From e04a31d7f5712a757245cde7f535a105b67ca99b Mon Sep 17 00:00:00 2001 From: Ryder Lee Date: Fri, 20 Jan 2017 13:41:14 +0800 Subject: [PATCH] crypto: mediatek - add support to CTR mode This patch adds support to the CTR mode. Signed-off-by: Ryder Lee Signed-off-by: Herbert Xu --- 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 5e7c3ceea00e..bb5b4ff9ab0d 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 @@ tfm_map_err: 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 struct crypto_alg aes_algs[] = { .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) -- 2.20.1