+/** \cond used to distinguish between loading of private/public key */
+#define LOAD_PUBLIC_KEY 0
+#define LOAD_PRIVATE_KEY 1
+#define CHALLENGE_SIZE 64
+/** \endcond **/
+
+/* asymetric (public key) crypto */
+
+/** Opaque structure for public and private keys. */
+struct asymmetric_key;
+
+int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
+ unsigned len, unsigned char *outbuf);
+int priv_decrypt(const char *key_file, unsigned char *outbuf,
+ unsigned char *inbuf, int inlen);
+int get_asymmetric_key(const char *key_file, int private,
+ struct asymmetric_key **result);
+void free_asymmetric_key(struct asymmetric_key *key);
+
+/* random numbers */