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.
24 /* \summary: IPSEC Encapsulating Security Payload (ESP) printer */
30 #include <netdissect-stdinc.h>
35 /* Any code in this file that depends on HAVE_LIBCRYPTO depends on
36 * HAVE_OPENSSL_EVP_H too. Undefining the former when the latter isn't defined
37 * is the simplest way of handling the dependency.
40 #ifdef HAVE_OPENSSL_EVP_H
41 #include <openssl/evp.h>
47 #include "netdissect.h"
48 #include "strtoaddr.h"
51 #include "ascii_strcasecmp.h"
57 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
58 * All rights reserved.
60 * Redistribution and use in source and binary forms, with or without
61 * modification, are permitted provided that the following conditions
63 * 1. Redistributions of source code must retain the above copyright
64 * notice, this list of conditions and the following disclaimer.
65 * 2. Redistributions in binary form must reproduce the above copyright
66 * notice, this list of conditions and the following disclaimer in the
67 * documentation and/or other materials provided with the distribution.
68 * 3. Neither the name of the project nor the names of its contributors
69 * may be used to endorse or promote products derived from this software
70 * without specific prior written permission.
72 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
73 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
74 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
75 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
76 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
77 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
78 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
79 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
80 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
81 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
86 * RFC1827/2406 Encapsulated Security Payload.
90 uint32_t esp_spi; /* ESP */
91 uint32_t esp_seq; /* Sequence number */
92 /*variable size*/ /* (IV and) Payload data */
93 /*variable size*/ /* padding */
94 /*8bit*/ /* pad size */
95 /*8bit*/ /* next header */
96 /*8bit*/ /* next header */
97 /*variable size, 32bit bound*/ /* Authentication data */
100 #ifdef HAVE_LIBCRYPTO
106 struct sa_list *next;
108 union inaddr_u daddr;
109 uint32_t spi; /* if == 0, then IKEv2 */
111 u_char spii[8]; /* for IKEv2 */
113 const EVP_CIPHER *evp;
116 u_char authsecret[256];
118 u_char secret[256]; /* is that big enough for all secrets? */
122 #ifndef HAVE_EVP_CIPHER_CTX_NEW
124 * Allocate an EVP_CIPHER_CTX.
125 * Used if we have an older version of OpenSSL that doesn't provide
126 * routines to allocate and free them.
128 static EVP_CIPHER_CTX *
129 EVP_CIPHER_CTX_new(void)
133 ctx = malloc(sizeof(*ctx));
136 memset(ctx, 0, sizeof(*ctx));
141 EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
143 EVP_CIPHER_CTX_cleanup(ctx);
148 #ifdef HAVE_EVP_CIPHERINIT_EX
150 * Initialize the cipher by calling EVP_CipherInit_ex(), because
151 * calling EVP_CipherInit() will reset the cipher context, clearing
152 * the cipher, so calling it twice, with the second call having a
153 * null cipher, will clear the already-set cipher. EVP_CipherInit_ex(),
154 * however, won't reset the cipher context, so you can use it to specify
155 * the IV oin a second call after a first call to EVP_CipherInit_ex()
156 * to set the cipher and the key.
158 * XXX - is there some reason why we need to make two calls?
161 set_cipher_parameters(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
162 const unsigned char *key,
163 const unsigned char *iv, int enc)
165 return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
169 * Initialize the cipher by calling EVP_CipherInit(), because we don't
170 * have EVP_CipherInit_ex(); we rely on it not trashing the context.
173 set_cipher_parameters(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
174 const unsigned char *key,
175 const unsigned char *iv, int enc)
177 return EVP_CipherInit(ctx, cipher, key, iv, enc);
182 * this will adjust ndo_packetp and ndo_snapend to new buffer!
184 USES_APPLE_DEPRECATED_API
185 int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo,
187 u_char spii[8], u_char spir[8],
188 const u_char *buf, const u_char *end)
194 unsigned int block_size, output_buffer_size;
195 u_char *output_buffer;
197 /* initiator arg is any non-zero value */
198 if(initiator) initiator=1;
200 /* see if we can find the SA, and if so, decode it */
201 for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
203 && initiator == sa->initiator
204 && memcmp(spii, sa->spii, 8) == 0
205 && memcmp(spir, sa->spir, 8) == 0)
209 if(sa == NULL) return 0;
210 if(sa->evp == NULL) return 0;
213 * remove authenticator, and see if we still have something to
216 end = end - sa->authlen;
218 buf = buf + sa->ivlen;
221 if(end <= buf) return 0;
223 ctx = EVP_CIPHER_CTX_new();
226 if (set_cipher_parameters(ctx, sa->evp, sa->secret, NULL, 0) < 0)
227 (*ndo->ndo_warning)(ndo, "espkey init failed");
228 set_cipher_parameters(ctx, NULL, NULL, iv, 0);
230 * Allocate a buffer for the decrypted data.
231 * The output buffer must be separate from the input buffer, and
232 * its size must be a multiple of the cipher block size.
234 block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx);
235 output_buffer_size = len + (block_size - len % block_size);
236 output_buffer = (u_char *)malloc(output_buffer_size);
237 if (output_buffer == NULL) {
238 (*ndo->ndo_warning)(ndo, "can't allocate memory for decryption buffer");
239 EVP_CIPHER_CTX_free(ctx);
242 EVP_Cipher(ctx, output_buffer, buf, len);
243 EVP_CIPHER_CTX_free(ctx);
246 * XXX - of course this is wrong, because buf is a const buffer,
247 * but changing this would require a more complicated fix.
249 memcpy(__DECONST(u_char *, buf), output_buffer, len);
252 ndo->ndo_packetp = buf;
253 ndo->ndo_snapend = end;
259 static void esp_print_addsa(netdissect_options *ndo,
260 struct sa_list *sa, int sa_def)
266 nsa = (struct sa_list *)malloc(sizeof(struct sa_list));
268 (*ndo->ndo_error)(ndo, "ran out of memory to allocate sa structure");
273 ndo->ndo_sa_default = nsa;
275 nsa->next = ndo->ndo_sa_list_head;
276 ndo->ndo_sa_list_head = nsa;
280 static u_int hexdigit(netdissect_options *ndo, char hex)
282 if (hex >= '0' && hex <= '9')
284 else if (hex >= 'A' && hex <= 'F')
285 return (hex - 'A' + 10);
286 else if (hex >= 'a' && hex <= 'f')
287 return (hex - 'a' + 10);
289 (*ndo->ndo_error)(ndo, "invalid hex digit %c in espsecret\n", hex);
294 static u_int hex2byte(netdissect_options *ndo, char *hexstring)
298 byte = (hexdigit(ndo, hexstring[0]) << 4) + hexdigit(ndo, hexstring[1]);
303 * returns size of binary, 0 on failure.
306 int espprint_decode_hex(netdissect_options *ndo,
307 u_char *binbuf, unsigned int binbuf_len,
313 len = strlen(hex) / 2;
315 if (len > binbuf_len) {
316 (*ndo->ndo_warning)(ndo, "secret is too big: %d\n", len);
321 while (hex[0] != '\0' && hex[1]!='\0') {
322 binbuf[i] = hex2byte(ndo, hex);
331 * decode the form: SPINUM@IP <tab> ALGONAME:0xsecret
334 USES_APPLE_DEPRECATED_API
336 espprint_decode_encalgo(netdissect_options *ndo,
337 char *decode, struct sa_list *sa)
340 const EVP_CIPHER *evp;
344 colon = strchr(decode, ':');
346 (*ndo->ndo_warning)(ndo, "failed to decode espsecret: %s\n", decode);
351 if (strlen(decode) > strlen("-hmac96") &&
352 !strcmp(decode + strlen(decode) - strlen("-hmac96"),
354 p = strstr(decode, "-hmac96");
358 if (strlen(decode) > strlen("-cbc") &&
359 !strcmp(decode + strlen(decode) - strlen("-cbc"), "-cbc")) {
360 p = strstr(decode, "-cbc");
363 evp = EVP_get_cipherbyname(decode);
366 (*ndo->ndo_warning)(ndo, "failed to find cipher algo %s\n", decode);
374 sa->authlen = authlen;
375 sa->ivlen = EVP_CIPHER_iv_length(evp);
378 if (colon[0] == '0' && colon[1] == 'x') {
379 /* decode some hex! */
382 sa->secretlen = espprint_decode_hex(ndo, sa->secret, sizeof(sa->secret), colon);
383 if(sa->secretlen == 0) return 0;
387 if (i < sizeof(sa->secret)) {
388 memcpy(sa->secret, colon, i);
391 memcpy(sa->secret, colon, sizeof(sa->secret));
392 sa->secretlen = sizeof(sa->secret);
401 * for the moment, ignore the auth algorith, just hard code the authenticator
402 * length. Need to research how openssl looks up HMAC stuff.
405 espprint_decode_authalgo(netdissect_options *ndo,
406 char *decode, struct sa_list *sa)
410 colon = strchr(decode, ':');
412 (*ndo->ndo_warning)(ndo, "failed to decode espsecret: %s\n", decode);
417 if(ascii_strcasecmp(colon,"sha1") == 0 ||
418 ascii_strcasecmp(colon,"md5") == 0) {
424 static void esp_print_decode_ikeline(netdissect_options *ndo, char *line,
425 const char *file, int lineno)
427 /* it's an IKEv2 secret, store it instead */
431 char *icookie, *rcookie;
436 init = strsep(&line, " \t");
437 icookie = strsep(&line, " \t");
438 rcookie = strsep(&line, " \t");
439 authkey = strsep(&line, " \t");
440 enckey = strsep(&line, " \t");
442 /* if any fields are missing */
443 if(!init || !icookie || !rcookie || !authkey || !enckey) {
444 (*ndo->ndo_warning)(ndo, "print_esp: failed to find all fields for ikev2 at %s:%u",
450 ilen = strlen(icookie);
451 rlen = strlen(rcookie);
453 if((init[0]!='I' && init[0]!='R')
454 || icookie[0]!='0' || icookie[1]!='x'
455 || rcookie[0]!='0' || rcookie[1]!='x'
458 (*ndo->ndo_warning)(ndo, "print_esp: line %s:%u improperly formatted.",
461 (*ndo->ndo_warning)(ndo, "init=%s icookie=%s(%u) rcookie=%s(%u)",
462 init, icookie, ilen, rcookie, rlen);
468 sa1.initiator = (init[0] == 'I');
469 if(espprint_decode_hex(ndo, sa1.spii, sizeof(sa1.spii), icookie+2)!=8)
472 if(espprint_decode_hex(ndo, sa1.spir, sizeof(sa1.spir), rcookie+2)!=8)
475 if(!espprint_decode_encalgo(ndo, enckey, &sa1)) return;
477 if(!espprint_decode_authalgo(ndo, authkey, &sa1)) return;
479 esp_print_addsa(ndo, &sa1, FALSE);
484 * special form: file /name
485 * causes us to go read from this file instead.
488 static void esp_print_decode_onesecret(netdissect_options *ndo, char *line,
489 const char *file, int lineno)
497 spikey = strsep(&line, " \t");
499 memset(&sa1, 0, sizeof(struct sa_list));
501 /* if there is only one token, then it is an algo:key token */
505 /* sa1.daddr.version = 0; */
506 /* memset(&sa1.daddr, 0, sizeof(sa1.daddr)); */
512 if (spikey && ascii_strcasecmp(spikey, "file") == 0) {
513 /* open file and read it */
516 int subfile_lineno=0;
518 char *filename = line;
520 secretfile = fopen(filename, FOPEN_READ_TXT);
521 if (secretfile == NULL) {
522 (*ndo->ndo_error)(ndo, "print_esp: can't open %s: %s\n",
523 filename, strerror(errno));
527 while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {
529 /* remove newline from the line */
530 nl = strchr(fileline, '\n');
533 if (fileline[0] == '#') continue;
534 if (fileline[0] == '\0') continue;
536 esp_print_decode_onesecret(ndo, fileline, filename, subfile_lineno);
543 if (spikey && ascii_strcasecmp(spikey, "ikev2") == 0) {
544 esp_print_decode_ikeline(ndo, line, file, lineno);
553 spistr = strsep(&spikey, "@");
555 spino = strtoul(spistr, &foo, 0);
556 if (spistr == foo || !spikey) {
557 (*ndo->ndo_warning)(ndo, "print_esp: failed to decode spi# %s\n", foo);
563 if (strtoaddr6(spikey, &sa1.daddr.in6) == 1) {
564 sa1.daddr_version = 6;
565 } else if (strtoaddr(spikey, &sa1.daddr.in4) == 1) {
566 sa1.daddr_version = 4;
568 (*ndo->ndo_warning)(ndo, "print_esp: can not decode IP# %s\n", spikey);
574 /* skip any blank spaces */
575 while (isspace((unsigned char)*decode))
578 if(!espprint_decode_encalgo(ndo, decode, &sa1)) {
583 esp_print_addsa(ndo, &sa1, sa_def);
586 USES_APPLE_DEPRECATED_API
587 static void esp_init(netdissect_options *ndo _U_)
590 * 0.9.6 doesn't appear to define OPENSSL_API_COMPAT, so
591 * we check whether it's undefined or it's less than the
594 #if !defined(OPENSSL_API_COMPAT) || OPENSSL_API_COMPAT < 0x10100000L
595 OpenSSL_add_all_algorithms();
597 EVP_add_cipher_alias(SN_des_ede3_cbc, "3des");
601 void esp_print_decodesecret(netdissect_options *ndo)
605 static int initialized = 0;
612 p = ndo->ndo_espsecret;
614 while (p && p[0] != '\0') {
615 /* pick out the first line or first thing until a comma */
616 if ((line = strsep(&p, "\n,")) == NULL) {
621 esp_print_decode_onesecret(ndo, line, "cmdline", 0);
624 ndo->ndo_espsecret = NULL;
629 #ifdef HAVE_LIBCRYPTO
630 USES_APPLE_DEPRECATED_API
633 esp_print(netdissect_options *ndo,
634 const u_char *bp, const int length, const u_char *bp2
635 #ifndef HAVE_LIBCRYPTO
640 #ifndef HAVE_LIBCRYPTO
645 #ifndef HAVE_LIBCRYPTO
650 register const struct newesp *esp;
651 register const u_char *ep;
652 #ifdef HAVE_LIBCRYPTO
654 struct sa_list *sa = NULL;
655 const struct ip6_hdr *ip6 = NULL;
663 unsigned int block_size, output_buffer_size;
664 u_char *output_buffer;
667 esp = (const struct newesp *)bp;
669 #ifdef HAVE_LIBCRYPTO
675 /* keep secret out of a register */
676 p = (u_char *)&secret;
679 /* 'ep' points to the end of available data. */
680 ep = ndo->ndo_snapend;
682 if ((const u_char *)(esp + 1) >= ep) {
683 ND_PRINT((ndo, "[|ESP]"));
686 ND_PRINT((ndo, "ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi)));
687 ND_PRINT((ndo, ",seq=0x%x)", EXTRACT_32BITS(&esp->esp_seq)));
688 ND_PRINT((ndo, ", length %u", length));
690 #ifndef HAVE_LIBCRYPTO
693 /* initiailize SAs */
694 if (ndo->ndo_sa_list_head == NULL) {
695 if (!ndo->ndo_espsecret)
698 esp_print_decodesecret(ndo);
701 if (ndo->ndo_sa_list_head == NULL)
704 ip = (const struct ip *)bp2;
707 ip6 = (const struct ip6_hdr *)bp2;
708 /* we do not attempt to decrypt jumbograms */
709 if (!EXTRACT_16BITS(&ip6->ip6_plen))
711 /* if we can't get nexthdr, we do not need to decrypt it */
712 len = sizeof(struct ip6_hdr) + EXTRACT_16BITS(&ip6->ip6_plen);
714 /* see if we can find the SA, and if so, decode it */
715 for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
716 if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) &&
717 sa->daddr_version == 6 &&
718 UNALIGNED_MEMCMP(&sa->daddr.in6, &ip6->ip6_dst,
719 sizeof(struct in6_addr)) == 0) {
725 /* nexthdr & padding are in the last fragment */
726 if (EXTRACT_16BITS(&ip->ip_off) & IP_MF)
728 len = EXTRACT_16BITS(&ip->ip_len);
730 /* see if we can find the SA, and if so, decode it */
731 for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
732 if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) &&
733 sa->daddr_version == 4 &&
734 UNALIGNED_MEMCMP(&sa->daddr.in4, &ip->ip_dst,
735 sizeof(struct in_addr)) == 0) {
744 /* if we didn't find the specific one, then look for
745 * an unspecified one.
748 sa = ndo->ndo_sa_default;
750 /* if not found fail */
754 /* if we can't get nexthdr, we do not need to decrypt it */
757 if (ep - bp2 > len) {
758 /* FCS included at end of frame (NetBSD 1.6 or later) */
762 /* pointer to the IV, if there is one */
763 ivoff = (const u_char *)(esp + 1) + 0;
764 /* length of the IV, if there is one; 0, if there isn't */
767 ep = ep - sa->authlen;
770 ctx = EVP_CIPHER_CTX_new();
772 if (set_cipher_parameters(ctx, sa->evp, secret, NULL, 0) < 0)
773 (*ndo->ndo_warning)(ndo, "espkey init failed");
776 set_cipher_parameters(ctx, NULL, NULL, p, 0);
777 len = ep - (p + ivlen);
780 * Allocate a buffer for the decrypted data.
781 * The output buffer must be separate from the
782 * input buffer, and its size must be a multiple
783 * of the cipher block size.
785 block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx);
786 output_buffer_size = len + (block_size - len % block_size);
787 output_buffer = (u_char *)malloc(output_buffer_size);
788 if (output_buffer == NULL) {
789 (*ndo->ndo_warning)(ndo, "can't allocate memory for decryption buffer");
790 EVP_CIPHER_CTX_free(ctx);
794 EVP_Cipher(ctx, output_buffer, p + ivlen, len);
795 EVP_CIPHER_CTX_free(ctx);
797 * XXX - of course this is wrong, because buf is a
798 * const buffer, but changing this would require a
799 * more complicated fix.
801 memcpy(__DECONST(u_char *, p + ivlen), output_buffer, len);
803 advance = ivoff - (const u_char *)esp + ivlen;
805 advance = sizeof(struct newesp);
807 advance = sizeof(struct newesp);
809 /* sanity check for pad length */
810 if (ep - bp < *(ep - 2))
814 *padlen = *(ep - 2) + 2;
819 ND_PRINT((ndo, ": "));
826 #ifdef HAVE_LIBCRYPTO
832 * c-style: whitesmith