/* $NetBSD: print-ah.c,v 1.4 1996/05/20 00:41:16 fvdl Exp $ */ /* * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that: (1) source code distributions * retain the above copyright notice and this paragraph in its entirety, (2) * distributions including binary code include the above copyright notice and * this paragraph in its entirety in the documentation or other materials * provided with the distribution, and (3) all advertising materials mentioning * features or use of this software display the following acknowledgement: * ``This product includes software developed by the University of California, * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of * the University 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ /* \summary: IPSEC Encapsulating Security Payload (ESP) printer */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <netdissect-stdinc.h> #include <string.h> #include <stdlib.h> /* 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 <openssl/evp.h> #else #undef HAVE_LIBCRYPTO #endif #endif #include "netdissect.h" #include "strtoaddr.h" #include "extract.h" #include "ascii_strcasecmp.h" #include "ip.h" #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 <tab> 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 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(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_ #endif , int *padlen #ifndef HAVE_LIBCRYPTO _U_ #endif ) { register const struct newesp *esp; register const u_char *ep; #ifdef HAVE_LIBCRYPTO const struct ip *ip; struct sa_list *sa = NULL; const struct ip6_hdr *ip6 = NULL; int advance; int len; u_char *secret; int ivlen = 0; 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 #if 0 /* keep secret out of a register */ p = (u_char *)&secret; #endif /* 'ep' points to the end of available data. */ ep = ndo->ndo_snapend; if ((const u_char *)(esp + 1) >= ep) { ND_PRINT((ndo, "[|ESP]")); goto fail; } ND_PRINT((ndo, "ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi))); ND_PRINT((ndo, ",seq=0x%x)", EXTRACT_32BITS(&esp->esp_seq))); ND_PRINT((ndo, ", length %u", length)); #ifndef HAVE_LIBCRYPTO goto fail; #else /* initiailize SAs */ if (ndo->ndo_sa_list_head == NULL) { if (!ndo->ndo_espsecret) goto fail; esp_print_decodesecret(ndo); } if (ndo->ndo_sa_list_head == NULL) goto fail; ip = (const struct ip *)bp2; switch (IP_V(ip)) { case 6: ip6 = (const struct ip6_hdr *)bp2; /* we do not attempt to decrypt jumbograms */ if (!EXTRACT_16BITS(&ip6->ip6_plen)) goto fail; /* 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) { if (sa->spi == EXTRACT_32BITS(&esp->esp_spi) && sa->daddr_version == 6 && UNALIGNED_MEMCMP(&sa->daddr.in6, &ip6->ip6_dst, sizeof(struct in6_addr)) == 0) { break; } } break; 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); /* 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_32BITS(&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 didn't find the specific one, then look for * an unspecified one. */ 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; } /* 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)) goto fail; if (padlen) *padlen = *(ep - 2) + 2; if (nhdr) *nhdr = *(ep - 1); ND_PRINT((ndo, ": ")); return advance; #endif fail: return -1; } #ifdef HAVE_LIBCRYPTO USES_APPLE_RST #endif /* * Local Variables: * c-style: whitesmith * c-basic-offset: 8 * End: */