/*
 * The following notice applies to this header file (only):
 *
 * Copyright (c) 2002,2010,2012 Solar Designer <solar at openwall.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted.
 */

#ifndef _CRYPT_FREESEC_H
#define _CRYPT_FREESEC_H

struct _crypt_extended_local {
	unsigned char output[21];
};

struct _crypt_extended_shared {
	uint32_t psbox[8][64];
	uint32_t ip_maskl[16][16], ip_maskr[16][16];
	uint32_t fp_maskl[8][16], fp_maskr[8][16];
	uint32_t key_perm_maskl[8][16], key_perm_maskr[12][16];
	uint32_t comp_maskl0[4][8], comp_maskr0[4][8];
	uint32_t comp_maskl1[4][16], comp_maskr1[4][16];
};

/*
 * _crypt_extended_init() must be called explicitly before first use of
 * _crypt_extended_r().  Strictly speaking, _crypt_extended_init() is not
 * reentrant unless the "shared" struct happens to be private to each call.
 * All it does is initialize some variables inside the "shared" struct to
 * constant values, so it is unlikely that anything would go wrong if this is
 * done multiple times in parallel, but correct behavior in that case is not
 * guaranteed (e.g., things may go wrong if a given CPU architecture can't
 * operate on 32-bit quantities natively, requiring read-modify-write
 * instruction sequences operating on larger quantities and thus affecting
 * nearby array elements).
 *
 * After _crypt_extended_init() has returned, the resulting "shared" struct
 * may in fact be safely shared between different threads' calls to
 * _crypt_extended_r(), which is in fact reentrant (but each concurrent call
 * must use its own instance of the "local" struct).
 *
 * _crypt_extended_r() returns NULL on error.  Although modern standards say
 * that crypt(3) does in fact return NULL on error, many applications do not
 * expect that.  Thus, it is recommended that a crypt(3)-like wrapper function
 * translate these NULL returns into strings guaranteed to be different from
 * the "setting" string, too short for matching a valid password hash, and not
 * containing any characters that would be special for the passwd file format.
 * Specifically, such a wrapper function may return "*0" on error as long as
 * the "setting" string does not start with "*0", or "*1" otherwise.
 */

void _crypt_extended_init(struct _crypt_extended_shared *shared);

char *_crypt_extended_r(const char *key, const char *setting,
    struct _crypt_extended_local *local,
    const struct _crypt_extended_shared *shared);

#endif