[PATCH 7/8] crypto: mediatek - add support to CTR mode
Ryder Lee
ryder.lee at mediatek.com
Thu Jan 19 21:41:14 PST 2017
This patch adds support to the CTR mode.
Signed-off-by: Ryder Lee <ryder.lee at mediatek.com>
---
drivers/crypto/mediatek/mtk-aes.c | 151 ++++++++++++++++++++++++++++++++++++--
1 file changed, 146 insertions(+), 5 deletions(-)
diff --git a/drivers/crypto/mediatek/mtk-aes.c b/drivers/crypto/mediatek/mtk-aes.c
index 5e7c3ce..bb5b4ff 100644
--- a/drivers/crypto/mediatek/mtk-aes.c
+++ b/drivers/crypto/mediatek/mtk-aes.c
@@ -23,8 +23,10 @@
/* AES command token size */
#define AES_CT_SIZE_ECB 2
#define AES_CT_SIZE_CBC 3
+#define AES_CT_SIZE_CTR 3
#define AES_CT_CTRL_HDR cpu_to_le32(0x00220000)
-/* AES-CBC/ECB command token */
+
+/* AES-CBC/ECB/CTR command token */
#define AES_CMD0 cpu_to_le32(0x05000000)
#define AES_CMD1 cpu_to_le32(0x2d060000)
#define AES_CMD2 cpu_to_le32(0xe4a63806)
@@ -39,13 +41,15 @@
/* AES transform information word 1 fields */
#define AES_TFM_ECB cpu_to_le32(0x0 << 0)
#define AES_TFM_CBC cpu_to_le32(0x1 << 0)
-#define AES_TFM_FULL_IV cpu_to_le32(0xf << 5)
+#define AES_TFM_CTR_LOAD cpu_to_le32(0x6 << 0) /* load/reuse counter */
+#define AES_TFM_FULL_IV cpu_to_le32(0xf << 5) /* using IV 0-3 */
/* AES flags */
#define AES_FLAGS_ECB BIT(0)
#define AES_FLAGS_CBC BIT(1)
-#define AES_FLAGS_ENCRYPT BIT(2)
-#define AES_FLAGS_BUSY BIT(3)
+#define AES_FLAGS_CTR BIT(2)
+#define AES_FLAGS_ENCRYPT BIT(3)
+#define AES_FLAGS_BUSY BIT(4)
/**
* Command token(CT) is a set of hardware instructions that
@@ -90,6 +94,15 @@ struct mtk_aes_ctx {
struct mtk_aes_base_ctx base;
};
+struct mtk_aes_ctr_ctx {
+ struct mtk_aes_base_ctx base;
+
+ u32 iv[AES_BLOCK_SIZE / sizeof(u32)];
+ size_t offset;
+ struct scatterlist src[2];
+ struct scatterlist dst[2];
+};
+
struct mtk_aes_drv {
struct list_head dev_list;
/* Device list lock */
@@ -332,7 +345,7 @@ static int mtk_aes_map(struct mtk_cryp *cryp, struct mtk_aes_rec *aes)
return -EINVAL;
}
-/* Initialize transform information of CBC/ECB mode */
+/* Initialize transform information of CBC/ECB/CTR mode */
static void mtk_aes_info_init(struct mtk_cryp *cryp, struct mtk_aes_rec *aes,
size_t len)
{
@@ -374,6 +387,13 @@ static void mtk_aes_info_init(struct mtk_cryp *cryp, struct mtk_aes_rec *aes,
ctx->tfm.ctrl[1] = AES_TFM_ECB;
ctx->ct_size = AES_CT_SIZE_ECB;
+ } else if (aes->flags & AES_FLAGS_CTR) {
+ ctx->tfm.ctrl[0] |= AES_TFM_SIZE(ctx->keylen +
+ SIZE_IN_WORDS(AES_BLOCK_SIZE));
+ ctx->tfm.ctrl[1] = AES_TFM_CTR_LOAD | AES_TFM_FULL_IV;
+
+ ctx->ct.cmd[2] = AES_CMD2;
+ ctx->ct_size = AES_CT_SIZE_CTR;
}
}
@@ -479,6 +499,80 @@ static int mtk_aes_start(struct mtk_cryp *cryp, struct mtk_aes_rec *aes)
return mtk_aes_dma(cryp, aes, req->src, req->dst, req->nbytes);
}
+static inline struct mtk_aes_ctr_ctx *
+mtk_aes_ctr_ctx_cast(struct mtk_aes_base_ctx *ctx)
+{
+ return container_of(ctx, struct mtk_aes_ctr_ctx, base);
+}
+
+static int mtk_aes_ctr_transfer(struct mtk_cryp *cryp, struct mtk_aes_rec *aes)
+{
+ struct mtk_aes_base_ctx *ctx = aes->ctx;
+ struct mtk_aes_ctr_ctx *cctx = mtk_aes_ctr_ctx_cast(ctx);
+ struct ablkcipher_request *req = ablkcipher_request_cast(aes->areq);
+ struct scatterlist *src, *dst;
+ int i;
+ u32 start, end, ctr, blocks, *iv_state;
+ size_t datalen;
+ bool fragmented = false;
+
+ /* Check for transfer completion. */
+ cctx->offset += aes->total;
+ if (cctx->offset >= req->nbytes)
+ return mtk_aes_complete(cryp, aes);
+
+ /* Compute data length. */
+ datalen = req->nbytes - cctx->offset;
+ blocks = DIV_ROUND_UP(datalen, AES_BLOCK_SIZE);
+ ctr = be32_to_cpu(cctx->iv[3]);
+
+ /* Check 32bit counter overflow. */
+ start = ctr;
+ end = start + blocks - 1;
+ if (end < start) {
+ ctr |= 0xffffffff;
+ datalen = AES_BLOCK_SIZE * -start;
+ fragmented = true;
+ }
+
+ /* Jump to offset. */
+ src = scatterwalk_ffwd(cctx->src, req->src, cctx->offset);
+ dst = ((req->src == req->dst) ? src :
+ scatterwalk_ffwd(cctx->dst, req->dst, cctx->offset));
+
+ /* Write IVs into transform state buffer. */
+ iv_state = ctx->tfm.state + ctx->keylen;
+ for (i = 0; i < SIZE_IN_WORDS(AES_BLOCK_SIZE); i++)
+ iv_state[i] = cpu_to_le32(cctx->iv[i]);
+
+ if (unlikely(fragmented)) {
+ /*
+ * Increment the counter manually to cope with the hardware
+ * counter overflow.
+ */
+ cctx->iv[3] = cpu_to_be32(ctr);
+ crypto_inc((u8 *)cctx->iv, AES_BLOCK_SIZE);
+ }
+ aes->resume = mtk_aes_ctr_transfer;
+
+ return mtk_aes_dma(cryp, aes, src, dst, datalen);
+}
+
+static int mtk_aes_ctr_start(struct mtk_cryp *cryp, struct mtk_aes_rec *aes)
+{
+ struct mtk_aes_ctr_ctx *cctx = mtk_aes_ctr_ctx_cast(aes->ctx);
+ struct ablkcipher_request *req = ablkcipher_request_cast(aes->areq);
+ struct mtk_aes_reqctx *rctx = ablkcipher_request_ctx(req);
+
+ mtk_aes_set_mode(aes, rctx);
+
+ memcpy(cctx->iv, req->info, AES_BLOCK_SIZE);
+ cctx->offset = 0;
+ aes->total = 0;
+
+ return mtk_aes_ctr_transfer(cryp, aes);
+}
+
/* Check and set the AES key to transform state buffer */
static int mtk_aes_setkey(struct crypto_ablkcipher *tfm,
const u8 *key, u32 keylen)
@@ -536,6 +630,16 @@ static int mtk_aes_cbc_decrypt(struct ablkcipher_request *req)
return mtk_aes_crypt(req, AES_FLAGS_CBC);
}
+static int mtk_aes_ctr_encrypt(struct ablkcipher_request *req)
+{
+ return mtk_aes_crypt(req, AES_FLAGS_ENCRYPT | AES_FLAGS_CTR);
+}
+
+static int mtk_aes_ctr_decrypt(struct ablkcipher_request *req)
+{
+ return mtk_aes_crypt(req, AES_FLAGS_CTR);
+}
+
static int mtk_aes_cra_init(struct crypto_tfm *tfm)
{
struct mtk_aes_ctx *ctx = crypto_tfm_ctx(tfm);
@@ -552,6 +656,22 @@ static int mtk_aes_cra_init(struct crypto_tfm *tfm)
return 0;
}
+static int mtk_aes_ctr_cra_init(struct crypto_tfm *tfm)
+{
+ struct mtk_aes_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct mtk_cryp *cryp = NULL;
+
+ cryp = mtk_aes_find_dev(&ctx->base);
+ if (!cryp) {
+ pr_err("can't find crypto device\n");
+ return -ENODEV;
+ }
+
+ tfm->crt_ablkcipher.reqsize = sizeof(struct mtk_aes_reqctx);
+ ctx->base.start = mtk_aes_ctr_start;
+ return 0;
+}
+
static struct crypto_alg aes_algs[] = {
{
.cra_name = "cbc(aes)",
@@ -594,6 +714,27 @@ static int mtk_aes_cra_init(struct crypto_tfm *tfm)
.decrypt = mtk_aes_ecb_decrypt,
}
},
+{
+ .cra_name = "ctr(aes)",
+ .cra_driver_name = "ctr-aes-mtk",
+ .cra_priority = 400,
+ .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER |
+ CRYPTO_ALG_ASYNC,
+ .cra_init = mtk_aes_ctr_cra_init,
+ .cra_blocksize = 1,
+ .cra_ctxsize = sizeof(struct mtk_aes_ctr_ctx),
+ .cra_alignmask = 0xf,
+ .cra_type = &crypto_ablkcipher_type,
+ .cra_module = THIS_MODULE,
+ .cra_u.ablkcipher = {
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .setkey = mtk_aes_setkey,
+ .encrypt = mtk_aes_ctr_encrypt,
+ .decrypt = mtk_aes_ctr_decrypt,
+ }
+},
};
static void mtk_aes_enc_task(unsigned long data)
--
1.9.1
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