summaryrefslogtreecommitdiff
path: root/arch/arm64/crypto/aes-glue.c
diff options
context:
space:
mode:
authorArd Biesheuvel <ard.biesheuvel@linaro.org>2018-09-10 17:41:14 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2018-09-21 08:24:50 +0300
commitdd597fb33ff0d2a158d7dd098be6dc849b7c2bcc (patch)
treeb3f3a1c2f95f4e5a087cabc435479b55a28bd4ab /arch/arm64/crypto/aes-glue.c
parent6e7de6af91b2a271ba111c6d055fc3fe1558c280 (diff)
downloadlinux-dd597fb33ff0d2a158d7dd098be6dc849b7c2bcc.tar.xz
crypto: arm64/aes-blk - add support for CTS-CBC mode
Currently, we rely on the generic CTS chaining mode wrapper to instantiate the cts(cbc(aes)) skcipher. Due to the high performance of the ARMv8 Crypto Extensions AES instructions (~1 cycles per byte), any overhead in the chaining mode layers is amplified, and so it pays off considerably to fold the CTS handling into the SIMD routines. On Cortex-A53, this results in a ~50% speedup for smaller input sizes. 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/aes-glue.c')
-rw-r--r--arch/arm64/crypto/aes-glue.c165
1 files changed, 165 insertions, 0 deletions
diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c
index 1c6934544c1f..26d2b0263ba6 100644
--- a/arch/arm64/crypto/aes-glue.c
+++ b/arch/arm64/crypto/aes-glue.c
@@ -15,6 +15,7 @@
#include <crypto/internal/hash.h>
#include <crypto/internal/simd.h>
#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
#include <linux/module.h>
#include <linux/cpufeature.h>
#include <crypto/xts.h>
@@ -31,6 +32,8 @@
#define aes_ecb_decrypt ce_aes_ecb_decrypt
#define aes_cbc_encrypt ce_aes_cbc_encrypt
#define aes_cbc_decrypt ce_aes_cbc_decrypt
+#define aes_cbc_cts_encrypt ce_aes_cbc_cts_encrypt
+#define aes_cbc_cts_decrypt ce_aes_cbc_cts_decrypt
#define aes_ctr_encrypt ce_aes_ctr_encrypt
#define aes_xts_encrypt ce_aes_xts_encrypt
#define aes_xts_decrypt ce_aes_xts_decrypt
@@ -45,6 +48,8 @@ MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 Crypto Extensions");
#define aes_ecb_decrypt neon_aes_ecb_decrypt
#define aes_cbc_encrypt neon_aes_cbc_encrypt
#define aes_cbc_decrypt neon_aes_cbc_decrypt
+#define aes_cbc_cts_encrypt neon_aes_cbc_cts_encrypt
+#define aes_cbc_cts_decrypt neon_aes_cbc_cts_decrypt
#define aes_ctr_encrypt neon_aes_ctr_encrypt
#define aes_xts_encrypt neon_aes_xts_encrypt
#define aes_xts_decrypt neon_aes_xts_decrypt
@@ -73,6 +78,11 @@ asmlinkage void aes_cbc_encrypt(u8 out[], u8 const in[], u32 const rk[],
asmlinkage void aes_cbc_decrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks, u8 iv[]);
+asmlinkage void aes_cbc_cts_encrypt(u8 out[], u8 const in[], u32 const rk[],
+ int rounds, int bytes, u8 const iv[]);
+asmlinkage void aes_cbc_cts_decrypt(u8 out[], u8 const in[], u32 const rk[],
+ int rounds, int bytes, u8 const iv[]);
+
asmlinkage void aes_ctr_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks, u8 ctr[]);
@@ -87,6 +97,12 @@ asmlinkage void aes_mac_update(u8 const in[], u32 const rk[], int rounds,
int blocks, u8 dg[], int enc_before,
int enc_after);
+struct cts_cbc_req_ctx {
+ struct scatterlist sg_src[2];
+ struct scatterlist sg_dst[2];
+ struct skcipher_request subreq;
+};
+
struct crypto_aes_xts_ctx {
struct crypto_aes_ctx key1;
struct crypto_aes_ctx __aligned(8) key2;
@@ -209,6 +225,136 @@ static int cbc_decrypt(struct skcipher_request *req)
return err;
}
+static int cts_cbc_init_tfm(struct crypto_skcipher *tfm)
+{
+ crypto_skcipher_set_reqsize(tfm, sizeof(struct cts_cbc_req_ctx));
+ return 0;
+}
+
+static int cts_cbc_encrypt(struct skcipher_request *req)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct cts_cbc_req_ctx *rctx = skcipher_request_ctx(req);
+ int err, rounds = 6 + ctx->key_length / 4;
+ int cbc_blocks = DIV_ROUND_UP(req->cryptlen, AES_BLOCK_SIZE) - 2;
+ struct scatterlist *src = req->src, *dst = req->dst;
+ struct skcipher_walk walk;
+
+ skcipher_request_set_tfm(&rctx->subreq, tfm);
+
+ if (req->cryptlen == AES_BLOCK_SIZE)
+ cbc_blocks = 1;
+
+ 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);
+ }
+ if (err)
+ return err;
+
+ if (req->cryptlen == AES_BLOCK_SIZE)
+ return 0;
+
+ dst = src = scatterwalk_ffwd(rctx->sg_src, req->src,
+ rctx->subreq.cryptlen);
+ if (req->dst != req->src)
+ dst = scatterwalk_ffwd(rctx->sg_dst, req->dst,
+ rctx->subreq.cryptlen);
+ }
+
+ /* handle ciphertext stealing */
+ skcipher_request_set_crypt(&rctx->subreq, src, dst,
+ req->cryptlen - cbc_blocks * AES_BLOCK_SIZE,
+ req->iv);
+
+ err = skcipher_walk_virt(&walk, &rctx->subreq, false);
+ if (err)
+ return err;
+
+ kernel_neon_begin();
+ aes_cbc_cts_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
+ ctx->key_enc, rounds, walk.nbytes, walk.iv);
+ kernel_neon_end();
+
+ return skcipher_walk_done(&walk, 0);
+}
+
+static int cts_cbc_decrypt(struct skcipher_request *req)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct cts_cbc_req_ctx *rctx = skcipher_request_ctx(req);
+ int err, rounds = 6 + ctx->key_length / 4;
+ int cbc_blocks = DIV_ROUND_UP(req->cryptlen, AES_BLOCK_SIZE) - 2;
+ struct scatterlist *src = req->src, *dst = req->dst;
+ struct skcipher_walk walk;
+
+ skcipher_request_set_tfm(&rctx->subreq, tfm);
+
+ if (req->cryptlen == AES_BLOCK_SIZE)
+ cbc_blocks = 1;
+
+ 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);
+ }
+ if (err)
+ return err;
+
+ if (req->cryptlen == AES_BLOCK_SIZE)
+ return 0;
+
+ dst = src = scatterwalk_ffwd(rctx->sg_src, req->src,
+ rctx->subreq.cryptlen);
+ if (req->dst != req->src)
+ dst = scatterwalk_ffwd(rctx->sg_dst, req->dst,
+ rctx->subreq.cryptlen);
+ }
+
+ /* handle ciphertext stealing */
+ skcipher_request_set_crypt(&rctx->subreq, src, dst,
+ req->cryptlen - cbc_blocks * AES_BLOCK_SIZE,
+ req->iv);
+
+ err = skcipher_walk_virt(&walk, &rctx->subreq, false);
+ if (err)
+ return err;
+
+ kernel_neon_begin();
+ aes_cbc_cts_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
+ ctx->key_dec, rounds, walk.nbytes, walk.iv);
+ kernel_neon_end();
+
+ return skcipher_walk_done(&walk, 0);
+}
+
static int ctr_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
@@ -336,6 +482,25 @@ static struct skcipher_alg aes_algs[] = { {
.decrypt = cbc_decrypt,
}, {
.base = {
+ .cra_name = "__cts(cbc(aes))",
+ .cra_driver_name = "__cts-cbc-aes-" MODE,
+ .cra_priority = PRIO,
+ .cra_flags = CRYPTO_ALG_INTERNAL,
+ .cra_blocksize = 1,
+ .cra_ctxsize = sizeof(struct crypto_aes_ctx),
+ .cra_module = THIS_MODULE,
+ },
+ .min_keysize = AES_MIN_KEY_SIZE,
+ .max_keysize = AES_MAX_KEY_SIZE,
+ .ivsize = AES_BLOCK_SIZE,
+ .chunksize = AES_BLOCK_SIZE,
+ .walksize = 2 * AES_BLOCK_SIZE,
+ .setkey = skcipher_aes_setkey,
+ .encrypt = cts_cbc_encrypt,
+ .decrypt = cts_cbc_decrypt,
+ .init = cts_cbc_init_tfm,
+}, {
+ .base = {
.cra_name = "__ctr(aes)",
.cra_driver_name = "__ctr-aes-" MODE,
.cra_priority = PRIO,