X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/31a13fa966c5033e87dbce103c015fd8f3f486ef..d7b497cac78b6e22a66a6bae9bdec60a8044f67a:/print-esp.c diff --git a/print-esp.c b/print-esp.c index c06543f5..d71bd23e 100644 --- a/print-esp.c +++ b/print-esp.c @@ -21,290 +21,815 @@ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ -#ifndef lint -static const char rcsid[] = - "@(#) $Header: /tcpdump/master/tcpdump/print-esp.c,v 1.19 2001-08-20 17:52:38 fenner Exp $ (LBL)"; -#endif +/* \summary: IPSEC Encapsulating Security Payload (ESP) printer */ #ifdef HAVE_CONFIG_H #include "config.h" #endif -#include -#include -#include -#include -#include +#include -#include +#include +#include +/* Any code in this file that depends on HAVE_LIBCRYPTO depends on + * HAVE_OPENSSL_EVP_H too. Undefining the former when the latter isn't defined + * is the simplest way of handling the dependency. + */ #ifdef HAVE_LIBCRYPTO -#include -#include -#ifdef HAVE_RC5_H -#include -#endif -#ifdef HAVE_CAST_H -#include +#ifdef HAVE_OPENSSL_EVP_H +#include +#else +#undef HAVE_LIBCRYPTO #endif #endif -#include +#include "netdissect.h" +#include "strtoaddr.h" +#include "extract.h" + +#include "ascii_strcasecmp.h" #include "ip.h" -#include "esp.h" -#ifdef INET6 #include "ip6.h" + +/* + * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * RFC1827/2406 Encapsulated Security Payload. + */ + +struct newesp { + uint32_t esp_spi; /* ESP */ + uint32_t esp_seq; /* Sequence number */ + /*variable size*/ /* (IV and) Payload data */ + /*variable size*/ /* padding */ + /*8bit*/ /* pad size */ + /*8bit*/ /* next header */ + /*8bit*/ /* next header */ + /*variable size, 32bit bound*/ /* Authentication data */ +}; + +#ifdef HAVE_LIBCRYPTO +union inaddr_u { + struct in_addr in4; + struct in6_addr in6; +}; +struct sa_list { + struct sa_list *next; + u_int daddr_version; + union inaddr_u daddr; + uint32_t spi; /* if == 0, then IKEv2 */ + int initiator; + u_char spii[8]; /* for IKEv2 */ + u_char spir[8]; + const EVP_CIPHER *evp; + int ivlen; + int authlen; + u_char authsecret[256]; + int authsecret_len; + u_char secret[256]; /* is that big enough for all secrets? */ + int secretlen; +}; + +#ifndef HAVE_EVP_CIPHER_CTX_NEW +/* + * Allocate an EVP_CIPHER_CTX. + * Used if we have an older version of OpenSSL that doesn't provide + * routines to allocate and free them. + */ +static EVP_CIPHER_CTX * +EVP_CIPHER_CTX_new(void) +{ + EVP_CIPHER_CTX *ctx; + + ctx = malloc(sizeof(*ctx)); + if (ctx == NULL) + return (NULL); + memset(ctx, 0, sizeof(*ctx)); + return (ctx); +} + +static void +EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx) +{ + EVP_CIPHER_CTX_cleanup(ctx); + free(ctx); +} +#endif + +#ifdef HAVE_EVP_CIPHERINIT_EX +/* + * Initialize the cipher by calling EVP_CipherInit_ex(), because + * calling EVP_CipherInit() will reset the cipher context, clearing + * the cipher, so calling it twice, with the second call having a + * null cipher, will clear the already-set cipher. EVP_CipherInit_ex(), + * however, won't reset the cipher context, so you can use it to specify + * the IV oin a second call after a first call to EVP_CipherInit_ex() + * to set the cipher and the key. + * + * XXX - is there some reason why we need to make two calls? + */ +static int +set_cipher_parameters(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, + const unsigned char *key, + const unsigned char *iv, int enc) +{ + return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc); +} +#else +/* + * Initialize the cipher by calling EVP_CipherInit(), because we don't + * have EVP_CipherInit_ex(); we rely on it not trashing the context. + */ +static int +set_cipher_parameters(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, + const unsigned char *key, + const unsigned char *iv, int enc) +{ + return EVP_CipherInit(ctx, cipher, key, iv, enc); +} +#endif + +/* + * this will adjust ndo_packetp and ndo_snapend to new buffer! + */ +USES_APPLE_DEPRECATED_API +int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo, + int initiator, + u_char spii[8], u_char spir[8], + const u_char *buf, const u_char *end) +{ + struct sa_list *sa; + const u_char *iv; + unsigned int len; + EVP_CIPHER_CTX *ctx; + unsigned int block_size, output_buffer_size; + u_char *output_buffer; + + /* initiator arg is any non-zero value */ + if(initiator) initiator=1; + + /* see if we can find the SA, and if so, decode it */ + for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) { + if (sa->spi == 0 + && initiator == sa->initiator + && memcmp(spii, sa->spii, 8) == 0 + && memcmp(spir, sa->spir, 8) == 0) + break; + } + + if(sa == NULL) return 0; + if(sa->evp == NULL) return 0; + + /* + * remove authenticator, and see if we still have something to + * work with + */ + end = end - sa->authlen; + iv = buf; + buf = buf + sa->ivlen; + len = end-buf; + + if(end <= buf) return 0; + + ctx = EVP_CIPHER_CTX_new(); + if (ctx == NULL) + return 0; + if (set_cipher_parameters(ctx, sa->evp, sa->secret, NULL, 0) < 0) + (*ndo->ndo_warning)(ndo, "espkey init failed"); + set_cipher_parameters(ctx, NULL, NULL, iv, 0); + /* + * Allocate a buffer for the decrypted data. + * The output buffer must be separate from the input buffer, and + * its size must be a multiple of the cipher block size. + */ + block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx); + output_buffer_size = len + (block_size - len % block_size); + output_buffer = (u_char *)malloc(output_buffer_size); + if (output_buffer == NULL) { + (*ndo->ndo_warning)(ndo, "can't allocate memory for decryption buffer"); + EVP_CIPHER_CTX_free(ctx); + return 0; + } + EVP_Cipher(ctx, output_buffer, buf, len); + EVP_CIPHER_CTX_free(ctx); + + /* + * XXX - of course this is wrong, because buf is a const buffer, + * but changing this would require a more complicated fix. + */ + memcpy(buf, output_buffer, len); + free(output_buffer); + + ndo->ndo_packetp = buf; + ndo->ndo_snapend = end; + + return 1; +} +USES_APPLE_RST + +static void esp_print_addsa(netdissect_options *ndo, + struct sa_list *sa, int sa_def) +{ + /* copy the "sa" */ + + struct sa_list *nsa; + + nsa = (struct sa_list *)malloc(sizeof(struct sa_list)); + if (nsa == NULL) + (*ndo->ndo_error)(ndo, "ran out of memory to allocate sa structure"); + + *nsa = *sa; + + if (sa_def) + ndo->ndo_sa_default = nsa; + + nsa->next = ndo->ndo_sa_list_head; + ndo->ndo_sa_list_head = nsa; +} + + +static u_int hexdigit(netdissect_options *ndo, char hex) +{ + if (hex >= '0' && hex <= '9') + return (hex - '0'); + else if (hex >= 'A' && hex <= 'F') + return (hex - 'A' + 10); + else if (hex >= 'a' && hex <= 'f') + return (hex - 'a' + 10); + else { + (*ndo->ndo_error)(ndo, "invalid hex digit %c in espsecret\n", hex); + return 0; + } +} + +static u_int hex2byte(netdissect_options *ndo, char *hexstring) +{ + u_int byte; + + byte = (hexdigit(ndo, hexstring[0]) << 4) + hexdigit(ndo, hexstring[1]); + return byte; +} + +/* + * returns size of binary, 0 on failure. + */ +static +int espprint_decode_hex(netdissect_options *ndo, + u_char *binbuf, unsigned int binbuf_len, + char *hex) +{ + unsigned int len; + int i; + + len = strlen(hex) / 2; + + if (len > binbuf_len) { + (*ndo->ndo_warning)(ndo, "secret is too big: %d\n", len); + return 0; + } + + i = 0; + while (hex[0] != '\0' && hex[1]!='\0') { + binbuf[i] = hex2byte(ndo, hex); + hex += 2; + i++; + } + + return i; +} + +/* + * decode the form: SPINUM@IP ALGONAME:0xsecret + */ + +USES_APPLE_DEPRECATED_API +static int +espprint_decode_encalgo(netdissect_options *ndo, + char *decode, struct sa_list *sa) +{ + size_t i; + const EVP_CIPHER *evp; + int authlen = 0; + char *colon, *p; + + colon = strchr(decode, ':'); + if (colon == NULL) { + (*ndo->ndo_warning)(ndo, "failed to decode espsecret: %s\n", decode); + return 0; + } + *colon = '\0'; + + if (strlen(decode) > strlen("-hmac96") && + !strcmp(decode + strlen(decode) - strlen("-hmac96"), + "-hmac96")) { + p = strstr(decode, "-hmac96"); + *p = '\0'; + authlen = 12; + } + if (strlen(decode) > strlen("-cbc") && + !strcmp(decode + strlen(decode) - strlen("-cbc"), "-cbc")) { + p = strstr(decode, "-cbc"); + *p = '\0'; + } + evp = EVP_get_cipherbyname(decode); + + if (!evp) { + (*ndo->ndo_warning)(ndo, "failed to find cipher algo %s\n", decode); + sa->evp = NULL; + sa->authlen = 0; + sa->ivlen = 0; + return 0; + } + + sa->evp = evp; + sa->authlen = authlen; + sa->ivlen = EVP_CIPHER_iv_length(evp); + + colon++; + if (colon[0] == '0' && colon[1] == 'x') { + /* decode some hex! */ + + colon += 2; + sa->secretlen = espprint_decode_hex(ndo, sa->secret, sizeof(sa->secret), colon); + if(sa->secretlen == 0) return 0; + } else { + i = strlen(colon); + + if (i < sizeof(sa->secret)) { + memcpy(sa->secret, colon, i); + sa->secretlen = i; + } else { + memcpy(sa->secret, colon, sizeof(sa->secret)); + sa->secretlen = sizeof(sa->secret); + } + } + + return 1; +} +USES_APPLE_RST + +/* + * for the moment, ignore the auth algorith, just hard code the authenticator + * length. Need to research how openssl looks up HMAC stuff. + */ +static int +espprint_decode_authalgo(netdissect_options *ndo, + char *decode, struct sa_list *sa) +{ + char *colon; + + colon = strchr(decode, ':'); + if (colon == NULL) { + (*ndo->ndo_warning)(ndo, "failed to decode espsecret: %s\n", decode); + return 0; + } + *colon = '\0'; + + if(ascii_strcasecmp(colon,"sha1") == 0 || + ascii_strcasecmp(colon,"md5") == 0) { + sa->authlen = 12; + } + return 1; +} + +static void esp_print_decode_ikeline(netdissect_options *ndo, char *line, + const char *file, int lineno) +{ + /* it's an IKEv2 secret, store it instead */ + struct sa_list sa1; + + char *init; + char *icookie, *rcookie; + int ilen, rlen; + char *authkey; + char *enckey; + + init = strsep(&line, " \t"); + icookie = strsep(&line, " \t"); + rcookie = strsep(&line, " \t"); + authkey = strsep(&line, " \t"); + enckey = strsep(&line, " \t"); + + /* if any fields are missing */ + if(!init || !icookie || !rcookie || !authkey || !enckey) { + (*ndo->ndo_warning)(ndo, "print_esp: failed to find all fields for ikev2 at %s:%u", + file, lineno); + + return; + } + + ilen = strlen(icookie); + rlen = strlen(rcookie); + + if((init[0]!='I' && init[0]!='R') + || icookie[0]!='0' || icookie[1]!='x' + || rcookie[0]!='0' || rcookie[1]!='x' + || ilen!=18 + || rlen!=18) { + (*ndo->ndo_warning)(ndo, "print_esp: line %s:%u improperly formatted.", + file, lineno); + + (*ndo->ndo_warning)(ndo, "init=%s icookie=%s(%u) rcookie=%s(%u)", + init, icookie, ilen, rcookie, rlen); + + return; + } + + sa1.spi = 0; + sa1.initiator = (init[0] == 'I'); + if(espprint_decode_hex(ndo, sa1.spii, sizeof(sa1.spii), icookie+2)!=8) + return; + + if(espprint_decode_hex(ndo, sa1.spir, sizeof(sa1.spir), rcookie+2)!=8) + return; + + if(!espprint_decode_encalgo(ndo, enckey, &sa1)) return; + + if(!espprint_decode_authalgo(ndo, authkey, &sa1)) return; + + esp_print_addsa(ndo, &sa1, FALSE); +} + +/* + * + * special form: file /name + * causes us to go read from this file instead. + * + */ +static void esp_print_decode_onesecret(netdissect_options *ndo, char *line, + const char *file, int lineno) +{ + struct sa_list sa1; + int sa_def; + + char *spikey; + char *decode; + + spikey = strsep(&line, " \t"); + sa_def = 0; + memset(&sa1, 0, sizeof(struct sa_list)); + + /* if there is only one token, then it is an algo:key token */ + if (line == NULL) { + decode = spikey; + spikey = NULL; + /* sa1.daddr.version = 0; */ + /* memset(&sa1.daddr, 0, sizeof(sa1.daddr)); */ + /* sa1.spi = 0; */ + sa_def = 1; + } else + decode = line; + + if (spikey && ascii_strcasecmp(spikey, "file") == 0) { + /* open file and read it */ + FILE *secretfile; + char fileline[1024]; + int subfile_lineno=0; + char *nl; + char *filename = line; + + secretfile = fopen(filename, FOPEN_READ_TXT); + if (secretfile == NULL) { + (*ndo->ndo_error)(ndo, "print_esp: can't open %s: %s\n", + filename, strerror(errno)); + return; + } + + while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) { + subfile_lineno++; + /* remove newline from the line */ + nl = strchr(fileline, '\n'); + if (nl) + *nl = '\0'; + if (fileline[0] == '#') continue; + if (fileline[0] == '\0') continue; + + esp_print_decode_onesecret(ndo, fileline, filename, subfile_lineno); + } + fclose(secretfile); + + return; + } + + if (spikey && ascii_strcasecmp(spikey, "ikev2") == 0) { + esp_print_decode_ikeline(ndo, line, file, lineno); + return; + } + + if (spikey) { + + char *spistr, *foo; + uint32_t spino; + + spistr = strsep(&spikey, "@"); + + spino = strtoul(spistr, &foo, 0); + if (spistr == foo || !spikey) { + (*ndo->ndo_warning)(ndo, "print_esp: failed to decode spi# %s\n", foo); + return; + } + + sa1.spi = spino; + + if (strtoaddr6(spikey, &sa1.daddr.in6) == 1) { + sa1.daddr_version = 6; + } else if (strtoaddr(spikey, &sa1.daddr.in4) == 1) { + sa1.daddr_version = 4; + } else { + (*ndo->ndo_warning)(ndo, "print_esp: can not decode IP# %s\n", spikey); + return; + } + } + + if (decode) { + /* skip any blank spaces */ + while (isspace((unsigned char)*decode)) + decode++; + + if(!espprint_decode_encalgo(ndo, decode, &sa1)) { + return; + } + } + + esp_print_addsa(ndo, &sa1, sa_def); +} + +USES_APPLE_DEPRECATED_API +static void esp_init(netdissect_options *ndo _U_) +{ + /* + * 0.9.6 doesn't appear to define OPENSSL_API_COMPAT, so + * we check whether it's undefined or it's less than the + * value for 1.1.0. + */ +#if !defined(OPENSSL_API_COMPAT) || OPENSSL_API_COMPAT < 0x10100000L + OpenSSL_add_all_algorithms(); #endif + EVP_add_cipher_alias(SN_des_ede3_cbc, "3des"); +} +USES_APPLE_RST -#include "interface.h" -#include "addrtoname.h" +void esp_print_decodesecret(netdissect_options *ndo) +{ + char *line; + char *p; + static int initialized = 0; + + if (!initialized) { + esp_init(ndo); + initialized = 1; + } + + p = ndo->ndo_espsecret; + + while (p && p[0] != '\0') { + /* pick out the first line or first thing until a comma */ + if ((line = strsep(&p, "\n,")) == NULL) { + line = p; + p = NULL; + } + + esp_print_decode_onesecret(ndo, line, "cmdline", 0); + } + ndo->ndo_espsecret = NULL; +} + +#endif + +#ifdef HAVE_LIBCRYPTO +USES_APPLE_DEPRECATED_API +#endif int -esp_print(register const u_char *bp, register const u_char *bp2, int *nhdr, int *padlen) +esp_print(netdissect_options *ndo, + const u_char *bp, const int length, const u_char *bp2 +#ifndef HAVE_LIBCRYPTO + _U_ +#endif + , + u_int *nhdr +#ifndef HAVE_LIBCRYPTO + _U_ +#endif + , + u_int *padlen +#ifndef HAVE_LIBCRYPTO + _U_ +#endif + ) { - register const struct esp *esp; + register const struct newesp *esp; register const u_char *ep; - u_int32_t spi; - enum { NONE, DESCBC, BLOWFISH, RC5, CAST128, DES3CBC } algo = NONE; - struct ip *ip = NULL; -#ifdef INET6 - struct ip6_hdr *ip6 = NULL; -#endif +#ifdef HAVE_LIBCRYPTO + const struct ip *ip; + struct sa_list *sa = NULL; + const struct ip6_hdr *ip6 = NULL; int advance; int len; - char *secret = NULL; + u_char *secret; int ivlen = 0; - u_char *ivoff; + const u_char *ivoff; + const u_char *p; + EVP_CIPHER_CTX *ctx; + unsigned int block_size, output_buffer_size; + u_char *output_buffer; +#endif + + esp = (const struct newesp *)bp; + +#ifdef HAVE_LIBCRYPTO + secret = NULL; + advance = 0; +#endif - esp = (struct esp *)bp; - spi = (u_int32_t)ntohl(esp->esp_spi); +#if 0 + /* keep secret out of a register */ + p = (u_char *)&secret; +#endif /* 'ep' points to the end of available data. */ - ep = snapend; + ep = ndo->ndo_snapend; - if ((u_char *)(esp + 1) >= ep - sizeof(struct esp)) { - fputs("[|ESP]", stdout); + if ((const u_char *)(esp + 1) >= ep) { + ND_PRINT((ndo, "[|ESP]")); goto fail; } - printf("ESP(spi=0x%08x", spi); - printf(",seq=0x%x", (u_int32_t)ntohl(*(u_int32_t *)(esp + 1))); - printf(")"); + ND_PRINT((ndo, "ESP(spi=0x%08x", EXTRACT_BE_U_4(&esp->esp_spi))); + ND_PRINT((ndo, ",seq=0x%x)", EXTRACT_BE_U_4(&esp->esp_seq))); + ND_PRINT((ndo, ", length %u", length)); - /* if we don't have decryption key, we can't decrypt this packet. */ - if (!espsecret) - goto fail; +#ifndef HAVE_LIBCRYPTO + goto fail; +#else + /* initiailize SAs */ + if (ndo->ndo_sa_list_head == NULL) { + if (!ndo->ndo_espsecret) + goto fail; - if (strncmp(espsecret, "des-cbc:", 8) == 0 - && strlen(espsecret + 8) == 8) { - algo = DESCBC; - ivlen = 8; - secret = espsecret + 8; - } else if (strncmp(espsecret, "blowfish-cbc:", 13) == 0) { - algo = BLOWFISH; - ivlen = 8; - secret = espsecret + 13; - } else if (strncmp(espsecret, "rc5-cbc:", 8) == 0) { - algo = RC5; - ivlen = 8; - secret = espsecret + 8; - } else if (strncmp(espsecret, "cast128-cbc:", 12) == 0) { - algo = CAST128; - ivlen = 8; - secret = espsecret + 12; - } else if (strncmp(espsecret, "3des-cbc:", 9) == 0 - && strlen(espsecret + 9) == 24) { - algo = DES3CBC; - ivlen = 8; - secret = espsecret + 9; - } else if (strncmp(espsecret, "none:", 5) == 0) { - algo = NONE; - ivlen = 0; - secret = espsecret + 5; - } else if (strlen(espsecret) == 8) { - algo = DESCBC; - ivlen = 8; - secret = espsecret; - } else { - algo = NONE; - ivlen = 0; - secret = espsecret; + esp_print_decodesecret(ndo); } - ip = (struct ip *)bp2; + if (ndo->ndo_sa_list_head == NULL) + goto fail; + + ip = (const struct ip *)bp2; switch (IP_V(ip)) { -#ifdef INET6 case 6: - ip6 = (struct ip6_hdr *)bp2; - ip = NULL; + ip6 = (const struct ip6_hdr *)bp2; /* we do not attempt to decrypt jumbograms */ - if (!ntohs(ip6->ip6_plen)) + if (!EXTRACT_BE_U_2(&ip6->ip6_plen)) goto fail; /* if we can't get nexthdr, we do not need to decrypt it */ - len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); + len = sizeof(struct ip6_hdr) + EXTRACT_BE_U_2(&ip6->ip6_plen); + + /* see if we can find the SA, and if so, decode it */ + for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) { + if (sa->spi == EXTRACT_BE_U_4(&esp->esp_spi) && + sa->daddr_version == 6 && + UNALIGNED_MEMCMP(&sa->daddr.in6, &ip6->ip6_dst, + sizeof(struct in6_addr)) == 0) { + break; + } + } break; -#endif /*INET6*/ case 4: /* nexthdr & padding are in the last fragment */ - if (ntohs(ip->ip_off) & IP_MF) + if (EXTRACT_BE_U_2(&ip->ip_off) & IP_MF) goto fail; -#ifdef INET6 - ip6 = NULL; -#endif - len = ntohs(ip->ip_len); + len = EXTRACT_BE_U_2(&ip->ip_len); + + /* see if we can find the SA, and if so, decode it */ + for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) { + if (sa->spi == EXTRACT_BE_U_4(&esp->esp_spi) && + sa->daddr_version == 4 && + UNALIGNED_MEMCMP(&sa->daddr.in4, &ip->ip_dst, + sizeof(struct in_addr)) == 0) { + break; + } + } break; default: goto fail; } - /* if we can't get nexthdr, we do not need to decrypt it */ - if (ep - bp2 < len) - goto fail; - - if (Rflag) - ivoff = (u_char *)(esp + 1) + sizeof(u_int32_t); - else - ivoff = (u_char *)(esp + 1); - - switch (algo) { - case DESCBC: -#ifdef HAVE_LIBCRYPTO - { - u_char iv[8]; - des_key_schedule schedule; - u_char *p; - - switch (ivlen) { - case 4: - memcpy(iv, ivoff, 4); - memcpy(&iv[4], ivoff, 4); - p = &iv[4]; - *p++ ^= 0xff; - *p++ ^= 0xff; - *p++ ^= 0xff; - *p++ ^= 0xff; - break; - case 8: - memcpy(iv, ivoff, 8); - break; - default: - goto fail; - } - - des_check_key = 0; - des_set_key((void *)secret, schedule); - - p = ivoff + ivlen; - des_cbc_encrypt((void *)p, (void *)p, - (long)(ep - p), schedule, (void *)iv, - DES_DECRYPT); - advance = ivoff - (u_char *)esp + ivlen; - break; - } -#else - goto fail; -#endif /*HAVE_LIBCRYPTO*/ - - case BLOWFISH: -#ifdef HAVE_LIBCRYPTO - { - BF_KEY schedule; - u_char *p; - - BF_set_key(&schedule, strlen(secret), secret); + /* if we didn't find the specific one, then look for + * an unspecified one. + */ + if (sa == NULL) + sa = ndo->ndo_sa_default; - p = ivoff + ivlen; - BF_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff, - BF_DECRYPT); - advance = ivoff - (u_char *)esp + ivlen; - break; - } -#else + /* if not found fail */ + if (sa == NULL) goto fail; -#endif /*HAVE_LIBCRYPTO*/ - - case RC5: -#if defined(HAVE_LIBCRYPTO) && defined(HAVE_RC5_H) - { - RC5_32_KEY schedule; - u_char *p; - RC5_32_set_key(&schedule, strlen(secret), secret, - RC5_16_ROUNDS); - - p = ivoff + ivlen; - RC5_32_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff, - RC5_DECRYPT); - advance = ivoff - (u_char *)esp + ivlen; - break; - } -#else - goto fail; -#endif /*HAVE_LIBCRYPTO*/ - - case CAST128: -#if defined(HAVE_LIBCRYPTO) && defined(HAVE_CAST_H) && !defined(HAVE_BUGGY_CAST128) - { - CAST_KEY schedule; - u_char *p; - - CAST_set_key(&schedule, strlen(secret), secret); - - p = ivoff + ivlen; - CAST_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff, - CAST_DECRYPT); - advance = ivoff - (u_char *)esp + ivlen; - break; - } -#else - goto fail; -#endif /*HAVE_LIBCRYPTO*/ - - case DES3CBC: -#if defined(HAVE_LIBCRYPTO) - { - des_key_schedule s1, s2, s3; - u_char *p; - - des_check_key = 0; - des_set_key((void *)secret, s1); - des_set_key((void *)(secret + 8), s2); - des_set_key((void *)(secret + 16), s3); - - p = ivoff + ivlen; - des_ede3_cbc_encrypt((void *)p, (void *)p, - (long)(ep - p), s1, s2, s3, (void *)ivoff, DES_DECRYPT); - advance = ivoff - (u_char *)esp + ivlen; - break; - } -#else + /* if we can't get nexthdr, we do not need to decrypt it */ + if (ep - bp2 < len) goto fail; -#endif /*HAVE_LIBCRYPTO*/ - - case NONE: - default: - if (Rflag) - advance = sizeof(struct esp) + sizeof(u_int32_t); - else - advance = sizeof(struct esp); - break; + if (ep - bp2 > len) { + /* FCS included at end of frame (NetBSD 1.6 or later) */ + ep = bp2 + len; } + /* pointer to the IV, if there is one */ + ivoff = (const u_char *)(esp + 1) + 0; + /* length of the IV, if there is one; 0, if there isn't */ + ivlen = sa->ivlen; + secret = sa->secret; + ep = ep - sa->authlen; + + if (sa->evp) { + ctx = EVP_CIPHER_CTX_new(); + if (ctx != NULL) { + if (set_cipher_parameters(ctx, sa->evp, secret, NULL, 0) < 0) + (*ndo->ndo_warning)(ndo, "espkey init failed"); + + p = ivoff; + set_cipher_parameters(ctx, NULL, NULL, p, 0); + len = ep - (p + ivlen); + + /* + * Allocate a buffer for the decrypted data. + * The output buffer must be separate from the + * input buffer, and its size must be a multiple + * of the cipher block size. + */ + block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx); + output_buffer_size = len + (block_size - len % block_size); + output_buffer = (u_char *)malloc(output_buffer_size); + if (output_buffer == NULL) { + (*ndo->ndo_warning)(ndo, "can't allocate memory for decryption buffer"); + EVP_CIPHER_CTX_free(ctx); + return -1; + } + + EVP_Cipher(ctx, output_buffer, p + ivlen, len); + EVP_CIPHER_CTX_free(ctx); + /* + * XXX - of course this is wrong, because buf is a + * const buffer, but changing this would require a + * more complicated fix. + */ + memcpy(p + ivlen, output_buffer, len); + free(output_buffer); + advance = ivoff - (const u_char *)esp + ivlen; + } else + advance = sizeof(struct newesp); + } else + advance = sizeof(struct newesp); + /* sanity check for pad length */ - if (ep - bp < *(ep - 2)) + if (ep - bp < EXTRACT_U_1(ep - 2)) goto fail; if (padlen) - *padlen = *(ep - 2) + 2; + *padlen = EXTRACT_U_1(ep - 2) + 2; if (nhdr) - *nhdr = *(ep - 1); + *nhdr = EXTRACT_U_1(ep - 1); - printf(": "); + ND_PRINT((ndo, ": ")); return advance; +#endif fail: - if (nhdr) - *nhdr = -1; - return 65536; + return -1; } +#ifdef HAVE_LIBCRYPTO +USES_APPLE_RST +#endif + +/* + * Local Variables: + * c-style: whitesmith + * c-basic-offset: 8 + * End: + */