poly1305.cpp
// poly1305.cpp - written and placed in the public domain by Jeffrey Walton and Jean-Pierre Munch
// Based on Andy Polyakov's Base-2^26 scalar multiplication implementation.
// For more information, see https://www.openssl.org/~appro/cryptogams/.
// Copyright (c) 2006-2017, CRYPTOGAMS by <appro@openssl.org>
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// * Redistributions of source code must retain copyright notices,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials
// provided with the distribution.
// * Neither the name of the CRYPTOGAMS nor the names of its copyright
// holder and contributors may be used to endorse or promote products
// derived from this software without specific prior written permission.
#include "pch.h"
#include "cryptlib.h"
#include "poly1305.h"
#include "aes.h"
#include "cpu.h"
////////////////////////////// Common Poly1305 //////////////////////////////
ANONYMOUS_NAMESPACE_BEGIN
using namespace CryptoPP;
inline word32 CONSTANT_TIME_CARRY(word32 a, word32 b)
{
return ((a ^ ((a ^ b) | ((a - b) ^ b))) >> (sizeof(a) * 8 - 1));
}
void Poly1305_HashBlocks(word32 h[5], word32 r[4], const byte *input, size_t length, word32 padbit)
{
word32 r0, r1, r2, r3;
word32 s1, s2, s3;
word32 h0, h1, h2, h3, h4, c;
word64 d0, d1, d2, d3;
r0 = r[0]; r1 = r[1];
r2 = r[2]; r3 = r[3];
s1 = r1 + (r1 >> 2);
s2 = r2 + (r2 >> 2);
s3 = r3 + (r3 >> 2);
h0 = h[0]; h1 = h[1]; h2 = h[2];
h3 = h[3]; h4 = h[4];
while (length >= 16)
{
// h += m[i]
h0 = (word32)(d0 = (word64)h0 + GetWord<word32>(false, LITTLE_ENDIAN_ORDER, input + 0));
h1 = (word32)(d1 = (word64)h1 + (d0 >> 32) + GetWord<word32>(false, LITTLE_ENDIAN_ORDER, input + 4));
h2 = (word32)(d2 = (word64)h2 + (d1 >> 32) + GetWord<word32>(false, LITTLE_ENDIAN_ORDER, input + 8));
h3 = (word32)(d3 = (word64)h3 + (d2 >> 32) + GetWord<word32>(false, LITTLE_ENDIAN_ORDER, input + 12));
h4 += (word32)(d3 >> 32) + padbit;
// h *= r "%" p
d0 = ((word64)h0 * r0) +
((word64)h1 * s3) +
((word64)h2 * s2) +
((word64)h3 * s1);
d1 = ((word64)h0 * r1) +
((word64)h1 * r0) +
((word64)h2 * s3) +
((word64)h3 * s2) +
(h4 * s1);
d2 = ((word64)h0 * r2) +
((word64)h1 * r1) +
((word64)h2 * r0) +
((word64)h3 * s3) +
(h4 * s2);
d3 = ((word64)h0 * r3) +
((word64)h1 * r2) +
((word64)h2 * r1) +
((word64)h3 * r0) +
(h4 * s3);
h4 = (h4 * r0);
// a) h4:h0 = h4<<128 + d3<<96 + d2<<64 + d1<<32 + d0
h0 = (word32)d0;
h1 = (word32)(d1 += d0 >> 32);
h2 = (word32)(d2 += d1 >> 32);
h3 = (word32)(d3 += d2 >> 32);
h4 += (word32)(d3 >> 32);
// b) (h4:h0 += (h4:h0>>130) * 5) %= 2^130
c = (h4 >> 2) + (h4 & ~3U);
h4 &= 3;
h0 += c;
h1 += (c = CONSTANT_TIME_CARRY(h0,c));
h2 += (c = CONSTANT_TIME_CARRY(h1,c));
h3 += (c = CONSTANT_TIME_CARRY(h2,c));
h4 += CONSTANT_TIME_CARRY(h3,c);
input += 16;
length -= 16;
}
h[0] = h0; h[1] = h1; h[2] = h2;
h[3] = h3; h[4] = h4;
}
void Poly1305_HashFinal(word32 h[5], word32 n[4], byte *mac, size_t size)
{
word32 h0, h1, h2, h3, h4;
word32 g0, g1, g2, g3, g4;
word32 mask;
word64 t;
h0 = h[0];
h1 = h[1];
h2 = h[2];
h3 = h[3];
h4 = h[4];
// compare to modulus by computing h + -p
g0 = (word32)(t = (word64)h0 + 5);
g1 = (word32)(t = (word64)h1 + (t >> 32));
g2 = (word32)(t = (word64)h2 + (t >> 32));
g3 = (word32)(t = (word64)h3 + (t >> 32));
g4 = h4 + (word32)(t >> 32);
// if there was carry into 131st bit, h3:h0 = g3:g0
mask = 0 - (g4 >> 2);
g0 &= mask; g1 &= mask;
g2 &= mask; g3 &= mask;
mask = ~mask;
h0 = (h0 & mask) | g0; h1 = (h1 & mask) | g1;
h2 = (h2 & mask) | g2; h3 = (h3 & mask) | g3;
// mac = (h + nonce) % (2^128)
h0 = (word32)(t = (word64)h0 + n[0]);
h1 = (word32)(t = (word64)h1 + (t >> 32) + n[1]);
h2 = (word32)(t = (word64)h2 + (t >> 32) + n[2]);
h3 = (word32)(t = (word64)h3 + (t >> 32) + n[3]);
if (size >= 16)
{
PutWord<word32>(false, LITTLE_ENDIAN_ORDER, mac + 0, h0);
PutWord<word32>(false, LITTLE_ENDIAN_ORDER, mac + 4, h1);
PutWord<word32>(false, LITTLE_ENDIAN_ORDER, mac + 8, h2);
PutWord<word32>(false, LITTLE_ENDIAN_ORDER, mac + 12, h3);
}
else
{
FixedSizeAlignedSecBlock<byte, 16> m;
PutWord<word32>(false, LITTLE_ENDIAN_ORDER, m + 0, h0);
PutWord<word32>(false, LITTLE_ENDIAN_ORDER, m + 4, h1);
PutWord<word32>(false, LITTLE_ENDIAN_ORDER, m + 8, h2);
PutWord<word32>(false, LITTLE_ENDIAN_ORDER, m + 12, h3);
std::memcpy(mac, m, size);
}
}
ANONYMOUS_NAMESPACE_END
NAMESPACE_BEGIN(CryptoPP)
////////////////////////////// Bernstein Poly1305 //////////////////////////////
// TODO: No longer needed. Remove at next major version bump
template <class T>
void Poly1305_Base<T>::HashBlocks(const byte *input, size_t length, word32 padbit) {
CRYPTOPP_UNUSED(input); CRYPTOPP_UNUSED(length); CRYPTOPP_UNUSED(padbit);
CRYPTOPP_ASSERT(0);
}
// TODO: No longer needed. Remove at next major version bump
template <class T>
void Poly1305_Base<T>::HashFinal(byte *mac, size_t length) {
CRYPTOPP_UNUSED(mac); CRYPTOPP_UNUSED(length);
CRYPTOPP_ASSERT(0);
}
template <class T>
std::string Poly1305_Base<T>::AlgorithmProvider() const
{
return m_cipher.AlgorithmProvider();
}
template <class T>
void Poly1305_Base<T>::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &params)
{
CRYPTOPP_ASSERT(key && length >= 32);
// key is {k,r} pair. k is AES key, r is the additional key that gets clamped
length = SaturatingSubtract(length, (unsigned)BLOCKSIZE);
m_cipher.SetKey(key, length);
key += length;
// Rbar is clamped and little endian
m_r[0] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 0) & 0x0fffffff;
m_r[1] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 4) & 0x0ffffffc;
m_r[2] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 8) & 0x0ffffffc;
m_r[3] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 12) & 0x0ffffffc;
// Mark the nonce as dirty, meaning we need a new one
m_used = true;
ConstByteArrayParameter t;
if (params.GetValue(Name::IV(), t) && t.begin() && t.size())
{
CRYPTOPP_ASSERT(t.size() == m_nk.size());
Resynchronize(t.begin(), (int)t.size());
}
Restart();
}
template <class T>
void Poly1305_Base<T>::Update(const byte *input, size_t length)
{
CRYPTOPP_ASSERT((input && length) || !length);
if (!length) return;
size_t rem, num = m_idx;
if (num)
{
rem = BLOCKSIZE - num;
if (length >= rem)
{
// Process
memcpy_s(m_acc + num, BLOCKSIZE - num, input, rem);
Poly1305_HashBlocks(m_h, m_r, m_acc, BLOCKSIZE, 1);
input += rem; length -= rem;
}
else
{
// Accumulate
memcpy_s(m_acc + num, BLOCKSIZE - num, input, length);
m_idx = num + length;
return;
}
}
rem = length % BLOCKSIZE;
length -= rem;
if (length >= BLOCKSIZE) {
Poly1305_HashBlocks(m_h, m_r, input, length, 1);
input += length;
}
if (rem)
std::memcpy(m_acc, input, rem);
m_idx = rem;
}
template <class T>
void Poly1305_Base<T>::TruncatedFinal(byte *mac, size_t size)
{
CRYPTOPP_ASSERT(mac); // Pointer is valid
CRYPTOPP_ASSERT(!m_used); // Nonce is fresh
ThrowIfInvalidTruncatedSize(size);
size_t num = m_idx;
if (num)
{
m_acc[num++] = 1; /* pad bit */
while (num < BLOCKSIZE)
m_acc[num++] = 0;
Poly1305_HashBlocks(m_h, m_r, m_acc, BLOCKSIZE, 0);
}
Poly1305_HashFinal(m_h, m_n, mac, size);
// Restart
m_used = true;
Restart();
}
template <class T>
void Poly1305_Base<T>::Resynchronize(const byte *nonce, int nonceLength)
{
CRYPTOPP_ASSERT(nonceLength == -1 || nonceLength == (int)BLOCKSIZE);
if (nonceLength == -1) { nonceLength = BLOCKSIZE; }
// Encrypt the nonce, stash in m_nk
m_cipher.ProcessBlock(nonce, m_nk.begin());
m_n[0] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, m_nk + 0);
m_n[1] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, m_nk + 4);
m_n[2] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, m_nk + 8);
m_n[3] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, m_nk + 12);
// Mark nonce as unused, meaning it is fresh
m_used = false;
}
template <class T>
void Poly1305_Base<T>::GetNextIV(RandomNumberGenerator &rng, byte *iv)
{
rng.GenerateBlock(iv, BLOCKSIZE);
}
template <class T>
void Poly1305_Base<T>::Restart()
{
m_h[0] = m_h[1] = m_h[2] = m_h[3] = m_h[4] = 0;
m_idx = 0;
}
////////////////////////////// IETF Poly1305 //////////////////////////////
void Poly1305TLS_Base::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &params)
{
CRYPTOPP_UNUSED(params); CRYPTOPP_UNUSED(length);
CRYPTOPP_ASSERT(key && length >= 32);
// key is {r,s} pair. r is the additional key that gets clamped, s is the nonce.
m_r[0] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 0) & 0x0fffffff;
m_r[1] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 4) & 0x0ffffffc;
m_r[2] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 8) & 0x0ffffffc;
m_r[3] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 12) & 0x0ffffffc;
key += 16;
m_n[0] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 0);
m_n[1] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 4);
m_n[2] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 8);
m_n[3] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, key + 12);
Restart();
}
void Poly1305TLS_Base::Update(const byte *input, size_t length)
{
CRYPTOPP_ASSERT((input && length) || !length);
if (!length) return;
size_t rem, num = m_idx;
if (num)
{
rem = BLOCKSIZE - num;
if (length >= rem)
{
// Process
memcpy_s(m_acc + num, BLOCKSIZE - num, input, rem);
Poly1305_HashBlocks(m_h, m_r, m_acc, BLOCKSIZE, 1);
input += rem; length -= rem;
}
else
{
// Accumulate
memcpy_s(m_acc + num, BLOCKSIZE - num, input, length);
m_idx = num + length;
return;
}
}
rem = length % BLOCKSIZE;
length -= rem;
if (length >= BLOCKSIZE) {
Poly1305_HashBlocks(m_h, m_r, input, length, 1);
input += length;
}
if (rem)
std::memcpy(m_acc, input, rem);
m_idx = rem;
}
void Poly1305TLS_Base::TruncatedFinal(byte *mac, size_t size)
{
CRYPTOPP_ASSERT(mac); // Pointer is valid
ThrowIfInvalidTruncatedSize(size);
size_t num = m_idx;
if (num)
{
m_acc[num++] = 1; /* pad bit */
while (num < BLOCKSIZE)
m_acc[num++] = 0;
Poly1305_HashBlocks(m_h, m_r, m_acc, BLOCKSIZE, 0);
}
Poly1305_HashFinal(m_h, m_n, mac, size);
Restart();
}
void Poly1305TLS_Base::Restart()
{
m_h[0] = m_h[1] = m_h[2] = m_h[3] = m_h[4] = 0;
m_idx = 0;
}
template class Poly1305_Base<AES>;
template class Poly1305<AES>;
NAMESPACE_END
aes.h
Class file for the AES cipher (Rijndael)
ConstByteArrayParameter
Used to pass byte array input as part of a NameValuePairs object.
Definition algparam.h:25
ConstByteArrayParameter::begin
const byte * begin() const
Pointer to the first byte in the memory block.
Definition algparam.h:84
ConstByteArrayParameter::size
size_t size() const
Length of the memory block.
Definition algparam.h:88
FixedSizeAlignedSecBlock
Fixed size stack-based SecBlock with 16-byte alignment.
Definition secblock.h:1259
NameValuePairs
Interface for retrieving values given their names.
Definition cryptlib.h:327
NameValuePairs::GetValue
bool GetValue(const char *name, T &value) const
Get a named value.
Definition cryptlib.h:384
Poly1305_Base
Poly1305 message authentication code base class.
Definition poly1305.h:44
Poly1305_Base::Update
void Update(const byte *input, size_t length)
Updates a hash with additional input.
Definition poly1305.cpp:219
Poly1305_Base::TruncatedFinal
void TruncatedFinal(byte *mac, size_t size)
Computes the hash of the current message.
Definition poly1305.cpp:259
Poly1305_Base::GetNextIV
void GetNextIV(RandomNumberGenerator &rng, byte *iv)
Retrieves a secure IV for the next message.
Definition poly1305.cpp:301
Poly1305_Base::UncheckedSetKey
void UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &params)
Sets the key for this object without performing parameter validation.
Definition poly1305.cpp:190
Poly1305_Base::Restart
void Restart()
Restart the hash.
Definition poly1305.cpp:307
Poly1305_Base::Resynchronize
void Resynchronize(const byte *iv, int ivLength=-1)
Resynchronize with an IV.
Definition poly1305.cpp:283
Poly1305_Base::AlgorithmProvider
std::string AlgorithmProvider() const
Retrieve the provider of this algorithm.
Definition poly1305.cpp:184
Poly1305
Poly1305 message authentication code.
Definition poly1305.h:137
Poly1305TLS_Base::UncheckedSetKey
void UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &params)
Sets the key for this object without performing parameter validation.
Definition poly1305.cpp:315
Poly1305TLS_Base::TruncatedFinal
void TruncatedFinal(byte *mac, size_t size)
Computes the hash of the current message.
Definition poly1305.cpp:374
Poly1305TLS_Base::Update
void Update(const byte *input, size_t length)
Updates a hash with additional input.
Definition poly1305.cpp:335
Poly1305TLS_Base::Restart
void Restart()
Restart the hash.
Definition poly1305.cpp:394
RandomNumberGenerator
Interface for random number generators.
Definition cryptlib.h:1440
RandomNumberGenerator::GenerateBlock
virtual void GenerateBlock(byte *output, size_t size)
Generate random array of bytes.
word32
unsigned int word32
32-bit unsigned datatype
Definition config_int.h:72
word64
unsigned long long word64
64-bit unsigned datatype
Definition config_int.h:101
cpu.h
Functions for CPU features and intrinsics.
cryptlib.h
Abstract base classes that provide a uniform interface to this library.
LITTLE_ENDIAN_ORDER
@ LITTLE_ENDIAN_ORDER
byte order is little-endian
Definition cryptlib.h:150
SaturatingSubtract
T1 SaturatingSubtract(const T1 &a, const T2 &b)
Performs a saturating subtract clamped at 0.
Definition misc.h:1302
memcpy_s
void memcpy_s(void *dest, size_t sizeInBytes, const void *src, size_t count)
Bounds checking replacement for memcpy()
Definition misc.h:527
CryptoPP
Crypto++ library namespace.
Name::IV
const char * IV()
ConstByteArrayParameter, also accepts const byte * for backwards compatibility.
Definition argnames.h:21
pch.h
Precompiled header file.
poly1305.h
Classes for Poly1305 message authentication code.
CRYPTOPP_ASSERT
#define CRYPTOPP_ASSERT(exp)
Debugging and diagnostic assertion.
Definition trap.h:68