blob: c728bd0ae1ed987b8b222f8df7ce02a2fabcabe8 [file] [log] [blame]
/*
* Cryptographic API.
*
* s390 implementation of the SHA256 Secure Hash Algorithm.
*
* s390 Version:
* Copyright IBM Corp. 2005,2007
* Author(s): Jan Glauber (jang@de.ibm.com)
*
* Derived from "crypto/sha256_generic.c"
* and "arch/s390/crypto/sha1_s390.c"
*
* 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 <linux/init.h>
#include <linux/module.h>
#include <linux/crypto.h>
#include "crypt_s390.h"
#define SHA256_DIGEST_SIZE 32
#define SHA256_BLOCK_SIZE 64
struct s390_sha256_ctx {
u64 count; /* message length */
u32 state[8];
u8 buf[2 * SHA256_BLOCK_SIZE];
};
static void sha256_init(struct crypto_tfm *tfm)
{
struct s390_sha256_ctx *sctx = crypto_tfm_ctx(tfm);
sctx->state[0] = 0x6a09e667;
sctx->state[1] = 0xbb67ae85;
sctx->state[2] = 0x3c6ef372;
sctx->state[3] = 0xa54ff53a;
sctx->state[4] = 0x510e527f;
sctx->state[5] = 0x9b05688c;
sctx->state[6] = 0x1f83d9ab;
sctx->state[7] = 0x5be0cd19;
sctx->count = 0;
}
static void sha256_update(struct crypto_tfm *tfm, const u8 *data,
unsigned int len)
{
struct s390_sha256_ctx *sctx = crypto_tfm_ctx(tfm);
unsigned int index;
int ret;
/* how much is already in the buffer? */
index = sctx->count & 0x3f;
sctx->count += len;
if ((index + len) < SHA256_BLOCK_SIZE)
goto store;
/* process one stored block */
if (index) {
memcpy(sctx->buf + index, data, SHA256_BLOCK_SIZE - index);
ret = crypt_s390_kimd(KIMD_SHA_256, sctx->state, sctx->buf,
SHA256_BLOCK_SIZE);
BUG_ON(ret != SHA256_BLOCK_SIZE);
data += SHA256_BLOCK_SIZE - index;
len -= SHA256_BLOCK_SIZE - index;
}
/* process as many blocks as possible */
if (len >= SHA256_BLOCK_SIZE) {
ret = crypt_s390_kimd(KIMD_SHA_256, sctx->state, data,
len & ~(SHA256_BLOCK_SIZE - 1));
BUG_ON(ret != (len & ~(SHA256_BLOCK_SIZE - 1)));
data += ret;
len -= ret;
}
store:
/* anything left? */
if (len)
memcpy(sctx->buf + index , data, len);
}
/* Add padding and return the message digest */
static void sha256_final(struct crypto_tfm *tfm, u8 *out)
{
struct s390_sha256_ctx *sctx = crypto_tfm_ctx(tfm);
u64 bits;
unsigned int index, end;
int ret;
/* must perform manual padding */
index = sctx->count & 0x3f;
end = (index < 56) ? SHA256_BLOCK_SIZE : (2 * SHA256_BLOCK_SIZE);
/* start pad with 1 */
sctx->buf[index] = 0x80;
/* pad with zeros */
index++;
memset(sctx->buf + index, 0x00, end - index - 8);
/* append message length */
bits = sctx->count * 8;
memcpy(sctx->buf + end - 8, &bits, sizeof(bits));
ret = crypt_s390_kimd(KIMD_SHA_256, sctx->state, sctx->buf, end);
BUG_ON(ret != end);
/* copy digest to out */
memcpy(out, sctx->state, SHA256_DIGEST_SIZE);
/* wipe context */
memset(sctx, 0, sizeof *sctx);
}
static struct crypto_alg alg = {
.cra_name = "sha256",
.cra_driver_name = "sha256-s390",
.cra_priority = CRYPT_S390_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_DIGEST,
.cra_blocksize = SHA256_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct s390_sha256_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(alg.cra_list),
.cra_u = { .digest = {
.dia_digestsize = SHA256_DIGEST_SIZE,
.dia_init = sha256_init,
.dia_update = sha256_update,
.dia_final = sha256_final } }
};
static int init(void)
{
if (!crypt_s390_func_available(KIMD_SHA_256))
return -EOPNOTSUPP;
return crypto_register_alg(&alg);
}
static void __exit fini(void)
{
crypto_unregister_alg(&alg);
}
module_init(init);
module_exit(fini);
MODULE_ALIAS("sha256");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA256 Secure Hash Algorithm");