X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/799ae497fc1f308e76517858d866bdd27b56cdd8..db5d66a5072fed3b0983cd21ee48f5c290939ca6:/openssh/packet.c?ds=sidebyside diff --git a/openssh/packet.c b/openssh/packet.c index 7d8fab1..7b77e29 100644 --- a/openssh/packet.c +++ b/openssh/packet.c @@ -1,4 +1,4 @@ -/* $OpenBSD: packet.c,v 1.145 2006/09/19 21:14:08 markus Exp $ */ +/* $OpenBSD: packet.c,v 1.160 2009/02/13 11:50:21 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -84,6 +84,8 @@ #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 @@ -136,12 +138,18 @@ 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 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; @@ -154,6 +162,10 @@ 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; @@ -186,7 +198,51 @@ packet_set_connection(int fd_in, int fd_out) buffer_init(&outgoing_packet); buffer_init(&incoming_packet); TAILQ_INIT(&outgoing); + p_send.packets = p_read.packets = 0; + } +} + +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. */ @@ -293,18 +349,25 @@ packet_get_ssh1_cipher(void) } void -packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks, u_int32_t *packets) +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) ? &p_read : &p_send; - *seqnr = state->seqnr; - *blocks = state->blocks; - *packets = state->packets; + 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) +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; @@ -312,6 +375,7 @@ packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets) state->seqnr = seqnr; state->blocks = blocks; state->packets = packets; + state->bytes = bytes; } /* returns 1 if connection is via ipv4 */ @@ -590,7 +654,8 @@ 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); /* @@ -629,7 +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); @@ -644,14 +709,15 @@ 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, 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(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) { @@ -709,7 +775,7 @@ packet_enable_delayed_compress(void) /* * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) */ -static void +static int packet_send2_wrapped(void) { u_char type, *cp, *macbuf = NULL; @@ -815,17 +881,20 @@ packet_send2_wrapped(void) 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); } -static void +static int packet_send2(void) { + static int packet_length = 0; static int rekeying = 0; struct packet *p; u_char type, *cp; @@ -843,7 +912,7 @@ packet_send2(void) memcpy(&p->payload, &outgoing_packet, sizeof(Buffer)); buffer_init(&outgoing_packet); TAILQ_INSERT_TAIL(&outgoing, p, next); - return; + return(sizeof(Buffer)); } } @@ -851,7 +920,7 @@ packet_send2(void) if (type == SSH2_MSG_KEXINIT) rekeying = 1; - packet_send2_wrapped(); + packet_length = packet_send2_wrapped(); /* after a NEWKEYS message we can send the complete queue */ if (type == SSH2_MSG_NEWKEYS) { @@ -864,19 +933,22 @@ packet_send2(void) sizeof(Buffer)); TAILQ_REMOVE(&outgoing, p, next); xfree(p); - packet_send2_wrapped(); + packet_length += packet_send2_wrapped(); } } + return(packet_length); } -void +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); } /* @@ -888,9 +960,11 @@ 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 *)xcalloc(howmany(connection_in+1, NFDBITS), @@ -922,11 +996,35 @@ 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) { @@ -1051,6 +1149,8 @@ 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); @@ -1068,6 +1168,9 @@ packet_read_poll2(u_int32_t *seqnr_p) 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; @@ -1089,11 +1192,14 @@ packet_read_poll2(u_int32_t *seqnr_p) block_size); cp = buffer_ptr(&incoming_packet); packet_length = get_u32(cp); - if (packet_length < 1 + 4 || packet_length > 256 * 1024) { + if (packet_length < 1 + 4 || packet_length > PACKET_MAX_SIZE) { #ifdef PACKET_DEBUG buffer_dump(&incoming_packet); #endif - packet_disconnect("Bad packet length %u.", packet_length); + 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); @@ -1102,9 +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 @@ -1126,11 +1236,19 @@ packet_read_poll2(u_int32_t *seqnr_p) 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."); + 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 = p_read.seqnr; if (++p_read.seqnr == 0) @@ -1139,6 +1257,7 @@ packet_read_poll2(u_int32_t *seqnr_p) 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); @@ -1191,10 +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(); @@ -1235,7 +1357,6 @@ packet_read_poll_seqnr(u_int32_t *seqnr_p) logit("Received disconnect from %s: %.400s", get_remote_ipaddr(), msg); cleanup_exit(255); - xfree(msg); break; default: if (type) @@ -1260,6 +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); } @@ -1328,6 +1456,12 @@ packet_get_string(u_int *length_ptr) return buffer_get_string(&incoming_packet, length_ptr); } +void * +packet_get_string_ptr(u_int *length_ptr) +{ + return buffer_get_string_ptr(&incoming_packet, length_ptr); +} + /* * Sends a diagnostic message from the server to the client. This message * can be sent at any time (but not while constructing another message). The @@ -1415,46 +1549,81 @@ packet_disconnect(const char *fmt,...) /* 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 *)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. */ @@ -1576,12 +1745,24 @@ packet_send_ignore(int nbytes) } } +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) || @@ -1606,3 +1787,9 @@ packet_set_authenticated(void) { after_authentication = 1; } + +int +packet_authentication_state(void) +{ + return(after_authentication); +}