}
#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 allocate a new buffer containing the decrypted data.
* It returns 1 on success and 0 on failure.
const u_char *iv;
const u_char *ct;
unsigned int ctlen;
- int len;
- EVP_CIPHER_CTX *ctx;
- unsigned int block_size;
u_char *pt;
- u_int ptlen;
/* initiator arg is any non-zero value */
if(initiator) initiator=1;
if(end <= ct) return 0;
- ctx = EVP_CIPHER_CTX_new();
- if (ctx == NULL)
- return 0;
- if (set_cipher_parameters(ctx, sa->evp, sa->secret, NULL) < 0) {
- EVP_CIPHER_CTX_free(ctx);
- (*ndo->ndo_warning)(ndo, "espkey init failed");
- return 0;
- }
- if (set_cipher_parameters(ctx, NULL, NULL, iv) < 0) {
- EVP_CIPHER_CTX_free(ctx);
- (*ndo->ndo_warning)(ndo, "IV init failed");
- return 0;
- }
-
- /*
- * At least as I read RFC 5996 section 3.14, 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, "ciphertext size %u is not a multiple of the cipher block size %u",
- ctlen, block_size);
- return 0;
- }
-
- /*
- * 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,
- "can't allocate memory for decryption buffer");
- }
-
- /*
- * 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, "EVP_CIPHER_CTX_set_padding failed");
+ pt = do_decrypt(ndo, "esp_print_decrypt_buffer_by_ikev2", sa, iv,
+ ct, ctlen);
+ if (pt == NULL)
return 0;
- }
- if (!EVP_DecryptUpdate(ctx, pt, &len, ct, ctlen)) {
- free(pt);
- EVP_CIPHER_CTX_free(ctx);
- (*ndo->ndo_warning)(ndo, "EVP_DecryptUpdate failed");
- return 0;
- }
- EVP_CIPHER_CTX_free(ctx);
/*
* Switch to the output buffer for dissection, and save it
const struct ip6_hdr *ip6 = NULL;
const u_char *iv;
u_int ivlen;
+ u_int payloadlen;
const u_char *ct;
- u_int ctlen;
- int len;
- EVP_CIPHER_CTX *ctx;
- unsigned int block_size;
u_char *pt;
- u_int ptlen;
u_int padlen;
u_int nh;
#endif
* the beginning of the authentication data/integrity check
* value, i.e. right past the end of the ciphertext;
*/
- ctlen = ep - ct;
+ payloadlen = ep - ct;
if (sa->evp == NULL)
return;
return;
}
- 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,
- "esp_print: can't allocate memory for cipher context");
- }
-
- if (set_cipher_parameters(ctx, sa->evp, sa->secret, NULL) < 0) {
- EVP_CIPHER_CTX_free(ctx);
- (*ndo->ndo_warning)(ndo, "espkey init failed");
- return;
- }
-
- if (set_cipher_parameters(ctx, NULL, NULL, iv) < 0) {
- EVP_CIPHER_CTX_free(ctx);
- (*ndo->ndo_warning)(ndo, "IV init failed");
+ pt = do_decrypt(ndo, "esp_print", sa, iv, ct, payloadlen);
+ if (pt == NULL)
return;
- }
-
- /*
- * At least as I read 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, "ciphertext size %u is not a multiple of the cipher block size %u",
- ctlen, block_size);
- return;
- }
-
- /*
- * 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,
- "esp_print: can't allocate memory for decryption buffer");
- }
-
- /*
- * 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, "EVP_CIPHER_CTX_set_padding failed");
- return;
- }
- if (!EVP_DecryptUpdate(ctx, pt, &len, ct, ctlen)) {
- free(pt);
- EVP_CIPHER_CTX_free(ctx);
- (*ndo->ndo_warning)(ndo, "EVP_DecryptUpdate failed");
- return;
- }
- EVP_CIPHER_CTX_free(ctx);
/*
* Switch to the output buffer for dissection, and
* save it on the buffer stack so it can be freed.
*/
- ep = pt + ptlen;
+ ep = pt + payloadlen;
if (!nd_push_buffer(ndo, pt, pt, ep)) {
free(pt);
(*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
* "plaintext" is not what was being sent.
*/
padlen = GET_U_1(ep - 2);
- if (padlen + 2 > ptlen) {
+ if (padlen + 2 > payloadlen) {
nd_print_trunc(ndo);
return;
}
ND_PRINT(": ");
/* Now dissect the plaintext. */
- ip_print_demux(ndo, pt, ptlen - (padlen + 2), ver, fragmented,
+ ip_print_demux(ndo, pt, payloadlen - (padlen + 2), ver, fragmented,
ttl_hl, nh, bp2);
/* Pop the buffer, freeing it. */
projects / tcpdump / commitdiff
