Script Library: 1213 scripts
 

arcfour.r

REBOL [ Title: "ARCFOUR and CipherSaber" Date: 17-Jan-2004 File: %arcfour.r Author: "Cal Dixon" Purpose: {Provides encryption and decryption using the ARCFOUR algorithm} Note: {this implementation can decrypt data at about 40KB/s on my 1Ghz AMD Duron system with Rebol/View 1.2.10.3.1} Library: [ level: 'advanced platform: 'all type: [function module protocol] domain: [encryption scheme] tested-under: [view 1.2.10.3.1 on [W2K] by "Cal"] license: 'PD support: none ] ] ;ARCFOUR specification: http://www.mozilla.org/projects/security/pki/nss/draft-kaukonen-cipher-arcfour-03.txt ;CipherSabre specification: http://ciphersaber.gurus.com/faq.html#getrc4 arcfour-short: func [key [string! binary!] stream [binary! string!] /mix n /local state i j output swap addmod sz][ swap: func [a b s /local][ local: sz s a poke s a + 1 to-char sz s b poke s b + 1 to-char local ] addmod: func [ a b ][ a + b // 256 ] sz: func [ s a ][ pick s a + 1 ] state: make binary! 256 repeat var 256 [ insert tail state to-char var - 1 ] j: 0 loop any [ n 1 ] [ i: 0 loop 256 [ swap i j: addmod j add sz state i sz key i // length? key state i: i + 1] ] i: j: 0 output: make binary! length? stream repeat byte stream [ swap i: addmod i 1 j: addmod j sz state i state insert tail output to-char xor~ byte to-char sz state addmod (sz state i) (sz state j) ] clear state return output ] make root-protocol [ addmod: addmod: func [ a b ][ a + b // 256 ] sz: func [ s a ][ pick s a + 1 ] swap: func [a b s /local][ local: sz s a poke s a + 1 to-char sz s b poke s b + 1 to-char local ] ins: get in system/words 'insert i: 0 j: 0 open: func [port][ port/state/tail: 2000 port/state/index: 0 port/state/flags: port/state/flags or port-flags port/locals: context [ inbuffer: make binary! 40000 state: make binary! 256] use [key n i j] [ key: port/key n: port/strength repeat var 256 [ ins tail port/locals/state to-char var - 1 ] j: 0 loop any [ n 1 ] [ i: 0 loop 256 [ swap i j: addmod j add sz port/locals/state i sz key i // length? key port/locals/state i: i + 1 ] ] ] i: j: 0 ] insert: func [port data][ system/words/insert tail port/locals/inbuffer data do [] ] copy: func [port /local output][ output: make binary! local: length? port/locals/inbuffer loop local [ swap i: addmod i 1 j: addmod j sz port/locals/state i port/locals/state ins tail output to-char sz port/locals/state addmod (sz port/locals/state i) (sz port/locals/state j) ] local: xor~ output port/locals/inbuffer clear port/locals/inbuffer local ] close: func [port][ clear port/locals/inbuffer clear port/locals/state clear port/url clear port/key] port-flags: system/standard/port-flags/pass-thru net-utils/net-install arcfour self 0 ] arcfour: func [key stream /mix n /local port][ port: open compose [scheme: 'arcfour key: (key) strength: (n)] insert port stream local: copy port close port return local ] ; CipherSaber is an ARCFOUR stream prepended with 10 bytes of random key data ciphersaber: func [ key stream /v2 n ][ arcfour/mix join key copy/part stream 10 skip stream 10 either v2 [ any [ n 42 ] ][ 1 ] ] comment [ ; Tests probe to-string ciphersaber "asdfg" #{6F6D0BABF3AA6719031530EDB677CA74E0089DD0e7b8854356bb1448e37cdbefe7f3a84f4f5fb3fd} #{7494C2E7104B0879} = arcfour to-string #{0123456789ABCDEF} #{0000000000000000} #{f13829c9de} = arcfour to-string #{618a63d2fb} #{dcee4cf92c} probe to-string ciphersaber/v2 "asdfg" #{ba9ab4cffb7700e618e382e8fcc5ab9813b1abc436ba7d5cdea1a31fb72fb5763c44cfc2ac77afee19ad} 10 i: load ciphersaber "ThomasJefferson" read/binary http://ciphersaber.gurus.com/cknight.cs1 view layout [image i] ]
halt ;; to terminate script if DO'ne from webpage