diff options
Diffstat (limited to 'usr.bin')
| -rw-r--r-- | usr.bin/ssh/packet.c | 205 | ||||
| -rw-r--r-- | usr.bin/ssh/packet.h | 7 | ||||
| -rw-r--r-- | usr.bin/ssh/sshconnect.c | 4 | ||||
| -rw-r--r-- | usr.bin/ssh/sshd.c | 4 |
4 files changed, 62 insertions, 158 deletions
diff --git a/usr.bin/ssh/packet.c b/usr.bin/ssh/packet.c index 00109eaf63d..2ceecfb4a81 100644 --- a/usr.bin/ssh/packet.c +++ b/usr.bin/ssh/packet.c @@ -37,7 +37,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: packet.c,v 1.61 2001/04/05 10:42:51 markus Exp $"); +RCSID("$OpenBSD: packet.c,v 1.62 2001/05/28 23:58:35 markus Exp $"); #include "xmalloc.h" #include "buffer.h" @@ -75,12 +75,6 @@ RCSID("$OpenBSD: packet.c,v 1.61 2001/04/05 10:42:51 markus Exp $"); static int connection_in = -1; static int connection_out = -1; -/* - * Cipher type. This value is only used to determine whether to pad the - * packets with zeroes or random data. - */ -static int cipher_type = SSH_CIPHER_NONE; - /* Protocol flags for the remote side. */ static u_int remote_protocol_flags = 0; @@ -118,20 +112,9 @@ static int initialized = 0; /* Set to true if the connection is interactive. */ static int interactive_mode = 0; -/* True if SSH2 packet format is used */ -int use_ssh2_packet_format = 0; - /* Session key information for Encryption and MAC */ Newkeys *newkeys[MODE_MAX]; -void -packet_set_ssh2_format(void) -{ - DBG(debug("use_ssh2_packet_format")); - use_ssh2_packet_format = 1; - newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL; -} - /* * Sets the descriptors used for communication. Disables encryption until * packet_set_encryption_key is called. @@ -144,9 +127,9 @@ 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_type = SSH_CIPHER_NONE; 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); @@ -290,7 +273,7 @@ packet_init_compression() void packet_start_compression(int level) { - if (packet_compression && !use_ssh2_packet_format) + if (packet_compression && !compat20) fatal("Compression already enabled."); packet_compression = 1; packet_init_compression(); @@ -299,43 +282,10 @@ packet_start_compression(int level) } /* - * Encrypts the given number of bytes, copying from src to dest. bytes is - * known to be a multiple of 8. - */ - -void -packet_encrypt(CipherContext * cc, void *dest, void *src, - u_int bytes) -{ - cipher_encrypt(cc, dest, src, bytes); -} - -/* - * Decrypts the given number of bytes, copying from src to dest. bytes is - * known to be a multiple of 8. - */ - -void -packet_decrypt(CipherContext *context, void *dest, void *src, u_int bytes) -{ - /* - * Cryptographic attack detector for ssh - Modifications for packet.c - * (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com) - */ - if (!compat20 && - context->cipher->number != SSH_CIPHER_NONE && - detect_attack(src, bytes, NULL) == DEATTACK_DETECTED) - packet_disconnect("crc32 compensation attack: network attack detected"); - - cipher_decrypt(context, dest, src, bytes); -} - -/* * Causes any further packets to be encrypted using the given key. The same * 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) @@ -349,61 +299,33 @@ packet_set_encryption_key(const u_char *key, u_int keylen, cipher_init(&send_context, cipher, key, keylen, NULL, 0); } -/* Starts constructing a packet to send. */ - +/* Start constructing a packet to send. */ void -packet_start1(int type) +packet_start(u_char type) { - char buf[9]; - - buffer_clear(&outgoing_packet); - memset(buf, 0, 8); - buf[8] = type; - buffer_append(&outgoing_packet, buf, 9); -} - -void -packet_start2(int type) -{ - char buf[4+1+1]; - - buffer_clear(&outgoing_packet); - memset(buf, 0, sizeof buf); - /* buf[0..3] = payload_len; */ - /* buf[4] = pad_len; */ - buf[5] = type & 0xff; - buffer_append(&outgoing_packet, buf, sizeof buf); -} + u_char buf[9]; + int len; -void -packet_start(int type) -{ DBG(debug("packet_start[%d]", type)); - if (use_ssh2_packet_format) - packet_start2(type); - else - packet_start1(type); + len = compat20 ? 6 : 9; + memset(buf, 0, len - 1); + buf[len - 1] = type; + buffer_clear(&outgoing_packet); + buffer_append(&outgoing_packet, buf, len); } -/* Appends a character to the packet data. */ - +/* Append payload. */ void packet_put_char(int value) { char ch = value; buffer_append(&outgoing_packet, &ch, 1); } - -/* Appends an integer to the packet data. */ - void packet_put_int(u_int value) { buffer_put_int(&outgoing_packet, value); } - -/* Appends a string to packet data. */ - void packet_put_string(const char *buf, u_int len) { @@ -414,16 +336,11 @@ packet_put_cstring(const char *str) { buffer_put_string(&outgoing_packet, str, strlen(str)); } - void packet_put_raw(const char *buf, u_int len) { buffer_append(&outgoing_packet, buf, len); } - - -/* Appends an arbitrary precision integer to packet data. */ - void packet_put_bignum(BIGNUM * value) { @@ -468,7 +385,7 @@ packet_send1(void) /* Insert padding. Initialized to zero in packet_start1() */ padding = 8 - len % 8; - if (cipher_type != SSH_CIPHER_NONE) { + if (send_context.cipher->number != SSH_CIPHER_NONE) { cp = buffer_ptr(&outgoing_packet); for (i = 0; i < padding; i++) { if (i % 4 == 0) @@ -494,7 +411,7 @@ packet_send1(void) PUT_32BIT(buf, len); buffer_append(&output, buf, 4); buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); - packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), + cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), buffer_len(&outgoing_packet)); #ifdef PACKET_DEBUG @@ -568,12 +485,11 @@ void packet_send2(void) { static u_int32_t seqnr = 0; - u_char *macbuf = NULL; + u_char type, *ucp, *macbuf = NULL; char *cp; u_int packet_length = 0; u_int i, padlen, len; u_int32_t rand = 0; - int type; Enc *enc = NULL; Mac *mac = NULL; Comp *comp = NULL; @@ -586,8 +502,8 @@ packet_send2(void) } block_size = enc ? enc->cipher->block_size : 8; - cp = buffer_ptr(&outgoing_packet); - type = cp[5] & 0xff; + ucp = (u_char *) buffer_ptr(&outgoing_packet); + type = ucp[5]; #ifdef PACKET_DEBUG fprintf(stderr, "plain: "); @@ -633,9 +549,9 @@ 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); - cp[4] = padlen & 0xff; + ucp = (u_char *)buffer_ptr(&outgoing_packet); + PUT_32BIT(ucp, packet_length); + ucp[4] = padlen; DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); /* compute MAC over seqnr and packet(length fields, payload, padding) */ @@ -647,7 +563,7 @@ packet_send2(void) } /* encrypt packet and append to output buffer. */ buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); - packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), + cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), buffer_len(&outgoing_packet)); /* append unencrypted MAC */ if (mac && mac->enabled) @@ -668,7 +584,7 @@ packet_send2(void) void packet_send() { - if (use_ssh2_packet_format) + if (compat20) packet_send2(); else packet_send1(); @@ -699,7 +615,7 @@ packet_read(int *payload_len_ptr) for (;;) { /* Try to read a packet from the buffer. */ type = packet_read_poll(payload_len_ptr); - if (!use_ssh2_packet_format && ( + if (!compat20 && ( type == SSH_SMSG_SUCCESS || type == SSH_SMSG_FAILURE || type == SSH_CMSG_EOF @@ -772,8 +688,8 @@ int packet_read_poll1(int *payload_len_ptr) { u_int len, padded_len; - u_char *ucp; - char buf[8], *cp; + u_char *ucp, type; + char *cp; u_int checksum, stored_checksum; /* Check if input size is less than minimum packet size. */ @@ -795,10 +711,20 @@ packet_read_poll1(int *payload_len_ptr) /* Consume packet length. */ buffer_consume(&input, 4); - /* Copy data to incoming_packet. */ + /* + * 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"); + + /* Decrypt data to incoming_packet. */ buffer_clear(&incoming_packet); buffer_append_space(&incoming_packet, &cp, padded_len); - packet_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len); + cipher_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len); + buffer_consume(&input, padded_len); #ifdef PACKET_DEBUG @@ -814,7 +740,6 @@ packet_read_poll1(int *payload_len_ptr) buffer_consume(&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)); @@ -825,7 +750,6 @@ packet_read_poll1(int *payload_len_ptr) packet_disconnect("Corrupted check bytes on input."); buffer_consume_end(&incoming_packet, 4); - /* If using packet compression, decompress the packet. */ if (packet_compression) { buffer_clear(&compression_buffer); buffer_uncompress(&incoming_packet, &compression_buffer); @@ -833,14 +757,9 @@ packet_read_poll1(int *payload_len_ptr) buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), buffer_len(&compression_buffer)); } - /* Get packet type. */ - buffer_get(&incoming_packet, &buf[0], 1); - - /* Return length of payload (without type field). */ + type = buffer_get_char(&incoming_packet); *payload_len_ptr = buffer_len(&incoming_packet); - - /* Return type. */ - return (u_char) buf[0]; + return type; } int @@ -849,10 +768,8 @@ packet_read_poll2(int *payload_len_ptr) static u_int32_t seqnr = 0; static u_int packet_length = 0; u_int padlen, need; - u_char buf[8], *macbuf; - u_char *ucp; + u_char *macbuf, *ucp, type; char *cp; - int type; int maclen, block_size; Enc *enc = NULL; Mac *mac = NULL; @@ -875,7 +792,7 @@ packet_read_poll2(int *payload_len_ptr) return SSH_MSG_NONE; buffer_clear(&incoming_packet); buffer_append_space(&incoming_packet, &cp, block_size); - packet_decrypt(&receive_context, cp, buffer_ptr(&input), + cipher_decrypt(&receive_context, cp, buffer_ptr(&input), block_size); ucp = (u_char *) buffer_ptr(&incoming_packet); packet_length = GET_32BIT(ucp); @@ -904,7 +821,7 @@ packet_read_poll2(int *payload_len_ptr) buffer_dump(&input); #endif buffer_append_space(&incoming_packet, &cp, need); - packet_decrypt(&receive_context, cp, buffer_ptr(&input), need); + cipher_decrypt(&receive_context, cp, buffer_ptr(&input), need); buffer_consume(&input, need); /* * compute MAC over seqnr and packet, @@ -924,7 +841,7 @@ packet_read_poll2(int *payload_len_ptr) /* get padlen */ cp = buffer_ptr(&incoming_packet) + 4; - padlen = *cp & 0xff; + padlen = (u_char) *cp; DBG(debug("input: padlen %d", padlen)); if (padlen < 4) packet_disconnect("Corrupted padlen %d on input.", padlen); @@ -946,37 +863,30 @@ packet_read_poll2(int *payload_len_ptr) * get packet type, implies consume. * return length of payload (without type field) */ - buffer_get(&incoming_packet, (char *)&buf[0], 1); - *payload_len_ptr = buffer_len(&incoming_packet); - - /* reset for next packet */ - packet_length = 0; - - /* extract packet type */ - type = (u_char)buf[0]; - + type = buffer_get_char(&incoming_packet); if (type == SSH2_MSG_NEWKEYS) set_newkeys(MODE_IN); - + *payload_len_ptr = buffer_len(&incoming_packet); #ifdef PACKET_DEBUG fprintf(stderr, "read/plain[%d]:\r\n", type); buffer_dump(&incoming_packet); #endif - return (u_char)type; + /* reset for next packet */ + packet_length = 0; + return type; } int packet_read_poll(int *payload_len_ptr) { + int reason; + u_char type; char *msg; - for (;;) { - int type = use_ssh2_packet_format ? - packet_read_poll2(payload_len_ptr): - packet_read_poll1(payload_len_ptr); - if(compat20) { - int reason; - if (type != 0) + for (;;) { + if (compat20) { + type = packet_read_poll2(payload_len_ptr); + if (type) DBG(debug("received packet type %d", type)); switch(type) { case SSH2_MSG_IGNORE: @@ -1002,6 +912,7 @@ packet_read_poll(int *payload_len_ptr) break; } } else { + type = packet_read_poll1(payload_len_ptr); switch(type) { case SSH_MSG_IGNORE: break; @@ -1018,7 +929,7 @@ packet_read_poll(int *payload_len_ptr) xfree(msg); break; default: - if (type != 0) + if (type) DBG(debug("received packet type %d", type)); return type; break; @@ -1339,7 +1250,7 @@ packet_inject_ignore(int sumlen) int blocksize, padlen, have, need, nb, mini, nbytes; Enc *enc = NULL; - if (use_ssh2_packet_format == 0) + if (compat20 == 0) return; have = buffer_len(&outgoing_packet); diff --git a/usr.bin/ssh/packet.h b/usr.bin/ssh/packet.h index 0f5e7104997..6430bb0be68 100644 --- a/usr.bin/ssh/packet.h +++ b/usr.bin/ssh/packet.h @@ -11,7 +11,7 @@ * called by a name other than "ssh" or "Secure Shell". */ -/* RCSID("$OpenBSD: packet.h,v 1.22 2001/04/14 16:33:20 stevesk Exp $"); */ +/* RCSID("$OpenBSD: packet.h,v 1.23 2001/05/28 23:58:35 markus Exp $"); */ #ifndef PACKET_H #define PACKET_H @@ -71,7 +71,7 @@ void packet_set_interactive(int interactive); int packet_is_interactive(void); /* Starts constructing a packet to send. */ -void packet_start(int type); +void packet_start(u_char type); /* Appends a character to the packet data. */ void packet_put_char(int ch); @@ -208,9 +208,6 @@ do { \ int packet_connection_is_on_socket(void); int packet_connection_is_ipv4(void); -/* enable SSH2 packet format */ -void packet_set_ssh2_format(void); - /* returns remaining payload bytes */ int packet_remaining(void); diff --git a/usr.bin/ssh/sshconnect.c b/usr.bin/ssh/sshconnect.c index 39a661a6602..b472f81d435 100644 --- a/usr.bin/ssh/sshconnect.c +++ b/usr.bin/ssh/sshconnect.c @@ -13,7 +13,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: sshconnect.c,v 1.105 2001/04/30 11:18:52 markus Exp $"); +RCSID("$OpenBSD: sshconnect.c,v 1.106 2001/05/28 23:58:35 markus Exp $"); #include <openssl/bn.h> @@ -426,8 +426,6 @@ ssh_exchange_identification(void) fatal("Protocol major versions differ: %d vs. %d", (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, remote_major); - if (compat20) - packet_set_ssh2_format(); /* Send our own protocol version identification. */ snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, diff --git a/usr.bin/ssh/sshd.c b/usr.bin/ssh/sshd.c index fb7e058b980..b70fbcbfad4 100644 --- a/usr.bin/ssh/sshd.c +++ b/usr.bin/ssh/sshd.c @@ -40,7 +40,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: sshd.c,v 1.197 2001/05/19 19:43:57 stevesk Exp $"); +RCSID("$OpenBSD: sshd.c,v 1.198 2001/05/28 23:58:35 markus Exp $"); #include <openssl/dh.h> #include <openssl/bn.h> @@ -426,8 +426,6 @@ sshd_exchange_identification(int sock_in, int sock_out) server_version_string, client_version_string); fatal_cleanup(); } - if (compat20) - packet_set_ssh2_format(); } |