diff options
Diffstat (limited to 'arch/arm/crypto/speck-neon-glue.c')
-rw-r--r-- | arch/arm/crypto/speck-neon-glue.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/arch/arm/crypto/speck-neon-glue.c b/arch/arm/crypto/speck-neon-glue.c new file mode 100644 index 000000000000..f012c3ea998f --- /dev/null +++ b/arch/arm/crypto/speck-neon-glue.c @@ -0,0 +1,288 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * NEON-accelerated implementation of Speck128-XTS and Speck64-XTS + * + * Copyright (c) 2018 Google, Inc + * + * Note: the NIST recommendation for XTS only specifies a 128-bit block size, + * but a 64-bit version (needed for Speck64) is fairly straightforward; the math + * is just done in GF(2^64) instead of GF(2^128), with the reducing polynomial + * x^64 + x^4 + x^3 + x + 1 from the original XEX paper (Rogaway, 2004: + * "Efficient Instantiations of Tweakable Blockciphers and Refinements to Modes + * OCB and PMAC"), represented as 0x1B. + */ + +#include <asm/hwcap.h> +#include <asm/neon.h> +#include <asm/simd.h> +#include <crypto/algapi.h> +#include <crypto/gf128mul.h> +#include <crypto/internal/skcipher.h> +#include <crypto/speck.h> +#include <crypto/xts.h> +#include <linux/kernel.h> +#include <linux/module.h> + +/* The assembly functions only handle multiples of 128 bytes */ +#define SPECK_NEON_CHUNK_SIZE 128 + +/* Speck128 */ + +struct speck128_xts_tfm_ctx { + struct speck128_tfm_ctx main_key; + struct speck128_tfm_ctx tweak_key; +}; + +asmlinkage void speck128_xts_encrypt_neon(const u64 *round_keys, int nrounds, + void *dst, const void *src, + unsigned int nbytes, void *tweak); + +asmlinkage void speck128_xts_decrypt_neon(const u64 *round_keys, int nrounds, + void *dst, const void *src, + unsigned int nbytes, void *tweak); + +typedef void (*speck128_crypt_one_t)(const struct speck128_tfm_ctx *, + u8 *, const u8 *); +typedef void (*speck128_xts_crypt_many_t)(const u64 *, int, void *, + const void *, unsigned int, void *); + +static __always_inline int +__speck128_xts_crypt(struct skcipher_request *req, + speck128_crypt_one_t crypt_one, + speck128_xts_crypt_many_t crypt_many) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + const struct speck128_xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + le128 tweak; + int err; + + err = skcipher_walk_virt(&walk, req, true); + + crypto_speck128_encrypt(&ctx->tweak_key, (u8 *)&tweak, walk.iv); + + while (walk.nbytes > 0) { + unsigned int nbytes = walk.nbytes; + u8 *dst = walk.dst.virt.addr; + const u8 *src = walk.src.virt.addr; + + if (nbytes >= SPECK_NEON_CHUNK_SIZE && may_use_simd()) { + unsigned int count; + + count = round_down(nbytes, SPECK_NEON_CHUNK_SIZE); + kernel_neon_begin(); + (*crypt_many)(ctx->main_key.round_keys, + ctx->main_key.nrounds, + dst, src, count, &tweak); + kernel_neon_end(); + dst += count; + src += count; + nbytes -= count; + } + + /* Handle any remainder with generic code */ + while (nbytes >= sizeof(tweak)) { + le128_xor((le128 *)dst, (const le128 *)src, &tweak); + (*crypt_one)(&ctx->main_key, dst, dst); + le128_xor((le128 *)dst, (const le128 *)dst, &tweak); + gf128mul_x_ble(&tweak, &tweak); + + dst += sizeof(tweak); + src += sizeof(tweak); + nbytes -= sizeof(tweak); + } + err = skcipher_walk_done(&walk, nbytes); + } + + return err; +} + +static int speck128_xts_encrypt(struct skcipher_request *req) +{ + return __speck128_xts_crypt(req, crypto_speck128_encrypt, + speck128_xts_encrypt_neon); +} + +static int speck128_xts_decrypt(struct skcipher_request *req) +{ + return __speck128_xts_crypt(req, crypto_speck128_decrypt, + speck128_xts_decrypt_neon); +} + +static int speck128_xts_setkey(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keylen) +{ + struct speck128_xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm); + int err; + + err = xts_verify_key(tfm, key, keylen); + if (err) + return err; + + keylen /= 2; + + err = crypto_speck128_setkey(&ctx->main_key, key, keylen); + if (err) + return err; + + return crypto_speck128_setkey(&ctx->tweak_key, key + keylen, keylen); +} + +/* Speck64 */ + +struct speck64_xts_tfm_ctx { + struct speck64_tfm_ctx main_key; + struct speck64_tfm_ctx tweak_key; +}; + +asmlinkage void speck64_xts_encrypt_neon(const u32 *round_keys, int nrounds, + void *dst, const void *src, + unsigned int nbytes, void *tweak); + +asmlinkage void speck64_xts_decrypt_neon(const u32 *round_keys, int nrounds, + void *dst, const void *src, + unsigned int nbytes, void *tweak); + +typedef void (*speck64_crypt_one_t)(const struct speck64_tfm_ctx *, + u8 *, const u8 *); +typedef void (*speck64_xts_crypt_many_t)(const u32 *, int, void *, + const void *, unsigned int, void *); + +static __always_inline int +__speck64_xts_crypt(struct skcipher_request *req, speck64_crypt_one_t crypt_one, + speck64_xts_crypt_many_t crypt_many) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + const struct speck64_xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm); + struct skcipher_walk walk; + __le64 tweak; + int err; + + err = skcipher_walk_virt(&walk, req, true); + + crypto_speck64_encrypt(&ctx->tweak_key, (u8 *)&tweak, walk.iv); + + while (walk.nbytes > 0) { + unsigned int nbytes = walk.nbytes; + u8 *dst = walk.dst.virt.addr; + const u8 *src = walk.src.virt.addr; + + if (nbytes >= SPECK_NEON_CHUNK_SIZE && may_use_simd()) { + unsigned int count; + + count = round_down(nbytes, SPECK_NEON_CHUNK_SIZE); + kernel_neon_begin(); + (*crypt_many)(ctx->main_key.round_keys, + ctx->main_key.nrounds, + dst, src, count, &tweak); + kernel_neon_end(); + dst += count; + src += count; + nbytes -= count; + } + + /* Handle any remainder with generic code */ + while (nbytes >= sizeof(tweak)) { + *(__le64 *)dst = *(__le64 *)src ^ tweak; + (*crypt_one)(&ctx->main_key, dst, dst); + *(__le64 *)dst ^= tweak; + tweak = cpu_to_le64((le64_to_cpu(tweak) << 1) ^ + ((tweak & cpu_to_le64(1ULL << 63)) ? + 0x1B : 0)); + dst += sizeof(tweak); + src += sizeof(tweak); + nbytes -= sizeof(tweak); + } + err = skcipher_walk_done(&walk, nbytes); + } + + return err; +} + +static int speck64_xts_encrypt(struct skcipher_request *req) +{ + return __speck64_xts_crypt(req, crypto_speck64_encrypt, + speck64_xts_encrypt_neon); +} + +static int speck64_xts_decrypt(struct skcipher_request *req) +{ + return __speck64_xts_crypt(req, crypto_speck64_decrypt, + speck64_xts_decrypt_neon); +} + +static int speck64_xts_setkey(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keylen) +{ + struct speck64_xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm); + int err; + + err = xts_verify_key(tfm, key, keylen); + if (err) + return err; + + keylen /= 2; + + err = crypto_speck64_setkey(&ctx->main_key, key, keylen); + if (err) + return err; + + return crypto_speck64_setkey(&ctx->tweak_key, key + keylen, keylen); +} + +static struct skcipher_alg speck_algs[] = { + { + .base.cra_name = "xts(speck128)", + .base.cra_driver_name = "xts-speck128-neon", + .base.cra_priority = 300, + .base.cra_blocksize = SPECK128_BLOCK_SIZE, + .base.cra_ctxsize = sizeof(struct speck128_xts_tfm_ctx), + .base.cra_alignmask = 7, + .base.cra_module = THIS_MODULE, + .min_keysize = 2 * SPECK128_128_KEY_SIZE, + .max_keysize = 2 * SPECK128_256_KEY_SIZE, + .ivsize = SPECK128_BLOCK_SIZE, + .walksize = SPECK_NEON_CHUNK_SIZE, + .setkey = speck128_xts_setkey, + .encrypt = speck128_xts_encrypt, + .decrypt = speck128_xts_decrypt, + }, { + .base.cra_name = "xts(speck64)", + .base.cra_driver_name = "xts-speck64-neon", + .base.cra_priority = 300, + .base.cra_blocksize = SPECK64_BLOCK_SIZE, + .base.cra_ctxsize = sizeof(struct speck64_xts_tfm_ctx), + .base.cra_alignmask = 7, + .base.cra_module = THIS_MODULE, + .min_keysize = 2 * SPECK64_96_KEY_SIZE, + .max_keysize = 2 * SPECK64_128_KEY_SIZE, + .ivsize = SPECK64_BLOCK_SIZE, + .walksize = SPECK_NEON_CHUNK_SIZE, + .setkey = speck64_xts_setkey, + .encrypt = speck64_xts_encrypt, + .decrypt = speck64_xts_decrypt, + } +}; + +static int __init speck_neon_module_init(void) +{ + if (!(elf_hwcap & HWCAP_NEON)) + return -ENODEV; + return crypto_register_skciphers(speck_algs, ARRAY_SIZE(speck_algs)); +} + +static void __exit speck_neon_module_exit(void) +{ + crypto_unregister_skciphers(speck_algs, ARRAY_SIZE(speck_algs)); +} + +module_init(speck_neon_module_init); +module_exit(speck_neon_module_exit); + +MODULE_DESCRIPTION("Speck block cipher (NEON-accelerated)"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Eric Biggers <ebiggers@google.com>"); +MODULE_ALIAS_CRYPTO("xts(speck128)"); +MODULE_ALIAS_CRYPTO("xts-speck128-neon"); +MODULE_ALIAS_CRYPTO("xts(speck64)"); +MODULE_ALIAS_CRYPTO("xts-speck64-neon"); |