linux/crypto/seqiv.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

215 lines
5.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* seqiv: Sequence Number IV Generator
*
* This generator generates an IV based on a sequence number by xoring it
* with a salt. This algorithm is mainly useful for CTR and similar modes.
*
* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <crypto/internal/geniv.h>
#include <crypto/scatterwalk.h>
#include <crypto/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
static void seqiv_free(struct crypto_instance *inst);
static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err)
{
struct aead_request *subreq = aead_request_ctx(req);
struct crypto_aead *geniv;
if (err == -EINPROGRESS)
return;
if (err)
goto out;
geniv = crypto_aead_reqtfm(req);
memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv));
out:
kzfree(subreq->iv);
}
static void seqiv_aead_encrypt_complete(struct crypto_async_request *base,
int err)
{
struct aead_request *req = base->data;
seqiv_aead_encrypt_complete2(req, err);
aead_request_complete(req, err);
}
static int seqiv_aead_encrypt(struct aead_request *req)
{
struct crypto_aead *geniv = crypto_aead_reqtfm(req);
struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
struct aead_request *subreq = aead_request_ctx(req);
crypto_completion_t compl;
void *data;
u8 *info;
unsigned int ivsize = 8;
int err;
if (req->cryptlen < ivsize)
return -EINVAL;
aead_request_set_tfm(subreq, ctx->child);
compl = req->base.complete;
data = req->base.data;
info = req->iv;
if (req->src != req->dst) {
SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->sknull);
skcipher_request_set_sync_tfm(nreq, ctx->sknull);
skcipher_request_set_callback(nreq, req->base.flags,
NULL, NULL);
skcipher_request_set_crypt(nreq, req->src, req->dst,
req->assoclen + req->cryptlen,
NULL);
err = crypto_skcipher_encrypt(nreq);
if (err)
return err;
}
if (unlikely(!IS_ALIGNED((unsigned long)info,
crypto_aead_alignmask(geniv) + 1))) {
info = kmemdup(req->iv, ivsize, req->base.flags &
CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL :
GFP_ATOMIC);
if (!info)
return -ENOMEM;
compl = seqiv_aead_encrypt_complete;
data = req;
}
aead_request_set_callback(subreq, req->base.flags, compl, data);
aead_request_set_crypt(subreq, req->dst, req->dst,
req->cryptlen - ivsize, info);
aead_request_set_ad(subreq, req->assoclen + ivsize);
crypto_xor(info, ctx->salt, ivsize);
scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
err = crypto_aead_encrypt(subreq);
if (unlikely(info != req->iv))
seqiv_aead_encrypt_complete2(req, err);
return err;
}
static int seqiv_aead_decrypt(struct aead_request *req)
{
struct crypto_aead *geniv = crypto_aead_reqtfm(req);
struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
struct aead_request *subreq = aead_request_ctx(req);
crypto_completion_t compl;
void *data;
unsigned int ivsize = 8;
if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
return -EINVAL;
aead_request_set_tfm(subreq, ctx->child);
compl = req->base.complete;
data = req->base.data;
aead_request_set_callback(subreq, req->base.flags, compl, data);
aead_request_set_crypt(subreq, req->src, req->dst,
req->cryptlen - ivsize, req->iv);
aead_request_set_ad(subreq, req->assoclen + ivsize);
scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
return crypto_aead_decrypt(subreq);
}
static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct aead_instance *inst;
int err;
inst = aead_geniv_alloc(tmpl, tb, 0, 0);
if (IS_ERR(inst))
return PTR_ERR(inst);
err = -EINVAL;
if (inst->alg.ivsize != sizeof(u64))
goto free_inst;
inst->alg.encrypt = seqiv_aead_encrypt;
inst->alg.decrypt = seqiv_aead_decrypt;
inst->alg.init = aead_init_geniv;
inst->alg.exit = aead_exit_geniv;
inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
inst->alg.base.cra_ctxsize += inst->alg.ivsize;
err = aead_register_instance(tmpl, inst);
if (err)
goto free_inst;
out:
return err;
free_inst:
aead_geniv_free(inst);
goto out;
}
static int seqiv_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct crypto_attr_type *algt;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return PTR_ERR(algt);
if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
return -EINVAL;
return seqiv_aead_create(tmpl, tb);
}
static void seqiv_free(struct crypto_instance *inst)
{
aead_geniv_free(aead_instance(inst));
}
static struct crypto_template seqiv_tmpl = {
.name = "seqiv",
.create = seqiv_create,
.free = seqiv_free,
.module = THIS_MODULE,
};
static int __init seqiv_module_init(void)
{
return crypto_register_template(&seqiv_tmpl);
}
static void __exit seqiv_module_exit(void)
{
crypto_unregister_template(&seqiv_tmpl);
}
subsys_initcall(seqiv_module_init);
module_exit(seqiv_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Sequence Number IV Generator");
MODULE_ALIAS_CRYPTO("seqiv");