passwd-md5 ( magic salt password -- bytes )
MD5 shadow passwords

Next:

parse-shadow-password ( string -- magic salt password )

Vocabulary
crypto.passwd-md5

Inputs

magic	a string
salt	a string
password	a string

Outputs

bytes

an md5-shadowed password entry

Word description
Encodes the password with the given magic string and salt to an MD5-shadow password entry.

Definition

USING: checksums checksums.md5 combinators
crypto.passwd-md5.private grouping kernel math math.bits
math.functions sequences ;

IN: crypto.passwd-md5

:: passwd-md5 ( magic salt password -- bytes )
    password magic salt 3append salt password 1surround
    md5 checksum-bytes password length
    [ 16 / ceiling swap <repetition> concat ] keep head-slice
    append password [ length make-bits ] [ first ] bi
    [ [ 0 ] ] dip [ ? ] curry compose "" map-as append
    md5 checksum-bytes :> final! 1000 <iota> [
        "" swap {
            [ 0 bit? password final ? append ]
            [ 3 mod 0 > [ salt append ] when ]
            [ 7 mod 0 > [ password append ] when ]
            [ 0 bit? final password ? append ]
        } cleave md5 checksum-bytes final!
    ] each magic salt "$" 3append
    { 12 0 6 13 1 7 14 2 8 15 3 9 5 4 10 } final nths 3 group
    [ first3 [ 16 shift ] [ 8 shift ] bi* + + 4 to64 ] map
    concat 11 final nth 2 to64 3append ;