+#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);
projects / tcpdump / blobdiff