diff options
Diffstat (limited to 'arch/arm/crypto/chacha-neon-glue.c')
| -rw-r--r-- | arch/arm/crypto/chacha-neon-glue.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/arch/arm/crypto/chacha-neon-glue.c b/arch/arm/crypto/chacha-neon-glue.c new file mode 100644 index 000000000000..9d6fda81986d --- /dev/null +++ b/arch/arm/crypto/chacha-neon-glue.c @@ -0,0 +1,201 @@ +/* + * ARM NEON accelerated ChaCha and XChaCha stream ciphers, + * including ChaCha20 (RFC7539) + * + * Copyright (C) 2016 Linaro, Ltd. <ard.biesheuvel@linaro.org> + * + * 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 <crypto/algapi.h> +#include <crypto/chacha.h> +#include <crypto/internal/skcipher.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include <asm/hwcap.h> +#include <asm/neon.h> +#include <asm/simd.h> + +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, + struct chacha_ctx *ctx, 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 || !may_use_simd()) + 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 || !may_use_simd()) + 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 <ard.biesheuvel@linaro.org>"); +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"); |