diff options
Diffstat (limited to 'print-esp.c')
| -rw-r--r-- | print-esp.c | 91 |
1 files changed, 67 insertions, 24 deletions
diff --git a/print-esp.c b/print-esp.c index d12b97d..6fabff1 100644 --- a/print-esp.c +++ b/print-esp.c @@ -191,8 +191,8 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo, const u_char *iv; unsigned int len; EVP_CIPHER_CTX *ctx; - unsigned int block_size, output_buffer_size; - u_char *output_buffer; + unsigned int block_size, buffer_size; + u_char *input_buffer, *output_buffer; /* initiator arg is any non-zero value */ if(initiator) initiator=1; @@ -227,19 +227,39 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo, (*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. + * 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); - output_buffer_size = len + (block_size - len % block_size); - output_buffer = (u_char *)malloc(output_buffer_size); + 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, "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) { - (*ndo->ndo_warning)(ndo, "can't allocate memory for decryption buffer"); + free(input_buffer); EVP_CIPHER_CTX_free(ctx); - return 0; + (*ndo->ndo_error)(ndo, "can't allocate memory for decryption buffer"); } - EVP_Cipher(ctx, output_buffer, buf, len); + EVP_Cipher(ctx, output_buffer, input_buffer, len); EVP_CIPHER_CTX_free(ctx); /* @@ -247,6 +267,7 @@ int esp_print_decrypt_buffer_by_ikev2(netdissect_options *ndo, * but changing this would require a more complicated fix. */ memcpy(buf, output_buffer, len); + free(input_buffer); free(output_buffer); ndo->ndo_packetp = buf; @@ -287,7 +308,6 @@ static u_int hexdigit(netdissect_options *ndo, char hex) return (hex - 'a' + 10); else { (*ndo->ndo_error)(ndo, "invalid hex digit %c in espsecret\n", hex); - return 0; } } @@ -398,7 +418,7 @@ 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 @@ -521,7 +541,6 @@ static void esp_print_decode_onesecret(netdissect_options *ndo, char *line, 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) { @@ -551,6 +570,10 @@ 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) { @@ -660,8 +683,8 @@ esp_print(netdissect_options *ndo, const u_char *ivoff; const u_char *p; EVP_CIPHER_CTX *ctx; - unsigned int block_size, output_buffer_size; - u_char *output_buffer; + unsigned int block_size, buffer_size; + u_char *input_buffer, *output_buffer; #endif esp = (const struct newesp *)bp; @@ -777,21 +800,41 @@ esp_print(netdissect_options *ndo, 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. + * 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); - output_buffer_size = len + (block_size - len % block_size); - output_buffer = (u_char *)malloc(output_buffer_size); + 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, "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) { - (*ndo->ndo_warning)(ndo, "can't allocate memory for decryption buffer"); + free(input_buffer); EVP_CIPHER_CTX_free(ctx); - return -1; + (*ndo->ndo_error)(ndo, "can't allocate memory for decryption buffer"); } - EVP_Cipher(ctx, output_buffer, p + ivlen, len); + 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 |