b5acbf9148
Apart from public and internal header files, there is a third type called local header files, which are located next to source files in the source directory. Currently, they have different suffixes like '*_lcl.h', '*_local.h', or '*_int.h' This commit changes the different suffixes to '*_local.h' uniformly. Reviewed-by: Richard Levitte <levitte@openssl.org> (Merged from https://github.com/openssl/openssl/pull/9681)
531 lines
16 KiB
C
531 lines
16 KiB
C
/*
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* Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the OpenSSL license (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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#include <stdlib.h>
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#include <string.h>
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#include <openssl/crypto.h>
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#include "crypto/poly1305.h"
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#include "poly1305_local.h"
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size_t Poly1305_ctx_size(void)
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{
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return sizeof(struct poly1305_context);
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}
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/* pick 32-bit unsigned integer in little endian order */
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static unsigned int U8TOU32(const unsigned char *p)
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{
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return (((unsigned int)(p[0] & 0xff)) |
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((unsigned int)(p[1] & 0xff) << 8) |
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((unsigned int)(p[2] & 0xff) << 16) |
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((unsigned int)(p[3] & 0xff) << 24));
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}
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/*
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* Implementations can be classified by amount of significant bits in
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* words making up the multi-precision value, or in other words radix
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* or base of numerical representation, e.g. base 2^64, base 2^32,
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* base 2^26. Complementary characteristic is how wide is the result of
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* multiplication of pair of digits, e.g. it would take 128 bits to
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* accommodate multiplication result in base 2^64 case. These are used
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* interchangeably. To describe implementation that is. But interface
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* is designed to isolate this so that low-level primitives implemented
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* in assembly can be self-contained/self-coherent.
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*/
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#ifndef POLY1305_ASM
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/*
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* Even though there is __int128 reference implementation targeting
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* 64-bit platforms provided below, it's not obvious that it's optimal
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* choice for every one of them. Depending on instruction set overall
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* amount of instructions can be comparable to one in __int64
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* implementation. Amount of multiplication instructions would be lower,
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* but not necessarily overall. And in out-of-order execution context,
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* it is the latter that can be crucial...
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*
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* On related note. Poly1305 author, D. J. Bernstein, discusses and
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* provides floating-point implementations of the algorithm in question.
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* It made a lot of sense by the time of introduction, because most
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* then-modern processors didn't have pipelined integer multiplier.
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* [Not to mention that some had non-constant timing for integer
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* multiplications.] Floating-point instructions on the other hand could
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* be issued every cycle, which allowed to achieve better performance.
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* Nowadays, with SIMD and/or out-or-order execution, shared or
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* even emulated FPU, it's more complicated, and floating-point
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* implementation is not necessarily optimal choice in every situation,
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* rather contrary...
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*
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* <appro@openssl.org>
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*/
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typedef unsigned int u32;
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/*
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* poly1305_blocks processes a multiple of POLY1305_BLOCK_SIZE blocks
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* of |inp| no longer than |len|. Behaviour for |len| not divisible by
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* block size is unspecified in general case, even though in reference
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* implementation the trailing chunk is simply ignored. Per algorithm
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* specification, every input block, complete or last partial, is to be
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* padded with a bit past most significant byte. The latter kind is then
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* padded with zeros till block size. This last partial block padding
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* is caller(*)'s responsibility, and because of this the last partial
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* block is always processed with separate call with |len| set to
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* POLY1305_BLOCK_SIZE and |padbit| to 0. In all other cases |padbit|
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* should be set to 1 to perform implicit padding with 128th bit.
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* poly1305_blocks does not actually check for this constraint though,
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* it's caller(*)'s responsibility to comply.
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*
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* (*) In the context "caller" is not application code, but higher
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* level Poly1305_* from this very module, so that quirks are
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* handled locally.
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*/
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static void
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poly1305_blocks(void *ctx, const unsigned char *inp, size_t len, u32 padbit);
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/*
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* Type-agnostic "rip-off" from constant_time.h
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*/
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# define CONSTANT_TIME_CARRY(a,b) ( \
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(a ^ ((a ^ b) | ((a - b) ^ b))) >> (sizeof(a) * 8 - 1) \
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)
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# if (defined(__SIZEOF_INT128__) && __SIZEOF_INT128__==16) && \
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(defined(__SIZEOF_LONG__) && __SIZEOF_LONG__==8)
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typedef unsigned long u64;
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typedef __uint128_t u128;
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typedef struct {
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u64 h[3];
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u64 r[2];
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} poly1305_internal;
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/* pick 32-bit unsigned integer in little endian order */
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static u64 U8TOU64(const unsigned char *p)
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{
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return (((u64)(p[0] & 0xff)) |
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((u64)(p[1] & 0xff) << 8) |
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((u64)(p[2] & 0xff) << 16) |
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((u64)(p[3] & 0xff) << 24) |
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((u64)(p[4] & 0xff) << 32) |
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((u64)(p[5] & 0xff) << 40) |
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((u64)(p[6] & 0xff) << 48) |
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((u64)(p[7] & 0xff) << 56));
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}
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/* store a 32-bit unsigned integer in little endian */
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static void U64TO8(unsigned char *p, u64 v)
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{
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p[0] = (unsigned char)((v) & 0xff);
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p[1] = (unsigned char)((v >> 8) & 0xff);
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p[2] = (unsigned char)((v >> 16) & 0xff);
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p[3] = (unsigned char)((v >> 24) & 0xff);
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p[4] = (unsigned char)((v >> 32) & 0xff);
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p[5] = (unsigned char)((v >> 40) & 0xff);
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p[6] = (unsigned char)((v >> 48) & 0xff);
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p[7] = (unsigned char)((v >> 56) & 0xff);
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}
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static void poly1305_init(void *ctx, const unsigned char key[16])
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{
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poly1305_internal *st = (poly1305_internal *) ctx;
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/* h = 0 */
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st->h[0] = 0;
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st->h[1] = 0;
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st->h[2] = 0;
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/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
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st->r[0] = U8TOU64(&key[0]) & 0x0ffffffc0fffffff;
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st->r[1] = U8TOU64(&key[8]) & 0x0ffffffc0ffffffc;
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}
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static void
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poly1305_blocks(void *ctx, const unsigned char *inp, size_t len, u32 padbit)
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{
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poly1305_internal *st = (poly1305_internal *)ctx;
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u64 r0, r1;
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u64 s1;
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u64 h0, h1, h2, c;
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u128 d0, d1;
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r0 = st->r[0];
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r1 = st->r[1];
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s1 = r1 + (r1 >> 2);
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h0 = st->h[0];
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h1 = st->h[1];
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h2 = st->h[2];
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while (len >= POLY1305_BLOCK_SIZE) {
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/* h += m[i] */
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h0 = (u64)(d0 = (u128)h0 + U8TOU64(inp + 0));
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h1 = (u64)(d1 = (u128)h1 + (d0 >> 64) + U8TOU64(inp + 8));
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/*
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* padbit can be zero only when original len was
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* POLY1306_BLOCK_SIZE, but we don't check
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*/
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h2 += (u64)(d1 >> 64) + padbit;
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/* h *= r "%" p, where "%" stands for "partial remainder" */
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d0 = ((u128)h0 * r0) +
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((u128)h1 * s1);
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d1 = ((u128)h0 * r1) +
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((u128)h1 * r0) +
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(h2 * s1);
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h2 = (h2 * r0);
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/* last reduction step: */
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/* a) h2:h0 = h2<<128 + d1<<64 + d0 */
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h0 = (u64)d0;
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h1 = (u64)(d1 += d0 >> 64);
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h2 += (u64)(d1 >> 64);
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/* b) (h2:h0 += (h2:h0>>130) * 5) %= 2^130 */
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c = (h2 >> 2) + (h2 & ~3UL);
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h2 &= 3;
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h0 += c;
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h1 += (c = CONSTANT_TIME_CARRY(h0,c));
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h2 += CONSTANT_TIME_CARRY(h1,c);
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/*
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* Occasional overflows to 3rd bit of h2 are taken care of
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* "naturally". If after this point we end up at the top of
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* this loop, then the overflow bit will be accounted for
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* in next iteration. If we end up in poly1305_emit, then
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* comparison to modulus below will still count as "carry
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* into 131st bit", so that properly reduced value will be
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* picked in conditional move.
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*/
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inp += POLY1305_BLOCK_SIZE;
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len -= POLY1305_BLOCK_SIZE;
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}
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st->h[0] = h0;
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st->h[1] = h1;
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st->h[2] = h2;
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}
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static void poly1305_emit(void *ctx, unsigned char mac[16],
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const u32 nonce[4])
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{
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poly1305_internal *st = (poly1305_internal *) ctx;
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u64 h0, h1, h2;
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u64 g0, g1, g2;
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u128 t;
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u64 mask;
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h0 = st->h[0];
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h1 = st->h[1];
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h2 = st->h[2];
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/* compare to modulus by computing h + -p */
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g0 = (u64)(t = (u128)h0 + 5);
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g1 = (u64)(t = (u128)h1 + (t >> 64));
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g2 = h2 + (u64)(t >> 64);
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/* if there was carry into 131st bit, h1:h0 = g1:g0 */
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mask = 0 - (g2 >> 2);
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g0 &= mask;
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g1 &= mask;
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mask = ~mask;
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h0 = (h0 & mask) | g0;
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h1 = (h1 & mask) | g1;
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/* mac = (h + nonce) % (2^128) */
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h0 = (u64)(t = (u128)h0 + nonce[0] + ((u64)nonce[1]<<32));
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h1 = (u64)(t = (u128)h1 + nonce[2] + ((u64)nonce[3]<<32) + (t >> 64));
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U64TO8(mac + 0, h0);
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U64TO8(mac + 8, h1);
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}
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# else
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# if defined(_WIN32) && !defined(__MINGW32__)
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typedef unsigned __int64 u64;
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# elif defined(__arch64__)
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typedef unsigned long u64;
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# else
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typedef unsigned long long u64;
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# endif
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typedef struct {
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u32 h[5];
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u32 r[4];
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} poly1305_internal;
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/* store a 32-bit unsigned integer in little endian */
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static void U32TO8(unsigned char *p, unsigned int v)
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{
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p[0] = (unsigned char)((v) & 0xff);
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p[1] = (unsigned char)((v >> 8) & 0xff);
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p[2] = (unsigned char)((v >> 16) & 0xff);
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p[3] = (unsigned char)((v >> 24) & 0xff);
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}
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static void poly1305_init(void *ctx, const unsigned char key[16])
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{
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poly1305_internal *st = (poly1305_internal *) ctx;
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/* h = 0 */
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st->h[0] = 0;
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st->h[1] = 0;
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st->h[2] = 0;
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st->h[3] = 0;
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st->h[4] = 0;
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/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
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st->r[0] = U8TOU32(&key[0]) & 0x0fffffff;
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st->r[1] = U8TOU32(&key[4]) & 0x0ffffffc;
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st->r[2] = U8TOU32(&key[8]) & 0x0ffffffc;
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st->r[3] = U8TOU32(&key[12]) & 0x0ffffffc;
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}
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static void
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poly1305_blocks(void *ctx, const unsigned char *inp, size_t len, u32 padbit)
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{
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poly1305_internal *st = (poly1305_internal *)ctx;
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u32 r0, r1, r2, r3;
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u32 s1, s2, s3;
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u32 h0, h1, h2, h3, h4, c;
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u64 d0, d1, d2, d3;
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r0 = st->r[0];
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r1 = st->r[1];
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r2 = st->r[2];
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r3 = st->r[3];
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s1 = r1 + (r1 >> 2);
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s2 = r2 + (r2 >> 2);
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s3 = r3 + (r3 >> 2);
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h0 = st->h[0];
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h1 = st->h[1];
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h2 = st->h[2];
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h3 = st->h[3];
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h4 = st->h[4];
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while (len >= POLY1305_BLOCK_SIZE) {
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/* h += m[i] */
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h0 = (u32)(d0 = (u64)h0 + U8TOU32(inp + 0));
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h1 = (u32)(d1 = (u64)h1 + (d0 >> 32) + U8TOU32(inp + 4));
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h2 = (u32)(d2 = (u64)h2 + (d1 >> 32) + U8TOU32(inp + 8));
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h3 = (u32)(d3 = (u64)h3 + (d2 >> 32) + U8TOU32(inp + 12));
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h4 += (u32)(d3 >> 32) + padbit;
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/* h *= r "%" p, where "%" stands for "partial remainder" */
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d0 = ((u64)h0 * r0) +
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((u64)h1 * s3) +
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((u64)h2 * s2) +
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((u64)h3 * s1);
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d1 = ((u64)h0 * r1) +
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((u64)h1 * r0) +
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((u64)h2 * s3) +
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((u64)h3 * s2) +
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(h4 * s1);
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d2 = ((u64)h0 * r2) +
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((u64)h1 * r1) +
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((u64)h2 * r0) +
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((u64)h3 * s3) +
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(h4 * s2);
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d3 = ((u64)h0 * r3) +
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((u64)h1 * r2) +
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((u64)h2 * r1) +
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((u64)h3 * r0) +
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(h4 * s3);
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h4 = (h4 * r0);
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/* last reduction step: */
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/* a) h4:h0 = h4<<128 + d3<<96 + d2<<64 + d1<<32 + d0 */
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h0 = (u32)d0;
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h1 = (u32)(d1 += d0 >> 32);
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h2 = (u32)(d2 += d1 >> 32);
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h3 = (u32)(d3 += d2 >> 32);
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h4 += (u32)(d3 >> 32);
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/* b) (h4:h0 += (h4:h0>>130) * 5) %= 2^130 */
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c = (h4 >> 2) + (h4 & ~3U);
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h4 &= 3;
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h0 += c;
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h1 += (c = CONSTANT_TIME_CARRY(h0,c));
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h2 += (c = CONSTANT_TIME_CARRY(h1,c));
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h3 += (c = CONSTANT_TIME_CARRY(h2,c));
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h4 += CONSTANT_TIME_CARRY(h3,c);
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/*
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* Occasional overflows to 3rd bit of h4 are taken care of
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* "naturally". If after this point we end up at the top of
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* this loop, then the overflow bit will be accounted for
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* in next iteration. If we end up in poly1305_emit, then
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* comparison to modulus below will still count as "carry
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* into 131st bit", so that properly reduced value will be
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* picked in conditional move.
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*/
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inp += POLY1305_BLOCK_SIZE;
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len -= POLY1305_BLOCK_SIZE;
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}
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st->h[0] = h0;
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st->h[1] = h1;
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st->h[2] = h2;
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st->h[3] = h3;
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st->h[4] = h4;
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}
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static void poly1305_emit(void *ctx, unsigned char mac[16],
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const u32 nonce[4])
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{
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poly1305_internal *st = (poly1305_internal *) ctx;
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u32 h0, h1, h2, h3, h4;
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u32 g0, g1, g2, g3, g4;
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u64 t;
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u32 mask;
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h0 = st->h[0];
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h1 = st->h[1];
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h2 = st->h[2];
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h3 = st->h[3];
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h4 = st->h[4];
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/* compare to modulus by computing h + -p */
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g0 = (u32)(t = (u64)h0 + 5);
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g1 = (u32)(t = (u64)h1 + (t >> 32));
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g2 = (u32)(t = (u64)h2 + (t >> 32));
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g3 = (u32)(t = (u64)h3 + (t >> 32));
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g4 = h4 + (u32)(t >> 32);
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/* if there was carry into 131st bit, h3:h0 = g3:g0 */
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mask = 0 - (g4 >> 2);
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g0 &= mask;
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g1 &= mask;
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g2 &= mask;
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g3 &= mask;
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mask = ~mask;
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h0 = (h0 & mask) | g0;
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h1 = (h1 & mask) | g1;
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h2 = (h2 & mask) | g2;
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h3 = (h3 & mask) | g3;
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/* mac = (h + nonce) % (2^128) */
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h0 = (u32)(t = (u64)h0 + nonce[0]);
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h1 = (u32)(t = (u64)h1 + (t >> 32) + nonce[1]);
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h2 = (u32)(t = (u64)h2 + (t >> 32) + nonce[2]);
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h3 = (u32)(t = (u64)h3 + (t >> 32) + nonce[3]);
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U32TO8(mac + 0, h0);
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U32TO8(mac + 4, h1);
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U32TO8(mac + 8, h2);
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U32TO8(mac + 12, h3);
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}
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# endif
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#else
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int poly1305_init(void *ctx, const unsigned char key[16], void *func);
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void poly1305_blocks(void *ctx, const unsigned char *inp, size_t len,
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unsigned int padbit);
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void poly1305_emit(void *ctx, unsigned char mac[16],
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const unsigned int nonce[4]);
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#endif
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void Poly1305_Init(POLY1305 *ctx, const unsigned char key[32])
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{
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ctx->nonce[0] = U8TOU32(&key[16]);
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ctx->nonce[1] = U8TOU32(&key[20]);
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ctx->nonce[2] = U8TOU32(&key[24]);
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ctx->nonce[3] = U8TOU32(&key[28]);
|
|
|
|
#ifndef POLY1305_ASM
|
|
poly1305_init(ctx->opaque, key);
|
|
#else
|
|
/*
|
|
* Unlike reference poly1305_init assembly counterpart is expected
|
|
* to return a value: non-zero if it initializes ctx->func, and zero
|
|
* otherwise. Latter is to simplify assembly in cases when there no
|
|
* multiple code paths to switch between.
|
|
*/
|
|
if (!poly1305_init(ctx->opaque, key, &ctx->func)) {
|
|
ctx->func.blocks = poly1305_blocks;
|
|
ctx->func.emit = poly1305_emit;
|
|
}
|
|
#endif
|
|
|
|
ctx->num = 0;
|
|
|
|
}
|
|
|
|
#ifdef POLY1305_ASM
|
|
/*
|
|
* This "eclipses" poly1305_blocks and poly1305_emit, but it's
|
|
* conscious choice imposed by -Wshadow compiler warnings.
|
|
*/
|
|
# define poly1305_blocks (*poly1305_blocks_p)
|
|
# define poly1305_emit (*poly1305_emit_p)
|
|
#endif
|
|
|
|
void Poly1305_Update(POLY1305 *ctx, const unsigned char *inp, size_t len)
|
|
{
|
|
#ifdef POLY1305_ASM
|
|
/*
|
|
* As documented, poly1305_blocks is never called with input
|
|
* longer than single block and padbit argument set to 0. This
|
|
* property is fluently used in assembly modules to optimize
|
|
* padbit handling on loop boundary.
|
|
*/
|
|
poly1305_blocks_f poly1305_blocks_p = ctx->func.blocks;
|
|
#endif
|
|
size_t rem, num;
|
|
|
|
if ((num = ctx->num)) {
|
|
rem = POLY1305_BLOCK_SIZE - num;
|
|
if (len >= rem) {
|
|
memcpy(ctx->data + num, inp, rem);
|
|
poly1305_blocks(ctx->opaque, ctx->data, POLY1305_BLOCK_SIZE, 1);
|
|
inp += rem;
|
|
len -= rem;
|
|
} else {
|
|
/* Still not enough data to process a block. */
|
|
memcpy(ctx->data + num, inp, len);
|
|
ctx->num = num + len;
|
|
return;
|
|
}
|
|
}
|
|
|
|
rem = len % POLY1305_BLOCK_SIZE;
|
|
len -= rem;
|
|
|
|
if (len >= POLY1305_BLOCK_SIZE) {
|
|
poly1305_blocks(ctx->opaque, inp, len, 1);
|
|
inp += len;
|
|
}
|
|
|
|
if (rem)
|
|
memcpy(ctx->data, inp, rem);
|
|
|
|
ctx->num = rem;
|
|
}
|
|
|
|
void Poly1305_Final(POLY1305 *ctx, unsigned char mac[16])
|
|
{
|
|
#ifdef POLY1305_ASM
|
|
poly1305_blocks_f poly1305_blocks_p = ctx->func.blocks;
|
|
poly1305_emit_f poly1305_emit_p = ctx->func.emit;
|
|
#endif
|
|
size_t num;
|
|
|
|
if ((num = ctx->num)) {
|
|
ctx->data[num++] = 1; /* pad bit */
|
|
while (num < POLY1305_BLOCK_SIZE)
|
|
ctx->data[num++] = 0;
|
|
poly1305_blocks(ctx->opaque, ctx->data, POLY1305_BLOCK_SIZE, 0);
|
|
}
|
|
|
|
poly1305_emit(ctx->opaque, mac, ctx->nonce);
|
|
|
|
/* zero out the state */
|
|
OPENSSL_cleanse(ctx, sizeof(*ctx));
|
|
}
|