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tls_chacha20.c
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// portable8439 v1.0.1
// Source: https://github.com/DavyLandman/portable8439
// Licensed under CC0-1.0
// Contains poly1305-donna e6ad6e091d30d7f4ec2d4f978be1fcfcbce72781 (Public
// Domain)
#include "tls_chacha20.h"
#include "tls.h"
#if MG_TLS == MG_TLS_BUILTIN
// ******* BEGIN: chacha-portable/chacha-portable.h ********
#if !defined(__cplusplus) && !defined(_MSC_VER) && \
(!defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901L)
#error "C99 or newer required"
#endif
#define CHACHA20_KEY_SIZE (32)
#define CHACHA20_NONCE_SIZE (12)
#if defined(_MSC_VER) || defined(__cplusplus)
// add restrict support
#if (defined(_MSC_VER) && _MSC_VER >= 1900) || defined(__clang__) || \
defined(__GNUC__)
#define restrict __restrict
#else
#define restrict
#endif
#endif
// xor data with a ChaCha20 keystream as per RFC8439
static PORTABLE_8439_DECL void chacha20_xor_stream(
uint8_t *restrict dest, const uint8_t *restrict source, size_t length,
const uint8_t key[CHACHA20_KEY_SIZE],
const uint8_t nonce[CHACHA20_NONCE_SIZE], uint32_t counter);
static PORTABLE_8439_DECL void rfc8439_keygen(
uint8_t poly_key[32], const uint8_t key[CHACHA20_KEY_SIZE],
const uint8_t nonce[CHACHA20_NONCE_SIZE]);
// ******* END: chacha-portable/chacha-portable.h ********
// ******* BEGIN: poly1305-donna/poly1305-donna.h ********
#include <stddef.h>
typedef struct poly1305_context {
size_t aligner;
unsigned char opaque[136];
} poly1305_context;
static PORTABLE_8439_DECL void poly1305_init(poly1305_context *ctx,
const unsigned char key[32]);
static PORTABLE_8439_DECL void poly1305_update(poly1305_context *ctx,
const unsigned char *m,
size_t bytes);
static PORTABLE_8439_DECL void poly1305_finish(poly1305_context *ctx,
unsigned char mac[16]);
// ******* END: poly1305-donna/poly1305-donna.h ********
// ******* BEGIN: chacha-portable.c ********
#include <assert.h>
#include <string.h>
// this is a fresh implementation of chacha20, based on the description in
// rfc8349 it's such a nice compact algorithm that it is easy to do. In
// relationship to other c implementation this implementation:
// - pure c99
// - big & little endian support
// - safe for architectures that don't support unaligned reads
//
// Next to this, we try to be fast as possible without resorting inline
// assembly.
// based on https://sourceforge.net/p/predef/wiki/Endianness/
#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#define __HAVE_LITTLE_ENDIAN 1
#elif defined(__LITTLE_ENDIAN__) || defined(__ARMEL__) || \
defined(__THUMBEL__) || defined(__AARCH64EL__) || defined(_MIPSEL) || \
defined(__MIPSEL) || defined(__MIPSEL__) || defined(__XTENSA_EL__) || \
defined(__AVR__) || defined(LITTLE_ENDIAN)
#define __HAVE_LITTLE_ENDIAN 1
#endif
#ifndef TEST_SLOW_PATH
#if defined(__HAVE_LITTLE_ENDIAN)
#define FAST_PATH
#endif
#endif
#define CHACHA20_STATE_WORDS (16)
#define CHACHA20_BLOCK_SIZE (CHACHA20_STATE_WORDS * sizeof(uint32_t))
#ifdef FAST_PATH
#define store_32_le(target, source) memcpy(&(target), source, sizeof(uint32_t))
#else
#define store_32_le(target, source) \
target = (uint32_t) (source)[0] | ((uint32_t) (source)[1]) << 8 | \
((uint32_t) (source)[2]) << 16 | ((uint32_t) (source)[3]) << 24
#endif
static void initialize_state(uint32_t state[CHACHA20_STATE_WORDS],
const uint8_t key[CHACHA20_KEY_SIZE],
const uint8_t nonce[CHACHA20_NONCE_SIZE],
uint32_t counter) {
#ifdef static_assert
static_assert(sizeof(uint32_t) == 4,
"We don't support systems that do not conform to standard of "
"uint32_t being exact 32bit wide");
#endif
state[0] = 0x61707865;
state[1] = 0x3320646e;
state[2] = 0x79622d32;
state[3] = 0x6b206574;
store_32_le(state[4], key);
store_32_le(state[5], key + 4);
store_32_le(state[6], key + 8);
store_32_le(state[7], key + 12);
store_32_le(state[8], key + 16);
store_32_le(state[9], key + 20);
store_32_le(state[10], key + 24);
store_32_le(state[11], key + 28);
state[12] = counter;
store_32_le(state[13], nonce);
store_32_le(state[14], nonce + 4);
store_32_le(state[15], nonce + 8);
}
#define increment_counter(state) (state)[12]++
// source: http://blog.regehr.org/archives/1063
#define rotl32a(x, n) ((x) << (n)) | ((x) >> (32 - (n)))
#define Qround(a, b, c, d) \
a += b; \
d ^= a; \
d = rotl32a(d, 16); \
c += d; \
b ^= c; \
b = rotl32a(b, 12); \
a += b; \
d ^= a; \
d = rotl32a(d, 8); \
c += d; \
b ^= c; \
b = rotl32a(b, 7);
#define TIMES16(x) \
x(0) x(1) x(2) x(3) x(4) x(5) x(6) x(7) x(8) x(9) x(10) x(11) x(12) x(13) \
x(14) x(15)
static void core_block(const uint32_t *restrict start,
uint32_t *restrict output) {
int i;
// instead of working on the output array,
// we let the compiler allocate 16 local variables on the stack
#define __LV(i) uint32_t __t##i = start[i];
TIMES16(__LV)
#define __Q(a, b, c, d) Qround(__t##a, __t##b, __t##c, __t##d)
for (i = 0; i < 10; i++) {
__Q(0, 4, 8, 12);
__Q(1, 5, 9, 13);
__Q(2, 6, 10, 14);
__Q(3, 7, 11, 15);
__Q(0, 5, 10, 15);
__Q(1, 6, 11, 12);
__Q(2, 7, 8, 13);
__Q(3, 4, 9, 14);
}
#define __FIN(i) output[i] = start[i] + __t##i;
TIMES16(__FIN)
}
#define U8(x) ((uint8_t) ((x) &0xFF))
#ifdef FAST_PATH
#define xor32_le(dst, src, pad) \
uint32_t __value; \
memcpy(&__value, src, sizeof(uint32_t)); \
__value ^= *(pad); \
memcpy(dst, &__value, sizeof(uint32_t));
#else
#define xor32_le(dst, src, pad) \
(dst)[0] = (src)[0] ^ U8(*(pad)); \
(dst)[1] = (src)[1] ^ U8(*(pad) >> 8); \
(dst)[2] = (src)[2] ^ U8(*(pad) >> 16); \
(dst)[3] = (src)[3] ^ U8(*(pad) >> 24);
#endif
#define index8_32(a, ix) ((a) + ((ix) * sizeof(uint32_t)))
#define xor32_blocks(dest, source, pad, words) \
for (i = 0; i < words; i++) { \
xor32_le(index8_32(dest, i), index8_32(source, i), (pad) + i) \
}
static void xor_block(uint8_t *restrict dest, const uint8_t *restrict source,
const uint32_t *restrict pad, unsigned int chunk_size) {
unsigned int i, full_blocks = chunk_size / (unsigned int) sizeof(uint32_t);
// have to be carefull, we are going back from uint32 to uint8, so endianness
// matters again
xor32_blocks(dest, source, pad, full_blocks)
dest += full_blocks * sizeof(uint32_t);
source += full_blocks * sizeof(uint32_t);
pad += full_blocks;
switch (chunk_size % sizeof(uint32_t)) {
case 1:
dest[0] = source[0] ^ U8(*pad);
break;
case 2:
dest[0] = source[0] ^ U8(*pad);
dest[1] = source[1] ^ U8(*pad >> 8);
break;
case 3:
dest[0] = source[0] ^ U8(*pad);
dest[1] = source[1] ^ U8(*pad >> 8);
dest[2] = source[2] ^ U8(*pad >> 16);
break;
}
}
static void chacha20_xor_stream(uint8_t *restrict dest,
const uint8_t *restrict source, size_t length,
const uint8_t key[CHACHA20_KEY_SIZE],
const uint8_t nonce[CHACHA20_NONCE_SIZE],
uint32_t counter) {
uint32_t state[CHACHA20_STATE_WORDS];
uint32_t pad[CHACHA20_STATE_WORDS];
size_t i, b, last_block, full_blocks = length / CHACHA20_BLOCK_SIZE;
initialize_state(state, key, nonce, counter);
for (b = 0; b < full_blocks; b++) {
core_block(state, pad);
increment_counter(state);
xor32_blocks(dest, source, pad, CHACHA20_STATE_WORDS) dest +=
CHACHA20_BLOCK_SIZE;
source += CHACHA20_BLOCK_SIZE;
}
last_block = length % CHACHA20_BLOCK_SIZE;
if (last_block > 0) {
core_block(state, pad);
xor_block(dest, source, pad, (unsigned int) last_block);
}
}
#ifdef FAST_PATH
#define serialize(poly_key, result) memcpy(poly_key, result, 32)
#else
#define store32_le(target, source) \
(target)[0] = U8(*(source)); \
(target)[1] = U8(*(source) >> 8); \
(target)[2] = U8(*(source) >> 16); \
(target)[3] = U8(*(source) >> 24);
#define serialize(poly_key, result) \
for (i = 0; i < 32 / sizeof(uint32_t); i++) { \
store32_le(index8_32(poly_key, i), result + i); \
}
#endif
static void rfc8439_keygen(uint8_t poly_key[32],
const uint8_t key[CHACHA20_KEY_SIZE],
const uint8_t nonce[CHACHA20_NONCE_SIZE]) {
uint32_t state[CHACHA20_STATE_WORDS];
uint32_t result[CHACHA20_STATE_WORDS];
size_t i;
initialize_state(state, key, nonce, 0);
core_block(state, result);
serialize(poly_key, result);
(void) i;
}
// ******* END: chacha-portable.c ********
// ******* BEGIN: poly1305-donna.c ********
/* auto detect between 32bit / 64bit */
#if /* uint128 available on 64bit system*/ \
(defined(__SIZEOF_INT128__) && \
defined(__LP64__)) /* MSVC 64bit compiler */ \
|| (defined(_MSC_VER) && defined(_M_X64)) /* gcc >= 4.4 64bit */ \
|| (defined(__GNUC__) && defined(__LP64__) && \
((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 4))))
#define __GUESS64
#else
#define __GUESS32
#endif
#if defined(POLY1305_8BIT)
/*
poly1305 implementation using 8 bit * 8 bit = 16 bit multiplication and
32 bit addition
based on the public domain reference version in supercop by djb
static */
#if defined(_MSC_VER) && _MSC_VER < 1700
#define POLY1305_NOINLINE
#elif defined(_MSC_VER)
#define POLY1305_NOINLINE __declspec(noinline)
#elif defined(__GNUC__)
#define POLY1305_NOINLINE __attribute__((noinline))
#else
#define POLY1305_NOINLINE
#endif
#define poly1305_block_size 16
/* 17 + sizeof(size_t) + 51*sizeof(unsigned char) */
typedef struct poly1305_state_internal_t {
unsigned char buffer[poly1305_block_size];
size_t leftover;
unsigned char h[17];
unsigned char r[17];
unsigned char pad[17];
unsigned char final;
} poly1305_state_internal_t;
static void poly1305_init(poly1305_context *ctx, const unsigned char key[32]) {
poly1305_state_internal_t *st = (poly1305_state_internal_t *) ctx;
size_t i;
st->leftover = 0;
/* h = 0 */
for (i = 0; i < 17; i++) st->h[i] = 0;
/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
st->r[0] = key[0] & 0xff;
st->r[1] = key[1] & 0xff;
st->r[2] = key[2] & 0xff;
st->r[3] = key[3] & 0x0f;
st->r[4] = key[4] & 0xfc;
st->r[5] = key[5] & 0xff;
st->r[6] = key[6] & 0xff;
st->r[7] = key[7] & 0x0f;
st->r[8] = key[8] & 0xfc;
st->r[9] = key[9] & 0xff;
st->r[10] = key[10] & 0xff;
st->r[11] = key[11] & 0x0f;
st->r[12] = key[12] & 0xfc;
st->r[13] = key[13] & 0xff;
st->r[14] = key[14] & 0xff;
st->r[15] = key[15] & 0x0f;
st->r[16] = 0;
/* save pad for later */
for (i = 0; i < 16; i++) st->pad[i] = key[i + 16];
st->pad[16] = 0;
st->final = 0;
}
static void poly1305_add(unsigned char h[17], const unsigned char c[17]) {
unsigned short u;
unsigned int i;
for (u = 0, i = 0; i < 17; i++) {
u += (unsigned short) h[i] + (unsigned short) c[i];
h[i] = (unsigned char) u & 0xff;
u >>= 8;
}
}
static void poly1305_squeeze(unsigned char h[17], unsigned long hr[17]) {
unsigned long u;
unsigned int i;
u = 0;
for (i = 0; i < 16; i++) {
u += hr[i];
h[i] = (unsigned char) u & 0xff;
u >>= 8;
}
u += hr[16];
h[16] = (unsigned char) u & 0x03;
u >>= 2;
u += (u << 2); /* u *= 5; */
for (i = 0; i < 16; i++) {
u += h[i];
h[i] = (unsigned char) u & 0xff;
u >>= 8;
}
h[16] += (unsigned char) u;
}
static void poly1305_freeze(unsigned char h[17]) {
const unsigned char minusp[17] = {0x05, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0xfc};
unsigned char horig[17], negative;
unsigned int i;
/* compute h + -p */
for (i = 0; i < 17; i++) horig[i] = h[i];
poly1305_add(h, minusp);
/* select h if h < p, or h + -p if h >= p */
negative = -(h[16] >> 7);
for (i = 0; i < 17; i++) h[i] ^= negative & (horig[i] ^ h[i]);
}
static void poly1305_blocks(poly1305_state_internal_t *st,
const unsigned char *m, size_t bytes) {
const unsigned char hibit = st->final ^ 1; /* 1 << 128 */
while (bytes >= poly1305_block_size) {
unsigned long hr[17], u;
unsigned char c[17];
unsigned int i, j;
/* h += m */
for (i = 0; i < 16; i++) c[i] = m[i];
c[16] = hibit;
poly1305_add(st->h, c);
/* h *= r */
for (i = 0; i < 17; i++) {
u = 0;
for (j = 0; j <= i; j++) {
u += (unsigned short) st->h[j] * st->r[i - j];
}
for (j = i + 1; j < 17; j++) {
unsigned long v = (unsigned short) st->h[j] * st->r[i + 17 - j];
v = ((v << 8) + (v << 6)); /* v *= (5 << 6); */
u += v;
}
hr[i] = u;
}
/* (partial) h %= p */
poly1305_squeeze(st->h, hr);
m += poly1305_block_size;
bytes -= poly1305_block_size;
}
}
static POLY1305_NOINLINE void poly1305_finish(poly1305_context *ctx,
unsigned char mac[16]) {
poly1305_state_internal_t *st = (poly1305_state_internal_t *) ctx;
size_t i;
/* 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 reduce h */
poly1305_freeze(st->h);
/* h = (h + pad) % (1 << 128) */
poly1305_add(st->h, st->pad);
for (i = 0; i < 16; i++) mac[i] = st->h[i];
/* zero out the state */
for (i = 0; i < 17; i++) st->h[i] = 0;
for (i = 0; i < 17; i++) st->r[i] = 0;
for (i = 0; i < 17; i++) st->pad[i] = 0;
}
#elif defined(POLY1305_16BIT)
/*
poly1305 implementation using 16 bit * 16 bit = 32 bit multiplication
and 32 bit addition static */
#if defined(_MSC_VER) && _MSC_VER < 1700
#define POLY1305_NOINLINE
#elif defined(_MSC_VER)
#define POLY1305_NOINLINE __declspec(noinline)
#elif defined(__GNUC__)
#define POLY1305_NOINLINE __attribute__((noinline))
#else
#define POLY1305_NOINLINE
#endif
#define poly1305_block_size 16
/* 17 + sizeof(size_t) + 18*sizeof(unsigned short) */
typedef struct poly1305_state_internal_t {
unsigned char buffer[poly1305_block_size];
size_t leftover;
unsigned short r[10];
unsigned short h[10];
unsigned short pad[8];
unsigned char final;
} poly1305_state_internal_t;
/* interpret two 8 bit unsigned integers as a 16 bit unsigned integer in little
* endian */
static unsigned short U8TO16(const unsigned char *p) {
return (((unsigned short) (p[0] & 0xff)) |
((unsigned short) (p[1] & 0xff) << 8));
}
/* store a 16 bit unsigned integer as two 8 bit unsigned integers in little
* endian */
static void U16TO8(unsigned char *p, unsigned short v) {
p[0] = (v) &0xff;
p[1] = (v >> 8) & 0xff;
}
static void poly1305_init(poly1305_context *ctx, const unsigned char key[32]) {
poly1305_state_internal_t *st = (poly1305_state_internal_t *) ctx;
unsigned short t0, t1, t2, t3, t4, t5, t6, t7;
size_t i;
/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
t0 = U8TO16(&key[0]);
st->r[0] = (t0) &0x1fff;
t1 = U8TO16(&key[2]);
st->r[1] = ((t0 >> 13) | (t1 << 3)) & 0x1fff;
t2 = U8TO16(&key[4]);
st->r[2] = ((t1 >> 10) | (t2 << 6)) & 0x1f03;
t3 = U8TO16(&key[6]);
st->r[3] = ((t2 >> 7) | (t3 << 9)) & 0x1fff;
t4 = U8TO16(&key[8]);
st->r[4] = ((t3 >> 4) | (t4 << 12)) & 0x00ff;
st->r[5] = ((t4 >> 1)) & 0x1ffe;
t5 = U8TO16(&key[10]);
st->r[6] = ((t4 >> 14) | (t5 << 2)) & 0x1fff;
t6 = U8TO16(&key[12]);
st->r[7] = ((t5 >> 11) | (t6 << 5)) & 0x1f81;
t7 = U8TO16(&key[14]);
st->r[8] = ((t6 >> 8) | (t7 << 8)) & 0x1fff;
st->r[9] = ((t7 >> 5)) & 0x007f;
/* h = 0 */
for (i = 0; i < 10; i++) st->h[i] = 0;
/* save pad for later */
for (i = 0; i < 8; i++) st->pad[i] = U8TO16(&key[16 + (2 * i)]);
st->leftover = 0;
st->final = 0;
}
static void poly1305_blocks(poly1305_state_internal_t *st,
const unsigned char *m, size_t bytes) {
const unsigned short hibit = (st->final) ? 0 : (1 << 11); /* 1 << 128 */
unsigned short t0, t1, t2, t3, t4, t5, t6, t7;
unsigned long d[10];
unsigned long c;
while (bytes >= poly1305_block_size) {
size_t i, j;
/* h += m[i] */
t0 = U8TO16(&m[0]);
st->h[0] += (t0) &0x1fff;
t1 = U8TO16(&m[2]);
st->h[1] += ((t0 >> 13) | (t1 << 3)) & 0x1fff;
t2 = U8TO16(&m[4]);
st->h[2] += ((t1 >> 10) | (t2 << 6)) & 0x1fff;
t3 = U8TO16(&m[6]);
st->h[3] += ((t2 >> 7) | (t3 << 9)) & 0x1fff;
t4 = U8TO16(&m[8]);
st->h[4] += ((t3 >> 4) | (t4 << 12)) & 0x1fff;
st->h[5] += ((t4 >> 1)) & 0x1fff;
t5 = U8TO16(&m[10]);
st->h[6] += ((t4 >> 14) | (t5 << 2)) & 0x1fff;
t6 = U8TO16(&m[12]);
st->h[7] += ((t5 >> 11) | (t6 << 5)) & 0x1fff;
t7 = U8TO16(&m[14]);
st->h[8] += ((t6 >> 8) | (t7 << 8)) & 0x1fff;
st->h[9] += ((t7 >> 5)) | hibit;
/* h *= r, (partial) h %= p */
for (i = 0, c = 0; i < 10; i++) {
d[i] = c;
for (j = 0; j < 10; j++) {
d[i] += (unsigned long) st->h[j] *
((j <= i) ? st->r[i - j] : (5 * st->r[i + 10 - j]));
/* Sum(h[i] * r[i] * 5) will overflow slightly above 6 products with an
* unclamped r, so carry at 5 */
if (j == 4) {
c = (d[i] >> 13);
d[i] &= 0x1fff;
}
}
c += (d[i] >> 13);
d[i] &= 0x1fff;
}
c = ((c << 2) + c); /* c *= 5 */
c += d[0];
d[0] = ((unsigned short) c & 0x1fff);
c = (c >> 13);
d[1] += c;
for (i = 0; i < 10; i++) st->h[i] = (unsigned short) d[i];
m += poly1305_block_size;
bytes -= poly1305_block_size;
}
}
static POLY1305_NOINLINE void poly1305_finish(poly1305_context *ctx,
unsigned char mac[16]) {
poly1305_state_internal_t *st = (poly1305_state_internal_t *) ctx;
unsigned short c;
unsigned short g[10];
unsigned short mask;
unsigned long f;
size_t i;
/* 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 */
c = st->h[1] >> 13;
st->h[1] &= 0x1fff;
for (i = 2; i < 10; i++) {
st->h[i] += c;
c = st->h[i] >> 13;
st->h[i] &= 0x1fff;
}
st->h[0] += (c * 5);
c = st->h[0] >> 13;
st->h[0] &= 0x1fff;
st->h[1] += c;
c = st->h[1] >> 13;
st->h[1] &= 0x1fff;
st->h[2] += c;
/* compute h + -p */
g[0] = st->h[0] + 5;
c = g[0] >> 13;
g[0] &= 0x1fff;
for (i = 1; i < 10; i++) {
g[i] = st->h[i] + c;
c = g[i] >> 13;
g[i] &= 0x1fff;
}
/* select h if h < p, or h + -p if h >= p */
mask = (c ^ 1) - 1;
for (i = 0; i < 10; i++) g[i] &= mask;
mask = ~mask;
for (i = 0; i < 10; i++) st->h[i] = (st->h[i] & mask) | g[i];
/* h = h % (2^128) */
st->h[0] = ((st->h[0]) | (st->h[1] << 13)) & 0xffff;
st->h[1] = ((st->h[1] >> 3) | (st->h[2] << 10)) & 0xffff;
st->h[2] = ((st->h[2] >> 6) | (st->h[3] << 7)) & 0xffff;
st->h[3] = ((st->h[3] >> 9) | (st->h[4] << 4)) & 0xffff;
st->h[4] = ((st->h[4] >> 12) | (st->h[5] << 1) | (st->h[6] << 14)) & 0xffff;
st->h[5] = ((st->h[6] >> 2) | (st->h[7] << 11)) & 0xffff;
st->h[6] = ((st->h[7] >> 5) | (st->h[8] << 8)) & 0xffff;
st->h[7] = ((st->h[8] >> 8) | (st->h[9] << 5)) & 0xffff;
/* mac = (h + pad) % (2^128) */
f = (unsigned long) st->h[0] + st->pad[0];
st->h[0] = (unsigned short) f;
for (i = 1; i < 8; i++) {
f = (unsigned long) st->h[i] + st->pad[i] + (f >> 16);
st->h[i] = (unsigned short) f;
}
for (i = 0; i < 8; i++) U16TO8(mac + (i * 2), st->h[i]);
/* zero out the state */
for (i = 0; i < 10; i++) st->h[i] = 0;
for (i = 0; i < 10; i++) st->r[i] = 0;
for (i = 0; i < 8; i++) st->pad[i] = 0;
}
#elif defined(POLY1305_32BIT) || \
(!defined(POLY1305_64BIT) && defined(__GUESS32))
/*
poly1305 implementation using 32 bit * 32 bit = 64 bit multiplication
and 64 bit addition static */
#if defined(_MSC_VER) && _MSC_VER < 1700
#define POLY1305_NOINLINE
#elif defined(_MSC_VER)
#define POLY1305_NOINLINE __declspec(noinline)
#elif defined(__GNUC__)
#define POLY1305_NOINLINE __attribute__((noinline))
#else
#define POLY1305_NOINLINE
#endif
#define poly1305_block_size 16
/* 17 + sizeof(size_t) + 14*sizeof(unsigned long) */
typedef struct poly1305_state_internal_t {
unsigned long r[5];
unsigned long h[5];
unsigned long pad[4];
size_t leftover;
unsigned char buffer[poly1305_block_size];
unsigned char final;
} poly1305_state_internal_t;
/* interpret four 8 bit unsigned integers as a 32 bit unsigned integer in little
* endian */
static unsigned long U8TO32(const unsigned char *p) {
return (((unsigned long) (p[0] & 0xff)) |
((unsigned long) (p[1] & 0xff) << 8) |
((unsigned long) (p[2] & 0xff) << 16) |
((unsigned long) (p[3] & 0xff) << 24));
}
/* store a 32 bit unsigned integer as four 8 bit unsigned integers in little
* endian */
static void U32TO8(unsigned char *p, unsigned long 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);
}
static void poly1305_init(poly1305_context *ctx, const unsigned char key[32]) {
poly1305_state_internal_t *st = (poly1305_state_internal_t *) ctx;
/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
st->r[0] = (U8TO32(&key[0])) & 0x3ffffff;
st->r[1] = (U8TO32(&key[3]) >> 2) & 0x3ffff03;
st->r[2] = (U8TO32(&key[6]) >> 4) & 0x3ffc0ff;
st->r[3] = (U8TO32(&key[9]) >> 6) & 0x3f03fff;
st->r[4] = (U8TO32(&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] = U8TO32(&key[16]);
st->pad[1] = U8TO32(&key[20]);
st->pad[2] = U8TO32(&key[24]);
st->pad[3] = U8TO32(&key[28]);
st->leftover = 0;
st->final = 0;
}
static void poly1305_blocks(poly1305_state_internal_t *st,
const unsigned char *m, size_t bytes) {
const unsigned long hibit = (st->final) ? 0 : (1UL << 24); /* 1 << 128 */
unsigned long r0, r1, r2, r3, r4;
unsigned long s1, s2, s3, s4;
unsigned long h0, h1, h2, h3, h4;
uint64_t d0, d1, d2, d3, d4;
unsigned long c;
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;
h0 = st->h[0];
h1 = st->h[1];
h2 = st->h[2];
h3 = st->h[3];
h4 = st->h[4];
while (bytes >= poly1305_block_size) {
/* h += m[i] */
h0 += (U8TO32(m + 0)) & 0x3ffffff;
h1 += (U8TO32(m + 3) >> 2) & 0x3ffffff;
h2 += (U8TO32(m + 6) >> 4) & 0x3ffffff;
h3 += (U8TO32(m + 9) >> 6) & 0x3ffffff;
h4 += (U8TO32(m + 12) >> 8) | hibit;
/* 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);
/* (partial) h %= p */
c = (unsigned long) (d0 >> 26);
h0 = (unsigned long) d0 & 0x3ffffff;
d1 += c;
c = (unsigned long) (d1 >> 26);
h1 = (unsigned long) d1 & 0x3ffffff;
d2 += c;
c = (unsigned long) (d2 >> 26);
h2 = (unsigned long) d2 & 0x3ffffff;
d3 += c;
c = (unsigned long) (d3 >> 26);
h3 = (unsigned long) d3 & 0x3ffffff;
d4 += c;
c = (unsigned long) (d4 >> 26);
h4 = (unsigned long) d4 & 0x3ffffff;
h0 += c * 5;
c = (h0 >> 26);
h0 = h0 & 0x3ffffff;
h1 += c;
m += poly1305_block_size;
bytes -= poly1305_block_size;
}
st->h[0] = h0;
st->h[1] = h1;
st->h[2] = h2;
st->h[3] = h3;
st->h[4] = h4;
}
static POLY1305_NOINLINE void poly1305_finish(poly1305_context *ctx,
unsigned char mac[16]) {
poly1305_state_internal_t *st = (poly1305_state_internal_t *) ctx;
unsigned long h0, h1, h2, h3, h4, c;
unsigned long g0, g1, g2, g3, g4;
uint64_t f;
unsigned long 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(unsigned long) * 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 = (unsigned long) f;
f = (uint64_t) h1 + st->pad[1] + (f >> 32);
h1 = (unsigned long) f;
f = (uint64_t) h2 + st->pad[2] + (f >> 32);
h2 = (unsigned long) f;
f = (uint64_t) h3 + st->pad[3] + (f >> 32);
h3 = (unsigned long) f;
U32TO8(mac + 0, h0);
U32TO8(mac + 4, h1);
U32TO8(mac + 8, h2);
U32TO8(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;
}
#else
/*
poly1305 implementation using 64 bit * 64 bit = 128 bit multiplication
and 128 bit addition static */
#if defined(_MSC_VER)
typedef struct uint128_t {
uint64_t lo;
uint64_t hi;
} uint128_t;
#define MUL128(out, x, y) out.lo = _umul128((x), (y), &out.hi)
#define ADD(out, in) \
{ \
uint64_t t = out.lo; \
out.lo += in.lo; \
out.hi += (out.lo < t) + in.hi; \
}
#define ADDLO(out, in) \
{ \
uint64_t t = out.lo; \
out.lo += in; \
out.hi += (out.lo < t); \
}
#define SHR(in, shift) (__shiftright128(in.lo, in.hi, (shift)))
#define LO(in) (in.lo)
#if defined(_MSC_VER) && _MSC_VER < 1700
#define POLY1305_NOINLINE
#else
#define POLY1305_NOINLINE __declspec(noinline)
#endif
#elif defined(__GNUC__)
#if defined(__SIZEOF_INT128__)
// Get rid of GCC warning "ISO C does not support '__int128' types"
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpedantic"
typedef unsigned __int128 uint128_t;
#pragma GCC diagnostic pop
#else
typedef unsigned uint128_t __attribute__((mode(TI)));
#endif
#define MUL128(out, x, y) out = ((uint128_t) x * y)
#define ADD(out, in) out += in
#define ADDLO(out, in) out += in
#define SHR(in, shift) (uint64_t)(in >> (shift))
#define LO(in) (uint64_t)(in)
#define POLY1305_NOINLINE __attribute__((noinline))
#endif
#define poly1305_block_size 16
/* 17 + sizeof(size_t) + 8*sizeof(uint64_t) */
typedef struct poly1305_state_internal_t {
uint64_t r[3];
uint64_t h[3];
uint64_t pad[2];
size_t leftover;
unsigned char buffer[poly1305_block_size];
unsigned char final;
} poly1305_state_internal_t;
/* interpret eight 8 bit unsigned integers as a 64 bit unsigned integer in
* little endian */
static uint64_t U8TO64(const unsigned char *p) {