+/*
+ * Set the snoop callback for this connection.
+ */
+
+void netsec_set_snoop_callback(netsec_context *nsc,
+ netsec_snoop_callback callback, void *context)
+{
+ nsc->ns_snoop_cb = callback;
+ nsc->ns_snoop_context = context;
+}
+
+/*
+ * A base64-decoding snoop callback
+ */
+
+void
+netsec_b64_snoop_decoder(netsec_context *nsc, const char *string, size_t len,
+ void *context)
+{
+ unsigned char *decoded;
+ size_t decodedlen;
+ int offset;
+ NMH_UNUSED(nsc);
+
+ offset = context ? *((int *) context) : 0;
+
+ if (offset > 0) {
+ /*
+ * Output non-base64 data first.
+ */
+ fprintf(stderr, "%.*s", offset, string);
+ string += offset;
+ len -= offset;
+ }
+
+ if (decodeBase64(string, &decoded, &decodedlen, 1, NULL) == OK) {
+ /*
+ * Some mechanisms produce large binary tokens, which aren't really
+ * readable. So let's do a simple heuristic. If the token is greater
+ * than 100 characters _and_ the first 100 bytes are more than 50%
+ * non-ASCII, then don't print the decoded buffer, just the
+ * base64 text.
+ */
+ if (decodedlen > 100 && !checkascii(decoded, 100)) {
+ fprintf(stderr, "%.*s\n", (int) len, string);
+ } else {
+ char *hexified;
+ hexify(decoded, decodedlen, &hexified);
+ fprintf(stderr, "b64<%s>\n", hexified);
+ free(hexified);
+ }
+ free(decoded);
+ } else {
+ fprintf(stderr, "%.*s\n", (int) len, string);
+ }
+}
+
+/*
+ * If the ASCII content is > 50%, return 1
+ */
+
+static int
+checkascii(const unsigned char *bytes, size_t len)
+{
+ size_t count = 0, half = len / 2;
+
+ while (len-- > 0) {
+ if (isascii(*bytes) && isprint(*bytes) && ++count > half)
+ return 1;
+ bytes++;
+ /* No chance by this point */
+ if (count + len < half)
+ return 0;
+ }
+
+ return 0;
+}
+
projects / nmh / blobdiff