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{{draft task|Data_Encryption_Standard}} Demonstrate the [[wp:Data_Encryption_Standard|Data Encryption Standard]]. For a complete description of the algorithm see: [http://page.math.tu-berlin.de/~kant/teaching/hess/krypto-ws2006/des.htm The DES Algorithm Illustrated]

Use the :Key 0e329232ea6d0d73 :to encrypt 8787878787878787 :and display the result 0000000000000000.

Bonus (optional): add standard padding to match the C#, Java, Modula-2, Kotlin, and Phix entries, so the above encrypted result would instead be 0000000000000000A913F4CB0BD30F97.

## C

{{trans|D}}

```#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef unsigned char ubyte;

#define KEY_LEN 8
typedef ubyte key_t[KEY_LEN];

const static ubyte 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
};

const static ubyte 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
};

const static ubyte 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
};

const static ubyte E[] = {
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
};

const static ubyte S[][64] = {
{
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
},
{
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
},
{
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
},
{
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
},
{
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
},
{
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
},
{
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
},
{
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
}
};

const static ubyte P[] = {
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
};

const static ubyte IP2[] = {
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
};

const static ubyte SHIFTS[] = {
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
};

typedef struct {
ubyte *data;
int len;
} String;

/*
* Transform a single nibble into a hex character
*
* in: a value < 0x10
*
* returns: the character that represents the nibble
*/
static char toHex(ubyte in) {
if (0x00 <= in && in < 0x0A) {
return '0' + in;
}
if (0x0A <= in && in <= 0x0F) {
return 'A' + in - 0x0A;
}
return 0;
}

/*
* Convert an array of bytes into a string
*
* ptr: the array of bytes
* len: the number of bytes
* out: a buffer allocated by the caller with enough space for 2*len+1 characters
*/
static void printBytes(const ubyte *ptr, int len, char *out) {
while (len-- > 0) {
*out++ = toHex(*ptr >> 4);
*out++ = toHex(*ptr & 0x0F);

ptr++;
}
*out = 0;
}

/*
* Gets the value of a bit in an array of bytes
*
* src: the array of bytes to index
* index: the desired bit to test the value of
*
* returns: the bit at the specified position in the array
*/
static int peekBit(const ubyte *src, int index) {
int cell = index / 8;
int bit = 7 - index % 8;
return (src[cell] & (1 << bit)) != 0;
}

/*
* Sets the value of a bit in an array of bytes
*
* dst: the array of bits to set a bit in
* index: the position of the bit to set
* value: the value for the bit to set
*/
static void pokeBit(ubyte *dst, int index, int value) {
int cell = index / 8;
int bit = 7 - index % 8;
if (value == 0) {
dst[cell] &= ~(1 << bit);
} else {
dst[cell] |= (1 << bit);
}
}

/*
* Transforms one array of bytes by shifting the bits the specified number of positions
*
* src: the array to shift bits from
* len: the length of the src array
* times: the number of positions that the bits should be shifted
* dst: a bytes array allocated by the caller to store the shifted values
*/
static void shiftLeft(const ubyte *src, int len, int times, ubyte *dst) {
int i, t;
for (i = 0; i <= len; ++i) {
pokeBit(dst, i, peekBit(src, i));
}
for (t = 1; t <= times; ++t) {
int temp = peekBit(dst, 0);
for (i = 1; i <= len; ++i) {
pokeBit(dst, i - 1, peekBit(dst, i));
}
pokeBit(dst, len - 1, temp);
}
}

/*
* Calculates the sub keys to be used in processing the messages
*
* key: the array of bytes representing the key
* ks: the subkeys that have been allocated by the caller
*/
typedef ubyte subkey_t[17][6]; /* 17 sets of 48 bits */
static void getSubKeys(const key_t key, subkey_t ks) {
ubyte c[17][7];  /* 56 bits */
ubyte d[17][4];  /* 28 bits */
ubyte kp[7];
int i, j;

/* intialize */
memset(c, 0, sizeof(c));
memset(d, 0, sizeof(d));
memset(ks, 0, sizeof(subkey_t));

/* permute 'key' using table PC1 */
for (i = 0; i < 56; ++i) {
pokeBit(kp, i, peekBit(key, PC1[i] - 1));
}

/* split 'kp' in half and process the resulting series of 'c' and 'd' */
for (i = 0; i < 28; ++i) {
pokeBit(c[0], i, peekBit(kp, i));
pokeBit(d[0], i, peekBit(kp, i + 28));
}

/* shift the components of c and d */
for (i = 1; i < 17; ++i) {
shiftLeft(c[i - 1], 28, SHIFTS[i - 1], c[i]);
shiftLeft(d[i - 1], 28, SHIFTS[i - 1], d[i]);
}

/* merge 'd' into 'c' */
for (i = 1; i < 17; ++i) {
for (j = 28; j < 56; ++j) {
pokeBit(c[i], j, peekBit(d[i], j - 28));
}
}

/* form the sub-keys and store them in 'ks'
* permute 'c' using table PC2 */
for (i = 1; i < 17; ++i) {
for (j = 0; j < 48; ++j) {
pokeBit(ks[i], j, peekBit(c[i], PC2[j] - 1));
}
}
}

/*
* Function used in processing the messages
*
* r: an array of bytes to be processed
* ks: one of the subkeys to be used for processing
* sp: output from the processing
*/
static void f(ubyte *r, ubyte *ks, ubyte *sp) {
ubyte er[6]; /* 48 bits */
ubyte sr[4]; /* 32 bits */
int i;

/* initialize */
memset(er, 0, sizeof(er));
memset(sr, 0, sizeof(sr));

/* permute 'r' using table E */
for (i = 0; i < 48; ++i) {
pokeBit(er, i, peekBit(r, E[i] - 1));
}

/* xor 'er' with 'ks' and store back into 'er' */
for (i = 0; i < 6; ++i) {
er[i] ^= ks[i];
}

/* process 'er' six bits at a time and store resulting four bits in 'sr' */
for (i = 0; i < 8; ++i) {
int j = i * 6;
int b[6];
int k, row, col, m, n;

for (k = 0; k < 6; ++k) {
b[k] = peekBit(er, j + k) != 0 ? 1 : 0;
}

row = 2 * b[0] + b[5];
col = 8 * b[1] + 4 * b[2] + 2 * b[3] + b[4];
m = S[i][row * 16 + col]; /* apply table s */
n = 1;

while (m > 0) {
int p = m % 2;
pokeBit(sr, (i + 1) * 4 - n, p == 1);
m /= 2;
n++;
}
}

/* permute sr using table P */
for (i = 0; i < 32; ++i) {
pokeBit(sp, i, peekBit(sr, P[i] - 1));
}
}

/*
* Processing of block of the message
*
* message: an 8 byte block from the message
* ks: the subkeys to use in processing
* ep: space for an encoded 8 byte block allocated by the caller
*/
static void processMessage(const ubyte *message, subkey_t ks, ubyte *ep) {
ubyte left[17][4];  /* 32 bits */
ubyte right[17][4]; /* 32 bits */
ubyte mp[8];        /* 64 bits */
ubyte e[8];         /* 64 bits */
int i, j;

/* permute 'message' using table IP */
for (i = 0; i < 64; ++i) {
pokeBit(mp, i, peekBit(message, IP[i] - 1));
}

/* split 'mp' in half and process the resulting series of 'l' and 'r */
for (i = 0; i < 32; ++i) {
pokeBit(left[0], i, peekBit(mp, i));
pokeBit(right[0], i, peekBit(mp, i + 32));
}
for (i = 1; i < 17; ++i) {
ubyte fs[4]; /* 32 bits */

memcpy(left[i], right[i - 1], 4);
f(right[i - 1], ks[i], fs);
for (j = 0; j < 4; ++j) {
left[i - 1][j] ^= fs[j];
}
memcpy(right[i], left[i - 1], 4);
}

/* amalgamate r[16] and l[16] (in that order) into 'e' */
for (i = 0; i < 32; ++i) {
pokeBit(e, i, peekBit(right[16], i));
}
for (i = 32; i < 64; ++i) {
pokeBit(e, i, peekBit(left[16], i - 32));
}

/* permute 'e' using table IP2 ad return result as a hex string */
for (i = 0; i < 64; ++i) {
pokeBit(ep, i, peekBit(e, IP2[i] - 1));
}
}

/*
* Encrypts a message using DES
*
* key: the key to use to encrypt the message
* message: the message to be encrypted
* len: the length of the message
*
* returns: a paring of dynamically allocated memory for the encoded message,
*          and the length of the encoded message.
*          the caller will need to free the memory after use.
*/
String encrypt(const key_t key, const ubyte *message, int len) {
String result = { 0, 0 };
subkey_t ks;
int i;

getSubKeys(key, ks);

padByte = 8 - len % 8;
result.data = (ubyte*)malloc(result.len);
memcpy(result.data, message, len);

for (i = 0; i < result.len; i += 8) {
processMessage(&result.data[i], ks, &result.data[i]);
}

return result;
}

/*
* Decrypts a message using DES
*
* key: the key to use to decrypt the message
* message: the message to be decrypted
* len: the length of the message
*
* returns: a paring of dynamically allocated memory for the decoded message,
*          and the length of the decoded message.
*          the caller will need to free the memory after use.
*/
String decrypt(const key_t key, const ubyte *message, int len) {
String result = { 0, 0 };
subkey_t ks;
int i, j;

getSubKeys(key, ks);
/* reverse the subkeys */
for (i = 1; i < 9; ++i) {
for (j = 0; j < 6; ++j) {
ubyte temp = ks[i][j];
ks[i][j] = ks[17 - i][j];
ks[17 - i][j] = temp;
}
}

result.data = (ubyte*)malloc(len);
memcpy(result.data, message, len);
result.len = len;
for (i = 0; i < result.len; i += 8) {
processMessage(&result.data[i], ks, &result.data[i]);
}

return result;
}

/*
* Convienience method for showing the round trip processing of a message
*/
void driver(const key_t key, const ubyte *message, int len) {
String encoded, decoded;
char buffer[128];

printBytes(key, KEY_LEN, buffer);
printf("Key     : %s\n", buffer);

printBytes(message, len, buffer);
printf("Message : %s\n", buffer);

encoded = encrypt(key, message, len);
printBytes(encoded.data, encoded.len, buffer);
printf("Encoded : %s\n", buffer);

decoded = decrypt(key, encoded.data, encoded.len);
printBytes(decoded.data, decoded.len, buffer);
printf("Decoded : %s\n\n", buffer);

/* release allocated memory */
if (encoded.len > 0) {
free(encoded.data);
encoded.data = 0;
}
if (decoded.len > 0) {
free(decoded.data);
decoded.data = 0;
}
}

int main() {
const key_t keys[] = {
{0x13, 0x34, 0x57, 0x79, 0x9B, 0xBC, 0xDF, 0xF1},
{0x0E, 0x32, 0x92, 0x32, 0xEA, 0x6D, 0x0D, 0x73},
{0x0E, 0x32, 0x92, 0x32, 0xEA, 0x6D, 0x0D, 0x73}
};
const ubyte message1[] = { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF };
const ubyte message2[] = { 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87 };
const ubyte message3[] = { 0x59, 0x6F, 0x75, 0x72, 0x20, 0x6C, 0x69, 0x70, 0x73, 0x20, 0x61, 0x72, 0x65, 0x20, 0x73, 0x6D, 0x6F, 0x6F, 0x74, 0x68, 0x65, 0x72, 0x20, 0x74, 0x68, 0x61, 0x6E, 0x20, 0x76, 0x61, 0x73, 0x65, 0x6C, 0x69, 0x6E, 0x65, 0x0D, 0x0A };
int len;

len = sizeof(message1) / sizeof(ubyte);
driver(keys[0], message1, len);

len = sizeof(message2) / sizeof(ubyte);
driver(keys[1], message2, len);

len = sizeof(message3) / sizeof(ubyte);
driver(keys[2], message3, len);
return 0;
}
```

{{out}}

```Key     : 133457799BBCDFF1
Message : 0123456789ABCDEF
Encoded : 85E813540F0AB405FDF2E174492922F8
Decoded : 0123456789ABCDEF

Key     : 0E329232EA6D0D73
Message : 8787878787878787
Encoded : 0000000000000000A913F4CB0BD30F97
Decoded : 8787878787878787

Key     : 0E329232EA6D0D73
Message : 596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A
Encoded : C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F53584997F922CCB5B068D99
Decoded : 596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A
```

## C++

{{trans|D}}

```#include <algorithm>
#include <array>
#include <bitset>
#include <iomanip>
#include <iostream>
#include <ostream>
#include <vector>

template <size_t N>
std::ostream& operator<<(std::ostream& out, std::bitset<N>& bs) {
// debug
for (int i = 0; i < N; i += 8) {
out << bs.test(i + 0) << bs.test(i + 1) << bs.test(i + 2) << bs.test(i + 3) << '_';
if (i + 7 < N) {
out << bs.test(i + 4) << bs.test(i + 5) << bs.test(i + 6) << bs.test(i + 7) << ' ';
} else {
out << "0000 ";
}
}
return out;
}

namespace DES {
typedef unsigned char ubyte;
typedef std::array<ubyte, 8> key_t;

namespace impl {
const int 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
};

const int 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
};

const int 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
};

const int E[] = {
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
};

const int S[][64] = {
{
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
},
{
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
},
{
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
},
{
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
},
{
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
},
{
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
},
{
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
},
{
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
}
};

const int P[] = {
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
};

const int IP2[] = {
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
};

const int SHIFTS[] = { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 };

std::bitset<64> toBitSet(const key_t& key) {
std::bitset<64> bs;
for (int i = 0; i < 8; ++i) {
bs.set(8 * i + 0, key[i] & 0x80);
bs.set(8 * i + 1, key[i] & 0x40);
bs.set(8 * i + 2, key[i] & 0x20);
bs.set(8 * i + 3, key[i] & 0x10);

bs.set(8 * i + 4, key[i] & 0x08);
bs.set(8 * i + 5, key[i] & 0x04);
bs.set(8 * i + 6, key[i] & 0x02);
bs.set(8 * i + 7, key[i] & 0x01);
}
return bs;
}

template <size_t N>
std::bitset<N * 8> toBitSet(const std::array<ubyte, N>& src) {
std::bitset<N * 8> bs;
for (int i = 0; i < N; ++i) {
bs.set(8 * i + 0, src[i] & 0x80);
bs.set(8 * i + 1, src[i] & 0x40);
bs.set(8 * i + 2, src[i] & 0x20);
bs.set(8 * i + 3, src[i] & 0x10);

bs.set(8 * i + 4, src[i] & 0x08);
bs.set(8 * i + 5, src[i] & 0x04);
bs.set(8 * i + 6, src[i] & 0x02);
bs.set(8 * i + 7, src[i] & 0x01);
}
return bs;
}

template <size_t N>
std::array<ubyte, N / 8> toArray(const std::bitset<N>& bs) {
std::array<ubyte, N / 8> arr;
std::fill_n(arr.begin(), N / 8, 0);
for (int i = 0; i < N / 8; ++i) {
arr[i] |= (bs[8 * i + 0] << 7);
arr[i] |= (bs[8 * i + 1] << 6);
arr[i] |= (bs[8 * i + 2] << 5);
arr[i] |= (bs[8 * i + 3] << 4);

arr[i] |= (bs[8 * i + 4] << 3);
arr[i] |= (bs[8 * i + 5] << 2);
arr[i] |= (bs[8 * i + 6] << 1);
arr[i] |= (bs[8 * i + 7] << 0);
}
return arr;
}

template <size_t N>
std::bitset<N> shiftLeft(const std::bitset<N>& bs, int len, int times) {
std::bitset<N> output;
for (int i = 0; i < len; ++i) {
output[i] = bs[i];
}
for (int t = 0; t < times; ++t) {
int temp = output[0];
for (int i = 1; i < len; ++i) {
output[i - 1] = output[i];
}
output[len - 1] = temp;
}
return output;
}

std::array<std::bitset<48>, 17> getSubKeys(const key_t& key) {
std::array<std::bitset<56>, 17> c;
std::array<std::bitset<28>, 17> d;
std::bitset<56> kp;

auto k = toBitSet(key);

/* permute 'key' using table PC1 */
for (int i = 0; i < 56; ++i) {
kp[i] = k[PC1[i] - 1];
}

/* split 'kp' in half and process the resulting series of 'c' and 'd' */
for (int i = 0; i < 28; ++i) {
c[0][i] = kp[i];
d[0][i] = kp[i + 28];
}

/* shift the components of c and d */
for (int i = 1; i < 17; ++i) {
c[i] = shiftLeft(c[i - 1], 28, SHIFTS[i - 1]);
d[i] = shiftLeft(d[i - 1], 28, SHIFTS[i - 1]);
}

/* merge 'd' into 'c' */
for (int i = 1; i < 17; ++i) {
for (int j = 28; j < 56; ++j) {
c[i][j] = d[i][j - 28];
}
}

/* form the sub-keys and store them in 'ks'
* permute 'c' using table PC2 */
std::array<std::bitset<48>, 17> ks;
for (int i = 1; i < 17; ++i) {
for (int j = 0; j < 48; ++j) {
ks[i][j] = c[i][PC2[j] - 1];
}
}

return ks;
}

std::bitset<32> f(const std::bitset<48>& ks, std::bitset<32>& r) {
// permute 'r' using table E
std::bitset<48> er;
for (int i = 0; i < 48; ++i) {
er[i] = r[E[i] - 1];
}

// xor 'er' with 'ks' and store back into 'er'
er ^= ks;

// process 'er' six bits at a time and store resulting four bits in 'sr'
std::bitset<32> sr;
for (int i = 0; i < 8; ++i) {
int j = 6 * i;
std::bitset<6> b;
for (int k = 0; k < 6; ++k) {
b[k] = er[j + k] != 0;
}
int row = 2 * b[0] + b[5];
int col = 8 * b[1] + 4 * b[2] + 2 * b[3] + b[4];
int m = S[i][row * 16 + col];   // apply table s
int n = 1;
while (m > 0) {
int p = m % 2;
sr[(i + 1) * 4 - n] = (p == 1);
m /= 2;
n++;
}
}

// permute sr using table P
std::bitset<32> sp;
for (int i = 0; i < 32; ++i) {
sp[i] = sr[P[i] - 1];
}
return sp;
}

std::array<ubyte, 8> processMessage(const std::array<std::bitset<48>, 17>& ks, const std::array<ubyte, 8>& message) {
auto m = toBitSet(message);

// permute 'message' using table IP
std::bitset<64> mp;
for (int i = 0; i < 64; ++i) {
mp[i] = m[IP[i] - 1];
}

// split 'mp' in half and process the resulting series of 'l' and 'r
std::array<std::bitset<32>, 17> left;
std::array<std::bitset<32>, 17> right;
for (int i = 0; i < 32; ++i) {
left[0][i] = mp[i];
right[0][i] = mp[i + 32];
}
for (int i = 1; i < 17; ++i) {
left[i] = right[i - 1];
auto fs = f(ks[i], right[i - 1]);
left[i - 1] ^= fs;
right[i] = left[i - 1];
}

// amalgamate r[16] and l[16] (in that order) into 'e'
std::bitset<64> e;
for (int i = 0; i < 32; ++i) {
e[i] = right[16][i];
}
for (int i = 32; i < 64; ++i) {
e[i] = left[16][i - 32];
}

// permute 'e' using table IP2 ad return result as a hex string
std::bitset<64> ep;
for (int i = 0; i < 64; ++i) {
ep[i] = e[IP2[i] - 1];
}
}
}

std::vector<ubyte> encrypt(const key_t& key, const std::vector<ubyte>& message) {
auto ks = impl::getSubKeys(key);
std::vector<ubyte> m(message);

// pad the message so there are 8 byte groups
ubyte padByte = 8 - m.size() % 8;
for (int i = 0; i < padByte; ++i) {
}

std::vector<ubyte> sb;
for (size_t i = 0; i < m.size(); i += 8) {
std::array<ubyte, 8> part;
std::copy_n(m.begin() + i, 8, part.begin());
part = impl::processMessage(ks, part);
std::copy(part.begin(), part.end(), std::back_inserter(sb));
}

return sb;
}

std::vector<ubyte> decrypt(const key_t& key, const std::vector<ubyte>& encoded) {
auto ks = impl::getSubKeys(key);
// reverse the subkeys
std::reverse(ks.begin() + 1, ks.end());

std::vector<ubyte> decoded;
for (int i = 0; i < encoded.size(); i += 8) {
std::array<ubyte, 8> part;
std::copy_n(encoded.begin() + i, 8, part.begin());
part = impl::processMessage(ks, part);
std::copy(part.begin(), part.end(), std::back_inserter(decoded));
}

// remove the padding bytes from the decoded message
return decoded;
}

std::ostream& operator<<(std::ostream& os, const key_t& key) {
os << std::setfill('0') << std::uppercase << std::hex;
for (int i = 0; i < 8; ++i) {
os << std::setw(2) << (int)key[i];
}
return os;
}

std::ostream& operator<<(std::ostream& os, const std::vector<ubyte>& msg) {
os << std::setfill('0') << std::uppercase << std::hex;
for (auto b : msg) {
os << std::setw(2) << (int)b;
}
return os;
}
}

int main() {
using namespace std;
using namespace DES;

key_t keys[] = {
{0x13, 0x34, 0x57, 0x79, 0x9B, 0xBC, 0xDF, 0xF1},
{0x0E, 0x32, 0x92, 0x32, 0xEA, 0x6D, 0x0D, 0x73},
{0x0E, 0x32, 0x92, 0x32, 0xEA, 0x6D, 0x0D, 0x73}
};
vector<vector<ubyte>> messages = {
{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
{0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87},
{0x59, 0x6F, 0x75, 0x72, 0x20, 0x6C, 0x69, 0x70, 0x73, 0x20, 0x61, 0x72, 0x65, 0x20, 0x73, 0x6D, 0x6F, 0x6F, 0x74, 0x68, 0x65, 0x72, 0x20, 0x74, 0x68, 0x61, 0x6E, 0x20, 0x76, 0x61, 0x73, 0x65, 0x6C, 0x69, 0x6E, 0x65, 0x0D, 0x0A}
};

for (int i = 0; i < 3; ++i) {
cout << "Key     : " << keys[i] << '\n';
cout << "Message : " << messages[i] << '\n';

auto encoded = encrypt(keys[i], messages[i]);
cout << "Encoded : " << encoded << endl;

auto decoded = decrypt(keys[i], encoded);
cout << "Decoded : " << decoded << endl;

cout << '\n';
}

return 0;
}
```

{{out}}

```Key     : 133457799BBCDFF1
Message : 0123456789ABCDEF
Encoded : 85E813540F0AB405FDF2E174492922F8
Decoded : 0123456789ABCDEF

Key     : 0E329232EA6D0D73
Message : 8787878787878787
Encoded : 0000000000000000A913F4CB0BD30F97
Decoded : 8787878787878787

Key     : 0E329232EA6D0D73
Message : 596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A
Encoded : C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F53584997F922CCB5B068D99
Decoded : 596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A
```

## C#

```using System;
using System.IO;
using System.Security.Cryptography;

namespace DES {
class Program {
//Taken from https://stackoverflow.com/a/311179
static string ByteArrayToString(byte[] ba) {
return BitConverter.ToString(ba).Replace("-", "");
}

//Modified from https://stackoverflow.com/q/4100996
//The passwordBytes parameter must be 8 bytes long
static byte[] Encrypt(byte[] messageBytes, byte[] passwordBytes) {
byte[] iv = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

// Set encryption settings -- Use password for both key and init. vector
DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
CryptoStreamMode mode = CryptoStreamMode.Write;

// Set up streams and encrypt
MemoryStream memStream = new MemoryStream();
CryptoStream cryptoStream = new CryptoStream(memStream, transform, mode);
cryptoStream.Write(messageBytes, 0, messageBytes.Length);
cryptoStream.FlushFinalBlock();

// Read the encrypted message from the memory stream
byte[] encryptedMessageBytes = new byte[memStream.Length];
memStream.Position = 0;

return encryptedMessageBytes;
}

//Modified from https://stackoverflow.com/q/4100996
//The passwordBytes parameter must be 8 bytes long
static byte[] Decrypt(byte[] encryptedMessageBytes, byte[] passwordBytes) {
byte[] iv = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

// Set encryption settings -- Use password for both key and init. vector
DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
CryptoStreamMode mode = CryptoStreamMode.Write;

// Set up streams and decrypt
MemoryStream memStream = new MemoryStream();
CryptoStream cryptoStream = new CryptoStream(memStream, transform, mode);
cryptoStream.Write(encryptedMessageBytes, 0, encryptedMessageBytes.Length);
cryptoStream.FlushFinalBlock();

// Read decrypted message from memory stream
byte[] decryptedMessageBytes = new byte[memStream.Length];
memStream.Position = 0;

return decryptedMessageBytes;
}

static void Main(string[] args) {
byte[] keyBytes = new byte[] { 0x0e, 0x32, 0x92, 0x32, 0xea, 0x6d, 0x0d, 0x73 };
byte[] plainBytes = new byte[] { 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87 };

byte[] encStr = Encrypt(plainBytes, keyBytes);
Console.WriteLine("Encoded: {0}", ByteArrayToString(encStr));

byte[] decBytes = Decrypt(encStr, keyBytes);
Console.WriteLine("Decoded: {0}", ByteArrayToString(decBytes));
}
}
}
```

{{out}}

```Encoded: 0000000000000000A913F4CB0BD30F97
Decoded: 8787878787878787
```

## D

{{trans|kotlin}}

```import std.array;
import std.bitmanip;
import std.stdio;

immutable 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
];

immutable 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
];

immutable 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
];

immutable E = [
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
];

immutable S = [
[
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
],
[
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
],
[
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
],
[
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
],
[
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
],
[
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
],
[
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
],
[
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
]
];

immutable P = [
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
];

immutable IP2 = [
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
];

immutable SHIFTS = [1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1];

BitArray bitArrayOfSize(uint count) {
bool[] buffer = new bool[count];
return BitArray(buffer);
}

ubyte[] encrypt(const ubyte[] key, const ubyte[] message) in {
assert(key.length == 8, "Incorrect key size");
} body {
BitArray[] ks = getSubKeys(key);
ubyte[] m = message.dup;

// pad the message so there are 8 byte groups
ubyte padByte = 8 - m.length % 8;
}
assert(m.length % 8 == 0);

ubyte[] sb;
foreach (i; 0..m.length / 8) {
auto j = i * 8;
auto enc = processMessage(m[j..j+8], ks);
sb ~= enc;
}

return sb;
}

ubyte[] decrypt(const ubyte[] key, const ubyte[] encoded) in {
assert(key.length == 8, "Incorrect key size");
} body {
BitArray[] ks = getSubKeys(key);
// reverse the subkeys
foreach (i; 1..9) {
auto temp = ks[i];
ks[i] = ks[17 - i];
ks[17 - i] = temp;
}

ubyte[] decoded;
foreach (i; 0..encoded.length / 8) {
auto j = i * 8;
auto dec = processMessage(encoded[j..j+8], ks);
decoded ~= dec;
}

// remove the padding bytes from the decoded message
ubyte padByte = decoded[\$ - 1];

return decoded;
}

private BitArray[] getSubKeys(const ubyte[] key) in {
assert(key.length == 8);
} body {
auto k = key.toBitArray();

// permute 'key' using table PC1
auto kp = bitArrayOfSize(56);
foreach (i; 0..56) {
kp[i] = k[PC1[i] - 1];
}

// split 'kp' in half and process the resulting series of 'c' and 'd'
BitArray[] c;
BitArray[] d;
foreach (_; 0..18) {
c ~= bitArrayOfSize(56);
d ~= bitArrayOfSize(28);
}
foreach (i; 0..28) {
c[0][i] = kp[i];
d[0][i] = kp[i + 28];
}
foreach (i; 1..17) {
c[i - 1].shiftLeft(SHIFTS[i - 1], 28, c[i]);
d[i - 1].shiftLeft(SHIFTS[i - 1], 28, d[i]);
}

// merge 'd' into 'c'
foreach (i; 1..17) {
foreach (j; 28..56) {
c[i][j] = d[i][j - 28];
}
}

// form the sub-keys and store them in 'ks'
BitArray[] ks;
foreach (_; 0..17) {
ks ~= bitArrayOfSize(48);
}

// permute 'c' using table PC2
foreach (i; 1..17) {
foreach (j; 0..48) {
ks[i][j] = c[i][PC2[j] - 1];
}
}

return ks;
}

private ubyte[] processMessage(const ubyte[] message, BitArray[] ks) {
auto m = message.toBitArray();

// permute 'message' using table IP
auto mp = bitArrayOfSize(64);
foreach (i; 0..64) {
mp[i] = m[IP[i] - 1];
}

// split 'mp' in half and process the resulting series of 'l' and 'r
BitArray[] left;
BitArray[] right;
foreach (_; 0..17) {
left ~= bitArrayOfSize(32);
right ~= bitArrayOfSize(32);
}
foreach (i; 0..32) {
left[0][i] = mp[i];
right[0][i] = mp[i + 32];
}
foreach (i; 1..17) {
left[i] = right[i - 1];
auto fs = f(right[i - 1], ks[i]);
left[i - 1] ^= fs;
right[i] = left[i - 1];
}

// amalgamate r[16] and l[16] (in that order) into 'e'
auto e = bitArrayOfSize(64);
foreach (i; 0..32) {
e[i] = right[16][i];
}
foreach (i; 32..64) {
e[i] = left[16][i - 32];
}

// permute 'e' using table IP2 ad return result as a hex string
auto ep = bitArrayOfSize(64);
foreach (i; 0..64) {
ep[i] = e[IP2[i] - 1];
}
return ep.toByteArray();
}

private BitArray toBitArray(const ubyte[] byteArr) {
auto bitArr = bitArrayOfSize(8 * byteArr.length);
for (int i=0; i<byteArr.length; i++) {
bitArr[8*i+0] = (byteArr[i] & 128) != 0;
bitArr[8*i+1] = (byteArr[i] & 64) != 0;
bitArr[8*i+2] = (byteArr[i] & 32) != 0;
bitArr[8*i+3] = (byteArr[i] & 16) != 0;
bitArr[8*i+4] = (byteArr[i] & 8) != 0;
bitArr[8*i+5] = (byteArr[i] & 4) != 0;
bitArr[8*i+6] = (byteArr[i] & 2) != 0;
bitArr[8*i+7] = (byteArr[i] & 1) != 0;
}
return bitArr;
}

ubyte[] toByteArray(const ref BitArray bitArr) {
auto len = bitArr.length / 8;
ubyte[] byteArr = new ubyte[len];
foreach (i; 0..len) {
byteArr[i]  = bitArr[8 * i + 0] << 7;
byteArr[i] |= bitArr[8 * i + 1] << 6;
byteArr[i] |= bitArr[8 * i + 2] << 5;
byteArr[i] |= bitArr[8 * i + 3] << 4;
byteArr[i] |= bitArr[8 * i + 4] << 3;
byteArr[i] |= bitArr[8 * i + 5] << 2;
byteArr[i] |= bitArr[8 * i + 6] << 1;
byteArr[i] |= bitArr[8 * i + 7] << 0;
}
return byteArr;
}

void shiftLeft(const ref BitArray self, int times, int len, ref BitArray output) {
for (int i=0; i<=len; i++) {
output[i] = self[i];
}
for (int t=1; t<=times; t++) {
auto temp = output[0];
for (int i=1; i<=len; i++) {
output[i - 1] = output[i];
}
output[len - 1] = temp;
}
}

private BitArray f(const ref BitArray r, const ref BitArray ks) {
// permute 'r' using table E
auto er = bitArrayOfSize(48);
foreach (i; 0..48) {
er[i] = r[E[i] - 1];
}

// xor 'er' with 'ks' and store back into 'er'
er ^= ks;

// process 'er' six bits at a time and store resulting four bits in 'sr'
auto sr = bitArrayOfSize(32);
foreach (i; 0..8) {
auto j = i * 6;
auto b = new int[6];
foreach (k; 0..6) {
b[k] = (er[j+k] != 0) ? 1 : 0;
}
auto row = 2 * b[0] + b[5];
auto col = 8 * b[1] + 4 * b[2] + 2 * b[3] + b[4];
int m = S[i][row * 16 + col];   // apply table s
int n = 1;
while (m > 0) {
auto p = m % 2;
sr[(i + 1) * 4 - n] = (p == 1);
m /= 2;
n++;
}
}

// permute sr using table P
auto sp = bitArrayOfSize(32);
foreach (i; 0..32) {
sp[i] = sr[P[i] - 1];
}
return sp;
}

void main() {
immutable ubyte[][] keys = [
[cast(ubyte)0x13, 0x34, 0x57, 0x79, 0x9B, 0xBC, 0xDF, 0xF1],
[0x0E, 0x32, 0x92, 0x32, 0xEA, 0x6D, 0x0D, 0x73],
[0x0E, 0x32, 0x92, 0x32, 0xEA, 0x6D, 0x0D, 0x73],
];
immutable ubyte[][] messages = [
[cast(ubyte)0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF],
[0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87],
[0x59, 0x6F, 0x75, 0x72, 0x20, 0x6C, 0x69, 0x70, 0x73, 0x20, 0x61, 0x72, 0x65, 0x20, 0x73, 0x6D, 0x6F, 0x6F, 0x74, 0x68, 0x65, 0x72, 0x20, 0x74, 0x68, 0x61, 0x6E, 0x20, 0x76, 0x61, 0x73, 0x65, 0x6C, 0x69, 0x6E, 0x65, 0x0D, 0x0A],
];
assert(keys.length == messages.length);

foreach (i; 0..messages.length) {
writefln("Key     : %(%02X%)", keys[i]);
writefln("Message : %(%02X%)", messages[i]);
ubyte[] encoded = encrypt(keys[i], messages[i]);
writefln("Encoded : %(%02X%)", encoded);
ubyte[] decoded = decrypt(keys[i], encoded);
writefln("Decoded : %(%02X%)", decoded);
writeln;
}
}

```

{{out}}

```Key     : 133457799BBCDFF1
Message : 0123456789ABCDEF
Encoded : 85E813540F0AB405FDF2E174492922F8
Decoded : 0123456789ABCDEF

Key     : 0E329232EA6D0D73
Message : 8787878787878787
Encoded : 0000000000000000A913F4CB0BD30F97
Decoded : 8787878787878787

Key     : 0E329232EA6D0D73
Message : 596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A
Encoded : C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F53584997F922CCB5B068D99
Decoded : 596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A
```

```open System
open System.Security.Cryptography
open System.IO

let ByteArrayToString ba =
ba |> Array.map (fun (b : byte) -> b.ToString("X2")) |> String.Concat

// Configure encryption settings
let iv = Array.zeroCreate 8
let provider = new DESCryptoServiceProvider()

// Setup streams and encrypt
let memStream = new MemoryStream()
let cryptoStream = new CryptoStream(memStream, transform, CryptoStreamMode.Write)
cryptoStream.Write(messageBytes, 0, messageBytes.Length)
cryptoStream.FlushFinalBlock()

// Read the encrypted message from the stream
let encryptedMessageBytes = Array.zeroCreate ((int) memStream.Length)
memStream.Position <- 0L

// Return the encrypted bytes
encryptedMessageBytes

// Configure encryption settings
let iv = Array.zeroCreate 8
let provider = new DESCryptoServiceProvider()

// Setup streams and decrypt
let memStream = new MemoryStream()
let cryptoStream = new CryptoStream(memStream, transform, CryptoStreamMode.Write)
cryptoStream.Write(encryptedBytes, 0, encryptedBytes.Length)
cryptoStream.FlushFinalBlock()

// Read the message from the stream
let messageBytes = Array.zeroCreate ((int) memStream.Length)
memStream.Position <- 0L

// Return the encrypted bytes
messageBytes

[<EntryPoint>]
let main _ =
let keyBytes = [|0x0euy; 0x32uy; 0x92uy; 0x32uy; 0xeauy; 0x6duy; 0x0duy; 0x73uy|]
let plainbytes = [|0x87uy; 0x87uy; 0x87uy; 0x87uy; 0x87uy; 0x87uy; 0x87uy; 0x87uy|]

let encStr = Encrypt keyBytes plainbytes
printfn "Encoded: %s" (ByteArrayToString encStr)

let decBytes = Decrypt keyBytes encStr
printfn "Decoded: %s" (ByteArrayToString decBytes)

0 // return an integer exit code
```

{{out}}

```Encoded: 0000000000000000A913F4CB0BD30F97
Decoded: 8787878787878787
```

## FreeBASIC

```' version 20-01-2019
' compile with: fbc -s console

Dim Shared As String * 48 subkey_k()
Dim Shared As String code2

Sub make_subkeys(key As String)

Dim As UInteger<32> pc_1(55) => _
{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}

Dim As UInteger<32> pc_2(47) => _
{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}

Dim As UInteger<32> number_of_left_shl(1 To 16) => _
{1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1}

Dim As UInteger<32> p1 = Val("&H" + Left(key, 8)), _
p2 = Val("&H" + Right(key, 8))
Dim As String * 64 str_key = Bin(p1, 32) + Bin(p2, 32)
Dim As String * 56 perm_key
Dim As UInteger<32> i, k, s = 1
ReDim subkey_k(1 To 16)

For i = 0 To 55
perm_key[i] = str_key[pc_1(i) -1]
Next

Dim As String cd, c0 = Left(perm_key, 28), d0 = Right(perm_key, 28)
c0 += c0 : d0 += d0

For i = 1 To 16
s += number_of_left_shl(i)
cd = Mid(c0, s, 28) + Mid(d0, s, 28)
For k = 0 To 47
subkey_k(i)[k] = cd[pc_2(k) -1]
Next
Next

End Sub

Function encode_64bit_data(message As String) As String

Dim As UInteger<32> ip(63) =>   _
{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}

Dim As UInteger<32> ip_inv(63) => _
{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}

Dim As UInteger<32> e(47) => _
{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}

Dim As UInteger<32> p(31) => _
{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}

Dim As UInteger<32> S1_8(7, 63) => _
{{14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7,  _  's1
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}, _
_
{15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10,  _  's2
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}, _
_
{10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8,  _  's3
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}, _
_
{7, 13, 14, 3,  0,  6,  9, 10,  1, 2, 8,  5, 11, 12,  4, 15,  _  's4
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}, _
_
{2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13, 0, 14,  9,  _  's5
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}, _
_
{12,  1, 10, 15, 9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11,  _  's6
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}, _
_
{4, 11,  2, 14, 15, 0,  8, 13,  3, 12, 9,  7,  5, 10, 6,  1,  _  's7
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}, _
_
{13,  2,  8, 4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7,  _  's8
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}}

Dim As UInteger<32> i, i1, k, tmp1, tmp2, tmp3
tmp1 = Val("&H"+ Left(message,8)) : tmp2 = Val("&H" + Right(message,8))
Dim As String * 64 Str1, str_message = Bin(tmp1, 32) + Bin(tmp2, 32)
Dim As String * 48 temp
Dim As String * 32 l(16), r(16), Str2
Dim As String Str3

For i = 0 To 63
Str1[i] = str_message[ip(i) -1]
Next

l(0) = Left(Str1, 32)
r(0) = Right(Str1, 32)

For i = 1 To 16
i1 = i -1
l(i) = r(i1)

For k = 0 To 47
temp[k] = ((subkey_k(i)[k] + r(i1)[e(k) -1]) And 1) + Asc("0")
Next

Str3 = ""
For k = 0 To 42 Step 6
tmp1 = Val("&B" + Mid(temp, k +1, 1) + Mid(temp, k +6, 1))
tmp2 = Val("&B" + Mid(temp, k +2, 4))
Str3 = Str3 + Bin(s1_8(k \ 6 , tmp1 * 16 + tmp2), 4)
Next

For k = 0 To 31
r(i)[k] = ((l(i1)[k] + Str3[p(k) -1]) And 1) + Asc("0")
Next
Next

Str3 = r(16) + l(16)
For i = 0 To 63
Str1[i] = Str3[ip_inv(i) -1]
Next

tmp1 = Val("&B" + Left(Str1,32))
tmp2 = Val("&B" + Right(Str1,32))
Return Hex(tmp1, 8) + Hex(tmp2, 8)

End Function

Function convert(key As String, message As String) As String

Dim As UInteger<32> i, l

If Len(key) = 16 Then
make_subkeys(key)
If code2 = "decode" Then
For i = 1 To 8
Swap subkey_k(i), subkey_k(16 +1 -i)
Next
End If
Else
Beep
Print "wrong key length, program stops"
End
End If

Do Until InStr(message, " ") = 0
i = InStr(message, " ")
message = Left(message, i -1) + Mid(message, i +1)
Loop

l = Len(message) \ 16
If Len(message) Mod 16 <> 0 Then
l += 1
message = Left((message + String(16, "0")), l * 16)
End If

For i = 0 To l -1
answer = encode_64bit_data(Mid(message, i * 16 +1, 16))
Next

If code2 = "decode" And InStrRev(answer, "0D0A0") <> 0 Then
crypto = RTrim(crypto, "0")
End If

Return crypto

End Function

Function encode(key As String, message As String) As String

code2 = "encode"
Return convert(key, message)

End Function

Function decode(key As String, message As String) As String

code2 = "decode"
Return convert(key, message)

End Function

' ------=< MAIN >=------

Dim As String key, message, crypto, answer

message = "0123456789ABCDEF"
key = "133457799BBCDFF1"
Print "    key "; key
Print "   text "; message
Print

message = "8787878787878787"
key = "0E329232EA6D0D73"
Print "    key "; key
Print "   text "; message
Print

message = "596F7572206C6970 732061726520736D 6F6F746865722074" + _
" 68616E2076617365 6C696E650D0A"
key = "0E329232EA6D0D73"
Print "    key "; key
Print "   text "; message

' empty keyboard buffer
While Inkey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
End
```

{{out}}

```    key 133457799BBCDFF1
text 0123456789ABCDEF
encoded 85E813540F0AB405
decoded 0123456789ABCDEF

key 0E329232EA6D0D73
text 8787878787878787
encoded 0000000000000000
decoded 8787878787878787

key 0E329232EA6D0D73
text 596F7572206C6970 732061726520736D 6F6F746865722074 68616E2076617365 6C696E650D0A
encoded C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F5358499828AC9B453E0E653
decoded 596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A
```

## Go

'''Library solution:'''

```package main

import (
"crypto/des"
"encoding/hex"
"fmt"
"log"
)

func main() {
key, err := hex.DecodeString("0e329232ea6d0d73")
if err != nil {
log.Fatal(err)
}
c, err := des.NewCipher(key)
if err != nil {
log.Fatal(err)
}
src, err := hex.DecodeString("8787878787878787")
if err != nil {
log.Fatal(err)
}
dst := make([]byte, des.BlockSize)
c.Encrypt(dst, src)
fmt.Printf("%x\n", dst)
}
```

{{out}}

```
0000000000000000

```

## Java

{{trans|Kotlin}}

```import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class DataEncryptionStandard {
private static byte[] toHexByteArray(String self) {
byte[] bytes = new byte[self.length() / 2];
for (int i = 0; i < bytes.length; ++i) {
bytes[i] = ((byte) Integer.parseInt(self.substring(i * 2, i * 2 + 2), 16));
}
return bytes;
}

private static void printHexBytes(byte[] self, String label) {
System.out.printf("%s: ", label);
for (byte b : self) {
int bb = (b >= 0) ? ((int) b) : b + 256;
String ts = Integer.toString(bb, 16);
if (ts.length() < 2) {
ts = "0" + ts;
}
System.out.print(ts);
}
System.out.println();
}

public static void main(String[] args) throws Exception {
String strKey = "0e329232ea6d0d73";
byte[] keyBytes = toHexByteArray(strKey);
SecretKeySpec key = new SecretKeySpec(keyBytes, "DES");
Cipher encCipher = Cipher.getInstance("DES");
encCipher.init(Cipher.ENCRYPT_MODE, key);
String strPlain = "8787878787878787";
byte[] plainBytes = toHexByteArray(strPlain);
byte[] encBytes = encCipher.doFinal(plainBytes);
printHexBytes(encBytes, "Encoded");

Cipher decCipher = Cipher.getInstance("DES");
decCipher.init(Cipher.DECRYPT_MODE, key);
byte[] decBytes = decCipher.doFinal(encBytes);
printHexBytes(decBytes, "Decoded");
}
}
```

{{out}}

```Encoded: 0000000000000000a913f4cb0bd30f97
Decoded: 8787878787878787
```

## Kotlin

===Version 1 (using library functions)=== Presumably, one can use library functions to demonstrate DES as it would be very tedious to implement it from scratch:

```// version 1.1.3

import javax.crypto.Cipher
import javax.crypto.spec.SecretKeySpec

fun String.toHexByteArray(): ByteArray {
val bytes = ByteArray(this.length / 2)
for (i in 0 until bytes.size) {
bytes[i] = this.substring(i * 2, i * 2 + 2).toInt(16).toByte()
}
return bytes
}

fun ByteArray.printHexBytes(label: String) {
print("\$label: ")
for (b in this) {
val bb = if (b >= 0) b.toInt() else b + 256
}
println()
}

fun main(args: Array<String>) {
val strKey = "0e329232ea6d0d73"
val keyBytes = strKey.toHexByteArray()
val key = SecretKeySpec(keyBytes, "DES")
val encCipher = Cipher.getInstance("DES")
encCipher.init(Cipher.ENCRYPT_MODE, key)
val strPlain = "8787878787878787"
val plainBytes = strPlain.toHexByteArray()
val encBytes = encCipher.doFinal(plainBytes)
encBytes.printHexBytes("Encoded")

val decCipher = Cipher.getInstance("DES")
decCipher.init(Cipher.DECRYPT_MODE, key)
val decBytes = decCipher.doFinal(encBytes)
decBytes.printHexBytes("Decoded")
}
```

{{out}} Note that the 'encoded' output includes 8 bytes of padding using the default JVM DES implementation:

```
Encoded: 0000000000000000a913f4cb0bd30f97
Decoded: 8787878787878787

```

===Version 2 (from scratch)=== It wasn't as tedious as I expected due to the admirably clear article linked to above:

```// version 1.1.3

import java.util.BitSet

object DES {

private val PC1 = intArrayOf(
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
)

private val PC2 = intArrayOf(
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
)

private val IP = intArrayOf(
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
)

private val E = intArrayOf(
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
)

private val S = arrayOf(
intArrayOf(
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
),

intArrayOf(
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
),

intArrayOf(
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
),

intArrayOf(
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
),

intArrayOf(
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
),

intArrayOf(
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
),

intArrayOf(
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
),

intArrayOf(
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
)
)

private val P = intArrayOf(
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
)

private val IP2 = intArrayOf(
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
)

private val SHIFTS = intArrayOf(1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1)

fun encrypt(key: String, message: String): String {
val ks = getSubKeys(key)
var m = message
val r = m.length % 16 // check if multiple of 16 hex digits
val rem = 8 - r / 2
val remStr = "%02X".format(rem)
for (i in 1..rem) {
m += remStr
}
assert(m.length % 16 == 0)

val sb = StringBuilder()
for (i in 0 until m.length / 16) {
val j = i * 16
val enc = processMessage(m.substring(j, j + 16), ks)
sb.append(enc)
}
return sb.toString()
}

fun decrypt(key: String, encoded: String): String {
val ks = getSubKeys(key)
// reverse the subkeys
for (i in 1..8) {
val temp = ks[i]
ks[i] = ks[17 - i]
ks[17 - i] = temp
}
val sb = StringBuilder()
for (i in 0 until encoded.length / 16) {
val j = i * 16
val dec = processMessage(encoded.substring(j, j + 16), ks)
sb.append(dec)
}
val padByte = sb[sb.length - 1] - '0'
return sb.substring(0, sb.length - 2 * padByte)
}

private fun getSubKeys(key: String): Array<BitSet> {
val k = key.toLittleEndianBitSet()

// permute 'key' using table PC1
val kp = BitSet(56)
for (i in 0..55) kp[i] = k[PC1[i] - 1]

// split 'kp' in half and process the resulting series of 'c' and 'd'
val c = Array(17) { BitSet(56) }
val d = Array(17) { BitSet(28) }
for (i in 0..27) c[0][i] = kp[i]
for (i in 0..27) d[0][i] = kp[i + 28]
for (i in 1..16) {
c[i - 1].shiftLeft(SHIFTS[i - 1], 28, c[i])
d[i - 1].shiftLeft(SHIFTS[i - 1], 28, d[i])
}

// merge 'd' into 'c'
for (i in 1..16) {
for (j in 28..55) c[i][j] = d[i][j - 28]
}

// form the sub-keys and store them in 'ks'
val ks = Array(17) { BitSet(48) }

// permute 'c' using table PC2
for (i in 1..16) {
for (j in 0..47) ks[i][j] = c[i][PC2[j] - 1]
}

return ks
}

private fun processMessage(message: String, ks: Array<BitSet>): String {
val m = message.toLittleEndianBitSet()

// permute 'message' using table IP
val mp = BitSet(64)
for (i in 0..63) {
mp[i] = m[IP[i] - 1]
}

// split 'mp' in half and process the resulting series of 'l' and 'r
val l = Array(17) { BitSet(32) }
val r = Array(17) { BitSet(32) }
for (i in 0..31) l[0][i] = mp[i]
for (i in 0..31) r[0][i] = mp[i + 32]
for (i in 1..16) {
l[i] = r[i - 1]
val fs = f(r[i - 1], ks[i])
l[i - 1].xor(fs)
r[i] = l[i - 1]
}

// amalgamate r[16] and l[16] (in that order) into 'e'
val e = BitSet(64)
for (i in 0..31) e[i] = r[16][i]
for (i in 32..63) e[i] = l[16][i - 32]

// permute 'e' using table IP2 ad return result as a hex string
val ep = BitSet(64)
for (i in 0..63) ep[i] = e[IP2[i] - 1]
return ep.toHexString(64)
}

/* assumes a hex string receiver */
private fun String.toLittleEndianBitSet(): BitSet {
val bs = BitSet(this.length * 4)
for ((i, c) in this.withIndex()) {
for (j in 0..3) bs[i * 4 + j] = (s[j] == '1')
}
return bs
}

/* assumes a little-endian bitset receiver */
private fun BitSet.toHexString(len: Int): String {
val size = len / 4
val sb = StringBuilder(size)
val ba = ByteArray(4)
for (i in 0 until size) {
for (j in 0..3) ba[j] = if (this[i * 4 + j]) 1 else 0
val c = "%X".format(ba[0] * 8 + ba[1] * 4 + ba[2] * 2 + ba[3])
sb.append(c)
}
return sb.toString()
}

private fun BitSet.shiftLeft(times: Int, len: Int, out: BitSet) {
for (i in 0 until len) out[i] = this[i]
for (t in 1..times) {
val temp = out[0]
for (i in 1 until len) out[i - 1] = out[i]
out[len - 1] = temp
}
}

private fun f(r: BitSet, ks: BitSet): BitSet {
// permute 'r' using table E
val er = BitSet(48)
for (i in 0..47) er[i] = r[E[i] - 1]

// xor 'er' with 'ks' and store back into 'er'
er.xor(ks)

// process 'er' six bits at a time and store resulting four bits in 'sr'
val sr = BitSet(32)
for (i in 0..7) {
val j = i * 6
val b = IntArray(6)
for (k in 0..5) b[k] = if (er[j + k]) 1 else 0
val row = 2 * b[0] + b[5]
val col = 8 * b[1] + 4 * b[2] + 2 * b[3] + b[4]
var m = S[i][row * 16 + col]   // apply table S
var n = 1
while (m > 0) {
val p = m % 2
sr[(i + 1) * 4 - n] = (p == 1)
m /= 2
n++
}
}

// permute sr using table P
val sp = BitSet(32)
for (i in 0..31) sp[i] = sr[P[i] - 1]
return sp
}
}

fun main(args: Array<String>) {
val keys = listOf("133457799BBCDFF1", "0E329232EA6D0D73", "0E329232EA6D0D73")
val messages = listOf(
"0123456789ABCDEF",
"8787878787878787",
"596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A"
)
for (i in 0..2) {
println("Key     : \${keys[i]}")
println("Message : \${messages[i]}")
val encoded = DES.encrypt(keys[i], messages[i])
println("Encoded : \$encoded")
val decoded = DES.decrypt(keys[i], encoded)
println("Decoded : \$decoded")
println()
}
}
```

{{out}}

```Key     : 133457799BBCDFF1
Message : 0123456789ABCDEF
Encoded : 85E813540F0AB405FDF2E174492922F8
Decoded : 0123456789ABCDEF

Key     : 0E329232EA6D0D73
Message : 8787878787878787
Encoded : 0000000000000000A913F4CB0BD30F97
Decoded : 8787878787878787

Key     : 0E329232EA6D0D73
Message : 596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A
Encoded : C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F53584997F922CCB5B068D99
Decoded : 596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A
```

```MODULE DataEncryptionStandard;
FROM DES IMPORT DES,Key1,Create,Destroy,EncryptECB,DecryptECB;
FROM FormatString IMPORT FormatString;

PROCEDURE PrintHexBytes(str : ARRAY OF BYTE; limit : INTEGER);
VAR
buf : ARRAY[0..7] OF CHAR;
i,v : INTEGER;
BEGIN
i := 0;
WHILE i<limit DO
v := ORD(str[i]);
IF v < 16 THEN
WriteString("0")
END;
FormatString("%h", buf, v);
WriteString(buf);
INC(i);
END
END PrintHexBytes;

TYPE BA = ARRAY[0..15] OF BYTE;
VAR
plain,encrypt : BA;
key : ARRAY[0..0] OF Key1;
cipher : DES;
BEGIN
(* Account for the padding *)
plain := BA{87H, 87H, 87H, 87H, 87H, 87H, 87H, 87H, 8, 8, 8, 8, 8, 8, 8, 8};

key[0] := Key1{0EH, 32H, 92H, 32H, 0EAH, 6DH, 0DH, 73H};
cipher := Create(key);

WriteString("plain:   ");
PrintHexBytes(plain, 8);
WriteLn;

WriteString("encrypt: ");
PrintHexBytes(encrypt, 16);
WriteLn;

WriteString("plain:   ");
PrintHexBytes(plain, 8);
WriteLn;

Destroy(cipher);
END DataEncryptionStandard.
```

{{out}}

```plain:   8787878787878787
encrypt: 0000000000000000A913F4CB0BD30F97
plain:   8787878787878787
```

## Perl 6

This is mainly a translation from the Phix entry, with an additional example on UTF-8. Regarding the many conversions among different number/string formats, small (and hopefully reusable ) helper routines are created to serve the purpose. Update 20190323: After a bug fixed an example does behave correctly and is now in line with the results from the C, D, Kotlin and Phix entries. By the way it seems ''.comb'' handle "\r\n" inconsistently, why? [https://pastebin.com/d7dBpYkL] Update 20190325: Thanks to SqrtNegInf for pointing out that the answer is already in the documentation.[https://docs.perl6.org/type/Str#routine_chomp], [https://docs.perl6.org/language/newline] {{trans|Phix}}

```#!/usr/bin/env perl6

use v6.d;
use experimental :pack;

my \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
>; # Permuted choice 1 (PC-1) - Parity Drop Table

my \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
>; # Permuted choice 2 (PC-2) - Key Compression Table

my \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
>; # Initial permutation (IP)

my \IP2 = <
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
>; # Final permutation (IP⁻¹)

my \S = ( <
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
> , <
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
> , <
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
> , <
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
> , <
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
> , <
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
> , <
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
> , <
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
> ); # 8 Substitution boxes, each replaces a 6-bit input with a 4-bit output

my \P = <
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
>; # Permutation (P), shuffles the bits of a 32-bit half-block

# Expansion function (E), expand 32-bit half-block to 48 bits
my \E = flat 32,1..5,4..9,8..13,12..17,16..21,20..25,24..29,28..32,1;

my \SHIFTS = < 1 1 2 2 2 2 2 2 1 2 2 2 2 2 2 1 >; # schedule of left shifts

## Helper subs

sub b2h (\b) { [~] map { .encode('iso-8859-1').unpack('H*') }, b.comb };

# convert UTF8s to bytes
sub u2b (\u) { [~] map { .chr }, @( [~] map { .encode('utf8') }, u.comb) };

sub h2u (\h) { pack("H" x h.chars/2, h ~~ m:g/../).decode('utf8') };

sub q2h (\q) { [~] map { :2(\$_.Str).fmt('%X') }, q ~~ m:g/..../ };

# convert every two quadbits to bytes
sub q2b (\q) { map { :2(\$_.Str) }, q ~~ m:g/. ** 8/ };

# trun a 16 digit hexadecimal str to a 64 bits list
sub h2bits (\h) { ([~] map { :16(\$_).base(2).fmt('%04s') }, h.comb).split("")[1..64] };

sub infix:<⥀>(\a is copy, \b) { a.append: a.shift for ^b ; a } # XOR addition

sub h2bytes (\h) { [~] map { :16(\$_.Str).chr }, h ~~ m:g/../ };

# s is 16 digit hexadecimal str, M is a permuation matrix/vector
sub map64(\s, \M) { my \b = h2bits s; map { b[\$_-1] }, M; }

## Core subs

sub get_subkeys(Str \key --> Seq) { # return a Seq with 16 bit vectors
my \Kₚ = map64 key, PC1; # drop parity bits
my @C = Kₚ[0..27] ; my @D = Kₚ[28..55]; # perform bits rotation next
my \CD = map { [ flat @C ⥀= SHIFTS[\$_], @D ⥀= SHIFTS[\$_] ]}, ^16;
return map { map { CD[\$_][PC2[\$^a]-1] }, ^48 }, ^16; # key compression rounds
}

sub ƒ (List \R is copy, Seq \Kₙ is copy --> Seq) {
my @er = map { Kₙ[\$_] +^ R[E[\$_]-1] }, ^48;
my @sr = flat map { # Sₙ(Bₙ) loop, process @er six bits at a time
((S.[\$_][([~] @er[\$_*6,\$_*6+5]).parse-base(2)*16+([~]
@er[\$_*6+1 .. \$_*6+4]).parse-base(2)]).fmt('%04b').split(""))[1..4]
}, ^8;
return map { @sr[\$_-1] }, P;
}

sub process_block(Str \message, \K is copy --> Str) { # return 8 quadbits
my \mp = map64 (b2h message) , IP; # turn message to hex then map to bits
my @L = mp[0..31]; my @R = mp[32..63];
my (@Lₙ , @Rₙ); # then apply 16 iterations with function ƒ
{ @Lₙ = @R; @Rₙ = @L Z+^ ƒ @R, K[\$_]; @L = @Lₙ; @R = @Rₙ } for ^16;
my \res = flat @R, @L; # reverse and join the final L₁₆ and R₁₆
return [~] map { res[\$_-1] }, IP2 ; # inverse of the initial permutation
}

sub des(Str \key, Str \$msg is copy, Bool \DECODE --> Str) { # return hexdecimal
my @K; my \length = \$msg.encode('iso-8859-1').bytes;
if ( DECODE and length % 8 ) { # early exit, avoid the subkeys computation
die "Message must be in multiples of 8 bytes"
} else {
@K = DECODE ?? reverse get_subkeys key !! get_subkeys key
}
{  my \P = 8 - length % 8; # number of pad bytes
\$msg ~= P.chr x P ; # CMS style padding as per RFC 1423 & RFC 5652
} unless DECODE;

my \$quad ~= process_block substr(\$msg,\$_,8), @K for
0, 8 … \$msg.encode('iso-8859-1').bytes-8;

{  my @decrypt = q2b \$quad; # quadbits to a byte code point list
@decrypt.pop xx @decrypt.tail; # remove padding
return b2h ( [~] map { .chr } , @decrypt )
} if DECODE ;

}

say "Encryption examples: ";
say des "133457799BBCDFF1", h2bytes("0123456789ABCDEF"), False;
say des "0E329232EA6D0D73", h2bytes("8787878787878787"), False;
say des "0E329232EA6D0D73", "Your lips are smoother than vaseline", False;
say des "0E329232EA6D0D73", "Your lips are smoother than vaseline\r\n", False;
say des "0E329232EA6D0D73", u2b("BMP: こんにちは ; Astral plane: 𝒳𝒴𝒵"), False;

say "Decryption examples: ";
say des "133457799BBCDFF1", h2bytes("85E813540F0AB405FDF2E174492922F8"), True;
say des "0E329232EA6D0D73", h2bytes("0000000000000000A913F4CB0BD30F97"), True;
say h2bytes des "0E329232EA6D0D73", h2bytes("C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F535849980A2E7453703513E"), True;
say h2bytes des "0E329232EA6D0D73", h2bytes("C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F53584997F922CCB5B068D99"), True;
say h2u des "0E329232EA6D0D73", h2bytes("C040FB6A6E72D7C36D60CA9B9A35EB38D3194468AD808103C28E33AEF0B268D0E0366C160B028DDACF340003DCA8969343EBBD289DB94774"), True;
```

{{out}}

```Encryption examples:
85E813540F0AB405FDF2E174492922F8
0000000000000000A913F4CB0BD30F97
C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F535849980A2E7453703513E
C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F53584997F922CCB5B068D99
Decryption examples:
0123456789abcdef
8787878787878787
Your lips are smoother than vaseline
Your lips are smoother than vaseline

BMP: こんにちは ; Astral plane: 𝒳𝒴𝒵
```

## Phix

{{trans|Kotlin}} Implementation following the excellent paper by J. Orlin Grabbe, as linked above. Like Kotlin version 2, this expands values into more manageable bit arrays, which are easier to debug/verify, probably sidestep a few fiddly endian issues, and certainly simplify bit-wise permutations.

```-- demo\rosetta\Data_Encryption_Standard.exw
constant 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},

SHIFTS = {1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1},

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},

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},

E = {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},

S = {{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},
{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},
{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},
{ 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},
{ 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},
{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},
{ 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},
{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}},

P = {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},

IP_1 = {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}

function map64(string s, sequence P)
if length(s)!=8 then ?9/0 end if -- 64 bits
string b = "", res = ""
for i=1 to length(s) do
b &= sprintf("%08b",s[i])
end for
for i=1 to length(P) do
res &= b[P[i]]-'0'
end for
return res
end function

function get_subkeys(string key)
string kp = map64(key,PC1)
sequence ks = repeat(repeat('\0',48),16)
for i=1 to 16 do
integer shift = SHIFTS[i]
kp = kp[shift+1..28]&kp[1..shift]&
kp[shift+29..56]&kp[29..shift+28]
for j=1 to 48 do ks[i][j] = kp[PC2[j]] end for
end for
return ks
end function

function f(sequence r, kn)
string er = "", sr = "", sp = ""
for i=1 to 48 do er &= r[E[i]] xor kn[i] end for
-- process 'er' six bits at a time and store resulting four bits in 'sr'
for i=1 to 8 do
integer j = (i-1)*6+1,
k = sum(sq_mul(er[j..j+5],{32,8,4,2,1,16}))+1
sr &= sprintf("%04b",S[i][k])
end for
for i=1 to 32 do sp &= sr[P[i]]-'0' end for
return sp
end function

function process_block(string message, sequence k)
string mp = map64(message,IP),
{l,r} = {mp[1..32],mp[33..64]}
for n=1 to 16 do
{l,r} = {r,sq_xor(l,f(r,k[n]))}
end for
string e = r&l, res = ""
for i=0 to 63 by 8 do
integer byte = 0
for bit=1 to 8 do
byte = byte*2+e[IP_1[i+bit]]
end for
res &= byte
end for
return res
end function

function des(string key, message, bool decode=false)
sequence k = get_subkeys(key)
if decode then
k = reverse(k)
else
-- (match the C#/Java/Modula-2 library implementations, in
--  case we're swapping messages with something using them)
integer p = 8-mod(length(message),8)
for i=1 to p do message &= p end for
end if
-- check message is multiple of 8 bytes (= 64 bits)
if mod(length(message),8)!=0 then ?9/0 end if
string res = ""
for i=1 to length(message) by 8 do
res &= process_block(message[i..i+7], k)
end for
if decode then
-- ditto
res = res[1..length(res)-res[\$]]
end if
return res
end function

constant TESTS = {{x"133457799BBCDFF1", x"0123456789ABCDEF", "85E813540F0AB405FDF2E174492922F8"},
{x"0E329232EA6D0D73", x"8787878787878787", "0000000000000000A913F4CB0BD30F97"},
{x"0E329232EA6D0D73",
--                 x"596F7572206C6970732061726520736D6F6F74686572207468616E20766173656C696E650D0A",
"Your lips are smoother than vaseline\r\n",
"C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F53584997F922CCB5B068D99"}}

function as_hex(string s)
string res = ""
for i=1 to length(s) do
res &= sprintf("%02x",s[i])
end for
return res
end function

for i=1 to length(TESTS) do
string {key,msg,expect} = TESTS[i],
keytxt = as_hex(key),
msgtxt = iff(i!=3?as_hex(msg):sprint(msg)),
encoded = des(key, msg),
enctxt = as_hex(encoded),
error = iff(enctxt=expect?"":"\n********* "&expect&" expected"),
decoded = des(key, encoded, true),
dectxt = iff(i!=3?as_hex(decoded):sprint(decoded)),
derror = iff(decoded=msg?"":" *** error")
printf(1,"Key     : %s\n",{keytxt})
printf(1,"Message : %s\n",{msgtxt})
printf(1,"Encoded : %s%s\n",{enctxt,error})
printf(1,"Decoded : %s%s\n\n",{dectxt,derror})
end for
```

{{out}}

```
Key     : 133457799BBCDFF1
Message : 0123456789ABCDEF
Encoded : 85E813540F0AB405FDF2E174492922F8
Decoded : 0123456789ABCDEF

Key     : 0E329232EA6D0D73
Message : 8787878787878787
Encoded : 0000000000000000A913F4CB0BD30F97
Decoded : 8787878787878787

Key     : 0E329232EA6D0D73
Message : "Your lips are smoother than vaseline\r\n"
Encoded : C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F53584997F922CCB5B068D99
Decoded : "Your lips are smoother than vaseline\r\n"

```

## Python

implemented like in the article linked in description.

really good article btw

```#!/usr/bin/python
#!/usr/bin/python

# Permutation tables and Sboxes
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
)
IP_INV = (
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
)
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
)
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
)

E  = (
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
)

Sboxes = {
0: (
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
),
1: (
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
),
2: (
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
),
3: (
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
),
4: (
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
),
5: (
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
),
6: (
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
),
7: (
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
)
}

P = (
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
)

def encrypt(msg, key, decrypt=False):
# only encrypt single blocks
assert isinstance(msg, int) and isinstance(key, int)
assert not msg.bit_length() > 64
assert not key.bit_length() > 64

# permutate by table PC1
key = permutation_by_table(key, 64, PC1) # 64bit -> PC1 -> 56bit

# split up key in two halves
# generate the 16 round keys
C0 = key >> 28
D0 = key & (2**28-1)
round_keys = generate_round_keys(C0, D0) # 56bit -> PC2 -> 48bit

msg_block = permutation_by_table(msg, 64, IP)
L0 = msg_block >> 32
R0 = msg_block & (2**32-1)

# apply thr round function 16 times in following scheme (feistel cipher):
L_last = L0
R_last = R0
for i in range(1,17):
if decrypt: # just use the round keys in reversed order
i = 17-i
L_round = R_last
R_round = L_last ^ round_function(R_last, round_keys[i])
L_last = L_round
R_last = R_round

# concatenate reversed
cipher_block = (R_round<<32) + L_round

# final permutation
cipher_block = permutation_by_table(cipher_block, 64, IP_INV)

return cipher_block

def round_function(Ri, Ki):
# expand Ri from 32 to 48 bit using table E
Ri = permutation_by_table(Ri, 32, E)

# xor with round key
Ri ^= Ki

# split Ri into 8 groups of 6 bit
Ri_blocks = [((Ri & (0b111111 << shift_val)) >> shift_val) for shift_val in (42,36,30,24,18,12,6,0)]

# interpret each block as address for the S-boxes
for i, block in enumerate(Ri_blocks):
# grab the bits we need
row = ((0b100000 & block) >> 4) + (0b1 & block)
col = (0b011110 & block) >> 1
# sboxes are stored as one-dimensional tuple, so we need to calc the index this way
Ri_blocks[i] = Sboxes[i][16*row+col]

# pack the blocks together again by concatenating
Ri_blocks = zip(Ri_blocks, (28,24,20,16,12,8,4,0))
Ri = 0
for block, lshift_val in Ri_blocks:
Ri += (block << lshift_val)

# another permutation 32bit -> 32bit
Ri = permutation_by_table(Ri, 32, P)

return Ri

def permutation_by_table(block, block_len, table):
# quick and dirty casting to str
block_str = bin(block)[2:].zfill(block_len)
perm = []
for pos in range(len(table)):
perm.append(block_str[table[pos]-1])
return int(''.join(perm), 2)

def generate_round_keys(C0, D0):
# returns dict of 16 keys (one for each round)

round_keys = dict.fromkeys(range(0,17))
lrot_values = (1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1)

# left-rotation function
lrot = lambda val, r_bits, max_bits: \
(val << r_bits%max_bits) & (2**max_bits-1) | \
((val & (2**max_bits-1)) >> (max_bits-(r_bits%max_bits)))

# initial rotation
C0 = lrot(C0, 0, 28)
D0 = lrot(D0, 0, 28)
round_keys[0] = (C0, D0)

# create 16 more different key pairs
for i, rot_val in enumerate(lrot_values):
i+=1
Ci = lrot(round_keys[i-1][0], rot_val, 28)
Di = lrot(round_keys[i-1][1], rot_val, 28)
round_keys[i] = (Ci, Di)

# round_keys[1] for first round
#           [16] for 16th round
# dont need round_keys[0] anymore, remove
del round_keys[0]

# now form the keys from concatenated CiDi 1<=i<=16 and by apllying PC2
for i, (Ci, Di) in round_keys.items():
Ki = (Ci << 28) + Di
round_keys[i] = permutation_by_table(Ki, 56, PC2) # 56bit -> 48bit

return round_keys

k = 0x0e329232ea6d0d73 # 64 bit
k2 = 0x133457799BBCDFF1
m = 0x8787878787878787
m2 = 0x0123456789ABCDEF

def prove(key, msg):
print('key:       {:x}'.format(key))
print('message:   {:x}'.format(msg))
cipher_text = encrypt(msg, key)
print('encrypted: {:x}'.format(cipher_text))
plain_text = encrypt(cipher_text, key, decrypt=True)
print('decrypted: {:x}'.format(plain_text))

prove(k, m)
print('----------')
prove(k2, m2)

```

{{Out}} Note: This is just the algorithm for single 64-bit blocks. No padding or block chipher operation mode

```key:       e329232ea6d0d73
message:   8787878787878787
encrypted: 0
decrypted: 8787878787878787
----------
key:       133457799bbcdff1
message:   123456789abcdef
encrypted: 85e813540f0ab405
decrypted: 123456789abcdef
```

## REXX

Implementation of the algorithm described in the cited article.

Decryption is now supported as well

```/* REXX for the sake of some platforms such as good old iron */
Parse Upper Arg action
Select
When action='?' Then Do
Say "REXX des shows     how '8787878787878787'X is encoded to"
Say "                       '000000000000000'X"
Say "REXX des DEC shows how '000000000000000'X is decoded to"
Say "                       '8787878787878787'X"
Exit
End
When action='' | action='ENC' Then
encode=1
When action='' | action='DEC' Then
encode=0
Otherwise Do
Say 'Invalid argument' action '(must be ENC or DEC or omitted)'
Exit
End
End
o='abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890.-'
Call init
Call debug 'tr_pc_1='tr_pc_1
Call debug 'tr_ip  ='tr_ip
Call debug 'tr_p   ='tr_p
Call debug 'tr_ipa ='tr_ipa

kx='0e329232ea6d0d73'
If encode Then
mx='8787878787878787'
Else
mx='0000000000000000'
k=x2b(kx)
m=x2b(mx)
Say 'Message:' mx
Say 'Key    :' kx
ka=translate(tr_pc_1,k,o)
Call debug 'ka='ka
Parse Var ka c.0 +28 d.0
shifts='1 1 2 2 2 2 2 2 1 2 2 2 2 2 2 1'
Do i=1 To 16
ip=i-1
c.i=shift(c.ip,word(shifts,i))
d.i=shift(d.ip,word(shifts,i))
End
Do i=1 To 16
cd.i=c.i||d.i
k.i=translate(tr_pc_2,cd.i,o)
Call debug 'k.'i'='k.i
End

If encode=0 Then Do /*revert the subkeys */
Do i=1 To 16
j=17-i
kd.i=k.j
End
Do i=1 To 16
k.i=kd.i
End
End

IP=translate(tr_ip,m,o)
Call debug 'ip='ip

Parse Var ip l.0 +32 r.0

Call debug 'E(R.0)='E(R.0)
Call debug 'k.1   ='k.1
t=xor(k.1,E(R.0))
Call debug 't     ='t
Call debug length(t)
zz=''
Do i=1 To 8
Parse Var t b +6 t
zz=zz||s(i,b)
End
Call debug 'zz='zz
f=translate(tr_p,zz,o)
Call debug 'f='f
r.1=xor(l.0,f)
Call debug 'r.1='r.1
l.1=r.0
Do j=2 To 16
ja=j-1
l.j=r.ja
z=xor(k.j,e(r.ja))
zz=''
Do i=1 To 8
Parse Var z b +6 z
zz=zz||s(i,b)
End
Call debug j zz
f=translate(tr_p,zz,o)
Call debug j f
r.j=xor(l.ja,f)
End
Call debug 'l.16='l.16
Call debug 'r.16='r.16

zzz=r.16||l.16
c=translate(tr_ipa,zzz,o)
Call debug c
Say 'Result :' b2x(c)
Exit

f: Procedure Expose s. o tr_p
Parse Arg r,k
z=xor(k,e(r))
zz=translate(tr_p,z,o)
Return zz

init:
PC_1='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'

tr_pc_1=''
Do i=1 To words(pc_1)
tr_pc_1=tr_pc_1||substr(o,word(pc_1,i),1)
End
tr_pc_1=tr_pc_1

kb=translate(tr_pc_1,k,o)
kc=strip(kb,,'*')

PC_2='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'
tr_pc_2=''
Do i=1 To words(pc_2)
tr_pc_2=tr_pc_2||substr(o,word(pc_2,i),1)
End

Do i=1 To 16
cd.i=c.i||d.i
k.i=translate(ok,cd.i,o)
Call debug 'k.'i'='k.i
End

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'
tr_ip=''
Do i=1 To words(IP)
tr_ip=tr_ip||substr(o,word(ip,i),1)
End

P='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'
tr_p=''
Do i=1 To words(p)
tr_p=tr_p||substr(o,word(p,i),1)
End

SM.1='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'
SM.2='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'
SM.3='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'
SM.4=' 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'
SM.5=' 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'
SM.6='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'
SM.7=' 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'
SM.8='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'
Do i=1 To 8
Do r=0 To 3
Do c=0 To 15
Parse Var sm.i s.i.r.c sm.i
End
End
End

ipa='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'
tr_ipa=''
Do i=1 To words(ipa)
tr_ipa=tr_ipa||substr(o,word(ipa,i),1)
End

Return

shift: Procedure
Parse Arg in,s
out=substr(in,s+1)left(in,s)
Return out

E: Procedure
Parse Arg s
esel='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'
r=''
Do i=1 To words(esel)
r=r||substr(s,word(esel,i),1)
End
Return r

xor: Procedure
Parse Arg u,v
r=''
Do i=1 To length(u)
cc=substr(u,i,1)substr(v,i,1)
r=r||(pos(cc,'01 10')>0)
End
Return r

s: Procedure Expose s.
Parse Arg i,b
Parse Var b r1 +1 c +4 r2
r=r1||r2
rb=num(r)
cb=num(c)
result=s.i.rb.cb
Return num2bits(result)

num: Procedure
Parse Arg s
res=0
Do i=1 To length(s)
Parse Var s c +1 s
res=2*res+c
End
Return res

num2bits: Procedure
Parse Arg n
nx=d2x(n)
r=''
Do i=1 To 4
dig=n//2
r=dig||r
n=n%2
End
Return r

debug: /* Say arg(1) */ Return
```

{{out}}

```I:\>rexx des2
Message: 8787878787878787
Key    : 0e329232ea6d0d73
Result : 0000000000000000

I:\>rexx des2 dec
Message: 0000000000000000
Key    : 0e329232ea6d0d73
Result : 8787878787878787
```

## Scala

```import javax.crypto.Cipher
import javax.crypto.spec.SecretKeySpec

object DataEncryptionStandard extends App {

private def toHexByteArray(self: String) = {
val bytes = new Array[Byte](self.length / 2)
for (i <- bytes.indices)
bytes(i) = Integer.parseInt(self.substring(i * 2, i * 2 + 2), 16).toByte

bytes
}

private def printHexBytes(self: Array[Byte], label: String): Unit = {
printf("%s: ", label)
for (b <- self) {
val bb = if (b >= 0) b.toInt else b + 256
var ts = Integer.toString(bb, 16)
if (ts.length < 2) ts = "0" + ts
print(ts)
}
println()
}

val strKey = "0e329232ea6d0d73"
val keyBytes = toHexByteArray(strKey)
val key = new SecretKeySpec(keyBytes, "DES")
val encCipher = Cipher.getInstance("DES")
encCipher.init(Cipher.ENCRYPT_MODE, key)
val strPlain = "8787878787878787"
val plainBytes = toHexByteArray(strPlain)
val encBytes = encCipher.doFinal(plainBytes)
printHexBytes(encBytes, "Encoded")
val decCipher = Cipher.getInstance("DES")
decCipher.init(Cipher.DECRYPT_MODE, key)
val decBytes = decCipher.doFinal(encBytes)
printHexBytes(decBytes, "Decoded")

}
```

{{Out}}See it running in your browser by [https://scastie.scala-lang.org/t6nGq1ebShKEA42LSIQ6Hg Scastie (JVM)].

## Symsyn

```pc1 : 56
: 48
: 40
: 32
: 24
: 16
: 8
: 0
: 57
: 49
: 41
: 33
: 25
: 17
: 9
: 1
: 58
: 50
: 42
: 34
: 26
: 18
: 10
: 2
: 59
: 51
: 43
: 35
: 62
: 54
: 46
: 38
: 30
: 22
: 14
: 6
: 61
: 53
: 45
: 37
: 29
: 21
: 13
: 5
: 60
: 52
: 44
: 36
: 28
: 20
: 12
: 4
: 27
: 19
: 11
: 3
Pc2 : 13
: 16
: 10
: 23
: 0
: 4
: 2
: 27
: 14
: 5
: 20
: 9
: 22
: 18
: 11
: 3
: 25
: 7
: 15
: 6
: 26
: 19
: 12
: 1
: 40
: 51
: 30
: 36
: 46
: 54
: 29
: 39
: 50
: 44
: 32
: 47
: 43
: 48
: 38
: 55
: 33
: 52
: 45
: 41
: 49
: 35
: 28
: 31
P : 15
: 6
: 19
: 20
: 28
: 11
: 27
: 16
: 0
: 14
: 22
: 25
: 4
: 17
: 30
: 9
: 1
: 7
: 23
: 13
: 31
: 26
: 2
: 8
: 18
: 12
: 29
: 5
: 21
: 10
: 3
: 24
Ebit : 31
: 0
: 1
: 2
: 3
: 4
: 3
: 4
: 5
: 6
: 7
: 8
: 7
: 8
: 9
: 10
: 11
: 12
: 11
: 12
: 13
: 14
: 15
: 16
: 15
: 16
: 17
: 18
: 19
: 20
: 19
: 20
: 21
: 22
: 23
: 24
: 23
: 24
: 25
: 26
: 27
: 28
: 27
: 28
: 29
: 30
: 31
: 0
DesIP : 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
: 56
: 48
: 40
: 32
: 24
: 16
: 8
: 0
: 58
: 50
: 42
: 34
: 26
: 18
: 10
: 2
: 60
: 52
: 44
: 36
: 28
: 20
: 12
: 4
: 62
: 54
: 46
: 38
: 30
: 22
: 14
: 6
DesIPIV : 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
: 32
: 0
: 40
: 8
: 48
: 16
: 56
: 24
DesS1 :  14
:  0
:  4
:  15
:  13
:  7
:  1
:  4
:  2
:  14
:  15
:  2
:  11
:  13
:  8
:  1
:  3
:  10
:  10
:  6
:  6
:  12
:  12
:  11
:  5
:  9
:  9
:  5
:  0
:  3
:  7
:  8
:  4
:  15
:  1
:  12
:  14
:  8
:  8
:  2
:  13
:  4
:  6
:  9
:  2
:  1
:  11
:  7
:  15
:  5
:  12
:  11
:  9
:  3
:  7
:  14
:  3
:  10
:  10
:  0
:  5
:  6
:  0
:  13
S2 :  15
:  3
:  1
:  13
:  8
:  4
:  14
:  7
:  6
:  15
:  11
:  2
:  3
:  8
:  4
:  14
:  9
:  12
:  7
:  0
:  2
:  1
:  13
:  10
:  12
:  6
:  0
:  9
:  5
:  11
:  10
:  5
:  0
:  13
:  14
:  8
:  7
:  10
:  11
:  1
:  10
:  3
:  4
:  15
:  13
:  4
:  1
:  2
:  5
:  11
:  8
:  6
:  12
:  7
:  6
:  12
:  9
:  0
:  3
:  5
:  2
:  14
:  15
:  9
S3 :  10
:  13
:  0
:  7
:  9
:  0
:  14
:  9
:  6
:  3
:  3
:  4
:  15
:  6
:  5
:  10
:  1
:  2
:  13
:  8
:  12
:  5
:  7
:  14
:  11
:  12
:  4
:  11
:  2
:  15
:  8
:  1
:  13
:  1
:  6
:  10
:  4
:  13
:  9
:  0
:  8
:  6
:  15
:  9
:  3
:  8
:  0
:  7
:  11
:  4
:  1
:  15
:  2
:  14
:  12
:  3
:  5
:  11
:  10
:  5
:  14
:  2
:  7
:  12
S4 :  7
:  13
:  13
:  8
:  14
:  11
:  3
:  5
:  0
:  6
:  6
:  15
:  9
:  0
:  10
:  3
:  1
:  4
:  2
:  7
:  8
:  2
:  5
:  12
:  11
:  1
:  12
:  10
:  4
:  14
:  15
:  9
:  10
:  3
:  6
:  15
:  9
:  0
:  0
:  6
:  12
:  10
:  11
:  1
:  7
:  13
:  13
:  8
:  15
:  9
:  1
:  4
:  3
:  5
:  14
:  11
:  5
:  12
:  2
:  7
:  8
:  2
:  4
:  14
S5 :  2
:  14
:  12
:  11
:  4
:  2
:  1
:  12
:  7
:  4
:  10
:  7
:  11
:  13
:  6
:  1
:  8
:  5
:  5
:  0
:  3
:  15
:  15
:  10
:  13
:  3
:  0
:  9
:  14
:  8
:  9
:  6
:  4
:  11
:  2
:  8
:  1
:  12
:  11
:  7
:  10
:  1
:  13
:  14
:  7
:  2
:  8
:  13
:  15
:  6
:  9
:  15
:  12
:  0
:  5
:  9
:  6
:  10
:  3
:  4
:  0
:  5
:  14
:  3
S6 :  12
:  10
:  1
:  15
:  10
:  4
:  15
:  2
:  9
:  7
:  2
:  12
:  6
:  9
:  8
:  5
:  0
:  6
:  13
:  1
:  3
:  13
:  4
:  14
:  14
:  0
:  7
:  11
:  5
:  3
:  11
:  8
:  9
:  4
:  14
:  3
:  15
:  2
:  5
:  12
:  2
:  9
:  8
:  5
:  12
:  15
:  3
:  10
:  7
:  11
:  0
:  14
:  4
:  1
:  10
:  7
:  1
:  6
:  13
:  0
:  11
:  8
:  6
:  13
S7 :  4
:  13
:  11
:  0
:  2
:  11
:  14
:  7
:  15
:  4
:  0
:  9
:  8
:  1
:  13
:  10
:  3
:  14
:  12
:  3
:  9
:  5
:  7
:  12
:  5
:  2
:  10
:  15
:  6
:  8
:  1
:  6
:  1
:  6
:  4
:  11
:  11
:  13
:  13
:  8
:  12
:  1
:  3
:  4
:  7
:  10
:  14
:  7
:  10
:  9
:  15
:  5
:  6
:  0
:  8
:  15
:  0
:  14
:  5
:  2
:  9
:  3
:  2
:  12
S8 :  13
:  1
:  2
:  15
:  8
:  13
:  4
:  8
:  6
:  10
:  15
:  3
:  11
:  7
:  1
:  4
:  10
:  12
:  9
:  5
:  3
:  6
:  14
:  11
:  5
:  0
:  0
:  14
:  12
:  9
:  7
:  2
:  7
:  2
:  11
:  1
:  4
:  14
:  1
:  7
:  9
:  4
:  12
:  10
:  14
:  8
:  2
:  13
:  0
:  15
:  6
:  12
:  10
:  9
:  13
:  0
:  15
:  3
:  3
:  5
:  5
:  6
:  8
:  11
DesShifts :  1
:  1
:  2
:  2
:  2
:  2
:  2
:  2
:  1
:  2
:  2
:  2
:  2
:  2
:  2
:  1
DesHex : 0
:   0
:   0
:   0
:   0
:   0
:   0
:   1
:   0
:   0
:   1
:   0
:   0
:   0
:   1
:   1
:   0
:   1
:   0
:   0
:   0
:   1
:   0
:   1
:   0
:   1
:   1
:   0
:   0
:   1
:   1
:   1
:   1
:   0
:   0
:   0
:   1
:   0
:   0
:   1
:   1
:   0
:   1
:   0
:   1
:   0
:   1
:   1
:   1
:   1
:   0
:   0
:   1
:   1
:   0
:   1
:   1
:   1
:   1
:   0
:   1
:   1
:   1
:   1

DesC     : 28 0
DesD     : 28 0
DesL     : 32 0
DesR     : 32 0
DesL1    : 32 0
DesR1    : 32 0
DesEK    : 48 0
DesK     : 768 0
DesWds   : 64 0

DesI     : 0
DesJ     : 0
DesJJ    : 0xf000
DesIter  : 0
DesSNum  : 0
OldDesKeyW : -1
DesKeyW  : 0
DesDataW : 0
DesKey   = DesKeyW
DesData  = DesDataW
K : 0
Kc = K

kprime : x'0e329232ea6d0d73'

dprime : x'8787878787878787'

| Program Starts Here

kprime deskey         | Load encryption key
dprime desdata        | Load data to be encrypted
call dodeskey         | Perform key setup
call encryptdes       | Encrypt data
desdata \$s            | Move encrypted data to string
unpackhex \$s          | Unpack to display
\$s []                 | Display
stop

| End of Program

Data2Wds
63 DesJJ
7 DesI
if DesI GE 0
DesData.DesI D
DesJ
if DesJ LE 7
and 1 D D1
D1 DesWds.DesJJ
shr D 1
- DesJJ
+ DesJ
goif
endif
- DesI
goif
endif
return
Wds2Data
DesJJ
DesI
if DesI LE 7
DesJ
if DesJ LE 7
shl D 1
if DesWds.DesJJ NE 0
+ D
endif
+ DesJJ
+ DesJ
goif
endif
D DesData.DesI
+ DesI
goif
endif
return

Key2Wds
63 DesJJ
7 DesI
if DesI GE 0
DesKey.DesI K
DesJ
if DesJ LE 7
and K 1 K1
K1 DesWds.DesJJ
shr K 1
- DesJJ
+ DesJ
goif
endif
- DesI
goif
endif
return

func
DesI
if DesI LE 47
Ebit.DesI rx
DesR.rx DesEK.DesI
+ DesI
goif
endif
* 48 DesIter DesJ
DesI
if DesI LE 47
+ DesI DesJ IJ
xor DesEK.DesI DesK.IJ DesEK.DesI
+ DesI
goif
endif
DesI
DesSNum
if DesSNum LE 7
DesEK.DesI ss
shl ss 1
+ DesI
+ DesEK.DesI ss
shl ss 1
+ DesI
+ DesEK.DesI ss
shl ss 1
+ DesI
+ DesEK.DesI ss
shl ss 1
+ DesI
+ DesEK.DesI ss
shl ss 1
+ DesI
+ DesEK.DesI ss
+ DesI
DesSNum DesS1x
Shl DesS1x 6
+ ss DesS1x
DesS1.DesS1x DesHexx
shl DesHexx 2
DesSNum DesWdsx
shl DesWdsx 2
DesHex.DesHexx DesWds.DesWdsx 4
+ DesSNum
goif
endif
DesI
if DesI LE 31
P.DesI DesJ
DesWds.DesJ DesR.DesI
+ DesI
goif
endif
return

DoDesKey
if DesKeyW EQ OldDesKeyW
if DesJJ NE 0xf000
return
endif
endif
DesKeyW OldDesKeyW
call Key2Wds
DesI
if DesI LE 55
Pc1.DesI Pcx
DesWds.Pcx DesC.DesI
+ DesI
goif
endif
DesJJ
DesI
if DesI LE 15
DesC.0 DesWd
DesC.1 DesC 27
DesWd DesC.27
DesD.0 DesWd
DesD.1 DesD 27
DesWd DesD.27
if DesShifts.DesI EQ 2
DesC.0 DesWd
DesC.1 DesC 27
DesWd DesC.27
DesD.0 DesWd
DesD.1 DesD 27
DesWd DesD.27
endif
DesJ
if DesJ LE 47
Pc2.DesJ DesCx
DesC.DesCx DesK.DesJJ
+ DesJJ
+ DesJ
goif
endif
+ DesI
goif
endif
return

EncryptDes
Call Data2Wds
DesI
if DesI LE 63
DesIP.DesI DesWdsx
DesWds.DesWdsx DesL.DesI
+ DesI
goif
endif
DesIter
if DesIter LE 15
DesR DesL1 32
call func
DesJ
if DesJ LE 31
xor DesL.DesJ DesR.DesJ
+ DesJ
goif
endif
DesL1 DesL 32
+ DesIter
goif
endif
DesL DesR1 32
DesR DesL1 32
DesI
if DesI LE 63
DesIPIV.DesI DesL1x
DesL1.DesL1x DesWds.DesI
+ DesI
goif
endif

call Wds2Data
return

DecryptDes
Call Data2Wds
DesI
if DesI LE 63
DesIP.DesI DesWdsx
DesWds.DesWdsx DesL.DesI
+ DesI
goif
endif
15 DesIter
if DesIter GE 0
DesR DesL1 32
call func
DesJ
if DesJ LE 31
xor DesL.DesJ DesR.DesJ
+ DesJ
goif
endif
DesL1 DesL 32
- DesIter
goif
endif
DesL DesR1 32
DesR DesL1 32
DesI
if DesI LE 63
DesIPIV.DesI DesL1x
DesL1.DesL1x DesWds.DesI
+ DesI
goif
endif
call Wds2Data
return
```

A trivial solution using the des encryption instruction: key : x'0e329232ea6d0d73' data : x'8787878787878787'

edes key data | encrypt data with key data \$s | move data to string unpackhex \$s \$s | unpack \$s [] | output result - 0000000000000000

```
{{out}}

```txt
0000000000000000
```

## Visual Basic .NET

{{trans|C#}}

```Imports System.IO
Imports System.Security.Cryptography

Module Module1

'Taken from https://stackoverflow.com/a/311179
Function ByteArrayToString(ba As Byte()) As String
Return BitConverter.ToString(ba).Replace("-", "")
End Function

'Modified from https://stackoverflow.com/q/4100996
'The passwordBytes parameter must be 8 bytes long
Function Encrypt(messageBytes As Byte(), passwordBytes As Byte()) As Byte()
Dim iv As Byte() = {&H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0}

'Set encryption settings -- Use password for both key and init. vector
Dim provider As New DESCryptoServiceProvider
Dim mode = CryptoStreamMode.Write

'Set up streams and encrypt
Dim memStream As New MemoryStream
Dim cryptoStream As New CryptoStream(memStream, transform, mode)
cryptoStream.Write(messageBytes, 0, messageBytes.Length)
cryptoStream.FlushFinalBlock()

'Read the encrypted message from the memory stream
Dim encryptedMessageBytes(memStream.Length - 1) As Byte
memStream.Position = 0

Return encryptedMessageBytes
End Function

'Modified from https://stackoverflow.com/q/4100996
'The passwordBytes parameter must be 8 bytes long
Function Decrypt(encryptedMessageBytes As Byte(), passwordBytes As Byte()) As Byte()
Dim iv As Byte() = {&H0, &H0, &H0, &H0, &H0, &H0, &H0, &H0}

'Set encryption settings -- Use password for both key and init. vector
Dim provider As New DESCryptoServiceProvider
Dim mode = CryptoStreamMode.Write

'Set up streams and decrypt
Dim memStream As New MemoryStream
Dim cryptoStream As New CryptoStream(memStream, transform, mode)
cryptoStream.Write(encryptedMessageBytes, 0, encryptedMessageBytes.Length)
cryptoStream.FlushFinalBlock()

'Read decrypted message from memory stream
Dim decryptedMessageBytes(memStream.Length - 1) As Byte
memStream.Position = 0

Return decryptedMessageBytes
End Function

Sub Main()
Dim keyBytes As Byte() = {&HE, &H32, &H92, &H32, &HEA, &H6D, &HD, &H73}
Dim plainBytes As Byte() = {&H87, &H87, &H87, &H87, &H87, &H87, &H87, &H87}

Dim encStr = Encrypt(plainBytes, keyBytes)
Console.WriteLine("Encoded: {0}", ByteArrayToString(encStr))

Dim decStr = Decrypt(encStr, keyBytes)
Console.WriteLine("Decoded: {0}", ByteArrayToString(decStr))
End Sub

End Module
```

{{out}}

```Encoded: 0000000000000000A913F4CB0BD30F97
Decoded: 8787878787878787
```