/*
* 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/algapi.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/cryptohash.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/scatterlist.h>
#include "padlock.h"
#define SHA1_DEFAULT_FALLBACK "sha1-generic"
#define SHA1_DIGEST_SIZE 20
#define SHA1_HMAC_BLOCK_SIZE 64
#define SHA256_DEFAULT_FALLBACK "sha256-generic"
#define SHA256_DIGEST_SIZE 32
#define SHA256_HMAC_BLOCK_SIZE 64
struct padlock_sha_ctx {
char *data;
size_t used;
int bypass;
void (*f_sha_padlock)(const char *in, char *out, int count);
struct hash_desc fallback;
};
static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
{
return crypto_tfm_ctx(tfm);
}
/* We'll need aligned address on the stack */
#define NEAREST_ALIGNED(ptr) \
((void *)ALIGN((size_t)(ptr), PADLOCK_ALIGNMENT))
static struct crypto_alg sha1_alg, sha256_alg;
static void padlock_sha_bypass(struct crypto_tfm *tfm)
{
if (ctx(tfm)->bypass)
return;
crypto_hash_init(&ctx(tfm)->fallback);
if (ctx(tfm)->data && ctx(tfm)->used) {
struct scatterlist sg;
sg_set_buf(&sg, ctx(tfm)->data, ctx(tfm)->used);
crypto_hash_update(&ctx(tfm)->fallback, &sg, sg.length);
}
ctx(tfm)->used = 0;
ctx(tfm)->bypass = 1;
}
static void padlock_sha_init(struct crypto_tfm *tfm)
{
ctx(tfm)->used = 0;
ctx(tfm)->bypass = 0;
}
static void padlock_sha_update(struct crypto_tfm *tfm,
const uint8_t *data, unsigned int length)
{
/* Our buffer is always one page. */
if (unlikely(!ctx(tfm)->bypass &&
(ctx(tfm)->used + length > PAGE_SIZE)))
padlock_sha_bypass(tfm);
if (unlikely(ctx(tfm)->bypass)) {
struct scatterlist sg;
sg_set_buf(&sg, (uint8_t *)data, length);
crypto_hash_update(&ctx(tfm)->fallback, &sg, length);
return;
}
memcpy(ctx(tfm)->data + ctx(tfm)->used, data, length);
ctx(tfm)->used += length;
}
static inline void padlock_output_block(uint32_t *src,
uint32_t *dst, size_t count)
{
while (count--)
*dst++ = swab32(*src++);
}
static void padlock_do_sha1(const char *in, char *out, int count)
{
/* 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+16];
char *result = NEAREST_ALIGNED(buf);
((uint32_t *)result)[0] = 0x67452301;
((uint32_t *)result)[1] = 0xEFCDAB89;
((uint32_t *)result)[2] = 0x98BADCFE;
((uint32_t *)result)[3] = 0x10325476;
((uint32_t *)result)[4] = 0xC3D2E1F0;
asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
: "+S"(in), "+D"(result)
: "c"(count), "a"(0));
padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
}
static void padlock_do_sha256(const char *in, char *out, int count)
{
/* 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+16];
char *result = NEAREST_ALIGNED(buf);
((uint32_t *)result)[0] = 0x6A09E667;
((uint32_t *)result)[1] = 0xBB67AE85;
((uint32_t *)result)[2] = 0x3C6EF372;
((uint32_t *)result)[3] = 0xA54FF53A;
((uint32_t *)result)[4] = 0x510E527F;
((uint32_t *)result)[5] = 0x9B05688C;
((uint32_t *)result)[6] = 0x1F83D9AB;
((uint32_t *)result)[7] = 0x5BE0CD19;
asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
: "+S"(in), "+D"(result)
: "c"(count), "a"(0));
padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
}
static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
{
if (unlikely(ctx(tfm)->bypass)) {
crypto_hash_final(&ctx(tfm)->fallback, out);
ctx(tfm)->bypass = 0;
return;
}
/* Pass the input buffer to PadLock microcode... */
ctx(tfm)->f_sha_padlock(ctx(tfm)->data, out, ctx(tfm)->used);
ctx(tfm)->used = 0;
}
static int padlock_cra_init(struct crypto_tfm *tfm)
{
const char *fallback_driver_name = tfm->__crt_alg->cra_name;
struct crypto_hash *fallback_tfm;
/* For now we'll allocate one page. This
* could eventually be configurable one day. */
ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL);
if (!ctx(tfm)->data)
return -ENOMEM;
/* Allocate a fallback and abort if it failed. */
fallback_tfm = crypto_alloc_hash(fallback_driver_name, 0,
CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback_tfm)) {
printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
fallback_driver_name);
free_page((unsigned long)(ctx(tfm)->data));
return PTR_ERR(fallback_tfm);
}
ctx(tfm)->fallback.tfm = fallback_tfm;
return 0;
}
static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
{
ctx(tfm)->f_sha_padlock = padlock_do_sha1;
return padlock_cra_init(tfm);
}
static int padlock_sha256_cra_init(struct crypto_tfm *tfm)
{
ctx(tfm)->f_sha_padlock = padlock_do_sha256;
return padlock_cra_init(tfm);
}
static void padlock_cra_exit(struct crypto_tfm *tfm)
{
if (ctx(tfm)->data) {
free_page((unsigned long)(ctx(tfm)->data));
ctx(tfm)->data = NULL;
}
crypto_free_hash(ctx(tfm)->fallback.tfm);
ctx(tfm)->fallback.tfm = NULL;
}
static struct crypto_alg sha1_alg = {
.cra_name = "sha1",
.cra_driver_name = "sha1-padlock",
.cra_priority = PADLOCK_CRA_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_DIGEST |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = SHA1_HMAC_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct padlock_sha_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(sha1_alg.cra_list),
.cra_init = padlock_sha1_cra_init,
.cra_exit = padlock_cra_exit,
.cra_u = {
.digest = {
.dia_digestsize = SHA1_DIGEST_SIZE,
.dia_init = padlock_sha_init,
.dia_update = padlock_sha_update,
.dia_final = padlock_sha_final,
}
}
};
static struct crypto_alg sha256_alg = {
.cra_name = "sha256",
.cra_driver_name = "sha256-padlock",
.cra_priority = PADLOCK_CRA_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_DIGEST |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = SHA256_HMAC_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct padlock_sha_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(sha256_alg.cra_list),
.cra_init = padlock_sha256_cra_init,
.cra_exit = padlock_cra_exit,
.cra_u = {
.digest = {
.dia_digestsize = SHA256_DIGEST_SIZE,
.dia_init = padlock_sha_init,
.dia_update = padlock_sha_update,
.dia_final = padlock_sha_final,
}
}
};
static void __init padlock_sha_check_fallbacks(void)
{
if (!crypto_has_hash("sha1", 0, CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK))
printk(KERN_WARNING PFX
"Couldn't load fallback module for sha1.\n");
if (!crypto_has_hash("sha256", 0, CRYPTO_ALG_ASYNC |
CRYPTO_ALG_NEED_FALLBACK))
printk(KERN_WARNING PFX
"Couldn't load fallback module for sha256.\n");
}
static int __init padlock_init(void)
{
int rc = -ENODEV;
if (!cpu_has_phe) {
printk(KERN_ERR PFX "VIA PadLock Hash Engine not detected.\n");
return -ENODEV;
}
if (!cpu_has_phe_enabled) {
printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
return -ENODEV;
}
padlock_sha_check_fallbacks();
rc = crypto_register_alg(&sha1_alg);
if (rc)
goto out;
rc = crypto_register_alg(&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_alg(&sha1_alg);
out:
printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
return rc;
}
static void __exit padlock_fini(void)
{
crypto_unregister_alg(&sha1_alg);
crypto_unregister_alg(&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-padlock");
MODULE_ALIAS("sha256-padlock");
