diff options
Diffstat (limited to 'libssh/packet1.c')
-rw-r--r-- | libssh/packet1.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/libssh/packet1.c b/libssh/packet1.c new file mode 100644 index 00000000..156a6506 --- /dev/null +++ b/libssh/packet1.c @@ -0,0 +1,349 @@ +/* + * This file is part of the SSH Library + * + * Copyright (c) 2010 by Aris Adamantiadis + * + * The SSH Library is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation; either version 2.1 of the License, or (at your + * option) any later version. + * + * The SSH Library is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public + * License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with the SSH Library; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA. + */ + +#include "config.h" +#include "libssh/priv.h" +#include "libssh/ssh1.h" +#include "libssh/packet.h" +#include "libssh/session.h" +#include "libssh/buffer.h" +#include "libssh/socket.h" + +#ifdef WITH_SSH1 +/* a slightly modified packet_read2() for SSH-1 protocol + * TODO: should be transformed in an asynchronous socket callback + */ +int packet_read(ssh_session session) { + void *packet = NULL; + int rc = SSH_ERROR; + int to_be_read; + uint32_t padding; + uint32_t crc; + uint32_t len; + + enter_function(); + + if(!session->alive) { + goto error; + } + + switch (session->packet_state){ + case PACKET_STATE_INIT: + memset(&session->in_packet, 0, sizeof(PACKET)); + + if (session->in_buffer) { + if (buffer_reinit(session->in_buffer) < 0) { + goto error; + } + } else { + session->in_buffer = buffer_new(); + if (session->in_buffer == NULL) { + goto error; + } + } + + rc = ssh_socket_read(session->socket, &len, sizeof(uint32_t)); + if (rc != SSH_OK) { + goto error; + } + + rc = SSH_ERROR; + + /* len is not encrypted */ + len = ntohl(len); + if (len > MAX_PACKET_LEN) { + ssh_set_error(session, SSH_FATAL, + "read_packet(): Packet len too high (%u %.8x)", len, len); + goto error; + } + + ssh_log(session, SSH_LOG_PACKET, "Reading a %d bytes packet", len); + + session->in_packet.len = len; + session->packet_state = PACKET_STATE_SIZEREAD; + case PACKET_STATE_SIZEREAD: + len = session->in_packet.len; + /* SSH-1 has a fixed padding lenght */ + padding = 8 - (len % 8); + to_be_read = len + padding; + + /* it is _not_ possible that to_be_read be < 8. */ + packet = malloc(to_be_read); + if (packet == NULL) { + ssh_set_error(session, SSH_FATAL, "Not enough space"); + goto error; + } + + rc = ssh_socket_read(session->socket, packet, to_be_read); + if(rc != SSH_OK) { + SAFE_FREE(packet); + goto error; + } + rc = SSH_ERROR; + + if (buffer_add_data(session->in_buffer,packet,to_be_read) < 0) { + SAFE_FREE(packet); + goto error; + } + SAFE_FREE(packet); + +#ifdef DEBUG_CRYPTO + ssh_print_hexa("read packet:", buffer_get(session->in_buffer), + buffer_get_len(session->in_buffer)); +#endif + if (session->current_crypto) { + /* + * We decrypt everything, missing the lenght part (which was + * previously read, unencrypted, and is not part of the buffer + */ + if (packet_decrypt(session, + buffer_get(session->in_buffer), + buffer_get_len(session->in_buffer)) < 0) { + ssh_set_error(session, SSH_FATAL, "Packet decrypt error"); + goto error; + } + } +#ifdef DEBUG_CRYPTO + ssh_print_hexa("read packet decrypted:", buffer_get(session->in_buffer), + buffer_get_len(session->in_buffer)); +#endif + ssh_log(session, SSH_LOG_PACKET, "%d bytes padding", padding); + if(((len + padding) != buffer_get_rest_len(session->in_buffer)) || + ((len + padding) < sizeof(uint32_t))) { + ssh_log(session, SSH_LOG_RARE, "no crc32 in packet"); + ssh_set_error(session, SSH_FATAL, "no crc32 in packet"); + goto error; + } + + memcpy(&crc, + (unsigned char *)buffer_get_rest(session->in_buffer) + (len+padding) - sizeof(uint32_t), + sizeof(uint32_t)); + buffer_pass_bytes_end(session->in_buffer, sizeof(uint32_t)); + crc = ntohl(crc); + if (ssh_crc32(buffer_get_rest(session->in_buffer), + (len + padding) - sizeof(uint32_t)) != crc) { +#ifdef DEBUG_CRYPTO + ssh_print_hexa("crc32 on",buffer_get_rest(session->in_buffer), + len + padding - sizeof(uint32_t)); +#endif + ssh_log(session, SSH_LOG_RARE, "Invalid crc32"); + ssh_set_error(session, SSH_FATAL, + "Invalid crc32: expected %.8x, got %.8x", + crc, + ssh_crc32(buffer_get_rest(session->in_buffer), + len + padding - sizeof(uint32_t))); + goto error; + } + /* pass the padding */ + buffer_pass_bytes(session->in_buffer, padding); + ssh_log(session, SSH_LOG_PACKET, "The packet is valid"); + +/* TODO FIXME +#if defined(HAVE_LIBZ) && defined(WITH_LIBZ) + if(session->current_crypto && session->current_crypto->do_compress_in){ + decompress_buffer(session,session->in_buffer); + } +#endif +*/ + session->recv_seq++; + session->packet_state=PACKET_STATE_INIT; + + leave_function(); + return SSH_OK; + } /* switch */ + + ssh_set_error(session, SSH_FATAL, + "Invalid state into packet_read1(): %d", + session->packet_state); +error: + leave_function(); + return rc; +} + +#endif /* WITH_SSH1 */ +#ifdef WITH_SSH1 +int packet_send1(ssh_session session) { + unsigned int blocksize = (session->current_crypto ? + session->current_crypto->out_cipher->blocksize : 8); + uint32_t currentlen = buffer_get_len(session->out_buffer) + sizeof(uint32_t); + char padstring[32] = {0}; + int rc = SSH_ERROR; + uint32_t finallen; + uint32_t crc; + uint8_t padding; + + enter_function(); + ssh_log(session,SSH_LOG_PACKET,"Sending a %d bytes long packet",currentlen); + +/* TODO FIXME +#if defined(HAVE_LIBZ) && defined(WITH_LIBZ) + if (session->current_crypto && session->current_crypto->do_compress_out) { + if (compress_buffer(session, session->out_buffer) < 0) { + goto error; + } + currentlen = buffer_get_len(session->out_buffer); + } +#endif +*/ + padding = blocksize - (currentlen % blocksize); + if (session->current_crypto) { + ssh_get_random(padstring, padding, 0); + } else { + memset(padstring, 0, padding); + } + + finallen = htonl(currentlen); + ssh_log(session, SSH_LOG_PACKET, + "%d bytes after comp + %d padding bytes = %d bytes packet", + currentlen, padding, ntohl(finallen)); + + if (buffer_prepend_data(session->out_buffer, &padstring, padding) < 0) { + goto error; + } + if (buffer_prepend_data(session->out_buffer, &finallen, sizeof(uint32_t)) < 0) { + goto error; + } + + crc = ssh_crc32((char *)buffer_get(session->out_buffer) + sizeof(uint32_t), + buffer_get_len(session->out_buffer) - sizeof(uint32_t)); + + if (buffer_add_u32(session->out_buffer, ntohl(crc)) < 0) { + goto error; + } + +#ifdef DEBUG_CRYPTO + ssh_print_hexa("Clear packet", buffer_get(session->out_buffer), + buffer_get_len(session->out_buffer)); +#endif + + packet_encrypt(session, (unsigned char *)buffer_get(session->out_buffer) + sizeof(uint32_t), + buffer_get_len(session->out_buffer) - sizeof(uint32_t)); + +#ifdef DEBUG_CRYPTO + ssh_print_hexa("encrypted packet",buffer_get(session->out_buffer), + buffer_get_len(session->out_buffer)); +#endif + if (ssh_socket_write(session->socket, buffer_get(session->out_buffer), + buffer_get_len(session->out_buffer)) == SSH_ERROR) { + goto error; + } + + rc = packet_flush(session, 0); + session->send_seq++; + + if (buffer_reinit(session->out_buffer) < 0) { + rc = SSH_ERROR; + } +error: + leave_function(); + return rc; /* SSH_OK, AGAIN or ERROR */ +} + +#endif /* WITH_SSH1 */ +#ifdef WITH_SSH1 +static void packet_parse(ssh_session session) { + uint8_t type = session->in_packet.type; + + if (session->version == 1) { + /* SSH-1 */ + switch(type) { + case SSH_MSG_DISCONNECT: + ssh_log(session, SSH_LOG_PACKET, "Received SSH_MSG_DISCONNECT"); + ssh_set_error(session, SSH_FATAL, "Received SSH_MSG_DISCONNECT"); + + ssh_socket_close(session->socket); + session->alive = 0; + return; + case SSH_SMSG_STDOUT_DATA: + case SSH_SMSG_STDERR_DATA: + case SSH_SMSG_EXITSTATUS: + channel_handle1(session,type); + return; + case SSH_MSG_DEBUG: + case SSH_MSG_IGNORE: + break; + default: + ssh_log(session, SSH_LOG_PACKET, + "Unexpected message code %d", type); + } + return; + } else { + } +} + +int packet_wait(ssh_session session, int type, int blocking) { + + enter_function(); + + ssh_log(session, SSH_LOG_PROTOCOL, "packet_wait1 waiting for %d", type); + + do { + if ((packet_read(session) != SSH_OK) || + (packet_translate(session) != SSH_OK)) { + leave_function(); + return SSH_ERROR; + } + ssh_log(session, SSH_LOG_PACKET, "packet_wait1() received a type %d packet", + session->in_packet.type); + switch (session->in_packet.type) { + case SSH_MSG_DISCONNECT: + packet_parse(session); + leave_function(); + return SSH_ERROR; + case SSH_SMSG_STDOUT_DATA: + case SSH_SMSG_STDERR_DATA: + case SSH_SMSG_EXITSTATUS: + if (channel_handle1(session,type) < 0) { + leave_function(); + return SSH_ERROR; + } + break; + case SSH_MSG_DEBUG: + case SSH_MSG_IGNORE: + break; + /* case SSH2_MSG_CHANNEL_CLOSE: + packet_parse(session); + break;; + */ + default: + if (type && (type != session->in_packet.type)) { + ssh_set_error(session, SSH_FATAL, + "packet_wait1(): Received a %d type packet, but expected %d\n", + session->in_packet.type, type); + leave_function(); + return SSH_ERROR; + } + leave_function(); + return SSH_OK; + } + + if (blocking == 0) { + leave_function(); + return SSH_OK; + } + } while(1); + + leave_function(); + return SSH_OK; +} +#endif /* WITH_SSH1 */ + +/* vim: set ts=2 sw=2 et cindent: */ |