37 lines
693 B
Factor
37 lines
693 B
Factor
|
USING: kernel math sequences namespaces math-contrib ;
|
||
|
|
IN: crypto-internals
|
||
|
|
|
||
|
|
! http://en.wikipedia.org/wiki/RC4_%28cipher%29
|
||
|
|
|
||
|
|
SYMBOL: i
|
||
|
|
SYMBOL: j
|
||
|
|
SYMBOL: s
|
||
|
|
SYMBOL: key
|
||
|
|
SYMBOL: l
|
||
|
|
|
||
|
|
|
||
|
|
! key scheduling algorithm, initialize s
|
||
|
|
: ksa ( -- )
|
||
|
|
256 [ ] map s set
|
||
|
|
0 j set
|
||
|
|
256 [
|
||
|
|
dup s get nth j get + over l get mod key get nth + 255 bitand j set
|
||
|
|
dup j get s get exchange
|
||
|
|
] repeat ;
|
||
|
|
|
||
|
|
: generate ( -- n )
|
||
|
|
i get 1+ 255 bitand i set
|
||
|
|
j get i get s get nth + 255 bitand j set
|
||
|
|
i get j get s get exchange
|
||
|
|
i get s get nth j get s get nth + 255 bitand s get nth ;
|
||
|
|
|
||
|
|
IN: crypto
|
||
|
|
|
||
|
|
: rc4 ( key -- )
|
||
|
|
[ key set ] keep
|
||
|
|
length l set
|
||
|
|
ksa
|
||
|
|
0 i set
|
||
|
|
0 j set ;
|
||
|
|
|