X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/22616013c4eef383b19b8ad4f95780a316d0a51b..033af9549c8e22d8cfd355c4fd869ca63936ab66:/openssh/packet.c diff --git a/openssh/packet.c b/openssh/packet.c index 8abd43e..7b77e29 100644 --- a/openssh/packet.c +++ b/openssh/packet.c @@ -1,4 +1,4 @@ -/* $OpenBSD: packet.c,v 1.157 2008/07/10 18:08:11 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 @@ -160,6 +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; @@ -209,6 +215,36 @@ packet_set_timeout(int timeout, int count) 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. */ int @@ -739,7 +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; @@ -852,11 +888,13 @@ packet_send2_wrapped(void) 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; @@ -874,7 +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)); } } @@ -882,7 +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) { @@ -895,19 +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); } /* @@ -1127,6 +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; @@ -1148,11 +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); @@ -1161,9 +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 @@ -1185,11 +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) @@ -1322,6 +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); } @@ -1483,23 +1549,25 @@ 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 == -1) { if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK) - return; + return (0); fatal("Write failed: %.100s", strerror(errno)); } if (len == 0) fatal("Write connection closed"); buffer_consume(&output, len); } + return(len); } @@ -1508,16 +1576,17 @@ packet_write_poll(void) * 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)); @@ -1551,9 +1620,10 @@ packet_write_wait(void) "waiting to write", get_remote_ipaddr()); cleanup_exit(255); } - packet_write_poll(); + bytes_sent += packet_write_poll(); } xfree(setp); + return (bytes_sent); } /* Returns true if there is buffered data to write to the connection. */ @@ -1675,12 +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) || @@ -1705,3 +1787,9 @@ packet_set_authenticated(void) { after_authentication = 1; } + +int +packet_authentication_state(void) +{ + return(after_authentication); +}