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, buffer_size;
195 u_char *input_buffer, *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 buffers for the encrypted and decrypted data.
231 * Both buffers' sizes must be a multiple of the cipher block
232 * size, and the output buffer must be separate from the input
235 block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx);
236 buffer_size = len + (block_size - len % block_size);
239 * Attempt to allocate the input buffer.
241 input_buffer = (u_char *)malloc(buffer_size);
242 if (input_buffer == NULL) {
243 EVP_CIPHER_CTX_free(ctx);
244 (*ndo->ndo_error)(ndo, "can't allocate memory for encrypted data buffer");
247 * Copy the input data to the encrypted data buffer, and pad it
250 memcpy(input_buffer, buf, len);
251 memset(input_buffer + len, 0, buffer_size - len);
254 * Attempt to allocate the output buffer.
256 output_buffer = (u_char *)malloc(buffer_size);
257 if (output_buffer == NULL) {
259 EVP_CIPHER_CTX_free(ctx);
260 (*ndo->ndo_error)(ndo, "can't allocate memory for decryption buffer");
262 EVP_Cipher(ctx, output_buffer, input_buffer, len);
263 EVP_CIPHER_CTX_free(ctx);
266 * XXX - of course this is wrong, because buf is a const buffer,
267 * but changing this would require a more complicated fix.
269 memcpy(__DECONST(u_char *, buf), output_buffer, len);
273 ndo->ndo_packetp = buf;
274 ndo->ndo_snapend = end;
280 static void esp_print_addsa(netdissect_options *ndo,
281 struct sa_list *sa, int sa_def)
287 nsa = (struct sa_list *)malloc(sizeof(struct sa_list));
289 (*ndo->ndo_error)(ndo, "ran out of memory to allocate sa structure");
294 ndo->ndo_sa_default = nsa;
296 nsa->next = ndo->ndo_sa_list_head;
297 ndo->ndo_sa_list_head = nsa;
301 static u_int hexdigit(netdissect_options *ndo, char hex)
303 if (hex >= '0' && hex <= '9')
305 else if (hex >= 'A' && hex <= 'F')
306 return (hex - 'A' + 10);
307 else if (hex >= 'a' && hex <= 'f')
308 return (hex - 'a' + 10);
310 (*ndo->ndo_error)(ndo, "invalid hex digit %c in espsecret\n", hex);
314 static u_int hex2byte(netdissect_options *ndo, char *hexstring)
318 byte = (hexdigit(ndo, hexstring[0]) << 4) + hexdigit(ndo, hexstring[1]);
323 * returns size of binary, 0 on failure.
326 int espprint_decode_hex(netdissect_options *ndo,
327 u_char *binbuf, unsigned int binbuf_len,
333 len = strlen(hex) / 2;
335 if (len > binbuf_len) {
336 (*ndo->ndo_warning)(ndo, "secret is too big: %d\n", len);
341 while (hex[0] != '\0' && hex[1]!='\0') {
342 binbuf[i] = hex2byte(ndo, hex);
351 * decode the form: SPINUM@IP <tab> ALGONAME:0xsecret
354 USES_APPLE_DEPRECATED_API
356 espprint_decode_encalgo(netdissect_options *ndo,
357 char *decode, struct sa_list *sa)
360 const EVP_CIPHER *evp;
364 colon = strchr(decode, ':');
366 (*ndo->ndo_warning)(ndo, "failed to decode espsecret: %s\n", decode);
371 if (strlen(decode) > strlen("-hmac96") &&
372 !strcmp(decode + strlen(decode) - strlen("-hmac96"),
374 p = strstr(decode, "-hmac96");
378 if (strlen(decode) > strlen("-cbc") &&
379 !strcmp(decode + strlen(decode) - strlen("-cbc"), "-cbc")) {
380 p = strstr(decode, "-cbc");
383 evp = EVP_get_cipherbyname(decode);
386 (*ndo->ndo_warning)(ndo, "failed to find cipher algo %s\n", decode);
394 sa->authlen = authlen;
395 sa->ivlen = EVP_CIPHER_iv_length(evp);
398 if (colon[0] == '0' && colon[1] == 'x') {
399 /* decode some hex! */
402 sa->secretlen = espprint_decode_hex(ndo, sa->secret, sizeof(sa->secret), colon);
403 if(sa->secretlen == 0) return 0;
407 if (i < sizeof(sa->secret)) {
408 memcpy(sa->secret, colon, i);
411 memcpy(sa->secret, colon, sizeof(sa->secret));
412 sa->secretlen = sizeof(sa->secret);
421 * for the moment, ignore the auth algorithm, just hard code the authenticator
422 * length. Need to research how openssl looks up HMAC stuff.
425 espprint_decode_authalgo(netdissect_options *ndo,
426 char *decode, struct sa_list *sa)
430 colon = strchr(decode, ':');
432 (*ndo->ndo_warning)(ndo, "failed to decode espsecret: %s\n", decode);
437 if(ascii_strcasecmp(colon,"sha1") == 0 ||
438 ascii_strcasecmp(colon,"md5") == 0) {
444 static void esp_print_decode_ikeline(netdissect_options *ndo, char *line,
445 const char *file, int lineno)
447 /* it's an IKEv2 secret, store it instead */
451 char *icookie, *rcookie;
456 init = strsep(&line, " \t");
457 icookie = strsep(&line, " \t");
458 rcookie = strsep(&line, " \t");
459 authkey = strsep(&line, " \t");
460 enckey = strsep(&line, " \t");
462 /* if any fields are missing */
463 if(!init || !icookie || !rcookie || !authkey || !enckey) {
464 (*ndo->ndo_warning)(ndo, "print_esp: failed to find all fields for ikev2 at %s:%u",
470 ilen = strlen(icookie);
471 rlen = strlen(rcookie);
473 if((init[0]!='I' && init[0]!='R')
474 || icookie[0]!='0' || icookie[1]!='x'
475 || rcookie[0]!='0' || rcookie[1]!='x'
478 (*ndo->ndo_warning)(ndo, "print_esp: line %s:%u improperly formatted.",
481 (*ndo->ndo_warning)(ndo, "init=%s icookie=%s(%u) rcookie=%s(%u)",
482 init, icookie, ilen, rcookie, rlen);
488 sa1.initiator = (init[0] == 'I');
489 if(espprint_decode_hex(ndo, sa1.spii, sizeof(sa1.spii), icookie+2)!=8)
492 if(espprint_decode_hex(ndo, sa1.spir, sizeof(sa1.spir), rcookie+2)!=8)
495 if(!espprint_decode_encalgo(ndo, enckey, &sa1)) return;
497 if(!espprint_decode_authalgo(ndo, authkey, &sa1)) return;
499 esp_print_addsa(ndo, &sa1, FALSE);
504 * special form: file /name
505 * causes us to go read from this file instead.
508 static void esp_print_decode_onesecret(netdissect_options *ndo, char *line,
509 const char *file, int lineno)
517 spikey = strsep(&line, " \t");
519 memset(&sa1, 0, sizeof(struct sa_list));
521 /* if there is only one token, then it is an algo:key token */
525 /* sa1.daddr.version = 0; */
526 /* memset(&sa1.daddr, 0, sizeof(sa1.daddr)); */
532 if (spikey && ascii_strcasecmp(spikey, "file") == 0) {
533 /* open file and read it */
536 int subfile_lineno=0;
538 char *filename = line;
540 secretfile = fopen(filename, FOPEN_READ_TXT);
541 if (secretfile == NULL) {
542 (*ndo->ndo_error)(ndo, "print_esp: can't open %s: %s\n",
543 filename, strerror(errno));
546 while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) {
548 /* remove newline from the line */
549 nl = strchr(fileline, '\n');
552 if (fileline[0] == '#') continue;
553 if (fileline[0] == '\0') continue;
555 esp_print_decode_onesecret(ndo, fileline, filename, subfile_lineno);
562 if (spikey && ascii_strcasecmp(spikey, "ikev2") == 0) {
563 esp_print_decode_ikeline(ndo, line, file, lineno);
572 spistr = strsep(&spikey, "@");
573 if (spistr == NULL) {
574 (*ndo->ndo_warning)(ndo, "print_esp: failed to find the @ token");
578 spino = strtoul(spistr, &foo, 0);
579 if (spistr == foo || !spikey) {
580 (*ndo->ndo_warning)(ndo, "print_esp: failed to decode spi# %s\n", foo);
586 if (strtoaddr6(spikey, &sa1.daddr.in6) == 1) {
587 sa1.daddr_version = 6;
588 } else if (strtoaddr(spikey, &sa1.daddr.in4) == 1) {
589 sa1.daddr_version = 4;
591 (*ndo->ndo_warning)(ndo, "print_esp: can not decode IP# %s\n", spikey);
597 /* skip any blank spaces */
598 while (isspace((unsigned char)*decode))
601 if(!espprint_decode_encalgo(ndo, decode, &sa1)) {
606 esp_print_addsa(ndo, &sa1, sa_def);
609 USES_APPLE_DEPRECATED_API
610 static void esp_init(netdissect_options *ndo _U_)
613 * 0.9.6 doesn't appear to define OPENSSL_API_COMPAT, so
614 * we check whether it's undefined or it's less than the
617 #if !defined(OPENSSL_API_COMPAT) || OPENSSL_API_COMPAT < 0x10100000L
618 OpenSSL_add_all_algorithms();
620 EVP_add_cipher_alias(SN_des_ede3_cbc, "3des");
624 void esp_print_decodesecret(netdissect_options *ndo)
628 static int initialized = 0;
635 p = ndo->ndo_espsecret;
637 while (p && p[0] != '\0') {
638 /* pick out the first line or first thing until a comma */
639 if ((line = strsep(&p, "\n,")) == NULL) {
644 esp_print_decode_onesecret(ndo, line, "cmdline", 0);
647 ndo->ndo_espsecret = NULL;
652 #ifdef HAVE_LIBCRYPTO
653 USES_APPLE_DEPRECATED_API
656 esp_print(netdissect_options *ndo,
657 const u_char *bp, const int length, const u_char *bp2
658 #ifndef HAVE_LIBCRYPTO
663 #ifndef HAVE_LIBCRYPTO
668 #ifndef HAVE_LIBCRYPTO
673 register const struct newesp *esp;
674 register const u_char *ep;
675 #ifdef HAVE_LIBCRYPTO
677 struct sa_list *sa = NULL;
678 const struct ip6_hdr *ip6 = NULL;
686 unsigned int block_size, buffer_size;
687 u_char *input_buffer, *output_buffer;
690 esp = (const struct newesp *)bp;
692 #ifdef HAVE_LIBCRYPTO
698 /* keep secret out of a register */
699 p = (u_char *)&secret;
702 /* 'ep' points to the end of available data. */
703 ep = ndo->ndo_snapend;
705 if ((const u_char *)(esp + 1) >= ep) {
706 ND_PRINT((ndo, "[|ESP]"));
709 ND_PRINT((ndo, "ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi)));
710 ND_PRINT((ndo, ",seq=0x%x)", EXTRACT_32BITS(&esp->esp_seq)));
711 ND_PRINT((ndo, ", length %u", length));
713 #ifndef HAVE_LIBCRYPTO
716 /* initiailize SAs */
717 if (ndo->ndo_sa_list_head == NULL) {
718 if (!ndo->ndo_espsecret)
721 esp_print_decodesecret(ndo);
724 if (ndo->ndo_sa_list_head == NULL)
727 ip = (const struct ip *)bp2;
730 ip6 = (const struct ip6_hdr *)bp2;
731 /* we do not attempt to decrypt jumbograms */
732 if (!EXTRACT_16BITS(&ip6->ip6_plen))
734 /* if we can't get nexthdr, we do not need to decrypt it */
735 len = sizeof(struct ip6_hdr) + EXTRACT_16BITS(&ip6->ip6_plen);
737 /* see if we can find the SA, and if so, decode it */
738 for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
739 if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) &&
740 sa->daddr_version == 6 &&
741 UNALIGNED_MEMCMP(&sa->daddr.in6, &ip6->ip6_dst,
742 sizeof(struct in6_addr)) == 0) {
748 /* nexthdr & padding are in the last fragment */
749 if (EXTRACT_16BITS(&ip->ip_off) & IP_MF)
751 len = EXTRACT_16BITS(&ip->ip_len);
753 /* see if we can find the SA, and if so, decode it */
754 for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) {
755 if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) &&
756 sa->daddr_version == 4 &&
757 UNALIGNED_MEMCMP(&sa->daddr.in4, &ip->ip_dst,
758 sizeof(struct in_addr)) == 0) {
767 /* if we didn't find the specific one, then look for
768 * an unspecified one.
771 sa = ndo->ndo_sa_default;
773 /* if not found fail */
777 /* if we can't get nexthdr, we do not need to decrypt it */
780 if (ep - bp2 > len) {
781 /* FCS included at end of frame (NetBSD 1.6 or later) */
785 /* pointer to the IV, if there is one */
786 ivoff = (const u_char *)(esp + 1) + 0;
787 /* length of the IV, if there is one; 0, if there isn't */
790 ep = ep - sa->authlen;
793 ctx = EVP_CIPHER_CTX_new();
795 if (set_cipher_parameters(ctx, sa->evp, secret, NULL, 0) < 0)
796 (*ndo->ndo_warning)(ndo, "espkey init failed");
799 set_cipher_parameters(ctx, NULL, NULL, p, 0);
800 len = ep - (p + ivlen);
803 * Allocate buffers for the encrypted and decrypted
804 * data. Both buffers' sizes must be a multiple of
805 * the cipher block size, and the output buffer must
806 * be separate from the input buffer.
808 block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx);
809 buffer_size = len + (block_size - len % block_size);
812 * Attempt to allocate the input buffer.
814 input_buffer = (u_char *)malloc(buffer_size);
815 if (input_buffer == NULL) {
816 EVP_CIPHER_CTX_free(ctx);
817 (*ndo->ndo_error)(ndo, "can't allocate memory for encrypted data buffer");
820 * Copy the input data to the encrypted data buffer,
821 * and pad it with zeroes.
823 memcpy(input_buffer, p + ivlen, len);
824 memset(input_buffer + len, 0, buffer_size - len);
827 * Attempt to allocate the output buffer.
829 output_buffer = (u_char *)malloc(buffer_size);
830 if (output_buffer == NULL) {
832 EVP_CIPHER_CTX_free(ctx);
833 (*ndo->ndo_error)(ndo, "can't allocate memory for decryption buffer");
836 EVP_Cipher(ctx, output_buffer, input_buffer, len);
838 EVP_CIPHER_CTX_free(ctx);
840 * XXX - of course this is wrong, because buf is a
841 * const buffer, but changing this would require a
842 * more complicated fix.
844 memcpy(__DECONST(u_char *, p + ivlen), output_buffer, len);
846 advance = ivoff - (const u_char *)esp + ivlen;
848 advance = sizeof(struct newesp);
850 advance = sizeof(struct newesp);
852 /* sanity check for pad length */
853 if (ep - bp < *(ep - 2))
857 *padlen = *(ep - 2) + 2;
862 ND_PRINT((ndo, ": "));
869 #ifdef HAVE_LIBCRYPTO
875 * c-style: whitesmith