From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 8 Nov 2019 13:22:14 +0100 Subject: [PATCH] crypto: arm/chacha - remove dependency on generic ChaCha driver commit b36d8c09e710c71f6a9690b6586fea2d1c9e1e27 upstream. Instead of falling back to the generic ChaCha skcipher driver for non-SIMD cases, use a fast scalar implementation for ARM authored by Eric Biggers. This removes the module dependency on chacha-generic altogether, which also simplifies things when we expose the ChaCha library interface from this module. Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld --- arch/arm/crypto/Kconfig | 4 +- arch/arm/crypto/Makefile | 3 +- arch/arm/crypto/chacha-glue.c | 304 +++++++++++++++++++++++++++ arch/arm/crypto/chacha-neon-glue.c | 202 ------------------ arch/arm/crypto/chacha-scalar-core.S | 65 +++--- arch/arm64/crypto/chacha-neon-glue.c | 2 +- 6 files changed, 340 insertions(+), 240 deletions(-) create mode 100644 arch/arm/crypto/chacha-glue.c delete mode 100644 arch/arm/crypto/chacha-neon-glue.c --- a/arch/arm/crypto/Kconfig +++ b/arch/arm/crypto/Kconfig @@ -129,10 +129,8 @@ config CRYPTO_CRC32_ARM_CE select CRYPTO_HASH config CRYPTO_CHACHA20_NEON - tristate "NEON accelerated ChaCha stream cipher algorithms" - depends on KERNEL_MODE_NEON + tristate "NEON and scalar accelerated ChaCha stream cipher algorithms" select CRYPTO_BLKCIPHER - select CRYPTO_CHACHA20 config CRYPTO_NHPOLY1305_NEON tristate "NEON accelerated NHPoly1305 hash function (for Adiantum)" --- a/arch/arm/crypto/Makefile +++ b/arch/arm/crypto/Makefile @@ -33,7 +33,8 @@ aes-arm-ce-y := aes-ce-core.o aes-ce-glu ghash-arm-ce-y := ghash-ce-core.o ghash-ce-glue.o crct10dif-arm-ce-y := crct10dif-ce-core.o crct10dif-ce-glue.o crc32-arm-ce-y:= crc32-ce-core.o crc32-ce-glue.o -chacha-neon-y := chacha-neon-core.o chacha-neon-glue.o +chacha-neon-y := chacha-scalar-core.o chacha-glue.o +chacha-neon-$(CONFIG_KERNEL_MODE_NEON) += chacha-neon-core.o nhpoly1305-neon-y := nh-neon-core.o nhpoly1305-neon-glue.o ifdef REGENERATE_ARM_CRYPTO --- /dev/null +++ b/arch/arm/crypto/chacha-glue.c @@ -0,0 +1,304 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ARM NEON accelerated ChaCha and XChaCha stream ciphers, + * including ChaCha20 (RFC7539) + * + * Copyright (C) 2016-2019 Linaro, Ltd. + * Copyright (C) 2015 Martin Willi + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +asmlinkage void chacha_block_xor_neon(const u32 *state, u8 *dst, const u8 *src, + int nrounds); +asmlinkage void chacha_4block_xor_neon(const u32 *state, u8 *dst, const u8 *src, + int nrounds); +asmlinkage void hchacha_block_arm(const u32 *state, u32 *out, int nrounds); +asmlinkage void hchacha_block_neon(const u32 *state, u32 *out, int nrounds); + +asmlinkage void chacha_doarm(u8 *dst, const u8 *src, unsigned int bytes, + const u32 *state, int nrounds); + +static inline bool neon_usable(void) +{ + return crypto_simd_usable(); +} + +static void chacha_doneon(u32 *state, u8 *dst, const u8 *src, + unsigned int bytes, int nrounds) +{ + u8 buf[CHACHA_BLOCK_SIZE]; + + while (bytes >= CHACHA_BLOCK_SIZE * 4) { + chacha_4block_xor_neon(state, dst, src, nrounds); + bytes -= CHACHA_BLOCK_SIZE * 4; + src += CHACHA_BLOCK_SIZE * 4; + dst += CHACHA_BLOCK_SIZE * 4; + state[12] += 4; + } + while (bytes >= CHACHA_BLOCK_SIZE) { + chacha_block_xor_neon(state, dst, src, nrounds); + bytes -= CHACHA_BLOCK_SIZE; + src += CHACHA_BLOCK_SIZE; + dst += CHACHA_BLOCK_SIZE; + state[12]++; + } + if (bytes) { + memcpy(buf, src, bytes); + chacha_block_xor_neon(state, buf, buf, nrounds); + memcpy(dst, buf, bytes); + } +} + +static int chacha_stream_xor(struct skcipher_request *req, + const struct chacha_ctx *ctx, const u8 *iv, + bool neon) +{ + struct skcipher_walk walk; + u32 state[16]; + int err; + + err = skcipher_walk_virt(&walk, req, false); + + chacha_init_generic(state, ctx->key, iv); + + while (walk.nbytes > 0) { + unsigned int nbytes = walk.nbytes; + + if (nbytes < walk.total) + nbytes = round_down(nbytes, walk.stride); + + if (!neon) { + chacha_doarm(walk.dst.virt.addr, walk.src.virt.addr, + nbytes, state, ctx->nrounds); + state[12] += DIV_ROUND_UP(nbytes, CHACHA_BLOCK_SIZE); + } else { + kernel_neon_begin(); + chacha_doneon(state, walk.dst.virt.addr, + walk.src.virt.addr, nbytes, ctx->nrounds); + kernel_neon_end(); + } + err = skcipher_walk_done(&walk, walk.nbytes - nbytes); + } + + return err; +} + +static int do_chacha(struct skcipher_request *req, bool neon) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm); + + return chacha_stream_xor(req, ctx, req->iv, neon); +} + +static int chacha_arm(struct skcipher_request *req) +{ + return do_chacha(req, false); +} + +static int chacha_neon(struct skcipher_request *req) +{ + return do_chacha(req, neon_usable()); +} + +static int do_xchacha(struct skcipher_request *req, bool neon) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm); + struct chacha_ctx subctx; + u32 state[16]; + u8 real_iv[16]; + + chacha_init_generic(state, ctx->key, req->iv); + + if (!neon) { + hchacha_block_arm(state, subctx.key, ctx->nrounds); + } else { + kernel_neon_begin(); + hchacha_block_neon(state, subctx.key, ctx->nrounds); + kernel_neon_end(); + } + subctx.nrounds = ctx->nrounds; + + memcpy(&real_iv[0], req->iv + 24, 8); + memcpy(&real_iv[8], req->iv + 16, 8); + return chacha_stream_xor(req, &subctx, real_iv, neon); +} + +static int xchacha_arm(struct skcipher_request *req) +{ + return do_xchacha(req, false); +} + +static int xchacha_neon(struct skcipher_request *req) +{ + return do_xchacha(req, neon_usable()); +} + +static struct skcipher_alg arm_algs[] = { + { + .base.cra_name = "chacha20", + .base.cra_driver_name = "chacha20-arm", + .base.cra_priority = 200, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct chacha_ctx), + .base.cra_module = THIS_MODULE, + + .min_keysize = CHACHA_KEY_SIZE, + .max_keysize = CHACHA_KEY_SIZE, + .ivsize = CHACHA_IV_SIZE, + .chunksize = CHACHA_BLOCK_SIZE, + .setkey = chacha20_setkey, + .encrypt = chacha_arm, + .decrypt = chacha_arm, + }, { + .base.cra_name = "xchacha20", + .base.cra_driver_name = "xchacha20-arm", + .base.cra_priority = 200, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct chacha_ctx), + .base.cra_module = THIS_MODULE, + + .min_keysize = CHACHA_KEY_SIZE, + .max_keysize = CHACHA_KEY_SIZE, + .ivsize = XCHACHA_IV_SIZE, + .chunksize = CHACHA_BLOCK_SIZE, + .setkey = chacha20_setkey, + .encrypt = xchacha_arm, + .decrypt = xchacha_arm, + }, { + .base.cra_name = "xchacha12", + .base.cra_driver_name = "xchacha12-arm", + .base.cra_priority = 200, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct chacha_ctx), + .base.cra_module = THIS_MODULE, + + .min_keysize = CHACHA_KEY_SIZE, + .max_keysize = CHACHA_KEY_SIZE, + .ivsize = XCHACHA_IV_SIZE, + .chunksize = CHACHA_BLOCK_SIZE, + .setkey = chacha12_setkey, + .encrypt = xchacha_arm, + .decrypt = xchacha_arm, + }, +}; + +static struct skcipher_alg neon_algs[] = { + { + .base.cra_name = "chacha20", + .base.cra_driver_name = "chacha20-neon", + .base.cra_priority = 300, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct chacha_ctx), + .base.cra_module = THIS_MODULE, + + .min_keysize = CHACHA_KEY_SIZE, + .max_keysize = CHACHA_KEY_SIZE, + .ivsize = CHACHA_IV_SIZE, + .chunksize = CHACHA_BLOCK_SIZE, + .walksize = 4 * CHACHA_BLOCK_SIZE, + .setkey = chacha20_setkey, + .encrypt = chacha_neon, + .decrypt = chacha_neon, + }, { + .base.cra_name = "xchacha20", + .base.cra_driver_name = "xchacha20-neon", + .base.cra_priority = 300, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct chacha_ctx), + .base.cra_module = THIS_MODULE, + + .min_keysize = CHACHA_KEY_SIZE, + .max_keysize = CHACHA_KEY_SIZE, + .ivsize = XCHACHA_IV_SIZE, + .chunksize = CHACHA_BLOCK_SIZE, + .walksize = 4 * CHACHA_BLOCK_SIZE, + .setkey = chacha20_setkey, + .encrypt = xchacha_neon, + .decrypt = xchacha_neon, + }, { + .base.cra_name = "xchacha12", + .base.cra_driver_name = "xchacha12-neon", + .base.cra_priority = 300, + .base.cra_blocksize = 1, + .base.cra_ctxsize = sizeof(struct chacha_ctx), + .base.cra_module = THIS_MODULE, + + .min_keysize = CHACHA_KEY_SIZE, + .max_keysize = CHACHA_KEY_SIZE, + .ivsize = XCHACHA_IV_SIZE, + .chunksize = CHACHA_BLOCK_SIZE, + .walksize = 4 * CHACHA_BLOCK_SIZE, + .setkey = chacha12_setkey, + .encrypt = xchacha_neon, + .decrypt = xchacha_neon, + } +}; + +static int __init chacha_simd_mod_init(void) +{ + int err; + + err = crypto_register_skciphers(arm_algs, ARRAY_SIZE(arm_algs)); + if (err) + return err; + + if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) { + int i; + + switch (read_cpuid_part()) { + case ARM_CPU_PART_CORTEX_A7: + case ARM_CPU_PART_CORTEX_A5: + /* + * The Cortex-A7 and Cortex-A5 do not perform well with + * the NEON implementation but do incredibly with the + * scalar one and use less power. + */ + for (i = 0; i < ARRAY_SIZE(neon_algs); i++) + neon_algs[i].base.cra_priority = 0; + break; + } + + err = crypto_register_skciphers(neon_algs, ARRAY_SIZE(neon_algs)); + if (err) + crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs)); + } + return err; +} + +static void __exit chacha_simd_mod_fini(void) +{ + crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs)); + if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) + crypto_unregister_skciphers(neon_algs, ARRAY_SIZE(neon_algs)); +} + +module_init(chacha_simd_mod_init); +module_exit(chacha_simd_mod_fini); + +MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (scalar and NEON accelerated)"); +MODULE_AUTHOR("Ard Biesheuvel "); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS_CRYPTO("chacha20"); +MODULE_ALIAS_CRYPTO("chacha20-arm"); +MODULE_ALIAS_CRYPTO("xchacha20"); +MODULE_ALIAS_CRYPTO("xchacha20-arm"); +MODULE_ALIAS_CRYPTO("xchacha12"); +MODULE_ALIAS_CRYPTO("xchacha12-arm"); +#ifdef CONFIG_KERNEL_MODE_NEON +MODULE_ALIAS_CRYPTO("chacha20-neon"); +MODULE_ALIAS_CRYPTO("xchacha20-neon"); +MODULE_ALIAS_CRYPTO("xchacha12-neon"); +#endif --- a/arch/arm/crypto/chacha-neon-glue.c +++ /dev/null @@ -1,202 +0,0 @@ -/* - * ARM NEON accelerated ChaCha and XChaCha stream ciphers, - * including ChaCha20 (RFC7539) - * - * Copyright (C) 2016 Linaro, Ltd. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * Based on: - * ChaCha20 256-bit cipher algorithm, RFC7539, SIMD glue code - * - * Copyright (C) 2015 Martin Willi - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - */ - -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -asmlinkage void chacha_block_xor_neon(const u32 *state, u8 *dst, const u8 *src, - int nrounds); -asmlinkage void chacha_4block_xor_neon(const u32 *state, u8 *dst, const u8 *src, - int nrounds); -asmlinkage void hchacha_block_neon(const u32 *state, u32 *out, int nrounds); - -static void chacha_doneon(u32 *state, u8 *dst, const u8 *src, - unsigned int bytes, int nrounds) -{ - u8 buf[CHACHA_BLOCK_SIZE]; - - while (bytes >= CHACHA_BLOCK_SIZE * 4) { - chacha_4block_xor_neon(state, dst, src, nrounds); - bytes -= CHACHA_BLOCK_SIZE * 4; - src += CHACHA_BLOCK_SIZE * 4; - dst += CHACHA_BLOCK_SIZE * 4; - state[12] += 4; - } - while (bytes >= CHACHA_BLOCK_SIZE) { - chacha_block_xor_neon(state, dst, src, nrounds); - bytes -= CHACHA_BLOCK_SIZE; - src += CHACHA_BLOCK_SIZE; - dst += CHACHA_BLOCK_SIZE; - state[12]++; - } - if (bytes) { - memcpy(buf, src, bytes); - chacha_block_xor_neon(state, buf, buf, nrounds); - memcpy(dst, buf, bytes); - } -} - -static int chacha_neon_stream_xor(struct skcipher_request *req, - const struct chacha_ctx *ctx, const u8 *iv) -{ - struct skcipher_walk walk; - u32 state[16]; - int err; - - err = skcipher_walk_virt(&walk, req, false); - - crypto_chacha_init(state, ctx, iv); - - while (walk.nbytes > 0) { - unsigned int nbytes = walk.nbytes; - - if (nbytes < walk.total) - nbytes = round_down(nbytes, walk.stride); - - kernel_neon_begin(); - chacha_doneon(state, walk.dst.virt.addr, walk.src.virt.addr, - nbytes, ctx->nrounds); - kernel_neon_end(); - err = skcipher_walk_done(&walk, walk.nbytes - nbytes); - } - - return err; -} - -static int chacha_neon(struct skcipher_request *req) -{ - struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); - struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm); - - if (req->cryptlen <= CHACHA_BLOCK_SIZE || !crypto_simd_usable()) - return crypto_chacha_crypt(req); - - return chacha_neon_stream_xor(req, ctx, req->iv); -} - -static int xchacha_neon(struct skcipher_request *req) -{ - struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); - struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm); - struct chacha_ctx subctx; - u32 state[16]; - u8 real_iv[16]; - - if (req->cryptlen <= CHACHA_BLOCK_SIZE || !crypto_simd_usable()) - return crypto_xchacha_crypt(req); - - crypto_chacha_init(state, ctx, req->iv); - - kernel_neon_begin(); - hchacha_block_neon(state, subctx.key, ctx->nrounds); - kernel_neon_end(); - subctx.nrounds = ctx->nrounds; - - memcpy(&real_iv[0], req->iv + 24, 8); - memcpy(&real_iv[8], req->iv + 16, 8); - return chacha_neon_stream_xor(req, &subctx, real_iv); -} - -static struct skcipher_alg algs[] = { - { - .base.cra_name = "chacha20", - .base.cra_driver_name = "chacha20-neon", - .base.cra_priority = 300, - .base.cra_blocksize = 1, - .base.cra_ctxsize = sizeof(struct chacha_ctx), - .base.cra_module = THIS_MODULE, - - .min_keysize = CHACHA_KEY_SIZE, - .max_keysize = CHACHA_KEY_SIZE, - .ivsize = CHACHA_IV_SIZE, - .chunksize = CHACHA_BLOCK_SIZE, - .walksize = 4 * CHACHA_BLOCK_SIZE, - .setkey = crypto_chacha20_setkey, - .encrypt = chacha_neon, - .decrypt = chacha_neon, - }, { - .base.cra_name = "xchacha20", - .base.cra_driver_name = "xchacha20-neon", - .base.cra_priority = 300, - .base.cra_blocksize = 1, - .base.cra_ctxsize = sizeof(struct chacha_ctx), - .base.cra_module = THIS_MODULE, - - .min_keysize = CHACHA_KEY_SIZE, - .max_keysize = CHACHA_KEY_SIZE, - .ivsize = XCHACHA_IV_SIZE, - .chunksize = CHACHA_BLOCK_SIZE, - .walksize = 4 * CHACHA_BLOCK_SIZE, - .setkey = crypto_chacha20_setkey, - .encrypt = xchacha_neon, - .decrypt = xchacha_neon, - }, { - .base.cra_name = "xchacha12", - .base.cra_driver_name = "xchacha12-neon", - .base.cra_priority = 300, - .base.cra_blocksize = 1, - .base.cra_ctxsize = sizeof(struct chacha_ctx), - .base.cra_module = THIS_MODULE, - - .min_keysize = CHACHA_KEY_SIZE, - .max_keysize = CHACHA_KEY_SIZE, - .ivsize = XCHACHA_IV_SIZE, - .chunksize = CHACHA_BLOCK_SIZE, - .walksize = 4 * CHACHA_BLOCK_SIZE, - .setkey = crypto_chacha12_setkey, - .encrypt = xchacha_neon, - .decrypt = xchacha_neon, - } -}; - -static int __init chacha_simd_mod_init(void) -{ - if (!(elf_hwcap & HWCAP_NEON)) - return -ENODEV; - - return crypto_register_skciphers(algs, ARRAY_SIZE(algs)); -} - -static void __exit chacha_simd_mod_fini(void) -{ - crypto_unregister_skciphers(algs, ARRAY_SIZE(algs)); -} - -module_init(chacha_simd_mod_init); -module_exit(chacha_simd_mod_fini); - -MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (NEON accelerated)"); -MODULE_AUTHOR("Ard Biesheuvel "); -MODULE_LICENSE("GPL v2"); -MODULE_ALIAS_CRYPTO("chacha20"); -MODULE_ALIAS_CRYPTO("chacha20-neon"); -MODULE_ALIAS_CRYPTO("xchacha20"); -MODULE_ALIAS_CRYPTO("xchacha20-neon"); -MODULE_ALIAS_CRYPTO("xchacha12"); -MODULE_ALIAS_CRYPTO("xchacha12-neon"); --- a/arch/arm/crypto/chacha-scalar-core.S +++ b/arch/arm/crypto/chacha-scalar-core.S @@ -41,14 +41,6 @@ X14 .req r12 X15 .req r14 -.Lexpand_32byte_k: - // "expand 32-byte k" - .word 0x61707865, 0x3320646e, 0x79622d32, 0x6b206574 - -#ifdef __thumb2__ -# define adrl adr -#endif - .macro __rev out, in, t0, t1, t2 .if __LINUX_ARM_ARCH__ >= 6 rev \out, \in @@ -391,61 +383,65 @@ .endm // _chacha /* - * void chacha20_arm(u8 *out, const u8 *in, size_t len, const u32 key[8], - * const u32 iv[4]); + * void chacha_doarm(u8 *dst, const u8 *src, unsigned int bytes, + * const u32 *state, int nrounds); */ -ENTRY(chacha20_arm) +ENTRY(chacha_doarm) cmp r2, #0 // len == 0? reteq lr + ldr ip, [sp] + cmp ip, #12 + push {r0-r2,r4-r11,lr} // Push state x0-x15 onto stack. // Also store an extra copy of x10-x11 just before the state. - ldr r4, [sp, #48] // iv - mov r0, sp - sub sp, #80 - - // iv: x12-x15 - ldm r4, {X12,X13,X14,X15} - stmdb r0!, {X12,X13,X14,X15} + add X12, r3, #48 + ldm X12, {X12,X13,X14,X15} + push {X12,X13,X14,X15} + sub sp, sp, #64 - // key: x4-x11 - __ldrd X8_X10, X9_X11, r3, 24 + __ldrd X8_X10, X9_X11, r3, 40 __strd X8_X10, X9_X11, sp, 8 - stmdb r0!, {X8_X10, X9_X11} - ldm r3, {X4-X9_X11} - stmdb r0!, {X4-X9_X11} - - // constants: x0-x3 - adrl X3, .Lexpand_32byte_k - ldm X3, {X0-X3} + __strd X8_X10, X9_X11, sp, 56 + ldm r3, {X0-X9_X11} __strd X0, X1, sp, 16 __strd X2, X3, sp, 24 + __strd X4, X5, sp, 32 + __strd X6, X7, sp, 40 + __strd X8_X10, X9_X11, sp, 48 + beq 1f _chacha 20 - add sp, #76 +0: add sp, #76 pop {r4-r11, pc} -ENDPROC(chacha20_arm) + +1: _chacha 12 + b 0b +ENDPROC(chacha_doarm) /* - * void hchacha20_arm(const u32 state[16], u32 out[8]); + * void hchacha_block_arm(const u32 state[16], u32 out[8], int nrounds); */ -ENTRY(hchacha20_arm) +ENTRY(hchacha_block_arm) push {r1,r4-r11,lr} + cmp r2, #12 // ChaCha12 ? + mov r14, r0 ldmia r14!, {r0-r11} // load x0-x11 push {r10-r11} // store x10-x11 to stack ldm r14, {r10-r12,r14} // load x12-x15 sub sp, #8 + beq 1f _chacha_permute 20 // Skip over (unused0-unused1, x10-x11) - add sp, #16 +0: add sp, #16 // Fix up rotations of x12-x15 ror X12, X12, #drot @@ -458,4 +454,7 @@ ENTRY(hchacha20_arm) stm r4, {X0,X1,X2,X3,X12,X13,X14,X15} pop {r4-r11,pc} -ENDPROC(hchacha20_arm) + +1: _chacha_permute 12 + b 0b +ENDPROC(hchacha_block_arm) --- a/arch/arm64/crypto/chacha-neon-glue.c +++ b/arch/arm64/crypto/chacha-neon-glue.c @@ -1,5 +1,5 @@ /* - * ARM NEON accelerated ChaCha and XChaCha stream ciphers, + * ARM NEON and scalar accelerated ChaCha and XChaCha stream ciphers, * including ChaCha20 (RFC7539) * * Copyright (C) 2016 - 2017 Linaro, Ltd.