/* * Poly1305 authenticator 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/internal/hash.h> #include <crypto/poly1305.h> #include <linux/crypto.h> #include <linux/kernel.h> #include <linux/module.h> #include <asm/fpu/api.h> #include <asm/simd.h> struct poly1305_simd_desc_ctx { struct poly1305_desc_ctx base; /* derived key u set? */ bool uset; #ifdef CONFIG_AS_AVX2 /* derived keys r^3, r^4 set? */ bool wset; #endif /* derived Poly1305 key r^2 */ u32 u[5]; /* ... silently appended r^3 and r^4 when using AVX2 */ }; asmlinkage void poly1305_block_sse2(u32 *h, const u8 *src, const u32 *r, unsigned int blocks); asmlinkage void poly1305_2block_sse2(u32 *h, const u8 *src, const u32 *r, unsigned int blocks, const u32 *u); #ifdef CONFIG_AS_AVX2 asmlinkage void poly1305_4block_avx2(u32 *h, const u8 *src, const u32 *r, unsigned int blocks, const u32 *u); static bool poly1305_use_avx2; #endif static int poly1305_simd_init(struct shash_desc *desc) { struct poly1305_simd_desc_ctx *sctx = shash_desc_ctx(desc); sctx->uset = false; #ifdef CONFIG_AS_AVX2 sctx->wset = false; #endif return crypto_poly1305_init(desc); } static void poly1305_simd_mult(u32 *a, const u32 *b) { u8 m[POLY1305_BLOCK_SIZE]; memset(m, 0, sizeof(m)); /* The poly1305 block function adds a hi-bit to the accumulator which * we don't need for key multiplication; compensate for it. */ a[4] -= 1 << 24; poly1305_block_sse2(a, m, b, 1); } static unsigned int poly1305_simd_blocks(struct poly1305_desc_ctx *dctx, const u8 *src, unsigned int srclen) { struct poly1305_simd_desc_ctx *sctx; unsigned int blocks, datalen; BUILD_BUG_ON(offsetof(struct poly1305_simd_desc_ctx, base)); sctx = container_of(dctx, struct poly1305_simd_desc_ctx, base); if (unlikely(!dctx->sset)) { datalen = crypto_poly1305_setdesckey(dctx, src, srclen); src += srclen - datalen; srclen = datalen; } #ifdef CONFIG_AS_AVX2 if (poly1305_use_avx2 && srclen >= POLY1305_BLOCK_SIZE * 4) { if (unlikely(!sctx->wset)) { if (!sctx->uset) { memcpy(sctx->u, dctx->r, sizeof(sctx->u)); poly1305_simd_mult(sctx->u, dctx->r); sctx->uset = true; } memcpy(sctx->u + 5, sctx->u, sizeof(sctx->u)); poly1305_simd_mult(sctx->u + 5, dctx->r); memcpy(sctx->u + 10, sctx->u + 5, sizeof(sctx->u)); poly1305_simd_mult(sctx->u + 10, dctx->r); sctx->wset = true; } blocks = srclen / (POLY1305_BLOCK_SIZE * 4); poly1305_4block_avx2(dctx->h, src, dctx->r, blocks, sctx->u); src += POLY1305_BLOCK_SIZE * 4 * blocks; srclen -= POLY1305_BLOCK_SIZE * 4 * blocks; } #endif if (likely(srclen >= POLY1305_BLOCK_SIZE * 2)) { if (unlikely(!sctx->uset)) { memcpy(sctx->u, dctx->r, sizeof(sctx->u)); poly1305_simd_mult(sctx->u, dctx->r); sctx->uset = true; } blocks = srclen / (POLY1305_BLOCK_SIZE * 2); poly1305_2block_sse2(dctx->h, src, dctx->r, blocks, sctx->u); src += POLY1305_BLOCK_SIZE * 2 * blocks; srclen -= POLY1305_BLOCK_SIZE * 2 * blocks; } if (srclen >= POLY1305_BLOCK_SIZE) { poly1305_block_sse2(dctx->h, src, dctx->r, 1); srclen -= POLY1305_BLOCK_SIZE; } return srclen; } static int poly1305_simd_update(struct shash_desc *desc, const u8 *src, unsigned int srclen) { struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc); unsigned int bytes; /* kernel_fpu_begin/end is costly, use fallback for small updates */ if (srclen <= 288 || !may_use_simd()) return crypto_poly1305_update(desc, src, srclen); kernel_fpu_begin(); 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) { poly1305_simd_blocks(dctx, dctx->buf, POLY1305_BLOCK_SIZE); dctx->buflen = 0; } } if (likely(srclen >= POLY1305_BLOCK_SIZE)) { bytes = poly1305_simd_blocks(dctx, src, srclen); src += srclen - bytes; srclen = bytes; } kernel_fpu_end(); if (unlikely(srclen)) { dctx->buflen = srclen; memcpy(dctx->buf, src, srclen); } return 0; } static struct shash_alg alg = { .digestsize = POLY1305_DIGEST_SIZE, .init = poly1305_simd_init, .update = poly1305_simd_update, .final = crypto_poly1305_final, .setkey = crypto_poly1305_setkey, .descsize = sizeof(struct poly1305_simd_desc_ctx), .base = { .cra_name = "poly1305", .cra_driver_name = "poly1305-simd", .cra_priority = 300, .cra_flags = CRYPTO_ALG_TYPE_SHASH, .cra_alignmask = sizeof(u32) - 1, .cra_blocksize = POLY1305_BLOCK_SIZE, .cra_module = THIS_MODULE, }, }; static int __init poly1305_simd_mod_init(void) { if (!cpu_has_xmm2) return -ENODEV; #ifdef CONFIG_AS_AVX2 poly1305_use_avx2 = cpu_has_avx && cpu_has_avx2 && cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL); alg.descsize = sizeof(struct poly1305_simd_desc_ctx); if (poly1305_use_avx2) alg.descsize += 10 * sizeof(u32); #endif return crypto_register_shash(&alg); } static void __exit poly1305_simd_mod_exit(void) { crypto_unregister_shash(&alg); } module_init(poly1305_simd_mod_init); module_exit(poly1305_simd_mod_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); MODULE_DESCRIPTION("Poly1305 authenticator"); MODULE_ALIAS_CRYPTO("poly1305"); MODULE_ALIAS_CRYPTO("poly1305-simd");