X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/ad7df8bd34fa495cd9066ca138384b5d85b85523..c0af6af3011d4c55bdadf3dd76cd5fc1115c50d0:/print-esp.c diff --git a/print-esp.c b/print-esp.c index 375075a3..e5a490f5 100644 --- a/print-esp.c +++ b/print-esp.c @@ -24,10 +24,10 @@ /* \summary: IPSEC Encapsulating Security Payload (ESP) printer */ #ifdef HAVE_CONFIG_H -#include "config.h" +#include #endif -#include +#include "netdissect-stdinc.h" #include #include @@ -87,8 +87,8 @@ */ struct newesp { - uint32_t esp_spi; /* ESP */ - uint32_t esp_seq; /* Sequence number */ + 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 */ @@ -145,19 +145,55 @@ EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *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 spii[8], + const u_char spir[8], const u_char *buf, const u_char *end) { struct sa_list *sa; const u_char *iv; - int len; + unsigned int len; EVP_CIPHER_CTX *ctx; + unsigned int block_size, buffer_size; + u_char *input_buffer, *output_buffer; /* initiator arg is any non-zero value */ if(initiator) initiator=1; @@ -188,17 +224,59 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo, ctx = EVP_CIPHER_CTX_new(); if (ctx == NULL) return 0; - if (EVP_CipherInit(ctx, sa->evp, sa->secret, NULL, 0) < 0) + if (set_cipher_parameters(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); + set_cipher_parameters(ctx, NULL, NULL, iv, 0); + /* + * Allocate buffers for the encrypted and decrypted data. + * Both buffers' sizes must be a multiple of the cipher block + * size, and the output buffer must be separate from the input + * buffer. + */ + block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx); + buffer_size = len + (block_size - len % block_size); + + /* + * Attempt to allocate the input buffer. + */ + input_buffer = (u_char *)malloc(buffer_size); + if (input_buffer == NULL) { + EVP_CIPHER_CTX_free(ctx); + (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC, + "can't allocate memory for encrypted data buffer"); + } + /* + * Copy the input data to the encrypted data buffer, and pad it + * with zeroes. + */ + memcpy(input_buffer, buf, len); + memset(input_buffer + len, 0, buffer_size - len); + + /* + * Attempt to allocate the output buffer. + */ + output_buffer = (u_char *)malloc(buffer_size); + if (output_buffer == NULL) { + free(input_buffer); + EVP_CIPHER_CTX_free(ctx); + (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC, + "can't allocate memory for decryption buffer"); + } + EVP_Cipher(ctx, output_buffer, input_buffer, 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(input_buffer); + free(output_buffer); + ndo->ndo_packetp = buf; ndo->ndo_snapend = end; return 1; - } USES_APPLE_RST @@ -209,9 +287,11 @@ 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; @@ -232,8 +312,8 @@ 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); } } @@ -259,7 +339,7 @@ int espprint_decode_hex(netdissect_options *ndo, 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; } @@ -344,7 +424,7 @@ espprint_decode_encalgo(netdissect_options *ndo, 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 @@ -465,9 +545,9 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *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; + (*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) { @@ -497,6 +577,10 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line, 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) { @@ -582,19 +666,19 @@ esp_print(netdissect_options *ndo, _U_ #endif , - int *nhdr + u_int *nhdr #ifndef HAVE_LIBCRYPTO _U_ #endif , - int *padlen + u_int *padlen #ifndef HAVE_LIBCRYPTO _U_ #endif ) { - register const struct newesp *esp; - register const u_char *ep; + const struct newesp *esp; + const u_char *ep; #ifdef HAVE_LIBCRYPTO const struct ip *ip; struct sa_list *sa = NULL; @@ -606,8 +690,11 @@ esp_print(netdissect_options *ndo, const u_char *ivoff; const u_char *p; EVP_CIPHER_CTX *ctx; + unsigned int block_size, buffer_size; + u_char *input_buffer, *output_buffer; #endif + ndo->ndo_protocol = "esp"; esp = (const struct newesp *)bp; #ifdef HAVE_LIBCRYPTO @@ -624,12 +711,12 @@ esp_print(netdissect_options *ndo, ep = ndo->ndo_snapend; if ((const u_char *)(esp + 1) >= ep) { - ND_PRINT((ndo, "[|ESP]")); + nd_print_trunc(ndo); 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)); + ND_PRINT("ESP(spi=0x%08x", EXTRACT_BE_U_4(esp->esp_spi)); + ND_PRINT(",seq=0x%x)", EXTRACT_BE_U_4(esp->esp_seq)); + ND_PRINT(", length %u", length); #ifndef HAVE_LIBCRYPTO goto fail; @@ -650,33 +737,33 @@ esp_print(netdissect_options *ndo, case 6: ip6 = (const struct ip6_hdr *)bp2; /* we do not attempt to decrypt jumbograms */ - if (!EXTRACT_16BITS(&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) + EXTRACT_16BITS(&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_32BITS(&esp->esp_spi) && + 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) { + sizeof(nd_ipv6)) == 0) { break; } } break; case 4: /* nexthdr & padding are in the last fragment */ - if (EXTRACT_16BITS(&ip->ip_off) & IP_MF) + if (EXTRACT_BE_U_2(ip->ip_off) & IP_MF) goto fail; - len = EXTRACT_16BITS(&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_32BITS(&esp->esp_spi) && + 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) { + sizeof(nd_ipv4)) == 0) { break; } } @@ -703,7 +790,9 @@ esp_print(netdissect_options *ndo, 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; @@ -711,13 +800,59 @@ esp_print(netdissect_options *ndo, if (sa->evp) { ctx = EVP_CIPHER_CTX_new(); if (ctx != NULL) { - if (EVP_CipherInit(ctx, sa->evp, secret, NULL, 0) < 0) + if (set_cipher_parameters(ctx, sa->evp, secret, NULL, 0) < 0) (*ndo->ndo_warning)(ndo, "espkey init failed"); p = ivoff; - EVP_CipherInit(ctx, NULL, NULL, p, 0); - EVP_Cipher(ctx, p + ivlen, p + ivlen, ep - (p + ivlen)); + set_cipher_parameters(ctx, NULL, NULL, p, 0); + len = ep - (p + ivlen); + + /* + * Allocate buffers for the encrypted and decrypted + * data. Both buffers' sizes must be a multiple of + * the cipher block size, and the output buffer must + * be separate from the input buffer. + */ + block_size = (unsigned int)EVP_CIPHER_CTX_block_size(ctx); + buffer_size = len + (block_size - len % block_size); + + /* + * Attempt to allocate the input buffer. + */ + input_buffer = (u_char *)malloc(buffer_size); + if (input_buffer == NULL) { + EVP_CIPHER_CTX_free(ctx); + (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC, + "esp_print: can't allocate memory for encrypted data buffer"); + } + /* + * Copy the input data to the encrypted data buffer, + * and pad it with zeroes. + */ + memcpy(input_buffer, p + ivlen, len); + memset(input_buffer + len, 0, buffer_size - len); + + /* + * Attempt to allocate the output buffer. + */ + output_buffer = (u_char *)malloc(buffer_size); + if (output_buffer == NULL) { + free(input_buffer); + EVP_CIPHER_CTX_free(ctx); + (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC, + "esp_print: can't allocate memory for decryption buffer"); + } + + EVP_Cipher(ctx, output_buffer, input_buffer, len); + free(input_buffer); 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); @@ -725,16 +860,16 @@ esp_print(netdissect_options *ndo, 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); - ND_PRINT((ndo, ": ")); + ND_PRINT(": "); return advance; #endif @@ -744,10 +879,3 @@ fail: #ifdef HAVE_LIBCRYPTO USES_APPLE_RST #endif - -/* - * Local Variables: - * c-style: whitesmith - * c-basic-offset: 8 - * End: - */