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linux/crypto/ccm.c
Romain Izard 441f99c904 crypto: ccm - preserve the IV buffer 
The IV buffer used during CCM operations is used twice, during both the
hashing step and the ciphering step.

When using a hardware accelerator that updates the contents of the IV
buffer at the end of ciphering operations, the value will be modified.
In the decryption case, the subsequent setup of the hashing algorithm
will interpret the updated IV instead of the original value, which can
lead to out-of-bounds writes.

Reuse the idata buffer, only used in the hashing step, to preserve the
IV's value during the ciphering step in the decryption case.

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-03 21:35:35 +08:00

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/*
* CCM: Counter with CBC-MAC
*
* (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.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/internal/aead.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include "internal.h"
struct ccm_instance_ctx {
struct crypto_skcipher_spawn ctr;
struct crypto_ahash_spawn mac;
};
struct crypto_ccm_ctx {
struct crypto_ahash *mac;
struct crypto_skcipher *ctr;
};
struct crypto_rfc4309_ctx {
struct crypto_aead *child;
u8 nonce[3];
};
struct crypto_rfc4309_req_ctx {
struct scatterlist src[3];
struct scatterlist dst[3];
struct aead_request subreq;
};
struct crypto_ccm_req_priv_ctx {
u8 odata[16];
u8 idata[16];
u8 auth_tag[16];
u32 flags;
struct scatterlist src[3];
struct scatterlist dst[3];
struct skcipher_request skreq;
};
struct cbcmac_tfm_ctx {
struct crypto_cipher *child;
};
struct cbcmac_desc_ctx {
unsigned int len;
};
static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
struct aead_request *req)
{
unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
}
static int set_msg_len(u8 *block, unsigned int msglen, int csize)
{
__be32 data;
memset(block, 0, csize);
block += csize;
if (csize >= 4)
csize = 4;
else if (msglen > (1 << (8 * csize)))
return -EOVERFLOW;
data = cpu_to_be32(msglen);
memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
return 0;
}
static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
unsigned int keylen)
{
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_skcipher *ctr = ctx->ctr;
struct crypto_ahash *mac = ctx->mac;
int err = 0;
crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
CRYPTO_TFM_REQ_MASK);
err = crypto_skcipher_setkey(ctr, key, keylen);
crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctr) &
CRYPTO_TFM_RES_MASK);
if (err)
goto out;
crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
CRYPTO_TFM_REQ_MASK);
err = crypto_ahash_setkey(mac, key, keylen);
crypto_aead_set_flags(aead, crypto_ahash_get_flags(mac) &
CRYPTO_TFM_RES_MASK);
out:
return err;
}
static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
unsigned int authsize)
{
switch (authsize) {
case 4:
case 6:
case 8:
case 10:
case 12:
case 14:
case 16:
break;
default:
return -EINVAL;
}
return 0;
}
static int format_input(u8 *info, struct aead_request *req,
unsigned int cryptlen)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
unsigned int lp = req->iv[0];
unsigned int l = lp + 1;
unsigned int m;
m = crypto_aead_authsize(aead);
memcpy(info, req->iv, 16);
/* format control info per RFC 3610 and
* NIST Special Publication 800-38C
*/
*info |= (8 * ((m - 2) / 2));
if (req->assoclen)
*info |= 64;
return set_msg_len(info + 16 - l, cryptlen, l);
}
static int format_adata(u8 *adata, unsigned int a)
{
int len = 0;
/* add control info for associated data
* RFC 3610 and NIST Special Publication 800-38C
*/
if (a < 65280) {
*(__be16 *)adata = cpu_to_be16(a);
len = 2;
} else {
*(__be16 *)adata = cpu_to_be16(0xfffe);
*(__be32 *)&adata[2] = cpu_to_be32(a);
len = 6;
}
return len;
}
static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
unsigned int cryptlen)
{
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
AHASH_REQUEST_ON_STACK(ahreq, ctx->mac);
unsigned int assoclen = req->assoclen;
struct scatterlist sg[3];
u8 *odata = pctx->odata;
u8 *idata = pctx->idata;
int ilen, err;
/* format control data for input */
err = format_input(odata, req, cryptlen);
if (err)
goto out;
sg_init_table(sg, 3);
sg_set_buf(&sg[0], odata, 16);
/* format associated data and compute into mac */
if (assoclen) {
ilen = format_adata(idata, assoclen);
sg_set_buf(&sg[1], idata, ilen);
sg_chain(sg, 3, req->src);
} else {
ilen = 0;
sg_chain(sg, 2, req->src);
}
ahash_request_set_tfm(ahreq, ctx->mac);
ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
err = crypto_ahash_init(ahreq);
if (err)
goto out;
err = crypto_ahash_update(ahreq);
if (err)
goto out;
/* we need to pad the MAC input to a round multiple of the block size */
ilen = 16 - (assoclen + ilen) % 16;
if (ilen < 16) {
memset(idata, 0, ilen);
sg_init_table(sg, 2);
sg_set_buf(&sg[0], idata, ilen);
if (plain)
sg_chain(sg, 2, plain);
plain = sg;
cryptlen += ilen;
}
ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
err = crypto_ahash_finup(ahreq);
out:
return err;
}
static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
{
struct aead_request *req = areq->data;
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
u8 *odata = pctx->odata;
if (!err)
scatterwalk_map_and_copy(odata, req->dst,
req->assoclen + req->cryptlen,
crypto_aead_authsize(aead), 1);
aead_request_complete(req, err);
}
static inline int crypto_ccm_check_iv(const u8 *iv)
{
/* 2 <= L <= 8, so 1 <= L' <= 7. */
if (1 > iv[0] || iv[0] > 7)
return -EINVAL;
return 0;
}
static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
{
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct scatterlist *sg;
u8 *iv = req->iv;
int err;
err = crypto_ccm_check_iv(iv);
if (err)
return err;
pctx->flags = aead_request_flags(req);
/* Note: rfc 3610 and NIST 800-38C require counter of
* zero to encrypt auth tag.
*/
memset(iv + 15 - iv[0], 0, iv[0] + 1);
sg_init_table(pctx->src, 3);
sg_set_buf(pctx->src, tag, 16);
sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
if (sg != pctx->src + 1)
sg_chain(pctx->src, 2, sg);
if (req->src != req->dst) {
sg_init_table(pctx->dst, 3);
sg_set_buf(pctx->dst, tag, 16);
sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
if (sg != pctx->dst + 1)
sg_chain(pctx->dst, 2, sg);
}
return 0;
}
static int crypto_ccm_encrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct skcipher_request *skreq = &pctx->skreq;
struct scatterlist *dst;
unsigned int cryptlen = req->cryptlen;
u8 *odata = pctx->odata;
u8 *iv = req->iv;
int err;
err = crypto_ccm_init_crypt(req, odata);
if (err)
return err;
err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
if (err)
return err;
dst = pctx->src;
if (req->src != req->dst)
dst = pctx->dst;
skcipher_request_set_tfm(skreq, ctx->ctr);
skcipher_request_set_callback(skreq, pctx->flags,
crypto_ccm_encrypt_done, req);
skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
err = crypto_skcipher_encrypt(skreq);
if (err)
return err;
/* copy authtag to end of dst */
scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
crypto_aead_authsize(aead), 1);
return err;
}
static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
int err)
{
struct aead_request *req = areq->data;
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct crypto_aead *aead = crypto_aead_reqtfm(req);
unsigned int authsize = crypto_aead_authsize(aead);
unsigned int cryptlen = req->cryptlen - authsize;
struct scatterlist *dst;
pctx->flags = 0;
dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
if (!err) {
err = crypto_ccm_auth(req, dst, cryptlen);
if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
err = -EBADMSG;
}
aead_request_complete(req, err);
}
static int crypto_ccm_decrypt(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
struct skcipher_request *skreq = &pctx->skreq;
struct scatterlist *dst;
unsigned int authsize = crypto_aead_authsize(aead);
unsigned int cryptlen = req->cryptlen;
u8 *authtag = pctx->auth_tag;
u8 *odata = pctx->odata;
u8 *iv = pctx->idata;
int err;
cryptlen -= authsize;
err = crypto_ccm_init_crypt(req, authtag);
if (err)
return err;
scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
authsize, 0);
dst = pctx->src;
if (req->src != req->dst)
dst = pctx->dst;
memcpy(iv, req->iv, 16);
skcipher_request_set_tfm(skreq, ctx->ctr);
skcipher_request_set_callback(skreq, pctx->flags,
crypto_ccm_decrypt_done, req);
skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
err = crypto_skcipher_decrypt(skreq);
if (err)
return err;
err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
if (err)
return err;
/* verify */
if (crypto_memneq(authtag, odata, authsize))
return -EBADMSG;
return err;
}
static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
{
struct aead_instance *inst = aead_alg_instance(tfm);
struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
struct crypto_ahash *mac;
struct crypto_skcipher *ctr;
unsigned long align;
int err;
mac = crypto_spawn_ahash(&ictx->mac);
if (IS_ERR(mac))
return PTR_ERR(mac);
ctr = crypto_spawn_skcipher(&ictx->ctr);
err = PTR_ERR(ctr);
if (IS_ERR(ctr))
goto err_free_mac;
ctx->mac = mac;
ctx->ctr = ctr;
align = crypto_aead_alignmask(tfm);
align &= ~(crypto_tfm_ctx_alignment() - 1);
crypto_aead_set_reqsize(
tfm,
align + sizeof(struct crypto_ccm_req_priv_ctx) +
crypto_skcipher_reqsize(ctr));
return 0;
err_free_mac:
crypto_free_ahash(mac);
return err;
}
static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
{
struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
crypto_free_ahash(ctx->mac);
crypto_free_skcipher(ctx->ctr);
}
static void crypto_ccm_free(struct aead_instance *inst)
{
struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
crypto_drop_ahash(&ctx->mac);
crypto_drop_skcipher(&ctx->ctr);
kfree(inst);
}
static int crypto_ccm_create_common(struct crypto_template *tmpl,
struct rtattr **tb,
const char *full_name,
const char *ctr_name,
const char *mac_name)
{
struct crypto_attr_type *algt;
struct aead_instance *inst;
struct skcipher_alg *ctr;
struct crypto_alg *mac_alg;
struct hash_alg_common *mac;
struct ccm_instance_ctx *ictx;
int err;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return PTR_ERR(algt);
if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
return -EINVAL;
mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type,
CRYPTO_ALG_TYPE_HASH,
CRYPTO_ALG_TYPE_AHASH_MASK |
CRYPTO_ALG_ASYNC);
if (IS_ERR(mac_alg))
return PTR_ERR(mac_alg);
mac = __crypto_hash_alg_common(mac_alg);
err = -EINVAL;
if (mac->digestsize != 16)
goto out_put_mac;
inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
err = -ENOMEM;
if (!inst)
goto out_put_mac;
ictx = aead_instance_ctx(inst);
err = crypto_init_ahash_spawn(&ictx->mac, mac,
aead_crypto_instance(inst));
if (err)
goto err_free_inst;
crypto_set_skcipher_spawn(&ictx->ctr, aead_crypto_instance(inst));
err = crypto_grab_skcipher(&ictx->ctr, ctr_name, 0,
crypto_requires_sync(algt->type,
algt->mask));
if (err)
goto err_drop_mac;
ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
/* Not a stream cipher? */
err = -EINVAL;
if (ctr->base.cra_blocksize != 1)
goto err_drop_ctr;
/* We want the real thing! */
if (crypto_skcipher_alg_ivsize(ctr) != 16)
goto err_drop_ctr;
err = -ENAMETOOLONG;
if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"ccm_base(%s,%s)", ctr->base.cra_driver_name,
mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto err_drop_ctr;
memcpy(inst->alg.base.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
inst->alg.base.cra_priority = (mac->base.cra_priority +
ctr->base.cra_priority) / 2;
inst->alg.base.cra_blocksize = 1;
inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
ctr->base.cra_alignmask;
inst->alg.ivsize = 16;
inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
inst->alg.maxauthsize = 16;
inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
inst->alg.init = crypto_ccm_init_tfm;
inst->alg.exit = crypto_ccm_exit_tfm;
inst->alg.setkey = crypto_ccm_setkey;
inst->alg.setauthsize = crypto_ccm_setauthsize;
inst->alg.encrypt = crypto_ccm_encrypt;
inst->alg.decrypt = crypto_ccm_decrypt;
inst->free = crypto_ccm_free;
err = aead_register_instance(tmpl, inst);
if (err)
goto err_drop_ctr;
out_put_mac:
crypto_mod_put(mac_alg);
return err;
err_drop_ctr:
crypto_drop_skcipher(&ictx->ctr);
err_drop_mac:
crypto_drop_ahash(&ictx->mac);
err_free_inst:
kfree(inst);
goto out_put_mac;
}
static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
{
const char *cipher_name;
char ctr_name[CRYPTO_MAX_ALG_NAME];
char mac_name[CRYPTO_MAX_ALG_NAME];
char full_name[CRYPTO_MAX_ALG_NAME];
cipher_name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(cipher_name))
return PTR_ERR(cipher_name);
if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
cipher_name) >= CRYPTO_MAX_ALG_NAME)
return -ENAMETOOLONG;
if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
cipher_name) >= CRYPTO_MAX_ALG_NAME)
return -ENAMETOOLONG;
if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm(%s)", cipher_name) >=
CRYPTO_MAX_ALG_NAME)
return -ENAMETOOLONG;
return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
mac_name);
}
static struct crypto_template crypto_ccm_tmpl = {
.name = "ccm",
.create = crypto_ccm_create,
.module = THIS_MODULE,
};
static int crypto_ccm_base_create(struct crypto_template *tmpl,
struct rtattr **tb)
{
const char *ctr_name;
const char *cipher_name;
char full_name[CRYPTO_MAX_ALG_NAME];
ctr_name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(ctr_name))
return PTR_ERR(ctr_name);
cipher_name = crypto_attr_alg_name(tb[2]);
if (IS_ERR(cipher_name))
return PTR_ERR(cipher_name);
if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "ccm_base(%s,%s)",
ctr_name, cipher_name) >= CRYPTO_MAX_ALG_NAME)
return -ENAMETOOLONG;
return crypto_ccm_create_common(tmpl, tb, full_name, ctr_name,
cipher_name);
}
static struct crypto_template crypto_ccm_base_tmpl = {
.name = "ccm_base",
.create = crypto_ccm_base_create,
.module = THIS_MODULE,
};
static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
unsigned int keylen)
{
struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
struct crypto_aead *child = ctx->child;
int err;
if (keylen < 3)
return -EINVAL;
keylen -= 3;
memcpy(ctx->nonce, key + keylen, 3);
crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
err = crypto_aead_setkey(child, key, keylen);
crypto_aead_set_flags(parent, crypto_aead_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}
static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
unsigned int authsize)
{
struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
switch (authsize) {
case 8:
case 12:
case 16:
break;
default:
return -EINVAL;
}
return crypto_aead_setauthsize(ctx->child, authsize);
}
static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
{
struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
struct aead_request *subreq = &rctx->subreq;
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
struct crypto_aead *child = ctx->child;
struct scatterlist *sg;
u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
crypto_aead_alignmask(child) + 1);
/* L' */
iv[0] = 3;
memcpy(iv + 1, ctx->nonce, 3);
memcpy(iv + 4, req->iv, 8);
scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
sg_init_table(rctx->src, 3);
sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
if (sg != rctx->src + 1)
sg_chain(rctx->src, 2, sg);
if (req->src != req->dst) {
sg_init_table(rctx->dst, 3);
sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
if (sg != rctx->dst + 1)
sg_chain(rctx->dst, 2, sg);
}
aead_request_set_tfm(subreq, child);
aead_request_set_callback(subreq, req->base.flags, req->base.complete,
req->base.data);
aead_request_set_crypt(subreq, rctx->src,
req->src == req->dst ? rctx->src : rctx->dst,
req->cryptlen, iv);
aead_request_set_ad(subreq, req->assoclen - 8);
return subreq;
}
static int crypto_rfc4309_encrypt(struct aead_request *req)
{
if (req->assoclen != 16 && req->assoclen != 20)
return -EINVAL;
req = crypto_rfc4309_crypt(req);
return crypto_aead_encrypt(req);
}
static int crypto_rfc4309_decrypt(struct aead_request *req)
{
if (req->assoclen != 16 && req->assoclen != 20)
return -EINVAL;
req = crypto_rfc4309_crypt(req);
return crypto_aead_decrypt(req);
}
static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
{
struct aead_instance *inst = aead_alg_instance(tfm);
struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
struct crypto_aead *aead;
unsigned long align;
aead = crypto_spawn_aead(spawn);
if (IS_ERR(aead))
return PTR_ERR(aead);
ctx->child = aead;
align = crypto_aead_alignmask(aead);
align &= ~(crypto_tfm_ctx_alignment() - 1);
crypto_aead_set_reqsize(
tfm,
sizeof(struct crypto_rfc4309_req_ctx) +
ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
align + 32);
return 0;
}
static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
{
struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
crypto_free_aead(ctx->child);
}
static void crypto_rfc4309_free(struct aead_instance *inst)
{
crypto_drop_aead(aead_instance_ctx(inst));
kfree(inst);
}
static int crypto_rfc4309_create(struct crypto_template *tmpl,
struct rtattr **tb)
{
struct crypto_attr_type *algt;
struct aead_instance *inst;
struct crypto_aead_spawn *spawn;
struct aead_alg *alg;
const char *ccm_name;
int err;
algt = crypto_get_attr_type(tb);
if (IS_ERR(algt))
return PTR_ERR(algt);
if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
return -EINVAL;
ccm_name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(ccm_name))
return PTR_ERR(ccm_name);
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return -ENOMEM;
spawn = aead_instance_ctx(inst);
crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
err = crypto_grab_aead(spawn, ccm_name, 0,
crypto_requires_sync(algt->type, algt->mask));
if (err)
goto out_free_inst;
alg = crypto_spawn_aead_alg(spawn);
err = -EINVAL;
/* We only support 16-byte blocks. */
if (crypto_aead_alg_ivsize(alg) != 16)
goto out_drop_alg;
/* Not a stream cipher? */
if (alg->base.cra_blocksize != 1)
goto out_drop_alg;
err = -ENAMETOOLONG;
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
"rfc4309(%s)", alg->base.cra_name) >=
CRYPTO_MAX_ALG_NAME ||
snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"rfc4309(%s)", alg->base.cra_driver_name) >=
CRYPTO_MAX_ALG_NAME)
goto out_drop_alg;
inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
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.ivsize = 8;
inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
inst->alg.maxauthsize = 16;
inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
inst->alg.init = crypto_rfc4309_init_tfm;
inst->alg.exit = crypto_rfc4309_exit_tfm;
inst->alg.setkey = crypto_rfc4309_setkey;
inst->alg.setauthsize = crypto_rfc4309_setauthsize;
inst->alg.encrypt = crypto_rfc4309_encrypt;
inst->alg.decrypt = crypto_rfc4309_decrypt;
inst->free = crypto_rfc4309_free;
err = aead_register_instance(tmpl, inst);
if (err)
goto out_drop_alg;
out:
return err;
out_drop_alg:
crypto_drop_aead(spawn);
out_free_inst:
kfree(inst);
goto out;
}
static struct crypto_template crypto_rfc4309_tmpl = {
.name = "rfc4309",
.create = crypto_rfc4309_create,
.module = THIS_MODULE,
};
static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
const u8 *inkey, unsigned int keylen)
{
struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
return crypto_cipher_setkey(ctx->child, inkey, keylen);
}
static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
{
struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
int bs = crypto_shash_digestsize(pdesc->tfm);
u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
ctx->len = 0;
memset(dg, 0, bs);
return 0;
}
static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
unsigned int len)
{
struct crypto_shash *parent = pdesc->tfm;
struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
struct crypto_cipher *tfm = tctx->child;
int bs = crypto_shash_digestsize(parent);
u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
while (len > 0) {
unsigned int l = min(len, bs - ctx->len);
crypto_xor(dg + ctx->len, p, l);
ctx->len +=l;
len -= l;
p += l;
if (ctx->len == bs) {
crypto_cipher_encrypt_one(tfm, dg, dg);
ctx->len = 0;
}
}
return 0;
}
static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
{
struct crypto_shash *parent = pdesc->tfm;
struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
struct crypto_cipher *tfm = tctx->child;
int bs = crypto_shash_digestsize(parent);
u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
if (ctx->len)
crypto_cipher_encrypt_one(tfm, dg, dg);
memcpy(out, dg, bs);
return 0;
}
static int cbcmac_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_cipher *cipher;
struct crypto_instance *inst = (void *)tfm->__crt_alg;
struct crypto_spawn *spawn = crypto_instance_ctx(inst);
struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
cipher = crypto_spawn_cipher(spawn);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
ctx->child = cipher;
return 0;
};
static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
{
struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_cipher(ctx->child);
}
static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct shash_instance *inst;
struct crypto_alg *alg;
int err;
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
if (err)
return err;
alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
CRYPTO_ALG_TYPE_MASK);
if (IS_ERR(alg))
return PTR_ERR(alg);
inst = shash_alloc_instance("cbcmac", alg);
err = PTR_ERR(inst);
if (IS_ERR(inst))
goto out_put_alg;
err = crypto_init_spawn(shash_instance_ctx(inst), alg,
shash_crypto_instance(inst),
CRYPTO_ALG_TYPE_MASK);
if (err)
goto out_free_inst;
inst->alg.base.cra_priority = alg->cra_priority;
inst->alg.base.cra_blocksize = 1;
inst->alg.digestsize = alg->cra_blocksize;
inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
alg->cra_alignmask + 1) +
alg->cra_blocksize;
inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
inst->alg.base.cra_init = cbcmac_init_tfm;
inst->alg.base.cra_exit = cbcmac_exit_tfm;
inst->alg.init = crypto_cbcmac_digest_init;
inst->alg.update = crypto_cbcmac_digest_update;
inst->alg.final = crypto_cbcmac_digest_final;
inst->alg.setkey = crypto_cbcmac_digest_setkey;
err = shash_register_instance(tmpl, inst);
out_free_inst:
if (err)
shash_free_instance(shash_crypto_instance(inst));
out_put_alg:
crypto_mod_put(alg);
return err;
}
static struct crypto_template crypto_cbcmac_tmpl = {
.name = "cbcmac",
.create = cbcmac_create,
.free = shash_free_instance,
.module = THIS_MODULE,
};
static int __init crypto_ccm_module_init(void)
{
int err;
err = crypto_register_template(&crypto_cbcmac_tmpl);
if (err)
goto out;
err = crypto_register_template(&crypto_ccm_base_tmpl);
if (err)
goto out_undo_cbcmac;
err = crypto_register_template(&crypto_ccm_tmpl);
if (err)
goto out_undo_base;
err = crypto_register_template(&crypto_rfc4309_tmpl);
if (err)
goto out_undo_ccm;
out:
return err;
out_undo_ccm:
crypto_unregister_template(&crypto_ccm_tmpl);
out_undo_base:
crypto_unregister_template(&crypto_ccm_base_tmpl);
out_undo_cbcmac:
crypto_register_template(&crypto_cbcmac_tmpl);
goto out;
}
static void __exit crypto_ccm_module_exit(void)
{
crypto_unregister_template(&crypto_rfc4309_tmpl);
crypto_unregister_template(&crypto_ccm_tmpl);
crypto_unregister_template(&crypto_ccm_base_tmpl);
crypto_unregister_template(&crypto_cbcmac_tmpl);
}
module_init(crypto_ccm_module_init);
module_exit(crypto_ccm_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Counter with CBC MAC");
MODULE_ALIAS_CRYPTO("ccm_base");
MODULE_ALIAS_CRYPTO("rfc4309");
MODULE_ALIAS_CRYPTO("ccm");
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