mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-14 08:57:58 +00:00
29bbe71ccf
In order to prevent using the global errno, replace it with a static version and create a wrapper function which returns the error value. Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de> Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Heiko Schocher <hs@denx.de>
336 lines
11 KiB
C
336 lines
11 KiB
C
// SPDX-License-Identifier: CC0-1.0
|
|
/* Based on libxcrypt v4.4.17-0-g6b110bc */
|
|
/* One way encryption based on the SHA256-based Unix crypt implementation.
|
|
*
|
|
* Written by Ulrich Drepper <drepper at redhat.com> in 2007 [1].
|
|
* Modified by Zack Weinberg <zackw at panix.com> in 2017, 2018.
|
|
* Composed by Björn Esser <besser82 at fedoraproject.org> in 2018.
|
|
* Modified by Björn Esser <besser82 at fedoraproject.org> in 2020.
|
|
* Modified by Steffen Jaeckel <jaeckel-floss at eyet-services.de> in 2021
|
|
* for U-Boot, instead of using the global errno to use a static one
|
|
* inside this file.
|
|
* To the extent possible under law, the named authors have waived all
|
|
* copyright and related or neighboring rights to this work.
|
|
*
|
|
* See https://creativecommons.org/publicdomain/zero/1.0/ for further
|
|
* details.
|
|
*
|
|
* This file is a modified except from [2], lines 648 up to 909.
|
|
*
|
|
* [1] https://www.akkadia.org/drepper/sha-crypt.html
|
|
* [2] https://www.akkadia.org/drepper/SHA-crypt.txt
|
|
*/
|
|
|
|
#include "crypt-port.h"
|
|
#include "alg-sha256.h"
|
|
|
|
#include <linux/errno.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
|
|
#if INCLUDE_sha256crypt
|
|
|
|
/* Define our magic string to mark salt for SHA256 "encryption"
|
|
replacement. */
|
|
static const char sha256_salt_prefix[] = "$5$";
|
|
|
|
/* Prefix for optional rounds specification. */
|
|
static const char sha256_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
|
|
|
|
/* The maximum possible length of a SHA256-hashed password string,
|
|
including the terminating NUL character. Prefix (including its NUL)
|
|
+ rounds tag ("rounds=$" = "rounds=\0") + strlen(ROUNDS_MAX)
|
|
+ salt (up to SALT_LEN_MAX chars) + '$' + hash (43 chars). */
|
|
|
|
#define LENGTH_OF_NUMBER(n) (sizeof #n - 1)
|
|
|
|
#define SHA256_HASH_LENGTH \
|
|
(sizeof (sha256_salt_prefix) + sizeof (sha256_rounds_prefix) + \
|
|
LENGTH_OF_NUMBER (ROUNDS_MAX) + SALT_LEN_MAX + 1 + 43)
|
|
|
|
static_assert (SHA256_HASH_LENGTH <= CRYPT_OUTPUT_SIZE,
|
|
"CRYPT_OUTPUT_SIZE is too small for SHA256");
|
|
|
|
/* A sha256_buffer holds all of the sensitive intermediate data. */
|
|
struct sha256_buffer
|
|
{
|
|
SHA256_CTX ctx;
|
|
uint8_t result[32];
|
|
uint8_t p_bytes[32];
|
|
uint8_t s_bytes[32];
|
|
};
|
|
|
|
static_assert (sizeof (struct sha256_buffer) <= ALG_SPECIFIC_SIZE,
|
|
"ALG_SPECIFIC_SIZE is too small for SHA256");
|
|
|
|
|
|
/* Use this instead of including errno.h */
|
|
static int errno;
|
|
|
|
void crypt_sha256crypt_rn(const char *phrase, size_t phr_size,
|
|
const char *setting, size_t ARG_UNUSED(set_size),
|
|
uint8_t *output, size_t out_size, void *scratch,
|
|
size_t scr_size);
|
|
|
|
int crypt_sha256crypt_rn_wrapped(const char *phrase, size_t phr_size,
|
|
const char *setting, size_t set_size,
|
|
u8 *output, size_t out_size, void *scratch,
|
|
size_t scr_size)
|
|
{
|
|
errno = 0;
|
|
crypt_sha256crypt_rn(phrase, phr_size, setting, set_size, output,
|
|
out_size, scratch, scr_size);
|
|
return -errno;
|
|
}
|
|
|
|
/* Feed CTX with LEN bytes of a virtual byte sequence consisting of
|
|
BLOCK repeated over and over indefinitely. */
|
|
static void
|
|
SHA256_Update_recycled (SHA256_CTX *ctx,
|
|
unsigned char block[32], size_t len)
|
|
{
|
|
size_t cnt;
|
|
for (cnt = len; cnt >= 32; cnt -= 32)
|
|
SHA256_Update (ctx, block, 32);
|
|
SHA256_Update (ctx, block, cnt);
|
|
}
|
|
|
|
void
|
|
crypt_sha256crypt_rn (const char *phrase, size_t phr_size,
|
|
const char *setting, size_t ARG_UNUSED (set_size),
|
|
uint8_t *output, size_t out_size,
|
|
void *scratch, size_t scr_size)
|
|
{
|
|
/* This shouldn't ever happen, but... */
|
|
if (out_size < SHA256_HASH_LENGTH
|
|
|| scr_size < sizeof (struct sha256_buffer))
|
|
{
|
|
errno = ERANGE;
|
|
return;
|
|
}
|
|
|
|
struct sha256_buffer *buf = scratch;
|
|
SHA256_CTX *ctx = &buf->ctx;
|
|
uint8_t *result = buf->result;
|
|
uint8_t *p_bytes = buf->p_bytes;
|
|
uint8_t *s_bytes = buf->s_bytes;
|
|
char *cp = (char *)output;
|
|
const char *salt = setting;
|
|
|
|
size_t salt_size;
|
|
size_t cnt;
|
|
/* Default number of rounds. */
|
|
size_t rounds = ROUNDS_DEFAULT;
|
|
bool rounds_custom = false;
|
|
|
|
/* Find beginning of salt string. The prefix should normally always
|
|
be present. Just in case it is not. */
|
|
if (strncmp (sha256_salt_prefix, salt, sizeof (sha256_salt_prefix) - 1) == 0)
|
|
/* Skip salt prefix. */
|
|
salt += sizeof (sha256_salt_prefix) - 1;
|
|
|
|
if (strncmp (salt, sha256_rounds_prefix, sizeof (sha256_rounds_prefix) - 1)
|
|
== 0)
|
|
{
|
|
const char *num = salt + sizeof (sha256_rounds_prefix) - 1;
|
|
/* Do not allow an explicit setting of zero rounds, nor of the
|
|
default number of rounds, nor leading zeroes on the rounds. */
|
|
if (!(*num >= '1' && *num <= '9'))
|
|
{
|
|
errno = EINVAL;
|
|
return;
|
|
}
|
|
|
|
errno = 0;
|
|
char *endp;
|
|
rounds = strtoul (num, &endp, 10);
|
|
if (endp == num || *endp != '$'
|
|
|| rounds < ROUNDS_MIN
|
|
|| rounds > ROUNDS_MAX
|
|
|| errno)
|
|
{
|
|
errno = EINVAL;
|
|
return;
|
|
}
|
|
salt = endp + 1;
|
|
rounds_custom = true;
|
|
}
|
|
|
|
/* The salt ends at the next '$' or the end of the string.
|
|
Ensure ':' does not appear in the salt (it is used as a separator in /etc/passwd).
|
|
Also check for '\n', as in /etc/passwd the whole parameters of the user data must
|
|
be on a single line. */
|
|
salt_size = strcspn (salt, "$:\n");
|
|
if (!(salt[salt_size] == '$' || !salt[salt_size]))
|
|
{
|
|
errno = EINVAL;
|
|
return;
|
|
}
|
|
|
|
/* Ensure we do not use more salt than SALT_LEN_MAX. */
|
|
if (salt_size > SALT_LEN_MAX)
|
|
salt_size = SALT_LEN_MAX;
|
|
|
|
/* Compute alternate SHA256 sum with input PHRASE, SALT, and PHRASE. The
|
|
final result will be added to the first context. */
|
|
SHA256_Init (ctx);
|
|
|
|
/* Add phrase. */
|
|
SHA256_Update (ctx, phrase, phr_size);
|
|
|
|
/* Add salt. */
|
|
SHA256_Update (ctx, salt, salt_size);
|
|
|
|
/* Add phrase again. */
|
|
SHA256_Update (ctx, phrase, phr_size);
|
|
|
|
/* Now get result of this (32 bytes). */
|
|
SHA256_Final (result, ctx);
|
|
|
|
/* Prepare for the real work. */
|
|
SHA256_Init (ctx);
|
|
|
|
/* Add the phrase string. */
|
|
SHA256_Update (ctx, phrase, phr_size);
|
|
|
|
/* 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). */
|
|
SHA256_Update (ctx, salt, salt_size);
|
|
|
|
/* Add for any character in the phrase one byte of the alternate sum. */
|
|
for (cnt = phr_size; cnt > 32; cnt -= 32)
|
|
SHA256_Update (ctx, result, 32);
|
|
SHA256_Update (ctx, result, cnt);
|
|
|
|
/* Take the binary representation of the length of the phrase and for every
|
|
1 add the alternate sum, for every 0 the phrase. */
|
|
for (cnt = phr_size; cnt > 0; cnt >>= 1)
|
|
if ((cnt & 1) != 0)
|
|
SHA256_Update (ctx, result, 32);
|
|
else
|
|
SHA256_Update (ctx, phrase, phr_size);
|
|
|
|
/* Create intermediate result. */
|
|
SHA256_Final (result, ctx);
|
|
|
|
/* Start computation of P byte sequence. */
|
|
SHA256_Init (ctx);
|
|
|
|
/* For every character in the password add the entire password. */
|
|
for (cnt = 0; cnt < phr_size; ++cnt)
|
|
SHA256_Update (ctx, phrase, phr_size);
|
|
|
|
/* Finish the digest. */
|
|
SHA256_Final (p_bytes, ctx);
|
|
|
|
/* Start computation of S byte sequence. */
|
|
SHA256_Init (ctx);
|
|
|
|
/* For every character in the password add the entire password. */
|
|
for (cnt = 0; cnt < (size_t) 16 + (size_t) result[0]; ++cnt)
|
|
SHA256_Update (ctx, salt, salt_size);
|
|
|
|
/* Finish the digest. */
|
|
SHA256_Final (s_bytes, ctx);
|
|
|
|
/* Repeatedly run the collected hash value through SHA256 to burn
|
|
CPU cycles. */
|
|
for (cnt = 0; cnt < rounds; ++cnt)
|
|
{
|
|
/* New context. */
|
|
SHA256_Init (ctx);
|
|
|
|
/* Add phrase or last result. */
|
|
if ((cnt & 1) != 0)
|
|
SHA256_Update_recycled (ctx, p_bytes, phr_size);
|
|
else
|
|
SHA256_Update (ctx, result, 32);
|
|
|
|
/* Add salt for numbers not divisible by 3. */
|
|
if (cnt % 3 != 0)
|
|
SHA256_Update_recycled (ctx, s_bytes, salt_size);
|
|
|
|
/* Add phrase for numbers not divisible by 7. */
|
|
if (cnt % 7 != 0)
|
|
SHA256_Update_recycled (ctx, p_bytes, phr_size);
|
|
|
|
/* Add phrase or last result. */
|
|
if ((cnt & 1) != 0)
|
|
SHA256_Update (ctx, result, 32);
|
|
else
|
|
SHA256_Update_recycled (ctx, p_bytes, phr_size);
|
|
|
|
/* Create intermediate result. */
|
|
SHA256_Final (result, ctx);
|
|
}
|
|
|
|
/* Now we can construct the result string. It consists of four
|
|
parts, one of which is optional. We already know that there
|
|
is sufficient space at CP for the longest possible result string. */
|
|
memcpy (cp, sha256_salt_prefix, sizeof (sha256_salt_prefix) - 1);
|
|
cp += sizeof (sha256_salt_prefix) - 1;
|
|
|
|
if (rounds_custom)
|
|
{
|
|
int n = snprintf (cp,
|
|
SHA256_HASH_LENGTH - (sizeof (sha256_salt_prefix) - 1),
|
|
"%s%zu$", sha256_rounds_prefix, rounds);
|
|
cp += n;
|
|
}
|
|
|
|
memcpy (cp, salt, salt_size);
|
|
cp += salt_size;
|
|
*cp++ = '$';
|
|
|
|
#define b64_from_24bit(B2, B1, B0, N) \
|
|
do { \
|
|
unsigned int w = ((((unsigned int)(B2)) << 16) | \
|
|
(((unsigned int)(B1)) << 8) | \
|
|
((unsigned int)(B0))); \
|
|
int n = (N); \
|
|
while (n-- > 0) \
|
|
{ \
|
|
*cp++ = b64t[w & 0x3f]; \
|
|
w >>= 6; \
|
|
} \
|
|
} while (0)
|
|
|
|
b64_from_24bit (result[0], result[10], result[20], 4);
|
|
b64_from_24bit (result[21], result[1], result[11], 4);
|
|
b64_from_24bit (result[12], result[22], result[2], 4);
|
|
b64_from_24bit (result[3], result[13], result[23], 4);
|
|
b64_from_24bit (result[24], result[4], result[14], 4);
|
|
b64_from_24bit (result[15], result[25], result[5], 4);
|
|
b64_from_24bit (result[6], result[16], result[26], 4);
|
|
b64_from_24bit (result[27], result[7], result[17], 4);
|
|
b64_from_24bit (result[18], result[28], result[8], 4);
|
|
b64_from_24bit (result[9], result[19], result[29], 4);
|
|
b64_from_24bit (0, result[31], result[30], 3);
|
|
|
|
*cp = '\0';
|
|
}
|
|
|
|
#ifndef NO_GENSALT
|
|
|
|
void
|
|
gensalt_sha256crypt_rn (unsigned long count,
|
|
const uint8_t *rbytes, size_t nrbytes,
|
|
uint8_t *output, size_t output_size)
|
|
{
|
|
gensalt_sha_rn ('5', SALT_LEN_MAX, ROUNDS_DEFAULT, ROUNDS_MIN, ROUNDS_MAX,
|
|
count, rbytes, nrbytes, output, output_size);
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif
|