Crypto++ 8.9 Free C++ class library of cryptographic schemes

keccak.cpp
1 // keccak.cpp - modified by Wei Dai from Ronny Van Keer's public domain
2 // sha3-simple.c. All modifications here are placed in the
3 // public domain by Wei Dai.
4 // Keccack core function moved to keccakc.cpp in AUG 2018
5 // by Jeffrey Walton. Separating the core file allows both
6 // SHA3 and Keccack to share the core implementation.
7
8 /*
9 The Keccak sponge function, designed by Guido Bertoni, Joan Daemen,
10 Michael Peeters and Gilles Van Assche. For more information, feedback or
11 questions, please refer to our website: http://keccak.noekeon.org/
12
13 Implementation by Ronny Van Keer, hereby denoted as "the implementer".
14
15 To the extent possible under law, the implementer has waived all copyright
16 and related or neighboring rights to the source code in this file.
17 http://creativecommons.org/publicdomain/zero/1.0/
18 */
19
20 #include "pch.h"
21 #include "keccak.h"
22
23 NAMESPACE_BEGIN(CryptoPP)
24
25 // The Keccak core function
26 extern void KeccakF1600(word64 *state);
27
28 void Keccak::Update(const byte *input, size_t length)
29 {
30 CRYPTOPP_ASSERT(!(input == NULLPTR && length != 0));
31 if (length == 0) { return; }
32
33 size_t spaceLeft;
34 while (length >= (spaceLeft = r() - m_counter))
35 {
36 if (spaceLeft)
37 xorbuf(m_state.BytePtr() + m_counter, input, spaceLeft);
38 KeccakF1600(m_state);
39 input += spaceLeft;
40 length -= spaceLeft;
41 m_counter = 0;
42 }
43
44 if (length)
45 xorbuf(m_state.BytePtr() + m_counter, input, length);
46 m_counter += (unsigned int)length;
47 }
48
49 void Keccak::Restart()
50 {
51 std::memset(m_state, 0, m_state.SizeInBytes());
52 m_counter = 0;
53 }
54
55 void Keccak::TruncatedFinal(byte *hash, size_t size)
56 {
57 CRYPTOPP_ASSERT(hash != NULLPTR);
58 ThrowIfInvalidTruncatedSize(size);
59
60 m_state.BytePtr()[m_counter] ^= 0x01;
61 m_state.BytePtr()[r()-1] ^= 0x80;
62 KeccakF1600(m_state);
63 std::memcpy(hash, m_state, size);
64 Restart();
65 }
66
67 NAMESPACE_END
Keccak::TruncatedFinal
void TruncatedFinal(byte *hash, size_t size)
Computes the hash of the current message.
Definition: keccak.cpp:55
Keccak::Restart
void Restart()
Restart the hash.
Definition: keccak.cpp:49
Keccak::Update
void Update(const byte *input, size_t length)
Updates a hash with additional input.
Definition: keccak.cpp:28
SecBlock::BytePtr
byte * BytePtr()
Provides a byte pointer to the first element in the memory block.
Definition: secblock.h:876
SecBlock::SizeInBytes
size_type SizeInBytes() const
Provides the number of bytes in the SecBlock.
Definition: secblock.h:885
word64
unsigned long long word64
64-bit unsigned datatype
Definition: config_int.h:101
keccak.h
Classes for Keccak message digests.
xorbuf
CRYPTOPP_DLL void xorbuf(byte *buf, const byte *mask, size_t count)
Performs an XOR of a buffer with a mask.
CryptoPP
Crypto++ library namespace.
pch.h
Precompiled header file.
CRYPTOPP_ASSERT
#define CRYPTOPP_ASSERT(exp)
Debugging and diagnostic assertion.
Definition: trap.h:68