factor/extra/crypto/common/common.factor

56 lines
1.6 KiB
Factor

USING: arrays kernel io io.binary sbufs splitting grouping
strings sequences namespaces math math.parser parser
hints math.bitfields.lib assocs ;
IN: crypto.common
: w+ ( int int -- int ) + 32 bits ; inline
: (nth-int) ( string n -- int )
2 shift dup 4 + rot <slice> ; inline
: nth-int ( string n -- int ) (nth-int) le> ; inline
: nth-int-be ( string n -- int ) (nth-int) be> ; inline
: update ( num var -- ) [ w+ ] change ; inline
: calculate-pad-length ( length -- pad-length )
dup 56 < 55 119 ? swap - ;
: preprocess-plaintext ( string big-endian? -- padded-string )
#! pad 0x80 then 00 til 8 bytes left, then 64bit length in bits
>r >sbuf r> over [
HEX: 80 ,
dup length HEX: 3f bitand
calculate-pad-length 0 <string> %
length 3 shift 8 rot [ >be ] [ >le ] if %
] "" make over push-all ;
SYMBOL: bytes-read
SYMBOL: big-endian?
: pad-last-block ( str big-endian? length -- str )
[
rot %
HEX: 80 ,
dup HEX: 3f bitand calculate-pad-length 0 <string> %
3 shift 8 rot [ >be ] [ >le ] if %
] "" make 64 group ;
: update-old-new ( old new -- )
[ get >r get r> ] 2keep >r >r w+ dup r> set r> set ; inline
: slice3 ( n seq -- a b c ) >r dup 3 + r> <slice> first3 ;
: seq>2seq ( seq -- seq1 seq2 )
#! { abcdefgh } -> { aceg } { bdfh }
2 group flip dup empty? [ drop { } { } ] [ first2 ] if ;
: 2seq>seq ( seq1 seq2 -- seq )
#! { aceg } { bdfh } -> { abcdefgh }
[ zip concat ] keep like ;
: mod-nth ( n seq -- elt )
#! 5 "abcd" -> b
[ length mod ] [ nth ] bi ;