void-packages/lib/sha256.c

387 lines
12 KiB
C

/*
* Written by Aaron D. Gifford <me@aarongifford.com>
*
* Copyright 2000 Aaron D. Gifford. 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.
* 3. Neither the name of the copyright holder nor the names of contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) AND CONTRIBUTOR(S) ``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(S) OR CONTRIBUTOR(S) 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.
*
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <inttypes.h>
#include <libgen.h>
#include <xbps_api.h>
/*** SHA-256 Machine Architecture Definitions *****************/
/*** SHA-256 Various Length Definitions ***********************/
/* NOTE: Most of these are in sha2.h */
#define SHA256_SHORT_BLOCK_LENGTH (SHA256_BLOCK_LENGTH - 8)
/*** ENDIAN REVERSAL MACROS *******************************************/
#ifndef WORDS_BIGENDIAN
#define REVERSE32(w,x) { \
sha2_word32 tmp = (w); \
tmp = (tmp >> 16) | (tmp << 16); \
(x) = ((tmp & 0xff00ff00UL) >> 8) | ((tmp & 0x00ff00ffUL) << 8); \
}
#define REVERSE64(w,x) { \
sha2_word64 tmp = (w); \
tmp = (tmp >> 32) | (tmp << 32); \
tmp = ((tmp & 0xff00ff00ff00ff00ULL) >> 8) | \
((tmp & 0x00ff00ff00ff00ffULL) << 8); \
(x) = ((tmp & 0xffff0000ffff0000ULL) >> 16) | \
((tmp & 0x0000ffff0000ffffULL) << 16); \
}
#endif /* WORDS_BIGENDIAN */
/*** THE SIX LOGICAL FUNCTIONS ****************************************/
/*
* Bit shifting and rotation (used by the six SHA-XYZ logical functions:
*
* NOTE: The naming of R and S appears backwards here (R is a SHIFT and
* S is a ROTATION) because the SHA-256/384/512 description document
* (see http://csrc.nist.gov/cryptval/shs/sha256-384-512.pdf) uses this
* same "backwards" definition.
*/
/* Shift-right (used in SHA-256, SHA-384, and SHA-512): */
#define R(b,x) ((x) >> (b))
/* 32-bit Rotate-right (used in SHA-256): */
#define S32(b,x) (((x) >> (b)) | ((x) << (32 - (b))))
/* Two of six logical functions used in SHA-256, SHA-384, and SHA-512: */
#define Ch(x,y,z) (((x) & (y)) ^ ((~(x)) & (z)))
#define Maj(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
/* Four of six logical functions used in SHA-256: */
#define Sigma0_256(x) (S32(2, (x)) ^ S32(13, (x)) ^ S32(22, (x)))
#define Sigma1_256(x) (S32(6, (x)) ^ S32(11, (x)) ^ S32(25, (x)))
#define sigma0_256(x) (S32(7, (x)) ^ S32(18, (x)) ^ R(3 , (x)))
#define sigma1_256(x) (S32(17, (x)) ^ S32(19, (x)) ^ R(10, (x)))
/*** SHA-XYZ INITIAL HASH VALUES AND CONSTANTS ************************/
/* Hash constant words K for SHA-256: */
static const sha2_word32 K256[64] = {
0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,
0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
};
/* Initial hash value H for SHA-256: */
static const sha2_word32 sha256_initial_hash_value[8] = {
0x6a09e667UL,
0xbb67ae85UL,
0x3c6ef372UL,
0xa54ff53aUL,
0x510e527fUL,
0x9b05688cUL,
0x1f83d9abUL,
0x5be0cd19UL
};
/* Unrolled SHA-256 round macros: */
#ifndef WORDS_BIGENDIAN
#define ROUND256_0_TO_15(a,b,c,d,e,f,g,h) \
REVERSE32(*data++, W256[j]); \
T1 = (h) + Sigma1_256(e) + Ch((e), (f), (g)) + \
K256[j] + W256[j]; \
(d) += T1; \
(h) = T1 + Sigma0_256(a) + Maj((a), (b), (c)); \
j++
#else /* WORDS__BIGENDIAN */
#define ROUND256_0_TO_15(a,b,c,d,e,f,g,h) \
T1 = (h) + Sigma1_256(e) + Ch((e), (f), (g)) + \
K256[j] + (W256[j] = *data++); \
(d) += T1; \
(h) = T1 + Sigma0_256(a) + Maj((a), (b), (c)); \
j++
#endif /* WORDS_BIGENDIAN */
#define ROUND256(a,b,c,d,e,f,g,h) \
s0 = W256[(j+1)&0x0f]; \
s0 = sigma0_256(s0); \
s1 = W256[(j+14)&0x0f]; \
s1 = sigma1_256(s1); \
T1 = (h) + Sigma1_256(e) + Ch((e), (f), (g)) + K256[j] + \
(W256[j&0x0f] += s1 + W256[(j+9)&0x0f] + s0); \
(d) += T1; \
(h) = T1 + Sigma0_256(a) + Maj((a), (b), (c)); \
j++
static void SHA256_Final(uint8_t[SHA256_DIGEST_LENGTH], SHA256_CTX*);
static void SHA256_Transform(SHA256_CTX*, const sha2_word32*);
/*** SHA-256: *********************************************************/
void SHA256_Init(SHA256_CTX* context)
{
if (context == (SHA256_CTX*)0) {
return;
}
memcpy(context->state, sha256_initial_hash_value, SHA256_DIGEST_LENGTH);
memset(context->buffer, 0, SHA256_BLOCK_LENGTH);
context->bitcount = 0;
}
static void
SHA256_Transform(SHA256_CTX* context, const sha2_word32* data)
{
sha2_word32 a, b, c, d, e, f, g, h, s0, s1;
sha2_word32 T1, *W256;
int j;
W256 = (sha2_word32*)context->buffer;
/* Initialize registers with the prev. intermediate value */
a = context->state[0];
b = context->state[1];
c = context->state[2];
d = context->state[3];
e = context->state[4];
f = context->state[5];
g = context->state[6];
h = context->state[7];
j = 0;
do {
/* Rounds 0 to 15 (unrolled): */
ROUND256_0_TO_15(a,b,c,d,e,f,g,h);
ROUND256_0_TO_15(h,a,b,c,d,e,f,g);
ROUND256_0_TO_15(g,h,a,b,c,d,e,f);
ROUND256_0_TO_15(f,g,h,a,b,c,d,e);
ROUND256_0_TO_15(e,f,g,h,a,b,c,d);
ROUND256_0_TO_15(d,e,f,g,h,a,b,c);
ROUND256_0_TO_15(c,d,e,f,g,h,a,b);
ROUND256_0_TO_15(b,c,d,e,f,g,h,a);
} while (j < 16);
/* Now for the remaining rounds to 64: */
do {
ROUND256(a,b,c,d,e,f,g,h);
ROUND256(h,a,b,c,d,e,f,g);
ROUND256(g,h,a,b,c,d,e,f);
ROUND256(f,g,h,a,b,c,d,e);
ROUND256(e,f,g,h,a,b,c,d);
ROUND256(d,e,f,g,h,a,b,c);
ROUND256(c,d,e,f,g,h,a,b);
ROUND256(b,c,d,e,f,g,h,a);
} while (j < 64);
/* Compute the current intermediate hash value */
context->state[0] += a;
context->state[1] += b;
context->state[2] += c;
context->state[3] += d;
context->state[4] += e;
context->state[5] += f;
context->state[6] += g;
context->state[7] += h;
/* Clean up */
a = b = c = d = e = f = g = h = T1 = 0;
}
void
SHA256_Update(SHA256_CTX* context, const uint8_t *data, size_t len)
{
unsigned int freespace, usedspace;
if (len == 0) {
/* Calling with no data is valid - we do nothing */
return;
}
/* Sanity check: */
assert(context != NULL && data != NULL);
usedspace =
(unsigned int)(context->bitcount >> 3) % SHA256_BLOCK_LENGTH;
if (usedspace > 0) {
/* Calculate how much free space is available in the buffer */
freespace = SHA256_BLOCK_LENGTH - usedspace;
if (len >= freespace) {
/* Fill the buffer completely and process it */
memcpy(&context->buffer[usedspace], data, freespace);
context->bitcount += freespace << 3;
len -= freespace;
data += freespace;
SHA256_Transform(context,
(sha2_word32*)context->buffer);
} else {
/* The buffer is not yet full */
memcpy(&context->buffer[usedspace], data, len);
context->bitcount += len << 3;
/* Clean up: */
usedspace = freespace = 0;
return;
}
}
while (len >= SHA256_BLOCK_LENGTH) {
/* Process as many complete blocks as we can */
SHA256_Transform(context, (const sha2_word32*)data);
context->bitcount += SHA256_BLOCK_LENGTH << 3;
len -= SHA256_BLOCK_LENGTH;
data += SHA256_BLOCK_LENGTH;
}
if (len > 0) {
/* There's left-overs, so save 'em */
memcpy(context->buffer, data, len);
context->bitcount += len << 3;
}
/* Clean up: */
usedspace = freespace = 0;
}
static void
SHA256_Final(sha2_byte digest[], SHA256_CTX* context)
{
sha2_word32 *d = (sha2_word32*)digest;
unsigned int usedspace;
/* Sanity check: */
assert(context != NULL);
/* If no digest buffer is passed, we don't bother doing this: */
if (digest != (sha2_byte*)0) {
usedspace =
(unsigned int)(context->bitcount >> 3) % SHA256_BLOCK_LENGTH;
#ifndef WORDS_BIGENDIAN
/* Convert FROM host byte order */
REVERSE64(context->bitcount,context->bitcount);
#endif
if (usedspace > 0) {
/* Begin padding with a 1 bit: */
context->buffer[usedspace++] = 0x80;
if (usedspace <= SHA256_SHORT_BLOCK_LENGTH) {
/* Set-up for the last transform: */
memset(&context->buffer[usedspace], 0,
SHA256_SHORT_BLOCK_LENGTH - usedspace);
} else {
if (usedspace < SHA256_BLOCK_LENGTH) {
memset(&context->buffer[usedspace], 0,
SHA256_BLOCK_LENGTH - usedspace);
}
/* Do second-to-last transform: */
SHA256_Transform(context,
(sha2_word32*)context->buffer);
/* And set-up for the last transform: */
memset(context->buffer, 0,
SHA256_SHORT_BLOCK_LENGTH);
}
} else {
/* Set-up for the last transform: */
memset(context->buffer, 0, SHA256_SHORT_BLOCK_LENGTH);
/* Begin padding with a 1 bit: */
*context->buffer = 0x80;
}
/* Set the bit count: */
*(sha2_word64*)&context->buffer[SHA256_SHORT_BLOCK_LENGTH] =
context->bitcount;
/* Final transform: */
SHA256_Transform(context, (sha2_word32*)context->buffer);
#ifndef WORDS_BIGENDIAN
{
/* Convert TO host byte order */
int j;
for (j = 0; j < 8; j++) {
REVERSE32(context->state[j],context->state[j]);
*d++ = context->state[j];
}
}
#else
memcpy(d, context->state, SHA256_DIGEST_LENGTH);
#endif
}
/* Clean up state data: */
memset(context, 0, sizeof(SHA256_CTX));
usedspace = 0;
}
/*
* Constant used by SHA256/384/512_End() functions for converting the
* digest to a readable hexadecimal character string:
*/
static const char sha2_hex_digits[] = "0123456789abcdef";
char *
SHA256_End(SHA256_CTX *ctx, uint8_t *buffer)
{
uint8_t digest[SHA256_DIGEST_LENGTH], *d = digest;
uint8_t *ret;
int i;
/* Sanity check: */
assert(ctx != NULL);
if ((ret = buffer) != NULL) {
SHA256_Final(digest, ctx);
for (i = 0; i < SHA256_DIGEST_LENGTH; i++) {
*buffer++ = (uint8_t)sha2_hex_digits[(*d & 0xf0) >> 4];
*buffer++ = (uint8_t)sha2_hex_digits[*d & 0x0f];
d++;
}
*buffer = (char) 0;
} else {
(void)memset(ctx, 0, sizeof(SHA256_CTX));
}
(void)memset(digest, 0, SHA256_DIGEST_LENGTH);
return (char *)ret;
}