+ /*
+ * 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;
+
+ memset(&ctx, 0, sizeof(ctx));
+ if (EVP_CipherInit(&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);
+ EVP_CIPHER_CTX_cleanup(&ctx);
+
+ ndo->ndo_packetp = buf;
+ ndo->ndo_snapend = end;
+
+ return 1;
+
+}
+USES_APPLE_RST
+
+static void esp_print_addsa(netdissect_options *ndo,
+ 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)
+ (*ndo->ndo_error)(ndo, "ran out of memory to allocate sa structure");
+
+ *nsa = *sa;
+
+ if (sa_def)
+ ndo->ndo_sa_default = nsa;
+
+ nsa->next = ndo->ndo_sa_list_head;
+ ndo->ndo_sa_list_head = nsa;
+}
+
+
+static u_int hexdigit(netdissect_options *ndo, 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 {
+ (*ndo->ndo_error)(ndo, "invalid hex digit %c in espsecret\n", hex);
+ return 0;
+ }
+}
+
+static u_int hex2byte(netdissect_options *ndo, char *hexstring)
+{
+ u_int byte;
+
+ byte = (hexdigit(ndo, hexstring[0]) << 4) + hexdigit(ndo, hexstring[1]);
+ return byte;
+}
+
+/*
+ * returns size of binary, 0 on failure.
+ */
+static
+int espprint_decode_hex(netdissect_options *ndo,
+ u_char *binbuf, unsigned int binbuf_len,
+ char *hex)
+{
+ unsigned int len;
+ int i;
+
+ len = strlen(hex) / 2;
+
+ if (len > binbuf_len) {
+ (*ndo->ndo_warning)(ndo, "secret is too big: %d\n", len);
+ return 0;