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author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2019-08-19 17:17:35 +0300 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2019-08-30 18:05:27 +1000 |
commit | 65d0042b529048b80dcb1b6b4a738a8f71828146 (patch) | |
tree | 9a901ca468349aa80155eef9982e1e5827dd7f58 /arch/arm64/crypto | |
parent | f975abb23c6f3e551b5b9ac991941756bb1c2f3d (diff) | |
download | lwn-65d0042b529048b80dcb1b6b4a738a8f71828146.tar.gz lwn-65d0042b529048b80dcb1b6b4a738a8f71828146.zip |
crypto: arm64/aes-cts-cbc - factor out CBC en/decryption of a walk
The plain CBC driver and the CTS one share some code that iterates over
a scatterwalk and invokes the CBC asm code to do the processing. The
upcoming ESSIV/CBC mode will clone that pattern for the third time, so
let's factor it out first.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/arm64/crypto')
-rw-r--r-- | arch/arm64/crypto/aes-glue.c | 82 |
1 files changed, 40 insertions, 42 deletions
diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c index 55d6d4838708..23abf335f1ee 100644 --- a/arch/arm64/crypto/aes-glue.c +++ b/arch/arm64/crypto/aes-glue.c @@ -186,46 +186,64 @@ static int ecb_decrypt(struct skcipher_request *req) return err; } -static int cbc_encrypt(struct skcipher_request *req) +static int cbc_encrypt_walk(struct skcipher_request *req, + struct skcipher_walk *walk) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); - int err, rounds = 6 + ctx->key_length / 4; - struct skcipher_walk walk; + int err = 0, rounds = 6 + ctx->key_length / 4; unsigned int blocks; - err = skcipher_walk_virt(&walk, req, false); - - while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { + while ((blocks = (walk->nbytes / AES_BLOCK_SIZE))) { kernel_neon_begin(); - aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr, - ctx->key_enc, rounds, blocks, walk.iv); + aes_cbc_encrypt(walk->dst.virt.addr, walk->src.virt.addr, + ctx->key_enc, rounds, blocks, walk->iv); kernel_neon_end(); - err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + err = skcipher_walk_done(walk, walk->nbytes % AES_BLOCK_SIZE); } return err; } -static int cbc_decrypt(struct skcipher_request *req) +static int cbc_encrypt(struct skcipher_request *req) { - struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); - struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); - int err, rounds = 6 + ctx->key_length / 4; struct skcipher_walk walk; - unsigned int blocks; + int err; err = skcipher_walk_virt(&walk, req, false); + if (err) + return err; + return cbc_encrypt_walk(req, &walk); +} - while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { +static int cbc_decrypt_walk(struct skcipher_request *req, + struct skcipher_walk *walk) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); + int err = 0, rounds = 6 + ctx->key_length / 4; + unsigned int blocks; + + while ((blocks = (walk->nbytes / AES_BLOCK_SIZE))) { kernel_neon_begin(); - aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr, - ctx->key_dec, rounds, blocks, walk.iv); + aes_cbc_decrypt(walk->dst.virt.addr, walk->src.virt.addr, + ctx->key_dec, rounds, blocks, walk->iv); kernel_neon_end(); - err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + err = skcipher_walk_done(walk, walk->nbytes % AES_BLOCK_SIZE); } return err; } +static int cbc_decrypt(struct skcipher_request *req) +{ + struct skcipher_walk walk; + int err; + + err = skcipher_walk_virt(&walk, req, false); + if (err) + return err; + return cbc_decrypt_walk(req, &walk); +} + static int cts_cbc_init_tfm(struct crypto_skcipher *tfm) { crypto_skcipher_set_reqsize(tfm, sizeof(struct cts_cbc_req_ctx)); @@ -251,22 +269,12 @@ static int cts_cbc_encrypt(struct skcipher_request *req) } if (cbc_blocks > 0) { - unsigned int blocks; - skcipher_request_set_crypt(&rctx->subreq, req->src, req->dst, cbc_blocks * AES_BLOCK_SIZE, req->iv); - err = skcipher_walk_virt(&walk, &rctx->subreq, false); - - while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { - kernel_neon_begin(); - aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr, - ctx->key_enc, rounds, blocks, walk.iv); - kernel_neon_end(); - err = skcipher_walk_done(&walk, - walk.nbytes % AES_BLOCK_SIZE); - } + err = skcipher_walk_virt(&walk, &rctx->subreq, false) ?: + cbc_encrypt_walk(&rctx->subreq, &walk); if (err) return err; @@ -316,22 +324,12 @@ static int cts_cbc_decrypt(struct skcipher_request *req) } if (cbc_blocks > 0) { - unsigned int blocks; - skcipher_request_set_crypt(&rctx->subreq, req->src, req->dst, cbc_blocks * AES_BLOCK_SIZE, req->iv); - err = skcipher_walk_virt(&walk, &rctx->subreq, false); - - while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { - kernel_neon_begin(); - aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr, - ctx->key_dec, rounds, blocks, walk.iv); - kernel_neon_end(); - err = skcipher_walk_done(&walk, - walk.nbytes % AES_BLOCK_SIZE); - } + err = skcipher_walk_virt(&walk, &rctx->subreq, false) ?: + cbc_decrypt_walk(&rctx->subreq, &walk); if (err) return err; |