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libcruft-util/hash/md4.cpp

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/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2013 Danny Robson <danny@nerdcruft.net>
*/
#include "md4.hpp"
#include "../bitwise.hpp"
#include "../debug.hpp"
#include "../endian.hpp"
#include "../types.hpp"
#include <cstring>
using util::hash::MD4;
///////////////////////////////////////////////////////////////////////////////
// Auxiliary functions for each set of rounds
static constexpr
uint32_t
F (uint32_t X, uint32_t Y, uint32_t Z)
{
return (X & Y) | (~X & Z);
}
//-----------------------------------------------------------------------------
static constexpr
uint32_t
G (uint32_t X, uint32_t Y, uint32_t Z)
{
return (X & Y) | (X & Z) | (Y & Z);
}
//-----------------------------------------------------------------------------
static constexpr
uint32_t
H (uint32_t X, uint32_t Y, uint32_t Z)
{
return X ^ Y ^ Z;
}
//-----------------------------------------------------------------------------
static constexpr uint32_t DEFAULT_A = 0x67452301;
static constexpr uint32_t DEFAULT_B = 0xefcdab89;
static constexpr uint32_t DEFAULT_C = 0x98badcfe;
static constexpr uint32_t DEFAULT_D = 0x10325476;
///////////////////////////////////////////////////////////////////////////////
MD4::MD4 ()
{
reset ();
static_assert (sizeof (MD4::X) == sizeof (MD4::Xb),
"Byte and word buffer size must match exactly");
static_assert (sizeof (MD4::ABCD) == sizeof (MD4::digest_t),
"Internal state must match the size of the digest");
}
//-----------------------------------------------------------------------------
void
MD4::reset (void)
{
m_total = 0;
ABCD[0] = DEFAULT_A;
ABCD[1] = DEFAULT_B;
ABCD[2] = DEFAULT_C;
ABCD[3] = DEFAULT_D;
memset (Xb, 0, sizeof (Xb));
}
///////////////////////////////////////////////////////////////////////////////
void
MD4::update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept
{
CHECK_LE (first, last);
update (first, last - first);
}
//-----------------------------------------------------------------------------
void
MD4::update (const void *restrict _data, size_t size) noexcept
{
CHECK (_data);
auto data = static_cast<const uint8_t *restrict> (_data);
size_t offset = m_total % sizeof (Xb);
size_t remain = sizeof (Xb) - offset;
if (size > remain) {
memcpy (Xb + offset, data, remain);
transform ();
m_total += remain;
size -= remain;
data += remain;
while (size >= sizeof (Xb)) {
memcpy (Xb, data, sizeof (Xb));
transform ();
m_total += sizeof (Xb);
size -= sizeof (Xb);
data += sizeof (Xb);
}
offset = 0;
}
memcpy (Xb + offset, data, size);
m_total += size;
}
///////////////////////////////////////////////////////////////////////////////
MD4::digest_t
MD4::digest (void) const
{
digest_t d;
memcpy (d.data (), ABCD.data(), sizeof (ABCD));
return d;
}
///////////////////////////////////////////////////////////////////////////////
void
MD4::transform (void)
{
uint32_t A = ABCD[0],
B = ABCD[1],
C = ABCD[2],
D = ABCD[3];
#define ROUND1(a,b,c,d,k,s) do { \
(a) += F((b), (c), (d)) + X[k]; \
(a) = rotatel ((a), (s)); \
} while (0)
ROUND1(A,B,C,D, 0, 3);
ROUND1(D,A,B,C, 1, 7);
ROUND1(C,D,A,B, 2, 11);
ROUND1(B,C,D,A, 3, 19);
ROUND1(A,B,C,D, 4, 3);
ROUND1(D,A,B,C, 5, 7);
ROUND1(C,D,A,B, 6, 11);
ROUND1(B,C,D,A, 7, 19);
ROUND1(A,B,C,D, 8, 3);
ROUND1(D,A,B,C, 9, 7);
ROUND1(C,D,A,B, 10, 11);
ROUND1(B,C,D,A, 11, 19);
ROUND1(A,B,C,D, 12, 3);
ROUND1(D,A,B,C, 13, 7);
ROUND1(C,D,A,B, 14, 11);
ROUND1(B,C,D,A, 15, 19);
#define ROUND2(a,b,c,d,k,s) do { \
(a) += G((b),(c),(d)) + X[k] + 0x5A827999u; \
(a) = rotatel ((a), (s)); \
} while (0)
ROUND2(A,B,C,D, 0, 3);
ROUND2(D,A,B,C, 4, 5);
ROUND2(C,D,A,B, 8, 9);
ROUND2(B,C,D,A, 12, 13);
ROUND2(A,B,C,D, 1, 3);
ROUND2(D,A,B,C, 5, 5);
ROUND2(C,D,A,B, 9, 9);
ROUND2(B,C,D,A, 13, 13);
ROUND2(A,B,C,D, 2, 3);
ROUND2(D,A,B,C, 6, 5);
ROUND2(C,D,A,B, 10, 9);
ROUND2(B,C,D,A, 14, 13);
ROUND2(A,B,C,D, 3, 3);
ROUND2(D,A,B,C, 7, 5);
ROUND2(C,D,A,B, 11, 9);
ROUND2(B,C,D,A, 15, 13);
#define ROUND3(a,b,c,d,k,s) do { \
(a) += H((b),(c),(d)) + X[k] + 0x6ED9EBA1u; \
(a) = rotatel ((a), (s)); \
} while (0)
ROUND3(A,B,C,D, 0, 3);
ROUND3(D,A,B,C, 8, 9);
ROUND3(C,D,A,B, 4, 11);
ROUND3(B,C,D,A, 12, 15);
ROUND3(A,B,C,D, 2, 3);
ROUND3(D,A,B,C, 10, 9);
ROUND3(C,D,A,B, 6, 11);
ROUND3(B,C,D,A, 14, 15);
ROUND3(A,B,C,D, 1, 3);
ROUND3(D,A,B,C, 9, 9);
ROUND3(C,D,A,B, 5, 11);
ROUND3(B,C,D,A, 13, 15);
ROUND3(A,B,C,D, 3, 3);
ROUND3(D,A,B,C, 11, 9);
ROUND3(C,D,A,B, 7, 11);
ROUND3(B,C,D,A, 15, 15);
ABCD[0] += A;
ABCD[1] += B;
ABCD[2] += C;
ABCD[3] += D;
}
///////////////////////////////////////////////////////////////////////////////
void
MD4::finish (void)
{
uint64_t bits = m_total * 8;
{
// Pad with the mandatory 1 bit
size_t offset = m_total % sizeof (Xb);
Xb[offset] = 0x80;
}
{
// Pad the remainder with 0's, until 56 bytes
size_t offset = (m_total + 1) % sizeof (Xb);
size_t remain = (56 - offset % sizeof (Xb)) % sizeof (Xb);
if (offset > 56) {
memset (Xb + offset, 0, sizeof (Xb) - offset);
transform ();
remain -= sizeof (Xb) - offset;
offset = 0;
}
memset (Xb + offset, 0, remain);
// Put in the length (in bits) least significant first
for (size_t i = 0; i < sizeof (bits); ++i) {
Xb[56 + i] = bits & 0xFF;
bits >>= 8;
}
transform ();
}
}
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