CS substitution cypher (simple)

DEFD = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890,./<>?;'[]\:^"{}|`~!@#$%^^&*()_+-= ^t^n" // "
DICT = "96p>.X#^t4/7A0^^5+,sHV<aLFT$E\D[3=]&KvtIzbm)?2q'MrUxQ1R%oecPn^ndyj{~^" }|ON-`;_GZk@CY!JhB*8S(lfuig:wW" // "

genrnddict = [
    local tmp dict
    dict = $DEFD
    loop c (strlen $dict) [
        c = (substr $dict (rnd (strlen $dict)) 1)
        dict = (strreplace $dict $c "")
        tmp = (concatword $tmp $c)
    ]
    result $tmp
]


encrypt = [
    arg2 = $DICT
    loopconcatword c (strlen $arg1) [ substr $arg2 (strstr $DEFD (substr $arg1 $c 1)) 1 ]
]

decrypt = [
    arg2 = $DICT
    loopconcatword c (strlen $arg1) [ substr $DEFD (strstr $arg2 (substr $arg1 $c 1)) 1 ]
]


testcrypto = [
    local output input
    input = (? $numargs $arg1 $DEFD)
    echo (concatword "^f8>>^f7" (escape $input))
    output = (encrypt $input)
    echo (concatword "^f8:::::^f4" (escape $output))
    output = (decrypt $output)
    echo (concatword "^f8<<" (? (=s $input $output) "^f9" "^f3") (escape $output))
]

// Use the commands below for more sophisticated encryption


encrypt = [
    local offset char out len1 len2 rndp n0 n1 n2 n3 n4 n5 n6 n7 n8 n9
    arg2 = $DICT
    loop i 10 [ [n@i] = (strstr $arg2 $i) ]
    len2 = (strlen $arg2)
    rndp = (& (rnd (pow (+ $n3 (* $n6 $n0)) (max 1 $n9))) 0xFF)
    arg1 = (concatword $arg1 (
        loopconcatword p $rndp [ result " " ]
    ) (tohex $rndp 2))
    len1 = (strlen $arg1)

    out = (loopconcatword c $len1 [
        char = (substr $arg1 $c 1)
        offset = (mod (- (+ $offset (* $len1 $n0) (div (* $n1 $n2) $c)) (* $n5 $n6) (div $n7 $n8 $n9)) $len2)
        substr $arg2 ( mod (
            + (strstr $DEFD $char) $offset
        ) $len2 ) 1
    ])
    result $out
]

decrypt = [
    local offset char out len1 len2 n0 n1 n2 n3 n4 n5 n6 n7 n8 n9
    arg2 = $DICT
    len1 = (strlen $arg1)
    len2 = (strlen $arg2)
    loop i 10 [ [n@i] = (strstr $arg2 $i) ]

    out = (loopconcatword c $len1 [
        char = (substr $arg1 $c 1)
        offset = (mod (- (+ $offset (* $len1 $n0) (div (* $n1 $n2) $c)) (* $n5 $n6) (div $n7 $n8 $n9)) $len2)
        substr $DEFD ( mod (
            + (- (strstr $arg2 $char) $offset) $len2
        ) $len2 ) 1
    ])
    substr $out 0 (- (strlen $out) (
        substr $out (- (strlen $out) 4) 4
    ) 4)
]