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md2

Wikipedia:

Message Digest Algorithm 2 (MD2) is a cryptographic hash function developed by Ronald Rivest in 1989. The algorithm is optimized for 8-bit computers. MD2 is specified in RFC 1319. Although other algorithms have been proposed since, such as MD4, MD5 and SHA, even as of 2004 MD2 remains in use in public key infrastructures as part of certificates generated with MD2 and RSA. The 128-bit (16-byte) MD2 hashes (also termed message digests) are typically represented as 32-digit hexadecimal numbers. Even a small change in the message will (with overwhelming probability) result in a completely different hash:

MD2("The quick brown fox jumps over the lazy dog") = 03d85a0d629d2c442e987525319fc471

MD2("The quick brown fox jumps over the lazy cog") = 6b890c9292668cdbbfda00a4ebf31f05

NOTE: This script requires initialization to use. To ready the script for use it must first be called without any arguments. This only needs to be done once.

md2(str)
Returns an MD2 hash (RFC 1319) computed from a given string.
COPY/// md2(str)
//
//  Returns an MD2 hash (RFC 1319) computed from a given string.
//
//  This script requires initialization to use. To ready the 
//  script for use it must first be called without any arguments. 
//  This only needs to be done once.
//
//      str     data to hash with MD2, string
//
//  Note:
//      This creates a lookup table in the form of a 256-entry
//      global array called _MD2tab[].
//
/// GMLscripts.com/license
{
    if (argument_count == 0) {
        // Initialize lookup table.
        var tab;
        tab  = "041046067201162216124001061054084161236240006019";
        tab += "098167005243192199115140152147043217188076130202";
        tab += "030155087060253212224022103066111024138023229018";
        tab += "190078196214218158222073160251245142187047238122";
        tab += "169104121145021178007063148194016137011034095033";
        tab += "128127093154090144050039053062204231191247151003";
        tab += "255025048179072165181209215094146042172086170198";
        tab += "079184056210150164125182118252107226156116004241";
        tab += "069157112089100113135032134091207101230045168002";
        tab += "027096037173174176185246028070097105052064126015";
        tab += "085071163035221081175058195092249206186197234038";
        tab += "044083013110133040132009211223205244065129077082";
        tab += "106220055200108193171250036225123008012189177074";
        tab += "120136149139227099232109233203213254059000029057";
        tab += "242239183014102088208228166119114248235117075010";
        tab += "049068080180143237031026219153141051159017131020";
        for (var i=0; i<256; i++) {
            global._MD2tab[i] = real(string_copy(tab, i*3+1, 3));
        }
        return 0;
    }

    var str,char,digest,i,j,k,L,M,N,X,pad;
    str = argument[0];
    N = string_length(str);
    pad = 16 - (N mod 16);
    str += string_repeat(chr(pad), pad);
    N = N + pad;
    for (i=0; i<N; i++) M[i]=ord(string_char_at(str,i+1));
    for (i=0; i<=15; i++) C[i] = 0;
    L = 0;
    for (i=0; i<(N div 16); i++) {
        for(j=0; j<=15; j++) {
            char = M[i*16+j];
            C[j] = C[j] ^ global._MD2tab[char ^ L];
            L = C[j];
        }
    }
    for (i=0; i<=15; i++) M[i+N] = C[i];
    N += 16;
    for (i=0; i<48; i++) X[i] = 0;
    for (i=0; i<(N div 16); i++) {
        for (j=0; j<=15; j++) {
            X[16+j] = M[i*16+j];
            X[32+j] = (X[16+j] ^ X[j]);
        }
        t = 0;
        for (j=0; j<18; j++) {
            for (k=0; k<48; k++) {
                t = X[k] ^ global._MD2tab[t];
                X[k] = t;
            }
            t = (t+j) mod 256;
        }
    }
    digest = "";
    for (i=0; i<=15; i++) {
        digest += string_char_at("0123456789abcdef", X[i] div 16 + 1);
        digest += string_char_at("0123456789abcdef", X[i] mod 16 + 1);
    }
    return digest;
}

Contributors: xot

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