf_ptr(state->input), padded_len)) { |
| case DEATTACK_OK: |
| break; |
| case DEATTACK_DETECTED: |
| emsg = "crc32 compensation attack detected"; |
| break; |
| case DEATTACK_DOS_DETECTED: |
| emsg = "deattack denial of service detected"; |
| break; |
| default: |
| emsg = "deattack error"; |
| break; |
| } |
| if (emsg != NULL) { |
| error("%s", emsg); |
| if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 || |
| (r = ssh_packet_write_wait(ssh)) != 0) |
| return r; |
| return SSH_ERR_CONN_CORRUPT; |
| } |
| } |
| |
| /* Decrypt data to incoming_packet. */ |
| sshbuf_reset(state->incoming_packet); |
| if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0) |
| goto out; |
| if ((r = cipher_crypt(state->receive_context, 0, p, |
| sshbuf_ptr(state->input), padded_len, 0, 0)) != 0) |
| goto out; |
| |
| if ((r = sshbuf_consume(state->input, padded_len)) != 0) |
| goto out; |
| |
| #ifdef PACKET_DEBUG |
| fprintf(stderr, "read_poll plain: "); |
| sshbuf_dump(state->incoming_packet, stderr); |
| #endif |
| |
| /* Compute packet checksum. */ |
| checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet), |
| sshbuf_len(state->incoming_packet) - 4); |
| |
| /* Skip padding. */ |
| if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0) |
| goto out; |
| |
| /* Test check bytes. */ |
| if (len != sshbuf_len(state->incoming_packet)) { |
| error("%s: len %d != sshbuf_len %zd", __func__, |
| len, sshbuf_len(state->incoming_packet)); |
| if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 || |
| (r = ssh_packet_write_wait(ssh)) != 0) |
| return r; |
| return SSH_ERR_CONN_CORRUPT; |
| } |
| |
| cp = sshbuf_ptr(state->incoming_packet) + len - 4; |
| stored_checksum = PEEK_U32(cp); |
| if (checksum != stored_checksum) { |
| error("Corrupted check bytes on input"); |
| if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 || |
| (r = ssh_packet_write_wait(ssh)) != 0) |
| return r; |
| return SSH_ERR_CONN_CORRUPT; |
| } |
| if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0) |
| goto out; |
| |
| if (state->packet_compression) { |
| sshbuf_reset(state->compression_buffer); |
| if ((r = uncompress_buffer(ssh, state->incoming_packet, |
| state->compression_buffer)) != 0) |
| goto out; |
| sshbuf_reset(state->incoming_packet); |
| if ((r = sshbuf_putb(state->incoming_packet, |
| state->compression_buffer)) != 0) |
| goto out; |
| } |
| state->p_read.packets++; |
| state->p_read.bytes += padded_len + 4; |
| if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0) |
| goto out; |
| if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) { |
| error("Invalid ssh1 packet type: %d", *typep); |
| if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 || |
| (r = ssh_packet_write_wait(ssh)) != 0) |
| return r; |
| return SSH_ERR_PROTOCOL_ERROR; |
| } |
| r = 0; |
| out: |
| return r; |
| } |
| |
| int |
| ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p) |
| { |
| struct session_state *state = ssh->state; |
| u_int padlen, need; |
| u_char *cp; |
| u_int maclen, aadlen = 0, authlen = 0, block_size; |
| struct sshenc *enc = NULL; |
| struct sshmac *mac = NULL; |
| struct sshcomp *comp = NULL; |
| int r; |
| |
| *typep = SSH_MSG_NONE; |
| |
| if (state->packet_discard) |
| return 0; |
| |
| if (state->newkeys[MODE_IN] != NULL) { |
| enc = &state->newkeys[MODE_IN]->enc; |
| mac = &state->newkeys[MODE_IN]->mac; |
| comp = &state->newkeys[MODE_IN]->comp; |
| /* disable mac for authenticated encryption */ |
| if ((authlen = cipher_authlen(enc->cipher)) != 0) |
| mac = NULL; |
| } |
| maclen = mac && mac->enabled ? mac->mac_len : 0; |
| block_size = enc ? enc->block_size : 8; |
| aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0; |
| |
| if (aadlen && state->packlen == 0) { |
| if (cipher_get_length(state->receive_context, |
| &state->packlen, state->p_read.seqnr, |
| sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0) |
| return 0; |
| if (state->packlen < 1 + 4 || |
| state->packlen > PACKET_MAX_SIZE) { |
| #ifdef PACKET_DEBUG |
| sshbuf_dump(state->input, stderr); |
| #endif |
| logit("Bad packet length %u.", state->packlen); |
| if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0) |
| return r; |
| return SSH_ERR_CONN_CORRUPT; |
| } |
| sshbuf_reset(state->incoming_packet); |
| } else if (state->packlen == 0) { |
| /* |
| * check if input size is less than the cipher block size, |
| * decrypt first block and extract length of incoming packet |
| */ |
| if (sshbuf_len(state->input) < block_size) |
| return 0; |
| sshbuf_reset(state->incoming_packet); |
| if ((r = sshbuf_reserve(state->incoming_packet, block_size, |
| &cp)) != 0) |
| goto out; |
| if ((r = cipher_crypt(state->receive_context, |
| state->p_send.seqnr, cp, sshbuf_ptr(state->input), |
| block_size, 0, 0)) != 0) |
| goto out; |
| state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet)); |
| if (state->packlen < 1 + 4 || |
| state->packlen > PACKET_MAX_SIZE) { |
| #ifdef PACKET_DEBUG |
| fprintf(stderr, "input: \n"); |
| sshbuf_dump(state->input, stderr); |
| fprintf(stderr, "incoming_packet: \n"); |
| sshbuf_dump(state->incoming_packet, stderr); |
| #endif |
| logit("Bad packet length %u.", state->packlen); |
| return ssh_packet_start_discard(ssh, enc, mac, 0, |
| PACKET_MAX_SIZE); |
| } |
| if ((r = sshbuf_consume(state->input, block_size)) != 0) |
| goto out; |
| } |
| DBG(debug("input: packet len %u", state->packlen+4)); |
| |
| if (aadlen) { |
| /* only the payload is encrypted */ |
| need = state->packlen; |
| } else { |
| /* |
| * the payload size and the payload are encrypted, but we |
| * have a partial packet of block_size bytes |
| */ |
| need = 4 + state->packlen - block_size; |
| } |
| DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d," |
| " aadlen %d", block_size, need, maclen, authlen, aadlen)); |
| if (need % block_size != 0) { |
| logit("padding error: need %d block %d mod %d", |
| need, block_size, need % block_size); |
| return ssh_packet_start_discard(ssh, enc, mac, 0, |
| PACKET_MAX_SIZE - block_size); |
| } |
| /* |
| * check if the entire packet has been received and |
| * decrypt into incoming_packet: |
| * 'aadlen' bytes are unencrypted, but authenticated. |
| * 'need' bytes are encrypted, followed by either |
| * 'authlen' bytes of authentication tag or |
| * 'maclen' bytes of message authentication code. |
| */ |
| if (sshbuf_len(state->input) < aadlen + need + authlen + maclen) |
| return 0; /* packet is incomplete */ |
| #ifdef PACKET_DEBUG |
| fprintf(stderr, "read_poll enc/full: "); |
| sshbuf_dump(state->input, stderr); |
| #endif |
| /* EtM: check mac over encrypted input */ |
| if (mac && mac->enabled && mac->etm) { |
| if ((r = mac_check(mac, state->p_read.seqnr, |
| sshbuf_ptr(state->input), aadlen + need, |
| sshbuf_ptr(state->input) + aadlen + need + authlen, |
| maclen)) != 0) { |
| if (r == SSH_ERR_MAC_INVALID) |
| logit("Corrupted MAC on input."); |
| goto out; |
| } |
| } |
| if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need, |
| &cp)) != 0) |
| goto out; |
| if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp, |
| sshbuf_ptr(state->input), need, aadlen, authlen)) != 0) |
| goto out; |
| if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0) |
| goto out; |
| if (mac && mac->enabled) { |
| /* Not EtM: check MAC over cleartext */ |
| if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr, |
| sshbuf_ptr(state->incoming_packet), |
| sshbuf_len(state->incoming_packet), |
| sshbuf_ptr(state->input), maclen)) != 0) { |
| if (r != SSH_ERR_MAC_INVALID) |
| goto out; |
| logit("Corrupted MAC on input."); |
| if (need > PACKET_MAX_SIZE) |
| return SSH_ERR_INTERNAL_ERROR; |
| return ssh_packet_start_discard(ssh, enc, mac, |
| sshbuf_len(state->incoming_packet), |
| PACKET_MAX_SIZE - need); |
| } |
| /* Remove MAC from input buffer */ |
| DBG(debug("MAC #%d ok", state->p_read.seqnr)); |
| if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0) |
| goto out; |
| } |
| if (seqnr_p != NULL) |
| *seqnr_p = state->p_read.seqnr; |
| if (++state->p_read.seqnr == 0) |
| logit("incoming seqnr wraps around"); |
| if (++state->p_read.packets == 0) |
| if (!(ssh->compat & SSH_BUG_NOREKEY)) |
| return SSH_ERR_NEED_REKEY; |
| state->p_read.blocks += (state->packlen + 4) / block_size; |
| state->p_read.bytes += state->packlen + 4; |
| |
| /* get padlen */ |
| padlen = sshbuf_ptr(state->incoming_packet)[4]; |
| DBG(debug("input: padlen %d", padlen)); |
| if (padlen < 4) { |
| if ((r = sshpkt_disconnect(ssh, |
| "Corrupted padlen %d on input.", padlen)) != 0 || |
| (r = ssh_packet_write_wait(ssh)) != 0) |
| return r; |
| return SSH_ERR_CONN_CORRUPT; |
| } |
| |
| /* skip packet size + padlen, discard padding */ |
| if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 || |
| ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0)) |
| goto out; |
| |
| DBG(debug("input: len before de-compress %zd", |
| sshbuf_len(state->incoming_packet))); |
| if (comp && comp->enabled) { |
| sshbuf_reset(state->compression_buffer); |
| if ((r = uncompress_buffer(ssh, state->incoming_packet, |
| state->compression_buffer)) != 0) |
| goto out; |
| sshbuf_reset(state->incoming_packet); |
| if ((r = sshbuf_putb(state->incoming_packet, |
| state->compression_buffer)) != 0) |
| goto out; |
| DBG(debug("input: len after de-compress %zd", |
| sshbuf_len(state->incoming_packet))); |
| } |
| /* |
| * get packet type, implies consume. |
| * return length of payload (without type field) |
| */ |
| if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0) |
| goto out; |
| if (ssh_packet_log_type(*typep)) |
| debug3("receive packet: type %u", *typep); |
| if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) { |
| if ((r = sshpkt_disconnect(ssh, |
| "Invalid ssh2 packet type: %d", *typep)) != 0 || |
| (r = ssh_packet_write_wait(ssh)) != 0) |
| return r; |
| return SSH_ERR_PROTOCOL_ERROR; |
| } |
| if (*typep == SSH2_MSG_NEWKEYS) |
| r = ssh_set_newkeys(ssh, MODE_IN); |
| else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side) |
| r = ssh_packet_enable_delayed_compress(ssh); |
| else |
| r = 0; |
| #ifdef PACKET_DEBUG |
| fprintf(stderr, "read/plain[%d]:\r\n", *typep); |
| sshbuf_dump(state->incoming_packet, stderr); |
| #endif |
| /* reset for next packet */ |
| state->packlen = 0; |
| |
| /* do we need to rekey? */ |
| if (ssh_packet_need_rekeying(ssh, 0)) { |
| debug3("%s: rekex triggered", __func__); |
| if ((r = kex_start_rekex(ssh)) != 0) |
| return r; |
| } |
| out: |
| return r; |
| } |
| |
| int |
| ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p) |
| { |
| struct session_state *state = ssh->state; |
| u_int reason, seqnr; |
| int r; |
| u_char *msg; |
| |
| for (;;) { |
| msg = NULL; |
| if (compat20) { |
| r = ssh_packet_read_poll2(ssh, typep, seqnr_p); |
| if (r != 0) |
| return r; |
| if (*typep) { |
| state->keep_alive_timeouts = 0; |
| DBG(debug("received packet type %d", *typep)); |
| } |
| switch (*typep) { |
| case SSH2_MSG_IGNORE: |
| debug3("Received SSH2_MSG_IGNORE"); |
| break; |
| case SSH2_MSG_DEBUG: |
| if ((r = sshpkt_get_u8(ssh, NULL)) != 0 || |
| (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 || |
| (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) { |
| free(msg); |
| return r; |
| } |
| debug("Remote: %.900s", msg); |
| free(msg); |
| break; |
| case SSH2_MSG_DISCONNECT: |
| if ((r = sshpkt_get_u32(ssh, &reason)) != 0 || |
| (r = sshpkt_get_string(ssh, &msg, NULL)) != 0) |
| return r; |
| /* Ignore normal client exit notifications */ |
| do_log2(ssh->state->server_side && |
| reason == SSH2_DISCONNECT_BY_APPLICATION ? |
| SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR, |
| "Received disconnect from %s port %d:" |
| "%u: %.400s", ssh_remote_ipaddr(ssh), |
| ssh_remote_port(ssh), reason, msg); |
| free(msg); |
| return SSH_ERR_DISCONNECTED; |
| case SSH2_MSG_UNIMPLEMENTED: |
| if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0) |
| return r; |
| debug("Received SSH2_MSG_UNIMPLEMENTED for %u", |
| seqnr); |
| break; |
| default: |
| return 0; |
| } |
| } else { |
| r = ssh_packet_read_poll1(ssh, typep); |
| switch (*typep) { |
| case SSH_MSG_NONE: |
| return SSH_MSG_NONE; |
| case SSH_MSG_IGNORE: |
| break; |
| case SSH_MSG_DEBUG: |
| if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0) |
| return r; |
| debug("Remote: %.900s", msg); |
| free(msg); |
| break; |
| case SSH_MSG_DISCONNECT: |
| if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0) |
| return r; |
| error("Received disconnect from %s port %d: " |
| "%.400s", ssh_remote_ipaddr(ssh), |
| ssh_remote_port(ssh), msg); |
| free(msg); |
| return SSH_ERR_DISCONNECTED; |
| default: |
| DBG(debug("received packet type %d", *typep)); |
| return 0; |
| } |
| } |
| } |
| } |
| |
| /* |
| * Buffers the given amount of input characters. This is intended to be used |
| * together with packet_read_poll. |
| */ |
| |
| int |
| ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len) |
| { |
| struct session_state *state = ssh->state; |
| int r; |
| |
| if (state->packet_discard) { |
| state->keep_alive_timeouts = 0; /* ?? */ |
| if (len >= state->packet_discard) { |
| if ((r = ssh_packet_stop_discard(ssh)) != 0) |
| return r; |
| } |
| state->packet_discard -= len; |
| return 0; |
| } |
| if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0) |
| return r; |
| |
| return 0; |
| } |
| |
| int |
| ssh_packet_remaining(struct ssh *ssh) |
| { |
| return sshbuf_len(ssh->state->incoming_packet); |
| } |
| |
| /* |
| * 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 ssh_packet_write_wait. |
| */ |
| void |
| ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...) |
| { |
| char buf[1024]; |
| va_list args; |
| int r; |
| |
| if (compat20 && (ssh->compat & SSH_BUG_DEBUG)) |
| return; |
| |
| va_start(args, fmt); |
| vsnprintf(buf, sizeof(buf), fmt, args); |
| va_end(args); |
| |
| if (compat20) { |
| if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 || |
| (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */ |
| (r = sshpkt_put_cstring(ssh, buf)) != 0 || |
| (r = sshpkt_put_cstring(ssh, "")) != 0 || |
| (r = sshpkt_send(ssh)) != 0) |
| fatal("%s: %s", __func__, ssh_err(r)); |
| } else { |
| if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 || |
| (r = sshpkt_put_cstring(ssh, buf)) != 0 || |
| (r = sshpkt_send(ssh)) != 0) |
| fatal("%s: %s", __func__, ssh_err(r)); |
| } |
| if ((r = ssh_packet_write_wait(ssh)) != 0) |
| fatal("%s: %s", __func__, ssh_err(r)); |
| } |
| |
| /* |
| * Pretty-print connection-terminating errors and exit. |
| */ |
| void |
| sshpkt_fatal(struct ssh *ssh, const char *tag, int r) |
| { |
| switch (r) { |
| case SSH_ERR_CONN_CLOSED: |
| logdie("Connection closed by %.200s port %d", |
| ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); |
| case SSH_ERR_CONN_TIMEOUT: |
| logdie("Connection %s %.200s port %d timed out", |
| ssh->state->server_side ? "from" : "to", |
| ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); |
| case SSH_ERR_DISCONNECTED: |
| logdie("Disconnected from %.200s port %d", |
| ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); |
| case SSH_ERR_SYSTEM_ERROR: |
| if (errno == ECONNRESET) |
| logdie("Connection reset by %.200s port %d", |
| ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); |
| /* FALLTHROUGH */ |
| case SSH_ERR_NO_CIPHER_ALG_MATCH: |
| case SSH_ERR_NO_MAC_ALG_MATCH: |
| case SSH_ERR_NO_COMPRESS_ALG_MATCH: |
| case SSH_ERR_NO_KEX_ALG_MATCH: |
| case SSH_ERR_NO_HOSTKEY_ALG_MATCH: |
| if (ssh && ssh->kex && ssh->kex->failed_choice) { |
| logdie("Unable to negotiate with %.200s port %d: %s. " |
| "Their offer: %s", ssh_remote_ipaddr(ssh), |
| ssh_remote_port(ssh), ssh_err(r), |
| ssh->kex->failed_choice); |
| } |
| /* FALLTHROUGH */ |
| default: |
| logdie("%s%sConnection %s %.200s port %d: %s", |
| tag != NULL ? tag : "", tag != NULL ? ": " : "", |
| ssh->state->server_side ? "from" : "to", |
| ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), ssh_err(r)); |
| } |
| } |
| |
| /* |
| * 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 |
| ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...) |
| { |
| char buf[1024]; |
| va_list args; |
| static int disconnecting = 0; |
| int r; |
| |
| 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 ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0) |
| sshpkt_fatal(ssh, __func__, r); |
| |
| if ((r = ssh_packet_write_wait(ssh)) != 0) |
| sshpkt_fatal(ssh, __func__, r); |
| |
| /* Close the connection. */ |
| ssh_packet_close(ssh); |
| cleanup_exit(255); |
| } |
| |
| /* |
| * Checks if there is any buffered output, and tries to write some of |
| * the output. |
| */ |
| int |
| ssh_packet_write_poll(struct ssh *ssh) |
| { |
| struct session_state *state = ssh->state; |
| int len = sshbuf_len(state->output); |
| int r; |
| |
| if (len > 0) { |
| len = write(state->connection_out, |
| sshbuf_ptr(state->output), len); |
| if (len == -1) { |
| if (errno == EINTR || errno == EAGAIN || |
| errno == EWOULDBLOCK) |
| return 0; |
| return SSH_ERR_SYSTEM_ERROR; |
| } |
| if (len == 0) |
| return SSH_ERR_CONN_CLOSED; |
| if ((r = sshbuf_consume(state->output, len)) != 0) |
| return r; |
| } |
| return 0; |
| } |
| |
| /* |
| * Calls packet_write_poll repeatedly until all pending output data has been |
| * written. |
| */ |
| int |
| ssh_packet_write_wait(struct ssh *ssh) |
| { |
| fd_set *setp; |
| int ret, r, ms_remain = 0; |
| struct timeval start, timeout, *timeoutp = NULL; |
| struct session_state *state = ssh->state; |
| |
| setp = calloc(howmany(state->connection_out + 1, |
| NFDBITS), sizeof(fd_mask)); |
| if (setp == NULL) |
| return SSH_ERR_ALLOC_FAIL; |
| if ((r = ssh_packet_write_poll(ssh)) != 0) { |
| free(setp); |
| return r; |
| } |
| while (ssh_packet_have_data_to_write(ssh)) { |
| memset(setp, 0, howmany(state->connection_out + 1, |
| NFDBITS) * sizeof(fd_mask)); |
| FD_SET(state->connection_out, setp); |
| |
| if (state->packet_timeout_ms > 0) { |
| ms_remain = state->packet_timeout_ms; |
| timeoutp = &timeout; |
| } |
| for (;;) { |
| if (state->packet_timeout_ms != -1) { |
| ms_to_timeval(&timeout, ms_remain); |
| gettimeofday(&start, NULL); |
| } |
| if ((ret = select(state->connection_out + 1, |
| NULL, setp, NULL, timeoutp)) >= 0) |
| break; |
| if (errno != EAGAIN && errno != EINTR && |
| errno != EWOULDBLOCK) |
| break; |
| if (state->packet_timeout_ms == -1) |
| continue; |
| ms_subtract_diff(&start, &ms_remain); |
| if (ms_remain <= 0) { |
| ret = 0; |
| break; |
| } |
| } |
| if (ret == 0) { |
| free(setp); |
| return SSH_ERR_CONN_TIMEOUT; |
| } |
| if ((r = ssh_packet_write_poll(ssh)) != 0) { |
| free(setp); |
| return r; |
| } |
| } |
| free(setp); |
| return 0; |
| } |
| |
| /* Returns true if there is buffered data to write to the connection. */ |
| |
| int |
| ssh_packet_have_data_to_write(struct ssh *ssh) |
| { |
| return sshbuf_len(ssh->state->output) != 0; |
| } |
| |
| /* Returns true if there is not too much data to write to the connection. */ |
| |
| int |
| ssh_packet_not_very_much_data_to_write(struct ssh *ssh) |
| { |
| if (ssh->state->interactive_mode) |
| return sshbuf_len(ssh->state->output) < 16384; |
| else |
| return sshbuf_len(ssh->state->output) < 128 * 1024; |
| } |
| |
| void |
| ssh_packet_set_tos(struct ssh *ssh, int tos) |
| { |
| #ifndef IP_TOS_IS_BROKEN |
| if (!ssh_packet_connection_is_on_socket(ssh)) |
| return; |
| switch (ssh_packet_connection_af(ssh)) { |
| # ifdef IP_TOS |
| case AF_INET: |
| debug3("%s: set IP_TOS 0x%02x", __func__, tos); |
| if (setsockopt(ssh->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(ssh->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 |
| ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk) |
| { |
| struct session_state *state = ssh->state; |
| |
| if (state->set_interactive_called) |
| return; |
| state->set_interactive_called = 1; |
| |
| /* Record that we are in interactive mode. */ |
| state->interactive_mode = interactive; |
| |
| /* Only set socket options if using a socket. */ |
| if (!ssh_packet_connection_is_on_socket(ssh)) |
| return; |
| set_nodelay(state->connection_in); |
| ssh_packet_set_tos(ssh, interactive ? qos_interactive : |
| qos_bulk); |
| } |
| |
| /* Returns true if the current connection is interactive. */ |
| |
| int |
| ssh_packet_is_interactive(struct ssh *ssh) |
| { |
| return ssh->state->interactive_mode; |
| } |
| |
| int |
| ssh_packet_set_maxsize(struct ssh *ssh, u_int s) |
| { |
| struct session_state *state = ssh->state; |
| |
| if (state->set_maxsize_called) { |
| logit("packet_set_maxsize: called twice: old %d new %d", |
| state->max_packet_size, s); |
| return -1; |
| } |
| if (s < 4 * 1024 || s > 1024 * 1024) { |
| logit("packet_set_maxsize: bad size %d", s); |
| return -1; |
| } |
| state->set_maxsize_called = 1; |
| debug("packet_set_maxsize: setting to %d", s); |
| state->max_packet_size = s; |
| return s; |
| } |
| |
| int |
| ssh_packet_inc_alive_timeouts(struct ssh *ssh) |
| { |
| return ++ssh->state->keep_alive_timeouts; |
| } |
| |
| void |
| ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka) |
| { |
| ssh->state->keep_alive_timeouts = ka; |
| } |
| |
| u_int |
| ssh_packet_get_maxsize(struct ssh *ssh) |
| { |
| return ssh->state->max_packet_size; |
| } |
| |
| /* |
| * 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 |
| ssh_packet_send_ignore(struct ssh *ssh, int nbytes) |
| { |
| u_int32_t rnd = 0; |
| int r, i; |
| |
| if ((r = sshpkt_start(ssh, compat20 ? |
| SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 || |
| (r = sshpkt_put_u32(ssh, nbytes)) != 0) |
| fatal("%s: %s", __func__, ssh_err(r)); |
| for (i = 0; i < nbytes; i++) { |
| if (i % 4 == 0) |
| rnd = arc4random(); |
| if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0) |
| fatal("%s: %s", __func__, ssh_err(r)); |
| rnd >>= 8; |
| } |
| } |
| |
| void |
| ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, time_t seconds) |
| { |
| debug3("rekey after %llu bytes, %d seconds", (unsigned long long)bytes, |
| (int)seconds); |
| ssh->state->rekey_limit = bytes; |
| ssh->state->rekey_interval = seconds; |
| } |
| |
| time_t |
| ssh_packet_get_rekey_timeout(struct ssh *ssh) |
| { |
| time_t seconds; |
| |
| seconds = ssh->state->rekey_time + ssh->state->rekey_interval - |
| monotime(); |
| return (seconds <= 0 ? 1 : seconds); |
| } |
| |
| void |
| ssh_packet_set_server(struct ssh *ssh) |
| { |
| ssh->state->server_side = 1; |
| } |
| |
| void |
| ssh_packet_set_authenticated(struct ssh *ssh) |
| { |
| ssh->state->after_authentication = 1; |
| } |
| |
| void * |
| ssh_packet_get_input(struct ssh *ssh) |
| { |
| return (void *)ssh->state->input; |
| } |
| |
| void * |
| ssh_packet_get_output(struct ssh *ssh) |
| { |
| return (void *)ssh->state->output; |
| } |
| |
| /* Reset after_authentication and reset compression in post-auth privsep */ |
| static int |
| ssh_packet_set_postauth(struct ssh *ssh) |
| { |
| struct sshcomp *comp; |
| int r, mode; |
| |
| debug("%s: called", __func__); |
| /* This was set in net child, but is not visible in user child */ |
| ssh->state->after_authentication = 1; |
| ssh->state->rekeying = 0; |
| for (mode = 0; mode < MODE_MAX; mode++) { |
| if (ssh->state->newkeys[mode] == NULL) |
| continue; |
| comp = &ssh->state->newkeys[mode]->comp; |
| if (comp && comp->enabled && |
| (r = ssh_packet_init_compression(ssh)) != 0) |
| return r; |
| } |
| return 0; |
| } |
| |
| /* Packet state (de-)serialization for privsep */ |
| |
| /* turn kex into a blob for packet state serialization */ |
| static int |
| kex_to_blob(struct sshbuf *m, struct kex *kex) |
| { |
| int r; |
| |
| if ((r = sshbuf_put_string(m, kex->session_id, |
| kex->session_id_len)) != 0 || |
| (r = sshbuf_put_u32(m, kex->we_need)) != 0 || |
| (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 || |
| (r = sshbuf_put_u32(m, kex->kex_type)) != 0 || |
| (r = sshbuf_put_stringb(m, kex->my)) != 0 || |
| (r = sshbuf_put_stringb(m, kex->peer)) != 0 || |
| (r = sshbuf_put_u32(m, kex->flags)) != 0 || |
| (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 || |
| (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0) |
| return r; |
| return 0; |
| } |
| |
| /* turn key exchange results into a blob for packet state serialization */ |
| static int |
| newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode) |
| { |
| struct sshbuf *b; |
| struct sshcipher_ctx *cc; |
| struct sshcomp *comp; |
| struct sshenc *enc; |
| struct sshmac *mac; |
| struct newkeys *newkey; |
| int r; |
| |
| if ((newkey = ssh->state->newkeys[mode]) == NULL) |
| return SSH_ERR_INTERNAL_ERROR; |
| enc = &newkey->enc; |
| mac = &newkey->mac; |
| comp = &newkey->comp; |
| cc = (mode == MODE_OUT) ? ssh->state->send_context : |
| ssh->state->receive_context; |
| if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0) |
| return r; |
| if ((b = sshbuf_new()) == NULL) |
| return SSH_ERR_ALLOC_FAIL; |
| /* The cipher struct is constant and shared, you export pointer */ |
| if ((r = sshbuf_put_cstring(b, enc->name)) != 0 || |
| (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 || |
| (r = sshbuf_put_u32(b, enc->enabled)) != 0 || |
| (r = sshbuf_put_u32(b, enc->block_size)) != 0 || |
| (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 || |
| (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0) |
| goto out; |
| if (cipher_authlen(enc->cipher) == 0) { |
| if ((r = sshbuf_put_cstring(b, mac->name)) != 0 || |
| (r = sshbuf_put_u32(b, mac->enabled)) != 0 || |
| (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0) |
| goto out; |
| } |
| if ((r = sshbuf_put_u32(b, comp->type)) != 0 || |
| (r = sshbuf_put_u32(b, comp->enabled)) != 0 || |
| (r = sshbuf_put_cstring(b, comp->name)) != 0) |
| goto out; |
| r = sshbuf_put_stringb(m, b); |
| out: |
| sshbuf_free(b); |
| return r; |
| } |
| |
| /* serialize packet state into a blob */ |
| int |
| ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m) |
| { |
| struct session_state *state = ssh->state; |
| u_char *p; |
| size_t slen, rlen; |
| int r, ssh1cipher; |
| |
| if (!compat20) { |
| ssh1cipher = cipher_ctx_get_number(state->receive_context); |
| slen = cipher_get_keyiv_len(state->send_context); |
| rlen = cipher_get_keyiv_len(state->receive_context); |
| if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 || |
| (r = sshbuf_put_u32(m, ssh1cipher)) != 0 || |
| (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 || |
| (r = sshbuf_put_u32(m, slen)) != 0 || |
| (r = sshbuf_reserve(m, slen, &p)) != 0 || |
| (r = cipher_get_keyiv(state->send_context, p, slen)) != 0 || |
| (r = sshbuf_put_u32(m, rlen)) != 0 || |
| (r = sshbuf_reserve(m, rlen, &p)) != 0 || |
| (r = cipher_get_keyiv(state->receive_context, p, rlen)) != 0) |
| return r; |
| } else { |
| if ((r = kex_to_blob(m, ssh->kex)) != 0 || |
| (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 || |
| (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 || |
| (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 || |
| (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 || |
| (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 || |
| (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 || |
| (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 || |
| (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 || |
| (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 || |
| (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 || |
| (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 || |
| (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0) |
| return r; |
| } |
| |
| slen = cipher_get_keycontext(state->send_context, NULL); |
| rlen = cipher_get_keycontext(state->receive_context, NULL); |
| if ((r = sshbuf_put_u32(m, slen)) != 0 || |
| (r = sshbuf_reserve(m, slen, &p)) != 0) |
| return r; |
| if (cipher_get_keycontext(state->send_context, p) != (int)slen) |
| return SSH_ERR_INTERNAL_ERROR; |
| if ((r = sshbuf_put_u32(m, rlen)) != 0 || |
| (r = sshbuf_reserve(m, rlen, &p)) != 0) |
| return r; |
| if (cipher_get_keycontext(state->receive_context, p) != (int)rlen) |
| return SSH_ERR_INTERNAL_ERROR; |
| |
| if ((r = ssh_packet_get_compress_state(m, ssh)) != 0 || |
| (r = sshbuf_put_stringb(m, state->input)) != 0 || |
| (r = sshbuf_put_stringb(m, state->output)) != 0) |
| return r; |
| |
| return 0; |
| } |
| |
| /* restore key exchange results from blob for packet state de-serialization */ |
| static int |
| newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode) |
| { |
| struct sshbuf *b = NULL; |
| struct sshcomp *comp; |
| struct sshenc *enc; |
| struct sshmac *mac; |
| struct newkeys *newkey = NULL; |
| size_t keylen, ivlen, maclen; |
| int r; |
| |
| if ((newkey = calloc(1, sizeof(*newkey))) == NULL) { |
| r = SSH_ERR_ALLOC_FAIL; |
| goto out; |
| } |
| if ((r = sshbuf_froms(m, &b)) != 0) |
| goto out; |
| #ifdef DEBUG_PK |
| sshbuf_dump(b, stderr); |
| #endif |
| enc = &newkey->enc; |
| mac = &newkey->mac; |
| comp = &newkey->comp; |
| |
| if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 || |
| (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 || |
| (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 || |
| (r = sshbuf_get_u32(b, &enc->block_size)) != 0 || |
| (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 || |
| (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0) |
| goto out; |
| if (cipher_authlen(enc->cipher) == 0) { |
| if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0) |
| goto out; |
| if ((r = mac_setup(mac, mac->name)) != 0) |
| goto out; |
| if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 || |
| (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0) |
| goto out; |
| if (maclen > mac->key_len) { |
| r = SSH_ERR_INVALID_FORMAT; |
| goto out; |
| } |
| mac->key_len = maclen; |
| } |
| if ((r = sshbuf_get_u32(b, &comp->type)) != 0 || |
| (r = sshbuf_get_u32(b, (u_int *)&comp->enabled)) != 0 || |
| (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0) |
| goto out; |
| if (enc->name == NULL || |
| cipher_by_name(enc->name) != enc->cipher) { |
| r = SSH_ERR_INVALID_FORMAT; |
| goto out; |
| } |
| if (sshbuf_len(b) != 0) { |
| r = SSH_ERR_INVALID_FORMAT; |
| goto out; |
| } |
| enc->key_len = keylen; |
| enc->iv_len = ivlen; |
| ssh->kex->newkeys[mode] = newkey; |
| newkey = NULL; |
| r = 0; |
| out: |
| free(newkey); |
| sshbuf_free(b); |
| return r; |
| } |
| |
| /* restore kex from blob for packet state de-serialization */ |
| static int |
| kex_from_blob(struct sshbuf *m, struct kex **kexp) |
| { |
| struct kex *kex; |
| int r; |
| |
| if ((kex = calloc(1, sizeof(struct kex))) == NULL || |
| (kex->my = sshbuf_new()) == NULL || |
| (kex->peer = sshbuf_new()) == NULL) { |
| r = SSH_ERR_ALLOC_FAIL; |
| goto out; |
| } |
| if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 || |
| (r = sshbuf_get_u32(m, &kex->we_need)) != 0 || |
| (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 || |
| (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 || |
| (r = sshbuf_get_stringb(m, kex->my)) != 0 || |
| (r = sshbuf_get_stringb(m, kex->peer)) != 0 || |
| (r = sshbuf_get_u32(m, &kex->flags)) != 0 || |
| (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 || |
| (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0) |
| goto out; |
| kex->server = 1; |
| kex->done = 1; |
| r = 0; |
| out: |
| if (r != 0 || kexp == NULL) { |
| if (kex != NULL) { |
| sshbuf_free(kex->my); |
| sshbuf_free(kex->peer); |
| free(kex); |
| } |
| if (kexp != NULL) |
| *kexp = NULL; |
| } else { |
| *kexp = kex; |
| } |
| return r; |
| } |
| |
| /* |
| * Restore packet state from content of blob 'm' (de-serialization). |
| * Note that 'm' will be partially consumed on parsing or any other errors. |
| */ |
| int |
| ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m) |
| { |
| struct session_state *state = ssh->state; |
| const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output; |
| size_t ssh1keylen, rlen, slen, ilen, olen; |
| int r; |
| u_int ssh1cipher = 0; |
| |
| if (!compat20) { |
| if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 || |
| (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 || |
| (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 || |
| (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 || |
| (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0) |
| return r; |
| if (ssh1cipher > INT_MAX) |
| return SSH_ERR_KEY_UNKNOWN_CIPHER; |
| ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen, |
| (int)ssh1cipher); |
| if (cipher_get_keyiv_len(state->send_context) != (int)slen || |
| cipher_get_keyiv_len(state->receive_context) != (int)rlen) |
| return SSH_ERR_INVALID_FORMAT; |
| if ((r = cipher_set_keyiv(state->send_context, ivout)) != 0 || |
| (r = cipher_set_keyiv(state->receive_context, ivin)) != 0) |
| return r; |
| } else { |
| if ((r = kex_from_blob(m, &ssh->kex)) != 0 || |
| (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 || |
| (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 || |
| (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 || |
| (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 || |
| (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 || |
| (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 || |
| (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 || |
| (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 || |
| (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 || |
| (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 || |
| (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 || |
| (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0) |
| return r; |
| /* |
| * We set the time here so that in post-auth privsep slave we |
| * count from the completion of the authentication. |
| */ |
| state->rekey_time = monotime(); |
| /* XXX ssh_set_newkeys overrides p_read.packets? XXX */ |
| if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 || |
| (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0) |
| return r; |
| } |
| if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 || |
| (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0) |
| return r; |
| if (cipher_get_keycontext(state->send_context, NULL) != (int)slen || |
| cipher_get_keycontext(state->receive_context, NULL) != (int)rlen) |
| return SSH_ERR_INVALID_FORMAT; |
| cipher_set_keycontext(state->send_context, keyout); |
| cipher_set_keycontext(state->receive_context, keyin); |
| |
| if ((r = ssh_packet_set_compress_state(ssh, m)) != 0 || |
| (r = ssh_packet_set_postauth(ssh)) != 0) |
| return r; |
| |
| sshbuf_reset(state->input); |
| sshbuf_reset(state->output); |
| if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 || |
| (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 || |
| (r = sshbuf_put(state->input, input, ilen)) != 0 || |
| (r = sshbuf_put(state->output, output, olen)) != 0) |
| return r; |
| |
| if (sshbuf_len(m)) |
| return SSH_ERR_INVALID_FORMAT; |
| debug3("%s: done", __func__); |
| return 0; |
| } |
| |
| /* NEW API */ |
| |
| /* put data to the outgoing packet */ |
| |
| int |
| sshpkt_put(struct ssh *ssh, const void *v, size_t len) |
| { |
| return sshbuf_put(ssh->state->outgoing_packet, v, len); |
| } |
| |
| int |
| sshpkt_putb(struct ssh *ssh, const struct sshbuf *b) |
| { |
| return sshbuf_putb(ssh->state->outgoing_packet, b); |
| } |
| |
| int |
| sshpkt_put_u8(struct ssh *ssh, u_char val) |
| { |
| return sshbuf_put_u8(ssh->state->outgoing_packet, val); |
| } |
| |
| int |
| sshpkt_put_u32(struct ssh *ssh, u_int32_t val) |
| { |
| return sshbuf_put_u32(ssh->state->outgoing_packet, val); |
| } |
| |
| int |
| sshpkt_put_u64(struct ssh *ssh, u_int64_t val) |
| { |
| return sshbuf_put_u64(ssh->state->outgoing_packet, val); |
| } |
| |
| int |
| sshpkt_put_string(struct ssh *ssh, const void *v, size_t len) |
| { |
| return sshbuf_put_string(ssh->state->outgoing_packet, v, len); |
| } |
| |
| int |
| sshpkt_put_cstring(struct ssh *ssh, const void *v) |
| { |
| return sshbuf_put_cstring(ssh->state->outgoing_packet, v); |
| } |
| |
| int |
| sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v) |
| { |
| return sshbuf_put_stringb(ssh->state->outgoing_packet, v); |
| } |
| |
| #ifdef WITH_OPENSSL |
| #ifdef OPENSSL_HAS_ECC |
| int |
| sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g) |
| { |
| return sshbuf_put_ec(ssh->state->outgoing_packet, v, g); |
| } |
| #endif /* OPENSSL_HAS_ECC */ |
| |
| #ifdef WITH_SSH1 |
| int |
| sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v) |
| { |
| return sshbuf_put_bignum1(ssh->state->outgoing_packet, v); |
| } |
| #endif /* WITH_SSH1 */ |
| |
| int |
| sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v) |
| { |
| return sshbuf_put_bignum2(ssh->state->outgoing_packet, v); |
| } |
| #endif /* WITH_OPENSSL */ |
| |
| /* fetch data from the incoming packet */ |
| |
| int |
| sshpkt_get(struct ssh *ssh, void *valp, size_t len) |
| { |
| return sshbuf_get(ssh->state->incoming_packet, valp, len); |
| } |
| |
| int |
| sshpkt_get_u8(struct ssh *ssh, u_char *valp) |
| { |
| return sshbuf_get_u8(ssh->state->incoming_packet, valp); |
| } |
| |
| int |
| sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp) |
| { |
| return sshbuf_get_u32(ssh->state->incoming_packet, valp); |
| } |
| |
| int |
| sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp) |
| { |
| return sshbuf_get_u64(ssh->state->incoming_packet, valp); |
| } |
| |
| int |
| sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp) |
| { |
| return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp); |
| } |
| |
| int |
| sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp) |
| { |
| return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp); |
| } |
| |
| int |
| sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp) |
| { |
| return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp); |
| } |
| |
| #ifdef WITH_OPENSSL |
| #ifdef OPENSSL_HAS_ECC |
| int |
| sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g) |
| { |
| return sshbuf_get_ec(ssh->state->incoming_packet, v, g); |
| } |
| #endif /* OPENSSL_HAS_ECC */ |
| |
| #ifdef WITH_SSH1 |
| int |
| sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v) |
| { |
| return sshbuf_get_bignum1(ssh->state->incoming_packet, v); |
| } |
| #endif /* WITH_SSH1 */ |
| |
| int |
| sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v) |
| { |
| return sshbuf_get_bignum2(ssh->state->incoming_packet, v); |
| } |
| #endif /* WITH_OPENSSL */ |
| |
| int |
| sshpkt_get_end(struct ssh *ssh) |
| { |
| if (sshbuf_len(ssh->state->incoming_packet) > 0) |
| return SSH_ERR_UNEXPECTED_TRAILING_DATA; |
| return 0; |
| } |
| |
| const u_char * |
| sshpkt_ptr(struct ssh *ssh, size_t *lenp) |
| { |
| if (lenp != NULL) |
| *lenp = sshbuf_len(ssh->state->incoming_packet); |
| return sshbuf_ptr(ssh->state->incoming_packet); |
| } |
| |
| /* start a new packet */ |
| |
| int |
| sshpkt_start(struct ssh *ssh, 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; |
| sshbuf_reset(ssh->state->outgoing_packet); |
| return sshbuf_put(ssh->state->outgoing_packet, buf, len); |
| } |
| |
| /* send it */ |
| |
| int |
| sshpkt_send(struct ssh *ssh) |
| { |
| if (compat20) |
| return ssh_packet_send2(ssh); |
| else |
| return ssh_packet_send1(ssh); |
| } |
| |
| int |
| sshpkt_disconnect(struct ssh *ssh, const char *fmt,...) |
| { |
| char buf[1024]; |
| va_list args; |
| int r; |
| |
| va_start(args, fmt); |
| vsnprintf(buf, sizeof(buf), fmt, args); |
| va_end(args); |
| |
| if (compat20) { |
| if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 || |
| (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 || |
| (r = sshpkt_put_cstring(ssh, buf)) != 0 || |
| (r = sshpkt_put_cstring(ssh, "")) != 0 || |
| (r = sshpkt_send(ssh)) != 0) |
| return r; |
| } else { |
| if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 || |
| (r = sshpkt_put_cstring(ssh, buf)) != 0 || |
| (r = sshpkt_send(ssh)) != 0) |
| return r; |
| } |
| return 0; |
| } |
| |
| /* roundup current message to pad bytes */ |
| int |
| sshpkt_add_padding(struct ssh *ssh, u_char pad) |
| { |
| ssh->state->extra_pad = pad; |
| return 0; |
| } |