sxt: added import API desc.;

include/sxt/sxtkey.h

@@ -103,6 +103,18 @@ int sxt_key_dup_public(const sxtkey_t *, sxtkey_t **);
 /* will duplicate private key, if key public error will returns */
 int sxt_key_dup_private(const sxtkey_t *, sxtkey_t **);
 
+/* import key API */
+
+/* import a private key,
+ * the most parameters the same as for export
+ */
+int sxt_key_import_priv_file(const char *file, const char *passkey,
+                             int (*ask_passkey)(char *pkbuf, size_t length, int confirm, void *priv),
+                             void *priv, sxtkey_t **ik);
+
+/* import a public key from a given file */
+int sxt_key_import_public_file(const char *file, sxtkey_t **ik);
+
 /* export key API */
 /** this function will pack the private key to sxt key container and
  * write it to the file.