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crypto: omap-aes-gcm - use the AES library to encrypt the tag

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The OMAP AES-GCM implementation uses a fallback ecb(aes) skcipher to
produce the keystream to encrypt the output tag. Let's use the new
AES library instead - this is much simpler, and shouldn't affect
performance given that it only involves a single block.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Tero Kristo <t-kristo@ti.com>
Tested-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Ard Biesheuvel 2019-11-05 16:01:05 +02:00 committed by Herbert Xu
parent b877ad1a13
commit f0956d42c1
3 changed files with 33 additions and 98 deletions
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98
drivers/crypto/omap-aes-gcm.c
View File

@ -167,62 +167,12 @@ static int omap_aes_gcm_copy_buffers(struct omap_aes_dev *dd,
return 0;
}
static void omap_aes_gcm_complete(struct crypto_async_request *req, int err)
{
struct omap_aes_gcm_result *res = req->data;
if (err == -EINPROGRESS)
return;
res->err = err;
complete(&res->completion);
}
static int do_encrypt_iv(struct aead_request *req, u32 *tag, u32 *iv)
{
struct scatterlist iv_sg, tag_sg;
struct skcipher_request *sk_req;
struct omap_aes_gcm_result result;
struct omap_aes_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
int ret = 0;
struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
sk_req = skcipher_request_alloc(ctx->ctr, GFP_KERNEL);
if (!sk_req) {
pr_err("skcipher: Failed to allocate request\n");
return -ENOMEM;
}
init_completion(&result.completion);
sg_init_one(&iv_sg, iv, AES_BLOCK_SIZE);
sg_init_one(&tag_sg, tag, AES_BLOCK_SIZE);
skcipher_request_set_callback(sk_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
omap_aes_gcm_complete, &result);
ret = crypto_skcipher_setkey(ctx->ctr, (u8 *)ctx->key, ctx->keylen);
skcipher_request_set_crypt(sk_req, &iv_sg, &tag_sg, AES_BLOCK_SIZE,
NULL);
ret = crypto_skcipher_encrypt(sk_req);
switch (ret) {
case 0:
break;
case -EINPROGRESS:
case -EBUSY:
ret = wait_for_completion_interruptible(&result.completion);
if (!ret) {
ret = result.err;
if (!ret) {
reinit_completion(&result.completion);
break;
}
}
/* fall through */
default:
pr_err("Encryption of IV failed for GCM mode\n");
break;
}
skcipher_request_free(sk_req);
return ret;
aes_encrypt(&ctx->actx, (u8 *)tag, (u8 *)iv);
return 0;
}
void omap_aes_gcm_dma_out_callback(void *data)
@ -252,7 +202,7 @@ void omap_aes_gcm_dma_out_callback(void *data)
static int omap_aes_gcm_handle_queue(struct omap_aes_dev *dd,
struct aead_request *req)
{
struct omap_aes_ctx *ctx;
struct omap_aes_gcm_ctx *ctx;
struct aead_request *backlog;
struct omap_aes_reqctx *rctx;
unsigned long flags;
@ -281,7 +231,7 @@ static int omap_aes_gcm_handle_queue(struct omap_aes_dev *dd,
ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
rctx = aead_request_ctx(req);
dd->ctx = ctx;
dd->ctx = &ctx->octx;
rctx->dd = dd;
dd->aead_req = req;
@ -360,10 +310,10 @@ int omap_aes_gcm_decrypt(struct aead_request *req)
int omap_aes_4106gcm_encrypt(struct aead_request *req)
{
struct omap_aes_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
struct omap_aes_reqctx *rctx = aead_request_ctx(req);
memcpy(rctx->iv, ctx->nonce, 4);
memcpy(rctx->iv, ctx->octx.nonce, 4);
memcpy(rctx->iv + 4, req->iv, 8);
return crypto_ipsec_check_assoclen(req->assoclen) ?:
omap_aes_gcm_crypt(req, FLAGS_ENCRYPT | FLAGS_GCM |
@ -372,10 +322,10 @@ int omap_aes_4106gcm_encrypt(struct aead_request *req)
int omap_aes_4106gcm_decrypt(struct aead_request *req)
{
struct omap_aes_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
struct omap_aes_reqctx *rctx = aead_request_ctx(req);
memcpy(rctx->iv, ctx->nonce, 4);
memcpy(rctx->iv, ctx->octx.nonce, 4);
memcpy(rctx->iv + 4, req->iv, 8);
return crypto_ipsec_check_assoclen(req->assoclen) ?:
omap_aes_gcm_crypt(req, FLAGS_GCM | FLAGS_RFC4106_GCM);
@ -384,14 +334,15 @@ int omap_aes_4106gcm_decrypt(struct aead_request *req)
int omap_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
unsigned int keylen)
{
struct omap_aes_ctx *ctx = crypto_aead_ctx(tfm);
struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm);
int ret;
if (keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_192 &&
keylen != AES_KEYSIZE_256)
return -EINVAL;
ret = aes_expandkey(&ctx->actx, key, keylen);
if (ret)
return ret;
memcpy(ctx->key, key, keylen);
ctx->keylen = keylen;
memcpy(ctx->octx.key, key, keylen);
ctx->octx.keylen = keylen;
return 0;
}
@ -399,19 +350,20 @@ int omap_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
int omap_aes_4106gcm_setkey(struct crypto_aead *tfm, const u8 *key,
unsigned int keylen)
{
struct omap_aes_ctx *ctx = crypto_aead_ctx(tfm);
struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm);
int ret;
if (keylen < 4)
return -EINVAL;
keylen -= 4;
if (keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_192 &&
keylen != AES_KEYSIZE_256)
return -EINVAL;
memcpy(ctx->key, key, keylen);
memcpy(ctx->nonce, key + keylen, 4);
ctx->keylen = keylen;
ret = aes_expandkey(&ctx->actx, key, keylen);
if (ret)
return ret;
memcpy(ctx->octx.key, key, keylen);
memcpy(ctx->octx.nonce, key + keylen, 4);
ctx->octx.keylen = keylen;
return 0;
}

26
drivers/crypto/omap-aes.c
View File

@ -645,7 +645,6 @@ static int omap_aes_init_tfm(struct crypto_skcipher *tfm)
static int omap_aes_gcm_cra_init(struct crypto_aead *tfm)
{
struct omap_aes_dev *dd = NULL;
struct omap_aes_ctx *ctx = crypto_aead_ctx(tfm);
int err;
/* Find AES device, currently picks the first device */
@ -663,12 +662,6 @@ static int omap_aes_gcm_cra_init(struct crypto_aead *tfm)
}
tfm->reqsize = sizeof(struct omap_aes_reqctx);
ctx->ctr = crypto_alloc_skcipher("ecb(aes)", 0, 0);
if (IS_ERR(ctx->ctr)) {
pr_warn("could not load aes driver for encrypting IV\n");
return PTR_ERR(ctx->ctr);
}
return 0;
}
@ -682,19 +675,6 @@ static void omap_aes_exit_tfm(struct crypto_skcipher *tfm)
ctx->fallback = NULL;
}
static void omap_aes_gcm_cra_exit(struct crypto_aead *tfm)
{
struct omap_aes_ctx *ctx = crypto_aead_ctx(tfm);
if (ctx->fallback)
crypto_free_sync_skcipher(ctx->fallback);
ctx->fallback = NULL;
if (ctx->ctr)
crypto_free_skcipher(ctx->ctr);
}
/* ********************** ALGS ************************************ */
static struct skcipher_alg algs_ecb_cbc[] = {
@ -778,12 +758,11 @@ static struct aead_alg algs_aead_gcm[] = {
.cra_flags = CRYPTO_ALG_ASYNC |
CRYPTO_ALG_KERN_DRIVER_ONLY,
.cra_blocksize = 1,
.cra_ctxsize = sizeof(struct omap_aes_ctx),
.cra_ctxsize = sizeof(struct omap_aes_gcm_ctx),
.cra_alignmask = 0xf,
.cra_module = THIS_MODULE,
},
.init = omap_aes_gcm_cra_init,
.exit = omap_aes_gcm_cra_exit,
.ivsize = GCM_AES_IV_SIZE,
.maxauthsize = AES_BLOCK_SIZE,
.setkey = omap_aes_gcm_setkey,
@ -799,12 +778,11 @@ static struct aead_alg algs_aead_gcm[] = {
.cra_flags = CRYPTO_ALG_ASYNC |
CRYPTO_ALG_KERN_DRIVER_ONLY,
.cra_blocksize = 1,
.cra_ctxsize = sizeof(struct omap_aes_ctx),
.cra_ctxsize = sizeof(struct omap_aes_gcm_ctx),
.cra_alignmask = 0xf,
.cra_module = THIS_MODULE,
},
.init = omap_aes_gcm_cra_init,
.exit = omap_aes_gcm_cra_exit,
.maxauthsize = AES_BLOCK_SIZE,
.ivsize = GCM_RFC4106_IV_SIZE,
.setkey = omap_aes_4106gcm_setkey,

7
drivers/crypto/omap-aes.h
View File

@ -9,6 +9,7 @@
#ifndef __OMAP_AES_H__
#define __OMAP_AES_H__
#include <crypto/aes.h>
#include <crypto/engine.h>
#define DST_MAXBURST 4
@ -98,7 +99,11 @@ struct omap_aes_ctx {
u32 key[AES_KEYSIZE_256 / sizeof(u32)];
u8 nonce[4];
struct crypto_sync_skcipher *fallback;
struct crypto_skcipher *ctr;
};
struct omap_aes_gcm_ctx {
struct omap_aes_ctx octx;
struct crypto_aes_ctx actx;
};
struct omap_aes_reqctx {