From d52db5188a87dcdf8e5bf024f45543b362a1a85f Mon Sep 17 00:00:00 2001 From: Cyrille Pitchen Date: Mon, 3 Oct 2016 14:33:16 +0200 Subject: [PATCH] crypto: atmel-aes - add support to the XTS mode This patch adds the xts(aes) algorithm, which is supported from hardware version 0x500 and above (sama5d2x). Signed-off-by: Cyrille Pitchen Signed-off-by: Herbert Xu --- drivers/crypto/atmel-aes-regs.h | 4 + drivers/crypto/atmel-aes.c | 185 ++++++++++++++++++++++++++++++-- 2 files changed, 183 insertions(+), 6 deletions(-) diff --git a/drivers/crypto/atmel-aes-regs.h b/drivers/crypto/atmel-aes-regs.h index 6c2951bb70b1..0ec04407b533 100644 --- a/drivers/crypto/atmel-aes-regs.h +++ b/drivers/crypto/atmel-aes-regs.h @@ -28,6 +28,7 @@ #define AES_MR_OPMOD_CFB (0x3 << 12) #define AES_MR_OPMOD_CTR (0x4 << 12) #define AES_MR_OPMOD_GCM (0x5 << 12) +#define AES_MR_OPMOD_XTS (0x6 << 12) #define AES_MR_LOD (0x1 << 15) #define AES_MR_CFBS_MASK (0x7 << 16) #define AES_MR_CFBS_128b (0x0 << 16) @@ -67,6 +68,9 @@ #define AES_CTRR 0x98 #define AES_GCMHR(x) (0x9c + ((x) * 0x04)) +#define AES_TWR(x) (0xc0 + ((x) * 0x04)) +#define AES_ALPHAR(x) (0xd0 + ((x) * 0x04)) + #define AES_HW_VERSION 0xFC #endif /* __ATMEL_AES_REGS_H__ */ diff --git a/drivers/crypto/atmel-aes.c b/drivers/crypto/atmel-aes.c index 1d9e7bd3f377..6b656f4a9378 100644 --- a/drivers/crypto/atmel-aes.c +++ b/drivers/crypto/atmel-aes.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include #include @@ -68,6 +69,7 @@ #define AES_FLAGS_CFB8 (AES_MR_OPMOD_CFB | AES_MR_CFBS_8b) #define AES_FLAGS_CTR AES_MR_OPMOD_CTR #define AES_FLAGS_GCM AES_MR_OPMOD_GCM +#define AES_FLAGS_XTS AES_MR_OPMOD_XTS #define AES_FLAGS_MODE_MASK (AES_FLAGS_OPMODE_MASK | \ AES_FLAGS_ENCRYPT | \ @@ -89,6 +91,7 @@ struct atmel_aes_caps { bool has_cfb64; bool has_ctr32; bool has_gcm; + bool has_xts; u32 max_burst_size; }; @@ -135,6 +138,12 @@ struct atmel_aes_gcm_ctx { atmel_aes_fn_t ghash_resume; }; +struct atmel_aes_xts_ctx { + struct atmel_aes_base_ctx base; + + u32 key2[AES_KEYSIZE_256 / sizeof(u32)]; +}; + struct atmel_aes_reqctx { unsigned long mode; }; @@ -282,6 +291,20 @@ static const char *atmel_aes_reg_name(u32 offset, char *tmp, size_t sz) snprintf(tmp, sz, "GCMHR[%u]", (offset - AES_GCMHR(0)) >> 2); break; + case AES_TWR(0): + case AES_TWR(1): + case AES_TWR(2): + case AES_TWR(3): + snprintf(tmp, sz, "TWR[%u]", (offset - AES_TWR(0)) >> 2); + break; + + case AES_ALPHAR(0): + case AES_ALPHAR(1): + case AES_ALPHAR(2): + case AES_ALPHAR(3): + snprintf(tmp, sz, "ALPHAR[%u]", (offset - AES_ALPHAR(0)) >> 2); + break; + default: snprintf(tmp, sz, "0x%02x", offset); break; @@ -453,15 +476,15 @@ static inline int atmel_aes_complete(struct atmel_aes_dev *dd, int err) return err; } -static void atmel_aes_write_ctrl(struct atmel_aes_dev *dd, bool use_dma, - const u32 *iv) +static void atmel_aes_write_ctrl_key(struct atmel_aes_dev *dd, bool use_dma, + const u32 *iv, const u32 *key, int keylen) { u32 valmr = 0; /* MR register must be set before IV registers */ - if (dd->ctx->keylen == AES_KEYSIZE_128) + if (keylen == AES_KEYSIZE_128) valmr |= AES_MR_KEYSIZE_128; - else if (dd->ctx->keylen == AES_KEYSIZE_192) + else if (keylen == AES_KEYSIZE_192) valmr |= AES_MR_KEYSIZE_192; else valmr |= AES_MR_KEYSIZE_256; @@ -478,13 +501,19 @@ static void atmel_aes_write_ctrl(struct atmel_aes_dev *dd, bool use_dma, atmel_aes_write(dd, AES_MR, valmr); - atmel_aes_write_n(dd, AES_KEYWR(0), dd->ctx->key, - SIZE_IN_WORDS(dd->ctx->keylen)); + atmel_aes_write_n(dd, AES_KEYWR(0), key, SIZE_IN_WORDS(keylen)); if (iv && (valmr & AES_MR_OPMOD_MASK) != AES_MR_OPMOD_ECB) atmel_aes_write_block(dd, AES_IVR(0), iv); } +static inline void atmel_aes_write_ctrl(struct atmel_aes_dev *dd, bool use_dma, + const u32 *iv) + +{ + atmel_aes_write_ctrl_key(dd, use_dma, iv, + dd->ctx->key, dd->ctx->keylen); +} /* CPU transfer */ @@ -1769,6 +1798,137 @@ static struct aead_alg aes_gcm_alg = { }; +/* xts functions */ + +static inline struct atmel_aes_xts_ctx * +atmel_aes_xts_ctx_cast(struct atmel_aes_base_ctx *ctx) +{ + return container_of(ctx, struct atmel_aes_xts_ctx, base); +} + +static int atmel_aes_xts_process_data(struct atmel_aes_dev *dd); + +static int atmel_aes_xts_start(struct atmel_aes_dev *dd) +{ + struct atmel_aes_xts_ctx *ctx = atmel_aes_xts_ctx_cast(dd->ctx); + struct ablkcipher_request *req = ablkcipher_request_cast(dd->areq); + struct atmel_aes_reqctx *rctx = ablkcipher_request_ctx(req); + unsigned long flags; + int err; + + atmel_aes_set_mode(dd, rctx); + + err = atmel_aes_hw_init(dd); + if (err) + return atmel_aes_complete(dd, err); + + /* Compute the tweak value from req->info with ecb(aes). */ + flags = dd->flags; + dd->flags &= ~AES_FLAGS_MODE_MASK; + dd->flags |= (AES_FLAGS_ECB | AES_FLAGS_ENCRYPT); + atmel_aes_write_ctrl_key(dd, false, NULL, + ctx->key2, ctx->base.keylen); + dd->flags = flags; + + atmel_aes_write_block(dd, AES_IDATAR(0), req->info); + return atmel_aes_wait_for_data_ready(dd, atmel_aes_xts_process_data); +} + +static int atmel_aes_xts_process_data(struct atmel_aes_dev *dd) +{ + struct ablkcipher_request *req = ablkcipher_request_cast(dd->areq); + bool use_dma = (req->nbytes >= ATMEL_AES_DMA_THRESHOLD); + u32 tweak[AES_BLOCK_SIZE / sizeof(u32)]; + static const u32 one[AES_BLOCK_SIZE / sizeof(u32)] = {cpu_to_le32(1), }; + u8 *tweak_bytes = (u8 *)tweak; + int i; + + /* Read the computed ciphered tweak value. */ + atmel_aes_read_block(dd, AES_ODATAR(0), tweak); + /* + * Hardware quirk: + * the order of the ciphered tweak bytes need to be reversed before + * writing them into the ODATARx registers. + */ + for (i = 0; i < AES_BLOCK_SIZE/2; ++i) { + u8 tmp = tweak_bytes[AES_BLOCK_SIZE - 1 - i]; + + tweak_bytes[AES_BLOCK_SIZE - 1 - i] = tweak_bytes[i]; + tweak_bytes[i] = tmp; + } + + /* Process the data. */ + atmel_aes_write_ctrl(dd, use_dma, NULL); + atmel_aes_write_block(dd, AES_TWR(0), tweak); + atmel_aes_write_block(dd, AES_ALPHAR(0), one); + if (use_dma) + return atmel_aes_dma_start(dd, req->src, req->dst, req->nbytes, + atmel_aes_transfer_complete); + + return atmel_aes_cpu_start(dd, req->src, req->dst, req->nbytes, + atmel_aes_transfer_complete); +} + +static int atmel_aes_xts_setkey(struct crypto_ablkcipher *tfm, const u8 *key, + unsigned int keylen) +{ + struct atmel_aes_xts_ctx *ctx = crypto_ablkcipher_ctx(tfm); + int err; + + err = xts_check_key(crypto_ablkcipher_tfm(tfm), key, keylen); + if (err) + return err; + + memcpy(ctx->base.key, key, keylen/2); + memcpy(ctx->key2, key + keylen/2, keylen/2); + ctx->base.keylen = keylen/2; + + return 0; +} + +static int atmel_aes_xts_encrypt(struct ablkcipher_request *req) +{ + return atmel_aes_crypt(req, AES_FLAGS_XTS | AES_FLAGS_ENCRYPT); +} + +static int atmel_aes_xts_decrypt(struct ablkcipher_request *req) +{ + return atmel_aes_crypt(req, AES_FLAGS_XTS); +} + +static int atmel_aes_xts_cra_init(struct crypto_tfm *tfm) +{ + struct atmel_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm); + + tfm->crt_ablkcipher.reqsize = sizeof(struct atmel_aes_reqctx); + ctx->base.start = atmel_aes_xts_start; + + return 0; +} + +static struct crypto_alg aes_xts_alg = { + .cra_name = "xts(aes)", + .cra_driver_name = "atmel-xts-aes", + .cra_priority = ATMEL_AES_PRIORITY, + .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct atmel_aes_xts_ctx), + .cra_alignmask = 0xf, + .cra_type = &crypto_ablkcipher_type, + .cra_module = THIS_MODULE, + .cra_init = atmel_aes_xts_cra_init, + .cra_exit = atmel_aes_cra_exit, + .cra_u.ablkcipher = { + .min_keysize = 2 * AES_MIN_KEY_SIZE, + .max_keysize = 2 * AES_MAX_KEY_SIZE, + .ivsize = AES_BLOCK_SIZE, + .setkey = atmel_aes_xts_setkey, + .encrypt = atmel_aes_xts_encrypt, + .decrypt = atmel_aes_xts_decrypt, + } +}; + + /* Probe functions */ static int atmel_aes_buff_init(struct atmel_aes_dev *dd) @@ -1877,6 +2037,9 @@ static void atmel_aes_unregister_algs(struct atmel_aes_dev *dd) { int i; + if (dd->caps.has_xts) + crypto_unregister_alg(&aes_xts_alg); + if (dd->caps.has_gcm) crypto_unregister_aead(&aes_gcm_alg); @@ -1909,8 +2072,16 @@ static int atmel_aes_register_algs(struct atmel_aes_dev *dd) goto err_aes_gcm_alg; } + if (dd->caps.has_xts) { + err = crypto_register_alg(&aes_xts_alg); + if (err) + goto err_aes_xts_alg; + } + return 0; +err_aes_xts_alg: + crypto_unregister_aead(&aes_gcm_alg); err_aes_gcm_alg: crypto_unregister_alg(&aes_cfb64_alg); err_aes_cfb64_alg: @@ -1928,6 +2099,7 @@ static void atmel_aes_get_cap(struct atmel_aes_dev *dd) dd->caps.has_cfb64 = 0; dd->caps.has_ctr32 = 0; dd->caps.has_gcm = 0; + dd->caps.has_xts = 0; dd->caps.max_burst_size = 1; /* keep only major version number */ @@ -1937,6 +2109,7 @@ static void atmel_aes_get_cap(struct atmel_aes_dev *dd) dd->caps.has_cfb64 = 1; dd->caps.has_ctr32 = 1; dd->caps.has_gcm = 1; + dd->caps.has_xts = 1; dd->caps.max_burst_size = 4; break; case 0x200: -- 2.39.5