From: Andy Polyakov Date: Fri, 9 Dec 2016 15:01:07 +0000 (+0100) Subject: poly1305/poly1305_base2_44.c: add reference base 2^44 implementation. X-Git-Tag: OpenSSL_1_1_1-pre1~2858 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=f2d78649fba17ab43244da6f09804e0d1c635e6c;p=oweals%2Fopenssl.git poly1305/poly1305_base2_44.c: add reference base 2^44 implementation. Reviewed-by: Rich Salz --- diff --git a/crypto/poly1305/poly1305_base2_44.c b/crypto/poly1305/poly1305_base2_44.c new file mode 100644 index 0000000000..20365852ff --- /dev/null +++ b/crypto/poly1305/poly1305_base2_44.c @@ -0,0 +1,171 @@ +/* + * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +/* + * This module is meant to be used as template for base 2^44 assembly + * implementation[s]. On side note compiler-generated code is not + * slower than compiler-generated base 2^64 code on [high-end] x86_64, + * even though amount of multiplications is 50% higher. Go figure... + */ +#include + +typedef unsigned char u8; +typedef unsigned int u32; +typedef unsigned long u64; +typedef unsigned __int128 u128; + +typedef struct { + u64 h[3]; + u64 s[2]; + u64 r[3]; +} poly1305_internal; + +#define POLY1305_BLOCK_SIZE 16 + +/* pick 64-bit unsigned integer in little endian order */ +static u64 U8TOU64(const unsigned char *p) +{ + return (((u64)(p[0] & 0xff)) | + ((u64)(p[1] & 0xff) << 8) | + ((u64)(p[2] & 0xff) << 16) | + ((u64)(p[3] & 0xff) << 24) | + ((u64)(p[4] & 0xff) << 32) | + ((u64)(p[5] & 0xff) << 40) | + ((u64)(p[6] & 0xff) << 48) | + ((u64)(p[7] & 0xff) << 56)); +} + +/* store a 64-bit unsigned integer in little endian */ +static void U64TO8(unsigned char *p, u64 v) +{ + p[0] = (unsigned char)((v) & 0xff); + p[1] = (unsigned char)((v >> 8) & 0xff); + p[2] = (unsigned char)((v >> 16) & 0xff); + p[3] = (unsigned char)((v >> 24) & 0xff); + p[4] = (unsigned char)((v >> 32) & 0xff); + p[5] = (unsigned char)((v >> 40) & 0xff); + p[6] = (unsigned char)((v >> 48) & 0xff); + p[7] = (unsigned char)((v >> 56) & 0xff); +} + +int poly1305_init(void *ctx, const unsigned char key[16]) +{ + poly1305_internal *st = (poly1305_internal *)ctx; + u64 r0, r1; + + /* h = 0 */ + st->h[0] = 0; + st->h[1] = 0; + st->h[2] = 0; + + r0 = U8TOU64(&key[0]) & 0x0ffffffc0fffffff; + r1 = U8TOU64(&key[8]) & 0x0ffffffc0ffffffc; + + /* break r1:r0 to three 44-bit digits, masks are 1<<44-1 */ + st->r[0] = r0 & 0x0fffffffffff; + st->r[1] = ((r0 >> 44) | (r1 << 20)) & 0x0fffffffffff; + st->r[2] = (r1 >> 24); + + st->s[0] = (st->r[1] + (st->r[1] << 2)) << 2; + st->s[1] = (st->r[2] + (st->r[2] << 2)) << 2; + + return 0; +} + +void poly1305_blocks(void *ctx, const unsigned char *inp, size_t len, + u32 padbit) +{ + poly1305_internal *st = (poly1305_internal *)ctx; + u64 r0, r1, r2; + u64 s1, s2; + u64 h0, h1, h2, c; + u128 d0, d1, d2; + u64 pad = (u64)padbit << 40; + + r0 = st->r[0]; + r1 = st->r[1]; + r2 = st->r[2]; + + s1 = st->s[0]; + s2 = st->s[1]; + + h0 = st->h[0]; + h1 = st->h[1]; + h2 = st->h[2]; + + while (len >= POLY1305_BLOCK_SIZE) { + u64 m0, m1; + + m0 = U8TOU64(inp + 0); + m1 = U8TOU64(inp + 8); + + /* h += m[i], m[i] is broken to 44-bit digits */ + h0 += m0 & 0x0fffffffffff; + h1 += ((m0 >> 44) | (m1 << 20)) & 0x0fffffffffff; + h2 += (m1 >> 24) + pad; + + /* h *= r "%" p, where "%" stands for "partial remainder" */ + d0 = ((u128)h0 * r0) + ((u128)h1 * s2) + ((u128)h2 * s1); + d1 = ((u128)h0 * r1) + ((u128)h1 * r0) + ((u128)h2 * s2); + d2 = ((u128)h0 * r2) + ((u128)h1 * r1) + ((u128)h2 * r0); + + /* "lazy" reduction step */ + h0 = (u64)d0 & 0x0fffffffffff; + h1 = (u64)(d1 += d0 >> 44) & 0x0fffffffffff; + h2 = (u64)(d2 += d1 >> 44) & 0x03ffffffffff; /* last digit is 42 bits */ + + c = (d2 >> 42); + h0 += c + (c << 2); + + inp += POLY1305_BLOCK_SIZE; + len -= POLY1305_BLOCK_SIZE; + } + + st->h[0] = h0; + st->h[1] = h1; + st->h[2] = h2; +} + +void poly1305_emit(void *ctx, unsigned char mac[16], const u32 nonce[4]) +{ + poly1305_internal *st = (poly1305_internal *) ctx; + u64 h0, h1, h2; + u64 g0, g1, g2; + u128 t; + u64 mask; + + h0 = st->h[0]; + h1 = st->h[1]; + h2 = st->h[2]; + + /* after "lazy" reduction, convert 44+bit digits to 64-bit ones */ + h0 = (u64)(t = (u128)h0 + (h1 << 44)); h1 >>= 20; + h1 = (u64)(t = (u128)h1 + (h2 << 24) + (t >> 64)); h2 >>= 40; + h2 += (u64)(t >> 64); + + /* compare to modulus by computing h + -p */ + g0 = (u64)(t = (u128)h0 + 5); + g1 = (u64)(t = (u128)h1 + (t >> 64)); + g2 = h2 + (u64)(t >> 64); + + /* if there was carry into 131st bit, h1:h0 = g1:g0 */ + mask = 0 - (g2 >> 2); + g0 &= mask; + g1 &= mask; + mask = ~mask; + h0 = (h0 & mask) | g0; + h1 = (h1 & mask) | g1; + + /* mac = (h + nonce) % (2^128) */ + h0 = (u64)(t = (u128)h0 + nonce[0] + ((u64)nonce[1]<<32)); + h1 = (u64)(t = (u128)h1 + nonce[2] + ((u64)nonce[3]<<32) + (t >> 64)); + + U64TO8(mac + 0, h0); + U64TO8(mac + 8, h1); +}