+/** @brief Perform the authorization hash function
+ * @param challenge Pointer to challange
+ * @param nchallenge Size of challenge
+ * @param password Password
+ *
+ * Computes H(challenge|password) and returns it as a newly allocated hex
+ * string. Currently the hash function is SHA-1, but this may be changed in
+ * future versions; see @ref AUTHHASH.
+ */