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linux/arch/s390/crypto/aes_s390.c
Sebastian Siewior f8246af005 [CRYPTO] aes: Rename aes to aes-generic
Loading the crypto algorithm by the alias instead of by module directly
has the advantage that all possible implementations of this algorithm
are loaded automatically and the crypto API can choose the best one
depending on its priority.

Additionally it ensures that the generic implementation as well as the
HW driver (if available) is loaded in case the HW driver needs the
generic version as fallback in corner cases.

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:49 -07:00

386 lines
9.1 KiB
C

/*
* Cryptographic API.
*
* s390 implementation of the AES Cipher Algorithm.
*
* s390 Version:
* Copyright IBM Corp. 2005,2007
* Author(s): Jan Glauber (jang@de.ibm.com)
*
* Derived from "crypto/aes_generic.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 <crypto/algapi.h>
#include <linux/module.h>
#include <linux/init.h>
#include "crypt_s390.h"
#define AES_MIN_KEY_SIZE 16
#define AES_MAX_KEY_SIZE 32
/* data block size for all key lengths */
#define AES_BLOCK_SIZE 16
#define AES_KEYLEN_128 1
#define AES_KEYLEN_192 2
#define AES_KEYLEN_256 4
static char keylen_flag = 0;
struct s390_aes_ctx {
u8 iv[AES_BLOCK_SIZE];
u8 key[AES_MAX_KEY_SIZE];
long enc;
long dec;
int key_len;
};
static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
u32 *flags = &tfm->crt_flags;
switch (key_len) {
case 16:
if (!(keylen_flag & AES_KEYLEN_128))
goto fail;
break;
case 24:
if (!(keylen_flag & AES_KEYLEN_192))
goto fail;
break;
case 32:
if (!(keylen_flag & AES_KEYLEN_256))
goto fail;
break;
default:
goto fail;
break;
}
sctx->key_len = key_len;
memcpy(sctx->key, in_key, key_len);
return 0;
fail:
*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
return -EINVAL;
}
static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
switch (sctx->key_len) {
case 16:
crypt_s390_km(KM_AES_128_ENCRYPT, &sctx->key, out, in,
AES_BLOCK_SIZE);
break;
case 24:
crypt_s390_km(KM_AES_192_ENCRYPT, &sctx->key, out, in,
AES_BLOCK_SIZE);
break;
case 32:
crypt_s390_km(KM_AES_256_ENCRYPT, &sctx->key, out, in,
AES_BLOCK_SIZE);
break;
}
}
static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
switch (sctx->key_len) {
case 16:
crypt_s390_km(KM_AES_128_DECRYPT, &sctx->key, out, in,
AES_BLOCK_SIZE);
break;
case 24:
crypt_s390_km(KM_AES_192_DECRYPT, &sctx->key, out, in,
AES_BLOCK_SIZE);
break;
case 32:
crypt_s390_km(KM_AES_256_DECRYPT, &sctx->key, out, in,
AES_BLOCK_SIZE);
break;
}
}
static struct crypto_alg aes_alg = {
.cra_name = "aes",
.cra_driver_name = "aes-s390",
.cra_priority = CRYPT_S390_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_CIPHER |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct s390_aes_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(aes_alg.cra_list),
.cra_u = {
.cipher = {
.cia_min_keysize = AES_MIN_KEY_SIZE,
.cia_max_keysize = AES_MAX_KEY_SIZE,
.cia_setkey = aes_set_key,
.cia_encrypt = aes_encrypt,
.cia_decrypt = aes_decrypt,
}
}
};
static int ecb_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
switch (key_len) {
case 16:
sctx->enc = KM_AES_128_ENCRYPT;
sctx->dec = KM_AES_128_DECRYPT;
break;
case 24:
sctx->enc = KM_AES_192_ENCRYPT;
sctx->dec = KM_AES_192_DECRYPT;
break;
case 32:
sctx->enc = KM_AES_256_ENCRYPT;
sctx->dec = KM_AES_256_DECRYPT;
break;
}
return aes_set_key(tfm, in_key, key_len);
}
static int ecb_aes_crypt(struct blkcipher_desc *desc, long func, void *param,
struct blkcipher_walk *walk)
{
int ret = blkcipher_walk_virt(desc, walk);
unsigned int nbytes;
while ((nbytes = walk->nbytes)) {
/* only use complete blocks */
unsigned int n = nbytes & ~(AES_BLOCK_SIZE - 1);
u8 *out = walk->dst.virt.addr;
u8 *in = walk->src.virt.addr;
ret = crypt_s390_km(func, param, out, in, n);
BUG_ON((ret < 0) || (ret != n));
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, walk, nbytes);
}
return ret;
}
static int ecb_aes_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
blkcipher_walk_init(&walk, dst, src, nbytes);
return ecb_aes_crypt(desc, sctx->enc, sctx->key, &walk);
}
static int ecb_aes_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
blkcipher_walk_init(&walk, dst, src, nbytes);
return ecb_aes_crypt(desc, sctx->dec, sctx->key, &walk);
}
static struct crypto_alg ecb_aes_alg = {
.cra_name = "ecb(aes)",
.cra_driver_name = "ecb-aes-s390",
.cra_priority = CRYPT_S390_COMPOSITE_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct s390_aes_ctx),
.cra_type = &crypto_blkcipher_type,
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(ecb_aes_alg.cra_list),
.cra_u = {
.blkcipher = {
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.setkey = ecb_aes_set_key,
.encrypt = ecb_aes_encrypt,
.decrypt = ecb_aes_decrypt,
}
}
};
static int cbc_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
switch (key_len) {
case 16:
sctx->enc = KMC_AES_128_ENCRYPT;
sctx->dec = KMC_AES_128_DECRYPT;
break;
case 24:
sctx->enc = KMC_AES_192_ENCRYPT;
sctx->dec = KMC_AES_192_DECRYPT;
break;
case 32:
sctx->enc = KMC_AES_256_ENCRYPT;
sctx->dec = KMC_AES_256_DECRYPT;
break;
}
return aes_set_key(tfm, in_key, key_len);
}
static int cbc_aes_crypt(struct blkcipher_desc *desc, long func, void *param,
struct blkcipher_walk *walk)
{
int ret = blkcipher_walk_virt(desc, walk);
unsigned int nbytes = walk->nbytes;
if (!nbytes)
goto out;
memcpy(param, walk->iv, AES_BLOCK_SIZE);
do {
/* only use complete blocks */
unsigned int n = nbytes & ~(AES_BLOCK_SIZE - 1);
u8 *out = walk->dst.virt.addr;
u8 *in = walk->src.virt.addr;
ret = crypt_s390_kmc(func, param, out, in, n);
BUG_ON((ret < 0) || (ret != n));
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, walk, nbytes);
} while ((nbytes = walk->nbytes));
memcpy(walk->iv, param, AES_BLOCK_SIZE);
out:
return ret;
}
static int cbc_aes_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
blkcipher_walk_init(&walk, dst, src, nbytes);
return cbc_aes_crypt(desc, sctx->enc, sctx->iv, &walk);
}
static int cbc_aes_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
blkcipher_walk_init(&walk, dst, src, nbytes);
return cbc_aes_crypt(desc, sctx->dec, sctx->iv, &walk);
}
static struct crypto_alg cbc_aes_alg = {
.cra_name = "cbc(aes)",
.cra_driver_name = "cbc-aes-s390",
.cra_priority = CRYPT_S390_COMPOSITE_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct s390_aes_ctx),
.cra_type = &crypto_blkcipher_type,
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(cbc_aes_alg.cra_list),
.cra_u = {
.blkcipher = {
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = cbc_aes_set_key,
.encrypt = cbc_aes_encrypt,
.decrypt = cbc_aes_decrypt,
}
}
};
static int __init aes_init(void)
{
int ret;
if (crypt_s390_func_available(KM_AES_128_ENCRYPT))
keylen_flag |= AES_KEYLEN_128;
if (crypt_s390_func_available(KM_AES_192_ENCRYPT))
keylen_flag |= AES_KEYLEN_192;
if (crypt_s390_func_available(KM_AES_256_ENCRYPT))
keylen_flag |= AES_KEYLEN_256;
if (!keylen_flag)
return -EOPNOTSUPP;
/* z9 109 and z9 BC/EC only support 128 bit key length */
if (keylen_flag == AES_KEYLEN_128) {
aes_alg.cra_u.cipher.cia_max_keysize = AES_MIN_KEY_SIZE;
ecb_aes_alg.cra_u.blkcipher.max_keysize = AES_MIN_KEY_SIZE;
cbc_aes_alg.cra_u.blkcipher.max_keysize = AES_MIN_KEY_SIZE;
printk(KERN_INFO
"aes_s390: hardware acceleration only available for"
"128 bit keys\n");
}
ret = crypto_register_alg(&aes_alg);
if (ret)
goto aes_err;
ret = crypto_register_alg(&ecb_aes_alg);
if (ret)
goto ecb_aes_err;
ret = crypto_register_alg(&cbc_aes_alg);
if (ret)
goto cbc_aes_err;
out:
return ret;
cbc_aes_err:
crypto_unregister_alg(&ecb_aes_alg);
ecb_aes_err:
crypto_unregister_alg(&aes_alg);
aes_err:
goto out;
}
static void __exit aes_fini(void)
{
crypto_unregister_alg(&cbc_aes_alg);
crypto_unregister_alg(&ecb_aes_alg);
crypto_unregister_alg(&aes_alg);
}
module_init(aes_init);
module_exit(aes_fini);
MODULE_ALIAS("aes");
MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
MODULE_LICENSE("GPL");