X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/0b582e461dc11f0887b249b6b60bbbf52687850d..b5afdff53b51d529e596da3b4c2aa5ee14cc8b08:/openssh/packet.c diff --git a/openssh/packet.c b/openssh/packet.c index 49c6e7a..06c19f5 100644 --- a/openssh/packet.c +++ b/openssh/packet.c @@ -1,3 +1,4 @@ +/* $OpenBSD: packet.c,v 1.166 2009/06/27 09:29:06 andreas Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -37,28 +38,46 @@ */ #include "includes.h" -RCSID("$OpenBSD: packet.c,v 1.72 2001/11/10 13:37:20 markus Exp $"); + +#include +#include "openbsd-compat/sys-queue.h" +#include +#include +#ifdef HAVE_SYS_TIME_H +# include +#endif + +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include #include "xmalloc.h" #include "buffer.h" #include "packet.h" -#include "bufaux.h" #include "crc32.h" -#include "getput.h" - #include "compress.h" #include "deattack.h" #include "channels.h" - #include "compat.h" #include "ssh1.h" #include "ssh2.h" - #include "cipher.h" +#include "key.h" #include "kex.h" #include "mac.h" #include "log.h" #include "canohost.h" +#include "misc.h" +#include "ssh.h" +#include "roaming.h" #ifdef PACKET_DEBUG #define DBG(x) x @@ -66,57 +85,128 @@ RCSID("$OpenBSD: packet.c,v 1.72 2001/11/10 13:37:20 markus Exp $"); #define DBG(x) #endif -/* - * 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. - */ -static int connection_in = -1; -static int connection_out = -1; +#define PACKET_MAX_SIZE (256 * 1024) + +struct packet_state { + u_int32_t seqnr; + u_int32_t packets; + u_int64_t blocks; + u_int64_t bytes; +}; + +struct packet { + TAILQ_ENTRY(packet) next; + u_char type; + Buffer payload; +}; + +struct session_state { + /* + * This variable contains the file descriptors used for + * communicating with the other side. connection_in is used for + * reading; connection_out for writing. These can be the same + * descriptor, in which case it is assumed to be a socket. + */ + int connection_in; + int connection_out; + + /* Protocol flags for the remote side. */ + u_int remote_protocol_flags; + + /* Encryption context for receiving data. Only used for decryption. */ + CipherContext receive_context; + + /* Encryption context for sending data. Only used for encryption. */ + CipherContext send_context; + + /* Buffer for raw input data from the socket. */ + Buffer input; + + /* Buffer for raw output data going to the socket. */ + Buffer output; + + /* Buffer for the partial outgoing packet being constructed. */ + Buffer outgoing_packet; -/* Protocol flags for the remote side. */ -static u_int remote_protocol_flags = 0; + /* Buffer for the incoming packet currently being processed. */ + Buffer incoming_packet; -/* Encryption context for receiving data. This is only used for decryption. */ -static CipherContext receive_context; + /* Scratch buffer for packet compression/decompression. */ + Buffer compression_buffer; + int compression_buffer_ready; -/* Encryption context for sending data. This is only used for encryption. */ -static CipherContext send_context; + /* + * Flag indicating whether packet compression/decompression is + * enabled. + */ + int packet_compression; + + /* default maximum packet size */ + u_int max_packet_size; + + /* Flag indicating whether this module has been initialized. */ + int initialized; + + /* Set to true if the connection is interactive. */ + int interactive_mode; + + /* Set to true if we are the server side. */ + int server_side; + + /* Set to true if we are authenticated. */ + int after_authentication; + + int keep_alive_timeouts; + + /* The maximum time that we will wait to send or receive a packet */ + int packet_timeout_ms; + + /* Session key information for Encryption and MAC */ + Newkeys *newkeys[MODE_MAX]; + struct packet_state p_read, p_send; -/* Buffer for raw input data from the socket. */ -static Buffer input; + u_int64_t max_blocks_in, max_blocks_out; + u_int32_t rekey_limit; -/* Buffer for raw output data going to the socket. */ -static Buffer output; + /* Session key for protocol v1 */ + u_char ssh1_key[SSH_SESSION_KEY_LENGTH]; + u_int ssh1_keylen; -/* Buffer for the partial outgoing packet being constructed. */ -static Buffer outgoing_packet; + /* roundup current message to extra_pad bytes */ + u_char extra_pad; -/* Buffer for the incoming packet currently being processed. */ -static Buffer incoming_packet; + /* XXX discard incoming data after MAC error */ + u_int packet_discard; + Mac *packet_discard_mac; -/* Scratch buffer for packet compression/decompression. */ -static Buffer compression_buffer; -static int compression_buffer_ready = 0; + /* Used in packet_read_poll2() */ + u_int packlen; -/* Flag indicating whether packet compression/decompression is enabled. */ -static int packet_compression = 0; + /* Used in packet_send2 */ + int rekeying; -/* default maximum packet size */ -int max_packet_size = 32768; + /* Used in packet_set_interactive */ + int set_interactive_called; -/* Flag indicating whether this module has been initialized. */ -static int initialized = 0; + /* Used in packet_set_maxsize */ + int set_maxsize_called; -/* Set to true if the connection is interactive. */ -static int interactive_mode = 0; + TAILQ_HEAD(, packet) outgoing; +}; -/* Session key information for Encryption and MAC */ -Newkeys *newkeys[MODE_MAX]; +static struct session_state *active_state, *backup_state; -/* roundup current message to extra_pad bytes */ -static u_char extra_pad = 0; +static struct session_state * +alloc_session_state(void) +{ + struct session_state *s = xcalloc(1, sizeof(*s)); + + s->connection_in = -1; + s->connection_out = -1; + s->max_packet_size = 32768; + s->packet_timeout_ms = -1; + return s; +} /* * Sets the descriptors used for communication. Disables encryption until @@ -126,42 +216,95 @@ void packet_set_connection(int fd_in, int fd_out) { Cipher *none = cipher_by_name("none"); + if (none == NULL) fatal("packet_set_connection: cannot load cipher 'none'"); - connection_in = fd_in; - connection_out = fd_out; - cipher_init(&send_context, none, (u_char *) "", 0, NULL, 0); - cipher_init(&receive_context, none, (u_char *) "", 0, NULL, 0); - newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL; - if (!initialized) { - initialized = 1; - buffer_init(&input); - buffer_init(&output); - buffer_init(&outgoing_packet); - buffer_init(&incoming_packet); + if (active_state == NULL) + active_state = alloc_session_state(); + active_state->connection_in = fd_in; + active_state->connection_out = fd_out; + cipher_init(&active_state->send_context, none, (const u_char *)"", + 0, NULL, 0, CIPHER_ENCRYPT); + cipher_init(&active_state->receive_context, none, (const u_char *)"", + 0, NULL, 0, CIPHER_DECRYPT); + active_state->newkeys[MODE_IN] = active_state->newkeys[MODE_OUT] = NULL; + if (!active_state->initialized) { + active_state->initialized = 1; + buffer_init(&active_state->input); + buffer_init(&active_state->output); + buffer_init(&active_state->outgoing_packet); + buffer_init(&active_state->incoming_packet); + TAILQ_INIT(&active_state->outgoing); + active_state->p_send.packets = active_state->p_read.packets = 0; } - /* Kludge: arrange the close function to be called from fatal(). */ - fatal_add_cleanup((void (*) (void *)) packet_close, NULL); +} + +void +packet_set_timeout(int timeout, int count) +{ + if (timeout == 0 || count == 0) { + active_state->packet_timeout_ms = -1; + return; + } + if ((INT_MAX / 1000) / count < timeout) + active_state->packet_timeout_ms = INT_MAX; + else + active_state->packet_timeout_ms = timeout * count * 1000; +} + +static void +packet_stop_discard(void) +{ + if (active_state->packet_discard_mac) { + char buf[1024]; + + memset(buf, 'a', sizeof(buf)); + while (buffer_len(&active_state->incoming_packet) < + PACKET_MAX_SIZE) + buffer_append(&active_state->incoming_packet, buf, + sizeof(buf)); + (void) mac_compute(active_state->packet_discard_mac, + active_state->p_read.seqnr, + buffer_ptr(&active_state->incoming_packet), + PACKET_MAX_SIZE); + } + logit("Finished discarding for %.200s", get_remote_ipaddr()); + cleanup_exit(255); +} + +static void +packet_start_discard(Enc *enc, Mac *mac, u_int packet_length, u_int discard) +{ + if (enc == NULL || !cipher_is_cbc(enc->cipher)) + packet_disconnect("Packet corrupt"); + if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled) + active_state->packet_discard_mac = mac; + if (buffer_len(&active_state->input) >= discard) + packet_stop_discard(); + active_state->packet_discard = discard - + buffer_len(&active_state->input); } /* Returns 1 if remote host is connected via socket, 0 if not. */ int -packet_connection_is_on_socket() +packet_connection_is_on_socket(void) { struct sockaddr_storage from, to; socklen_t fromlen, tolen; /* filedescriptors in and out are the same, so it's a socket */ - if (connection_in == connection_out) + if (active_state->connection_in == active_state->connection_out) return 1; fromlen = sizeof(from); memset(&from, 0, sizeof(from)); - if (getpeername(connection_in, (struct sockaddr *)&from, &fromlen) < 0) + if (getpeername(active_state->connection_in, (struct sockaddr *)&from, + &fromlen) < 0) return 0; tolen = sizeof(to); memset(&to, 0, sizeof(to)); - if (getpeername(connection_out, (struct sockaddr *)&to, &tolen) < 0) + if (getpeername(active_state->connection_out, (struct sockaddr *)&to, + &tolen) < 0) return 0; if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0) return 0; @@ -170,76 +313,190 @@ packet_connection_is_on_socket() return 1; } +/* + * Exports an IV from the CipherContext required to export the key + * state back from the unprivileged child to the privileged parent + * process. + */ + +void +packet_get_keyiv(int mode, u_char *iv, u_int len) +{ + CipherContext *cc; + + if (mode == MODE_OUT) + cc = &active_state->send_context; + else + cc = &active_state->receive_context; + + cipher_get_keyiv(cc, iv, len); +} + +int +packet_get_keycontext(int mode, u_char *dat) +{ + CipherContext *cc; + + if (mode == MODE_OUT) + cc = &active_state->send_context; + else + cc = &active_state->receive_context; + + return (cipher_get_keycontext(cc, dat)); +} + +void +packet_set_keycontext(int mode, u_char *dat) +{ + CipherContext *cc; + + if (mode == MODE_OUT) + cc = &active_state->send_context; + else + cc = &active_state->receive_context; + + cipher_set_keycontext(cc, dat); +} + +int +packet_get_keyiv_len(int mode) +{ + CipherContext *cc; + + if (mode == MODE_OUT) + cc = &active_state->send_context; + else + cc = &active_state->receive_context; + + return (cipher_get_keyiv_len(cc)); +} + +void +packet_set_iv(int mode, u_char *dat) +{ + CipherContext *cc; + + if (mode == MODE_OUT) + cc = &active_state->send_context; + else + cc = &active_state->receive_context; + + cipher_set_keyiv(cc, dat); +} + +int +packet_get_ssh1_cipher(void) +{ + return (cipher_get_number(active_state->receive_context.cipher)); +} + +void +packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks, u_int32_t *packets, + u_int64_t *bytes) +{ + struct packet_state *state; + + state = (mode == MODE_IN) ? + &active_state->p_read : &active_state->p_send; + if (seqnr) + *seqnr = state->seqnr; + if (blocks) + *blocks = state->blocks; + if (packets) + *packets = state->packets; + if (bytes) + *bytes = state->bytes; +} + +void +packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets, + u_int64_t bytes) +{ + struct packet_state *state; + + state = (mode == MODE_IN) ? + &active_state->p_read : &active_state->p_send; + state->seqnr = seqnr; + state->blocks = blocks; + state->packets = packets; + state->bytes = bytes; +} + /* returns 1 if connection is via ipv4 */ int -packet_connection_is_ipv4() +packet_connection_is_ipv4(void) { struct sockaddr_storage to; socklen_t tolen = sizeof(to); memset(&to, 0, sizeof(to)); - if (getsockname(connection_out, (struct sockaddr *)&to, &tolen) < 0) - return 0; - if (to.ss_family != AF_INET) + if (getsockname(active_state->connection_out, (struct sockaddr *)&to, + &tolen) < 0) return 0; - return 1; + if (to.ss_family == AF_INET) + return 1; +#ifdef IPV4_IN_IPV6 + if (to.ss_family == AF_INET6 && + IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr)) + return 1; +#endif + return 0; } /* Sets the connection into non-blocking mode. */ void -packet_set_nonblocking() +packet_set_nonblocking(void) { /* Set the socket into non-blocking mode. */ - if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0) - error("fcntl O_NONBLOCK: %.100s", strerror(errno)); + set_nonblock(active_state->connection_in); - if (connection_out != connection_in) { - if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0) - error("fcntl O_NONBLOCK: %.100s", strerror(errno)); - } + if (active_state->connection_out != active_state->connection_in) + set_nonblock(active_state->connection_out); } /* Returns the socket used for reading. */ int -packet_get_connection_in() +packet_get_connection_in(void) { - return connection_in; + return active_state->connection_in; } /* Returns the descriptor used for writing. */ int -packet_get_connection_out() +packet_get_connection_out(void) { - return connection_out; + return active_state->connection_out; } /* Closes the connection and clears and frees internal data structures. */ void -packet_close() +packet_close(void) { - if (!initialized) + if (!active_state->initialized) return; - initialized = 0; - if (connection_in == connection_out) { - shutdown(connection_out, SHUT_RDWR); - close(connection_out); + active_state->initialized = 0; + if (active_state->connection_in == active_state->connection_out) { + shutdown(active_state->connection_out, SHUT_RDWR); + close(active_state->connection_out); } else { - close(connection_in); - close(connection_out); + close(active_state->connection_in); + close(active_state->connection_out); } - buffer_free(&input); - buffer_free(&output); - buffer_free(&outgoing_packet); - buffer_free(&incoming_packet); - if (compression_buffer_ready) { - buffer_free(&compression_buffer); + buffer_free(&active_state->input); + buffer_free(&active_state->output); + buffer_free(&active_state->outgoing_packet); + buffer_free(&active_state->incoming_packet); + if (active_state->compression_buffer_ready) { + buffer_free(&active_state->compression_buffer); buffer_compress_uninit(); } + cipher_cleanup(&active_state->send_context); + cipher_cleanup(&active_state->receive_context); } /* Sets remote side protocol flags. */ @@ -247,15 +504,15 @@ packet_close() void packet_set_protocol_flags(u_int protocol_flags) { - remote_protocol_flags = protocol_flags; + active_state->remote_protocol_flags = protocol_flags; } /* Returns the remote protocol flags set earlier by the above function. */ u_int -packet_get_protocol_flags() +packet_get_protocol_flags(void) { - return remote_protocol_flags; + return active_state->remote_protocol_flags; } /* @@ -266,18 +523,18 @@ packet_get_protocol_flags() static void packet_init_compression(void) { - if (compression_buffer_ready == 1) + if (active_state->compression_buffer_ready == 1) return; - compression_buffer_ready = 1; - buffer_init(&compression_buffer); + active_state->compression_buffer_ready = 1; + buffer_init(&active_state->compression_buffer); } void packet_start_compression(int level) { - if (packet_compression && !compat20) + if (active_state->packet_compression && !compat20) fatal("Compression already enabled."); - packet_compression = 1; + active_state->packet_compression = 1; packet_init_compression(); buffer_compress_init_send(level); buffer_compress_init_recv(); @@ -288,17 +545,34 @@ packet_start_compression(int level) * key is used for both sending and reception. However, both directions are * encrypted independently of each other. */ + void packet_set_encryption_key(const u_char *key, u_int keylen, int number) { Cipher *cipher = cipher_by_number(number); + if (cipher == NULL) fatal("packet_set_encryption_key: unknown cipher number %d", number); if (keylen < 20) fatal("packet_set_encryption_key: keylen too small: %d", keylen); - cipher_init(&receive_context, cipher, key, keylen, NULL, 0); - cipher_init(&send_context, cipher, key, keylen, NULL, 0); + if (keylen > SSH_SESSION_KEY_LENGTH) + fatal("packet_set_encryption_key: keylen too big: %d", keylen); + memcpy(active_state->ssh1_key, key, keylen); + active_state->ssh1_keylen = keylen; + cipher_init(&active_state->send_context, cipher, key, keylen, NULL, + 0, CIPHER_ENCRYPT); + cipher_init(&active_state->receive_context, cipher, key, keylen, NULL, + 0, CIPHER_DECRYPT); +} + +u_int +packet_get_encryption_key(u_char *key) +{ + if (key == NULL) + return (active_state->ssh1_keylen); + memcpy(key, active_state->ssh1_key, active_state->ssh1_keylen); + return (active_state->ssh1_keylen); } /* Start constructing a packet to send. */ @@ -312,8 +586,8 @@ packet_start(u_char type) len = compat20 ? 6 : 9; memset(buf, 0, len - 1); buf[len - 1] = type; - buffer_clear(&outgoing_packet); - buffer_append(&outgoing_packet, buf, len); + buffer_clear(&active_state->outgoing_packet); + buffer_append(&active_state->outgoing_packet, buf, len); } /* Append payload. */ @@ -321,37 +595,50 @@ void packet_put_char(int value) { char ch = value; - buffer_append(&outgoing_packet, &ch, 1); + + buffer_append(&active_state->outgoing_packet, &ch, 1); } + void packet_put_int(u_int value) { - buffer_put_int(&outgoing_packet, value); + buffer_put_int(&active_state->outgoing_packet, value); +} + +void +packet_put_int64(u_int64_t value) +{ + buffer_put_int64(&active_state->outgoing_packet, value); } + void -packet_put_string(const char *buf, u_int len) +packet_put_string(const void *buf, u_int len) { - buffer_put_string(&outgoing_packet, buf, len); + buffer_put_string(&active_state->outgoing_packet, buf, len); } + void packet_put_cstring(const char *str) { - buffer_put_cstring(&outgoing_packet, str); + buffer_put_cstring(&active_state->outgoing_packet, str); } + void -packet_put_raw(const char *buf, u_int len) +packet_put_raw(const void *buf, u_int len) { - buffer_append(&outgoing_packet, buf, len); + buffer_append(&active_state->outgoing_packet, buf, len); } + void packet_put_bignum(BIGNUM * value) { - buffer_put_bignum(&outgoing_packet, value); + buffer_put_bignum(&active_state->outgoing_packet, value); } + void packet_put_bignum2(BIGNUM * value) { - buffer_put_bignum2(&outgoing_packet, value); + buffer_put_bignum2(&active_state->outgoing_packet, value); } /* @@ -362,115 +649,137 @@ packet_put_bignum2(BIGNUM * value) static void packet_send1(void) { - char buf[8], *cp; + u_char buf[8], *cp; int i, padding, len; u_int checksum; - u_int32_t rand = 0; + u_int32_t rnd = 0; /* * If using packet compression, compress the payload of the outgoing * packet. */ - if (packet_compression) { - buffer_clear(&compression_buffer); + if (active_state->packet_compression) { + buffer_clear(&active_state->compression_buffer); /* Skip padding. */ - buffer_consume(&outgoing_packet, 8); + buffer_consume(&active_state->outgoing_packet, 8); /* padding */ - buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8); - buffer_compress(&outgoing_packet, &compression_buffer); - buffer_clear(&outgoing_packet); - buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), - buffer_len(&compression_buffer)); + buffer_append(&active_state->compression_buffer, + "\0\0\0\0\0\0\0\0", 8); + buffer_compress(&active_state->outgoing_packet, + &active_state->compression_buffer); + buffer_clear(&active_state->outgoing_packet); + buffer_append(&active_state->outgoing_packet, + buffer_ptr(&active_state->compression_buffer), + buffer_len(&active_state->compression_buffer)); } /* Compute packet length without padding (add checksum, remove padding). */ - len = buffer_len(&outgoing_packet) + 4 - 8; + len = buffer_len(&active_state->outgoing_packet) + 4 - 8; /* Insert padding. Initialized to zero in packet_start1() */ padding = 8 - len % 8; - if (send_context.cipher->number != SSH_CIPHER_NONE) { - cp = buffer_ptr(&outgoing_packet); + if (!active_state->send_context.plaintext) { + cp = buffer_ptr(&active_state->outgoing_packet); for (i = 0; i < padding; i++) { if (i % 4 == 0) - rand = arc4random(); - cp[7 - i] = rand & 0xff; - rand >>= 8; + rnd = arc4random(); + cp[7 - i] = rnd & 0xff; + rnd >>= 8; } } - buffer_consume(&outgoing_packet, 8 - padding); + buffer_consume(&active_state->outgoing_packet, 8 - padding); /* Add check bytes. */ - checksum = ssh_crc32((u_char *) buffer_ptr(&outgoing_packet), - buffer_len(&outgoing_packet)); - PUT_32BIT(buf, checksum); - buffer_append(&outgoing_packet, buf, 4); + checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet), + buffer_len(&active_state->outgoing_packet)); + put_u32(buf, checksum); + buffer_append(&active_state->outgoing_packet, buf, 4); #ifdef PACKET_DEBUG fprintf(stderr, "packet_send plain: "); - buffer_dump(&outgoing_packet); + buffer_dump(&active_state->outgoing_packet); #endif /* Append to output. */ - PUT_32BIT(buf, len); - buffer_append(&output, buf, 4); - buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); - cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), - buffer_len(&outgoing_packet)); + put_u32(buf, len); + buffer_append(&active_state->output, buf, 4); + cp = buffer_append_space(&active_state->output, + buffer_len(&active_state->outgoing_packet)); + cipher_crypt(&active_state->send_context, cp, + buffer_ptr(&active_state->outgoing_packet), + buffer_len(&active_state->outgoing_packet)); #ifdef PACKET_DEBUG fprintf(stderr, "encrypted: "); - buffer_dump(&output); + buffer_dump(&active_state->output); #endif - - buffer_clear(&outgoing_packet); + active_state->p_send.packets++; + active_state->p_send.bytes += len + + buffer_len(&active_state->outgoing_packet); + buffer_clear(&active_state->outgoing_packet); /* - * Note that the packet is now only buffered in output. It won\'t be + * Note that the packet is now only buffered in output. It won't be * actually sent until packet_write_wait or packet_write_poll is * called. */ } -static void +void set_newkeys(int mode) { Enc *enc; Mac *mac; Comp *comp; CipherContext *cc; + u_int64_t *max_blocks; + int crypt_type; - debug("newkeys: mode %d", mode); - - cc = (mode == MODE_OUT) ? &send_context : &receive_context; - if (newkeys[mode] != NULL) { - debug("newkeys: rekeying"); - /* todo: free old keys, reset compression/cipher-ctxt; */ - memset(cc, 0, sizeof(*cc)); - enc = &newkeys[mode]->enc; - mac = &newkeys[mode]->mac; - comp = &newkeys[mode]->comp; - memset(mac->key, 0, mac->key_len); + debug2("set_newkeys: mode %d", mode); + + if (mode == MODE_OUT) { + cc = &active_state->send_context; + crypt_type = CIPHER_ENCRYPT; + active_state->p_send.packets = active_state->p_send.blocks = 0; + max_blocks = &active_state->max_blocks_out; + } else { + cc = &active_state->receive_context; + crypt_type = CIPHER_DECRYPT; + active_state->p_read.packets = active_state->p_read.blocks = 0; + max_blocks = &active_state->max_blocks_in; + } + if (active_state->newkeys[mode] != NULL) { + debug("set_newkeys: rekeying"); + cipher_cleanup(cc); + enc = &active_state->newkeys[mode]->enc; + mac = &active_state->newkeys[mode]->mac; + comp = &active_state->newkeys[mode]->comp; + mac_clear(mac); xfree(enc->name); xfree(enc->iv); xfree(enc->key); xfree(mac->name); xfree(mac->key); xfree(comp->name); - xfree(newkeys[mode]); + xfree(active_state->newkeys[mode]); } - newkeys[mode] = kex_get_newkeys(mode); - if (newkeys[mode] == NULL) + active_state->newkeys[mode] = kex_get_newkeys(mode); + if (active_state->newkeys[mode] == NULL) fatal("newkeys: no keys for mode %d", mode); - enc = &newkeys[mode]->enc; - mac = &newkeys[mode]->mac; - comp = &newkeys[mode]->comp; - if (mac->md != NULL) + enc = &active_state->newkeys[mode]->enc; + mac = &active_state->newkeys[mode]->mac; + comp = &active_state->newkeys[mode]->comp; + if (mac_init(mac) == 0) mac->enabled = 1; DBG(debug("cipher_init_context: %d", mode)); - cipher_init(cc, enc->cipher, enc->key, enc->cipher->key_len, - enc->iv, enc->cipher->block_size); - memset(enc->iv, 0, enc->cipher->block_size); - memset(enc->key, 0, enc->cipher->key_len); - if (comp->type != 0 && comp->enabled == 0) { + cipher_init(cc, enc->cipher, enc->key, enc->key_len, + enc->iv, enc->block_size, crypt_type); + /* Deleting the keys does not gain extra security */ + /* memset(enc->iv, 0, enc->block_size); + memset(enc->key, 0, enc->key_len); + memset(mac->key, 0, mac->key_len); */ + if ((comp->type == COMP_ZLIB || + (comp->type == COMP_DELAYED && + active_state->after_authentication)) && comp->enabled == 0) { packet_init_compression(); if (mode == MODE_OUT) buffer_compress_init_send(6); @@ -478,57 +787,100 @@ set_newkeys(int mode) buffer_compress_init_recv(); comp->enabled = 1; } + /* + * The 2^(blocksize*2) limit is too expensive for 3DES, + * blowfish, etc, so enforce a 1GB limit for small blocksizes. + */ + if (enc->block_size >= 16) + *max_blocks = (u_int64_t)1 << (enc->block_size*2); + else + *max_blocks = ((u_int64_t)1 << 30) / enc->block_size; + if (active_state->rekey_limit) + *max_blocks = MIN(*max_blocks, + active_state->rekey_limit / enc->block_size); } /* - * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) + * Delayed compression for SSH2 is enabled after authentication: + * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent, + * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received. */ static void -packet_send2(void) +packet_enable_delayed_compress(void) { - static u_int32_t seqnr = 0; - u_char type, *ucp, *macbuf = NULL; + Comp *comp = NULL; + int mode; + + /* + * Remember that we are past the authentication step, so rekeying + * with COMP_DELAYED will turn on compression immediately. + */ + active_state->after_authentication = 1; + for (mode = 0; mode < MODE_MAX; mode++) { + /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */ + if (active_state->newkeys[mode] == NULL) + continue; + comp = &active_state->newkeys[mode]->comp; + if (comp && !comp->enabled && comp->type == COMP_DELAYED) { + packet_init_compression(); + if (mode == MODE_OUT) + buffer_compress_init_send(6); + else + buffer_compress_init_recv(); + comp->enabled = 1; + } + } +} + +/* + * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) + */ +static int +packet_send2_wrapped(void) +{ + u_char type, *cp, *macbuf = NULL; u_char padlen, pad; - char *cp; u_int packet_length = 0; u_int i, len; - u_int32_t rand = 0; + u_int32_t rnd = 0; Enc *enc = NULL; Mac *mac = NULL; Comp *comp = NULL; int block_size; - if (newkeys[MODE_OUT] != NULL) { - enc = &newkeys[MODE_OUT]->enc; - mac = &newkeys[MODE_OUT]->mac; - comp = &newkeys[MODE_OUT]->comp; + if (active_state->newkeys[MODE_OUT] != NULL) { + enc = &active_state->newkeys[MODE_OUT]->enc; + mac = &active_state->newkeys[MODE_OUT]->mac; + comp = &active_state->newkeys[MODE_OUT]->comp; } - block_size = enc ? enc->cipher->block_size : 8; + block_size = enc ? enc->block_size : 8; - ucp = (u_char *) buffer_ptr(&outgoing_packet); - type = ucp[5]; + cp = buffer_ptr(&active_state->outgoing_packet); + type = cp[5]; #ifdef PACKET_DEBUG fprintf(stderr, "plain: "); - buffer_dump(&outgoing_packet); + buffer_dump(&active_state->outgoing_packet); #endif if (comp && comp->enabled) { - len = buffer_len(&outgoing_packet); + len = buffer_len(&active_state->outgoing_packet); /* skip header, compress only payload */ - buffer_consume(&outgoing_packet, 5); - buffer_clear(&compression_buffer); - buffer_compress(&outgoing_packet, &compression_buffer); - buffer_clear(&outgoing_packet); - buffer_append(&outgoing_packet, "\0\0\0\0\0", 5); - buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), - buffer_len(&compression_buffer)); + buffer_consume(&active_state->outgoing_packet, 5); + buffer_clear(&active_state->compression_buffer); + buffer_compress(&active_state->outgoing_packet, + &active_state->compression_buffer); + buffer_clear(&active_state->outgoing_packet); + buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5); + buffer_append(&active_state->outgoing_packet, + buffer_ptr(&active_state->compression_buffer), + buffer_len(&active_state->compression_buffer)); DBG(debug("compression: raw %d compressed %d", len, - buffer_len(&outgoing_packet))); + buffer_len(&active_state->outgoing_packet))); } /* sizeof (packet_len + pad_len + payload) */ - len = buffer_len(&outgoing_packet); + len = buffer_len(&active_state->outgoing_packet); /* * calc size of padding, alloc space, get random data, @@ -537,70 +889,132 @@ packet_send2(void) padlen = block_size - (len % block_size); if (padlen < 4) padlen += block_size; - if (extra_pad) { + if (active_state->extra_pad) { /* will wrap if extra_pad+padlen > 255 */ - extra_pad = roundup(extra_pad, block_size); - pad = extra_pad - ((len + padlen) % extra_pad); - debug("packet_send2: adding %d (len %d padlen %d extra_pad %d)", - pad, len, padlen, extra_pad); + active_state->extra_pad = + roundup(active_state->extra_pad, block_size); + pad = active_state->extra_pad - + ((len + padlen) % active_state->extra_pad); + debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)", + pad, len, padlen, active_state->extra_pad); padlen += pad; - extra_pad = 0; + active_state->extra_pad = 0; } - buffer_append_space(&outgoing_packet, &cp, padlen); - if (enc && enc->cipher->number != SSH_CIPHER_NONE) { + cp = buffer_append_space(&active_state->outgoing_packet, padlen); + if (enc && !active_state->send_context.plaintext) { /* random padding */ for (i = 0; i < padlen; i++) { if (i % 4 == 0) - rand = arc4random(); - cp[i] = rand & 0xff; - rand >>= 8; + rnd = arc4random(); + cp[i] = rnd & 0xff; + rnd >>= 8; } } else { /* clear padding */ memset(cp, 0, padlen); } /* packet_length includes payload, padding and padding length field */ - packet_length = buffer_len(&outgoing_packet) - 4; - ucp = (u_char *)buffer_ptr(&outgoing_packet); - PUT_32BIT(ucp, packet_length); - ucp[4] = padlen; + packet_length = buffer_len(&active_state->outgoing_packet) - 4; + cp = buffer_ptr(&active_state->outgoing_packet); + put_u32(cp, packet_length); + cp[4] = padlen; DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); /* compute MAC over seqnr and packet(length fields, payload, padding) */ if (mac && mac->enabled) { - macbuf = mac_compute(mac, seqnr, - (u_char *) buffer_ptr(&outgoing_packet), - buffer_len(&outgoing_packet)); - DBG(debug("done calc MAC out #%d", seqnr)); + macbuf = mac_compute(mac, active_state->p_send.seqnr, + buffer_ptr(&active_state->outgoing_packet), + buffer_len(&active_state->outgoing_packet)); + DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr)); } /* encrypt packet and append to output buffer. */ - buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); - cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), - buffer_len(&outgoing_packet)); + cp = buffer_append_space(&active_state->output, + buffer_len(&active_state->outgoing_packet)); + cipher_crypt(&active_state->send_context, cp, + buffer_ptr(&active_state->outgoing_packet), + buffer_len(&active_state->outgoing_packet)); /* append unencrypted MAC */ if (mac && mac->enabled) - buffer_append(&output, (char *)macbuf, mac->mac_len); + buffer_append(&active_state->output, macbuf, mac->mac_len); #ifdef PACKET_DEBUG fprintf(stderr, "encrypted: "); - buffer_dump(&output); + buffer_dump(&active_state->output); #endif /* increment sequence number for outgoing packets */ - if (++seqnr == 0) - log("outgoing seqnr wraps around"); - buffer_clear(&outgoing_packet); + if (++active_state->p_send.seqnr == 0) + logit("outgoing seqnr wraps around"); + if (++active_state->p_send.packets == 0) + if (!(datafellows & SSH_BUG_NOREKEY)) + fatal("XXX too many packets with same key"); + active_state->p_send.blocks += (packet_length + 4) / block_size; + active_state->p_send.bytes += packet_length + 4; + buffer_clear(&active_state->outgoing_packet); if (type == SSH2_MSG_NEWKEYS) set_newkeys(MODE_OUT); + else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side) + packet_enable_delayed_compress(); + return(packet_length); } -void -packet_send() +static int +packet_send2(void) +{ + static int packet_length = 0; + struct packet *p; + u_char type, *cp; + + cp = buffer_ptr(&active_state->outgoing_packet); + type = cp[5]; + + /* during rekeying we can only send key exchange messages */ + if (active_state->rekeying) { + if (!((type >= SSH2_MSG_TRANSPORT_MIN) && + (type <= SSH2_MSG_TRANSPORT_MAX))) { + debug("enqueue packet: %u", type); + p = xmalloc(sizeof(*p)); + p->type = type; + memcpy(&p->payload, &active_state->outgoing_packet, + sizeof(Buffer)); + buffer_init(&active_state->outgoing_packet); + TAILQ_INSERT_TAIL(&active_state->outgoing, p, next); + return(sizeof(Buffer)); + } + } + + /* rekeying starts with sending KEXINIT */ + if (type == SSH2_MSG_KEXINIT) + active_state->rekeying = 1; + + packet_length = packet_send2_wrapped(); + + /* after a NEWKEYS message we can send the complete queue */ + if (type == SSH2_MSG_NEWKEYS) { + active_state->rekeying = 0; + while ((p = TAILQ_FIRST(&active_state->outgoing))) { + type = p->type; + debug("dequeue packet: %u", type); + buffer_free(&active_state->outgoing_packet); + memcpy(&active_state->outgoing_packet, &p->payload, + sizeof(Buffer)); + TAILQ_REMOVE(&active_state->outgoing, p, next); + xfree(p); + packet_length += packet_send2_wrapped(); + } + } + return(packet_length); +} + +int +packet_send(void) { + int packet_len = 0; if (compat20) - packet_send2(); + packet_len = packet_send2(); else packet_send1(); DBG(debug("packet_send done")); + return(packet_len); } /* @@ -610,15 +1024,17 @@ packet_send() */ int -packet_read(int *payload_len_ptr) +packet_read_seqnr(u_int32_t *seqnr_p) { - int type, len; + int type, len, ret, ms_remain, cont; fd_set *setp; char buf[8192]; + struct timeval timeout, start, *timeoutp = NULL; + DBG(debug("packet_read()")); - setp = (fd_set *)xmalloc(howmany(connection_in+1, NFDBITS) * - sizeof(fd_mask)); + setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1, + NFDBITS), sizeof(fd_mask)); /* Since we are blocking, ensure that all written packets have been sent. */ packet_write_wait(); @@ -626,13 +1042,13 @@ packet_read(int *payload_len_ptr) /* Stay in the loop until we have received a complete packet. */ for (;;) { /* Try to read a packet from the buffer. */ - type = packet_read_poll(payload_len_ptr); + type = packet_read_poll_seqnr(seqnr_p); if (!compat20 && ( type == SSH_SMSG_SUCCESS || type == SSH_SMSG_FAILURE || type == SSH_CMSG_EOF || type == SSH_CMSG_EXIT_CONFIRMATION)) - packet_integrity_check(*payload_len_ptr, 0, type); + packet_check_eom(); /* If we got a packet, return it. */ if (type != SSH_MSG_NONE) { xfree(setp); @@ -642,20 +1058,48 @@ packet_read(int *payload_len_ptr) * Otherwise, wait for some data to arrive, add it to the * buffer, and try again. */ - memset(setp, 0, howmany(connection_in + 1, NFDBITS) * - sizeof(fd_mask)); - FD_SET(connection_in, setp); + memset(setp, 0, howmany(active_state->connection_in + 1, + NFDBITS) * sizeof(fd_mask)); + FD_SET(active_state->connection_in, setp); + if (active_state->packet_timeout_ms > 0) { + ms_remain = active_state->packet_timeout_ms; + timeoutp = &timeout; + } /* Wait for some data to arrive. */ - while (select(connection_in + 1, setp, NULL, NULL, NULL) == -1 && - (errno == EAGAIN || errno == EINTR)) - ; - + for (;;) { + if (active_state->packet_timeout_ms != -1) { + ms_to_timeval(&timeout, ms_remain); + gettimeofday(&start, NULL); + } + if ((ret = select(active_state->connection_in + 1, setp, + NULL, NULL, timeoutp)) >= 0) + break; + if (errno != EAGAIN && errno != EINTR && + errno != EWOULDBLOCK) + break; + if (active_state->packet_timeout_ms == -1) + continue; + ms_subtract_diff(&start, &ms_remain); + if (ms_remain <= 0) { + ret = 0; + break; + } + } + if (ret == 0) { + logit("Connection to %.200s timed out while " + "waiting to read", get_remote_ipaddr()); + cleanup_exit(255); + } /* Read data from the socket. */ - len = read(connection_in, buf, sizeof(buf)); + do { + cont = 0; + len = roaming_read(active_state->connection_in, buf, + sizeof(buf), &cont); + } while (len == 0 && cont); if (len == 0) { - log("Connection closed by %.200s", get_remote_ipaddr()); - fatal_cleanup(); + logit("Connection closed by %.200s", get_remote_ipaddr()); + cleanup_exit(255); } if (len < 0) fatal("Read from socket failed: %.100s", strerror(errno)); @@ -665,17 +1109,23 @@ packet_read(int *payload_len_ptr) /* NOTREACHED */ } +int +packet_read(void) +{ + return packet_read_seqnr(NULL); +} + /* * Waits until a packet has been received, verifies that its type matches * that given, and gives a fatal error and exits if there is a mismatch. */ void -packet_read_expect(int *payload_len_ptr, int expected_type) +packet_read_expect(int expected_type) { int type; - type = packet_read(payload_len_ptr); + type = packet_read(); if (type != expected_type) packet_disconnect("Protocol error: expected packet type %d, got %d", expected_type, type); @@ -688,220 +1138,266 @@ packet_read_expect(int *payload_len_ptr, int expected_type) * SSH_MSG_DISCONNECT is handled specially here. Also, * SSH_MSG_IGNORE messages are skipped by this function and are never returned * to higher levels. - * - * The returned payload_len does include space consumed by: - * Packet length - * Padding - * Packet type - * Check bytes */ static int -packet_read_poll1(int *payload_len_ptr) +packet_read_poll1(void) { u_int len, padded_len; - u_char *ucp, type; - char *cp; + u_char *cp, type; u_int checksum, stored_checksum; /* Check if input size is less than minimum packet size. */ - if (buffer_len(&input) < 4 + 8) + if (buffer_len(&active_state->input) < 4 + 8) return SSH_MSG_NONE; /* Get length of incoming packet. */ - ucp = (u_char *) buffer_ptr(&input); - len = GET_32BIT(ucp); + cp = buffer_ptr(&active_state->input); + len = get_u32(cp); if (len < 1 + 2 + 2 || len > 256 * 1024) - packet_disconnect("Bad packet length %d.", len); + packet_disconnect("Bad packet length %u.", len); padded_len = (len + 8) & ~7; /* Check if the packet has been entirely received. */ - if (buffer_len(&input) < 4 + padded_len) + if (buffer_len(&active_state->input) < 4 + padded_len) return SSH_MSG_NONE; /* The entire packet is in buffer. */ /* Consume packet length. */ - buffer_consume(&input, 4); + buffer_consume(&active_state->input, 4); /* * Cryptographic attack detector for ssh * (C)1998 CORE-SDI, Buenos Aires Argentina * Ariel Futoransky(futo@core-sdi.com) */ - if (receive_context.cipher->number != SSH_CIPHER_NONE && - detect_attack(buffer_ptr(&input), padded_len, NULL) == DEATTACK_DETECTED) - packet_disconnect("crc32 compensation attack: network attack detected"); + if (!active_state->receive_context.plaintext) { + switch (detect_attack(buffer_ptr(&active_state->input), + padded_len)) { + case DEATTACK_DETECTED: + packet_disconnect("crc32 compensation attack: " + "network attack detected"); + case DEATTACK_DOS_DETECTED: + packet_disconnect("deattack denial of " + "service detected"); + } + } /* Decrypt data to incoming_packet. */ - buffer_clear(&incoming_packet); - buffer_append_space(&incoming_packet, &cp, padded_len); - cipher_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len); + buffer_clear(&active_state->incoming_packet); + cp = buffer_append_space(&active_state->incoming_packet, padded_len); + cipher_crypt(&active_state->receive_context, cp, + buffer_ptr(&active_state->input), padded_len); - buffer_consume(&input, padded_len); + buffer_consume(&active_state->input, padded_len); #ifdef PACKET_DEBUG fprintf(stderr, "read_poll plain: "); - buffer_dump(&incoming_packet); + buffer_dump(&active_state->incoming_packet); #endif /* Compute packet checksum. */ - checksum = ssh_crc32((u_char *) buffer_ptr(&incoming_packet), - buffer_len(&incoming_packet) - 4); + checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet), + buffer_len(&active_state->incoming_packet) - 4); /* Skip padding. */ - buffer_consume(&incoming_packet, 8 - len % 8); + buffer_consume(&active_state->incoming_packet, 8 - len % 8); /* Test check bytes. */ - if (len != buffer_len(&incoming_packet)) - packet_disconnect("packet_read_poll: len %d != buffer_len %d.", - len, buffer_len(&incoming_packet)); + if (len != buffer_len(&active_state->incoming_packet)) + packet_disconnect("packet_read_poll1: len %d != buffer_len %d.", + len, buffer_len(&active_state->incoming_packet)); - ucp = (u_char *) buffer_ptr(&incoming_packet) + len - 4; - stored_checksum = GET_32BIT(ucp); + cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4; + stored_checksum = get_u32(cp); if (checksum != stored_checksum) packet_disconnect("Corrupted check bytes on input."); - buffer_consume_end(&incoming_packet, 4); - - if (packet_compression) { - buffer_clear(&compression_buffer); - buffer_uncompress(&incoming_packet, &compression_buffer); - buffer_clear(&incoming_packet); - buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), - buffer_len(&compression_buffer)); + buffer_consume_end(&active_state->incoming_packet, 4); + + if (active_state->packet_compression) { + buffer_clear(&active_state->compression_buffer); + buffer_uncompress(&active_state->incoming_packet, + &active_state->compression_buffer); + buffer_clear(&active_state->incoming_packet); + buffer_append(&active_state->incoming_packet, + buffer_ptr(&active_state->compression_buffer), + buffer_len(&active_state->compression_buffer)); } - type = buffer_get_char(&incoming_packet); - *payload_len_ptr = buffer_len(&incoming_packet); + active_state->p_read.packets++; + active_state->p_read.bytes += padded_len + 4; + type = buffer_get_char(&active_state->incoming_packet); + if (type < SSH_MSG_MIN || type > SSH_MSG_MAX) + packet_disconnect("Invalid ssh1 packet type: %d", type); return type; } static int -packet_read_poll2(int *payload_len_ptr) +packet_read_poll2(u_int32_t *seqnr_p) { - static u_int32_t seqnr = 0; - static u_int packet_length = 0; u_int padlen, need; - u_char *macbuf, *ucp, type; - char *cp; - int maclen, block_size; + u_char *macbuf, *cp, type; + u_int maclen, block_size; Enc *enc = NULL; Mac *mac = NULL; Comp *comp = NULL; - if (newkeys[MODE_IN] != NULL) { - enc = &newkeys[MODE_IN]->enc; - mac = &newkeys[MODE_IN]->mac; - comp = &newkeys[MODE_IN]->comp; + if (active_state->packet_discard) + return SSH_MSG_NONE; + + if (active_state->newkeys[MODE_IN] != NULL) { + enc = &active_state->newkeys[MODE_IN]->enc; + mac = &active_state->newkeys[MODE_IN]->mac; + comp = &active_state->newkeys[MODE_IN]->comp; } maclen = mac && mac->enabled ? mac->mac_len : 0; - block_size = enc ? enc->cipher->block_size : 8; + block_size = enc ? enc->block_size : 8; - if (packet_length == 0) { + if (active_state->packlen == 0) { /* * check if input size is less than the cipher block size, * decrypt first block and extract length of incoming packet */ - if (buffer_len(&input) < block_size) + if (buffer_len(&active_state->input) < block_size) return SSH_MSG_NONE; - buffer_clear(&incoming_packet); - buffer_append_space(&incoming_packet, &cp, block_size); - cipher_decrypt(&receive_context, cp, buffer_ptr(&input), + buffer_clear(&active_state->incoming_packet); + cp = buffer_append_space(&active_state->incoming_packet, block_size); - ucp = (u_char *) buffer_ptr(&incoming_packet); - packet_length = GET_32BIT(ucp); - if (packet_length < 1 + 4 || packet_length > 256 * 1024) { - buffer_dump(&incoming_packet); - packet_disconnect("Bad packet length %d.", packet_length); + cipher_crypt(&active_state->receive_context, cp, + buffer_ptr(&active_state->input), block_size); + cp = buffer_ptr(&active_state->incoming_packet); + active_state->packlen = get_u32(cp); + if (active_state->packlen < 1 + 4 || + active_state->packlen > PACKET_MAX_SIZE) { +#ifdef PACKET_DEBUG + buffer_dump(&active_state->incoming_packet); +#endif + logit("Bad packet length %u.", active_state->packlen); + packet_start_discard(enc, mac, active_state->packlen, + PACKET_MAX_SIZE); + return SSH_MSG_NONE; } - DBG(debug("input: packet len %d", packet_length+4)); - buffer_consume(&input, block_size); + DBG(debug("input: packet len %u", active_state->packlen+4)); + buffer_consume(&active_state->input, block_size); } /* we have a partial packet of block_size bytes */ - need = 4 + packet_length - block_size; + need = 4 + active_state->packlen - block_size; DBG(debug("partial packet %d, need %d, maclen %d", block_size, need, maclen)); - if (need % block_size != 0) - fatal("padding error: need %d block %d mod %d", + if (need % block_size != 0) { + logit("padding error: need %d block %d mod %d", need, block_size, need % block_size); + packet_start_discard(enc, mac, active_state->packlen, + PACKET_MAX_SIZE - block_size); + return SSH_MSG_NONE; + } /* * check if the entire packet has been received and * decrypt into incoming_packet */ - if (buffer_len(&input) < need + maclen) + if (buffer_len(&active_state->input) < need + maclen) return SSH_MSG_NONE; #ifdef PACKET_DEBUG fprintf(stderr, "read_poll enc/full: "); - buffer_dump(&input); + buffer_dump(&active_state->input); #endif - buffer_append_space(&incoming_packet, &cp, need); - cipher_decrypt(&receive_context, cp, buffer_ptr(&input), need); - buffer_consume(&input, need); + cp = buffer_append_space(&active_state->incoming_packet, need); + cipher_crypt(&active_state->receive_context, cp, + buffer_ptr(&active_state->input), need); + buffer_consume(&active_state->input, need); /* * compute MAC over seqnr and packet, * increment sequence number for incoming packet */ if (mac && mac->enabled) { - macbuf = mac_compute(mac, seqnr, - (u_char *) buffer_ptr(&incoming_packet), - buffer_len(&incoming_packet)); - if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) - packet_disconnect("Corrupted MAC on input."); - DBG(debug("MAC #%d ok", seqnr)); - buffer_consume(&input, mac->mac_len); + macbuf = mac_compute(mac, active_state->p_read.seqnr, + buffer_ptr(&active_state->incoming_packet), + buffer_len(&active_state->incoming_packet)); + if (memcmp(macbuf, buffer_ptr(&active_state->input), + mac->mac_len) != 0) { + logit("Corrupted MAC on input."); + if (need > PACKET_MAX_SIZE) + fatal("internal error need %d", need); + packet_start_discard(enc, mac, active_state->packlen, + PACKET_MAX_SIZE - need); + return SSH_MSG_NONE; + } + + DBG(debug("MAC #%d ok", active_state->p_read.seqnr)); + buffer_consume(&active_state->input, mac->mac_len); } - if (++seqnr == 0) - log("incoming seqnr wraps around"); + /* XXX now it's safe to use fatal/packet_disconnect */ + if (seqnr_p != NULL) + *seqnr_p = active_state->p_read.seqnr; + if (++active_state->p_read.seqnr == 0) + logit("incoming seqnr wraps around"); + if (++active_state->p_read.packets == 0) + if (!(datafellows & SSH_BUG_NOREKEY)) + fatal("XXX too many packets with same key"); + active_state->p_read.blocks += (active_state->packlen + 4) / block_size; + active_state->p_read.bytes += active_state->packlen + 4; /* get padlen */ - cp = buffer_ptr(&incoming_packet) + 4; - padlen = (u_char) *cp; + cp = buffer_ptr(&active_state->incoming_packet); + padlen = cp[4]; DBG(debug("input: padlen %d", padlen)); if (padlen < 4) packet_disconnect("Corrupted padlen %d on input.", padlen); /* skip packet size + padlen, discard padding */ - buffer_consume(&incoming_packet, 4 + 1); - buffer_consume_end(&incoming_packet, padlen); + buffer_consume(&active_state->incoming_packet, 4 + 1); + buffer_consume_end(&active_state->incoming_packet, padlen); - DBG(debug("input: len before de-compress %d", buffer_len(&incoming_packet))); + DBG(debug("input: len before de-compress %d", + buffer_len(&active_state->incoming_packet))); if (comp && comp->enabled) { - buffer_clear(&compression_buffer); - buffer_uncompress(&incoming_packet, &compression_buffer); - buffer_clear(&incoming_packet); - buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), - buffer_len(&compression_buffer)); - DBG(debug("input: len after de-compress %d", buffer_len(&incoming_packet))); + buffer_clear(&active_state->compression_buffer); + buffer_uncompress(&active_state->incoming_packet, + &active_state->compression_buffer); + buffer_clear(&active_state->incoming_packet); + buffer_append(&active_state->incoming_packet, + buffer_ptr(&active_state->compression_buffer), + buffer_len(&active_state->compression_buffer)); + DBG(debug("input: len after de-compress %d", + buffer_len(&active_state->incoming_packet))); } /* * get packet type, implies consume. * return length of payload (without type field) */ - type = buffer_get_char(&incoming_packet); + type = buffer_get_char(&active_state->incoming_packet); + if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN) + packet_disconnect("Invalid ssh2 packet type: %d", type); if (type == SSH2_MSG_NEWKEYS) set_newkeys(MODE_IN); - *payload_len_ptr = buffer_len(&incoming_packet); + else if (type == SSH2_MSG_USERAUTH_SUCCESS && + !active_state->server_side) + packet_enable_delayed_compress(); #ifdef PACKET_DEBUG fprintf(stderr, "read/plain[%d]:\r\n", type); - buffer_dump(&incoming_packet); + buffer_dump(&active_state->incoming_packet); #endif /* reset for next packet */ - packet_length = 0; + active_state->packlen = 0; return type; } int -packet_read_poll(int *payload_len_ptr) +packet_read_poll_seqnr(u_int32_t *seqnr_p) { - int reason; + u_int reason, seqnr; u_char type; char *msg; for (;;) { if (compat20) { - type = packet_read_poll2(payload_len_ptr); - if (type) + type = packet_read_poll2(seqnr_p); + if (type) { + active_state->keep_alive_timeouts = 0; DBG(debug("received packet type %d", type)); - switch(type) { + } + switch (type) { case SSH2_MSG_IGNORE: + debug3("Received SSH2_MSG_IGNORE"); break; case SSH2_MSG_DEBUG: packet_get_char(); @@ -914,18 +1410,22 @@ packet_read_poll(int *payload_len_ptr) case SSH2_MSG_DISCONNECT: reason = packet_get_int(); msg = packet_get_string(NULL); - log("Received disconnect from %s: %d: %.400s", get_remote_ipaddr(), - reason, msg); + logit("Received disconnect from %s: %u: %.400s", + get_remote_ipaddr(), reason, msg); xfree(msg); - fatal_cleanup(); + cleanup_exit(255); + break; + case SSH2_MSG_UNIMPLEMENTED: + seqnr = packet_get_int(); + debug("Received SSH2_MSG_UNIMPLEMENTED for %u", + seqnr); break; default: return type; - break; } } else { - type = packet_read_poll1(payload_len_ptr); - switch(type) { + type = packet_read_poll1(); + switch (type) { case SSH_MSG_IGNORE: break; case SSH_MSG_DEBUG: @@ -935,21 +1435,25 @@ packet_read_poll(int *payload_len_ptr) break; case SSH_MSG_DISCONNECT: msg = packet_get_string(NULL); - log("Received disconnect from %s: %.400s", get_remote_ipaddr(), - msg); - fatal_cleanup(); - xfree(msg); + logit("Received disconnect from %s: %.400s", + get_remote_ipaddr(), msg); + cleanup_exit(255); break; default: if (type) DBG(debug("received packet type %d", type)); return type; - break; } } } } +int +packet_read_poll(void) +{ + return packet_read_poll_seqnr(NULL); +} + /* * Buffers the given amount of input characters. This is intended to be used * together with packet_read_poll. @@ -958,25 +1462,41 @@ packet_read_poll(int *payload_len_ptr) void packet_process_incoming(const char *buf, u_int len) { - buffer_append(&input, buf, len); + if (active_state->packet_discard) { + active_state->keep_alive_timeouts = 0; /* ?? */ + if (len >= active_state->packet_discard) + packet_stop_discard(); + active_state->packet_discard -= len; + return; + } + buffer_append(&active_state->input, buf, len); } /* Returns a character from the packet. */ u_int -packet_get_char() +packet_get_char(void) { char ch; - buffer_get(&incoming_packet, &ch, 1); + + buffer_get(&active_state->incoming_packet, &ch, 1); return (u_char) ch; } /* Returns an integer from the packet data. */ u_int -packet_get_int() +packet_get_int(void) +{ + return buffer_get_int(&active_state->incoming_packet); +} + +/* Returns an 64 bit integer from the packet data. */ + +u_int64_t +packet_get_int64(void) { - return buffer_get_int(&incoming_packet); + return buffer_get_int64(&active_state->incoming_packet); } /* @@ -985,30 +1505,31 @@ packet_get_int() */ void -packet_get_bignum(BIGNUM * value, int *length_ptr) +packet_get_bignum(BIGNUM * value) { - *length_ptr = buffer_get_bignum(&incoming_packet, value); + buffer_get_bignum(&active_state->incoming_packet, value); } void -packet_get_bignum2(BIGNUM * value, int *length_ptr) +packet_get_bignum2(BIGNUM * value) { - *length_ptr = buffer_get_bignum2(&incoming_packet, value); + buffer_get_bignum2(&active_state->incoming_packet, value); } -char * -packet_get_raw(int *length_ptr) +void * +packet_get_raw(u_int *length_ptr) { - int bytes = buffer_len(&incoming_packet); + u_int bytes = buffer_len(&active_state->incoming_packet); + if (length_ptr != NULL) *length_ptr = bytes; - return buffer_ptr(&incoming_packet); + return buffer_ptr(&active_state->incoming_packet); } int packet_remaining(void) { - return buffer_len(&incoming_packet); + return buffer_len(&active_state->incoming_packet); } /* @@ -1018,20 +1539,17 @@ packet_remaining(void) * integer into which the length of the string is stored. */ -char * +void * packet_get_string(u_int *length_ptr) { - return buffer_get_string(&incoming_packet, length_ptr); + return buffer_get_string(&active_state->incoming_packet, length_ptr); } -/*modified by binhe*/ -/* Clears incoming data buffer */ - -void packet_get_all(void) +void * +packet_get_string_ptr(u_int *length_ptr) { - buffer_clear(&incoming_packet); + return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr); } -/*end of modification*/ /* * Sends a diagnostic message from the server to the client. This message @@ -1081,6 +1599,7 @@ packet_disconnect(const char *fmt,...) char buf[1024]; va_list args; static int disconnecting = 0; + if (disconnecting) /* Guard against recursive invocations. */ fatal("packet_disconnect called recursively."); disconnecting = 1; @@ -1093,6 +1612,9 @@ packet_disconnect(const char *fmt,...) vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); + /* Display the error locally */ + logit("Disconnecting: %.100s", buf); + /* Send the disconnect message to the other side, and wait for it to get sent. */ if (compat20) { packet_start(SSH2_MSG_DISCONNECT); @@ -1111,28 +1633,34 @@ packet_disconnect(const char *fmt,...) /* Close the connection. */ packet_close(); - - /* Display the error locally and exit. */ - log("Disconnecting: %.100s", buf); - fatal_cleanup(); + cleanup_exit(255); } /* Checks if there is any buffered output, and tries to write some of the output. */ -void -packet_write_poll() +int +packet_write_poll(void) { - int len = buffer_len(&output); + int len = 0; + int cont; + + len = buffer_len(&active_state->output); + if (len > 0) { - len = write(connection_out, buffer_ptr(&output), len); - if (len <= 0) { - if (errno == EAGAIN) - return; - else - fatal("Write failed: %.100s", strerror(errno)); + cont = 0; + len = roaming_write(active_state->connection_out, + buffer_ptr(&active_state->output), len, &cont); + if (len == -1) { + if (errno == EINTR || errno == EAGAIN || + errno == EWOULDBLOCK) + return (0); + fatal("Write failed: %.100s", strerror(errno)); } - buffer_consume(&output, len); + if (len == 0 && !cont) + fatal("Write connection closed"); + buffer_consume(&active_state->output, len); } + return(len); } /* @@ -1140,43 +1668,89 @@ packet_write_poll() * written. */ -void -packet_write_wait() +int +packet_write_wait(void) { fd_set *setp; + int ret, ms_remain; + struct timeval start, timeout, *timeoutp = NULL; + u_int bytes_sent = 0; - setp = (fd_set *)xmalloc(howmany(connection_out + 1, NFDBITS) * - sizeof(fd_mask)); - packet_write_poll(); + setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1, + NFDBITS), sizeof(fd_mask)); + bytes_sent += packet_write_poll(); while (packet_have_data_to_write()) { - memset(setp, 0, howmany(connection_out + 1, NFDBITS) * - sizeof(fd_mask)); - FD_SET(connection_out, setp); - while (select(connection_out + 1, NULL, setp, NULL, NULL) == -1 && - (errno == EAGAIN || errno == EINTR)) - ; - packet_write_poll(); + memset(setp, 0, howmany(active_state->connection_out + 1, + NFDBITS) * sizeof(fd_mask)); + FD_SET(active_state->connection_out, setp); + + if (active_state->packet_timeout_ms > 0) { + ms_remain = active_state->packet_timeout_ms; + timeoutp = &timeout; + } + for (;;) { + if (active_state->packet_timeout_ms != -1) { + ms_to_timeval(&timeout, ms_remain); + gettimeofday(&start, NULL); + } + if ((ret = select(active_state->connection_out + 1, + NULL, setp, NULL, timeoutp)) >= 0) + break; + if (errno != EAGAIN && errno != EINTR && + errno != EWOULDBLOCK) + break; + if (active_state->packet_timeout_ms == -1) + continue; + ms_subtract_diff(&start, &ms_remain); + if (ms_remain <= 0) { + ret = 0; + break; + } + } + if (ret == 0) { + logit("Connection to %.200s timed out while " + "waiting to write", get_remote_ipaddr()); + cleanup_exit(255); + } + bytes_sent += packet_write_poll(); } xfree(setp); + return (bytes_sent); } /* Returns true if there is buffered data to write to the connection. */ int -packet_have_data_to_write() +packet_have_data_to_write(void) { - return buffer_len(&output) != 0; + return buffer_len(&active_state->output) != 0; } /* Returns true if there is not too much data to write to the connection. */ int -packet_not_very_much_data_to_write() +packet_not_very_much_data_to_write(void) { - if (interactive_mode) - return buffer_len(&output) < 16384; + if (active_state->interactive_mode) + return buffer_len(&active_state->output) < 16384; else - return buffer_len(&output) < 128 * 1024; + return buffer_len(&active_state->output) < 128 * 1024; +} + +static void +packet_set_tos(int interactive) +{ +#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) + int tos = interactive ? IPTOS_LOWDELAY : IPTOS_THROUGHPUT; + + if (!packet_connection_is_on_socket() || + !packet_connection_is_ipv4()) + return; + if (setsockopt(active_state->connection_in, IPPROTO_IP, IP_TOS, &tos, + sizeof(tos)) < 0) + error("setsockopt IP_TOS %d: %.100s:", + tos, strerror(errno)); +#endif } /* Informs that the current session is interactive. Sets IP flags for that. */ @@ -1184,87 +1758,69 @@ packet_not_very_much_data_to_write() void packet_set_interactive(int interactive) { - static int called = 0; -#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) - int lowdelay = IPTOS_LOWDELAY; - int throughput = IPTOS_THROUGHPUT; -#endif - int on = 1; - - if (called) + if (active_state->set_interactive_called) return; - called = 1; + active_state->set_interactive_called = 1; /* Record that we are in interactive mode. */ - interactive_mode = interactive; + active_state->interactive_mode = interactive; /* Only set socket options if using a socket. */ if (!packet_connection_is_on_socket()) return; - /* - * IPTOS_LOWDELAY and IPTOS_THROUGHPUT are IPv4 only - */ - if (interactive) { - /* - * Set IP options for an interactive connection. Use - * IPTOS_LOWDELAY and TCP_NODELAY. - */ -#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) - if (packet_connection_is_ipv4()) { - if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, - (void *) &lowdelay, sizeof(lowdelay)) < 0) - error("setsockopt IPTOS_LOWDELAY: %.100s", - strerror(errno)); - } -#endif - if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on, - sizeof(on)) < 0) - error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); - } else if (packet_connection_is_ipv4()) { - /* - * Set IP options for a non-interactive connection. Use - * IPTOS_THROUGHPUT. - */ -#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) - if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput, - sizeof(throughput)) < 0) - error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno)); -#endif - } + set_nodelay(active_state->connection_in); + packet_set_tos(interactive); } /* Returns true if the current connection is interactive. */ int -packet_is_interactive() +packet_is_interactive(void) { - return interactive_mode; + return active_state->interactive_mode; } int -packet_set_maxsize(int s) +packet_set_maxsize(u_int s) { - static int called = 0; - if (called) { - log("packet_set_maxsize: called twice: old %d new %d", - max_packet_size, s); + if (active_state->set_maxsize_called) { + logit("packet_set_maxsize: called twice: old %d new %d", + active_state->max_packet_size, s); return -1; } if (s < 4 * 1024 || s > 1024 * 1024) { - log("packet_set_maxsize: bad size %d", s); + logit("packet_set_maxsize: bad size %d", s); return -1; } - called = 1; + active_state->set_maxsize_called = 1; debug("packet_set_maxsize: setting to %d", s); - max_packet_size = s; + active_state->max_packet_size = s; return s; } +int +packet_inc_alive_timeouts(void) +{ + return ++active_state->keep_alive_timeouts; +} + +void +packet_set_alive_timeouts(int ka) +{ + active_state->keep_alive_timeouts = ka; +} + +u_int +packet_get_maxsize(void) +{ + return active_state->max_packet_size; +} + /* roundup current message to pad bytes */ void packet_add_padding(u_char pad) { - extra_pad = pad; + active_state->extra_pad = pad; } /* @@ -1281,15 +1837,131 @@ packet_add_padding(u_char pad) void packet_send_ignore(int nbytes) { - u_int32_t rand = 0; + u_int32_t rnd = 0; int i; packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE); packet_put_int(nbytes); - for(i = 0; i < nbytes; i++) { + for (i = 0; i < nbytes; i++) { if (i % 4 == 0) - rand = arc4random(); - packet_put_char(rand & 0xff); - rand >>= 8; + rnd = arc4random(); + packet_put_char((u_char)rnd & 0xff); + rnd >>= 8; + } +} + +int rekey_requested = 0; +void +packet_request_rekeying(void) +{ + rekey_requested = 1; +} + +#define MAX_PACKETS (1U<<31) +int +packet_need_rekeying(void) +{ + if (datafellows & SSH_BUG_NOREKEY) + return 0; + if (rekey_requested == 1) + { + rekey_requested = 0; + return 1; + } + return + (active_state->p_send.packets > MAX_PACKETS) || + (active_state->p_read.packets > MAX_PACKETS) || + (active_state->max_blocks_out && + (active_state->p_send.blocks > active_state->max_blocks_out)) || + (active_state->max_blocks_in && + (active_state->p_read.blocks > active_state->max_blocks_in)); +} + +void +packet_set_rekey_limit(u_int32_t bytes) +{ + active_state->rekey_limit = bytes; +} + +void +packet_set_server(void) +{ + active_state->server_side = 1; +} + +void +packet_set_authenticated(void) +{ + active_state->after_authentication = 1; +} + +void * +packet_get_input(void) +{ + return (void *)&active_state->input; +} + +void * +packet_get_output(void) +{ + return (void *)&active_state->output; +} + +void * +packet_get_newkeys(int mode) +{ + return (void *)active_state->newkeys[mode]; +} + +/* + * Save the state for the real connection, and use a separate state when + * resuming a suspended connection. + */ +void +packet_backup_state(void) +{ + struct session_state *tmp; + + close(active_state->connection_in); + active_state->connection_in = -1; + close(active_state->connection_out); + active_state->connection_out = -1; + if (backup_state) + tmp = backup_state; + else + tmp = alloc_session_state(); + backup_state = active_state; + active_state = tmp; +} + +/* + * Swap in the old state when resuming a connecion. + */ +void +packet_restore_state(void) +{ + struct session_state *tmp; + void *buf; + u_int len; + + tmp = backup_state; + backup_state = active_state; + active_state = tmp; + active_state->connection_in = backup_state->connection_in; + backup_state->connection_in = -1; + active_state->connection_out = backup_state->connection_out; + backup_state->connection_out = -1; + len = buffer_len(&backup_state->input); + if (len > 0) { + buf = buffer_ptr(&backup_state->input); + buffer_append(&active_state->input, buf, len); + buffer_clear(&backup_state->input); + add_recv_bytes(len); } } + +int +packet_authentication_state(void) +{ + return(active_state->after_authentication); +}