freebsd-dev/sys/crypto/sha2/sha256c.c
Conrad Meyer 571ebf7685 crypto routines: Hint minimum buffer sizes to the compiler
Use the C99 'static' keyword to hint to the compiler IVs and output digest
sizes.  The keyword informs the compiler of the minimum valid size for a given
array.  Obviously not every pointer can be validated (i.e., the compiler can
produce false negative but not false positive reports).

No functional change.  No ABI change.

Sponsored by:	EMC / Isilon Storage Division
2016-05-26 19:29:29 +00:00

317 lines
8.6 KiB
C

/*-
* Copyright 2005 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/endian.h>
#include <sys/types.h>
#ifdef _KERNEL
#include <sys/systm.h>
#else
#include <string.h>
#endif
#include "sha256.h"
#if BYTE_ORDER == BIG_ENDIAN
/* Copy a vector of big-endian uint32_t into a vector of bytes */
#define be32enc_vect(dst, src, len) \
memcpy((void *)dst, (const void *)src, (size_t)len)
/* Copy a vector of bytes into a vector of big-endian uint32_t */
#define be32dec_vect(dst, src, len) \
memcpy((void *)dst, (const void *)src, (size_t)len)
#else /* BYTE_ORDER != BIG_ENDIAN */
/*
* Encode a length len/4 vector of (uint32_t) into a length len vector of
* (unsigned char) in big-endian form. Assumes len is a multiple of 4.
*/
static void
be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len)
{
size_t i;
for (i = 0; i < len / 4; i++)
be32enc(dst + i * 4, src[i]);
}
/*
* Decode a big-endian length len vector of (unsigned char) into a length
* len/4 vector of (uint32_t). Assumes len is a multiple of 4.
*/
static void
be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len)
{
size_t i;
for (i = 0; i < len / 4; i++)
dst[i] = be32dec(src + i * 4);
}
#endif /* BYTE_ORDER != BIG_ENDIAN */
/* Elementary functions used by SHA256 */
#define Ch(x, y, z) ((x & (y ^ z)) ^ z)
#define Maj(x, y, z) ((x & (y | z)) | (y & z))
#define SHR(x, n) (x >> n)
#define ROTR(x, n) ((x >> n) | (x << (32 - n)))
#define S0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
#define S1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
#define s0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
#define s1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
/* SHA256 round function */
#define RND(a, b, c, d, e, f, g, h, k) \
t0 = h + S1(e) + Ch(e, f, g) + k; \
t1 = S0(a) + Maj(a, b, c); \
d += t0; \
h = t0 + t1;
/* Adjusted round function for rotating state */
#define RNDr(S, W, i, k) \
RND(S[(64 - i) % 8], S[(65 - i) % 8], \
S[(66 - i) % 8], S[(67 - i) % 8], \
S[(68 - i) % 8], S[(69 - i) % 8], \
S[(70 - i) % 8], S[(71 - i) % 8], \
W[i] + k)
/*
* SHA256 block compression function. The 256-bit state is transformed via
* the 512-bit input block to produce a new state.
*/
static void
SHA256_Transform(uint32_t * state, const unsigned char block[64])
{
uint32_t W[64];
uint32_t S[8];
uint32_t t0, t1;
int i;
/* 1. Prepare message schedule W. */
be32dec_vect(W, block, 64);
for (i = 16; i < 64; i++)
W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16];
/* 2. Initialize working variables. */
memcpy(S, state, 32);
/* 3. Mix. */
RNDr(S, W, 0, 0x428a2f98);
RNDr(S, W, 1, 0x71374491);
RNDr(S, W, 2, 0xb5c0fbcf);
RNDr(S, W, 3, 0xe9b5dba5);
RNDr(S, W, 4, 0x3956c25b);
RNDr(S, W, 5, 0x59f111f1);
RNDr(S, W, 6, 0x923f82a4);
RNDr(S, W, 7, 0xab1c5ed5);
RNDr(S, W, 8, 0xd807aa98);
RNDr(S, W, 9, 0x12835b01);
RNDr(S, W, 10, 0x243185be);
RNDr(S, W, 11, 0x550c7dc3);
RNDr(S, W, 12, 0x72be5d74);
RNDr(S, W, 13, 0x80deb1fe);
RNDr(S, W, 14, 0x9bdc06a7);
RNDr(S, W, 15, 0xc19bf174);
RNDr(S, W, 16, 0xe49b69c1);
RNDr(S, W, 17, 0xefbe4786);
RNDr(S, W, 18, 0x0fc19dc6);
RNDr(S, W, 19, 0x240ca1cc);
RNDr(S, W, 20, 0x2de92c6f);
RNDr(S, W, 21, 0x4a7484aa);
RNDr(S, W, 22, 0x5cb0a9dc);
RNDr(S, W, 23, 0x76f988da);
RNDr(S, W, 24, 0x983e5152);
RNDr(S, W, 25, 0xa831c66d);
RNDr(S, W, 26, 0xb00327c8);
RNDr(S, W, 27, 0xbf597fc7);
RNDr(S, W, 28, 0xc6e00bf3);
RNDr(S, W, 29, 0xd5a79147);
RNDr(S, W, 30, 0x06ca6351);
RNDr(S, W, 31, 0x14292967);
RNDr(S, W, 32, 0x27b70a85);
RNDr(S, W, 33, 0x2e1b2138);
RNDr(S, W, 34, 0x4d2c6dfc);
RNDr(S, W, 35, 0x53380d13);
RNDr(S, W, 36, 0x650a7354);
RNDr(S, W, 37, 0x766a0abb);
RNDr(S, W, 38, 0x81c2c92e);
RNDr(S, W, 39, 0x92722c85);
RNDr(S, W, 40, 0xa2bfe8a1);
RNDr(S, W, 41, 0xa81a664b);
RNDr(S, W, 42, 0xc24b8b70);
RNDr(S, W, 43, 0xc76c51a3);
RNDr(S, W, 44, 0xd192e819);
RNDr(S, W, 45, 0xd6990624);
RNDr(S, W, 46, 0xf40e3585);
RNDr(S, W, 47, 0x106aa070);
RNDr(S, W, 48, 0x19a4c116);
RNDr(S, W, 49, 0x1e376c08);
RNDr(S, W, 50, 0x2748774c);
RNDr(S, W, 51, 0x34b0bcb5);
RNDr(S, W, 52, 0x391c0cb3);
RNDr(S, W, 53, 0x4ed8aa4a);
RNDr(S, W, 54, 0x5b9cca4f);
RNDr(S, W, 55, 0x682e6ff3);
RNDr(S, W, 56, 0x748f82ee);
RNDr(S, W, 57, 0x78a5636f);
RNDr(S, W, 58, 0x84c87814);
RNDr(S, W, 59, 0x8cc70208);
RNDr(S, W, 60, 0x90befffa);
RNDr(S, W, 61, 0xa4506ceb);
RNDr(S, W, 62, 0xbef9a3f7);
RNDr(S, W, 63, 0xc67178f2);
/* 4. Mix local working variables into global state */
for (i = 0; i < 8; i++)
state[i] += S[i];
}
static unsigned char PAD[64] = {
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
/* Add padding and terminating bit-count. */
static void
SHA256_Pad(SHA256_CTX * ctx)
{
unsigned char len[8];
uint32_t r, plen;
/*
* Convert length to a vector of bytes -- we do this now rather
* than later because the length will change after we pad.
*/
be64enc(len, ctx->count);
/* Add 1--64 bytes so that the resulting length is 56 mod 64 */
r = (ctx->count >> 3) & 0x3f;
plen = (r < 56) ? (56 - r) : (120 - r);
SHA256_Update(ctx, PAD, (size_t)plen);
/* Add the terminating bit-count */
SHA256_Update(ctx, len, 8);
}
/* SHA-256 initialization. Begins a SHA-256 operation. */
void
SHA256_Init(SHA256_CTX * ctx)
{
/* Zero bits processed so far */
ctx->count = 0;
/* Magic initialization constants */
ctx->state[0] = 0x6A09E667;
ctx->state[1] = 0xBB67AE85;
ctx->state[2] = 0x3C6EF372;
ctx->state[3] = 0xA54FF53A;
ctx->state[4] = 0x510E527F;
ctx->state[5] = 0x9B05688C;
ctx->state[6] = 0x1F83D9AB;
ctx->state[7] = 0x5BE0CD19;
}
/* Add bytes into the hash */
void
SHA256_Update(SHA256_CTX * ctx, const void *in, size_t len)
{
uint64_t bitlen;
uint32_t r;
const unsigned char *src = in;
/* Number of bytes left in the buffer from previous updates */
r = (ctx->count >> 3) & 0x3f;
/* Convert the length into a number of bits */
bitlen = len << 3;
/* Update number of bits */
ctx->count += bitlen;
/* Handle the case where we don't need to perform any transforms */
if (len < 64 - r) {
memcpy(&ctx->buf[r], src, len);
return;
}
/* Finish the current block */
memcpy(&ctx->buf[r], src, 64 - r);
SHA256_Transform(ctx->state, ctx->buf);
src += 64 - r;
len -= 64 - r;
/* Perform complete blocks */
while (len >= 64) {
SHA256_Transform(ctx->state, src);
src += 64;
len -= 64;
}
/* Copy left over data into buffer */
memcpy(ctx->buf, src, len);
}
/*
* SHA-256 finalization. Pads the input data, exports the hash value,
* and clears the context state.
*/
void
SHA256_Final(unsigned char digest[static SHA256_DIGEST_LENGTH], SHA256_CTX *ctx)
{
/* Add padding */
SHA256_Pad(ctx);
/* Write the hash */
be32enc_vect(digest, ctx->state, SHA256_DIGEST_LENGTH);
/* Clear the context state */
memset(ctx, 0, sizeof(*ctx));
}
#ifdef WEAK_REFS
/* When building libmd, provide weak references. Note: this is not
activated in the context of compiling these sources for internal
use in libcrypt.
*/
#undef SHA256_Init
__weak_reference(_libmd_SHA256_Init, SHA256_Init);
#undef SHA256_Update
__weak_reference(_libmd_SHA256_Update, SHA256_Update);
#undef SHA256_Final
__weak_reference(_libmd_SHA256_Final, SHA256_Final);
#undef SHA256_Transform
__weak_reference(_libmd_SHA256_Transform, SHA256_Transform);
#endif