linux/lib/crypto/sha256.c
Eric Biggers a24d22b225 crypto: sha - split sha.h into sha1.h and sha2.h
Currently <crypto/sha.h> contains declarations for both SHA-1 and SHA-2,
and <crypto/sha3.h> contains declarations for SHA-3.

This organization is inconsistent, but more importantly SHA-1 is no
longer considered to be cryptographically secure.  So to the extent
possible, SHA-1 shouldn't be grouped together with any of the other SHA
versions, and usage of it should be phased out.

Therefore, split <crypto/sha.h> into two headers <crypto/sha1.h> and
<crypto/sha2.h>, and make everyone explicitly specify whether they want
the declarations for SHA-1, SHA-2, or both.

This avoids making the SHA-1 declarations visible to files that don't
want anything to do with SHA-1.  It also prepares for potentially moving
sha1.h into a new insecure/ or dangerous/ directory.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-11-20 14:45:33 +11:00

210 lines
5.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* SHA-256, as specified in
* http://csrc.nist.gov/groups/STM/cavp/documents/shs/sha256-384-512.pdf
*
* SHA-256 code by Jean-Luc Cooke <jlcooke@certainkey.com>.
*
* Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
* Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
* Copyright (c) 2014 Red Hat Inc.
*/
#include <linux/bitops.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/string.h>
#include <crypto/sha2.h>
#include <asm/unaligned.h>
static const u32 SHA256_K[] = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
};
static inline u32 Ch(u32 x, u32 y, u32 z)
{
return z ^ (x & (y ^ z));
}
static inline u32 Maj(u32 x, u32 y, u32 z)
{
return (x & y) | (z & (x | y));
}
#define e0(x) (ror32(x, 2) ^ ror32(x, 13) ^ ror32(x, 22))
#define e1(x) (ror32(x, 6) ^ ror32(x, 11) ^ ror32(x, 25))
#define s0(x) (ror32(x, 7) ^ ror32(x, 18) ^ (x >> 3))
#define s1(x) (ror32(x, 17) ^ ror32(x, 19) ^ (x >> 10))
static inline void LOAD_OP(int I, u32 *W, const u8 *input)
{
W[I] = get_unaligned_be32((__u32 *)input + I);
}
static inline void BLEND_OP(int I, u32 *W)
{
W[I] = s1(W[I-2]) + W[I-7] + s0(W[I-15]) + W[I-16];
}
#define SHA256_ROUND(i, a, b, c, d, e, f, g, h) do { \
u32 t1, t2; \
t1 = h + e1(e) + Ch(e, f, g) + SHA256_K[i] + W[i]; \
t2 = e0(a) + Maj(a, b, c); \
d += t1; \
h = t1 + t2; \
} while (0)
static void sha256_transform(u32 *state, const u8 *input, u32 *W)
{
u32 a, b, c, d, e, f, g, h;
int i;
/* load the input */
for (i = 0; i < 16; i += 8) {
LOAD_OP(i + 0, W, input);
LOAD_OP(i + 1, W, input);
LOAD_OP(i + 2, W, input);
LOAD_OP(i + 3, W, input);
LOAD_OP(i + 4, W, input);
LOAD_OP(i + 5, W, input);
LOAD_OP(i + 6, W, input);
LOAD_OP(i + 7, W, input);
}
/* now blend */
for (i = 16; i < 64; i += 8) {
BLEND_OP(i + 0, W);
BLEND_OP(i + 1, W);
BLEND_OP(i + 2, W);
BLEND_OP(i + 3, W);
BLEND_OP(i + 4, W);
BLEND_OP(i + 5, W);
BLEND_OP(i + 6, W);
BLEND_OP(i + 7, W);
}
/* load the state into our registers */
a = state[0]; b = state[1]; c = state[2]; d = state[3];
e = state[4]; f = state[5]; g = state[6]; h = state[7];
/* now iterate */
for (i = 0; i < 64; i += 8) {
SHA256_ROUND(i + 0, a, b, c, d, e, f, g, h);
SHA256_ROUND(i + 1, h, a, b, c, d, e, f, g);
SHA256_ROUND(i + 2, g, h, a, b, c, d, e, f);
SHA256_ROUND(i + 3, f, g, h, a, b, c, d, e);
SHA256_ROUND(i + 4, e, f, g, h, a, b, c, d);
SHA256_ROUND(i + 5, d, e, f, g, h, a, b, c);
SHA256_ROUND(i + 6, c, d, e, f, g, h, a, b);
SHA256_ROUND(i + 7, b, c, d, e, f, g, h, a);
}
state[0] += a; state[1] += b; state[2] += c; state[3] += d;
state[4] += e; state[5] += f; state[6] += g; state[7] += h;
}
void sha256_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
{
unsigned int partial, done;
const u8 *src;
u32 W[64];
partial = sctx->count & 0x3f;
sctx->count += len;
done = 0;
src = data;
if ((partial + len) > 63) {
if (partial) {
done = -partial;
memcpy(sctx->buf + partial, data, done + 64);
src = sctx->buf;
}
do {
sha256_transform(sctx->state, src, W);
done += 64;
src = data + done;
} while (done + 63 < len);
memzero_explicit(W, sizeof(W));
partial = 0;
}
memcpy(sctx->buf + partial, src, len - done);
}
EXPORT_SYMBOL(sha256_update);
void sha224_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
{
sha256_update(sctx, data, len);
}
EXPORT_SYMBOL(sha224_update);
static void __sha256_final(struct sha256_state *sctx, u8 *out, int digest_words)
{
__be32 *dst = (__be32 *)out;
__be64 bits;
unsigned int index, pad_len;
int i;
static const u8 padding[64] = { 0x80, };
/* Save number of bits */
bits = cpu_to_be64(sctx->count << 3);
/* Pad out to 56 mod 64. */
index = sctx->count & 0x3f;
pad_len = (index < 56) ? (56 - index) : ((64+56) - index);
sha256_update(sctx, padding, pad_len);
/* Append length (before padding) */
sha256_update(sctx, (const u8 *)&bits, sizeof(bits));
/* Store state in digest */
for (i = 0; i < digest_words; i++)
put_unaligned_be32(sctx->state[i], &dst[i]);
/* Zeroize sensitive information. */
memzero_explicit(sctx, sizeof(*sctx));
}
void sha256_final(struct sha256_state *sctx, u8 *out)
{
__sha256_final(sctx, out, 8);
}
EXPORT_SYMBOL(sha256_final);
void sha224_final(struct sha256_state *sctx, u8 *out)
{
__sha256_final(sctx, out, 7);
}
EXPORT_SYMBOL(sha224_final);
void sha256(const u8 *data, unsigned int len, u8 *out)
{
struct sha256_state sctx;
sha256_init(&sctx);
sha256_update(&sctx, data, len);
sha256_final(&sctx, out);
}
EXPORT_SYMBOL(sha256);
MODULE_LICENSE("GPL");