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linux/drivers/crypto/padlock-aes.c
Jeremy Katz b43e726b32 crypto: padlock - Make module loading quieter when hardware isn't available 
When loading aes or sha256 via the module aliases, the padlock modules
also try to get loaded.  Make the error message for them not being
present only be a NOTICE rather than an ERROR so that use of 'quiet'
will suppress the messages

Signed-off-by: Jeremy Katz <katzj@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-07-10 20:35:16 +08:00

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/*
* Cryptographic API.
*
* Support for VIA PadLock hardware crypto engine.
*
* Copyright (c) 2004 Michal Ludvig <michal@logix.cz>
*
*/
#include <crypto/algapi.h>
#include <crypto/aes.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <asm/byteorder.h>
#include "padlock.h"
/* Control word. */
struct cword {
unsigned int __attribute__ ((__packed__))
rounds:4,
algo:3,
keygen:1,
interm:1,
encdec:1,
ksize:2;
} __attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
/* Whenever making any changes to the following
* structure *make sure* you keep E, d_data
* and cword aligned on 16 Bytes boundaries and
* the Hardware can access 16 * 16 bytes of E and d_data
* (only the first 15 * 16 bytes matter but the HW reads
* more).
*/
struct aes_ctx {
u32 E[AES_MAX_KEYLENGTH_U32]
__attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
u32 d_data[AES_MAX_KEYLENGTH_U32]
__attribute__ ((__aligned__(PADLOCK_ALIGNMENT)));
struct {
struct cword encrypt;
struct cword decrypt;
} cword;
u32 *D;
};
/* Tells whether the ACE is capable to generate
the extended key for a given key_len. */
static inline int
aes_hw_extkey_available(uint8_t key_len)
{
/* TODO: We should check the actual CPU model/stepping
as it's possible that the capability will be
added in the next CPU revisions. */
if (key_len == 16)
return 1;
return 0;
}
static inline struct aes_ctx *aes_ctx_common(void *ctx)
{
unsigned long addr = (unsigned long)ctx;
unsigned long align = PADLOCK_ALIGNMENT;
if (align <= crypto_tfm_ctx_alignment())
align = 1;
return (struct aes_ctx *)ALIGN(addr, align);
}
static inline struct aes_ctx *aes_ctx(struct crypto_tfm *tfm)
{
return aes_ctx_common(crypto_tfm_ctx(tfm));
}
static inline struct aes_ctx *blk_aes_ctx(struct crypto_blkcipher *tfm)
{
return aes_ctx_common(crypto_blkcipher_ctx(tfm));
}
static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct aes_ctx *ctx = aes_ctx(tfm);
const __le32 *key = (const __le32 *)in_key;
u32 *flags = &tfm->crt_flags;
struct crypto_aes_ctx gen_aes;
if (key_len % 8) {
*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
return -EINVAL;
}
/*
* If the hardware is capable of generating the extended key
* itself we must supply the plain key for both encryption
* and decryption.
*/
ctx->D = ctx->E;
ctx->E[0] = le32_to_cpu(key[0]);
ctx->E[1] = le32_to_cpu(key[1]);
ctx->E[2] = le32_to_cpu(key[2]);
ctx->E[3] = le32_to_cpu(key[3]);
/* Prepare control words. */
memset(&ctx->cword, 0, sizeof(ctx->cword));
ctx->cword.decrypt.encdec = 1;
ctx->cword.encrypt.rounds = 10 + (key_len - 16) / 4;
ctx->cword.decrypt.rounds = ctx->cword.encrypt.rounds;
ctx->cword.encrypt.ksize = (key_len - 16) / 8;
ctx->cword.decrypt.ksize = ctx->cword.encrypt.ksize;
/* Don't generate extended keys if the hardware can do it. */
if (aes_hw_extkey_available(key_len))
return 0;
ctx->D = ctx->d_data;
ctx->cword.encrypt.keygen = 1;
ctx->cword.decrypt.keygen = 1;
if (crypto_aes_expand_key(&gen_aes, in_key, key_len)) {
*flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
return -EINVAL;
}
memcpy(ctx->E, gen_aes.key_enc, AES_MAX_KEYLENGTH);
memcpy(ctx->D, gen_aes.key_dec, AES_MAX_KEYLENGTH);
return 0;
}
/* ====== Encryption/decryption routines ====== */
/* These are the real call to PadLock. */
static inline void padlock_reset_key(void)
{
asm volatile ("pushfl; popfl");
}
static inline void padlock_xcrypt(const u8 *input, u8 *output, void *key,
void *control_word)
{
asm volatile (".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */
: "+S"(input), "+D"(output)
: "d"(control_word), "b"(key), "c"(1));
}
static void aes_crypt_copy(const u8 *in, u8 *out, u32 *key, struct cword *cword)
{
u8 buf[AES_BLOCK_SIZE * 2 + PADLOCK_ALIGNMENT - 1];
u8 *tmp = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
memcpy(tmp, in, AES_BLOCK_SIZE);
padlock_xcrypt(tmp, out, key, cword);
}
static inline void aes_crypt(const u8 *in, u8 *out, u32 *key,
struct cword *cword)
{
/* padlock_xcrypt requires at least two blocks of data. */
if (unlikely(!(((unsigned long)in ^ (PAGE_SIZE - AES_BLOCK_SIZE)) &
(PAGE_SIZE - 1)))) {
aes_crypt_copy(in, out, key, cword);
return;
}
padlock_xcrypt(in, out, key, cword);
}
static inline void padlock_xcrypt_ecb(const u8 *input, u8 *output, void *key,
void *control_word, u32 count)
{
if (count == 1) {
aes_crypt(input, output, key, control_word);
return;
}
asm volatile ("test $1, %%cl;"
"je 1f;"
"lea -1(%%ecx), %%eax;"
"mov $1, %%ecx;"
".byte 0xf3,0x0f,0xa7,0xc8;" /* rep xcryptecb */
"mov %%eax, %%ecx;"
"1:"
".byte 0xf3,0x0f,0xa7,0xc8" /* rep xcryptecb */
: "+S"(input), "+D"(output)
: "d"(control_word), "b"(key), "c"(count)
: "ax");
}
static inline u8 *padlock_xcrypt_cbc(const u8 *input, u8 *output, void *key,
u8 *iv, void *control_word, u32 count)
{
/* rep xcryptcbc */
asm volatile (".byte 0xf3,0x0f,0xa7,0xd0"
: "+S" (input), "+D" (output), "+a" (iv)
: "d" (control_word), "b" (key), "c" (count));
return iv;
}
static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
struct aes_ctx *ctx = aes_ctx(tfm);
padlock_reset_key();
aes_crypt(in, out, ctx->E, &ctx->cword.encrypt);
}
static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
struct aes_ctx *ctx = aes_ctx(tfm);
padlock_reset_key();
aes_crypt(in, out, ctx->D, &ctx->cword.decrypt);
}
static struct crypto_alg aes_alg = {
.cra_name = "aes",
.cra_driver_name = "aes-padlock",
.cra_priority = PADLOCK_CRA_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct aes_ctx),
.cra_alignmask = PADLOCK_ALIGNMENT - 1,
.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_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
padlock_reset_key();
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr,
ctx->E, &ctx->cword.encrypt,
nbytes / AES_BLOCK_SIZE);
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
return err;
}
static int ecb_aes_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
padlock_reset_key();
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr,
ctx->D, &ctx->cword.decrypt,
nbytes / AES_BLOCK_SIZE);
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
return err;
}
static struct crypto_alg ecb_aes_alg = {
.cra_name = "ecb(aes)",
.cra_driver_name = "ecb-aes-padlock",
.cra_priority = PADLOCK_COMPOSITE_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct aes_ctx),
.cra_alignmask = PADLOCK_ALIGNMENT - 1,
.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 = aes_set_key,
.encrypt = ecb_aes_encrypt,
.decrypt = ecb_aes_decrypt,
}
}
};
static int cbc_aes_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
padlock_reset_key();
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
u8 *iv = padlock_xcrypt_cbc(walk.src.virt.addr,
walk.dst.virt.addr, ctx->E,
walk.iv, &ctx->cword.encrypt,
nbytes / AES_BLOCK_SIZE);
memcpy(walk.iv, iv, AES_BLOCK_SIZE);
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
return err;
}
static int cbc_aes_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct aes_ctx *ctx = blk_aes_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
padlock_reset_key();
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
padlock_xcrypt_cbc(walk.src.virt.addr, walk.dst.virt.addr,
ctx->D, walk.iv, &ctx->cword.decrypt,
nbytes / AES_BLOCK_SIZE);
nbytes &= AES_BLOCK_SIZE - 1;
err = blkcipher_walk_done(desc, &walk, nbytes);
}
return err;
}
static struct crypto_alg cbc_aes_alg = {
.cra_name = "cbc(aes)",
.cra_driver_name = "cbc-aes-padlock",
.cra_priority = PADLOCK_COMPOSITE_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct aes_ctx),
.cra_alignmask = PADLOCK_ALIGNMENT - 1,
.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 = aes_set_key,
.encrypt = cbc_aes_encrypt,
.decrypt = cbc_aes_decrypt,
}
}
};
static int __init padlock_init(void)
{
int ret;
if (!cpu_has_xcrypt) {
printk(KERN_NOTICE PFX "VIA PadLock not detected.\n");
return -ENODEV;
}
if (!cpu_has_xcrypt_enabled) {
printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
return -ENODEV;
}
if ((ret = crypto_register_alg(&aes_alg)))
goto aes_err;
if ((ret = crypto_register_alg(&ecb_aes_alg)))
goto ecb_aes_err;
if ((ret = crypto_register_alg(&cbc_aes_alg)))
goto cbc_aes_err;
printk(KERN_NOTICE PFX "Using VIA PadLock ACE for AES algorithm.\n");
out:
return ret;
cbc_aes_err:
crypto_unregister_alg(&ecb_aes_alg);
ecb_aes_err:
crypto_unregister_alg(&aes_alg);
aes_err:
printk(KERN_ERR PFX "VIA PadLock AES initialization failed.\n");
goto out;
}
static void __exit padlock_fini(void)
{
crypto_unregister_alg(&cbc_aes_alg);
crypto_unregister_alg(&ecb_aes_alg);
crypto_unregister_alg(&aes_alg);
}
module_init(padlock_init);
module_exit(padlock_fini);
MODULE_DESCRIPTION("VIA PadLock AES algorithm support");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michal Ludvig");
MODULE_ALIAS("aes");
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