+ * Hashing algorithms.
+ *
+ * Example for using hasher_t:
+ * @code
+ * chunk_t data;
+ * chunk_t md5_hash;
+ * u_int8_t sha1_hash[20];
+ *
+ * hasher_t *hasher;
+ *
+ * data.ptr = "string to hash";
+ * data.len = strlen(data.ptr);
+ *
+ * // use MD5, allocate hash
+ * hasher = hasher_create(HASH_MD5);
+ * hasher->allocate_hash(hasher, data, &hash);
+ * hasher->destroy(hasher);
+ *
+ * // use SHA1, hash in buffer
+ * hasher = hasher_create(HASH_SHA1);
+ * hasher->get_hash(hasher, data, &sha1_hash);
+ * hasher->destroy(hasher);
+ * @endcode
+ *
+ *