Passenger: BCrypt.h Source File

00001 /*
00002  * Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
00003  * All rights reserved.
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions
00007  * are met:
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 3. All advertising materials mentioning features or use of this software
00014  *    must display the following acknowledgement:
00015  *      This product includes software developed by Niels Provos.
00016  * 4. The name of the author may not be used to endorse or promote products
00017  *    derived from this software without specific prior written permission.
00018  *
00019  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
00020  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00021  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
00022  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
00023  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
00024  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
00025  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
00026  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
00027  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
00028  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00029  */
00030 
00031 /*
00032  * Modified by <hongli@phusion.nl> on 2009-10-24:
00033  *
00034  *   - Wrapped into C++ namespace.
00035  *   - Changed some types (e.g. u_int8_t to uint8_t as defined in stdint.h)
00036  *     for easier compilation.
00037  *   - Moved some macros to the .c file.
00038  */
00039 
00040 #ifndef _PASSENGER_BCRYPT_H_
00041 #define _PASSENGER_BCRYPT_H_
00042 
00043 #include <stdint.h>
00044 
00045 #define BCRYPT_MAXSALT 16       /* Precomputation is just so nice */
00046 #define BCRYPT_SALT_OUTPUT_SIZE  (7 + (BCRYPT_MAXSALT * 4 + 2) / 3 + 1)
00047 #define BCRYPT_OUTPUT_SIZE 128
00048 
00049 /*
00050  * Given a logarithmic cost parameter, generates a salt for use with bcrypt().
00051  *
00052  * output: the computed salt will be stored here. This buffer must be
00053  *         at least BCRYPT_SALT_OUTPUT_SIZE bytes. The result will be
00054  *         null-terminated.
00055  * log_rounds: the logarithmic cost.
00056  * rseed: a seed of BCRYPT_MAXSALT bytes. Should be obtained from a
00057  *        cryptographically secure random source.
00058  * Returns: output
00059  */
00060 char *bcrypt_gensalt(char *output, unsigned int log_rounds, uint8_t *rseed);
00061 
00062 /*
00063  * Given a secret and a salt, generates a salted hash (which you can then store safely).
00064  *
00065  * output: the computed salted hash will be stored here. This buffer must
00066  *         be at least BCRYPT_OUTPUT_SIZE bytes, and will become null-terminated.
00067  * key: A null-terminated secret.
00068  * salt: The salt, as generated by bcrypt_gensalt().
00069  * Returns: output on success, NULL on error.
00070  */
00071 char *bcrypt(char *output, const char *key, const char *salt);
00072 
00073 #endif /* _PASSENGER_BCRYPT_H_ */