mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
165 lines
4.1 KiB
165 lines
4.1 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* echainiv: Encrypted Chain IV Generator |
|
* |
|
* This generator generates an IV based on a sequence number by multiplying |
|
* it with a salt and then encrypting it with the same key as used to encrypt |
|
* the plain text. This algorithm requires that the block size be equal |
|
* to the IV size. It is mainly useful for CBC. |
|
* |
|
* This generator can only be used by algorithms where authentication |
|
* is performed after encryption (i.e., authenc). |
|
* |
|
* Copyright (c) 2015 Herbert Xu <[email protected]> |
|
*/ |
|
|
|
#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 int echainiv_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); |
|
__be64 nseqno; |
|
u64 seqno; |
|
u8 *info; |
|
unsigned int ivsize = crypto_aead_ivsize(geniv); |
|
int err; |
|
|
|
if (req->cryptlen < ivsize) |
|
return -EINVAL; |
|
|
|
aead_request_set_tfm(subreq, ctx->child); |
|
|
|
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; |
|
} |
|
|
|
aead_request_set_callback(subreq, req->base.flags, |
|
req->base.complete, req->base.data); |
|
aead_request_set_crypt(subreq, req->dst, req->dst, |
|
req->cryptlen, info); |
|
aead_request_set_ad(subreq, req->assoclen); |
|
|
|
memcpy(&nseqno, info + ivsize - 8, 8); |
|
seqno = be64_to_cpu(nseqno); |
|
memset(info, 0, ivsize); |
|
|
|
scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1); |
|
|
|
do { |
|
u64 a; |
|
|
|
memcpy(&a, ctx->salt + ivsize - 8, 8); |
|
|
|
a |= 1; |
|
a *= seqno; |
|
|
|
memcpy(info + ivsize - 8, &a, 8); |
|
} while ((ivsize -= 8)); |
|
|
|
return crypto_aead_encrypt(subreq); |
|
} |
|
|
|
static int echainiv_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 = crypto_aead_ivsize(geniv); |
|
|
|
if (req->cryptlen < ivsize) |
|
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 echainiv_aead_create(struct crypto_template *tmpl, |
|
struct rtattr **tb) |
|
{ |
|
struct aead_instance *inst; |
|
int err; |
|
|
|
inst = aead_geniv_alloc(tmpl, tb); |
|
|
|
if (IS_ERR(inst)) |
|
return PTR_ERR(inst); |
|
|
|
err = -EINVAL; |
|
if (inst->alg.ivsize & (sizeof(u64) - 1) || !inst->alg.ivsize) |
|
goto free_inst; |
|
|
|
inst->alg.encrypt = echainiv_encrypt; |
|
inst->alg.decrypt = echainiv_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) { |
|
free_inst: |
|
inst->free(inst); |
|
} |
|
return err; |
|
} |
|
|
|
static struct crypto_template echainiv_tmpl = { |
|
.name = "echainiv", |
|
.create = echainiv_aead_create, |
|
.module = THIS_MODULE, |
|
}; |
|
|
|
static int __init echainiv_module_init(void) |
|
{ |
|
return crypto_register_template(&echainiv_tmpl); |
|
} |
|
|
|
static void __exit echainiv_module_exit(void) |
|
{ |
|
crypto_unregister_template(&echainiv_tmpl); |
|
} |
|
|
|
subsys_initcall(echainiv_module_init); |
|
module_exit(echainiv_module_exit); |
|
|
|
MODULE_LICENSE("GPL"); |
|
MODULE_DESCRIPTION("Encrypted Chain IV Generator"); |
|
MODULE_ALIAS_CRYPTO("echainiv");
|
|
|