freebsd-src/lib/libcrypt/crypt-sha512.c
2011-05-05 01:09:42 +00:00

501 lines
16 KiB
C

/*
* Copyright (c) 2011 The FreeBSD Project. 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.
*/
/* Based on:
* SHA512-based Unix crypt implementation. Released into the Public Domain by
* Ulrich Drepper <drepper@redhat.com>. */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/endian.h>
#include <sys/param.h>
#include <errno.h>
#include <limits.h>
#include <sha512.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "crypt.h"
/* Define our magic string to mark salt for SHA512 "encryption" replacement. */
static const char sha512_salt_prefix[] = "$6$";
/* Prefix for optional rounds specification. */
static const char sha512_rounds_prefix[] = "rounds=";
/* Maximum salt string length. */
#define SALT_LEN_MAX 16
/* Default number of rounds if not explicitly specified. */
#define ROUNDS_DEFAULT 5000
/* Minimum number of rounds. */
#define ROUNDS_MIN 1000
/* Maximum number of rounds. */
#define ROUNDS_MAX 999999999
static char *
crypt_sha512_r(const char *key, const char *salt, char *buffer, int buflen)
{
u_long srounds;
int n;
uint8_t alt_result[64], temp_result[64];
SHA512_CTX ctx, alt_ctx;
size_t salt_len, key_len, cnt, rounds;
char *cp, *copied_key, *copied_salt, *p_bytes, *s_bytes, *endp;
const char *num;
bool rounds_custom;
copied_key = NULL;
copied_salt = NULL;
/* Default number of rounds. */
rounds = ROUNDS_DEFAULT;
rounds_custom = false;
/* Find beginning of salt string. The prefix should normally always
* be present. Just in case it is not. */
if (strncmp(sha512_salt_prefix, salt, sizeof(sha512_salt_prefix) - 1) == 0)
/* Skip salt prefix. */
salt += sizeof(sha512_salt_prefix) - 1;
if (strncmp(salt, sha512_rounds_prefix, sizeof(sha512_rounds_prefix) - 1)
== 0) {
num = salt + sizeof(sha512_rounds_prefix) - 1;
srounds = strtoul(num, &endp, 10);
if (*endp == '$') {
salt = endp + 1;
rounds = MAX(ROUNDS_MIN, MIN(srounds, ROUNDS_MAX));
rounds_custom = true;
}
}
salt_len = MIN(strcspn(salt, "$"), SALT_LEN_MAX);
key_len = strlen(key);
/* Prepare for the real work. */
SHA512_Init(&ctx);
/* Add the key string. */
SHA512_Update(&ctx, key, key_len);
/* The last part is the salt string. This must be at most 8
* characters and it ends at the first `$' character (for
* compatibility with existing implementations). */
SHA512_Update(&ctx, salt, salt_len);
/* Compute alternate SHA512 sum with input KEY, SALT, and KEY. The
* final result will be added to the first context. */
SHA512_Init(&alt_ctx);
/* Add key. */
SHA512_Update(&alt_ctx, key, key_len);
/* Add salt. */
SHA512_Update(&alt_ctx, salt, salt_len);
/* Add key again. */
SHA512_Update(&alt_ctx, key, key_len);
/* Now get result of this (64 bytes) and add it to the other context. */
SHA512_Final(alt_result, &alt_ctx);
/* Add for any character in the key one byte of the alternate sum. */
for (cnt = key_len; cnt > 64; cnt -= 64)
SHA512_Update(&ctx, alt_result, 64);
SHA512_Update(&ctx, alt_result, cnt);
/* Take the binary representation of the length of the key and for
* every 1 add the alternate sum, for every 0 the key. */
for (cnt = key_len; cnt > 0; cnt >>= 1)
if ((cnt & 1) != 0)
SHA512_Update(&ctx, alt_result, 64);
else
SHA512_Update(&ctx, key, key_len);
/* Create intermediate result. */
SHA512_Final(alt_result, &ctx);
/* Start computation of P byte sequence. */
SHA512_Init(&alt_ctx);
/* For every character in the password add the entire password. */
for (cnt = 0; cnt < key_len; ++cnt)
SHA512_Update(&alt_ctx, key, key_len);
/* Finish the digest. */
SHA512_Final(temp_result, &alt_ctx);
/* Create byte sequence P. */
cp = p_bytes = alloca(key_len);
for (cnt = key_len; cnt >= 64; cnt -= 64) {
memcpy(cp, temp_result, 64);
cp += 64;
}
memcpy(cp, temp_result, cnt);
/* Start computation of S byte sequence. */
SHA512_Init(&alt_ctx);
/* For every character in the password add the entire password. */
for (cnt = 0; cnt < 16 + alt_result[0]; ++cnt)
SHA512_Update(&alt_ctx, salt, salt_len);
/* Finish the digest. */
SHA512_Final(temp_result, &alt_ctx);
/* Create byte sequence S. */
cp = s_bytes = alloca(salt_len);
for (cnt = salt_len; cnt >= 64; cnt -= 64) {
memcpy(cp, temp_result, 64);
cp += 64;
}
memcpy(cp, temp_result, cnt);
/* Repeatedly run the collected hash value through SHA512 to burn CPU
* cycles. */
for (cnt = 0; cnt < rounds; ++cnt) {
/* New context. */
SHA512_Init(&ctx);
/* Add key or last result. */
if ((cnt & 1) != 0)
SHA512_Update(&ctx, p_bytes, key_len);
else
SHA512_Update(&ctx, alt_result, 64);
/* Add salt for numbers not divisible by 3. */
if (cnt % 3 != 0)
SHA512_Update(&ctx, s_bytes, salt_len);
/* Add key for numbers not divisible by 7. */
if (cnt % 7 != 0)
SHA512_Update(&ctx, p_bytes, key_len);
/* Add key or last result. */
if ((cnt & 1) != 0)
SHA512_Update(&ctx, alt_result, 64);
else
SHA512_Update(&ctx, p_bytes, key_len);
/* Create intermediate result. */
SHA512_Final(alt_result, &ctx);
}
/* Now we can construct the result string. It consists of three
* parts. */
cp = stpncpy(buffer, sha512_salt_prefix, MAX(0, buflen));
buflen -= sizeof(sha512_salt_prefix) - 1;
if (rounds_custom) {
n = snprintf(cp, MAX(0, buflen), "%s%zu$",
sha512_rounds_prefix, rounds);
cp += n;
buflen -= n;
}
cp = stpncpy(cp, salt, MIN((size_t)MAX(0, buflen), salt_len));
buflen -= MIN((size_t)MAX(0, buflen), salt_len);
if (buflen > 0) {
*cp++ = '$';
--buflen;
}
b64_from_24bit(alt_result[0], alt_result[21], alt_result[42], 4, &buflen, &cp);
b64_from_24bit(alt_result[22], alt_result[43], alt_result[1], 4, &buflen, &cp);
b64_from_24bit(alt_result[44], alt_result[2], alt_result[23], 4, &buflen, &cp);
b64_from_24bit(alt_result[3], alt_result[24], alt_result[45], 4, &buflen, &cp);
b64_from_24bit(alt_result[25], alt_result[46], alt_result[4], 4, &buflen, &cp);
b64_from_24bit(alt_result[47], alt_result[5], alt_result[26], 4, &buflen, &cp);
b64_from_24bit(alt_result[6], alt_result[27], alt_result[48], 4, &buflen, &cp);
b64_from_24bit(alt_result[28], alt_result[49], alt_result[7], 4, &buflen, &cp);
b64_from_24bit(alt_result[50], alt_result[8], alt_result[29], 4, &buflen, &cp);
b64_from_24bit(alt_result[9], alt_result[30], alt_result[51], 4, &buflen, &cp);
b64_from_24bit(alt_result[31], alt_result[52], alt_result[10], 4, &buflen, &cp);
b64_from_24bit(alt_result[53], alt_result[11], alt_result[32], 4, &buflen, &cp);
b64_from_24bit(alt_result[12], alt_result[33], alt_result[54], 4, &buflen, &cp);
b64_from_24bit(alt_result[34], alt_result[55], alt_result[13], 4, &buflen, &cp);
b64_from_24bit(alt_result[56], alt_result[14], alt_result[35], 4, &buflen, &cp);
b64_from_24bit(alt_result[15], alt_result[36], alt_result[57], 4, &buflen, &cp);
b64_from_24bit(alt_result[37], alt_result[58], alt_result[16], 4, &buflen, &cp);
b64_from_24bit(alt_result[59], alt_result[17], alt_result[38], 4, &buflen, &cp);
b64_from_24bit(alt_result[18], alt_result[39], alt_result[60], 4, &buflen, &cp);
b64_from_24bit(alt_result[40], alt_result[61], alt_result[19], 4, &buflen, &cp);
b64_from_24bit(alt_result[62], alt_result[20], alt_result[41], 4, &buflen, &cp);
b64_from_24bit(0, 0, alt_result[63], 2, &buflen, &cp);
if (buflen <= 0) {
errno = ERANGE;
buffer = NULL;
}
else
*cp = '\0'; /* Terminate the string. */
/* Clear the buffer for the intermediate result so that people
* attaching to processes or reading core dumps cannot get any
* information. We do it in this way to clear correct_words[] inside
* the SHA512 implementation as well. */
SHA512_Init(&ctx);
SHA512_Final(alt_result, &ctx);
memset(temp_result, '\0', sizeof(temp_result));
memset(p_bytes, '\0', key_len);
memset(s_bytes, '\0', salt_len);
memset(&ctx, '\0', sizeof(ctx));
memset(&alt_ctx, '\0', sizeof(alt_ctx));
if (copied_key != NULL)
memset(copied_key, '\0', key_len);
if (copied_salt != NULL)
memset(copied_salt, '\0', salt_len);
return buffer;
}
/* This entry point is equivalent to crypt(3). */
char *
crypt_sha512(const char *key, const char *salt)
{
/* We don't want to have an arbitrary limit in the size of the
* password. We can compute an upper bound for the size of the
* result in advance and so we can prepare the buffer we pass to
* `crypt_sha512_r'. */
static char *buffer;
static int buflen;
int needed;
char *new_buffer;
needed = (sizeof(sha512_salt_prefix) - 1
+ sizeof(sha512_rounds_prefix) + 9 + 1
+ strlen(salt) + 1 + 86 + 1);
if (buflen < needed) {
new_buffer = (char *)realloc(buffer, needed);
if (new_buffer == NULL)
return NULL;
buffer = new_buffer;
buflen = needed;
}
return crypt_sha512_r(key, salt, buffer, buflen);
}
#ifdef TEST
static const struct {
const char *input;
const char result[64];
} tests[] =
{
/* Test vectors from FIPS 180-2: appendix C.1. */
{
"abc",
"\xdd\xaf\x35\xa1\x93\x61\x7a\xba\xcc\x41\x73\x49\xae\x20\x41\x31"
"\x12\xe6\xfa\x4e\x89\xa9\x7e\xa2\x0a\x9e\xee\xe6\x4b\x55\xd3\x9a"
"\x21\x92\x99\x2a\x27\x4f\xc1\xa8\x36\xba\x3c\x23\xa3\xfe\xeb\xbd"
"\x45\x4d\x44\x23\x64\x3c\xe8\x0e\x2a\x9a\xc9\x4f\xa5\x4c\xa4\x9f"
},
/* Test vectors from FIPS 180-2: appendix C.2. */
{
"abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmn"
"hijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu",
"\x8e\x95\x9b\x75\xda\xe3\x13\xda\x8c\xf4\xf7\x28\x14\xfc\x14\x3f"
"\x8f\x77\x79\xc6\xeb\x9f\x7f\xa1\x72\x99\xae\xad\xb6\x88\x90\x18"
"\x50\x1d\x28\x9e\x49\x00\xf7\xe4\x33\x1b\x99\xde\xc4\xb5\x43\x3a"
"\xc7\xd3\x29\xee\xb6\xdd\x26\x54\x5e\x96\xe5\x5b\x87\x4b\xe9\x09"
},
/* Test vectors from the NESSIE project. */
{
"",
"\xcf\x83\xe1\x35\x7e\xef\xb8\xbd\xf1\x54\x28\x50\xd6\x6d\x80\x07"
"\xd6\x20\xe4\x05\x0b\x57\x15\xdc\x83\xf4\xa9\x21\xd3\x6c\xe9\xce"
"\x47\xd0\xd1\x3c\x5d\x85\xf2\xb0\xff\x83\x18\xd2\x87\x7e\xec\x2f"
"\x63\xb9\x31\xbd\x47\x41\x7a\x81\xa5\x38\x32\x7a\xf9\x27\xda\x3e"
},
{
"a",
"\x1f\x40\xfc\x92\xda\x24\x16\x94\x75\x09\x79\xee\x6c\xf5\x82\xf2"
"\xd5\xd7\xd2\x8e\x18\x33\x5d\xe0\x5a\xbc\x54\xd0\x56\x0e\x0f\x53"
"\x02\x86\x0c\x65\x2b\xf0\x8d\x56\x02\x52\xaa\x5e\x74\x21\x05\x46"
"\xf3\x69\xfb\xbb\xce\x8c\x12\xcf\xc7\x95\x7b\x26\x52\xfe\x9a\x75"
},
{
"message digest",
"\x10\x7d\xbf\x38\x9d\x9e\x9f\x71\xa3\xa9\x5f\x6c\x05\x5b\x92\x51"
"\xbc\x52\x68\xc2\xbe\x16\xd6\xc1\x34\x92\xea\x45\xb0\x19\x9f\x33"
"\x09\xe1\x64\x55\xab\x1e\x96\x11\x8e\x8a\x90\x5d\x55\x97\xb7\x20"
"\x38\xdd\xb3\x72\xa8\x98\x26\x04\x6d\xe6\x66\x87\xbb\x42\x0e\x7c"
},
{
"abcdefghijklmnopqrstuvwxyz",
"\x4d\xbf\xf8\x6c\xc2\xca\x1b\xae\x1e\x16\x46\x8a\x05\xcb\x98\x81"
"\xc9\x7f\x17\x53\xbc\xe3\x61\x90\x34\x89\x8f\xaa\x1a\xab\xe4\x29"
"\x95\x5a\x1b\xf8\xec\x48\x3d\x74\x21\xfe\x3c\x16\x46\x61\x3a\x59"
"\xed\x54\x41\xfb\x0f\x32\x13\x89\xf7\x7f\x48\xa8\x79\xc7\xb1\xf1"
},
{
"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
"\x20\x4a\x8f\xc6\xdd\xa8\x2f\x0a\x0c\xed\x7b\xeb\x8e\x08\xa4\x16"
"\x57\xc1\x6e\xf4\x68\xb2\x28\xa8\x27\x9b\xe3\x31\xa7\x03\xc3\x35"
"\x96\xfd\x15\xc1\x3b\x1b\x07\xf9\xaa\x1d\x3b\xea\x57\x78\x9c\xa0"
"\x31\xad\x85\xc7\xa7\x1d\xd7\x03\x54\xec\x63\x12\x38\xca\x34\x45"
},
{
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
"\x1e\x07\xbe\x23\xc2\x6a\x86\xea\x37\xea\x81\x0c\x8e\xc7\x80\x93"
"\x52\x51\x5a\x97\x0e\x92\x53\xc2\x6f\x53\x6c\xfc\x7a\x99\x96\xc4"
"\x5c\x83\x70\x58\x3e\x0a\x78\xfa\x4a\x90\x04\x1d\x71\xa4\xce\xab"
"\x74\x23\xf1\x9c\x71\xb9\xd5\xa3\xe0\x12\x49\xf0\xbe\xbd\x58\x94"
},
{
"123456789012345678901234567890123456789012345678901234567890"
"12345678901234567890",
"\x72\xec\x1e\xf1\x12\x4a\x45\xb0\x47\xe8\xb7\xc7\x5a\x93\x21\x95"
"\x13\x5b\xb6\x1d\xe2\x4e\xc0\xd1\x91\x40\x42\x24\x6e\x0a\xec\x3a"
"\x23\x54\xe0\x93\xd7\x6f\x30\x48\xb4\x56\x76\x43\x46\x90\x0c\xb1"
"\x30\xd2\xa4\xfd\x5d\xd1\x6a\xbb\x5e\x30\xbc\xb8\x50\xde\xe8\x43"
}
};
#define ntests (sizeof (tests) / sizeof (tests[0]))
static const struct {
const char *salt;
const char *input;
const char *expected;
} tests2[] =
{
{
"$6$saltstring", "Hello world!",
"$6$saltstring$svn8UoSVapNtMuq1ukKS4tPQd8iKwSMHWjl/O817G3uBnIFNjnQJu"
"esI68u4OTLiBFdcbYEdFCoEOfaS35inz1"
},
{
"$6$rounds=10000$saltstringsaltstring", "Hello world!",
"$6$rounds=10000$saltstringsaltst$OW1/O6BYHV6BcXZu8QVeXbDWra3Oeqh0sb"
"HbbMCVNSnCM/UrjmM0Dp8vOuZeHBy/YTBmSK6H9qs/y3RnOaw5v."
},
{
"$6$rounds=5000$toolongsaltstring", "This is just a test",
"$6$rounds=5000$toolongsaltstrin$lQ8jolhgVRVhY4b5pZKaysCLi0QBxGoNeKQ"
"zQ3glMhwllF7oGDZxUhx1yxdYcz/e1JSbq3y6JMxxl8audkUEm0"
},
{
"$6$rounds=1400$anotherlongsaltstring",
"a very much longer text to encrypt. This one even stretches over more"
"than one line.",
"$6$rounds=1400$anotherlongsalts$POfYwTEok97VWcjxIiSOjiykti.o/pQs.wP"
"vMxQ6Fm7I6IoYN3CmLs66x9t0oSwbtEW7o7UmJEiDwGqd8p4ur1"
},
{
"$6$rounds=77777$short",
"we have a short salt string but not a short password",
"$6$rounds=77777$short$WuQyW2YR.hBNpjjRhpYD/ifIw05xdfeEyQoMxIXbkvr0g"
"ge1a1x3yRULJ5CCaUeOxFmtlcGZelFl5CxtgfiAc0"
},
{
"$6$rounds=123456$asaltof16chars..", "a short string",
"$6$rounds=123456$asaltof16chars..$BtCwjqMJGx5hrJhZywWvt0RLE8uZ4oPwc"
"elCjmw2kSYu.Ec6ycULevoBK25fs2xXgMNrCzIMVcgEJAstJeonj1"
},
{
"$6$rounds=10$roundstoolow", "the minimum number is still observed",
"$6$rounds=1000$roundstoolow$kUMsbe306n21p9R.FRkW3IGn.S9NPN0x50YhH1x"
"hLsPuWGsUSklZt58jaTfF4ZEQpyUNGc0dqbpBYYBaHHrsX."
},
};
#define ntests2 (sizeof (tests2) / sizeof (tests2[0]))
int
main(void)
{
SHA512_CTX ctx;
uint8_t sum[64];
int result = 0;
int i, cnt;
for (cnt = 0; cnt < (int)ntests; ++cnt) {
SHA512_Init(&ctx);
SHA512_Update(&ctx, tests[cnt].input, strlen(tests[cnt].input));
SHA512_Final(sum, &ctx);
if (memcmp(tests[cnt].result, sum, 64) != 0) {
printf("test %d run %d failed\n", cnt, 1);
result = 1;
}
SHA512_Init(&ctx);
for (i = 0; tests[cnt].input[i] != '\0'; ++i)
SHA512_Update(&ctx, &tests[cnt].input[i], 1);
SHA512_Final(sum, &ctx);
if (memcmp(tests[cnt].result, sum, 64) != 0) {
printf("test %d run %d failed\n", cnt, 2);
result = 1;
}
}
/* Test vector from FIPS 180-2: appendix C.3. */
char buf[1000];
memset(buf, 'a', sizeof(buf));
SHA512_Init(&ctx);
for (i = 0; i < 1000; ++i)
SHA512_Update(&ctx, buf, sizeof(buf));
SHA512_Final(sum, &ctx);
static const char expected[64] =
"\xe7\x18\x48\x3d\x0c\xe7\x69\x64\x4e\x2e\x42\xc7\xbc\x15\xb4\x63"
"\x8e\x1f\x98\xb1\x3b\x20\x44\x28\x56\x32\xa8\x03\xaf\xa9\x73\xeb"
"\xde\x0f\xf2\x44\x87\x7e\xa6\x0a\x4c\xb0\x43\x2c\xe5\x77\xc3\x1b"
"\xeb\x00\x9c\x5c\x2c\x49\xaa\x2e\x4e\xad\xb2\x17\xad\x8c\xc0\x9b";
if (memcmp(expected, sum, 64) != 0) {
printf("test %d failed\n", cnt);
result = 1;
}
for (cnt = 0; cnt < ntests2; ++cnt) {
char *cp = crypt_sha512(tests2[cnt].input, tests2[cnt].salt);
if (strcmp(cp, tests2[cnt].expected) != 0) {
printf("test %d: expected \"%s\", got \"%s\"\n",
cnt, tests2[cnt].expected, cp);
result = 1;
}
}
if (result == 0)
puts("all tests OK");
return result;
}
#endif /* TEST */