/*
* Cryptographic API.
*
* Support for VIA PadLock hardware crypto engine.
*
* Copyright (c) 2006 Michal Ludvig <michal@logix.cz>
*
* 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/sha.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/scatterlist.h>
#include <asm/i387.h>
#include "padlock.h"
#ifdef CONFIG_64BIT
#define STACK_ALIGN 16
#else
#define STACK_ALIGN 4
#endif
struct padlock_sha_desc {
struct shash_desc fallback;
};
struct padlock_sha_ctx {
struct crypto_shash *fallback;
};
static int padlock_sha_init(struct shash_desc *desc)
{
struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
struct padlock_sha_ctx *ctx = crypto_shash_ctx(desc->tfm);
dctx->fallback.tfm = ctx->fallback;
dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
return crypto_shash_init(&dctx->fallback);
}
static int padlock_sha_update(struct shash_desc *desc,
const u8 *data, unsigned int length)
{
struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
return crypto_shash_update(&dctx->fallback, data, length);
}
static inline void padlock_output_block(uint32_t *src,
uint32_t *dst, size_t count)
{
while (count--)
*dst++ = swab32(*src++);
}
static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in,
unsigned int count, u8 *out)
{
/* We can't store directly to *out as it may be unaligned. */
/* BTW Don't reduce the buffer size below 128 Bytes!
* PadLock microcode needs it that big. */
char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
((aligned(STACK_ALIGN)));
char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
struct sha1_state state;
unsigned int space;
unsigned int leftover;
int ts_state;
int err;
dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
err = crypto_shash_export(&dctx->fallback, &state);
if (err)
goto out;
if (state.count + count > ULONG_MAX)
return crypto_shash_finup(&dctx->fallback, in, count, out);
leftover = ((state.count - 1) & (SHA1_BLOCK_SIZE - 1)) + 1;
space = SHA1_BLOCK_SIZE - leftover;
if (space) {
if (count > space) {
err = crypto_shash_update(&dctx->fallback, in, space) ?:
crypto_shash_export(&dctx->fallback, &state);
if (err)
goto out;
count -= space;
in += space;
} else {
memcpy(state.buffer + leftover, in, count);
in = state.buffer;
count += leftover;
state.count &= ~(SHA1_BLOCK_SIZE - 1);
}
}
memcpy(result, &state.state, SHA1_DIGEST_SIZE);
/* prevent taking the spurious DNA fault with padlock. */
ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
: \
: "c"((unsigned long)state.count + count), \
"a"((unsigned long)state.count), \
"S"(in), "D"(result));
irq_ts_restore(ts_state);
padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
out:
return err;
}
static int padlock_sha1_final(struct shash_desc *desc, u8 *out)
{
u8 buf[4];
return padlock_sha1_finup(desc, buf, 0, out);
}
static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in,
unsigned int count, u8 *out)
{
/* We can't store directly to *out as it may be unaligned. */
/* BTW Don't reduce the buffer size below 128 Bytes!
* PadLock microcode needs it that big. */
char buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__
((aligned(STACK_ALIGN)));
char *result = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT);
struct padlock_sha_desc *dctx = shash_desc_ctx(desc);
struct sha256_state state;
unsigned int space;
unsigned int leftover;
int ts_state;
int err;
dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
err = crypto_shash_export(&dctx->fallback, &state);
if (err)
goto out;
if (state.count + count > ULONG_MAX)
return crypto_shash_finup(&dctx->fallback, in, count, out);
leftover = ((state.count - 1) & (SHA256_BLOCK_SIZE - 1)) + 1;
space = SHA256_BLOCK_SIZE - leftover;
if (space) {
if (count > space) {
err = crypto_shash_update(&dctx->fallback, in, space) ?:
crypto_shash_export(&dctx->fallback, &state);
if (err)
goto out;
count -= space;
in += space;
} else {
memcpy(state.buf + leftover, in, count);
in = state.buf;
count += leftover;
state.count &= ~(SHA1_BLOCK_SIZE - 1);
}
}
memcpy(result, &state.state, SHA256_DIGEST_SIZE);
/* prevent taking the spurious DNA fault with padlock. */
ts_state = irq_ts_save();
asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
: \
: "c"((unsigned long)state.count + count), \
"a"((unsigned long)state.count), \
"S"(in), "D"(result));
irq_ts_restore(ts_state);
padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
out:
return err;
}
static int padlock_sha256_final(struct shash_desc *desc, u8 *out)
{
u8 buf[4];
return padlock_sha256_finup(desc, buf, 0, out);
}
static int padlock_cra_init(struct crypto_tfm *tfm)
{
struct crypto_shash *hash = __crypto_shash_cast(tfm);
const char *fallback_driver_name = tfm->__crt_alg->cra_name;
struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
struct crypto_shash *fallback_tfm;
int err = -ENOMEM;
/* Allocate a fallback and abort if it failed. */
fallback_tfm = crypto_alloc_shash(fallback_driver_name, 0,
CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback_tfm)) {
printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
fallback_driver_name);
err = PTR_ERR(fallback_tfm);
goto out;
}
ctx->fallback = fallback_tfm;
hash->descsize += crypto_shash_descsize(fallback_tfm);
return 0;
out:
return err;
}
static void padlock_cra_exit(struct crypto_tfm *tfm)
{
struct padlock_sha_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_shash(ctx->fallback);
}
static struct shash_alg sha1_alg = {
.digestsize = SHA1_DIGEST_SIZE,
.init = padlock_sha_init,
.update = padlock_sha_update,
.finup = padlock_sha1_finup,
.final = padlock_sha1_final,
.descsize = sizeof(struct padlock_sha_desc),
.base = {
.cra_name = "sha1",
.cra_driver_name = "sha1-padlock",
.cra_priority = PADLOCK_CRA_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_SHASH |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = SHA1_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct padlock_sha_ctx),
.cra_module = THIS_MODULE,
.cra_init = padlock_cra_init,
.cra_exit = padlock_cra_exit,
}
};
static struct shash_alg sha256_alg = {
.digestsize = SHA256_DIGEST_SIZE,
.init = padlock_sha_init,
.update = padlock_sha_update,
.finup = padlock_sha256_finup,
.final = padlock_sha256_final,
.descsize = sizeof(struct padlock_sha_desc),
.base = {
.cra_name = "sha256",
.cra_driver_name = "sha256-padlock",
.cra_priority = PADLOCK_CRA_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_SHASH |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = SHA256_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct padlock_sha_ctx),
.cra_module = THIS_MODULE,
.cra_init = padlock_cra_init,
.cra_exit = padlock_cra_exit,
}
};
static int __init padlock_init(void)
{
int rc = -ENODEV;
if (!cpu_has_phe) {
printk(KERN_NOTICE PFX "VIA PadLock Hash Engine not detected.\n");
return -ENODEV;
}
if (!cpu_has_phe_enabled) {
printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
return -ENODEV;
}
rc = crypto_register_shash(&sha1_alg);
if (rc)
goto out;
rc = crypto_register_shash(&sha256_alg);
if (rc)
goto out_unreg1;
printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
return 0;
out_unreg1:
crypto_unregister_shash(&sha1_alg);
out:
printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
return rc;
}
static void __exit padlock_fini(void)
{
crypto_unregister_shash(&sha1_alg);
crypto_unregister_shash(&sha256_alg);
}
module_init(padlock_init);
module_exit(padlock_fini);
MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michal Ludvig");
MODULE_ALIAS("sha1-all");
MODULE_ALIAS("sha256-all");
MODULE_ALIAS("sha1-padlock");
MODULE_ALIAS("sha256-padlock");
