1 /* $NetBSD: print-ah.c,v 1.4 1996/05/20 00:41:16 fvdl Exp $ */
4 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that: (1) source code distributions
9 * retain the above copyright notice and this paragraph in its entirety, (2)
10 * distributions including binary code include the above copyright notice and
11 * this paragraph in its entirety in the documentation or other materials
12 * provided with the distribution, and (3) all advertising materials mentioning
13 * features or use of this software display the following acknowledgement:
14 * ``This product includes software developed by the University of California,
15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
16 * the University nor the names of its contributors may be used to endorse
17 * or promote products derived from this software without specific prior
19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
25 static const char rcsid[] _U_ =
26 "@(#) $Header: /tcpdump/master/tcpdump/print-esp.c,v 1.44.2.4 2003/11/19 05:36:40 guy Exp $ (LBL)";
35 #include <tcpdump-stdinc.h>
40 #ifdef HAVE_OPENSSL_EVP_H
41 #include <openssl/evp.h>
53 #if defined(__MINGW32__) || defined(__WATCOMC__)
54 extern char *strsep(char **stringp, const char *delim); /* Missing/strsep.c */
57 #include "interface.h"
58 #include "addrtoname.h"
61 #ifndef HAVE_SOCKADDR_STORAGE
63 struct sockaddr_storage {
65 struct sockaddr_in sin;
66 struct sockaddr_in6 sin6;
70 #define sockaddr_storage sockaddr
72 #endif /* HAVE_SOCKADDR_STORAGE */
77 struct sockaddr_storage daddr;
79 const EVP_CIPHER *evp;
82 char secret[256]; /* is that big enough for all secrets? */
86 static struct sa_list *sa_list_head = NULL;
87 static struct sa_list *sa_default = NULL;
89 static void esp_print_addsa(struct sa_list *sa, int sa_def)
95 nsa = (struct sa_list *)malloc(sizeof(struct sa_list));
97 error("ran out of memory to allocate sa structure");
104 nsa->next = sa_list_head;
109 static int hexdigit(char hex)
111 if (hex >= '0' && hex <= '9')
113 else if (hex >= 'A' && hex <= 'F')
114 return (hex - 'A' + 10);
115 else if (hex >= 'a' && hex <= 'f')
116 return (hex - 'a' + 10);
118 printf("invalid hex digit %c in espsecret\n", hex);
123 static int hex2byte(char *hexstring)
127 byte = (hexdigit(hexstring[0]) << 4) + hexdigit(hexstring[1]);
132 * decode the form: SPINUM@IP <tab> ALGONAME:0xsecret
134 * special form: file /name
135 * causes us to go read from this file instead.
138 static void esp_print_decode_onesecret(char *line)
146 spikey = strsep(&line, " \t");
148 memset(&sa1, 0, sizeof(struct sa_list));
150 /* if there is only one token, then it is an algo:key token */
154 /* memset(&sa1.daddr, 0, sizeof(sa1.daddr)); */
160 if (spikey && strcasecmp(spikey, "file") == 0) {
161 /* open file and read it */
166 secretfile = fopen(line, FOPEN_READ_TXT);
167 if (secretfile == NULL) {
172 while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {
173 /* remove newline from the line */
174 nl = strchr(fileline, '\n');
177 if (fileline[0] == '#') continue;
178 if (fileline[0] == '\0') continue;
180 esp_print_decode_onesecret(fileline);
190 struct sockaddr_in *sin;
192 struct sockaddr_in6 *sin6;
195 spistr = strsep(&spikey, "@");
197 spino = strtoul(spistr, &foo, 0);
198 if (spistr == foo || !spikey) {
199 printf("print_esp: failed to decode spi# %s\n", foo);
205 sin = (struct sockaddr_in *)&sa1.daddr;
207 sin6 = (struct sockaddr_in6 *)&sa1.daddr;
208 if (inet_pton(AF_INET6, spikey, &sin6->sin6_addr) == 1) {
209 #ifdef HAVE_SOCKADDR_SA_LEN
210 sin6->sin6_len = sizeof(struct sockaddr_in6);
212 sin6->sin6_family = AF_INET6;
215 if (inet_pton(AF_INET, spikey, &sin->sin_addr) == 1) {
216 #ifdef HAVE_SOCKADDR_SA_LEN
217 sin->sin_len = sizeof(struct sockaddr_in);
219 sin->sin_family = AF_INET;
221 printf("print_esp: can not decode IP# %s\n", spikey);
228 char espsecret_key[256];
231 const EVP_CIPHER *evp;
235 /* skip any blank spaces */
236 while (isspace((unsigned char)*decode))
239 colon = strchr(decode, ':');
241 printf("failed to decode espsecret: %s\n", decode);
246 len = colon - decode;
247 if (strlen(decode) > strlen("-hmac96") &&
248 !strcmp(decode + strlen(decode) - strlen("-hmac96"),
250 p = strstr(decode, "-hmac96");
254 if (strlen(decode) > strlen("-cbc") &&
255 !strcmp(decode + strlen(decode) - strlen("-cbc"), "-cbc")) {
256 p = strstr(decode, "-cbc");
259 evp = EVP_get_cipherbyname(decode);
261 printf("failed to find cipher algo %s\n", decode);
269 sa1.authlen = authlen;
273 if (colon[0] == '0' && colon[1] == 'x') {
274 /* decode some hex! */
276 len = strlen(colon) / 2;
279 printf("secret is too big: %d\n", len);
284 while (colon[0] != '\0' && colon[1]!='\0') {
285 espsecret_key[i] = hex2byte(colon);
290 memcpy(sa1.secret, espsecret_key, i);
295 if (i < sizeof(sa1.secret)) {
296 memcpy(sa1.secret, colon, i);
299 memcpy(sa1.secret, colon, sizeof(sa1.secret));
300 sa1.secretlen = sizeof(sa1.secret);
305 esp_print_addsa(&sa1, sa_def);
308 static void esp_print_decodesecret(void)
315 while (espsecret && espsecret[0] != '\0') {
316 /* pick out the first line or first thing until a comma */
317 if ((line = strsep(&espsecret, "\n,")) == NULL) {
322 esp_print_decode_onesecret(line);
326 static void esp_init(void)
329 OpenSSL_add_all_algorithms();
330 EVP_add_cipher_alias(SN_des_ede3_cbc, "3des");
335 esp_print(const u_char *bp, const u_char *bp2
336 #ifndef HAVE_LIBCRYPTO
341 #ifndef HAVE_LIBCRYPTO
346 #ifndef HAVE_LIBCRYPTO
351 register const struct newesp *esp;
352 register const u_char *ep;
353 #ifdef HAVE_LIBCRYPTO
355 struct sa_list *sa = NULL;
356 int espsecret_keylen;
358 struct ip6_hdr *ip6 = NULL;
368 static int initialized = 0;
371 esp = (struct newesp *)bp;
373 #ifdef HAVE_LIBCRYPTO
384 /* keep secret out of a register */
385 p = (u_char *)&secret;
388 /* 'ep' points to the end of available data. */
391 if ((u_char *)(esp + 1) >= ep) {
392 fputs("[|ESP]", stdout);
395 printf("ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi));
396 printf(",seq=0x%x", EXTRACT_32BITS(&esp->esp_seq));
399 #ifndef HAVE_LIBCRYPTO
402 /* initiailize SAs */
403 if (sa_list_head == NULL) {
407 esp_print_decodesecret();
410 if (sa_list_head == NULL)
413 ip = (struct ip *)bp2;
417 ip6 = (struct ip6_hdr *)bp2;
418 /* we do not attempt to decrypt jumbograms */
419 if (!EXTRACT_16BITS(&ip6->ip6_plen))
421 /* if we can't get nexthdr, we do not need to decrypt it */
422 len = sizeof(struct ip6_hdr) + EXTRACT_16BITS(&ip6->ip6_plen);
424 /* see if we can find the SA, and if so, decode it */
425 for (sa = sa_list_head; sa != NULL; sa = sa->next) {
426 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&sa->daddr;
427 if (sa->spi == ntohl(esp->esp_spi) &&
428 sin6->sin6_family == AF_INET6 &&
429 memcmp(&sin6->sin6_addr, &ip6->ip6_dst,
430 sizeof(struct in6_addr)) == 0) {
437 /* nexthdr & padding are in the last fragment */
438 if (EXTRACT_16BITS(&ip->ip_off) & IP_MF)
440 len = EXTRACT_16BITS(&ip->ip_len);
442 /* see if we can find the SA, and if so, decode it */
443 for (sa = sa_list_head; sa != NULL; sa = sa->next) {
444 struct sockaddr_in *sin = (struct sockaddr_in *)&sa->daddr;
445 if (sa->spi == ntohl(esp->esp_spi) &&
446 sin->sin_family == AF_INET &&
447 sin->sin_addr.s_addr == ip->ip_dst.s_addr) {
456 /* if we didn't find the specific one, then look for
457 * an unspecified one.
462 /* if not found fail */
466 /* if we can't get nexthdr, we do not need to decrypt it */
469 if (ep - bp2 > len) {
470 /* FCS included at end of frame (NetBSD 1.6 or later) */
474 ivoff = (u_char *)(esp + 1) + 0;
477 espsecret_keylen = sa->secretlen;
480 memset(&ctx, 0, sizeof(ctx));
481 if (EVP_CipherInit(&ctx, sa->evp, secret, NULL, 0) < 0)
482 printf("espkey init failed");
484 blocksz = EVP_CIPHER_CTX_block_size(&ctx);
487 EVP_CipherInit(&ctx, NULL, NULL, p, 0);
488 EVP_Cipher(&ctx, p + ivlen, p + ivlen, ep - (p + ivlen));
489 advance = ivoff - (u_char *)esp + ivlen;
491 advance = sizeof(struct newesp);
493 ep = ep - sa->authlen;
494 /* sanity check for pad length */
495 if (ep - bp < *(ep - 2))
499 *padlen = *(ep - 2) + 2;