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Diffstat (limited to 'src/crypto/zinc/chacha20/chacha20.c')
| -rw-r--r-- | src/crypto/zinc/chacha20/chacha20.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/src/crypto/zinc/chacha20/chacha20.c b/src/crypto/zinc/chacha20/chacha20.c new file mode 100644 index 0000000..b4763c8 --- /dev/null +++ b/src/crypto/zinc/chacha20/chacha20.c @@ -0,0 +1,193 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + * + * Implementation of the ChaCha20 stream cipher. + * + * Information: https://cr.yp.to/chacha.html + */ + +#include <zinc/chacha20.h> +#include "../selftest/run.h" + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/vmalloc.h> +#include <crypto/algapi.h> // For crypto_xor_cpy. + +#if defined(CONFIG_ZINC_ARCH_X86_64) +#include "chacha20-x86_64-glue.c" +#elif defined(CONFIG_ZINC_ARCH_ARM) || defined(CONFIG_ZINC_ARCH_ARM64) +#include "chacha20-arm-glue.c" +#elif defined(CONFIG_ZINC_ARCH_MIPS) +#include "chacha20-mips-glue.c" +#else +static bool *const chacha20_nobs[] __initconst = { }; +static void __init chacha20_fpu_init(void) +{ +} +static inline bool chacha20_arch(struct chacha20_ctx *ctx, u8 *dst, + const u8 *src, size_t len, + simd_context_t *simd_context) +{ + return false; +} +static inline bool hchacha20_arch(u32 derived_key[CHACHA20_KEY_WORDS], + const u8 nonce[HCHACHA20_NONCE_SIZE], + const u8 key[HCHACHA20_KEY_SIZE], + simd_context_t *simd_context) +{ + return false; +} +#endif + +#define QUARTER_ROUND(x, a, b, c, d) ( \ + x[a] += x[b], \ + x[d] = rol32((x[d] ^ x[a]), 16), \ + x[c] += x[d], \ + x[b] = rol32((x[b] ^ x[c]), 12), \ + x[a] += x[b], \ + x[d] = rol32((x[d] ^ x[a]), 8), \ + x[c] += x[d], \ + x[b] = rol32((x[b] ^ x[c]), 7) \ +) + +#define C(i, j) (i * 4 + j) + +#define DOUBLE_ROUND(x) ( \ + /* Column Round */ \ + QUARTER_ROUND(x, C(0, 0), C(1, 0), C(2, 0), C(3, 0)), \ + QUARTER_ROUND(x, C(0, 1), C(1, 1), C(2, 1), C(3, 1)), \ + QUARTER_ROUND(x, C(0, 2), C(1, 2), C(2, 2), C(3, 2)), \ + QUARTER_ROUND(x, C(0, 3), C(1, 3), C(2, 3), C(3, 3)), \ + /* Diagonal Round */ \ + QUARTER_ROUND(x, C(0, 0), C(1, 1), C(2, 2), C(3, 3)), \ + QUARTER_ROUND(x, C(0, 1), C(1, 2), C(2, 3), C(3, 0)), \ + QUARTER_ROUND(x, C(0, 2), C(1, 3), C(2, 0), C(3, 1)), \ + QUARTER_ROUND(x, C(0, 3), C(1, 0), C(2, 1), C(3, 2)) \ +) + +#define TWENTY_ROUNDS(x) ( \ + DOUBLE_ROUND(x), \ + DOUBLE_ROUND(x), \ + DOUBLE_ROUND(x), \ + DOUBLE_ROUND(x), \ + DOUBLE_ROUND(x), \ + DOUBLE_ROUND(x), \ + DOUBLE_ROUND(x), \ + DOUBLE_ROUND(x), \ + DOUBLE_ROUND(x), \ + DOUBLE_ROUND(x) \ +) + +static void chacha20_block_generic(struct chacha20_ctx *ctx, __le32 *stream) +{ + u32 x[CHACHA20_BLOCK_WORDS]; + int i; + + for (i = 0; i < ARRAY_SIZE(x); ++i) + x[i] = ctx->state[i]; + + TWENTY_ROUNDS(x); + + for (i = 0; i < ARRAY_SIZE(x); ++i) + stream[i] = cpu_to_le32(x[i] + ctx->state[i]); + + ctx->counter[0] += 1; +} + +static void chacha20_generic(struct chacha20_ctx *ctx, u8 *out, const u8 *in, + u32 len) +{ + __le32 buf[CHACHA20_BLOCK_WORDS]; + + while (len >= CHACHA20_BLOCK_SIZE) { + chacha20_block_generic(ctx, buf); + crypto_xor_cpy(out, in, (u8 *)buf, CHACHA20_BLOCK_SIZE); + len -= CHACHA20_BLOCK_SIZE; + out += CHACHA20_BLOCK_SIZE; + in += CHACHA20_BLOCK_SIZE; + } + if (len) { + chacha20_block_generic(ctx, buf); + crypto_xor_cpy(out, in, (u8 *)buf, len); + } +} + +void chacha20(struct chacha20_ctx *ctx, u8 *dst, const u8 *src, u32 len, + simd_context_t *simd_context) +{ + if (!chacha20_arch(ctx, dst, src, len, simd_context)) + chacha20_generic(ctx, dst, src, len); +} +EXPORT_SYMBOL(chacha20); + +static void hchacha20_generic(u32 derived_key[CHACHA20_KEY_WORDS], + const u8 nonce[HCHACHA20_NONCE_SIZE], + const u8 key[HCHACHA20_KEY_SIZE]) +{ + u32 x[] = { CHACHA20_CONSTANT_EXPA, + CHACHA20_CONSTANT_ND_3, + CHACHA20_CONSTANT_2_BY, + CHACHA20_CONSTANT_TE_K, + get_unaligned_le32(key + 0), + get_unaligned_le32(key + 4), + get_unaligned_le32(key + 8), + get_unaligned_le32(key + 12), + get_unaligned_le32(key + 16), + get_unaligned_le32(key + 20), + get_unaligned_le32(key + 24), + get_unaligned_le32(key + 28), + get_unaligned_le32(nonce + 0), + get_unaligned_le32(nonce + 4), + get_unaligned_le32(nonce + 8), + get_unaligned_le32(nonce + 12) + }; + + TWENTY_ROUNDS(x); + + memcpy(derived_key + 0, x + 0, sizeof(u32) * 4); + memcpy(derived_key + 4, x + 12, sizeof(u32) * 4); +} + +/* Derived key should be 32-bit aligned */ +void hchacha20(u32 derived_key[CHACHA20_KEY_WORDS], + const u8 nonce[HCHACHA20_NONCE_SIZE], + const u8 key[HCHACHA20_KEY_SIZE], simd_context_t *simd_context) +{ + if (!hchacha20_arch(derived_key, nonce, key, simd_context)) + hchacha20_generic(derived_key, nonce, key); +} +EXPORT_SYMBOL(hchacha20); + +#include "../selftest/chacha20.c" + +static bool nosimd __initdata = false; + +#ifndef COMPAT_ZINC_IS_A_MODULE +int __init chacha20_mod_init(void) +#else +static int __init mod_init(void) +#endif +{ + if (!nosimd) + chacha20_fpu_init(); + if (!selftest_run("chacha20", chacha20_selftest, chacha20_nobs, + ARRAY_SIZE(chacha20_nobs))) + return -ENOTRECOVERABLE; + return 0; +} + +#ifdef COMPAT_ZINC_IS_A_MODULE +static void __exit mod_exit(void) +{ +} + +module_param(nosimd, bool, 0); +module_init(mod_init); +module_exit(mod_exit); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("ChaCha20 stream cipher"); +MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>"); +#endif |