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Commit 6c833275 authored by Michal Ludvig's avatar Michal Ludvig Committed by Herbert Xu
Browse files

[CRYPTO] padlock: Driver for SHA1 / SHA256 algorithms 



Support for SHA1 / SHA256 algorithms in VIA C7 processors.

Signed-off-by: default avatarMichal Ludvig <michal@logix.cz>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent ccc17c34

drivers/crypto/Kconfig

+14 −0
Original line number Diff line number Diff line
@@ -27,4 +27,18 @@ config CRYPTO_DEV_PADLOCK_AES 
	  If unsure say M. The compiled module will be

	  called padlock-aes.ko



config CRYPTO_DEV_PADLOCK_SHA

	tristate "PadLock driver for SHA1 and SHA256 algorithms"

	depends on CRYPTO_DEV_PADLOCK

	select CRYPTO_SHA1

	select CRYPTO_SHA256

	default m

	help

	  Use VIA PadLock for SHA1/SHA256 algorithms.



	  Available in VIA C7 and newer processors.



	  If unsure say M. The compiled module will be

	  called padlock-sha.ko



endmenu

drivers/crypto/Makefile

+1 −0
Original line number Diff line number Diff line 
obj-$(CONFIG_CRYPTO_DEV_PADLOCK_AES) += padlock-aes.o

obj-$(CONFIG_CRYPTO_DEV_PADLOCK_SHA) += padlock-sha.o

drivers/crypto/padlock-sha.c

0 → 100644
+339 −0
Original line number Diff line number Diff line 
/*

 * 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 <linux/module.h>

#include <linux/init.h>

#include <linux/errno.h>

#include <linux/crypto.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



static char *sha1_fallback = SHA1_DEFAULT_FALLBACK;

static char *sha256_fallback = SHA256_DEFAULT_FALLBACK;



module_param(sha1_fallback, charp, 0644);

module_param(sha256_fallback, charp, 0644);



MODULE_PARM_DESC(sha1_fallback, "Fallback driver for SHA1. Default is "

		 SHA1_DEFAULT_FALLBACK);

MODULE_PARM_DESC(sha256_fallback, "Fallback driver for SHA256. Default is "

		 SHA256_DEFAULT_FALLBACK);



struct padlock_sha_ctx {

	char		*data;

	size_t		used;

	int		bypass;

	void (*f_sha_padlock)(const char *in, char *out, int count);

	struct crypto_tfm *fallback_tfm;

};



static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)

{

	return (struct padlock_sha_ctx *)(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;



	BUG_ON(!ctx(tfm)->fallback_tfm);



	crypto_digest_init(ctx(tfm)->fallback_tfm);

	if (ctx(tfm)->data && ctx(tfm)->used) {

		struct scatterlist sg;



		sg_set_buf(&sg, ctx(tfm)->data, ctx(tfm)->used);

		crypto_digest_update(ctx(tfm)->fallback_tfm, &sg, 1);

	}



	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;

		BUG_ON(!ctx(tfm)->fallback_tfm);

		sg_set_buf(&sg, (uint8_t *)data, length);

		crypto_digest_update(ctx(tfm)->fallback_tfm, &sg, 1);

		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++);

}



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);

}



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)) {

		BUG_ON(!ctx(tfm)->fallback_tfm);

		crypto_digest_final(ctx(tfm)->fallback_tfm, 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)

{

	/* 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. */

	ctx(tfm)->fallback_tfm = crypto_alloc_tfm(fallback_driver_name, 0);

	if (!ctx(tfm)->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 -ENOENT;

	}



	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, sha1_fallback);

}



static int padlock_sha256_cra_init(struct crypto_tfm *tfm)

{

	ctx(tfm)->f_sha_padlock = padlock_do_sha256;



	return padlock_cra_init(tfm, sha256_fallback);

}



static void padlock_cra_exit(struct crypto_tfm *tfm)

{

	if (ctx(tfm)->data) {

		free_page((unsigned long)(ctx(tfm)->data));

		ctx(tfm)->data = NULL;

	}



	BUG_ON(!ctx(tfm)->fallback_tfm);

	crypto_free_tfm(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,

	.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,

	.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)

{

	static struct crypto_tfm *tfm_sha1, *tfm_sha256;



	/* We'll try to allocate one TFM for each fallback

	 * to test that the modules are available. */

	tfm_sha1 = crypto_alloc_tfm(sha1_fallback, 0);

	if (!tfm_sha1) {

		printk(KERN_WARNING PFX "Couldn't load fallback module for '%s'. Tried '%s'.\n",

		       sha1_alg.cra_name, sha1_fallback);

	} else {

		printk(KERN_NOTICE PFX "Fallback for '%s' is driver '%s' (prio=%d)\n", sha1_alg.cra_name,

		       crypto_tfm_alg_driver_name(tfm_sha1), crypto_tfm_alg_priority(tfm_sha1));

		crypto_free_tfm(tfm_sha1);

	}



	tfm_sha256 = crypto_alloc_tfm(sha256_fallback, 0);

	if (!tfm_sha256) {

		printk(KERN_WARNING PFX "Couldn't load fallback module for '%s'. Tried '%s'.\n",

		       sha256_alg.cra_name, sha256_fallback);

	} else {

		printk(KERN_NOTICE PFX "Fallback for '%s' is driver '%s' (prio=%d)\n", sha256_alg.cra_name,

		       crypto_tfm_alg_driver_name(tfm_sha256), crypto_tfm_alg_priority(tfm_sha256));

		crypto_free_tfm(tfm_sha256);

	}

}



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");