-Key *key_new(int);
-Key *key_new_private(int);
-void key_free(Key *);
-Key *key_demote(Key *);
-int key_equal(Key *, Key *);
-char *key_fingerprint(Key *, enum fp_type, enum fp_rep);
-u_char *key_fingerprint_raw(Key *, enum fp_type, u_int *);
-char *key_type(Key *);
-int key_write(Key *, FILE *);
-int key_read(Key *, char **);
-u_int key_size(Key *);
+Key *key_new(int);
+Key *key_new_private(int);
+void key_free(Key *);
+Key *key_demote(const Key *);
+int key_equal(const Key *, const Key *);
+char *key_fingerprint(const Key *, enum fp_type, enum fp_rep);
+u_char *key_fingerprint_raw(const Key *, enum fp_type, u_int *);
+const char *key_type(const Key *);
+int key_write(const Key *, FILE *);
+int key_read(Key *, char **);
+u_int key_size(const Key *);