linux/arch/x86/crypto/fpu.c

168 lines
4.5 KiB
C

/*
* FPU: Wrapper for blkcipher touching fpu
*
* Copyright (c) Intel Corp.
* Author: Huang Ying <ying.huang@intel.com>
*
* 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/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <asm/i387.h>
struct crypto_fpu_ctx {
struct crypto_blkcipher *child;
};
static int crypto_fpu_setkey(struct crypto_tfm *parent, const u8 *key,
unsigned int keylen)
{
struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(parent);
struct crypto_blkcipher *child = ctx->child;
int err;
crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_blkcipher_set_flags(child, crypto_tfm_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_blkcipher_setkey(child, key, keylen);
crypto_tfm_set_flags(parent, crypto_blkcipher_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}
static int crypto_fpu_encrypt(struct blkcipher_desc *desc_in,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
int err;
struct crypto_fpu_ctx *ctx = crypto_blkcipher_ctx(desc_in->tfm);
struct crypto_blkcipher *child = ctx->child;
struct blkcipher_desc desc = {
.tfm = child,
.info = desc_in->info,
.flags = desc_in->flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
};
kernel_fpu_begin();
err = crypto_blkcipher_crt(desc.tfm)->encrypt(&desc, dst, src, nbytes);
kernel_fpu_end();
return err;
}
static int crypto_fpu_decrypt(struct blkcipher_desc *desc_in,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
int err;
struct crypto_fpu_ctx *ctx = crypto_blkcipher_ctx(desc_in->tfm);
struct crypto_blkcipher *child = ctx->child;
struct blkcipher_desc desc = {
.tfm = child,
.info = desc_in->info,
.flags = desc_in->flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
};
kernel_fpu_begin();
err = crypto_blkcipher_crt(desc.tfm)->decrypt(&desc, dst, src, nbytes);
kernel_fpu_end();
return err;
}
static int crypto_fpu_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
struct crypto_spawn *spawn = crypto_instance_ctx(inst);
struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(tfm);
struct crypto_blkcipher *cipher;
cipher = crypto_spawn_blkcipher(spawn);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
ctx->child = cipher;
return 0;
}
static void crypto_fpu_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_blkcipher(ctx->child);
}
static struct crypto_instance *crypto_fpu_alloc(struct rtattr **tb)
{
struct crypto_instance *inst;
struct crypto_alg *alg;
int err;
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
if (err)
return ERR_PTR(err);
alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
CRYPTO_ALG_TYPE_MASK);
if (IS_ERR(alg))
return ERR_CAST(alg);
inst = crypto_alloc_instance("fpu", alg);
if (IS_ERR(inst))
goto out_put_alg;
inst->alg.cra_flags = alg->cra_flags;
inst->alg.cra_priority = alg->cra_priority;
inst->alg.cra_blocksize = alg->cra_blocksize;
inst->alg.cra_alignmask = alg->cra_alignmask;
inst->alg.cra_type = alg->cra_type;
inst->alg.cra_blkcipher.ivsize = alg->cra_blkcipher.ivsize;
inst->alg.cra_blkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
inst->alg.cra_blkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
inst->alg.cra_ctxsize = sizeof(struct crypto_fpu_ctx);
inst->alg.cra_init = crypto_fpu_init_tfm;
inst->alg.cra_exit = crypto_fpu_exit_tfm;
inst->alg.cra_blkcipher.setkey = crypto_fpu_setkey;
inst->alg.cra_blkcipher.encrypt = crypto_fpu_encrypt;
inst->alg.cra_blkcipher.decrypt = crypto_fpu_decrypt;
out_put_alg:
crypto_mod_put(alg);
return inst;
}
static void crypto_fpu_free(struct crypto_instance *inst)
{
crypto_drop_spawn(crypto_instance_ctx(inst));
kfree(inst);
}
static struct crypto_template crypto_fpu_tmpl = {
.name = "fpu",
.alloc = crypto_fpu_alloc,
.free = crypto_fpu_free,
.module = THIS_MODULE,
};
static int __init crypto_fpu_module_init(void)
{
return crypto_register_template(&crypto_fpu_tmpl);
}
static void __exit crypto_fpu_module_exit(void)
{
crypto_unregister_template(&crypto_fpu_tmpl);
}
module_init(crypto_fpu_module_init);
module_exit(crypto_fpu_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("FPU block cipher wrapper");