The Mediatek accelerator driver calls into a dynamically allocated
skcipher of the ctr(aes) variety to perform GCM key derivation, which
involves AES encryption of a single block consisting of NUL bytes.
There is no point in using the skcipher API for this, so use the AES
library interface instead.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
drivers/crypto/Kconfig | 3 +-
drivers/crypto/mediatek/mtk-aes.c | 63 +++-----------------
2 files changed, 9 insertions(+), 57 deletions(-)
diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 802b9ada4e9e..c8c3ebb248f8 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -756,10 +756,9 @@ config CRYPTO_DEV_ZYNQMP_AES
config CRYPTO_DEV_MEDIATEK
tristate "MediaTek's EIP97 Cryptographic Engine driver"
depends on (ARM && ARCH_MEDIATEK) || COMPILE_TEST
- select CRYPTO_AES
+ select CRYPTO_LIB_AES
select CRYPTO_AEAD
select CRYPTO_SKCIPHER
- select CRYPTO_CTR
select CRYPTO_SHA1
select CRYPTO_SHA256
select CRYPTO_SHA512
diff --git a/drivers/crypto/mediatek/mtk-aes.c b/drivers/crypto/mediatek/mtk-aes.c
index 78d660d963e2..4ad3571ab6af 100644
--- a/drivers/crypto/mediatek/mtk-aes.c
+++ b/drivers/crypto/mediatek/mtk-aes.c
@@ -137,8 +137,6 @@ struct mtk_aes_gcm_ctx {
u32 authsize;
size_t textlen;
-
- struct crypto_skcipher *ctr;
};
struct mtk_aes_drv {
@@ -996,17 +994,8 @@ static int mtk_aes_gcm_setkey(struct crypto_aead *aead, const u8 *key,
u32 keylen)
{
struct mtk_aes_base_ctx *ctx = crypto_aead_ctx(aead);
- struct mtk_aes_gcm_ctx *gctx = mtk_aes_gcm_ctx_cast(ctx);
- struct crypto_skcipher *ctr = gctx->ctr;
- struct {
- u32 hash[4];
- u8 iv[8];
-
- struct crypto_wait wait;
-
- struct scatterlist sg[1];
- struct skcipher_request req;
- } *data;
+ u8 hash[AES_BLOCK_SIZE] __aligned(4) = {};
+ struct crypto_aes_ctx aes_ctx;
int err;
switch (keylen) {
@@ -1026,39 +1015,18 @@ static int mtk_aes_gcm_setkey(struct crypto_aead *aead, const u8 *key,
ctx->keylen = SIZE_IN_WORDS(keylen);
- /* Same as crypto_gcm_setkey() from crypto/gcm.c */
- 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);
+ err = aes_expandkey(&aes_ctx, key, keylen);
if (err)
return err;
- data = kzalloc(sizeof(*data) + crypto_skcipher_reqsize(ctr),
- GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
- crypto_init_wait(&data->wait);
- sg_init_one(data->sg, &data->hash, AES_BLOCK_SIZE);
- skcipher_request_set_tfm(&data->req, ctr);
- skcipher_request_set_callback(&data->req, CRYPTO_TFM_REQ_MAY_SLEEP |
- CRYPTO_TFM_REQ_MAY_BACKLOG,
- crypto_req_done, &data->wait);
- skcipher_request_set_crypt(&data->req, data->sg, data->sg,
- AES_BLOCK_SIZE, data->iv);
-
- err = crypto_wait_req(crypto_skcipher_encrypt(&data->req),
- &data->wait);
- if (err)
- goto out;
+ aes_encrypt(&aes_ctx, hash, hash);
+ memzero_explicit(&aes_ctx, sizeof(aes_ctx));
mtk_aes_write_state_le(ctx->key, (const u32 *)key, keylen);
- mtk_aes_write_state_be(ctx->key + ctx->keylen, data->hash,
+ mtk_aes_write_state_be(ctx->key + ctx->keylen, (const u32 *)hash,
AES_BLOCK_SIZE);
-out:
- kzfree(data);
- return err;
+
+ return 0;
}
static int mtk_aes_gcm_setauthsize(struct crypto_aead *aead,
@@ -1095,32 +1063,17 @@ static int mtk_aes_gcm_init(struct crypto_aead *aead)
{
struct mtk_aes_gcm_ctx *ctx = crypto_aead_ctx(aead);
- ctx->ctr = crypto_alloc_skcipher("ctr(aes)", 0,
- CRYPTO_ALG_ASYNC);
- if (IS_ERR(ctx->ctr)) {
- pr_err("Error allocating ctr(aes)\n");
- return PTR_ERR(ctx->ctr);
- }
-
crypto_aead_set_reqsize(aead, sizeof(struct mtk_aes_reqctx));
ctx->base.start = mtk_aes_gcm_start;
return 0;
}
-static void mtk_aes_gcm_exit(struct crypto_aead *aead)
-{
- struct mtk_aes_gcm_ctx *ctx = crypto_aead_ctx(aead);
-
- crypto_free_skcipher(ctx->ctr);
-}
-
static struct aead_alg aes_gcm_alg = {
.setkey = mtk_aes_gcm_setkey,
.setauthsize = mtk_aes_gcm_setauthsize,
.encrypt = mtk_aes_gcm_encrypt,
.decrypt = mtk_aes_gcm_decrypt,
.init = mtk_aes_gcm_init,
- .exit = mtk_aes_gcm_exit,
.ivsize = GCM_AES_IV_SIZE,
.maxauthsize = AES_BLOCK_SIZE,
--
2.27.0
