diff options
Diffstat (limited to 'arch/x86/crypto/poly1305_glue.c')
-rw-r--r-- | arch/x86/crypto/poly1305_glue.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c new file mode 100644 index 0000000000..1dfb8af48a --- /dev/null +++ b/arch/x86/crypto/poly1305_glue.c @@ -0,0 +1,290 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ + +#include <crypto/algapi.h> +#include <crypto/internal/hash.h> +#include <crypto/internal/poly1305.h> +#include <crypto/internal/simd.h> +#include <linux/crypto.h> +#include <linux/jump_label.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/sizes.h> +#include <asm/intel-family.h> +#include <asm/simd.h> + +asmlinkage void poly1305_init_x86_64(void *ctx, + const u8 key[POLY1305_BLOCK_SIZE]); +asmlinkage void poly1305_blocks_x86_64(void *ctx, const u8 *inp, + const size_t len, const u32 padbit); +asmlinkage void poly1305_emit_x86_64(void *ctx, u8 mac[POLY1305_DIGEST_SIZE], + const u32 nonce[4]); +asmlinkage void poly1305_emit_avx(void *ctx, u8 mac[POLY1305_DIGEST_SIZE], + const u32 nonce[4]); +asmlinkage void poly1305_blocks_avx(void *ctx, const u8 *inp, const size_t len, + const u32 padbit); +asmlinkage void poly1305_blocks_avx2(void *ctx, const u8 *inp, const size_t len, + const u32 padbit); +asmlinkage void poly1305_blocks_avx512(void *ctx, const u8 *inp, + const size_t len, const u32 padbit); + +static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx); +static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx2); +static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx512); + +struct poly1305_arch_internal { + union { + struct { + u32 h[5]; + u32 is_base2_26; + }; + u64 hs[3]; + }; + u64 r[2]; + u64 pad; + struct { u32 r2, r1, r4, r3; } rn[9]; +}; + +/* The AVX code uses base 2^26, while the scalar code uses base 2^64. If we hit + * the unfortunate situation of using AVX and then having to go back to scalar + * -- because the user is silly and has called the update function from two + * separate contexts -- then we need to convert back to the original base before + * proceeding. It is possible to reason that the initial reduction below is + * sufficient given the implementation invariants. However, for an avoidance of + * doubt and because this is not performance critical, we do the full reduction + * anyway. Z3 proof of below function: https://xn--4db.cc/ltPtHCKN/py + */ +static void convert_to_base2_64(void *ctx) +{ + struct poly1305_arch_internal *state = ctx; + u32 cy; + + if (!state->is_base2_26) + return; + + cy = state->h[0] >> 26; state->h[0] &= 0x3ffffff; state->h[1] += cy; + cy = state->h[1] >> 26; state->h[1] &= 0x3ffffff; state->h[2] += cy; + cy = state->h[2] >> 26; state->h[2] &= 0x3ffffff; state->h[3] += cy; + cy = state->h[3] >> 26; state->h[3] &= 0x3ffffff; state->h[4] += cy; + state->hs[0] = ((u64)state->h[2] << 52) | ((u64)state->h[1] << 26) | state->h[0]; + state->hs[1] = ((u64)state->h[4] << 40) | ((u64)state->h[3] << 14) | (state->h[2] >> 12); + state->hs[2] = state->h[4] >> 24; +#define ULT(a, b) ((a ^ ((a ^ b) | ((a - b) ^ b))) >> (sizeof(a) * 8 - 1)) + cy = (state->hs[2] >> 2) + (state->hs[2] & ~3ULL); + state->hs[2] &= 3; + state->hs[0] += cy; + state->hs[1] += (cy = ULT(state->hs[0], cy)); + state->hs[2] += ULT(state->hs[1], cy); +#undef ULT + state->is_base2_26 = 0; +} + +static void poly1305_simd_init(void *ctx, const u8 key[POLY1305_BLOCK_SIZE]) +{ + poly1305_init_x86_64(ctx, key); +} + +static void poly1305_simd_blocks(void *ctx, const u8 *inp, size_t len, + const u32 padbit) +{ + struct poly1305_arch_internal *state = ctx; + + /* SIMD disables preemption, so relax after processing each page. */ + BUILD_BUG_ON(SZ_4K < POLY1305_BLOCK_SIZE || + SZ_4K % POLY1305_BLOCK_SIZE); + + if (!static_branch_likely(&poly1305_use_avx) || + (len < (POLY1305_BLOCK_SIZE * 18) && !state->is_base2_26) || + !crypto_simd_usable()) { + convert_to_base2_64(ctx); + poly1305_blocks_x86_64(ctx, inp, len, padbit); + return; + } + + do { + const size_t bytes = min_t(size_t, len, SZ_4K); + + kernel_fpu_begin(); + if (IS_ENABLED(CONFIG_AS_AVX512) && static_branch_likely(&poly1305_use_avx512)) + poly1305_blocks_avx512(ctx, inp, bytes, padbit); + else if (static_branch_likely(&poly1305_use_avx2)) + poly1305_blocks_avx2(ctx, inp, bytes, padbit); + else + poly1305_blocks_avx(ctx, inp, bytes, padbit); + kernel_fpu_end(); + + len -= bytes; + inp += bytes; + } while (len); +} + +static void poly1305_simd_emit(void *ctx, u8 mac[POLY1305_DIGEST_SIZE], + const u32 nonce[4]) +{ + if (!static_branch_likely(&poly1305_use_avx)) + poly1305_emit_x86_64(ctx, mac, nonce); + else + poly1305_emit_avx(ctx, mac, nonce); +} + +void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE]) +{ + poly1305_simd_init(&dctx->h, key); + dctx->s[0] = get_unaligned_le32(&key[16]); + dctx->s[1] = get_unaligned_le32(&key[20]); + dctx->s[2] = get_unaligned_le32(&key[24]); + dctx->s[3] = get_unaligned_le32(&key[28]); + dctx->buflen = 0; + dctx->sset = true; +} +EXPORT_SYMBOL(poly1305_init_arch); + +static unsigned int crypto_poly1305_setdctxkey(struct poly1305_desc_ctx *dctx, + const u8 *inp, unsigned int len) +{ + unsigned int acc = 0; + if (unlikely(!dctx->sset)) { + if (!dctx->rset && len >= POLY1305_BLOCK_SIZE) { + poly1305_simd_init(&dctx->h, inp); + inp += POLY1305_BLOCK_SIZE; + len -= POLY1305_BLOCK_SIZE; + acc += POLY1305_BLOCK_SIZE; + dctx->rset = 1; + } + if (len >= POLY1305_BLOCK_SIZE) { + dctx->s[0] = get_unaligned_le32(&inp[0]); + dctx->s[1] = get_unaligned_le32(&inp[4]); + dctx->s[2] = get_unaligned_le32(&inp[8]); + dctx->s[3] = get_unaligned_le32(&inp[12]); + acc += POLY1305_BLOCK_SIZE; + dctx->sset = true; + } + } + return acc; +} + +void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src, + unsigned int srclen) +{ + unsigned int bytes, used; + + if (unlikely(dctx->buflen)) { + bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen); + memcpy(dctx->buf + dctx->buflen, src, bytes); + src += bytes; + srclen -= bytes; + dctx->buflen += bytes; + + if (dctx->buflen == POLY1305_BLOCK_SIZE) { + if (likely(!crypto_poly1305_setdctxkey(dctx, dctx->buf, POLY1305_BLOCK_SIZE))) + poly1305_simd_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 1); + dctx->buflen = 0; + } + } + + if (likely(srclen >= POLY1305_BLOCK_SIZE)) { + bytes = round_down(srclen, POLY1305_BLOCK_SIZE); + srclen -= bytes; + used = crypto_poly1305_setdctxkey(dctx, src, bytes); + if (likely(bytes - used)) + poly1305_simd_blocks(&dctx->h, src + used, bytes - used, 1); + src += bytes; + } + + if (unlikely(srclen)) { + dctx->buflen = srclen; + memcpy(dctx->buf, src, srclen); + } +} +EXPORT_SYMBOL(poly1305_update_arch); + +void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst) +{ + if (unlikely(dctx->buflen)) { + dctx->buf[dctx->buflen++] = 1; + memset(dctx->buf + dctx->buflen, 0, + POLY1305_BLOCK_SIZE - dctx->buflen); + poly1305_simd_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0); + } + + poly1305_simd_emit(&dctx->h, dst, dctx->s); + memzero_explicit(dctx, sizeof(*dctx)); +} +EXPORT_SYMBOL(poly1305_final_arch); + +static int crypto_poly1305_init(struct shash_desc *desc) +{ + struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc); + + *dctx = (struct poly1305_desc_ctx){}; + return 0; +} + +static int crypto_poly1305_update(struct shash_desc *desc, + const u8 *src, unsigned int srclen) +{ + struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc); + + poly1305_update_arch(dctx, src, srclen); + return 0; +} + +static int crypto_poly1305_final(struct shash_desc *desc, u8 *dst) +{ + struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc); + + if (unlikely(!dctx->sset)) + return -ENOKEY; + + poly1305_final_arch(dctx, dst); + return 0; +} + +static struct shash_alg alg = { + .digestsize = POLY1305_DIGEST_SIZE, + .init = crypto_poly1305_init, + .update = crypto_poly1305_update, + .final = crypto_poly1305_final, + .descsize = sizeof(struct poly1305_desc_ctx), + .base = { + .cra_name = "poly1305", + .cra_driver_name = "poly1305-simd", + .cra_priority = 300, + .cra_blocksize = POLY1305_BLOCK_SIZE, + .cra_module = THIS_MODULE, + }, +}; + +static int __init poly1305_simd_mod_init(void) +{ + if (boot_cpu_has(X86_FEATURE_AVX) && + cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) + static_branch_enable(&poly1305_use_avx); + if (boot_cpu_has(X86_FEATURE_AVX) && boot_cpu_has(X86_FEATURE_AVX2) && + cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) + static_branch_enable(&poly1305_use_avx2); + if (IS_ENABLED(CONFIG_AS_AVX512) && boot_cpu_has(X86_FEATURE_AVX) && + boot_cpu_has(X86_FEATURE_AVX2) && boot_cpu_has(X86_FEATURE_AVX512F) && + cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM | XFEATURE_MASK_AVX512, NULL) && + /* Skylake downclocks unacceptably much when using zmm, but later generations are fast. */ + boot_cpu_data.x86_model != INTEL_FAM6_SKYLAKE_X) + static_branch_enable(&poly1305_use_avx512); + return IS_REACHABLE(CONFIG_CRYPTO_HASH) ? crypto_register_shash(&alg) : 0; +} + +static void __exit poly1305_simd_mod_exit(void) +{ + if (IS_REACHABLE(CONFIG_CRYPTO_HASH)) + crypto_unregister_shash(&alg); +} + +module_init(poly1305_simd_mod_init); +module_exit(poly1305_simd_mod_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>"); +MODULE_DESCRIPTION("Poly1305 authenticator"); +MODULE_ALIAS_CRYPTO("poly1305"); +MODULE_ALIAS_CRYPTO("poly1305-simd"); |