'[RC]MD5
    'from tsh73's January 2008 code

    text$="The quick brown fox jumps over the lazy dog"
    checkSum$="9e107d9d372bb6826bd81d3542a419d6"

    print text$
    print checkSum$

    test$=md5$(text$)

    if test$=checkSum$ then
        print "passed"
        print test$
    else
        print "failed"
    end if
    end

    function md5$(text$)

        dim r(64)
        dim k(64)
        dim w(16)
        global two32
        two32=2^32

        'prepare the MD5 checksum table
        restore [perRoundShiftAmounts]
        for i=0 to 63
            read x
            r(i)=x
        next

        'prepare constants
        for i=0 to 63
            k(i) =  int(abs(sin(i+1)) * two32)
        next

        'initialise variables
        h0 = HEXDEC("67452301")
        h1 = HEXDEC("EFCDAB89")
        h2 = HEXDEC("98BADCFE")
        h3 = HEXDEC("10325476")

        'find num bits in message
        numbits=len(text$)*8

        'add bits "10000000"
        text$=text$+chr$(128)

        'add bits "00000000"
        while len(text$) mod 64 <> 56
            text$=text$+chr$(0)
        wend

        'add original length in bits
        text$=text$+dec2asc$(numbits)

        'MD5 rounds
        'process in 64 byte chunks 512bits
        for chunk = 1 to len(text$) step 64
            chunk$ = mid$(text$, chunk, 64)
            for word = 0 TO 15
                'invert byte order
                b0 = asc(mid$(chunk$, word*4+1, 1))
                b1 = asc(mid$(chunk$, word*4+2, 1))
                b2 = asc(mid$(chunk$, word*4+3, 1))
                b3 = asc(mid$(chunk$, word*4+4, 1))
                w(word) = ((b3*256+b2)*256+b1)*256+b0
            next word
            a = h0
            b = h1
            c = h2
            d = h3
            for i = 0 to 63
                select case
                    case 0 <= i and i <= 15
                        f = (b and c) or (bitNot(b) and d)
                        g = i
                    case 16 <= i and i <= 31
                        f = (d and b) or (bitNot(d) and c)
                        g = (5 * i + 1) mod 16
                    case 32 <= i and i <= 47
                        f = b xor c xor d
                        g = (3 * i + 5) mod 16
                    case 48 <= i and i <= 63
                        f = c xor (b or bitNot(d))
                        g = (7 * i) mod 16
                end select
                temp = d
                d = c
                c = b
                b=b+leftrotate(a + f + k(i) + w(g),r(i))
                b = b mod two32
                a = temp
            next i
            h0 = (h0 + a) mod two32
            h1 = (h1 + b) mod two32
            h2 = (h2 + c) mod two32
            h3 = (h3 + d) mod two32
        next chunk

        md5$ =  revOrd$(DECHEX$(h0))+_
                revOrd$(DECHEX$(h1))+_
                revOrd$(DECHEX$(h2))+_
                revOrd$(DECHEX$(h3))

        [perRoundShiftAmounts]
        DATA 7,12,17,22, 7,12,17,22, 7,12,17,22, 7,12,17,22
        DATA 5, 9,14,20, 5, 9,14,20, 5, 9,14,20, 5, 9,14,20
        DATA 4,11,16,23, 4,11,16,23, 4,11,16,23, 4,11,16,23
        DATA 6,10,15,21, 6,10,15,21, 6,10,15,21, 6,10,15,21

    end function


    ' dec2asc: dec to 8 byte asc
    function dec2asc$(n)
        h$ = ""
        for i = 1 to 8
            h$ = h$ + chr$(n mod 256)
            n = int(n/256)
        next
        dec2asc$= h$
    end function

    ' bitNot
    function bitNot(num)
        bitNot = two32 -1 -num
    end function

    ' leftrotate: spins bits left n times
    function leftrotate(num,times)
        num=num mod two32
        r = (num*2^times) mod two32
        l = int(num/(2^(32-times)))
        leftrotate = r+l
    end function

    ' reverse the HEXDEC$ order
    function revOrd$(a$)
        a$=left$("00000000", 8-len(a$))+a$
        revOrd$ = lower$(mid$(a$,7,2)+mid$(a$,5,2)+mid$(a$,3,2)+mid$(a$,1,2))
    end function