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Commit 735177ca authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
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crypto: arm64/aes - implement accelerated ESSIV/CBC mode 

Add an accelerated version of the 'essiv(cbc(aes),sha256)' skcipher,
which is used by fscrypt or dm-crypt on systems where CBC mode is
signficantly more performant than XTS mode (e.g., when using a h/w
accelerator which supports the former but not the latter) This avoids
a separate call into the AES cipher for every invocation.
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 65d0042b
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arch/arm64/crypto/aes-glue.c
View file @ 735177ca
......@@ -10,6 +10,7 @@
#include <asm/simd.h>
#include <crypto/aes.h>
#include <crypto/ctr.h>
#include <crypto/sha.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/simd.h>
#include <crypto/internal/skcipher.h>
......@@ -30,6 +31,8 @@
#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_essiv_cbc_encrypt ce_aes_essiv_cbc_encrypt
#define aes_essiv_cbc_decrypt ce_aes_essiv_cbc_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
......@@ -44,6 +47,8 @@ MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 Crypto Extensions");
#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_essiv_cbc_encrypt neon_aes_essiv_cbc_encrypt
#define aes_essiv_cbc_decrypt neon_aes_essiv_cbc_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
......@@ -51,6 +56,7 @@ MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 Crypto Extensions");
MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 NEON");
MODULE_ALIAS_CRYPTO("ecb(aes)");
MODULE_ALIAS_CRYPTO("cbc(aes)");
MODULE_ALIAS_CRYPTO("essiv(cbc(aes),sha256)");
MODULE_ALIAS_CRYPTO("ctr(aes)");
MODULE_ALIAS_CRYPTO("xts(aes)");
MODULE_ALIAS_CRYPTO("cmac(aes)");
......@@ -87,6 +93,13 @@ asmlinkage void aes_xts_decrypt(u8 out[], u8 const in[], u32 const rk1[],
int rounds, int blocks, u32 const rk2[], u8 iv[],
int first);
asmlinkage void aes_essiv_cbc_encrypt(u8 out[], u8 const in[], u32 const rk1[],
int rounds, int blocks, u8 iv[],
u32 const rk2[]);
asmlinkage void aes_essiv_cbc_decrypt(u8 out[], u8 const in[], u32 const rk1[],
int rounds, int blocks, u8 iv[],
u32 const rk2[]);
asmlinkage void aes_mac_update(u8 const in[], u32 const rk[], int rounds,
int blocks, u8 dg[], int enc_before,
int enc_after);
......@@ -102,6 +115,12 @@ struct crypto_aes_xts_ctx {
struct crypto_aes_ctx __aligned(8) key2;
};
struct crypto_aes_essiv_cbc_ctx {
struct crypto_aes_ctx key1;
struct crypto_aes_ctx __aligned(8) key2;
struct crypto_shash *hash;
};
struct mac_tfm_ctx {
struct crypto_aes_ctx key;
u8 __aligned(8) consts[];
......@@ -146,6 +165,31 @@ static int xts_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
return -EINVAL;
}
static int essiv_cbc_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
unsigned int key_len)
{
struct crypto_aes_essiv_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
SHASH_DESC_ON_STACK(desc, ctx->hash);
u8 digest[SHA256_DIGEST_SIZE];
int ret;
ret = aes_expandkey(&ctx->key1, in_key, key_len);
if (ret)
goto out;
desc->tfm = ctx->hash;
crypto_shash_digest(desc, in_key, key_len, digest);
ret = aes_expandkey(&ctx->key2, digest, sizeof(digest));
if (ret)
goto out;
return 0;
out:
crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
static int ecb_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
......@@ -360,6 +404,68 @@ static int cts_cbc_decrypt(struct skcipher_request *req)
return skcipher_walk_done(&walk, 0);
}
static int essiv_cbc_init_tfm(struct crypto_skcipher *tfm)
{
struct crypto_aes_essiv_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
ctx->hash = crypto_alloc_shash("sha256", 0, 0);
if (IS_ERR(ctx->hash))
return PTR_ERR(ctx->hash);
return 0;
}
static void essiv_cbc_exit_tfm(struct crypto_skcipher *tfm)
{
struct crypto_aes_essiv_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
crypto_free_shash(ctx->hash);
}
static int essiv_cbc_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_essiv_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
int err, rounds = 6 + ctx->key1.key_length / 4;
struct skcipher_walk walk;
unsigned int blocks;
err = skcipher_walk_virt(&walk, req, false);
blocks = walk.nbytes / AES_BLOCK_SIZE;
if (blocks) {
kernel_neon_begin();
aes_essiv_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key1.key_enc, rounds, blocks,
req->iv, ctx->key2.key_enc);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
return err ?: cbc_encrypt_walk(req, &walk);
}
static int essiv_cbc_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_essiv_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
int err, rounds = 6 + ctx->key1.key_length / 4;
struct skcipher_walk walk;
unsigned int blocks;
err = skcipher_walk_virt(&walk, req, false);
blocks = walk.nbytes / AES_BLOCK_SIZE;
if (blocks) {
kernel_neon_begin();
aes_essiv_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key1.key_dec, rounds, blocks,
req->iv, ctx->key2.key_enc);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
return err ?: cbc_decrypt_walk(req, &walk);
}
static int ctr_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
......@@ -515,6 +621,24 @@ static struct skcipher_alg aes_algs[] = { {
.encrypt = cts_cbc_encrypt,
.decrypt = cts_cbc_decrypt,
.init = cts_cbc_init_tfm,
}, {
.base = {
.cra_name = "__essiv(cbc(aes),sha256)",
.cra_driver_name = "__essiv-cbc-aes-sha256-" MODE,
.cra_priority = PRIO + 1,
.cra_flags = CRYPTO_ALG_INTERNAL,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct crypto_aes_essiv_cbc_ctx),
.cra_module = THIS_MODULE,
},
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = essiv_cbc_set_key,
.encrypt = essiv_cbc_encrypt,
.decrypt = essiv_cbc_decrypt,
.init = essiv_cbc_init_tfm,
.exit = essiv_cbc_exit_tfm,
}, {
.base = {
.cra_name = "__ctr(aes)",
......
arch/arm64/crypto/aes-modes.S
View file @ 735177ca
......@@ -118,8 +118,23 @@ AES_ENDPROC(aes_ecb_decrypt)
* int blocks, u8 iv[])
* aes_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks, u8 iv[])
* aes_essiv_cbc_encrypt(u8 out[], u8 const in[], u32 const rk1[],
* int rounds, int blocks, u8 iv[],
* u32 const rk2[]);
* aes_essiv_cbc_decrypt(u8 out[], u8 const in[], u32 const rk1[],
* int rounds, int blocks, u8 iv[],
* u32 const rk2[]);
*/
AES_ENTRY(aes_essiv_cbc_encrypt)
ld1 {v4.16b}, [x5] /* get iv */
mov w8, #14 /* AES-256: 14 rounds */
enc_prepare w8, x6, x7
encrypt_block v4, w8, x6, x7, w9
enc_switch_key w3, x2, x6
b .Lcbcencloop4x
AES_ENTRY(aes_cbc_encrypt)
ld1 {v4.16b}, [x5] /* get iv */
enc_prepare w3, x2, x6
......@@ -153,13 +168,25 @@ AES_ENTRY(aes_cbc_encrypt)
st1 {v4.16b}, [x5] /* return iv */
ret
AES_ENDPROC(aes_cbc_encrypt)
AES_ENDPROC(aes_essiv_cbc_encrypt)
AES_ENTRY(aes_essiv_cbc_decrypt)
stp x29, x30, [sp, #-16]!
mov x29, sp
ld1 {cbciv.16b}, [x5] /* get iv */
mov w8, #14 /* AES-256: 14 rounds */
enc_prepare w8, x6, x7
encrypt_block cbciv, w8, x6, x7, w9
b .Lessivcbcdecstart
AES_ENTRY(aes_cbc_decrypt)
stp x29, x30, [sp, #-16]!
mov x29, sp
ld1 {cbciv.16b}, [x5] /* get iv */
.Lessivcbcdecstart:
dec_prepare w3, x2, x6
.LcbcdecloopNx:
......@@ -212,6 +239,7 @@ ST5( st1 {v4.16b}, [x0], #16 )
ldp x29, x30, [sp], #16
ret
AES_ENDPROC(aes_cbc_decrypt)
AES_ENDPROC(aes_essiv_cbc_decrypt)
/*
......
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