factor/extra/base32/base32.factor

78 lines
2.1 KiB
Factor

! Copyright (C) 2019 John Benediktsson
! See http://factorcode.org/license.txt for BSD license
USING: base64.private byte-arrays combinators fry io io.binary
io.encodings.binary io.streams.byte-array kernel kernel.private
literals math namespaces sequences ;
IN: base32
ERROR: malformed-base32 ;
! XXX: Optional map 0 as O
! XXX: Optional map 1 as L or I
! XXX: Optional handle lower-case input
<PRIVATE
<<
CONSTANT: alphabet $[ "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567" >byte-array ]
>>
: ch>base32 ( ch -- ch )
alphabet nth ; inline
: base32>ch ( ch -- ch )
$[ alphabet alphabet-inverse 0 CHAR: = pick set-nth ] nth
[ malformed-base32 ] unless* { fixnum } declare ; inline
: encode5 ( seq -- byte-array )
be> { -35 -30 -25 -20 -15 -10 -5 0 } '[
shift 0x1f bitand ch>base32
] with B{ } map-as ; inline
: encode-pad ( seq n -- byte-array )
[ 5 0 pad-tail encode5 ] [ B{ 0 2 4 5 7 } nth ] bi* head-slice
8 CHAR: = pad-tail ; inline
: (encode-base32) ( stream column -- )
5 pick stream-read dup length {
{ 0 [ 3drop ] }
{ 5 [ encode5 write-lines (encode-base32) ] }
[ encode-pad write-lines (encode-base32) ]
} case ;
PRIVATE>
: encode-base32 ( -- )
input-stream get f (encode-base32) ;
: encode-base32-lines ( -- )
input-stream get 0 (encode-base32) ;
<PRIVATE
: decode8 ( seq -- )
[ 0 [ base32>ch swap 5 shift bitor ] reduce 5 >be ]
[ [ CHAR: = = ] count ] bi
[ write ] [ B{ 0 4 0 3 2 0 1 } nth head-slice write ] if-zero ; inline
: (decode-base32) ( stream -- )
8 "\n\r" pick read-ignoring dup length {
{ 0 [ 2drop ] }
{ 8 [ decode8 (decode-base32) ] }
[ drop 8 CHAR: = pad-tail decode8 (decode-base32) ]
} case ;
PRIVATE>
: decode-base32 ( -- )
input-stream get (decode-base32) ;
: >base32 ( seq -- base32 )
binary [ binary [ encode-base32 ] with-byte-reader ] with-byte-writer ;
: base32> ( base32 -- seq )
binary [ binary [ decode-base32 ] with-byte-reader ] with-byte-writer ;
: >base32-lines ( seq -- base32 )
binary [ binary [ encode-base32-lines ] with-byte-reader ] with-byte-writer ;