From 50269b391fa18556bad72dc8c2fb4e2493a6a054 Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Mon, 10 Jul 2023 14:02:14 -0400 Subject: [PATCH] crypto: switch poly1305 to incremental implementation This code is taken from poly1305-donna-32.h, poly1305-donna.h, poly1305-donna.c from https://github.com/floodyberry/poly1305-donna, commit e6ad6e091d30d7f4ec2d4f978be1fcfcbce72781, with the following modifications: * Coding style (braces around one-line indented if/for loops). * Rename unsigned long (long) to uint32_t and uint64_t. * Rename poly1305_block_size to POLY1305_BLOCK_SIZE. * Adding noexcept to functions. * Merging poly1305_state_internal_t and poly1305_context types. * Merging code from multiple files. * Place all imported code in the poly1305_donna namespace. --- src/crypto/poly1305.cpp | 322 +++++++++++++++++++++++++--------------- src/crypto/poly1305.h | 21 +++ 2 files changed, 227 insertions(+), 116 deletions(-) diff --git a/src/crypto/poly1305.cpp b/src/crypto/poly1305.cpp index 8a86c9601c..c89383c73a 100644 --- a/src/crypto/poly1305.cpp +++ b/src/crypto/poly1305.cpp @@ -2,140 +2,230 @@ // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. -// Based on the public domain implementation by Andrew Moon -// poly1305-donna-unrolled.c from https://github.com/floodyberry/poly1305-donna - #include #include #include -#define mul32x32_64(a,b) ((uint64_t)(a) * (b)) +namespace poly1305_donna { -void poly1305_auth(unsigned char out[POLY1305_TAGLEN], const unsigned char *m, size_t inlen, const unsigned char key[POLY1305_KEYLEN]) { - uint32_t t0,t1,t2,t3; - uint32_t h0,h1,h2,h3,h4; +// Based on the public domain implementation by Andrew Moon +// poly1305-donna-32.h from https://github.com/floodyberry/poly1305-donna + +void poly1305_init(poly1305_context *st, const unsigned char key[32]) noexcept { + /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */ + st->r[0] = (ReadLE32(&key[ 0]) ) & 0x3ffffff; + st->r[1] = (ReadLE32(&key[ 3]) >> 2) & 0x3ffff03; + st->r[2] = (ReadLE32(&key[ 6]) >> 4) & 0x3ffc0ff; + st->r[3] = (ReadLE32(&key[ 9]) >> 6) & 0x3f03fff; + st->r[4] = (ReadLE32(&key[12]) >> 8) & 0x00fffff; + + /* h = 0 */ + st->h[0] = 0; + st->h[1] = 0; + st->h[2] = 0; + st->h[3] = 0; + st->h[4] = 0; + + /* save pad for later */ + st->pad[0] = ReadLE32(&key[16]); + st->pad[1] = ReadLE32(&key[20]); + st->pad[2] = ReadLE32(&key[24]); + st->pad[3] = ReadLE32(&key[28]); + + st->leftover = 0; + st->final = 0; +} + +static void poly1305_blocks(poly1305_context *st, const unsigned char *m, size_t bytes) noexcept { + const uint32_t hibit = (st->final) ? 0 : (1UL << 24); /* 1 << 128 */ uint32_t r0,r1,r2,r3,r4; uint32_t s1,s2,s3,s4; - uint32_t b, nb; - size_t j; - uint64_t t[5]; - uint64_t f0,f1,f2,f3; - uint64_t g0,g1,g2,g3,g4; - uint64_t c; - unsigned char mp[16]; + uint32_t h0,h1,h2,h3,h4; + uint64_t d0,d1,d2,d3,d4; + uint32_t c; - /* clamp key */ - t0 = ReadLE32(key+0); - t1 = ReadLE32(key+4); - t2 = ReadLE32(key+8); - t3 = ReadLE32(key+12); - - /* precompute multipliers */ - r0 = t0 & 0x3ffffff; t0 >>= 26; t0 |= t1 << 6; - r1 = t0 & 0x3ffff03; t1 >>= 20; t1 |= t2 << 12; - r2 = t1 & 0x3ffc0ff; t2 >>= 14; t2 |= t3 << 18; - r3 = t2 & 0x3f03fff; t3 >>= 8; - r4 = t3 & 0x00fffff; + r0 = st->r[0]; + r1 = st->r[1]; + r2 = st->r[2]; + r3 = st->r[3]; + r4 = st->r[4]; s1 = r1 * 5; s2 = r2 * 5; s3 = r3 * 5; s4 = r4 * 5; - /* init state */ - h0 = 0; - h1 = 0; - h2 = 0; - h3 = 0; - h4 = 0; + h0 = st->h[0]; + h1 = st->h[1]; + h2 = st->h[2]; + h3 = st->h[3]; + h4 = st->h[4]; - /* full blocks */ - if (inlen < 16) goto poly1305_donna_atmost15bytes; -poly1305_donna_16bytes: - m += 16; - inlen -= 16; + while (bytes >= POLY1305_BLOCK_SIZE) { + /* h += m[i] */ + h0 += (ReadLE32(m+ 0) ) & 0x3ffffff; + h1 += (ReadLE32(m+ 3) >> 2) & 0x3ffffff; + h2 += (ReadLE32(m+ 6) >> 4) & 0x3ffffff; + h3 += (ReadLE32(m+ 9) >> 6) & 0x3ffffff; + h4 += (ReadLE32(m+12) >> 8) | hibit; - t0 = ReadLE32(m-16); - t1 = ReadLE32(m-12); - t2 = ReadLE32(m-8); - t3 = ReadLE32(m-4); + /* h *= r */ + d0 = ((uint64_t)h0 * r0) + ((uint64_t)h1 * s4) + ((uint64_t)h2 * s3) + ((uint64_t)h3 * s2) + ((uint64_t)h4 * s1); + d1 = ((uint64_t)h0 * r1) + ((uint64_t)h1 * r0) + ((uint64_t)h2 * s4) + ((uint64_t)h3 * s3) + ((uint64_t)h4 * s2); + d2 = ((uint64_t)h0 * r2) + ((uint64_t)h1 * r1) + ((uint64_t)h2 * r0) + ((uint64_t)h3 * s4) + ((uint64_t)h4 * s3); + d3 = ((uint64_t)h0 * r3) + ((uint64_t)h1 * r2) + ((uint64_t)h2 * r1) + ((uint64_t)h3 * r0) + ((uint64_t)h4 * s4); + d4 = ((uint64_t)h0 * r4) + ((uint64_t)h1 * r3) + ((uint64_t)h2 * r2) + ((uint64_t)h3 * r1) + ((uint64_t)h4 * r0); - h0 += t0 & 0x3ffffff; - h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff; - h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff; - h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff; - h4 += (t3 >> 8) | (1 << 24); + /* (partial) h %= p */ + c = (uint32_t)(d0 >> 26); h0 = (uint32_t)d0 & 0x3ffffff; + d1 += c; c = (uint32_t)(d1 >> 26); h1 = (uint32_t)d1 & 0x3ffffff; + d2 += c; c = (uint32_t)(d2 >> 26); h2 = (uint32_t)d2 & 0x3ffffff; + d3 += c; c = (uint32_t)(d3 >> 26); h3 = (uint32_t)d3 & 0x3ffffff; + d4 += c; c = (uint32_t)(d4 >> 26); h4 = (uint32_t)d4 & 0x3ffffff; + h0 += c * 5; c = (h0 >> 26); h0 = h0 & 0x3ffffff; + h1 += c; + m += POLY1305_BLOCK_SIZE; + bytes -= POLY1305_BLOCK_SIZE; + } -poly1305_donna_mul: - t[0] = mul32x32_64(h0,r0) + mul32x32_64(h1,s4) + mul32x32_64(h2,s3) + mul32x32_64(h3,s2) + mul32x32_64(h4,s1); - t[1] = mul32x32_64(h0,r1) + mul32x32_64(h1,r0) + mul32x32_64(h2,s4) + mul32x32_64(h3,s3) + mul32x32_64(h4,s2); - t[2] = mul32x32_64(h0,r2) + mul32x32_64(h1,r1) + mul32x32_64(h2,r0) + mul32x32_64(h3,s4) + mul32x32_64(h4,s3); - t[3] = mul32x32_64(h0,r3) + mul32x32_64(h1,r2) + mul32x32_64(h2,r1) + mul32x32_64(h3,r0) + mul32x32_64(h4,s4); - t[4] = mul32x32_64(h0,r4) + mul32x32_64(h1,r3) + mul32x32_64(h2,r2) + mul32x32_64(h3,r1) + mul32x32_64(h4,r0); - - h0 = (uint32_t)t[0] & 0x3ffffff; c = (t[0] >> 26); - t[1] += c; h1 = (uint32_t)t[1] & 0x3ffffff; b = (uint32_t)(t[1] >> 26); - t[2] += b; h2 = (uint32_t)t[2] & 0x3ffffff; b = (uint32_t)(t[2] >> 26); - t[3] += b; h3 = (uint32_t)t[3] & 0x3ffffff; b = (uint32_t)(t[3] >> 26); - t[4] += b; h4 = (uint32_t)t[4] & 0x3ffffff; b = (uint32_t)(t[4] >> 26); - h0 += b * 5; - - if (inlen >= 16) goto poly1305_donna_16bytes; - - /* final bytes */ -poly1305_donna_atmost15bytes: - if (!inlen) goto poly1305_donna_finish; - - for (j = 0; j < inlen; j++) mp[j] = m[j]; - mp[j++] = 1; - for (; j < 16; j++) mp[j] = 0; - inlen = 0; - - t0 = ReadLE32(mp+0); - t1 = ReadLE32(mp+4); - t2 = ReadLE32(mp+8); - t3 = ReadLE32(mp+12); - - h0 += t0 & 0x3ffffff; - h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff; - h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff; - h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff; - h4 += (t3 >> 8); - - goto poly1305_donna_mul; - -poly1305_donna_finish: - b = h0 >> 26; h0 = h0 & 0x3ffffff; - h1 += b; b = h1 >> 26; h1 = h1 & 0x3ffffff; - h2 += b; b = h2 >> 26; h2 = h2 & 0x3ffffff; - h3 += b; b = h3 >> 26; h3 = h3 & 0x3ffffff; - h4 += b; b = h4 >> 26; h4 = h4 & 0x3ffffff; - h0 += b * 5; b = h0 >> 26; h0 = h0 & 0x3ffffff; - h1 += b; - - g0 = h0 + 5; b = g0 >> 26; g0 &= 0x3ffffff; - g1 = h1 + b; b = g1 >> 26; g1 &= 0x3ffffff; - g2 = h2 + b; b = g2 >> 26; g2 &= 0x3ffffff; - g3 = h3 + b; b = g3 >> 26; g3 &= 0x3ffffff; - g4 = h4 + b - (1 << 26); - - b = (g4 >> 31) - 1; - nb = ~b; - h0 = (h0 & nb) | (g0 & b); - h1 = (h1 & nb) | (g1 & b); - h2 = (h2 & nb) | (g2 & b); - h3 = (h3 & nb) | (g3 & b); - h4 = (h4 & nb) | (g4 & b); - - f0 = ((h0 ) | (h1 << 26)) + (uint64_t)ReadLE32(&key[16]); - f1 = ((h1 >> 6) | (h2 << 20)) + (uint64_t)ReadLE32(&key[20]); - f2 = ((h2 >> 12) | (h3 << 14)) + (uint64_t)ReadLE32(&key[24]); - f3 = ((h3 >> 18) | (h4 << 8)) + (uint64_t)ReadLE32(&key[28]); - - WriteLE32(&out[ 0], f0); f1 += (f0 >> 32); - WriteLE32(&out[ 4], f1); f2 += (f1 >> 32); - WriteLE32(&out[ 8], f2); f3 += (f2 >> 32); - WriteLE32(&out[12], f3); + st->h[0] = h0; + st->h[1] = h1; + st->h[2] = h2; + st->h[3] = h3; + st->h[4] = h4; +} + +void poly1305_finish(poly1305_context *st, unsigned char mac[16]) noexcept { + uint32_t h0,h1,h2,h3,h4,c; + uint32_t g0,g1,g2,g3,g4; + uint64_t f; + uint32_t mask; + + /* process the remaining block */ + if (st->leftover) { + size_t i = st->leftover; + st->buffer[i++] = 1; + for (; i < POLY1305_BLOCK_SIZE; i++) { + st->buffer[i] = 0; + } + st->final = 1; + poly1305_blocks(st, st->buffer, POLY1305_BLOCK_SIZE); + } + + /* fully carry h */ + h0 = st->h[0]; + h1 = st->h[1]; + h2 = st->h[2]; + h3 = st->h[3]; + h4 = st->h[4]; + + c = h1 >> 26; h1 = h1 & 0x3ffffff; + h2 += c; c = h2 >> 26; h2 = h2 & 0x3ffffff; + h3 += c; c = h3 >> 26; h3 = h3 & 0x3ffffff; + h4 += c; c = h4 >> 26; h4 = h4 & 0x3ffffff; + h0 += c * 5; c = h0 >> 26; h0 = h0 & 0x3ffffff; + h1 += c; + + /* compute h + -p */ + g0 = h0 + 5; c = g0 >> 26; g0 &= 0x3ffffff; + g1 = h1 + c; c = g1 >> 26; g1 &= 0x3ffffff; + g2 = h2 + c; c = g2 >> 26; g2 &= 0x3ffffff; + g3 = h3 + c; c = g3 >> 26; g3 &= 0x3ffffff; + g4 = h4 + c - (1UL << 26); + + /* select h if h < p, or h + -p if h >= p */ + mask = (g4 >> ((sizeof(uint32_t) * 8) - 1)) - 1; + g0 &= mask; + g1 &= mask; + g2 &= mask; + g3 &= mask; + g4 &= mask; + mask = ~mask; + h0 = (h0 & mask) | g0; + h1 = (h1 & mask) | g1; + h2 = (h2 & mask) | g2; + h3 = (h3 & mask) | g3; + h4 = (h4 & mask) | g4; + + /* h = h % (2^128) */ + h0 = ((h0 ) | (h1 << 26)) & 0xffffffff; + h1 = ((h1 >> 6) | (h2 << 20)) & 0xffffffff; + h2 = ((h2 >> 12) | (h3 << 14)) & 0xffffffff; + h3 = ((h3 >> 18) | (h4 << 8)) & 0xffffffff; + + /* mac = (h + pad) % (2^128) */ + f = (uint64_t)h0 + st->pad[0] ; h0 = (uint32_t)f; + f = (uint64_t)h1 + st->pad[1] + (f >> 32); h1 = (uint32_t)f; + f = (uint64_t)h2 + st->pad[2] + (f >> 32); h2 = (uint32_t)f; + f = (uint64_t)h3 + st->pad[3] + (f >> 32); h3 = (uint32_t)f; + + WriteLE32(mac + 0, h0); + WriteLE32(mac + 4, h1); + WriteLE32(mac + 8, h2); + WriteLE32(mac + 12, h3); + + /* zero out the state */ + st->h[0] = 0; + st->h[1] = 0; + st->h[2] = 0; + st->h[3] = 0; + st->h[4] = 0; + st->r[0] = 0; + st->r[1] = 0; + st->r[2] = 0; + st->r[3] = 0; + st->r[4] = 0; + st->pad[0] = 0; + st->pad[1] = 0; + st->pad[2] = 0; + st->pad[3] = 0; +} + +void poly1305_update(poly1305_context *st, const unsigned char *m, size_t bytes) noexcept { + size_t i; + + /* handle leftover */ + if (st->leftover) { + size_t want = (POLY1305_BLOCK_SIZE - st->leftover); + if (want > bytes) { + want = bytes; + } + for (i = 0; i < want; i++) { + st->buffer[st->leftover + i] = m[i]; + } + bytes -= want; + m += want; + st->leftover += want; + if (st->leftover < POLY1305_BLOCK_SIZE) return; + poly1305_blocks(st, st->buffer, POLY1305_BLOCK_SIZE); + st->leftover = 0; + } + + /* process full blocks */ + if (bytes >= POLY1305_BLOCK_SIZE) { + size_t want = (bytes & ~(POLY1305_BLOCK_SIZE - 1)); + poly1305_blocks(st, m, want); + m += want; + bytes -= want; + } + + /* store leftover */ + if (bytes) { + for (i = 0; i < bytes; i++) { + st->buffer[st->leftover + i] = m[i]; + } + st->leftover += bytes; + } +} + +} // namespace poly1305_donna + +void poly1305_auth(unsigned char mac[16], const unsigned char *m, size_t bytes, const unsigned char key[32]) { + using namespace poly1305_donna; + poly1305_context ctx; + poly1305_init(&ctx, key); + poly1305_update(&ctx, m, bytes); + poly1305_finish(&ctx, mac); } diff --git a/src/crypto/poly1305.h b/src/crypto/poly1305.h index 650e35bbca..39b69e1cd4 100644 --- a/src/crypto/poly1305.h +++ b/src/crypto/poly1305.h @@ -10,6 +10,27 @@ #define POLY1305_KEYLEN 32 #define POLY1305_TAGLEN 16 +#define POLY1305_BLOCK_SIZE 16 + +namespace poly1305_donna { + +// Based on the public domain implementation by Andrew Moon +// poly1305-donna-32.h from https://github.com/floodyberry/poly1305-donna + +typedef struct { + uint32_t r[5]; + uint32_t h[5]; + uint32_t pad[4]; + size_t leftover; + unsigned char buffer[POLY1305_BLOCK_SIZE]; + unsigned char final; +} poly1305_context; + +void poly1305_init(poly1305_context *st, const unsigned char key[32]) noexcept; +void poly1305_update(poly1305_context *st, const unsigned char *m, size_t bytes) noexcept; +void poly1305_finish(poly1305_context *st, unsigned char mac[16]) noexcept; + +} // namespace poly1305_donna void poly1305_auth(unsigned char out[POLY1305_TAGLEN], const unsigned char *m, size_t inlen, const unsigned char key[POLY1305_KEYLEN]);