-int auth_set_password(const char *, const char *);
-int auth_get_password(const char *, char *);
-int auth_check_password(const char *, const char *);
+#include <stdint.h>
+
+#define TOKEN_SIZE 16
+#define MAX_PASSWORD_LENGTH 64
+#define SCRYPT_SALT_SIZE 8
+#define SCRYPT_OUTPUT_SIZE 32
+#define SCRYPT_N 1<<14
+#define SCRYPT_r 8
+#define SCRYPT_p 1
+
+int auth_set_password(const char *username, const char *password);
+int auth_get_password_version(const char *username);
+int auth_get_password(const char *username, char *password);
+int auth_get_salt(const char *username, uint8_t *salt);
+int auth_check_password(const char *username, const char *password);