+BIGNUM *auth_rsa_generate_challenge(Key *);
+int auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
+int auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
+
+int auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *);
+int hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
+int user_key_allowed(struct passwd *, Key *);