linux-brain/crypto/md5.c
Jason A. Donenfeld 3c7eb3cc83 md5: remove from lib and only live in crypto
The md5_transform function is no longer used any where in the tree,
except for the crypto api's actual implementation of md5, so we can drop
the function from lib and put it as a static function of the crypto
file, where it belongs. There should be no new users of md5_transform,
anyway, since there are more modern ways of doing what it once achieved.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-03-24 22:02:56 +08:00

271 lines
7.7 KiB
C

/*
* Cryptographic API.
*
* MD5 Message Digest Algorithm (RFC1321).
*
* Derived from cryptoapi implementation, originally based on the
* public domain implementation written by Colin Plumb in 1993.
*
* Copyright (c) Cryptoapi developers.
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <crypto/internal/hash.h>
#include <crypto/md5.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/types.h>
#include <asm/byteorder.h>
#define MD5_DIGEST_WORDS 4
#define MD5_MESSAGE_BYTES 64
const u8 md5_zero_message_hash[MD5_DIGEST_SIZE] = {
0xd4, 0x1d, 0x8c, 0xd9, 0x8f, 0x00, 0xb2, 0x04,
0xe9, 0x80, 0x09, 0x98, 0xec, 0xf8, 0x42, 0x7e,
};
EXPORT_SYMBOL_GPL(md5_zero_message_hash);
/* XXX: this stuff can be optimized */
static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
{
while (words--) {
__le32_to_cpus(buf);
buf++;
}
}
static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
{
while (words--) {
__cpu_to_le32s(buf);
buf++;
}
}
#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))
#define MD5STEP(f, w, x, y, z, in, s) \
(w += f(x, y, z) + in, w = (w<<s | w>>(32-s)) + x)
static void md5_transform(__u32 *hash, __u32 const *in)
{
u32 a, b, c, d;
a = hash[0];
b = hash[1];
c = hash[2];
d = hash[3];
MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
hash[0] += a;
hash[1] += b;
hash[2] += c;
hash[3] += d;
}
static inline void md5_transform_helper(struct md5_state *ctx)
{
le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32));
md5_transform(ctx->hash, ctx->block);
}
static int md5_init(struct shash_desc *desc)
{
struct md5_state *mctx = shash_desc_ctx(desc);
mctx->hash[0] = MD5_H0;
mctx->hash[1] = MD5_H1;
mctx->hash[2] = MD5_H2;
mctx->hash[3] = MD5_H3;
mctx->byte_count = 0;
return 0;
}
static int md5_update(struct shash_desc *desc, const u8 *data, unsigned int len)
{
struct md5_state *mctx = shash_desc_ctx(desc);
const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);
mctx->byte_count += len;
if (avail > len) {
memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
data, len);
return 0;
}
memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
data, avail);
md5_transform_helper(mctx);
data += avail;
len -= avail;
while (len >= sizeof(mctx->block)) {
memcpy(mctx->block, data, sizeof(mctx->block));
md5_transform_helper(mctx);
data += sizeof(mctx->block);
len -= sizeof(mctx->block);
}
memcpy(mctx->block, data, len);
return 0;
}
static int md5_final(struct shash_desc *desc, u8 *out)
{
struct md5_state *mctx = shash_desc_ctx(desc);
const unsigned int offset = mctx->byte_count & 0x3f;
char *p = (char *)mctx->block + offset;
int padding = 56 - (offset + 1);
*p++ = 0x80;
if (padding < 0) {
memset(p, 0x00, padding + sizeof (u64));
md5_transform_helper(mctx);
p = (char *)mctx->block;
padding = 56;
}
memset(p, 0, padding);
mctx->block[14] = mctx->byte_count << 3;
mctx->block[15] = mctx->byte_count >> 29;
le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
sizeof(u64)) / sizeof(u32));
md5_transform(mctx->hash, mctx->block);
cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32));
memcpy(out, mctx->hash, sizeof(mctx->hash));
memset(mctx, 0, sizeof(*mctx));
return 0;
}
static int md5_export(struct shash_desc *desc, void *out)
{
struct md5_state *ctx = shash_desc_ctx(desc);
memcpy(out, ctx, sizeof(*ctx));
return 0;
}
static int md5_import(struct shash_desc *desc, const void *in)
{
struct md5_state *ctx = shash_desc_ctx(desc);
memcpy(ctx, in, sizeof(*ctx));
return 0;
}
static struct shash_alg alg = {
.digestsize = MD5_DIGEST_SIZE,
.init = md5_init,
.update = md5_update,
.final = md5_final,
.export = md5_export,
.import = md5_import,
.descsize = sizeof(struct md5_state),
.statesize = sizeof(struct md5_state),
.base = {
.cra_name = "md5",
.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.cra_blocksize = MD5_HMAC_BLOCK_SIZE,
.cra_module = THIS_MODULE,
}
};
static int __init md5_mod_init(void)
{
return crypto_register_shash(&alg);
}
static void __exit md5_mod_fini(void)
{
crypto_unregister_shash(&alg);
}
module_init(md5_mod_init);
module_exit(md5_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MD5 Message Digest Algorithm");
MODULE_ALIAS_CRYPTO("md5");