From 98e87e3d933b8e504ea41b8857c038d2cd06cddc Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Thu, 19 Apr 2018 18:41:54 +0200 Subject: [PATCH 5/8] crypto: crypto4xx - add aes-ctr support This patch adds support for the aes-ctr skcipher. name : ctr(aes) driver : ctr-aes-ppc4xx module : crypto4xx priority : 300 refcnt : 1 selftest : passed internal : no type : skcipher async : yes blocksize : 16 min keysize : 16 max keysize : 32 ivsize : 16 chunksize : 16 walksize : 16 The hardware uses only the last 32-bits as the counter while the kernel tests (aes_ctr_enc_tv_template[4] for example) expect that the whole IV is a counter. To make this work, the driver will fallback if the counter is going to overlow. The aead's crypto4xx_setup_fallback() function is renamed to crypto4xx_aead_setup_fallback. Signed-off-by: Christian Lamparter Signed-off-by: Herbert Xu --- drivers/crypto/amcc/crypto4xx_alg.c | 91 ++++++++++++++++++++++++++-- drivers/crypto/amcc/crypto4xx_core.c | 37 +++++++++++ drivers/crypto/amcc/crypto4xx_core.h | 5 ++ 3 files changed, 127 insertions(+), 6 deletions(-) --- a/drivers/crypto/amcc/crypto4xx_alg.c +++ b/drivers/crypto/amcc/crypto4xx_alg.c @@ -241,6 +241,85 @@ int crypto4xx_rfc3686_decrypt(struct skc ctx->sa_out, ctx->sa_len, 0); } +static int +crypto4xx_ctr_crypt(struct skcipher_request *req, bool encrypt) +{ + struct crypto_skcipher *cipher = crypto_skcipher_reqtfm(req); + struct crypto4xx_ctx *ctx = crypto_skcipher_ctx(cipher); + size_t iv_len = crypto_skcipher_ivsize(cipher); + unsigned int counter = be32_to_cpup((__be32 *)(req->iv + iv_len - 4)); + unsigned int nblks = ALIGN(req->cryptlen, AES_BLOCK_SIZE) / + AES_BLOCK_SIZE; + + /* + * The hardware uses only the last 32-bits as the counter while the + * kernel tests (aes_ctr_enc_tv_template[4] for example) expect that + * the whole IV is a counter. So fallback if the counter is going to + * overlow. + */ + if (counter + nblks < counter) { + struct skcipher_request *subreq = skcipher_request_ctx(req); + int ret; + + skcipher_request_set_tfm(subreq, ctx->sw_cipher.cipher); + skcipher_request_set_callback(subreq, req->base.flags, + NULL, NULL); + skcipher_request_set_crypt(subreq, req->src, req->dst, + req->cryptlen, req->iv); + ret = encrypt ? crypto_skcipher_encrypt(subreq) + : crypto_skcipher_decrypt(subreq); + skcipher_request_zero(subreq); + return ret; + } + + return encrypt ? crypto4xx_encrypt_iv(req) + : crypto4xx_decrypt_iv(req); +} + +static int crypto4xx_sk_setup_fallback(struct crypto4xx_ctx *ctx, + struct crypto_skcipher *cipher, + const u8 *key, + unsigned int keylen) +{ + int rc; + + crypto_skcipher_clear_flags(ctx->sw_cipher.cipher, + CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(ctx->sw_cipher.cipher, + crypto_skcipher_get_flags(cipher) & CRYPTO_TFM_REQ_MASK); + rc = crypto_skcipher_setkey(ctx->sw_cipher.cipher, key, keylen); + crypto_skcipher_clear_flags(cipher, CRYPTO_TFM_RES_MASK); + crypto_skcipher_set_flags(cipher, + crypto_skcipher_get_flags(ctx->sw_cipher.cipher) & + CRYPTO_TFM_RES_MASK); + + return rc; +} + +int crypto4xx_setkey_aes_ctr(struct crypto_skcipher *cipher, + const u8 *key, unsigned int keylen) +{ + struct crypto4xx_ctx *ctx = crypto_skcipher_ctx(cipher); + int rc; + + rc = crypto4xx_sk_setup_fallback(ctx, cipher, key, keylen); + if (rc) + return rc; + + return crypto4xx_setkey_aes(cipher, key, keylen, + CRYPTO_MODE_CTR, CRYPTO_FEEDBACK_MODE_NO_FB); +} + +int crypto4xx_encrypt_ctr(struct skcipher_request *req) +{ + return crypto4xx_ctr_crypt(req, true); +} + +int crypto4xx_decrypt_ctr(struct skcipher_request *req) +{ + return crypto4xx_ctr_crypt(req, false); +} + static inline bool crypto4xx_aead_need_fallback(struct aead_request *req, bool is_ccm, bool decrypt) { @@ -283,10 +362,10 @@ static int crypto4xx_aead_fallback(struc crypto_aead_encrypt(subreq); } -static int crypto4xx_setup_fallback(struct crypto4xx_ctx *ctx, - struct crypto_aead *cipher, - const u8 *key, - unsigned int keylen) +static int crypto4xx_aead_setup_fallback(struct crypto4xx_ctx *ctx, + struct crypto_aead *cipher, + const u8 *key, + unsigned int keylen) { int rc; @@ -314,7 +393,7 @@ int crypto4xx_setkey_aes_ccm(struct cryp struct dynamic_sa_ctl *sa; int rc = 0; - rc = crypto4xx_setup_fallback(ctx, cipher, key, keylen); + rc = crypto4xx_aead_setup_fallback(ctx, cipher, key, keylen); if (rc) return rc; @@ -473,7 +552,7 @@ int crypto4xx_setkey_aes_gcm(struct cryp return -EINVAL; } - rc = crypto4xx_setup_fallback(ctx, cipher, key, keylen); + rc = crypto4xx_aead_setup_fallback(ctx, cipher, key, keylen); if (rc) return rc; --- a/drivers/crypto/amcc/crypto4xx_core.c +++ b/drivers/crypto/amcc/crypto4xx_core.c @@ -946,6 +946,19 @@ static int crypto4xx_sk_init(struct cryp struct crypto4xx_alg *amcc_alg; struct crypto4xx_ctx *ctx = crypto_skcipher_ctx(sk); + if (alg->base.cra_flags & CRYPTO_ALG_NEED_FALLBACK) { + ctx->sw_cipher.cipher = + crypto_alloc_skcipher(alg->base.cra_name, 0, + CRYPTO_ALG_NEED_FALLBACK | + CRYPTO_ALG_ASYNC); + if (IS_ERR(ctx->sw_cipher.cipher)) + return PTR_ERR(ctx->sw_cipher.cipher); + + crypto_skcipher_set_reqsize(sk, + sizeof(struct skcipher_request) + 32 + + crypto_skcipher_reqsize(ctx->sw_cipher.cipher)); + } + amcc_alg = container_of(alg, struct crypto4xx_alg, alg.u.cipher); crypto4xx_ctx_init(amcc_alg, ctx); return 0; @@ -961,6 +974,8 @@ static void crypto4xx_sk_exit(struct cry struct crypto4xx_ctx *ctx = crypto_skcipher_ctx(sk); crypto4xx_common_exit(ctx); + if (ctx->sw_cipher.cipher) + crypto_free_skcipher(ctx->sw_cipher.cipher); } static int crypto4xx_aead_init(struct crypto_aead *tfm) @@ -1150,6 +1165,28 @@ static struct crypto4xx_alg_common crypt .init = crypto4xx_sk_init, .exit = crypto4xx_sk_exit, } }, + { .type = CRYPTO_ALG_TYPE_SKCIPHER, .u.cipher = { + .base = { + .cra_name = "ctr(aes)", + .cra_driver_name = "ctr-aes-ppc4xx", + .cra_priority = CRYPTO4XX_CRYPTO_PRIORITY, + .cra_flags = CRYPTO_ALG_TYPE_SKCIPHER | + CRYPTO_ALG_NEED_FALLBACK | + CRYPTO_ALG_ASYNC | + CRYPTO_ALG_KERN_DRIVER_ONLY, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct crypto4xx_ctx), + .cra_module = THIS_MODULE, + }, + .min_keysize = AES_MIN_KEY_SIZE, + .max_keysize = AES_MAX_KEY_SIZE, + .ivsize = AES_IV_SIZE, + .setkey = crypto4xx_setkey_aes_ctr, + .encrypt = crypto4xx_encrypt_ctr, + .decrypt = crypto4xx_decrypt_ctr, + .init = crypto4xx_sk_init, + .exit = crypto4xx_sk_exit, + } }, { .type = CRYPTO_ALG_TYPE_SKCIPHER, .u.cipher = { .base = { .cra_name = "rfc3686(ctr(aes))", --- a/drivers/crypto/amcc/crypto4xx_core.h +++ b/drivers/crypto/amcc/crypto4xx_core.h @@ -128,6 +128,7 @@ struct crypto4xx_ctx { __le32 iv_nonce; u32 sa_len; union { + struct crypto_skcipher *cipher; struct crypto_aead *aead; } sw_cipher; }; @@ -163,12 +164,16 @@ int crypto4xx_setkey_aes_cbc(struct cryp const u8 *key, unsigned int keylen); int crypto4xx_setkey_aes_cfb(struct crypto_skcipher *cipher, const u8 *key, unsigned int keylen); +int crypto4xx_setkey_aes_ctr(struct crypto_skcipher *cipher, + const u8 *key, unsigned int keylen); int crypto4xx_setkey_aes_ecb(struct crypto_skcipher *cipher, const u8 *key, unsigned int keylen); int crypto4xx_setkey_aes_ofb(struct crypto_skcipher *cipher, const u8 *key, unsigned int keylen); int crypto4xx_setkey_rfc3686(struct crypto_skcipher *cipher, const u8 *key, unsigned int keylen); +int crypto4xx_encrypt_ctr(struct skcipher_request *req); +int crypto4xx_decrypt_ctr(struct skcipher_request *req); int crypto4xx_encrypt_iv(struct skcipher_request *req); int crypto4xx_decrypt_iv(struct skcipher_request *req); int crypto4xx_encrypt_noiv(struct skcipher_request *req);