From: Ard Biesheuvel <ard.biesheu...@linaro.org>

Add an accelerated version of the 'essiv(cbc(aes),aes,sha256'
skcipher, which is used by fscrypt, and in some cases, by dm-crypt.
This avoids a separate call into the AES cipher for every invocation.

Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
---
 arch/arm64/crypto/aes-glue.c  | 129 ++++++++++++++++++++
 arch/arm64/crypto/aes-modes.S |  99 +++++++++++++++
 2 files changed, 228 insertions(+)

diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c
index f0ceb545bd1e..6dab2f062cea 100644
--- a/arch/arm64/crypto/aes-glue.c
+++ b/arch/arm64/crypto/aes-glue.c
@@ -12,6 +12,7 @@
 #include <asm/hwcap.h>
 #include <asm/simd.h>
 #include <crypto/aes.h>
+#include <crypto/sha.h>
 #include <crypto/internal/hash.h>
 #include <crypto/internal/simd.h>
 #include <crypto/internal/skcipher.h>
@@ -34,6 +35,8 @@
 #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
@@ -50,6 +53,8 @@ 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
@@ -93,6 +98,13 @@ 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, u32 const rk2[],
+                                     u8 iv[], int first);
+asmlinkage void aes_essiv_cbc_decrypt(u8 out[], u8 const in[], u32 const rk1[],
+                                     int rounds, int blocks, u32 const rk2[],
+                                     u8 iv[], int first);
+
 asmlinkage void aes_mac_update(u8 const in[], u32 const rk[], int rounds,
                               int blocks, u8 dg[], int enc_before,
                               int enc_after);
@@ -108,6 +120,12 @@ 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[];
@@ -145,6 +163,31 @@ 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);
@@ -361,6 +404,74 @@ 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, first, rounds = 6 + ctx->key1.key_length / 4;
+       struct skcipher_walk walk;
+       u8 iv[AES_BLOCK_SIZE];
+       unsigned int blocks;
+
+       memcpy(iv, req->iv, crypto_skcipher_ivsize(tfm));
+
+       err = skcipher_walk_virt(&walk, req, false);
+
+       for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
+               kernel_neon_begin();
+               aes_essiv_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
+                                     ctx->key1.key_enc, rounds, blocks,
+                                     ctx->key2.key_enc, iv, first);
+               kernel_neon_end();
+               err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
+       }
+
+       return err;
+}
+
+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, first, rounds = 6 + ctx->key1.key_length / 4;
+       struct skcipher_walk walk;
+       u8 iv[AES_BLOCK_SIZE];
+       unsigned int blocks;
+
+       memcpy(iv, req->iv, crypto_skcipher_ivsize(tfm));
+
+       err = skcipher_walk_virt(&walk, req, false);
+
+       for (first = 1; (blocks = (walk.nbytes / AES_BLOCK_SIZE)); first = 0) {
+               kernel_neon_begin();
+               aes_essiv_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
+                                     ctx->key1.key_dec, rounds, blocks,
+                                     ctx->key2.key_enc, iv, first);
+               kernel_neon_end();
+               err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
+       }
+
+       return err;
+}
+
 static int ctr_encrypt(struct skcipher_request *req)
 {
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
@@ -504,6 +615,24 @@ 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),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         = sizeof(u64),
+       .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)",
diff --git a/arch/arm64/crypto/aes-modes.S b/arch/arm64/crypto/aes-modes.S
index 4c7ce231963c..4ebc61375aa6 100644
--- a/arch/arm64/crypto/aes-modes.S
+++ b/arch/arm64/crypto/aes-modes.S
@@ -247,6 +247,105 @@ AES_ENDPROC(aes_cbc_cts_decrypt)
        .byte           0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
        .previous
 
+       /*
+        * aes_essiv_cbc_encrypt(u8 out[], u8 const in[], u32 const rk1[],
+        *                       int rounds, int blocks, u32 const rk2[],
+        *                       u8 iv[], int first);
+        * aes_essiv_cbc_decrypt(u8 out[], u8 const in[], u32 const rk1[],
+        *                       int rounds, int blocks, u32 const rk2[],
+        *                       u8 iv[], int first);
+        */
+
+AES_ENTRY(aes_essiv_cbc_encrypt)
+       ld1             {v4.16b}, [x6]                  /* get iv */
+       cbz             x7, .Lessivcbcencnotfirst
+
+       mov             w8, #14                         /* AES-256: 14 rounds */
+       enc_prepare     w8, x5, x7
+       mov             v4.8b, v4.8b
+       encrypt_block   v4, w8, x5, x7, w9
+
+.Lessivcbcencnotfirst:
+       enc_prepare     w3, x2, x7
+.Lessivcbcencloop4x:
+       subs            w4, w4, #4
+       bmi             .Lessivcbcenc1x
+       ld1             {v0.16b-v3.16b}, [x1], #64      /* get 4 pt blocks */
+       eor             v0.16b, v0.16b, v4.16b          /* ..and xor with iv */
+       encrypt_block   v0, w3, x2, x7, w8
+       eor             v1.16b, v1.16b, v0.16b
+       encrypt_block   v1, w3, x2, x7, w8
+       eor             v2.16b, v2.16b, v1.16b
+       encrypt_block   v2, w3, x2, x7, w8
+       eor             v3.16b, v3.16b, v2.16b
+       encrypt_block   v3, w3, x2, x7, w8
+       st1             {v0.16b-v3.16b}, [x0], #64
+       mov             v4.16b, v3.16b
+       b               .Lessivcbcencloop4x
+.Lessivcbcenc1x:
+       adds            w4, w4, #4
+       beq             .Lessivcbcencout
+.Lessivcbcencloop:
+       ld1             {v0.16b}, [x1], #16             /* get next pt block */
+       eor             v4.16b, v4.16b, v0.16b          /* ..and xor with iv */
+       encrypt_block   v4, w3, x2, x6, w7
+       st1             {v4.16b}, [x0], #16
+       subs            w4, w4, #1
+       bne             .Lessivcbcencloop
+.Lessivcbcencout:
+       st1             {v4.16b}, [x6]                  /* return iv */
+       ret
+AES_ENDPROC(aes_essiv_cbc_encrypt)
+
+
+AES_ENTRY(aes_essiv_cbc_decrypt)
+       stp             x29, x30, [sp, #-16]!
+       mov             x29, sp
+
+       ld1             {v7.16b}, [x6]                  /* get iv */
+       cbz             x7, .Lessivcbcdecnotfirst
+
+       mov             w8, #14                         /* AES-256: 14 rounds */
+       enc_prepare     w8, x5, x7
+       mov             v7.8b, v7.8b
+       encrypt_block   v7, w8, x5, x7, w9
+
+.Lessivcbcdecnotfirst:
+       dec_prepare     w3, x2, x7
+.LessivcbcdecloopNx:
+       subs            w4, w4, #4
+       bmi             .Lessivcbcdec1x
+       ld1             {v0.16b-v3.16b}, [x1], #64      /* get 4 ct blocks */
+       mov             v4.16b, v0.16b
+       mov             v5.16b, v1.16b
+       mov             v6.16b, v2.16b
+       bl              aes_decrypt_block4x
+       sub             x1, x1, #16
+       eor             v0.16b, v0.16b, v7.16b
+       eor             v1.16b, v1.16b, v4.16b
+       ld1             {v7.16b}, [x1], #16             /* reload 1 ct block */
+       eor             v2.16b, v2.16b, v5.16b
+       eor             v3.16b, v3.16b, v6.16b
+       st1             {v0.16b-v3.16b}, [x0], #64
+       b               .LessivcbcdecloopNx
+.Lessivcbcdec1x:
+       adds            w4, w4, #4
+       beq             .Lessivcbcdecout
+.Lessivcbcdecloop:
+       ld1             {v1.16b}, [x1], #16             /* get next ct block */
+       mov             v0.16b, v1.16b                  /* ...and copy to v0 */
+       decrypt_block   v0, w3, x2, x7, w8
+       eor             v0.16b, v0.16b, v7.16b          /* xor with iv => pt */
+       mov             v7.16b, v1.16b                  /* ct is next iv */
+       st1             {v0.16b}, [x0], #16
+       subs            w4, w4, #1
+       bne             .Lessivcbcdecloop
+.Lessivcbcdecout:
+       st1             {v7.16b}, [x6]                  /* return iv */
+       ldp             x29, x30, [sp], #16
+       ret
+AES_ENDPROC(aes_essiv_cbc_decrypt)
+
 
        /*
         * aes_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
-- 
2.17.1

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