+
+/* Creates fingerprint of the data. If `hash' is NULL SHA1 is used as
+ default hash function. The returned fingerprint must be free's by the
+ caller. */
+
+char *silc_hash_fingerprint(SilcHash hash, const unsigned char *data,
+ SilcUInt32 data_len)
+{
+ SilcHash new_hash = NULL;
+ unsigned char h[32];
+ char *ret;
+
+ if (!hash) {
+ silc_hash_alloc("sha1", &new_hash);
+ hash = new_hash;
+ }
+
+ silc_hash_make(hash, data, data_len, h);
+ ret = silc_fingerprint(h, hash->hash->hash_len);
+
+ if (new_hash != NULL)
+ silc_hash_free(new_hash);
+ return ret;
+}
+
+static const char vo[]= "aeiouy";
+static const char co[]= "bcdfghklmnprstvzx";
+
+/* Creates a babbleprint (Bubble Babble Encoding, developed by Antti
+ Huima (draft-huima-babble-01.txt)), by first computing real fingerprint
+ using `hash' or if NULL, then using SHA1, and then encoding the
+ fingerprint to the babbleprint. */
+
+char *silc_hash_babbleprint(SilcHash hash, const unsigned char *data,
+ SilcUInt32 data_len)
+{
+ SilcHash new_hash = NULL;
+ char *babbleprint;
+ unsigned char hval[32];
+ unsigned int a, b, c, d, e, check;
+ int i, k, out_len;
+
+ if (!hash) {
+ silc_hash_alloc("sha1", &new_hash);
+ hash = new_hash;
+ }
+
+ /* Take fingerprint */
+ silc_hash_make(hash, data, data_len, hval);
+
+ /* Encode babbleprint */
+ out_len = (((hash->hash->hash_len + 1) / 2) + 1) * 6;
+ babbleprint = silc_calloc(out_len, sizeof(*babbleprint));
+ babbleprint[0] = co[16];
+
+ check = 1;
+ for (i = 0, k = 1; i < hash->hash->hash_len - 1; i += 2, k += 6) {
+ a = (((hval[i] >> 6) & 3) + check) % 6;
+ b = (hval[i] >> 2) & 15;
+ c = ((hval[i] & 3) + (check / 6)) % 6;
+ d = (hval[i + 1] >> 4) & 15;
+ e = hval[i + 1] & 15;
+
+ check = ((check * 5) + (hval[i] * 7) + hval[i + 1]) % 36;
+
+ babbleprint[k + 0] = vo[a];
+ babbleprint[k + 1] = co[b];
+ babbleprint[k + 2] = vo[c];
+ babbleprint[k + 3] = co[d];
+ babbleprint[k + 4] = '-';
+ babbleprint[k + 5] = co[e];
+ }
+
+ if ((hash->hash->hash_len % 2) != 0) {
+ a = (((hval[i] >> 6) & 3) + check) % 6;
+ b = (hval[i] >> 2) & 15;
+ c = ((hval[i] & 3) + (check / 6)) % 6;
+ babbleprint[k + 0] = vo[a];
+ babbleprint[k + 1] = co[b];
+ babbleprint[k + 2] = vo[c];
+ } else {
+ a = check % 6;
+ b = 16;
+ c = check / 6;
+ babbleprint[k + 0] = vo[a];
+ babbleprint[k + 1] = co[b];
+ babbleprint[k + 2] = vo[c];
+ }
+ babbleprint[k + 3] = co[16];
+
+ if (new_hash != NULL)
+ silc_hash_free(new_hash);
+ return babbleprint;
+}