/* $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. */ #ifndef lint static const char rcsid[] = "@(#) $Header: /tcpdump/master/tcpdump/print-esp.c,v 1.39 2003-05-02 08:43:28 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #ifdef HAVE_LIBCRYPTO #include #include #ifdef HAVE_OPENSSL_RC5_H #include #endif #ifdef HAVE_OPENSSL_CAST_H #include #endif #endif #include #include "ip.h" #include "esp.h" #ifdef INET6 #include "ip6.h" #endif #if defined(__MINGW32__) || defined(__WATCOMC__) extern char *strsep (char **stringp, const char *delim); /* Missing/strsep.c */ #endif #define AVOID_CHURN 1 #include "interface.h" #include "addrtoname.h" #include "extract.h" enum cipher { NONE, DESCBC, BLOWFISH, RC5, CAST128, DES3CBC}; struct esp_algorithm { const char *name; enum cipher algo; int ivlen; int authlen; int replaysize; /* number of bytes, in excess of 4, may be negative */ }; struct esp_algorithm esp_xforms[]={ {"none", NONE, 0, 0, 0}, {"des-cbc", DESCBC, 8, 0, 0}, {"des-cbc-hmac96", DESCBC, 8, 12, 0}, {"blowfish-cbc", BLOWFISH,8, 0, 0}, {"blowfish-cbc-hmac96", BLOWFISH,8, 12, 0}, {"rc5-cbc", RC5, 8, 0, 0}, {"rc5-cbc-hmac96", RC5, 8, 12, 0}, {"cast128-cbc", CAST128, 8, 0, 0}, {"cast128-cbc-hmac96", CAST128, 8, 12, 0}, {"3des-cbc-hmac96", DES3CBC, 8, 12, 0}, {NULL, NONE, 0, 0, 0} }; struct esp_algorithm *null_xf = &esp_xforms[sizeof(esp_xforms)/sizeof(esp_xforms[0]) - 1]; #ifndef HAVE_SOCKADDR_STORAGE #ifdef INET6 struct sockaddr_storage { union { struct sockaddr_in sin; struct sockaddr_in6 sin6; } un; }; #else #define sockaddr_storage sockaddr #endif #endif /* HAVE_SOCKADDR_STORAGE */ struct sa_list { struct sa_list *next; struct sockaddr_storage daddr; u_int32_t spi; struct esp_algorithm *xform; char secret[256]; /* is that big enough for all secrets? */ int secretlen; }; static struct sa_list *sa_list_head=NULL; static struct sa_list *sa_default=NULL; static void esp_print_addsa(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) error("ran out of memory to allocate sa structure"); *nsa = *sa; if(sa_def) { sa_default = nsa; } nsa->next = sa_list_head; sa_list_head = nsa; } static int hexdigit(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 { printf("invalid hex digit %c in espsecret\n", hex); return 0; } } static int hex2byte(char *hexstring) { int byte; byte = (hexdigit(hexstring[0]) << 4) + hexdigit(hexstring[1]); return byte; } /* * decode the form: SPINUM@IP ALGONAME:0xsecret * * special form: file /name * causes us to go read from this file instead. * */ static void esp_print_decode_onesecret(char *line) { struct esp_algorithm *xf; 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; /* memset(&sa1.daddr, 0, sizeof(sa1.daddr)); */ /* sa1.spi = 0; */ sa_def = 1; } else { decode = line; } if(spikey && strcasecmp(spikey, "file")==0) { /* open file and read it */ FILE *secretfile; char fileline[1024]; char *nl; secretfile = fopen(line, FOPEN_READ_TXT); if(secretfile == NULL) { perror(line); exit(3); } while(fgets(fileline, sizeof(fileline)-1, secretfile) != NULL) { /* 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(fileline); } fclose(secretfile); return; } if(spikey) { char *spistr, *foo; u_int32_t spino; struct sockaddr_in *sin; #ifdef INET6 struct sockaddr_in6 *sin6; #endif spistr = strsep(&spikey, "@"); spino = strtoul(spistr, &foo, 0); if(spistr == foo || !spikey) { printf("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 { printf("print_esp: can not decode IP# %s\n", spikey); return; } } if(decode) { char *colon; char espsecret_key[256]; unsigned int len, i; /* skip any blank spaces */ while(isspace((unsigned char)*decode)) decode++; colon = strchr(decode, ':'); if(colon == NULL) { printf("failed to decode espsecret: %s\n", decode); return; } len = colon - decode; xf = esp_xforms; while(xf->name && strncasecmp(decode, xf->name, len)!=0) { xf++; } if(xf->name == NULL) { printf("failed to find cipher algo %s\n", decode); /* set to NULL transform */ return; } sa1.xform = xf; colon++; if(colon[0]=='0' && colon[1]=='x') { /* decode some hex! */ colon+=2; len = strlen(colon) / 2; if(len > 256) { printf("secret is too big: %d\n", len); return; } i = 0; while(colon[0] != '\0' && colon[1]!='\0') { espsecret_key[i]=hex2byte(colon); colon+=2; i++; } memcpy(sa1.secret, espsecret_key, i); sa1.secretlen=i; } else { i = strlen(colon); if(i < sizeof(sa1.secret)) { memcpy(sa1.secret, espsecret_key, i); sa1.secretlen = i; } else { memcpy(sa1.secret, espsecret_key, sizeof(sa1.secret)); sa1.secretlen = sizeof(sa1.secret); } } } esp_print_addsa(&sa1, sa_def); } static void esp_print_decodesecret(void) { char *line; char *p; if(espsecret == NULL) { sa_list_head = NULL; return; } if(sa_list_head != NULL) { return; } p=espsecret; while(espsecret && espsecret[0]!='\0') { /* pick out the first line or first thing until a comma */ if((line = strsep(&espsecret, "\n,"))==NULL) { line=espsecret; espsecret=NULL; } esp_print_decode_onesecret(line); } } int esp_print(register const u_char *bp, register const u_char *bp2, int *nhdr, int *padlen) { register const struct newesp *esp; register const u_char *ep; struct ip *ip; struct sa_list *sa = NULL; int espsecret_keylen; #ifdef INET6 struct ip6_hdr *ip6 = NULL; #endif int advance; int len; char *secret; int ivlen = 0; u_char *ivoff; #ifdef HAVE_LIBCRYPTO u_char *p; #endif esp = (struct newesp *)bp; secret = NULL; advance = 0; #if 0 /* keep secret out of a register */ p = (u_char *)&secret; #endif /* 'ep' points to the end of available data. */ ep = snapend; if ((u_char *)(esp + 1) >= ep) { fputs("[|ESP]", stdout); goto fail; } printf("ESP(spi=0x%08x", EXTRACT_32BITS(&esp->esp_spi)); printf(",seq=0x%x", EXTRACT_32BITS(&esp->esp_seq)); printf(")"); /* if we don't have decryption key, we can't decrypt this packet. */ if(sa_list_head == NULL) { if (!espsecret) { goto fail; } esp_print_decodesecret(); } if(sa_list_head == NULL) { goto fail; } ip = (struct ip *)bp2; switch (IP_V(ip)) { #ifdef INET6 case 6: ip6 = (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 = sa_list_head; sa != NULL; sa = sa->next) { struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&sa->daddr; if (sa->spi == ntohl(esp->esp_spi) && sin6->sin6_family == AF_INET6 && memcmp(&sin6->sin6_addr, &ip6->ip6_dst, sizeof(struct in6_addr)) == 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); /* see if we can find the SA, and if so, decode it */ for (sa = sa_list_head; sa != NULL; sa = sa->next) { struct sockaddr_in *sin = (struct sockaddr_in *)&sa->daddr; if (sa->spi == ntohl(esp->esp_spi) && sin->sin_family == AF_INET && sin->sin_addr.s_addr == ip->ip_dst.s_addr) { break; } } break; default: goto fail; } /* if we didn't find the specific one, then look for * an unspecified one. */ if(sa == NULL) { sa = 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; } ivoff = (u_char *)(esp + 1) + sa->xform->replaysize; ivlen = sa->xform->ivlen; secret = sa->secret; espsecret_keylen = sa->secretlen; switch (sa->xform->algo) { case DESCBC: #ifdef HAVE_LIBCRYPTO { u_char iv[8]; #if OPENSSL_VERSION_NUMBER >= 0x00907000L DES_key_schedule schedule; #else des_key_schedule schedule; #endif 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; } p = ivoff + ivlen; if (espsecret_keylen != 8) goto fail; #if OPENSSL_VERSION_NUMBER >= 0x00908000L DES_set_key_unchecked((const_DES_cblock *)secret, &schedule); DES_cbc_encrypt((const unsigned char *)p, p, (long)(ep - p), &schedule, (DES_cblock *)iv, DES_DECRYPT); #elif OPENSSL_VERSION_NUMBER >= 0x00907000L DES_set_key_unchecked((DES_cblock *)secret, schedule); DES_cbc_encrypt((const unsigned char *)p, p, (long)(ep - p), schedule, (DES_cblock *)iv, DES_DECRYPT); #else des_check_key = 0; des_set_key((void *)secret, schedule); des_cbc_encrypt((void *)p, (void *)p, (long)(ep - p), schedule, (void *)iv, DES_DECRYPT); #endif advance = ivoff - (u_char *)esp + ivlen; break; } #else goto fail; #endif /*HAVE_LIBCRYPTO*/ case BLOWFISH: #ifdef HAVE_LIBCRYPTO { BF_KEY schedule; if (espsecret_keylen < 5 || espsecret_keylen > 56) goto fail; BF_set_key(&schedule, espsecret_keylen, secret); p = ivoff + ivlen; BF_cbc_encrypt(p, p, (long)(ep - p), &schedule, ivoff, BF_DECRYPT); advance = ivoff - (u_char *)esp + ivlen; break; } #else goto fail; #endif /*HAVE_LIBCRYPTO*/ case RC5: #if defined(HAVE_LIBCRYPTO) && defined(HAVE_RC5_H) { RC5_32_KEY schedule; if (espsecret_keylen < 5 || espsecret_keylen > 255) goto fail; RC5_32_set_key(&schedule, espsecret_keylen, 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; if (espsecret_keylen < 5 || espsecret_keylen > 16) goto fail; CAST_set_key(&schedule, espsecret_keylen, 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) { #if OPENSSL_VERSION_NUMBER >= 0x00907000L DES_key_schedule s1, s2, s3; if (espsecret_keylen != 24) goto fail; DES_set_odd_parity((DES_cblock *)secret); DES_set_odd_parity((DES_cblock *)(secret + 8)); DES_set_odd_parity((DES_cblock *)(secret + 16)); #if OPENSSL_VERSION_NUMBER >= 0x00908000L if(DES_set_key_checked((const_DES_cblock *)secret, &s1) != 0) { printf("failed to schedule key 1\n"); } if(DES_set_key_checked((const_DES_cblock *)(secret + 8), &s2)!=0) { printf("failed to schedule key 2\n"); } if(DES_set_key_checked((const_DES_cblock *)(secret + 16), &s3)!=0) { printf("failed to schedule key 3\n"); } #else if(DES_set_key_checked((DES_cblock *)secret, s1) != 0) { printf("failed to schedule key 1\n"); } if(DES_set_key_checked((DES_cblock *)(secret + 8), s2)!=0) { printf("failed to schedule key 2\n"); } if(DES_set_key_checked((DES_cblock *)(secret + 16), s3)!=0) { printf("failed to schedule key 3\n"); } #endif p = ivoff + ivlen; DES_ede3_cbc_encrypt((const unsigned char *)p, p, (long)(ep - p), &s1, &s2, &s3, (DES_cblock *)ivoff, DES_DECRYPT); #else des_key_schedule s1, s2, s3; if (espsecret_keylen != 24) goto fail; des_check_key = 1; des_set_odd_parity((void *)secret); des_set_odd_parity((void *)(secret + 8)); des_set_odd_parity((void *)(secret + 16)); if(des_set_key((void *)secret, s1) != 0) { printf("failed to schedule key 1\n"); } if(des_set_key((void *)(secret + 8), s2)!=0) { printf("failed to schedule key 2\n"); } if(des_set_key((void *)(secret + 16), s3)!=0) { printf("failed to schedule key 3\n"); } p = ivoff + ivlen; des_ede3_cbc_encrypt((void *)p, (void *)p, (long)(ep - p), s1, s2, s3, (void *)ivoff, DES_DECRYPT); #endif advance = ivoff - (u_char *)esp + ivlen; break; } #else goto fail; #endif /*HAVE_LIBCRYPTO*/ case NONE: default: advance = sizeof(struct newesp) + sa->xform->replaysize; break; } ep = ep - sa->xform->authlen; /* sanity check for pad length */ if (ep - bp < *(ep - 2)) goto fail; if (padlen) *padlen = *(ep - 2) + 2; if (nhdr) *nhdr = *(ep - 1); printf(": "); return advance; fail: if (nhdr) *nhdr = -1; return 65536; }