Data Encryption Standard: Difference between revisions

=={{header|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.

{{trans|Phix}}

<lang perl6>#!/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

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

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

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

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

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

# convert iso-8859-1 to hexadecimals

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) };

# convert hexadecimals to UTF-8

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

# convert quadbits to hex

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

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

# convert hexadecimals to bytes

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

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;

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

return [~] map { res[$_-1] }, IP2 ; # inverse of the initial permutation

}

sub des(Str \key, Str $msg is copy, Bool \DECODE --> Str) { # return hexdecimal

}

 

@decrypt.pop xx @decrypt.tail; # remove padding

return b2h ( [~] map { .chr } , @decrypt )

} if DECODE ;

return q2h $quad

}

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", 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;

{{out}}

<pre>Encryption examples:

0000000000000000A913F4CB0BD30F97

C0999FDDE378D7ED727DA00BCA5A84EE47F269A4D6438190D9D52F78F535849980A2E7453703513E

C040FB6A6E72D7C36D60CA9B9A35EB38D3194468AD808103C28E33AEF0B268D0E0366C160B028DDACF340003DCA8969343EBBD289DB94774

Decryption examples:

8787878787878787

Your lips are smoother than vaseline

BMP: こんにちは ; Astral plane: 𝒳𝒴𝒵</pre>