X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/bfe4994432b3a30a7e74fbf531d4e54ab7a3c228..5262cbfbbd270876de2cd547ff0032d85b1d2640:/openssh/packet.c diff --git a/openssh/packet.c b/openssh/packet.c index 23b5b71..7b77e29 100644 --- a/openssh/packet.c +++ b/openssh/packet.c @@ -1,3 +1,4 @@ +/* $OpenBSD: packet.c,v 1.160 2009/02/13 11:50:21 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -37,24 +38,39 @@ */ #include "includes.h" -RCSID("$OpenBSD: packet.c,v 1.104 2003/04/01 10:22:21 markus Exp $"); + +#include +#include "openbsd-compat/sys-queue.h" +#include +#include +#ifdef HAVE_SYS_TIME_H +# include +#endif + +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include #include "xmalloc.h" #include "buffer.h" #include "packet.h" -#include "bufaux.h" #include "crc32.h" -#include "getput.h" - #include "compress.h" #include "deattack.h" #include "channels.h" - #include "compat.h" #include "ssh1.h" #include "ssh2.h" - #include "cipher.h" +#include "key.h" #include "kex.h" #include "mac.h" #include "log.h" @@ -68,6 +84,8 @@ RCSID("$OpenBSD: packet.c,v 1.104 2003/04/01 10:22:21 markus Exp $"); #define DBG(x) #endif +#define PACKET_MAX_SIZE (256 * 1024) + /* * This variable contains the file descriptors used for communicating with * the other side. connection_in is used for reading; connection_out for @@ -106,7 +124,7 @@ static int compression_buffer_ready = 0; static int packet_compression = 0; /* default maximum packet size */ -int max_packet_size = 32768; +u_int max_packet_size = 32768; /* Flag indicating whether this module has been initialized. */ static int initialized = 0; @@ -114,10 +132,28 @@ static int initialized = 0; /* Set to true if the connection is interactive. */ static int interactive_mode = 0; +/* Set to true if we are the server side. */ +static int server_side = 0; + +/* Set to true if we are authenticated. */ +static int after_authentication = 0; + +int keep_alive_timeouts = 0; + +/* Set to the maximum time that we will wait to send or receive a packet */ +static int packet_timeout_ms = -1; + /* Session key information for Encryption and MAC */ Newkeys *newkeys[MODE_MAX]; -static u_int32_t read_seqnr = 0; -static u_int32_t send_seqnr = 0; +static struct packet_state { + u_int32_t seqnr; + u_int32_t packets; + u_int64_t blocks; + u_int64_t bytes; +} p_read, p_send; + +static u_int64_t max_blocks_in, max_blocks_out; +static u_int32_t rekey_limit; /* Session key for protocol v1 */ static u_char ssh1_key[SSH_SESSION_KEY_LENGTH]; @@ -126,6 +162,17 @@ static u_int ssh1_keylen; /* roundup current message to extra_pad bytes */ static u_char extra_pad = 0; +/* XXX discard incoming data after MAC error */ +static u_int packet_discard = 0; +static Mac *packet_discard_mac = NULL; + +struct packet { + TAILQ_ENTRY(packet) next; + u_char type; + Buffer payload; +}; +TAILQ_HEAD(, packet) outgoing; + /* * Sets the descriptors used for communication. Disables encryption until * packet_set_encryption_key is called. @@ -139,8 +186,10 @@ packet_set_connection(int fd_in, int fd_out) fatal("packet_set_connection: cannot load cipher 'none'"); connection_in = fd_in; connection_out = fd_out; - cipher_init(&send_context, none, "", 0, NULL, 0, CIPHER_ENCRYPT); - cipher_init(&receive_context, none, "", 0, NULL, 0, CIPHER_DECRYPT); + cipher_init(&send_context, none, (const u_char *)"", + 0, NULL, 0, CIPHER_ENCRYPT); + cipher_init(&receive_context, none, (const u_char *)"", + 0, NULL, 0, CIPHER_DECRYPT); newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL; if (!initialized) { initialized = 1; @@ -148,9 +197,52 @@ packet_set_connection(int fd_in, int fd_out) buffer_init(&output); buffer_init(&outgoing_packet); buffer_init(&incoming_packet); + TAILQ_INIT(&outgoing); + p_send.packets = 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) { + packet_timeout_ms = -1; + return; + } + if ((INT_MAX / 1000) / count < timeout) + packet_timeout_ms = INT_MAX; + else + packet_timeout_ms = timeout * count * 1000; +} + +static void +packet_stop_discard(void) +{ + if (packet_discard_mac) { + char buf[1024]; + + memset(buf, 'a', sizeof(buf)); + while (buffer_len(&incoming_packet) < PACKET_MAX_SIZE) + buffer_append(&incoming_packet, buf, sizeof(buf)); + (void) mac_compute(packet_discard_mac, + p_read.seqnr, + buffer_ptr(&incoming_packet), + PACKET_MAX_SIZE); + } + logit("Finished discarding for %.200s", get_remote_ipaddr()); + cleanup_exit(255); +} + +static void +packet_start_discard(Enc *enc, Mac *mac, u_int packet_length, u_int discard) +{ + if (enc == NULL || !cipher_is_cbc(enc->cipher)) + packet_disconnect("Packet corrupt"); + if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled) + packet_discard_mac = mac; + if (buffer_len(&input) >= discard) + packet_stop_discard(); + packet_discard = discard - buffer_len(&input); } /* Returns 1 if remote host is connected via socket, 0 if not. */ @@ -236,6 +328,7 @@ packet_get_keyiv_len(int mode) return (cipher_get_keyiv_len(cc)); } + void packet_set_iv(int mode, u_char *dat) { @@ -248,28 +341,41 @@ packet_set_iv(int mode, u_char *dat) cipher_set_keyiv(cc, dat); } + int -packet_get_ssh1_cipher() +packet_get_ssh1_cipher(void) { return (cipher_get_number(receive_context.cipher)); } - -u_int32_t -packet_get_seqnr(int mode) +void +packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks, u_int32_t *packets, + u_int64_t *bytes) { - return (mode == MODE_IN ? read_seqnr : send_seqnr); + struct packet_state *state; + + state = (mode == MODE_IN) ? &p_read : &p_send; + if (seqnr) + *seqnr = state->seqnr; + if (blocks) + *blocks = state->blocks; + if (packets) + *packets = state->packets; + if (bytes) + *bytes = state->bytes; } void -packet_set_seqnr(int mode, u_int32_t seqnr) +packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets, + u_int64_t bytes) { - if (mode == MODE_IN) - read_seqnr = seqnr; - else if (mode == MODE_OUT) - send_seqnr = seqnr; - else - fatal("packet_set_seqnr: bad mode %d", mode); + struct packet_state *state; + + state = (mode == MODE_IN) ? &p_read : &p_send; + state->seqnr = seqnr; + state->blocks = blocks; + state->packets = packets; + state->bytes = bytes; } /* returns 1 if connection is via ipv4 */ @@ -286,7 +392,7 @@ packet_connection_is_ipv4(void) if (to.ss_family == AF_INET) return 1; #ifdef IPV4_IN_IPV6 - if (to.ss_family == AF_INET6 && + if (to.ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr)) return 1; #endif @@ -299,13 +405,10 @@ void packet_set_nonblocking(void) { /* Set the socket into non-blocking mode. */ - if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0) - error("fcntl O_NONBLOCK: %.100s", strerror(errno)); + set_nonblock(connection_in); - if (connection_out != connection_in) { - if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0) - error("fcntl O_NONBLOCK: %.100s", strerror(errno)); - } + if (connection_out != connection_in) + set_nonblock(connection_out); } /* Returns the socket used for reading. */ @@ -448,31 +551,37 @@ packet_put_char(int value) buffer_append(&outgoing_packet, &ch, 1); } + void packet_put_int(u_int value) { buffer_put_int(&outgoing_packet, value); } + void packet_put_string(const void *buf, u_int len) { buffer_put_string(&outgoing_packet, buf, len); } + void packet_put_cstring(const char *str) { buffer_put_cstring(&outgoing_packet, str); } + void packet_put_raw(const void *buf, u_int len) { buffer_append(&outgoing_packet, buf, len); } + void packet_put_bignum(BIGNUM * value) { buffer_put_bignum(&outgoing_packet, value); } + void packet_put_bignum2(BIGNUM * value) { @@ -490,7 +599,7 @@ packet_send1(void) 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 @@ -516,9 +625,9 @@ packet_send1(void) cp = buffer_ptr(&outgoing_packet); for (i = 0; i < padding; i++) { if (i % 4 == 0) - rand = arc4random(); - cp[7 - i] = rand & 0xff; - rand >>= 8; + rnd = arc4random(); + cp[7 - i] = rnd & 0xff; + rnd >>= 8; } } buffer_consume(&outgoing_packet, 8 - padding); @@ -526,7 +635,7 @@ packet_send1(void) /* Add check bytes. */ checksum = ssh_crc32(buffer_ptr(&outgoing_packet), buffer_len(&outgoing_packet)); - PUT_32BIT(buf, checksum); + put_u32(buf, checksum); buffer_append(&outgoing_packet, buf, 4); #ifdef PACKET_DEBUG @@ -535,7 +644,7 @@ packet_send1(void) #endif /* Append to output. */ - PUT_32BIT(buf, len); + put_u32(buf, len); buffer_append(&output, buf, 4); cp = buffer_append_space(&output, buffer_len(&outgoing_packet)); cipher_crypt(&send_context, cp, buffer_ptr(&outgoing_packet), @@ -545,11 +654,12 @@ packet_send1(void) fprintf(stderr, "encrypted: "); buffer_dump(&output); #endif - + p_send.packets++; + p_send.bytes += len + buffer_len(&outgoing_packet); buffer_clear(&outgoing_packet); /* - * Note that the packet is now only buffered in output. It won\'t be + * Note that the packet is now only buffered in output. It won't be * actually sent until packet_write_wait or packet_write_poll is * called. */ @@ -562,16 +672,21 @@ set_newkeys(int mode) Mac *mac; Comp *comp; CipherContext *cc; - int encrypt; + u_int64_t *max_blocks; + int crypt_type; debug2("set_newkeys: mode %d", mode); if (mode == MODE_OUT) { cc = &send_context; - encrypt = CIPHER_ENCRYPT; + crypt_type = CIPHER_ENCRYPT; + p_send.packets = p_send.blocks = 0; + max_blocks = &max_blocks_out; } else { cc = &receive_context; - encrypt = CIPHER_DECRYPT; + crypt_type = CIPHER_DECRYPT; + p_read.packets = p_read.blocks = 0; + max_blocks = &max_blocks_in; } if (newkeys[mode] != NULL) { debug("set_newkeys: rekeying"); @@ -579,7 +694,7 @@ set_newkeys(int mode) enc = &newkeys[mode]->enc; mac = &newkeys[mode]->mac; comp = &newkeys[mode]->comp; - memset(mac->key, 0, mac->key_len); + mac_clear(mac); xfree(enc->name); xfree(enc->iv); xfree(enc->key); @@ -594,15 +709,18 @@ set_newkeys(int mode) enc = &newkeys[mode]->enc; mac = &newkeys[mode]->mac; comp = &newkeys[mode]->comp; - if (mac->md != NULL) + if (mac_init(mac) == 0) mac->enabled = 1; DBG(debug("cipher_init_context: %d", mode)); cipher_init(cc, enc->cipher, enc->key, enc->key_len, - enc->iv, enc->block_size, encrypt); + enc->iv, enc->block_size, crypt_type); /* Deleting the keys does not gain extra security */ /* memset(enc->iv, 0, enc->block_size); - memset(enc->key, 0, enc->key_len); */ - if (comp->type != 0 && comp->enabled == 0) { + memset(enc->key, 0, enc->key_len); + memset(mac->key, 0, mac->key_len); */ + if ((comp->type == COMP_ZLIB || + (comp->type == COMP_DELAYED && after_authentication)) && + comp->enabled == 0) { packet_init_compression(); if (mode == MODE_OUT) buffer_compress_init_send(6); @@ -610,19 +728,61 @@ 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 (rekey_limit) + *max_blocks = MIN(*max_blocks, rekey_limit / enc->block_size); } /* - * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) + * Delayed compression for SSH2 is enabled after authentication: + * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent, + * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received. */ static void -packet_send2(void) +packet_enable_delayed_compress(void) +{ + Comp *comp = NULL; + int mode; + + /* + * Remember that we are past the authentication step, so rekeying + * with COMP_DELAYED will turn on compression immediately. + */ + after_authentication = 1; + for (mode = 0; mode < MODE_MAX; mode++) { + /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */ + if (newkeys[mode] == NULL) + continue; + comp = &newkeys[mode]->comp; + if (comp && !comp->enabled && comp->type == COMP_DELAYED) { + packet_init_compression(); + if (mode == MODE_OUT) + buffer_compress_init_send(6); + else + buffer_compress_init_recv(); + comp->enabled = 1; + } + } +} + +/* + * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) + */ +static int +packet_send2_wrapped(void) { u_char type, *cp, *macbuf = NULL; u_char padlen, pad; u_int packet_length = 0; u_int i, len; - u_int32_t rand = 0; + u_int32_t rnd = 0; Enc *enc = NULL; Mac *mac = NULL; Comp *comp = NULL; @@ -681,9 +841,9 @@ packet_send2(void) /* 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 */ @@ -692,16 +852,16 @@ packet_send2(void) /* packet_length includes payload, padding and padding length field */ packet_length = buffer_len(&outgoing_packet) - 4; cp = buffer_ptr(&outgoing_packet); - PUT_32BIT(cp, packet_length); + put_u32(cp, packet_length); cp[4] = padlen; DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); /* compute MAC over seqnr and packet(length fields, payload, padding) */ if (mac && mac->enabled) { - macbuf = mac_compute(mac, send_seqnr, + macbuf = mac_compute(mac, p_send.seqnr, buffer_ptr(&outgoing_packet), buffer_len(&outgoing_packet)); - DBG(debug("done calc MAC out #%d", send_seqnr)); + DBG(debug("done calc MAC out #%d", p_send.seqnr)); } /* encrypt packet and append to output buffer. */ cp = buffer_append_space(&output, buffer_len(&outgoing_packet)); @@ -709,28 +869,86 @@ packet_send2(void) buffer_len(&outgoing_packet)); /* append unencrypted MAC */ if (mac && mac->enabled) - buffer_append(&output, (char *)macbuf, mac->mac_len); + buffer_append(&output, macbuf, mac->mac_len); #ifdef PACKET_DEBUG fprintf(stderr, "encrypted: "); buffer_dump(&output); #endif /* increment sequence number for outgoing packets */ - if (++send_seqnr == 0) - log("outgoing seqnr wraps around"); + if (++p_send.seqnr == 0) + logit("outgoing seqnr wraps around"); + if (++p_send.packets == 0) + if (!(datafellows & SSH_BUG_NOREKEY)) + fatal("XXX too many packets with same key"); + p_send.blocks += (packet_length + 4) / block_size; + p_send.bytes += packet_length + 4; buffer_clear(&outgoing_packet); if (type == SSH2_MSG_NEWKEYS) set_newkeys(MODE_OUT); + else if (type == SSH2_MSG_USERAUTH_SUCCESS && server_side) + packet_enable_delayed_compress(); + return(packet_length); } -void +static int +packet_send2(void) +{ + static int packet_length = 0; + static int rekeying = 0; + struct packet *p; + u_char type, *cp; + + cp = buffer_ptr(&outgoing_packet); + type = cp[5]; + + /* during rekeying we can only send key exchange messages */ + if (rekeying) { + if (!((type >= SSH2_MSG_TRANSPORT_MIN) && + (type <= SSH2_MSG_TRANSPORT_MAX))) { + debug("enqueue packet: %u", type); + p = xmalloc(sizeof(*p)); + p->type = type; + memcpy(&p->payload, &outgoing_packet, sizeof(Buffer)); + buffer_init(&outgoing_packet); + TAILQ_INSERT_TAIL(&outgoing, p, next); + return(sizeof(Buffer)); + } + } + + /* rekeying starts with sending KEXINIT */ + if (type == SSH2_MSG_KEXINIT) + rekeying = 1; + + packet_length = packet_send2_wrapped(); + + /* after a NEWKEYS message we can send the complete queue */ + if (type == SSH2_MSG_NEWKEYS) { + rekeying = 0; + while ((p = TAILQ_FIRST(&outgoing))) { + type = p->type; + debug("dequeue packet: %u", type); + buffer_free(&outgoing_packet); + memcpy(&outgoing_packet, &p->payload, + sizeof(Buffer)); + TAILQ_REMOVE(&outgoing, p, next); + xfree(p); + packet_length += packet_send2_wrapped(); + } + } + return(packet_length); +} + +int packet_send(void) { + int packet_len = 0; if (compat20) - packet_send2(); + packet_len = packet_send2(); else packet_send1(); DBG(debug("packet_send done")); + return(packet_len); } /* @@ -742,12 +960,14 @@ packet_send(void) int packet_read_seqnr(u_int32_t *seqnr_p) { - int type, len; + int type, len, ret, ms_remain; fd_set *setp; char buf[8192]; + struct timeval timeout, start, *timeoutp = NULL; + DBG(debug("packet_read()")); - setp = (fd_set *)xmalloc(howmany(connection_in+1, NFDBITS) * + setp = (fd_set *)xcalloc(howmany(connection_in+1, NFDBITS), sizeof(fd_mask)); /* Since we are blocking, ensure that all written packets have been sent. */ @@ -776,16 +996,40 @@ packet_read_seqnr(u_int32_t *seqnr_p) sizeof(fd_mask)); FD_SET(connection_in, setp); + if (packet_timeout_ms > 0) { + ms_remain = packet_timeout_ms; + timeoutp = &timeout; + } /* Wait for some data to arrive. */ - while (select(connection_in + 1, setp, NULL, NULL, NULL) == -1 && - (errno == EAGAIN || errno == EINTR)) - ; - + for (;;) { + if (packet_timeout_ms != -1) { + ms_to_timeval(&timeout, ms_remain); + gettimeofday(&start, NULL); + } + if ((ret = select(connection_in + 1, setp, NULL, + NULL, timeoutp)) >= 0) + break; + if (errno != EAGAIN && errno != EINTR && + errno != EWOULDBLOCK) + break; + if (packet_timeout_ms == -1) + continue; + ms_subtract_diff(&start, &ms_remain); + if (ms_remain <= 0) { + ret = 0; + break; + } + } + if (ret == 0) { + logit("Connection to %.200s timed out while " + "waiting to read", get_remote_ipaddr()); + cleanup_exit(255); + } /* Read data from the socket. */ len = read(connection_in, buf, sizeof(buf)); if (len == 0) { - log("Connection closed by %.200s", get_remote_ipaddr()); - fatal_cleanup(); + logit("Connection closed by %.200s", get_remote_ipaddr()); + cleanup_exit(255); } if (len < 0) fatal("Read from socket failed: %.100s", strerror(errno)); @@ -838,7 +1082,7 @@ packet_read_poll1(void) return SSH_MSG_NONE; /* Get length of incoming packet. */ cp = buffer_ptr(&input); - len = GET_32BIT(cp); + len = get_u32(cp); if (len < 1 + 2 + 2 || len > 256 * 1024) packet_disconnect("Bad packet length %u.", len); padded_len = (len + 8) & ~7; @@ -857,9 +1101,16 @@ packet_read_poll1(void) * (C)1998 CORE-SDI, Buenos Aires Argentina * Ariel Futoransky(futo@core-sdi.com) */ - if (!receive_context.plaintext && - detect_attack(buffer_ptr(&input), padded_len, NULL) == DEATTACK_DETECTED) - packet_disconnect("crc32 compensation attack: network attack detected"); + if (!receive_context.plaintext) { + switch (detect_attack(buffer_ptr(&input), padded_len)) { + case DEATTACK_DETECTED: + packet_disconnect("crc32 compensation attack: " + "network attack detected"); + case DEATTACK_DOS_DETECTED: + packet_disconnect("deattack denial of " + "service detected"); + } + } /* Decrypt data to incoming_packet. */ buffer_clear(&incoming_packet); @@ -886,7 +1137,7 @@ packet_read_poll1(void) len, buffer_len(&incoming_packet)); cp = (u_char *)buffer_ptr(&incoming_packet) + len - 4; - stored_checksum = GET_32BIT(cp); + stored_checksum = get_u32(cp); if (checksum != stored_checksum) packet_disconnect("Corrupted check bytes on input."); buffer_consume_end(&incoming_packet, 4); @@ -898,7 +1149,11 @@ packet_read_poll1(void) buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), buffer_len(&compression_buffer)); } + p_read.packets++; + p_read.bytes += padded_len + 4; type = buffer_get_char(&incoming_packet); + if (type < SSH_MSG_MIN || type > SSH_MSG_MAX) + packet_disconnect("Invalid ssh1 packet type: %d", type); return type; } @@ -908,11 +1163,14 @@ packet_read_poll2(u_int32_t *seqnr_p) static u_int packet_length = 0; u_int padlen, need; u_char *macbuf, *cp, type; - int maclen, block_size; + u_int maclen, block_size; Enc *enc = NULL; Mac *mac = NULL; Comp *comp = NULL; + if (packet_discard) + return SSH_MSG_NONE; + if (newkeys[MODE_IN] != NULL) { enc = &newkeys[MODE_IN]->enc; mac = &newkeys[MODE_IN]->mac; @@ -933,10 +1191,15 @@ packet_read_poll2(u_int32_t *seqnr_p) cipher_crypt(&receive_context, cp, buffer_ptr(&input), block_size); cp = buffer_ptr(&incoming_packet); - packet_length = GET_32BIT(cp); - if (packet_length < 1 + 4 || packet_length > 256 * 1024) { + packet_length = get_u32(cp); + if (packet_length < 1 + 4 || packet_length > PACKET_MAX_SIZE) { +#ifdef PACKET_DEBUG buffer_dump(&incoming_packet); - packet_disconnect("Bad packet length %u.", packet_length); +#endif + logit("Bad packet length %u.", packet_length); + packet_start_discard(enc, mac, packet_length, + PACKET_MAX_SIZE); + return SSH_MSG_NONE; } DBG(debug("input: packet len %u", packet_length+4)); buffer_consume(&input, block_size); @@ -945,9 +1208,13 @@ packet_read_poll2(u_int32_t *seqnr_p) need = 4 + packet_length - block_size; DBG(debug("partial packet %d, need %d, maclen %d", block_size, need, maclen)); - if (need % block_size != 0) - fatal("padding error: need %d block %d mod %d", + if (need % block_size != 0) { + logit("padding error: need %d block %d mod %d", need, block_size, need % block_size); + packet_start_discard(enc, mac, packet_length, + PACKET_MAX_SIZE - block_size); + return SSH_MSG_NONE; + } /* * check if the entire packet has been received and * decrypt into incoming_packet @@ -966,18 +1233,31 @@ packet_read_poll2(u_int32_t *seqnr_p) * increment sequence number for incoming packet */ if (mac && mac->enabled) { - macbuf = mac_compute(mac, read_seqnr, + macbuf = mac_compute(mac, p_read.seqnr, buffer_ptr(&incoming_packet), buffer_len(&incoming_packet)); - if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) - packet_disconnect("Corrupted MAC on input."); - DBG(debug("MAC #%d ok", read_seqnr)); + if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) { + logit("Corrupted MAC on input."); + if (need > PACKET_MAX_SIZE) + fatal("internal error need %d", need); + packet_start_discard(enc, mac, packet_length, + PACKET_MAX_SIZE - need); + return SSH_MSG_NONE; + } + + DBG(debug("MAC #%d ok", p_read.seqnr)); buffer_consume(&input, mac->mac_len); } + /* XXX now it's safe to use fatal/packet_disconnect */ if (seqnr_p != NULL) - *seqnr_p = read_seqnr; - if (++read_seqnr == 0) - log("incoming seqnr wraps around"); + *seqnr_p = p_read.seqnr; + if (++p_read.seqnr == 0) + logit("incoming seqnr wraps around"); + if (++p_read.packets == 0) + if (!(datafellows & SSH_BUG_NOREKEY)) + fatal("XXX too many packets with same key"); + p_read.blocks += (packet_length + 4) / block_size; + p_read.bytes += packet_length + 4; /* get padlen */ cp = buffer_ptr(&incoming_packet); @@ -1005,8 +1285,12 @@ packet_read_poll2(u_int32_t *seqnr_p) * return length of payload (without type field) */ type = buffer_get_char(&incoming_packet); + if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN) + packet_disconnect("Invalid ssh2 packet type: %d", type); if (type == SSH2_MSG_NEWKEYS) set_newkeys(MODE_IN); + else if (type == SSH2_MSG_USERAUTH_SUCCESS && !server_side) + packet_enable_delayed_compress(); #ifdef PACKET_DEBUG fprintf(stderr, "read/plain[%d]:\r\n", type); buffer_dump(&incoming_packet); @@ -1026,10 +1310,13 @@ packet_read_poll_seqnr(u_int32_t *seqnr_p) for (;;) { if (compat20) { type = packet_read_poll2(seqnr_p); - if (type) + if (type) { + keep_alive_timeouts = 0; DBG(debug("received packet type %d", type)); + } switch (type) { case SSH2_MSG_IGNORE: + debug3("Received SSH2_MSG_IGNORE"); break; case SSH2_MSG_DEBUG: packet_get_char(); @@ -1042,10 +1329,10 @@ packet_read_poll_seqnr(u_int32_t *seqnr_p) case SSH2_MSG_DISCONNECT: reason = packet_get_int(); msg = packet_get_string(NULL); - log("Received disconnect from %s: %u: %.400s", + 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(); @@ -1054,7 +1341,6 @@ packet_read_poll_seqnr(u_int32_t *seqnr_p) break; default: return type; - break; } } else { type = packet_read_poll1(); @@ -1068,16 +1354,14 @@ packet_read_poll_seqnr(u_int32_t *seqnr_p) break; case SSH_MSG_DISCONNECT: msg = packet_get_string(NULL); - log("Received disconnect from %s: %.400s", + logit("Received disconnect from %s: %.400s", get_remote_ipaddr(), msg); - fatal_cleanup(); - xfree(msg); + cleanup_exit(255); break; default: if (type) DBG(debug("received packet type %d", type)); return type; - break; } } } @@ -1097,6 +1381,13 @@ packet_read_poll(void) void packet_process_incoming(const char *buf, u_int len) { + if (packet_discard) { + keep_alive_timeouts = 0; /* ?? */ + if (len >= packet_discard) + packet_stop_discard(); + packet_discard -= len; + return; + } buffer_append(&input, buf, len); } @@ -1137,9 +1428,9 @@ packet_get_bignum2(BIGNUM * value) } void * -packet_get_raw(int *length_ptr) +packet_get_raw(u_int *length_ptr) { - int bytes = buffer_len(&incoming_packet); + u_int bytes = buffer_len(&incoming_packet); if (length_ptr != NULL) *length_ptr = bytes; @@ -1165,11 +1456,10 @@ packet_get_string(u_int *length_ptr) return buffer_get_string(&incoming_packet, length_ptr); } -/* 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(&incoming_packet, length_ptr); } /* @@ -1234,7 +1524,7 @@ packet_disconnect(const char *fmt,...) va_end(args); /* Display the error locally */ - log("Disconnecting: %.100s", buf); + logit("Disconnecting: %.100s", buf); /* Send the disconnect message to the other side, and wait for it to get sent. */ if (compat20) { @@ -1254,52 +1544,86 @@ packet_disconnect(const char *fmt,...) /* Close the connection. */ packet_close(); - - fatal_cleanup(); + cleanup_exit(255); } /* Checks if there is any buffered output, and tries to write some of the output. */ -void +int packet_write_poll(void) { - int len = buffer_len(&output); + int len = 0; + len = buffer_len(&output); if (len > 0) { len = write(connection_out, buffer_ptr(&output), len); - if (len <= 0) { - if (errno == EAGAIN) - return; - else - fatal("Write failed: %.100s", strerror(errno)); + if (len == -1) { + if (errno == EINTR || errno == EAGAIN || + errno == EWOULDBLOCK) + return (0); + fatal("Write failed: %.100s", strerror(errno)); } + if (len == 0) + fatal("Write connection closed"); buffer_consume(&output, len); } + return(len); } + /* * Calls packet_write_poll repeatedly until all pending output data has been * written. */ -void +int packet_write_wait(void) { fd_set *setp; + int ret, ms_remain; + struct timeval start, timeout, *timeoutp = NULL; + u_int bytes_sent = 0; - setp = (fd_set *)xmalloc(howmany(connection_out + 1, NFDBITS) * + setp = (fd_set *)xcalloc(howmany(connection_out + 1, NFDBITS), sizeof(fd_mask)); - packet_write_poll(); + bytes_sent += packet_write_poll(); while (packet_have_data_to_write()) { memset(setp, 0, howmany(connection_out + 1, NFDBITS) * sizeof(fd_mask)); FD_SET(connection_out, setp); - while (select(connection_out + 1, NULL, setp, NULL, NULL) == -1 && - (errno == EAGAIN || errno == EINTR)) - ; - packet_write_poll(); + + if (packet_timeout_ms > 0) { + ms_remain = packet_timeout_ms; + timeoutp = &timeout; + } + for (;;) { + if (packet_timeout_ms != -1) { + ms_to_timeval(&timeout, ms_remain); + gettimeofday(&start, NULL); + } + if ((ret = select(connection_out + 1, NULL, setp, + NULL, timeoutp)) >= 0) + break; + if (errno != EAGAIN && errno != EINTR && + errno != EWOULDBLOCK) + break; + if (packet_timeout_ms == -1) + continue; + ms_subtract_diff(&start, &ms_remain); + if (ms_remain <= 0) { + ret = 0; + break; + } + } + if (ret == 0) { + logit("Connection to %.200s timed out while " + "waiting to write", get_remote_ipaddr()); + cleanup_exit(255); + } + bytes_sent += packet_write_poll(); } xfree(setp); + return (bytes_sent); } /* Returns true if there is buffered data to write to the connection. */ @@ -1321,9 +1645,11 @@ packet_not_very_much_data_to_write(void) return buffer_len(&output) < 128 * 1024; } + static void packet_set_tos(int interactive) { +#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) int tos = interactive ? IPTOS_LOWDELAY : IPTOS_THROUGHPUT; if (!packet_connection_is_on_socket() || @@ -1333,6 +1659,7 @@ packet_set_tos(int interactive) 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. */ @@ -1351,12 +1678,9 @@ packet_set_interactive(int interactive) /* Only set socket options if using a socket. */ if (!packet_connection_is_on_socket()) - if (interactive) - set_nodelay(connection_in); -#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) + return; + set_nodelay(connection_in); packet_set_tos(interactive); -#endif - } /* Returns true if the current connection is interactive. */ @@ -1368,17 +1692,17 @@ packet_is_interactive(void) } int -packet_set_maxsize(int s) +packet_set_maxsize(u_int s) { static int called = 0; if (called) { - log("packet_set_maxsize: called twice: old %d new %d", + logit("packet_set_maxsize: called twice: old %d new %d", max_packet_size, s); return -1; } if (s < 4 * 1024 || s > 1024 * 1024) { - log("packet_set_maxsize: bad size %d", s); + logit("packet_set_maxsize: bad size %d", s); return -1; } called = 1; @@ -1408,15 +1732,64 @@ 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++) { if (i % 4 == 0) - rand = arc4random(); - packet_put_char(rand & 0xff); - rand >>= 8; + rnd = arc4random(); + packet_put_char((u_char)rnd & 0xff); + rnd >>= 8; + } +} + +int rekey_requested = 0; +void +packet_request_rekeying(void) +{ + rekey_requested = 1; +} + +#define MAX_PACKETS (1U<<31) +int +packet_need_rekeying(void) +{ + if (datafellows & SSH_BUG_NOREKEY) + return 0; + if (rekey_requested == 1) + { + rekey_requested = 0; + return 1; } + return + (p_send.packets > MAX_PACKETS) || + (p_read.packets > MAX_PACKETS) || + (max_blocks_out && (p_send.blocks > max_blocks_out)) || + (max_blocks_in && (p_read.blocks > max_blocks_in)); +} + +void +packet_set_rekey_limit(u_int32_t bytes) +{ + rekey_limit = bytes; +} + +void +packet_set_server(void) +{ + server_side = 1; +} + +void +packet_set_authenticated(void) +{ + after_authentication = 1; +} + +int +packet_authentication_state(void) +{ + return(after_authentication); }