libcryfs/vendor/scrypt-1.2.0/lib/scryptenc/scryptenc.h
2016-02-10 00:58:03 +01:00

121 lines
4.9 KiB
C

/*-
* Copyright 2009 Colin Percival
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file was originally written by Colin Percival as part of the Tarsnap
* online backup system.
*/
#ifndef _SCRYPTENC_H_
#define _SCRYPTENC_H_
#include <stdint.h>
#include <stdio.h>
/**
* NOTE: This file provides prototypes for routines which encrypt/decrypt data
* using a key derived from a password by using the scrypt key derivation
* function. If you are just trying to "hash" a password for user logins,
* this is not the code you are looking for. You want to use the crypt_scrypt
* function directly.
*/
/**
* The parameters maxmem, maxmemfrac, and maxtime used by all of these
* functions are defined as follows:
* maxmem - maximum number of bytes of storage to use for V array (which is
* by far the largest consumer of memory). If this value is set to 0, no
* maximum will be enforced; any other value less than 1 MiB will be
* treated as 1 MiB.
* maxmemfrac - maximum fraction of available storage to use for the V array,
* where "available storage" is defined as the minimum out of the
* RLIMIT_AS, RLIMIT_DATA. and RLIMIT_RSS resource limits (if any are
* set). If this value is set to 0 or more than 0.5 it will be treated
* as 0.5; and this value will never cause a limit of less than 1 MiB to
* be enforced.
* maxtime - maximum amount of CPU time to spend computing the derived keys,
* in seconds. This limit is only approximately enforced; the CPU
* performance is estimated and parameter limits are chosen accordingly.
* For the encryption functions, the parameters to the scrypt key derivation
* function are chosen to make the key as strong as possible subject to the
* specified limits; for the decryption functions, the parameters used are
* compared to the computed limits and an error is returned if decrypting
* the data would take too much memory or CPU time.
*/
/**
* Return codes from scrypt(enc|dec)_(buf|file):
* 0 success
* 1 getrlimit or sysctl(hw.usermem) failed
* 2 clock_getres or clock_gettime failed
* 3 error computing derived key
* 4 could not read salt from /dev/urandom
* 5 error in OpenSSL
* 6 malloc failed
* 7 data is not a valid scrypt-encrypted block
* 8 unrecognized scrypt format
* 9 decrypting file would take too much memory
* 10 decrypting file would take too long
* 11 password is incorrect
* 12 error writing output file
* 13 error reading input file
*/
/**
* scryptenc_buf(inbuf, inbuflen, outbuf, passwd, passwdlen,
* maxmem, maxmemfrac, maxtime):
* Encrypt inbuflen bytes from inbuf, writing the resulting inbuflen + 128
* bytes to outbuf.
*/
int scryptenc_buf(const uint8_t *, size_t, uint8_t *,
const uint8_t *, size_t, size_t, double, double);
/**
* scryptdec_buf(inbuf, inbuflen, outbuf, outlen, passwd, passwdlen,
* maxmem, maxmemfrac, maxtime):
* Decrypt inbuflen bytes from inbuf, writing the result into outbuf and the
* decrypted data length to outlen. The allocated length of outbuf must
* be at least inbuflen.
*/
int scryptdec_buf(const uint8_t *, size_t, uint8_t *, size_t *,
const uint8_t *, size_t, size_t, double, double);
/**
* scryptenc_file(infile, outfile, passwd, passwdlen,
* maxmem, maxmemfrac, maxtime):
* Read a stream from infile and encrypt it, writing the resulting stream to
* outfile.
*/
int scryptenc_file(FILE *, FILE *, const uint8_t *, size_t,
size_t, double, double);
/**
* scryptdec_file(infile, outfile, passwd, passwdlen,
* maxmem, maxmemfrac, maxtime):
* Read a stream from infile and decrypt it, writing the resulting stream to
* outfile.
*/
int scryptdec_file(FILE *, FILE *, const uint8_t *, size_t,
size_t, double, double);
#endif /* !_SCRYPTENC_H_ */