des.cpp
// des.cpp - modified by Wei Dai from Phil Karn's des.c
// The original code and all modifications are in the public domain.
/*
* This is a major rewrite of my old public domain DES code written
* circa 1987, which in turn borrowed heavily from Jim Gillogly's 1977
* public domain code. I pretty much kept my key scheduling code, but
* the actual encrypt/decrypt routines are taken from from Richard
* Outerbridge's DES code as printed in Schneier's "Applied Cryptography."
*
* This code is in the public domain. I would appreciate bug reports and
* enhancements.
*
* Phil Karn KA9Q, karn@unix.ka9q.ampr.org, August 1994.
*/
#include "pch.h"
#include "misc.h"
#include "des.h"
NAMESPACE_BEGIN(CryptoPP)
typedef BlockGetAndPut<word32, BigEndian> Block;
// Richard Outerbridge's initial permutation algorithm
/*
inline void IPERM(word32 &left, word32 &right)
{
word32 work;
work = ((left >> 4) ^ right) & 0x0f0f0f0f;
right ^= work;
left ^= work << 4;
work = ((left >> 16) ^ right) & 0xffff;
right ^= work;
left ^= work << 16;
work = ((right >> 2) ^ left) & 0x33333333;
left ^= work;
right ^= (work << 2);
work = ((right >> 8) ^ left) & 0xff00ff;
left ^= work;
right ^= (work << 8);
right = rotl(right, 1);
work = (left ^ right) & 0xaaaaaaaa;
left ^= work;
right ^= work;
left = rotl(left, 1);
}
inline void FPERM(word32 &left, word32 &right)
{
word32 work;
right = rotr(right, 1);
work = (left ^ right) & 0xaaaaaaaa;
left ^= work;
right ^= work;
left = rotr(left, 1);
work = ((left >> 8) ^ right) & 0xff00ff;
right ^= work;
left ^= work << 8;
work = ((left >> 2) ^ right) & 0x33333333;
right ^= work;
left ^= work << 2;
work = ((right >> 16) ^ left) & 0xffff;
left ^= work;
right ^= work << 16;
work = ((right >> 4) ^ left) & 0x0f0f0f0f;
left ^= work;
right ^= work << 4;
}
*/
// Wei Dai's modification to Richard Outerbridge's initial permutation
// algorithm, this one is faster if you have access to rotate instructions
// (like in MSVC)
static inline void IPERM(word32 &left, word32 &right)
{
word32 work;
right = rotlConstant<4>(right);
work = (left ^ right) & 0xf0f0f0f0;
left ^= work;
right = rotrConstant<20>(right^work);
work = (left ^ right) & 0xffff0000;
left ^= work;
right = rotrConstant<18>(right^work);
work = (left ^ right) & 0x33333333;
left ^= work;
right = rotrConstant<6>(right^work);
work = (left ^ right) & 0x00ff00ff;
left ^= work;
right = rotlConstant<9>(right^work);
work = (left ^ right) & 0xaaaaaaaa;
left = rotlConstant<1>(left^work);
right ^= work;
}
static inline void FPERM(word32 &left, word32 &right)
{
word32 work;
right = rotrConstant<1>(right);
work = (left ^ right) & 0xaaaaaaaa;
right ^= work;
left = rotrConstant<9>(left^work);
work = (left ^ right) & 0x00ff00ff;
right ^= work;
left = rotlConstant<6>(left^work);
work = (left ^ right) & 0x33333333;
right ^= work;
left = rotlConstant<18>(left^work);
work = (left ^ right) & 0xffff0000;
right ^= work;
left = rotlConstant<20>(left^work);
work = (left ^ right) & 0xf0f0f0f0;
right ^= work;
left = rotrConstant<4>(left^work);
}
void DES::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)
{
AssertValidKeyLength(length);
RawSetKey(GetCipherDirection(), userKey);
}
#ifndef CRYPTOPP_IMPORTS
/* Tables defined in the Data Encryption Standard documents
* Three of these tables, the initial permutation, the final
* permutation and the expansion operator, are regular enough that
* for speed, we hard-code them. They're here for reference only.
* Also, the S and P boxes are used by a separate program, gensp.c,
* to build the combined SP box, Spbox[]. They're also here just
* for reference.
*/
#ifdef notdef
/* initial permutation IP */
static byte ip[] = {
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6,
64, 56, 48, 40, 32, 24, 16, 8,
57, 49, 41, 33, 25, 17, 9, 1,
59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7
};
/* final permutation IP^-1 */
static byte fp[] = {
40, 8, 48, 16, 56, 24, 64, 32,
39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30,
37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28,
35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26,
33, 1, 41, 9, 49, 17, 57, 25
};
/* expansion operation matrix */
static byte ei[] = {
32, 1, 2, 3, 4, 5,
4, 5, 6, 7, 8, 9,
8, 9, 10, 11, 12, 13,
12, 13, 14, 15, 16, 17,
16, 17, 18, 19, 20, 21,
20, 21, 22, 23, 24, 25,
24, 25, 26, 27, 28, 29,
28, 29, 30, 31, 32, 1
};
/* The (in)famous S-boxes */
static byte sbox[8][64] = {
/* S1 */
14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13,
/* S2 */
15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9,
/* S3 */
10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12,
/* S4 */
7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14,
/* S5 */
2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3,
/* S6 */
12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13,
/* S7 */
4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12,
/* S8 */
13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11
};
/* 32-bit permutation function P used on the output of the S-boxes */
namespace {
const byte p32i[] = {
16, 7, 20, 21,
29, 12, 28, 17,
1, 15, 23, 26,
5, 18, 31, 10,
2, 8, 24, 14,
32, 27, 3, 9,
19, 13, 30, 6,
22, 11, 4, 25
};
}
#endif
/* permuted choice table (key) */
namespace {
const byte pc1[] = {
57, 49, 41, 33, 25, 17, 9,
1, 58, 50, 42, 34, 26, 18,
10, 2, 59, 51, 43, 35, 27,
19, 11, 3, 60, 52, 44, 36,
63, 55, 47, 39, 31, 23, 15,
7, 62, 54, 46, 38, 30, 22,
14, 6, 61, 53, 45, 37, 29,
21, 13, 5, 28, 20, 12, 4
};
}
/* number left rotations of pc1 */
namespace {
const byte totrot[] = {
1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28
};
}
/* permuted choice key (table) */
namespace {
const byte pc2[] = {
14, 17, 11, 24, 1, 5,
3, 28, 15, 6, 21, 10,
23, 19, 12, 4, 26, 8,
16, 7, 27, 20, 13, 2,
41, 52, 31, 37, 47, 55,
30, 40, 51, 45, 33, 48,
44, 49, 39, 56, 34, 53,
46, 42, 50, 36, 29, 32
};
}
/* End of DES-defined tables */
/* bit 0 is left-most in byte */
namespace {
const int bytebit[] = {
0200,0100,040,020,010,04,02,01
};
}
/* Set key (initialize key schedule array) */
void RawDES::RawSetKey(CipherDir dir, const byte *key)
{
#if (CRYPTOPP_MSC_VERSION >= 1600) || (__cplusplus >= 201103L)
# define REGISTER /* Define to nothing for C++11 and above */
#else
# define REGISTER register
#endif
SecByteBlock buffer(56+56+8);
byte *const pc1m=buffer; /* place to modify pc1 into */
byte *const pcr=pc1m+56; /* place to rotate pc1 into */
byte *const ks=pcr+56;
REGISTER int i,j,l;
int m;
for (j=0; j<56; j++) { /* convert pc1 to bits of key */
l=pc1[j]-1; /* integer bit location */
m = l & 07; /* find bit */
pc1m[j]=(key[l>>3] & /* find which key byte l is in */
bytebit[m]) /* and which bit of that byte */
? 1 : 0; /* and store 1-bit result */
}
for (i=0; i<16; i++) { /* key chunk for each iteration */
std::memset(ks,0,8); /* Clear key schedule */
for (j=0; j<56; j++) /* rotate pc1 the right amount */
pcr[j] = pc1m[(l=j+totrot[i])<(j<28? 28 : 56) ? l: l-28];
/* rotate left and right halves independently */
for (j=0; j<48; j++){ /* select bits individually */
/* check bit that goes to ks[j] */
if (pcr[pc2[j]-1]){
/* mask it in if it's there */
l= j % 6;
ks[j/6] |= bytebit[l] >> 2;
}
}
/* Now convert to odd/even interleaved form for use in F */
k[2*i] = ((word32)ks[0] << 24)
| ((word32)ks[2] << 16)
| ((word32)ks[4] << 8)
| ((word32)ks[6]);
k[2*i+1] = ((word32)ks[1] << 24)
| ((word32)ks[3] << 16)
| ((word32)ks[5] << 8)
| ((word32)ks[7]);
}
if (dir==DECRYPTION) // reverse key schedule order
for (i=0; i<16; i+=2)
{
std::swap(k[i], k[32-2-i]);
std::swap(k[i+1], k[32-1-i]);
}
}
void RawDES::RawProcessBlock(word32 &l_, word32 &r_) const
{
word32 l = l_, r = r_;
const word32 *kptr=k;
for (unsigned i=0; i<8; i++)
{
word32 work = rotrConstant<4>(r) ^ kptr[4 * i + 0];
l ^= Spbox[6][(work) & 0x3f]
^ Spbox[4][(work >> 8) & 0x3f]
^ Spbox[2][(work >> 16) & 0x3f]
^ Spbox[0][(work >> 24) & 0x3f];
work = r ^ kptr[4*i+1];
l ^= Spbox[7][(work) & 0x3f]
^ Spbox[5][(work >> 8) & 0x3f]
^ Spbox[3][(work >> 16) & 0x3f]
^ Spbox[1][(work >> 24) & 0x3f];
work = rotrConstant<4>(l) ^ kptr[4 * i + 2];
r ^= Spbox[6][(work) & 0x3f]
^ Spbox[4][(work >> 8) & 0x3f]
^ Spbox[2][(work >> 16) & 0x3f]
^ Spbox[0][(work >> 24) & 0x3f];
work = l ^ kptr[4*i+3];
r ^= Spbox[7][(work) & 0x3f]
^ Spbox[5][(work >> 8) & 0x3f]
^ Spbox[3][(work >> 16) & 0x3f]
^ Spbox[1][(work >> 24) & 0x3f];
}
l_ = l; r_ = r;
}
void DES_EDE2::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)
{
AssertValidKeyLength(length);
m_des1.RawSetKey(GetCipherDirection(), userKey);
m_des2.RawSetKey(ReverseCipherDir(GetCipherDirection()), userKey+8);
}
void DES_EDE2::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
word32 l,r;
Block::Get(inBlock)(l)(r);
IPERM(l,r);
m_des1.RawProcessBlock(l, r);
m_des2.RawProcessBlock(r, l);
m_des1.RawProcessBlock(l, r);
FPERM(l,r);
Block::Put(xorBlock, outBlock)(r)(l);
}
void DES_EDE3::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)
{
AssertValidKeyLength(length);
m_des1.RawSetKey(GetCipherDirection(), userKey + (IsForwardTransformation() ? 0 : 16));
m_des2.RawSetKey(ReverseCipherDir(GetCipherDirection()), userKey + 8);
m_des3.RawSetKey(GetCipherDirection(), userKey + (IsForwardTransformation() ? 16 : 0));
}
void DES_EDE3::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
word32 l,r;
Block::Get(inBlock)(l)(r);
IPERM(l,r);
m_des1.RawProcessBlock(l, r);
m_des2.RawProcessBlock(r, l);
m_des3.RawProcessBlock(l, r);
FPERM(l,r);
Block::Put(xorBlock, outBlock)(r)(l);
}
#endif // #ifndef CRYPTOPP_IMPORTS
static inline bool CheckParity(byte b)
{
unsigned int a = b ^ (b >> 4);
return ((a ^ (a>>1) ^ (a>>2) ^ (a>>3)) & 1) == 1;
}
bool DES::CheckKeyParityBits(const byte *key)
{
for (unsigned int i=0; i<8; i++)
if (!CheckParity(key[i]))
return false;
return true;
}
void DES::CorrectKeyParityBits(byte *key)
{
for (unsigned int i=0; i<8; i++)
if (!CheckParity(key[i]))
key[i] ^= 1;
}
// Encrypt or decrypt a block of data in ECB mode
void DES::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
word32 l,r;
Block::Get(inBlock)(l)(r);
IPERM(l,r);
RawProcessBlock(l, r);
FPERM(l,r);
Block::Put(xorBlock, outBlock)(r)(l);
}
void DES_XEX3::Base::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &)
{
AssertValidKeyLength(length);
if (!m_des.get())
m_des.reset(new DES::Encryption);
std::memcpy(m_x1, key + (IsForwardTransformation() ? 0 : 16), BLOCKSIZE);
m_des->RawSetKey(GetCipherDirection(), key + 8);
std::memcpy(m_x3, key + (IsForwardTransformation() ? 16 : 0), BLOCKSIZE);
}
void DES_XEX3::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
xorbuf(outBlock, inBlock, m_x1, BLOCKSIZE);
m_des->ProcessAndXorBlock(outBlock, xorBlock, outBlock);
xorbuf(outBlock, m_x3, BLOCKSIZE);
}
NAMESPACE_END
DES::CheckKeyParityBits
static bool CheckKeyParityBits(const byte *key)
check DES key parity bits
Definition des.cpp:420
DES::CorrectKeyParityBits
static void CorrectKeyParityBits(byte *key)
correct DES key parity bits
Definition des.cpp:428
FixedBlockSize< 8 >::BLOCKSIZE
static const int BLOCKSIZE
Definition seckey.h:44
NameValuePairs
Interface for retrieving values given their names.
Definition cryptlib.h:327
word32
unsigned int word32
32-bit unsigned datatype
Definition config_int.h:72
CipherDir
CipherDir
Specifies a direction for a cipher to operate.
Definition cryptlib.h:128
DECRYPTION
@ DECRYPTION
the cipher is performing decryption
Definition cryptlib.h:132
des.h
Classes for DES, 2-key Triple-DES, 3-key Triple-DES and DESX.
misc.h
Utility functions for the Crypto++ library.
rotlConstant
T rotlConstant(T x)
Performs a left rotate.
Definition misc.h:1757
rotrConstant
T rotrConstant(T x)
Performs a right rotate.
Definition misc.h:1783
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.
ReverseCipherDir
CipherDir ReverseCipherDir(CipherDir dir)
Inverts the cipher's direction.
Definition seckey.h:32
BlockCipherDocumentation::Encryption
BlockCipher Encryption
implements the BlockCipher interface
Definition seckey.h:401
BlockGetAndPut
Access a block of memory.
Definition misc.h:3053