didyouexpectthat_zerotierone/node/Poly1305.cpp
2018-01-12 18:20:00 -08:00

636 lines
17 KiB
C++

/*
20080912
D. J. Bernstein
Public domain.
*/
#include "Constants.hpp"
#include "Poly1305.hpp"
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#ifdef __WINDOWS__
#pragma warning(disable: 4146)
#endif
namespace ZeroTier {
#if 0
// "Naive" implementation, which is slower... might still want this on some older
// or weird platforms if the later versions have issues.
static inline void add(unsigned int h[17],const unsigned int c[17])
{
unsigned int j;
unsigned int u;
u = 0;
for (j = 0;j < 17;++j) { u += h[j] + c[j]; h[j] = u & 255; u >>= 8; }
}
static inline void squeeze(unsigned int h[17])
{
unsigned int j;
unsigned int u;
u = 0;
for (j = 0;j < 16;++j) { u += h[j]; h[j] = u & 255; u >>= 8; }
u += h[16]; h[16] = u & 3;
u = 5 * (u >> 2);
for (j = 0;j < 16;++j) { u += h[j]; h[j] = u & 255; u >>= 8; }
u += h[16]; h[16] = u;
}
static const unsigned int minusp[17] = {
5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 252
} ;
static inline void freeze(unsigned int h[17])
{
unsigned int horig[17];
unsigned int j;
unsigned int negative;
for (j = 0;j < 17;++j) horig[j] = h[j];
add(h,minusp);
negative = -(h[16] >> 7);
for (j = 0;j < 17;++j) h[j] ^= negative & (horig[j] ^ h[j]);
}
static inline void mulmod(unsigned int h[17],const unsigned int r[17])
{
unsigned int hr[17];
unsigned int i;
unsigned int j;
unsigned int u;
for (i = 0;i < 17;++i) {
u = 0;
for (j = 0;j <= i;++j) u += h[j] * r[i - j];
for (j = i + 1;j < 17;++j) u += 320 * h[j] * r[i + 17 - j];
hr[i] = u;
}
for (i = 0;i < 17;++i) h[i] = hr[i];
squeeze(h);
}
static inline int crypto_onetimeauth(unsigned char *out,const unsigned char *in,unsigned long long inlen,const unsigned char *k)
{
unsigned int j;
unsigned int r[17];
unsigned int h[17];
unsigned int c[17];
r[0] = k[0];
r[1] = k[1];
r[2] = k[2];
r[3] = k[3] & 15;
r[4] = k[4] & 252;
r[5] = k[5];
r[6] = k[6];
r[7] = k[7] & 15;
r[8] = k[8] & 252;
r[9] = k[9];
r[10] = k[10];
r[11] = k[11] & 15;
r[12] = k[12] & 252;
r[13] = k[13];
r[14] = k[14];
r[15] = k[15] & 15;
r[16] = 0;
for (j = 0;j < 17;++j) h[j] = 0;
while (inlen > 0) {
for (j = 0;j < 17;++j) c[j] = 0;
for (j = 0;(j < 16) && (j < inlen);++j) c[j] = in[j];
c[j] = 1;
in += j; inlen -= j;
add(h,c);
mulmod(h,r);
}
freeze(h);
for (j = 0;j < 16;++j) c[j] = k[j + 16];
c[16] = 0;
add(h,c);
for (j = 0;j < 16;++j) out[j] = h[j];
return 0;
}
void Poly1305::compute(void *auth,const void *data,unsigned int len,const void *key)
throw()
{
crypto_onetimeauth((unsigned char *)auth,(const unsigned char *)data,len,(const unsigned char *)key);
}
#endif
namespace {
typedef struct poly1305_context {
size_t aligner;
unsigned char opaque[136];
} poly1305_context;
#if (defined(_MSC_VER) || defined(__GNUC__)) && (defined(__amd64) || defined(__amd64__) || defined(__x86_64) || defined(__x86_64__) || defined(__AMD64) || defined(__AMD64__) || defined(_M_X64))
//////////////////////////////////////////////////////////////////////////////
// 128-bit implementation for MSC and GCC from Poly1305-donna
#if defined(_MSC_VER)
#include <intrin.h>
typedef struct uint128_t {
unsigned long long lo;
unsigned long long hi;
} uint128_t;
#define MUL(out, x, y) out.lo = _umul128((x), (y), &out.hi)
#define ADD(out, in) { unsigned long long t = out.lo; out.lo += in.lo; out.hi += (out.lo < t) + in.hi; }
#define ADDLO(out, in) { unsigned long long 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)
// #define POLY1305_NOINLINE __declspec(noinline)
#elif defined(__GNUC__)
#if defined(__SIZEOF_INT128__)
typedef unsigned __int128 uint128_t;
#else
typedef unsigned uint128_t __attribute__((mode(TI)));
#endif
#define MUL(out, x, y) out = ((uint128_t)x * y)
#define ADD(out, in) out += in
#define ADDLO(out, in) out += in
#define SHR(in, shift) (unsigned long long)(in >> (shift))
#define LO(in) (unsigned long long)(in)
// #define POLY1305_NOINLINE __attribute__((noinline))
#endif
#define poly1305_block_size 16
/* 17 + sizeof(size_t) + 8*sizeof(unsigned long long) */
typedef struct poly1305_state_internal_t {
unsigned long long r[3];
unsigned long long h[3];
unsigned long long pad[2];
size_t leftover;
unsigned char buffer[poly1305_block_size];
unsigned char final;
} poly1305_state_internal_t;
#if defined(ZT_NO_TYPE_PUNNING) || (__BYTE_ORDER != __LITTLE_ENDIAN)
static inline unsigned long long U8TO64(const unsigned char *p)
{
return
(((unsigned long long)(p[0] & 0xff) ) |
((unsigned long long)(p[1] & 0xff) << 8) |
((unsigned long long)(p[2] & 0xff) << 16) |
((unsigned long long)(p[3] & 0xff) << 24) |
((unsigned long long)(p[4] & 0xff) << 32) |
((unsigned long long)(p[5] & 0xff) << 40) |
((unsigned long long)(p[6] & 0xff) << 48) |
((unsigned long long)(p[7] & 0xff) << 56));
}
#else
#define U8TO64(p) (*reinterpret_cast<const unsigned long long *>(p))
#endif
#if defined(ZT_NO_TYPE_PUNNING) || (__BYTE_ORDER != __LITTLE_ENDIAN)
static inline void U64TO8(unsigned char *p, unsigned long long v)
{
p[0] = (v ) & 0xff;
p[1] = (v >> 8) & 0xff;
p[2] = (v >> 16) & 0xff;
p[3] = (v >> 24) & 0xff;
p[4] = (v >> 32) & 0xff;
p[5] = (v >> 40) & 0xff;
p[6] = (v >> 48) & 0xff;
p[7] = (v >> 56) & 0xff;
}
#else
#define U64TO8(p,v) ((*reinterpret_cast<unsigned long long *>(p)) = (v))
#endif
static inline void
poly1305_init(poly1305_context *ctx, const unsigned char key[32]) {
poly1305_state_internal_t *st = (poly1305_state_internal_t *)ctx;
unsigned long long t0,t1;
/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
t0 = U8TO64(&key[0]);
t1 = U8TO64(&key[8]);
st->r[0] = ( t0 ) & 0xffc0fffffff;
st->r[1] = ((t0 >> 44) | (t1 << 20)) & 0xfffffc0ffff;
st->r[2] = ((t1 >> 24) ) & 0x00ffffffc0f;
/* h = 0 */
st->h[0] = 0;
st->h[1] = 0;
st->h[2] = 0;
/* save pad for later */
st->pad[0] = U8TO64(&key[16]);
st->pad[1] = U8TO64(&key[24]);
st->leftover = 0;
st->final = 0;
}
static inline void
poly1305_blocks(poly1305_state_internal_t *st, const unsigned char *m, size_t bytes) {
const unsigned long long hibit = (st->final) ? 0 : ((unsigned long long)1 << 40); /* 1 << 128 */
unsigned long long r0,r1,r2;
unsigned long long s1,s2;
unsigned long long h0,h1,h2;
unsigned long long c;
uint128_t d0,d1,d2,d;
r0 = st->r[0];
r1 = st->r[1];
r2 = st->r[2];
h0 = st->h[0];
h1 = st->h[1];
h2 = st->h[2];
s1 = r1 * (5 << 2);
s2 = r2 * (5 << 2);
while (bytes >= poly1305_block_size) {
unsigned long long t0,t1;
/* h += m[i] */
t0 = U8TO64(&m[0]);
t1 = U8TO64(&m[8]);
h0 += (( t0 ) & 0xfffffffffff);
h1 += (((t0 >> 44) | (t1 << 20)) & 0xfffffffffff);
h2 += (((t1 >> 24) ) & 0x3ffffffffff) | hibit;
/* h *= r */
MUL(d0, h0, r0); MUL(d, h1, s2); ADD(d0, d); MUL(d, h2, s1); ADD(d0, d);
MUL(d1, h0, r1); MUL(d, h1, r0); ADD(d1, d); MUL(d, h2, s2); ADD(d1, d);
MUL(d2, h0, r2); MUL(d, h1, r1); ADD(d2, d); MUL(d, h2, r0); ADD(d2, d);
/* (partial) h %= p */
c = SHR(d0, 44); h0 = LO(d0) & 0xfffffffffff;
ADDLO(d1, c); c = SHR(d1, 44); h1 = LO(d1) & 0xfffffffffff;
ADDLO(d2, c); c = SHR(d2, 42); h2 = LO(d2) & 0x3ffffffffff;
h0 += c * 5; c = (h0 >> 44); h0 = h0 & 0xfffffffffff;
h1 += c;
m += poly1305_block_size;
bytes -= poly1305_block_size;
}
st->h[0] = h0;
st->h[1] = h1;
st->h[2] = h2;
}
static inline void
poly1305_finish(poly1305_context *ctx, unsigned char mac[16]) {
poly1305_state_internal_t *st = (poly1305_state_internal_t *)ctx;
unsigned long long h0,h1,h2,c;
unsigned long long g0,g1,g2;
unsigned long long t0,t1;
/* process the remaining block */
if (st->leftover) {
size_t i = st->leftover;
st->buffer[i] = 1;
for (i = i + 1; 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];
c = (h1 >> 44); h1 &= 0xfffffffffff;
h2 += c; c = (h2 >> 42); h2 &= 0x3ffffffffff;
h0 += c * 5; c = (h0 >> 44); h0 &= 0xfffffffffff;
h1 += c; c = (h1 >> 44); h1 &= 0xfffffffffff;
h2 += c; c = (h2 >> 42); h2 &= 0x3ffffffffff;
h0 += c * 5; c = (h0 >> 44); h0 &= 0xfffffffffff;
h1 += c;
/* compute h + -p */
g0 = h0 + 5; c = (g0 >> 44); g0 &= 0xfffffffffff;
g1 = h1 + c; c = (g1 >> 44); g1 &= 0xfffffffffff;
g2 = h2 + c - ((unsigned long long)1 << 42);
/* select h if h < p, or h + -p if h >= p */
c = (g2 >> ((sizeof(unsigned long long) * 8) - 1)) - 1;
g0 &= c;
g1 &= c;
g2 &= c;
c = ~c;
h0 = (h0 & c) | g0;
h1 = (h1 & c) | g1;
h2 = (h2 & c) | g2;
/* h = (h + pad) */
t0 = st->pad[0];
t1 = st->pad[1];
h0 += (( t0 ) & 0xfffffffffff) ; c = (h0 >> 44); h0 &= 0xfffffffffff;
h1 += (((t0 >> 44) | (t1 << 20)) & 0xfffffffffff) + c; c = (h1 >> 44); h1 &= 0xfffffffffff;
h2 += (((t1 >> 24) ) & 0x3ffffffffff) + c; h2 &= 0x3ffffffffff;
/* mac = h % (2^128) */
h0 = ((h0 ) | (h1 << 44));
h1 = ((h1 >> 20) | (h2 << 24));
U64TO8(&mac[0], h0);
U64TO8(&mac[8], h1);
/* zero out the state */
st->h[0] = 0;
st->h[1] = 0;
st->h[2] = 0;
st->r[0] = 0;
st->r[1] = 0;
st->r[2] = 0;
st->pad[0] = 0;
st->pad[1] = 0;
}
//////////////////////////////////////////////////////////////////////////////
#else
//////////////////////////////////////////////////////////////////////////////
// More portable 64-bit implementation
#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] = (v ) & 0xff;
p[1] = (v >> 8) & 0xff;
p[2] = (v >> 16) & 0xff;
p[3] = (v >> 24) & 0xff;
}
static inline 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 inline void
poly1305_blocks(poly1305_state_internal_t *st, const unsigned char *m, size_t bytes) {
const unsigned long hibit = (st->final) ? 0 : (1 << 24); /* 1 << 128 */
unsigned long r0,r1,r2,r3,r4;
unsigned long s1,s2,s3,s4;
unsigned long h0,h1,h2,h3,h4;
unsigned long long 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 = ((unsigned long long)h0 * r0) + ((unsigned long long)h1 * s4) + ((unsigned long long)h2 * s3) + ((unsigned long long)h3 * s2) + ((unsigned long long)h4 * s1);
d1 = ((unsigned long long)h0 * r1) + ((unsigned long long)h1 * r0) + ((unsigned long long)h2 * s4) + ((unsigned long long)h3 * s3) + ((unsigned long long)h4 * s2);
d2 = ((unsigned long long)h0 * r2) + ((unsigned long long)h1 * r1) + ((unsigned long long)h2 * r0) + ((unsigned long long)h3 * s4) + ((unsigned long long)h4 * s3);
d3 = ((unsigned long long)h0 * r3) + ((unsigned long long)h1 * r2) + ((unsigned long long)h2 * r1) + ((unsigned long long)h3 * r0) + ((unsigned long long)h4 * s4);
d4 = ((unsigned long long)h0 * r4) + ((unsigned long long)h1 * r3) + ((unsigned long long)h2 * r2) + ((unsigned long long)h3 * r1) + ((unsigned long long)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 inline 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;
unsigned long long 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 - (1 << 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 = (unsigned long long)h0 + st->pad[0] ; h0 = (unsigned long)f;
f = (unsigned long long)h1 + st->pad[1] + (f >> 32); h1 = (unsigned long)f;
f = (unsigned long long)h2 + st->pad[2] + (f >> 32); h2 = (unsigned long)f;
f = (unsigned long long)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;
}
//////////////////////////////////////////////////////////////////////////////
#endif // MSC/GCC or not
static inline void
poly1305_update(poly1305_context *ctx, const unsigned char *m, size_t bytes) {
poly1305_state_internal_t *st = (poly1305_state_internal_t *)ctx;
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;
}
}
} // anonymous namespace
void Poly1305::compute(void *auth,const void *data,unsigned int len,const void *key)
throw()
{
poly1305_context ctx;
poly1305_init(&ctx,reinterpret_cast<const unsigned char *>(key));
poly1305_update(&ctx,reinterpret_cast<const unsigned char *>(data),(size_t)len);
poly1305_finish(&ctx,reinterpret_cast<unsigned char *>(auth));
}
} // namespace ZeroTier