diff options
Diffstat (limited to 'arch/x86/crypto/poly1305_glue.c')
| -rw-r--r-- | arch/x86/crypto/poly1305_glue.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c new file mode 100644 index 000000000..f7170d764 --- /dev/null +++ b/arch/x86/crypto/poly1305_glue.c @@ -0,0 +1,207 @@ +/* + * 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(XSTATE_SSE | XSTATE_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"); |