* s390 implementation of the AES Cipher Algorithm.
*
* s390 Version:
- * Copyright (C) 2005 IBM Deutschland GmbH, IBM Corporation
+ * Copyright IBM Corp. 2005,2007
* Author(s): Jan Glauber (jang@de.ibm.com)
+ * Sebastian Siewior (sebastian@breakpoint.cc> SW-Fallback
*
- * Derived from "crypto/aes.c"
+ * 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
*
*/
+#include <crypto/aes.h>
#include <crypto/algapi.h>
+#include <linux/err.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
+#define AES_KEYLEN_128 1
+#define AES_KEYLEN_192 2
+#define AES_KEYLEN_256 4
-/* data block size for all key lengths */
-#define AES_BLOCK_SIZE 16
-
-int has_aes_128 = 0;
-int has_aes_192 = 0;
-int has_aes_256 = 0;
+static char keylen_flag = 0;
struct s390_aes_ctx {
u8 iv[AES_BLOCK_SIZE];
long enc;
long dec;
int key_len;
+ union {
+ struct crypto_blkcipher *blk;
+ struct crypto_cipher *cip;
+ } fallback;
};
-static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
- unsigned int key_len)
+/*
+ * Check if the key_len is supported by the HW.
+ * Returns 0 if it is, a positive number if it is not and software fallback is
+ * required or a negative number in case the key size is not valid
+ */
+static int need_fallback(unsigned int key_len)
{
- struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
- u32 *flags = &tfm->crt_flags;
-
switch (key_len) {
case 16:
- if (!has_aes_128)
- goto fail;
+ if (!(keylen_flag & AES_KEYLEN_128))
+ return 1;
break;
case 24:
- if (!has_aes_192)
- goto fail;
-
+ if (!(keylen_flag & AES_KEYLEN_192))
+ return 1;
break;
case 32:
- if (!has_aes_256)
- goto fail;
+ if (!(keylen_flag & AES_KEYLEN_256))
+ return 1;
break;
default:
- /* invalid key length */
- goto fail;
+ return -1;
break;
}
+ return 0;
+}
+
+static int setkey_fallback_cip(struct crypto_tfm *tfm, const u8 *in_key,
+ unsigned int key_len)
+{
+ struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
+ int ret;
+
+ sctx->fallback.blk->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
+ sctx->fallback.blk->base.crt_flags |= (tfm->crt_flags &
+ CRYPTO_TFM_REQ_MASK);
+
+ ret = crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len);
+ if (ret) {
+ tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
+ tfm->crt_flags |= (sctx->fallback.blk->base.crt_flags &
+ CRYPTO_TFM_RES_MASK);
+ }
+ return ret;
+}
+
+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;
+ int ret;
+
+ ret = need_fallback(key_len);
+ if (ret < 0) {
+ *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
+ return -EINVAL;
+ }
sctx->key_len = key_len;
- memcpy(sctx->key, in_key, key_len);
- return 0;
-fail:
- *flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
- return -EINVAL;
+ if (!ret) {
+ memcpy(sctx->key, in_key, key_len);
+ return 0;
+ }
+
+ return setkey_fallback_cip(tfm, in_key, key_len);
}
static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
+ if (unlikely(need_fallback(sctx->key_len))) {
+ crypto_cipher_encrypt_one(sctx->fallback.cip, out, in);
+ return;
+ }
+
switch (sctx->key_len) {
case 16:
crypt_s390_km(KM_AES_128_ENCRYPT, &sctx->key, out, in,
{
const struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
+ if (unlikely(need_fallback(sctx->key_len))) {
+ crypto_cipher_decrypt_one(sctx->fallback.cip, out, in);
+ return;
+ }
+
switch (sctx->key_len) {
case 16:
crypt_s390_km(KM_AES_128_DECRYPT, &sctx->key, out, in,
}
}
+static int fallback_init_cip(struct crypto_tfm *tfm)
+{
+ const char *name = tfm->__crt_alg->cra_name;
+ struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
+
+ sctx->fallback.cip = crypto_alloc_cipher(name, 0,
+ CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);
+
+ if (IS_ERR(sctx->fallback.cip)) {
+ printk(KERN_ERR "Error allocating fallback algo %s\n", name);
+ return PTR_ERR(sctx->fallback.blk);
+ }
+
+ return 0;
+}
+
+static void fallback_exit_cip(struct crypto_tfm *tfm)
+{
+ struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
+
+ crypto_free_cipher(sctx->fallback.cip);
+ sctx->fallback.cip = NULL;
+}
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,
+ .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_init = fallback_init_cip,
+ .cra_exit = fallback_exit_cip,
.cra_u = {
.cipher = {
.cia_min_keysize = AES_MIN_KEY_SIZE,
}
};
+static int setkey_fallback_blk(struct crypto_tfm *tfm, const u8 *key,
+ unsigned int len)
+{
+ struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
+ unsigned int ret;
+
+ sctx->fallback.blk->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
+ sctx->fallback.blk->base.crt_flags |= (tfm->crt_flags &
+ CRYPTO_TFM_REQ_MASK);
+
+ ret = crypto_blkcipher_setkey(sctx->fallback.blk, key, len);
+ if (ret) {
+ tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
+ tfm->crt_flags |= (sctx->fallback.blk->base.crt_flags &
+ CRYPTO_TFM_RES_MASK);
+ }
+ return ret;
+}
+
+static int fallback_blk_dec(struct blkcipher_desc *desc,
+ struct scatterlist *dst, struct scatterlist *src,
+ unsigned int nbytes)
+{
+ unsigned int ret;
+ struct crypto_blkcipher *tfm;
+ struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
+
+ tfm = desc->tfm;
+ desc->tfm = sctx->fallback.blk;
+
+ ret = crypto_blkcipher_decrypt_iv(desc, dst, src, nbytes);
+
+ desc->tfm = tfm;
+ return ret;
+}
+
+static int fallback_blk_enc(struct blkcipher_desc *desc,
+ struct scatterlist *dst, struct scatterlist *src,
+ unsigned int nbytes)
+{
+ unsigned int ret;
+ struct crypto_blkcipher *tfm;
+ struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
+
+ tfm = desc->tfm;
+ desc->tfm = sctx->fallback.blk;
+
+ ret = crypto_blkcipher_encrypt_iv(desc, dst, src, nbytes);
+
+ desc->tfm = tfm;
+ return ret;
+}
+
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);
+ int ret;
+
+ ret = need_fallback(key_len);
+ if (ret > 0) {
+ sctx->key_len = key_len;
+ return setkey_fallback_blk(tfm, in_key, key_len);
+ }
switch (key_len) {
case 16:
struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
+ if (unlikely(need_fallback(sctx->key_len)))
+ return fallback_blk_enc(desc, dst, src, nbytes);
+
blkcipher_walk_init(&walk, dst, src, nbytes);
return ecb_aes_crypt(desc, sctx->enc, sctx->key, &walk);
}
struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
+ if (unlikely(need_fallback(sctx->key_len)))
+ return fallback_blk_dec(desc, dst, src, nbytes);
+
blkcipher_walk_init(&walk, dst, src, nbytes);
return ecb_aes_crypt(desc, sctx->dec, sctx->key, &walk);
}
+static int fallback_init_blk(struct crypto_tfm *tfm)
+{
+ const char *name = tfm->__crt_alg->cra_name;
+ struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
+
+ sctx->fallback.blk = crypto_alloc_blkcipher(name, 0,
+ CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);
+
+ if (IS_ERR(sctx->fallback.blk)) {
+ printk(KERN_ERR "Error allocating fallback algo %s\n", name);
+ return PTR_ERR(sctx->fallback.blk);
+ }
+
+ return 0;
+}
+
+static void fallback_exit_blk(struct crypto_tfm *tfm)
+{
+ struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
+
+ crypto_free_blkcipher(sctx->fallback.blk);
+ sctx->fallback.blk = NULL;
+}
+
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,
+ .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_init = fallback_init_blk,
+ .cra_exit = fallback_exit_blk,
.cra_u = {
.blkcipher = {
.min_keysize = AES_MIN_KEY_SIZE,
unsigned int key_len)
{
struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
+ int ret;
+
+ ret = need_fallback(key_len);
+ if (ret > 0) {
+ sctx->key_len = key_len;
+ return setkey_fallback_blk(tfm, in_key, key_len);
+ }
switch (key_len) {
case 16:
struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
+ if (unlikely(need_fallback(sctx->key_len)))
+ return fallback_blk_enc(desc, dst, src, nbytes);
+
blkcipher_walk_init(&walk, dst, src, nbytes);
return cbc_aes_crypt(desc, sctx->enc, sctx->iv, &walk);
}
struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
+ if (unlikely(need_fallback(sctx->key_len)))
+ return fallback_blk_dec(desc, dst, src, nbytes);
+
blkcipher_walk_init(&walk, dst, src, nbytes);
return cbc_aes_crypt(desc, sctx->dec, sctx->iv, &walk);
}
.cra_name = "cbc(aes)",
.cra_driver_name = "cbc-aes-s390",
.cra_priority = CRYPT_S390_COMPOSITE_PRIORITY,
- .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
+ .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_init = fallback_init_blk,
+ .cra_exit = fallback_exit_blk,
.cra_u = {
.blkcipher = {
.min_keysize = AES_MIN_KEY_SIZE,
}
};
-static int __init aes_init(void)
+static int __init aes_s390_init(void)
{
int ret;
if (crypt_s390_func_available(KM_AES_128_ENCRYPT))
- has_aes_128 = 1;
+ keylen_flag |= AES_KEYLEN_128;
if (crypt_s390_func_available(KM_AES_192_ENCRYPT))
- has_aes_192 = 1;
+ keylen_flag |= AES_KEYLEN_192;
if (crypt_s390_func_available(KM_AES_256_ENCRYPT))
- has_aes_256 = 1;
+ keylen_flag |= AES_KEYLEN_256;
+
+ if (!keylen_flag)
+ return -EOPNOTSUPP;
- if (!has_aes_128 && !has_aes_192 && !has_aes_256)
- return -ENOSYS;
+ /* z9 109 and z9 BC/EC only support 128 bit key length */
+ if (keylen_flag == AES_KEYLEN_128)
+ printk(KERN_INFO
+ "aes_s390: hardware acceleration only available for "
+ "128 bit keys\n");
ret = crypto_register_alg(&aes_alg);
- if (ret != 0) {
- printk(KERN_INFO "crypt_s390: aes-s390 couldn't be loaded.\n");
+ if (ret)
goto aes_err;
- }
ret = crypto_register_alg(&ecb_aes_alg);
- if (ret != 0) {
- printk(KERN_INFO
- "crypt_s390: ecb-aes-s390 couldn't be loaded.\n");
+ if (ret)
goto ecb_aes_err;
- }
ret = crypto_register_alg(&cbc_aes_alg);
- if (ret != 0) {
- printk(KERN_INFO
- "crypt_s390: cbc-aes-s390 couldn't be loaded.\n");
+ if (ret)
goto cbc_aes_err;
- }
out:
return ret;
goto out;
}
-static void __exit aes_fini(void)
+static void __exit aes_s390_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_init(aes_s390_init);
+module_exit(aes_s390_fini);
MODULE_ALIAS("aes");
MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
MODULE_LICENSE("GPL");
-
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