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linux-next/crypto/ctr.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

389 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* CTR: Counter mode
*
* (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
*/
#include <crypto/algapi.h>
#include <crypto/ctr.h>
#include <crypto/internal/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
struct crypto_rfc3686_ctx {
struct crypto_skcipher *child;
u8 nonce[CTR_RFC3686_NONCE_SIZE];
};
struct crypto_rfc3686_req_ctx {
u8 iv[CTR_RFC3686_BLOCK_SIZE];
struct skcipher_request subreq CRYPTO_MINALIGN_ATTR;
};
static void crypto_ctr_crypt_final(struct skcipher_walk *walk,
struct crypto_cipher *tfm)
{
unsigned int bsize = crypto_cipher_blocksize(tfm);
unsigned long alignmask = crypto_cipher_alignmask(tfm);
u8 *ctrblk = walk->iv;
u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
unsigned int nbytes = walk->nbytes;
crypto_cipher_encrypt_one(tfm, keystream, ctrblk);
crypto_xor_cpy(dst, keystream, src, nbytes);
crypto_inc(ctrblk, bsize);
}
static int crypto_ctr_crypt_segment(struct skcipher_walk *walk,
struct crypto_cipher *tfm)
{
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
crypto_cipher_alg(tfm)->cia_encrypt;
unsigned int bsize = crypto_cipher_blocksize(tfm);
u8 *ctrblk = walk->iv;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
unsigned int nbytes = walk->nbytes;
do {
/* create keystream */
fn(crypto_cipher_tfm(tfm), dst, ctrblk);
crypto_xor(dst, src, bsize);
/* increment counter in counterblock */
crypto_inc(ctrblk, bsize);
src += bsize;
dst += bsize;
} while ((nbytes -= bsize) >= bsize);
return nbytes;
}
static int crypto_ctr_crypt_inplace(struct skcipher_walk *walk,
struct crypto_cipher *tfm)
{
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
crypto_cipher_alg(tfm)->cia_encrypt;
unsigned int bsize = crypto_cipher_blocksize(tfm);
unsigned long alignmask = crypto_cipher_alignmask(tfm);
unsigned int nbytes = walk->nbytes;
u8 *ctrblk = walk->iv;
u8 *src = walk->src.virt.addr;
u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
do {
/* create keystream */
fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
crypto_xor(src, keystream, bsize);
/* increment counter in counterblock */
crypto_inc(ctrblk, bsize);
src += bsize;
} while ((nbytes -= bsize) >= bsize);
return nbytes;
}
static int crypto_ctr_crypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
const unsigned int bsize = crypto_cipher_blocksize(cipher);
struct skcipher_walk walk;
unsigned int nbytes;
int err;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes >= bsize) {
if (walk.src.virt.addr == walk.dst.virt.addr)
nbytes = crypto_ctr_crypt_inplace(&walk, cipher);
else
nbytes = crypto_ctr_crypt_segment(&walk, cipher);
err = skcipher_walk_done(&walk, nbytes);
}
if (walk.nbytes) {
crypto_ctr_crypt_final(&walk, cipher);
err = skcipher_walk_done(&walk, 0);
}
return err;
}
static int crypto_ctr_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct skcipher_instance *inst;
struct crypto_alg *alg;
int err;
inst = skcipher_alloc_instance_simple(tmpl, tb, &alg);
if (IS_ERR(inst))
return PTR_ERR(inst);
/* Block size must be >= 4 bytes. */
err = -EINVAL;
if (alg->cra_blocksize < 4)
goto out_free_inst;
/* If this is false we'd fail the alignment of crypto_inc. */
if (alg->cra_blocksize % 4)
goto out_free_inst;
/* CTR mode is a stream cipher. */
inst->alg.base.cra_blocksize = 1;
/*
* To simplify the implementation, configure the skcipher walk to only
* give a partial block at the very end, never earlier.
*/
inst->alg.chunksize = alg->cra_blocksize;
inst->alg.encrypt = crypto_ctr_crypt;
inst->alg.decrypt = crypto_ctr_crypt;
err = skcipher_register_instance(tmpl, inst);
if (err)
goto out_free_inst;
goto out_put_alg;
out_free_inst:
inst->free(inst);
out_put_alg:
crypto_mod_put(alg);
return err;
}
static int crypto_rfc3686_setkey(struct crypto_skcipher *parent,
const u8 *key, unsigned int keylen)
{
struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
struct crypto_skcipher *child = ctx->child;
int err;
/* the nonce is stored in bytes at end of key */
if (keylen < CTR_RFC3686_NONCE_SIZE)
return -EINVAL;
memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
CTR_RFC3686_NONCE_SIZE);
keylen -= CTR_RFC3686_NONCE_SIZE;
crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_skcipher_setkey(child, key, keylen);
crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}
static int crypto_rfc3686_crypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *child = ctx->child;
unsigned long align = crypto_skcipher_alignmask(tfm);
struct crypto_rfc3686_req_ctx *rctx =
(void *)PTR_ALIGN((u8 *)skcipher_request_ctx(req), align + 1);
struct skcipher_request *subreq = &rctx->subreq;
u8 *iv = rctx->iv;
/* set up counter block */
memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
/* initialize counter portion of counter block */
*(__be32 *)(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
cpu_to_be32(1);
skcipher_request_set_tfm(subreq, child);
skcipher_request_set_callback(subreq, req->base.flags,
req->base.complete, req->base.data);
skcipher_request_set_crypt(subreq, req->src, req->dst,
req->cryptlen, iv);
return crypto_skcipher_encrypt(subreq);
}
static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm)
{
struct skcipher_instance *inst = skcipher_alg_instance(tfm);
struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_skcipher *cipher;
unsigned long align;
unsigned int reqsize;
cipher = crypto_spawn_skcipher(spawn);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
ctx->child = cipher;
align = crypto_skcipher_alignmask(tfm);
align &= ~(crypto_tfm_ctx_alignment() - 1);
reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) +
crypto_skcipher_reqsize(cipher);
crypto_skcipher_set_reqsize(tfm, reqsize);
return 0;
}
static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm)
{
struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
crypto_free_skcipher(ctx->child);
}
static void crypto_rfc3686_free(struct skcipher_instance *inst)
{
struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
crypto_drop_skcipher(spawn);
kfree(inst);
}
static int crypto_rfc3686_create(struct crypto_template *tmpl,
struct rtattr **tb)
{
struct crypto_attr_type *algt;
struct skcipher_instance *inst;
struct skcipher_alg *alg;
struct crypto_skcipher_spawn *spawn;
const char *cipher_name;
u32 mask;
int err;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return PTR_ERR(algt);
if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
return -EINVAL;
cipher_name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(cipher_name))
return PTR_ERR(cipher_name);
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return -ENOMEM;
mask = crypto_requires_sync(algt->type, algt->mask) |
crypto_requires_off(algt->type, algt->mask,
CRYPTO_ALG_NEED_FALLBACK);
spawn = skcipher_instance_ctx(inst);
crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
err = crypto_grab_skcipher(spawn, cipher_name, 0, mask);
if (err)
goto err_free_inst;
alg = crypto_spawn_skcipher_alg(spawn);
/* We only support 16-byte blocks. */
err = -EINVAL;
if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
goto err_drop_spawn;
/* Not a stream cipher? */
if (alg->base.cra_blocksize != 1)
goto err_drop_spawn;
err = -ENAMETOOLONG;
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
"rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
goto err_drop_spawn;
if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"rfc3686(%s)", alg->base.cra_driver_name) >=
CRYPTO_MAX_ALG_NAME)
goto err_drop_spawn;
inst->alg.base.cra_priority = alg->base.cra_priority;
inst->alg.base.cra_blocksize = 1;
inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
CTR_RFC3686_NONCE_SIZE;
inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
CTR_RFC3686_NONCE_SIZE;
inst->alg.setkey = crypto_rfc3686_setkey;
inst->alg.encrypt = crypto_rfc3686_crypt;
inst->alg.decrypt = crypto_rfc3686_crypt;
inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
inst->alg.init = crypto_rfc3686_init_tfm;
inst->alg.exit = crypto_rfc3686_exit_tfm;
inst->free = crypto_rfc3686_free;
err = skcipher_register_instance(tmpl, inst);
if (err)
goto err_drop_spawn;
out:
return err;
err_drop_spawn:
crypto_drop_skcipher(spawn);
err_free_inst:
kfree(inst);
goto out;
}
static struct crypto_template crypto_ctr_tmpls[] = {
{
.name = "ctr",
.create = crypto_ctr_create,
.module = THIS_MODULE,
}, {
.name = "rfc3686",
.create = crypto_rfc3686_create,
.module = THIS_MODULE,
},
};
static int __init crypto_ctr_module_init(void)
{
return crypto_register_templates(crypto_ctr_tmpls,
ARRAY_SIZE(crypto_ctr_tmpls));
}
static void __exit crypto_ctr_module_exit(void)
{
crypto_unregister_templates(crypto_ctr_tmpls,
ARRAY_SIZE(crypto_ctr_tmpls));
}
subsys_initcall(crypto_ctr_module_init);
module_exit(crypto_ctr_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("CTR block cipher mode of operation");
MODULE_ALIAS_CRYPTO("rfc3686");
MODULE_ALIAS_CRYPTO("ctr");