js/scrypt-genpass
Archived
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Copy scryptenc.{c,h} to genpass.{c,h}

Browse source
This commit is contained in:
Chris Oei 2012-09-02 14:44:26 -07:00
parent 84c31465be
commit 324f7a8124
2 changed files with 718 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

606
lib/genpass/genpass.c Normal file
View file

@ -0,0 +1,606 @@
/*-
* 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.
*/
#include "scrypt_platform.h"
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <openssl/aes.h>
#include "crypto_aesctr.h"
#include "crypto_scrypt.h"
#include "memlimit.h"
#include "scryptenc_cpuperf.h"
#include "sha256.h"
#include "sysendian.h"
#include "scryptenc.h"
#define ENCBLOCK 65536
static int pickparams(size_t, double, double,
int *, uint32_t *, uint32_t *);
static int checkparams(size_t, double, double, int, uint32_t, uint32_t);
static int getsalt(uint8_t[32]);
static int
pickparams(size_t maxmem, double maxmemfrac, double maxtime,
int * logN, uint32_t * r, uint32_t * p)
{
size_t memlimit;
double opps;
double opslimit;
double maxN, maxrp;
int rc;
/* Figure out how much memory to use. */
if (memtouse(maxmem, maxmemfrac, &memlimit))
return (1);
/* Figure out how fast the CPU is. */
if ((rc = scryptenc_cpuperf(&opps)) != 0)
return (rc);
opslimit = opps * maxtime;
/* Allow a minimum of 2^15 salsa20/8 cores. */
if (opslimit < 32768)
opslimit = 32768;
/* Fix r = 8 for now. */
*r = 8;
/*
* The memory limit requires that 128Nr <= memlimit, while the CPU
* limit requires that 4Nrp <= opslimit. If opslimit < memlimit/32,
* opslimit imposes the stronger limit on N.
*/
#ifdef DEBUG
fprintf(stderr, "Requiring 128Nr <= %zu, 4Nrp <= %f\n",
memlimit, opslimit);
#endif
if (opslimit < memlimit/32) {
/* Set p = 1 and choose N based on the CPU limit. */
*p = 1;
maxN = opslimit / (*r * 4);
for (*logN = 1; *logN < 63; *logN += 1) {
if ((uint64_t)(1) << *logN > maxN / 2)
break;
}
} else {
/* Set N based on the memory limit. */
maxN = memlimit / (*r * 128);
for (*logN = 1; *logN < 63; *logN += 1) {
if ((uint64_t)(1) << *logN > maxN / 2)
break;
}
/* Choose p based on the CPU limit. */
maxrp = (opslimit / 4) / ((uint64_t)(1) << *logN);
if (maxrp > 0x3fffffff)
maxrp = 0x3fffffff;
*p = (uint32_t)(maxrp) / *r;
}
#ifdef DEBUG
fprintf(stderr, "N = %zu r = %d p = %d\n",
(size_t)(1) << *logN, (int)(*r), (int)(*p));
#endif
/* Success! */
return (0);
}
static int
checkparams(size_t maxmem, double maxmemfrac, double maxtime,
int logN, uint32_t r, uint32_t p)
{
size_t memlimit;
double opps;
double opslimit;
uint64_t N;
int rc;
/* Figure out the maximum amount of memory we can use. */
if (memtouse(maxmem, maxmemfrac, &memlimit))
return (1);
/* Figure out how fast the CPU is. */
if ((rc = scryptenc_cpuperf(&opps)) != 0)
return (rc);
opslimit = opps * maxtime;
/* Sanity-check values. */
if ((logN < 1) || (logN > 63))
return (7);
if ((uint64_t)(r) * (uint64_t)(p) >= 0x40000000)
return (7);
/* Check limits. */
N = (uint64_t)(1) << logN;
if ((memlimit / N) / r < 128)
return (9);
if ((opslimit / N) / (r * p) < 4)
return (10);
/* Success! */
return (0);
}
static int
getsalt(uint8_t salt[32])
{
int fd;
ssize_t lenread;
uint8_t * buf = salt;
size_t buflen = 32;
/* Open /dev/urandom. */
if ((fd = open("/dev/urandom", O_RDONLY)) == -1)
goto err0;
/* Read bytes until we have filled the buffer. */
while (buflen > 0) {
if ((lenread = read(fd, buf, buflen)) == -1)
goto err1;
/* The random device should never EOF. */
if (lenread == 0)
goto err1;
/* We're partly done. */
buf += lenread;
buflen -= lenread;
}
/* Close the device. */
while (close(fd) == -1) {
if (errno != EINTR)
goto err0;
}
/* Success! */
return (0);
err1:
close(fd);
err0:
/* Failure! */
return (4);
}
static int
scryptenc_setup(uint8_t header[96], uint8_t dk[64],
const uint8_t * passwd, size_t passwdlen,
size_t maxmem, double maxmemfrac, double maxtime)
{
uint8_t salt[32];
uint8_t hbuf[32];
int logN;
uint64_t N;
uint32_t r;
uint32_t p;
SHA256_CTX ctx;
uint8_t * key_hmac = &dk[32];
HMAC_SHA256_CTX hctx;
int rc;
/* Pick values for N, r, p. */
if ((rc = pickparams(maxmem, maxmemfrac, maxtime,
&logN, &r, &p)) != 0)
return (rc);
N = (uint64_t)(1) << logN;
/* Get some salt. */
if ((rc = getsalt(salt)) != 0)
return (rc);
/* Generate the derived keys. */
if (crypto_scrypt(passwd, passwdlen, salt, 32, N, r, p, dk, 64))
return (3);
/* Construct the file header. */
memcpy(header, "scrypt", 6);
header[6] = 0;
header[7] = logN;
be32enc(&header[8], r);
be32enc(&header[12], p);
memcpy(&header[16], salt, 32);
/* Add header checksum. */
SHA256_Init(&ctx);
SHA256_Update(&ctx, header, 48);
SHA256_Final(hbuf, &ctx);
memcpy(&header[48], hbuf, 16);
/* Add header signature (used for verifying password). */
HMAC_SHA256_Init(&hctx, key_hmac, 32);
HMAC_SHA256_Update(&hctx, header, 64);
HMAC_SHA256_Final(hbuf, &hctx);
memcpy(&header[64], hbuf, 32);
/* Success! */
return (0);
}
static int
scryptdec_setup(const uint8_t header[96], uint8_t dk[64],
const uint8_t * passwd, size_t passwdlen,
size_t maxmem, double maxmemfrac, double maxtime)
{
uint8_t salt[32];
uint8_t hbuf[32];
int logN;
uint32_t r;
uint32_t p;
uint64_t N;
SHA256_CTX ctx;
uint8_t * key_hmac = &dk[32];
HMAC_SHA256_CTX hctx;
int rc;
/* Parse N, r, p, salt. */
logN = header[7];
r = be32dec(&header[8]);
p = be32dec(&header[12]);
memcpy(salt, &header[16], 32);
/* Verify header checksum. */
SHA256_Init(&ctx);
SHA256_Update(&ctx, header, 48);
SHA256_Final(hbuf, &ctx);
if (memcmp(&header[48], hbuf, 16))
return (7);
/*
* Check whether the provided parameters are valid and whether the
* key derivation function can be computed within the allowed memory
* and CPU time.
*/
if ((rc = checkparams(maxmem, maxmemfrac, maxtime, logN, r, p)) != 0)
return (rc);
/* Compute the derived keys. */
N = (uint64_t)(1) << logN;
if (crypto_scrypt(passwd, passwdlen, salt, 32, N, r, p, dk, 64))
return (3);
/* Check header signature (i.e., verify password). */
HMAC_SHA256_Init(&hctx, key_hmac, 32);
HMAC_SHA256_Update(&hctx, header, 64);
HMAC_SHA256_Final(hbuf, &hctx);
if (memcmp(hbuf, &header[64], 32))
return (11);
/* Success! */
return (0);
}
/**
* 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 * inbuf, size_t inbuflen, uint8_t * outbuf,
const uint8_t * passwd, size_t passwdlen,
size_t maxmem, double maxmemfrac, double maxtime)
{
uint8_t dk[64];
uint8_t hbuf[32];
uint8_t header[96];
uint8_t * key_enc = dk;
uint8_t * key_hmac = &dk[32];
int rc;
HMAC_SHA256_CTX hctx;
AES_KEY key_enc_exp;
struct crypto_aesctr * AES;
/* Generate the header and derived key. */
if ((rc = scryptenc_setup(header, dk, passwd, passwdlen,
maxmem, maxmemfrac, maxtime)) != 0)
return (rc);
/* Copy header into output buffer. */
memcpy(outbuf, header, 96);
/* Encrypt data. */
if (AES_set_encrypt_key(key_enc, 256, &key_enc_exp))
return (5);
if ((AES = crypto_aesctr_init(&key_enc_exp, 0)) == NULL)
return (6);
crypto_aesctr_stream(AES, inbuf, &outbuf[96], inbuflen);
crypto_aesctr_free(AES);
/* Add signature. */
HMAC_SHA256_Init(&hctx, key_hmac, 32);
HMAC_SHA256_Update(&hctx, outbuf, 96 + inbuflen);
HMAC_SHA256_Final(hbuf, &hctx);
memcpy(&outbuf[96 + inbuflen], hbuf, 32);
/* Zero sensitive data. */
memset(dk, 0, 64);
memset(&key_enc_exp, 0, sizeof(AES_KEY));
/* Success! */
return (0);
}
/**
* scryptdec_buf(inbuf, inbuflen, outbuf, outlen, passwd, passwdlen,
* maxmem, maxmemfrac, maxtime):
* Decrypt inbuflen bytes fro 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 * inbuf, size_t inbuflen, uint8_t * outbuf,
size_t * outlen, const uint8_t * passwd, size_t passwdlen,
size_t maxmem, double maxmemfrac, double maxtime)
{
uint8_t hbuf[32];
uint8_t dk[64];
uint8_t * key_enc = dk;
uint8_t * key_hmac = &dk[32];
int rc;
HMAC_SHA256_CTX hctx;
AES_KEY key_enc_exp;
struct crypto_aesctr * AES;
/*
* All versions of the scrypt format will start with "scrypt" and
* have at least 7 bytes of header.
*/
if ((inbuflen < 7) || (memcmp(inbuf, "scrypt", 6) != 0))
return (7);
/* Check the format. */
if (inbuf[6] != 0)
return (8);
/* We must have at least 128 bytes. */
if (inbuflen < 128)
return (7);
/* Parse the header and generate derived keys. */
if ((rc = scryptdec_setup(inbuf, dk, passwd, passwdlen,
maxmem, maxmemfrac, maxtime)) != 0)
return (rc);
/* Decrypt data. */
if (AES_set_encrypt_key(key_enc, 256, &key_enc_exp))
return (5);
if ((AES = crypto_aesctr_init(&key_enc_exp, 0)) == NULL)
return (6);
crypto_aesctr_stream(AES, &inbuf[96], outbuf, inbuflen - 128);
crypto_aesctr_free(AES);
*outlen = inbuflen - 128;
/* Verify signature. */
HMAC_SHA256_Init(&hctx, key_hmac, 32);
HMAC_SHA256_Update(&hctx, inbuf, inbuflen - 32);
HMAC_SHA256_Final(hbuf, &hctx);
if (memcmp(hbuf, &inbuf[inbuflen - 32], 32))
return (7);
/* Zero sensitive data. */
memset(dk, 0, 64);
memset(&key_enc_exp, 0, sizeof(AES_KEY));
/* Success! */
return (0);
}
/**
* 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 * infile, FILE * outfile,
const uint8_t * passwd, size_t passwdlen,
size_t maxmem, double maxmemfrac, double maxtime)
{
uint8_t buf[ENCBLOCK];
uint8_t dk[64];
uint8_t hbuf[32];
uint8_t header[96];
uint8_t * key_enc = dk;
uint8_t * key_hmac = &dk[32];
size_t readlen;
HMAC_SHA256_CTX hctx;
AES_KEY key_enc_exp;
struct crypto_aesctr * AES;
int rc;
/* Generate the header and derived key. */
if ((rc = scryptenc_setup(header, dk, passwd, passwdlen,
maxmem, maxmemfrac, maxtime)) != 0)
return (rc);
/* Hash and write the header. */
HMAC_SHA256_Init(&hctx, key_hmac, 32);
HMAC_SHA256_Update(&hctx, header, 96);
if (fwrite(header, 96, 1, outfile) != 1)
return (12);
/*
* Read blocks of data, encrypt them, and write them out; hash the
* data as it is produced.
*/
if (AES_set_encrypt_key(key_enc, 256, &key_enc_exp))
return (5);
if ((AES = crypto_aesctr_init(&key_enc_exp, 0)) == NULL)
return (6);
do {
if ((readlen = fread(buf, 1, ENCBLOCK, infile)) == 0)
break;
crypto_aesctr_stream(AES, buf, buf, readlen);
HMAC_SHA256_Update(&hctx, buf, readlen);
if (fwrite(buf, 1, readlen, outfile) < readlen)
return (12);
} while (1);
crypto_aesctr_free(AES);
/* Did we exit the loop due to a read error? */
if (ferror(infile))
return (13);
/* Compute the final HMAC and output it. */
HMAC_SHA256_Final(hbuf, &hctx);
if (fwrite(hbuf, 32, 1, outfile) != 1)
return (12);
/* Zero sensitive data. */
memset(dk, 0, 64);
memset(&key_enc_exp, 0, sizeof(AES_KEY));
/* Success! */
return (0);
}
/**
* 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 * infile, FILE * outfile,
const uint8_t * passwd, size_t passwdlen,
size_t maxmem, double maxmemfrac, double maxtime)
{
uint8_t buf[ENCBLOCK + 32];
uint8_t header[96];
uint8_t hbuf[32];
uint8_t dk[64];
uint8_t * key_enc = dk;
uint8_t * key_hmac = &dk[32];
size_t buflen = 0;
size_t readlen;
HMAC_SHA256_CTX hctx;
AES_KEY key_enc_exp;
struct crypto_aesctr * AES;
int rc;
/*
* Read the first 7 bytes of the file; all future version of scrypt
* are guaranteed to have at least 7 bytes of header.
*/
if (fread(header, 7, 1, infile) < 1) {
if (ferror(infile))
return (13);
else
return (7);
}
/* Do we have the right magic? */
if (memcmp(header, "scrypt", 6))
return (7);
if (header[6] != 0)
return (8);
/*
* Read another 89 bytes of the file; version 0 of the srypt file
* format has a 96-byte header.
*/
if (fread(&header[7], 89, 1, infile) < 1) {
if (ferror(infile))
return (13);
else
return (7);
}
/* Parse the header and generate derived keys. */
if ((rc = scryptdec_setup(header, dk, passwd, passwdlen,
maxmem, maxmemfrac, maxtime)) != 0)
return (rc);
/* Start hashing with the header. */
HMAC_SHA256_Init(&hctx, key_hmac, 32);
HMAC_SHA256_Update(&hctx, header, 96);
/*
* We don't know how long the encrypted data block is (we can't know,
* since data can be streamed into 'scrypt enc') so we need to read
* data and decrypt all of it except the final 32 bytes, then check
* if that final 32 bytes is the correct signature.
*/
if (AES_set_encrypt_key(key_enc, 256, &key_enc_exp))
return (5);
if ((AES = crypto_aesctr_init(&key_enc_exp, 0)) == NULL)
return (6);
do {
/* Read data until we have more than 32 bytes of it. */
if ((readlen = fread(&buf[buflen], 1,
ENCBLOCK + 32 - buflen, infile)) == 0)
break;
buflen += readlen;
if (buflen <= 32)
continue;
/*
* Decrypt, hash, and output everything except the last 32
* bytes out of what we have in our buffer.
*/
HMAC_SHA256_Update(&hctx, buf, buflen - 32);
crypto_aesctr_stream(AES, buf, buf, buflen - 32);
if (fwrite(buf, 1, buflen - 32, outfile) < buflen - 32)
return (12);
/* Move the last 32 bytes to the start of the buffer. */
memmove(buf, &buf[buflen - 32], 32);
buflen = 32;
} while (1);
crypto_aesctr_free(AES);
/* Did we exit the loop due to a read error? */
if (ferror(infile))
return (13);
/* Did we read enough data that we *might* have a valid signature? */
if (buflen < 32)
return (7);
/* Verify signature. */
HMAC_SHA256_Final(hbuf, &hctx);
if (memcmp(hbuf, buf, 32))
return (7);
/* Zero sensitive data. */
memset(dk, 0, 64);
memset(&key_enc_exp, 0, sizeof(AES_KEY));
return (0);
}

112
lib/genpass/genpass.h Normal file
View file

@ -0,0 +1,112 @@
/*-
* 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>
/**
* 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_ */