Ok, it looked like a nice little challenge.

Pass the udf a mask to generate a password. The mask may contain the numbers 1, 2 or 4 which correspond to the character class "alpha", "numeric" or "special character". You may add the numbers together, so 3 would mean "alpha or numeric", 7 would mean "any class" and so-on.

And other character will be included in the password as-is. If you need to include one of the numbers 1-7, prefix it with the "\" character.

No character will match the preceeding character.

Some examples:
  • funStrongRandom("112222") Two alpha followed by 4 numeric digits: GI8781
  • funStrongRandom("11-2222") As above, but the numeric and alpha parts are seperated by a hyphen: GI-8781
  • funStrongRandom("11-222\2") As above, but the final digit is a hard-coded '2': GI-8782
  • funStrongRandom("114333\\\2") As above, except the seperator is a random special character, the characters following the seperator may be numberic or alpha, and the final constant "2" is prefixed by a "\" character: GI^U2A\2

Break ON
 
SRnd(@MSECS)    ; You should use a better seed than this one
$=Rnd(1)        ; Discard low random
 
funStrongRandom("11-22733\1\2\3") ?
 
Function funStrongRandom($sPasswordMask)
        $asClasses="ABCDEFGHIJKLMNOPQRSTUVWXYZ","1234567890","!£$$%%^&*()-_=+[]{};:'@@#~,<.>/?\|"
        $funStrongRandom=""  ; Initialise as string
 
        While $sPasswordMask
                $iClass=CInt(Left($sPasswordMask,1))
                Select
                Case $iClass AND $iClass<8      ; Use a random character.
                        $sPossibles=IIF($iClass & 1,$asClasses[0],"")
                        $sPossibles=$sPossibles+IIF($iClass & 2,$asClasses[1],"")
                        $sPossibles=$sPossibles+IIF($iClass & 4,$asClasses[2],"")
                        Do
                                $sChar=SubStr($sPossibles,1+Rnd(Len($sPossibles)-1),1)
                        Until $sChar<>Right($funStrongRandom,1)
                        $funStrongRandom=$funStrongRandom+$sChar
                Case Left($sPasswordMask,1)='\' ; Use next character explicitly.
                        $funStrongRandom=$funStrongRandom+SubStr($sPasswordMask,2,1)
                        $sPasswordMask=SubStr($sPasswordMask,2)
                Case "True"                     ; Use this character explicitly.
                        $funStrongRandom=$funStrongRandom+Left($sPasswordMask,1)
                EndSelect
                $sPasswordMask=SubStr($sPasswordMask,2)
        Loop
EndFunction