X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/ec799d60f6cd3f41041b57efe3963c28dda94d4a..refs/heads/mcr-macro-update-1:/print-esp.c diff --git a/print-esp.c b/print-esp.c index ade654a3..14885d6b 100644 --- a/print-esp.c +++ b/print-esp.c @@ -21,62 +21,99 @@ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ -#ifndef lint -static const char rcsid[] _U_ = - "@(#) $Header: /tcpdump/master/tcpdump/print-esp.c,v 1.58 2007-12-07 00:03:07 mcr Exp $ (LBL)"; -#endif +/* \summary: IPSEC Encapsulating Security Payload (ESP) printer */ #ifdef HAVE_CONFIG_H -#include "config.h" +#include #endif -#include - -#include +#include "netdissect-stdinc.h" +#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 #ifdef HAVE_OPENSSL_EVP_H #include +#else +#undef HAVE_LIBCRYPTO #endif #endif -#include +#include "netdissect.h" +#include "extract.h" + +#ifdef HAVE_LIBCRYPTO +#include "strtoaddr.h" +#include "ascii_strcasecmp.h" +#endif #include "ip.h" -#include "esp.h" -#ifdef INET6 #include "ip6.h" -#endif -#include "netdissect.h" -#include "addrtoname.h" -#include "extract.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. + */ -#ifndef HAVE_SOCKADDR_STORAGE -#ifdef INET6 -struct sockaddr_storage { - union { - struct sockaddr_in sin; - struct sockaddr_in6 sin6; - } un; +struct newesp { + nd_uint32_t esp_spi; /* ESP */ + nd_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 */ }; -#else -#define sockaddr_storage sockaddr -#endif -#endif /* HAVE_SOCKADDR_STORAGE */ #ifdef HAVE_LIBCRYPTO +union inaddr_u { + nd_ipv4 in4; + nd_ipv6 in6; +}; struct sa_list { struct sa_list *next; - struct sockaddr_storage daddr; - u_int32_t spi; /* if == 0, then IKEv2 */ + 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; + u_int ivlen; int authlen; u_char authsecret[256]; int authsecret_len; @@ -84,22 +121,179 @@ struct sa_list { 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_DECRYPTINIT_EX +/* + * Initialize the cipher by calling EVP_DecryptInit_ex(), because + * calling EVP_DecryptInit() 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_DecryptInit_ex(), + * however, won't reset the cipher context, so you can use it to specify + * the IV in a second call after a first call to EVP_DecryptInit_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) +{ + return EVP_DecryptInit_ex(ctx, cipher, NULL, key, iv); +} +#else +/* + * Initialize the cipher by calling EVP_DecryptInit(), because we don't + * have EVP_DecryptInit_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) +{ + return EVP_DecryptInit(ctx, cipher, key, iv); +} +#endif + +static u_char * +do_decrypt(netdissect_options *ndo, const char *caller, struct sa_list *sa, + const u_char *iv, const u_char *ct, unsigned int ctlen) +{ + EVP_CIPHER_CTX *ctx; + unsigned int block_size; + unsigned int ptlen; + u_char *pt; + int len; + + ctx = EVP_CIPHER_CTX_new(); + if (ctx == NULL) { + /* + * Failed to initialize the cipher context. + * From a look at the OpenSSL code, this appears to + * mean "couldn't allocate memory for the cipher context"; + * note that we're not passing any parameters, so there's + * not much else it can mean. + */ + (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC, + "%s: can't allocate memory for cipher context", caller); + return NULL; + } + + if (set_cipher_parameters(ctx, sa->evp, sa->secret, NULL) < 0) { + EVP_CIPHER_CTX_free(ctx); + (*ndo->ndo_warning)(ndo, "%s: espkey init failed", caller); + return NULL; + } + if (set_cipher_parameters(ctx, NULL, NULL, iv) < 0) { + EVP_CIPHER_CTX_free(ctx); + (*ndo->ndo_warning)(ndo, "%s: IV init failed", caller); + return NULL; + } + + /* + * At least as I read RFC 5996 section 3.14 and RFC 4303 section 2.4, + * if the cipher has a block size of which the ciphertext's size must + * be a multiple, the payload must be padded to make that happen, so + * the ciphertext length must be a multiple of the block size. Fail + * if that's not the case. + */ + block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx); + if ((ctlen % block_size) != 0) { + EVP_CIPHER_CTX_free(ctx); + (*ndo->ndo_warning)(ndo, + "%s: ciphertext size %u is not a multiple of the cipher block size %u", + caller, ctlen, block_size); + return NULL; + } + + /* + * Attempt to allocate a buffer for the decrypted data, because + * we can't decrypt on top of the input buffer. + */ + ptlen = ctlen; + pt = (u_char *)malloc(ptlen); + if (pt == NULL) { + EVP_CIPHER_CTX_free(ctx); + (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC, + "%s: can't allocate memory for decryption buffer", caller); + return NULL; + } + + /* + * The size of the ciphertext handed to us is a multiple of the + * cipher block size, so we don't need to worry about padding. + */ + if (!EVP_CIPHER_CTX_set_padding(ctx, 0)) { + free(pt); + EVP_CIPHER_CTX_free(ctx); + (*ndo->ndo_warning)(ndo, + "%s: EVP_CIPHER_CTX_set_padding failed", caller); + return NULL; + } + if (!EVP_DecryptUpdate(ctx, pt, &len, ct, ctlen)) { + free(pt); + EVP_CIPHER_CTX_free(ctx); + (*ndo->ndo_warning)(ndo, "%s: EVP_DecryptUpdate failed", + caller); + return NULL; + } + EVP_CIPHER_CTX_free(ctx); + return pt; +} + /* - * this will adjust ndo_packetp and ndo_snapend to new buffer! + * This will allocate a new buffer containing the decrypted data. + * It returns 1 on success and 0 on failure. + * + * It will push the new buffer and the values of ndo->ndo_packetp and + * ndo->ndo_snapend onto the buffer stack, and change ndo->ndo_packetp + * and ndo->ndo_snapend to refer to the new buffer. + * + * Our caller must pop the buffer off the stack when it's finished + * dissecting anything in it and before it does any dissection of + * anything in the old buffer. That will free the new buffer. */ -int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo, +USES_APPLE_DEPRECATED_API +int esp_decrypt_buffer_by_ikev2_print(netdissect_options *ndo, int initiator, - u_char spii[8], u_char spir[8], - u_char *buf, u_char *end) + const u_char spii[8], + const u_char spir[8], + const u_char *buf, const u_char *end) { struct sa_list *sa; - u_char *iv; - int len; - EVP_CIPHER_CTX ctx; + const u_char *iv; + const u_char *ct; + unsigned int ctlen; + u_char *pt; /* 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 @@ -118,24 +312,29 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo, */ end = end - sa->authlen; iv = buf; - buf = buf + sa->ivlen; - len = end-buf; + ct = iv + sa->ivlen; + ctlen = end-ct; - if(end <= buf) return 0; + if(end <= ct) return 0; - memset(&ctx, 0, sizeof(ctx)); - if (EVP_CipherInit(&ctx, sa->evp, sa->secret, NULL, 0) < 0) - (*ndo->ndo_warning)(ndo, "espkey init failed"); - EVP_CipherInit(&ctx, NULL, NULL, iv, 0); - EVP_Cipher(&ctx, buf, buf, len); - EVP_CIPHER_CTX_cleanup(&ctx); + pt = do_decrypt(ndo, "esp_decrypt_buffer_by_ikev2_print", sa, iv, + ct, ctlen); + if (pt == NULL) + return 0; - ndo->ndo_packetp = buf; - ndo->ndo_snapend = end; + /* + * Switch to the output buffer for dissection, and save it + * on the buffer stack so it can be freed; our caller must + * pop it when done. + */ + if (!nd_push_buffer(ndo, pt, pt, pt + ctlen)) { + free(pt); + return 0; + } return 1; - } +USES_APPLE_RST static void esp_print_addsa(netdissect_options *ndo, struct sa_list *sa, int sa_def) @@ -144,9 +343,11 @@ static void esp_print_addsa(netdissect_options *ndo, struct sa_list *nsa; + /* malloc() return used in a 'struct sa_list': do not free() */ nsa = (struct sa_list *)malloc(sizeof(struct sa_list)); if (nsa == NULL) - (*ndo->ndo_error)(ndo, "ran out of memory to allocate sa structure"); + (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC, + "esp_print_addsa: malloc"); *nsa = *sa; @@ -167,8 +368,8 @@ static u_int hexdigit(netdissect_options *ndo, char hex) 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; + (*ndo->ndo_error)(ndo, S_ERR_ND_ESP_SECRET, + "invalid hex digit %c in espsecret\n", hex); } } @@ -192,12 +393,12 @@ int espprint_decode_hex(netdissect_options *ndo, int i; len = strlen(hex) / 2; - + if (len > binbuf_len) { - (*ndo->ndo_warning)(ndo, "secret is too big: %d\n", len); + (*ndo->ndo_warning)(ndo, "secret is too big: %u\n", len); return 0; } - + i = 0; while (hex[0] != '\0' && hex[1]!='\0') { binbuf[i] = hex2byte(ndo, hex); @@ -212,24 +413,23 @@ int espprint_decode_hex(netdissect_options *ndo, * 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) { - int len; 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'; - - len = colon - decode; + if (strlen(decode) > strlen("-hmac96") && !strcmp(decode + strlen(decode) - strlen("-hmac96"), "-hmac96")) { @@ -251,11 +451,12 @@ espprint_decode_encalgo(netdissect_options *ndo, sa->ivlen = 0; return 0; } - + sa->evp = evp; sa->authlen = authlen; + /* This returns an int, but it should never be negative */ sa->ivlen = EVP_CIPHER_iv_length(evp); - + colon++; if (colon[0] == '0' && colon[1] == 'x') { /* decode some hex! */ @@ -265,7 +466,7 @@ espprint_decode_encalgo(netdissect_options *ndo, if(sa->secretlen == 0) return 0; } else { i = strlen(colon); - + if (i < sizeof(sa->secret)) { memcpy(sa->secret, colon, i); sa->secretlen = i; @@ -277,9 +478,10 @@ espprint_decode_encalgo(netdissect_options *ndo, return 1; } +USES_APPLE_RST /* - * for the moment, ignore the auth algorith, just hard code the authenticator + * for the moment, ignore the auth algorithm, just hard code the authenticator * length. Need to research how openssl looks up HMAC stuff. */ static int @@ -294,9 +496,9 @@ espprint_decode_authalgo(netdissect_options *ndo, return 0; } *colon = '\0'; - - if(strcasecmp(colon,"sha1") == 0 || - strcasecmp(colon,"md5") == 0) { + + if(ascii_strcasecmp(decode,"sha1") == 0 || + ascii_strcasecmp(decode,"md5") == 0) { sa->authlen = 12; } return 1; @@ -313,21 +515,21 @@ static void esp_print_decode_ikeline(netdissect_options *ndo, char *line, 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); @@ -341,7 +543,7 @@ static void esp_print_decode_ikeline(netdissect_options *ndo, char *line, (*ndo->ndo_warning)(ndo, "init=%s icookie=%s(%u) rcookie=%s(%u)", init, icookie, ilen, rcookie, rlen); - + return; } @@ -356,7 +558,7 @@ static void esp_print_decode_ikeline(netdissect_options *ndo, char *line, if(!espprint_decode_encalgo(ndo, enckey, &sa1)) return; if(!espprint_decode_authalgo(ndo, authkey, &sa1)) return; - + esp_print_addsa(ndo, &sa1, FALSE); } @@ -383,28 +585,30 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line, 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 && strcasecmp(spikey, "file") == 0) { + if (spikey && ascii_strcasecmp(spikey, "file") == 0) { /* open file and read it */ FILE *secretfile; char fileline[1024]; - int lineno=0; + int subfile_lineno=0; char *nl; char *filename = line; secretfile = fopen(filename, FOPEN_READ_TXT); if (secretfile == NULL) { - perror(filename); - exit(3); + (*ndo->ndo_error)(ndo, S_ERR_ND_OPEN_FILE, + "print_esp: can't open %s: %s\n", + filename, strerror(errno)); } while (fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) { - lineno++; + subfile_lineno++; /* remove newline from the line */ nl = strchr(fileline, '\n'); if (nl) @@ -412,63 +616,52 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line, if (fileline[0] == '#') continue; if (fileline[0] == '\0') continue; - esp_print_decode_onesecret(ndo, fileline, filename, lineno); + esp_print_decode_onesecret(ndo, fileline, filename, subfile_lineno); } fclose(secretfile); return; } - if (spikey && strcasecmp(spikey, "ikev2") == 0) { + if (spikey && ascii_strcasecmp(spikey, "ikev2") == 0) { esp_print_decode_ikeline(ndo, line, file, lineno); return; - } + } if (spikey) { - + char *spistr, *foo; - u_int32_t spino; - struct sockaddr_in *sin; -#ifdef INET6 - struct sockaddr_in6 *sin6; -#endif - + uint32_t spino; + spistr = strsep(&spikey, "@"); - + if (spistr == NULL) { + (*ndo->ndo_warning)(ndo, "print_esp: failed to find the @ token"); + return; + } + 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; - - sin = (struct sockaddr_in *)&sa1.daddr; -#ifdef INET6 - sin6 = (struct sockaddr_in6 *)&sa1.daddr; - if (inet_pton(AF_INET6, spikey, &sin6->sin6_addr) == 1) { -#ifdef HAVE_SOCKADDR_SA_LEN - sin6->sin6_len = sizeof(struct sockaddr_in6); -#endif - sin6->sin6_family = AF_INET6; - } else -#endif - if (inet_pton(AF_INET, spikey, &sin->sin_addr) == 1) { -#ifdef HAVE_SOCKADDR_SA_LEN - sin->sin_len = sizeof(struct sockaddr_in); -#endif - sin->sin_family = AF_INET; - } else { - (*ndo->ndo_warning)(ndo, "print_esp: can not decode IP# %s\n", spikey); - return; - } + + 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)) + while (*decode == ' ' || *decode == '\t' || *decode == '\r' || *decode == '\n') decode++; - + if(!espprint_decode_encalgo(ndo, decode, &sa1)) { return; } @@ -477,14 +670,22 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line, 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 -void esp_print_decodesecret(netdissect_options *ndo) +void esp_decodesecret_print(netdissect_options *ndo) { char *line; char *p; @@ -512,121 +713,101 @@ void esp_print_decodesecret(netdissect_options *ndo) #endif -int -esp_print(netdissect_options *ndo, - const u_char *bp, const int length, const u_char *bp2 -#ifndef HAVE_LIBCRYPTO - _U_ -#endif - , - int *nhdr -#ifndef HAVE_LIBCRYPTO - _U_ +#ifdef HAVE_LIBCRYPTO +#define USED_IF_LIBCRYPTO +#else +#define USED_IF_LIBCRYPTO _U_ #endif - , - int *padlen -#ifndef HAVE_LIBCRYPTO - _U_ + +#ifdef HAVE_LIBCRYPTO +USES_APPLE_DEPRECATED_API #endif - ) +void +esp_print(netdissect_options *ndo, + const u_char *bp, u_int length, + const u_char *bp2 USED_IF_LIBCRYPTO, + u_int ver USED_IF_LIBCRYPTO, + int fragmented USED_IF_LIBCRYPTO, + u_int ttl_hl USED_IF_LIBCRYPTO) { - register const struct newesp *esp; - register const u_char *ep; + const struct newesp *esp; + const u_char *ep; #ifdef HAVE_LIBCRYPTO - struct ip *ip; + const struct ip *ip; struct sa_list *sa = NULL; - int espsecret_keylen; -#ifdef INET6 - struct ip6_hdr *ip6 = NULL; -#endif - int advance; - int len; - u_char *secret; - int ivlen = 0; - u_char *ivoff; - u_char *p; - EVP_CIPHER_CTX ctx; - int blocksz; + const struct ip6_hdr *ip6 = NULL; + const u_char *iv; + u_int ivlen; + u_int payloadlen; + const u_char *ct; + u_char *pt; + u_int padlen; + u_int nh; #endif - esp = (struct newesp *)bp; - -#ifdef HAVE_LIBCRYPTO - secret = NULL; - advance = 0; -#endif - -#if 0 - /* keep secret out of a register */ - p = (u_char *)&secret; -#endif + ndo->ndo_protocol = "esp"; + esp = (const struct newesp *)bp; /* 'ep' points to the end of available data. */ ep = ndo->ndo_snapend; - if ((u_char *)(esp + 1) >= ep) { - fputs("[|ESP]", stdout); - goto fail; + if ((const u_char *)(esp + 1) >= ep) { + nd_print_trunc(ndo); + return; } - (*ndo->ndo_printf)(ndo, "ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi)); - (*ndo->ndo_printf)(ndo, ",seq=0x%x)", EXTRACT_32BITS(&esp->esp_seq)); - (*ndo->ndo_printf)(ndo, ", length %u", length); + ND_PRINT("ESP(spi=0x%08x", GET_BE_U_4(esp->esp_spi)); + ND_PRINT(",seq=0x%x)", GET_BE_U_4(esp->esp_seq)); + ND_PRINT(", length %u", length); -#ifndef HAVE_LIBCRYPTO - goto fail; -#else +#ifdef HAVE_LIBCRYPTO /* initiailize SAs */ if (ndo->ndo_sa_list_head == NULL) { if (!ndo->ndo_espsecret) - goto fail; + return; - esp_print_decodesecret(ndo); + esp_decodesecret_print(ndo); } if (ndo->ndo_sa_list_head == NULL) - goto fail; + return; - ip = (struct ip *)bp2; - switch (IP_V(ip)) { -#ifdef INET6 + ip = (const struct ip *)bp2; + switch (ver) { case 6: - ip6 = (struct ip6_hdr *)bp2; + ip6 = (const struct ip6_hdr *)bp2; /* we do not attempt to decrypt jumbograms */ - if (!EXTRACT_16BITS(&ip6->ip6_plen)) - goto fail; + if (!GET_BE_U_2(ip6->ip6_plen)) + return; + /* XXX - check whether it's fragmented? */ /* if we can't get nexthdr, we do not need to decrypt it */ - len = sizeof(struct ip6_hdr) + EXTRACT_16BITS(&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) { - struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&sa->daddr; - if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) && - sin6->sin6_family == AF_INET6 && - memcmp(&sin6->sin6_addr, &ip6->ip6_dst, - sizeof(struct in6_addr)) == 0) { + if (sa->spi == GET_BE_U_4(esp->esp_spi) && + sa->daddr_version == 6 && + UNALIGNED_MEMCMP(&sa->daddr.in6, &ip6->ip6_dst, + sizeof(nd_ipv6)) == 0) { break; } } break; -#endif /*INET6*/ case 4: /* nexthdr & padding are in the last fragment */ - if (EXTRACT_16BITS(&ip->ip_off) & IP_MF) - goto fail; - len = EXTRACT_16BITS(&ip->ip_len); + if (fragmented) + return; /* see if we can find the SA, and if so, decode it */ for (sa = ndo->ndo_sa_list_head; sa != NULL; sa = sa->next) { - struct sockaddr_in *sin = (struct sockaddr_in *)&sa->daddr; - if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) && - sin->sin_family == AF_INET && - sin->sin_addr.s_addr == ip->ip_dst.s_addr) { + if (sa->spi == GET_BE_U_4(esp->esp_spi) && + sa->daddr_version == 4 && + UNALIGNED_MEMCMP(&sa->daddr.in4, &ip->ip_dst, + sizeof(nd_ipv4)) == 0) { break; } } break; default: - goto fail; + return; } /* if we didn't find the specific one, then look for @@ -634,61 +815,102 @@ esp_print(netdissect_options *ndo, */ if (sa == NULL) sa = ndo->ndo_sa_default; - + /* if not found fail */ if (sa == NULL) - goto fail; - - /* if we can't get nexthdr, we do not need to decrypt it */ - if (ep - bp2 < len) - goto fail; - if (ep - bp2 > len) { - /* FCS included at end of frame (NetBSD 1.6 or later) */ - ep = bp2 + len; - } + return; - ivoff = (u_char *)(esp + 1) + 0; + /* pointer to the IV, if there is one */ + iv = (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; - espsecret_keylen = sa->secretlen; + + /* + * Get a pointer to the ciphertext. + * + * p points to the beginning of the payload, i.e. to the + * initialization vector, so if we skip past the initialization + * vector, it points to the beginning of the ciphertext. + */ + ct = iv + ivlen; + + /* + * Make sure the authentication data/integrity check value length + * isn't bigger than the total amount of data available after + * the ESP header and initialization vector is removed and, + * if not, slice the authentication data/ICV off. + */ + if (ep - ct < sa->authlen) { + nd_print_trunc(ndo); + return; + } ep = ep - sa->authlen; - if (sa->evp) { - memset(&ctx, 0, sizeof(ctx)); - if (EVP_CipherInit(&ctx, sa->evp, secret, NULL, 0) < 0) - (*ndo->ndo_warning)(ndo, "espkey init failed"); + /* + * Calculate the length of the ciphertext. ep points to + * the beginning of the authentication data/integrity check + * value, i.e. right past the end of the ciphertext; + */ + payloadlen = ep - ct; + + if (sa->evp == NULL) + return; - blocksz = EVP_CIPHER_CTX_block_size(&ctx); + /* + * If the next header value is past the end of the available + * data, we won't be able to fetch it once we've decrypted + * the ciphertext, so there's no point in decrypting the data. + * + * Report it as truncation. + */ + if (!ND_TTEST_1(ep - 1)) { + nd_print_trunc(ndo); + return; + } - p = ivoff; - EVP_CipherInit(&ctx, NULL, NULL, p, 0); - EVP_Cipher(&ctx, p + ivlen, p + ivlen, ep - (p + ivlen)); - EVP_CIPHER_CTX_cleanup(&ctx); - advance = ivoff - (u_char *)esp + ivlen; - } else - advance = sizeof(struct newesp); + pt = do_decrypt(ndo, "esp_print", sa, iv, ct, payloadlen); + if (pt == NULL) + return; + + /* + * Switch to the output buffer for dissection, and + * save it on the buffer stack so it can be freed. + */ + ep = pt + payloadlen; + if (!nd_push_buffer(ndo, pt, pt, ep)) { + free(pt); + (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC, + "esp_print: can't push buffer on buffer stack"); + } - /* sanity check for pad length */ - if (ep - bp < *(ep - 2)) - goto fail; + /* + * Sanity check for pad length; if it, plus 2 for the pad + * length and next header fields, is bigger than the ciphertext + * length (which is also the plaintext length), it's too big. + * + * XXX - the check can fail if the packet is corrupt *or* if + * it was not decrypted with the correct key, so that the + * "plaintext" is not what was being sent. + */ + padlen = GET_U_1(ep - 2); + if (padlen + 2 > payloadlen) { + nd_print_trunc(ndo); + return; + } - if (padlen) - *padlen = *(ep - 2) + 2; + /* Get the next header */ + nh = GET_U_1(ep - 1); - if (nhdr) - *nhdr = *(ep - 1); + ND_PRINT(": "); - (ndo->ndo_printf)(ndo, ": "); - return advance; -#endif + /* Now dissect the plaintext. */ + ip_demux_print(ndo, pt, payloadlen - (padlen + 2), ver, fragmented, + ttl_hl, nh, bp2); -fail: - return -1; + /* Pop the buffer, freeing it. */ + nd_pop_packet_info(ndo); +#endif } - -/* - * Local Variables: - * c-style: whitesmith - * c-basic-offset: 8 - * End: - */ +#ifdef HAVE_LIBCRYPTO +USES_APPLE_RST +#endif