MD4

From Second Life Wiki
Jump to: navigation, search
Emblem-important-red.png Security Warning!

The MD4 hashing algorithm should not be used because it is too easy to generate collisions (two inputs which result in the same hash).

Preforms a MD4 Hash on the text. Similar to the MD5 hash. MD4 should not be used. This code is provided for the sake of completeness. Two versions of the function are provided, one for UTF-8 Strings (all strings in LSL are UTF-8) and the other is for Base64 Strings (you need to tell it how many bits long the data is).

There is also an SHA-1 & two SHA-2 implementations (224 & 256).

View http://en.wikipedia.org/wiki/MD4 for more information.

//////////////////////////////////////////////////////////////////////////////////////
//
//	UTF-8 MD4
//	Version 1.1 Beta
//	ESL Compiled: "Dec 13 2010", "01:20:46"
//	Copyright (C) 2010  Strife Onizuka
//	Based on code RFC 1320
//	
//
//	This library is free software; you can redistribute it and/or
//	modify it under the terms of the GNU Lesser General Public License
//	as published by the Free Software Foundation;
//	version 3 of the License.
//	
//	This library is distributed in the hope that it will be useful,
//	but WITHOUT ANY WARRANTY; without even the implied warranty of
//	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//	GNU Lesser General Public License for more details.
//	
//	You should have received a copy of the GNU Lesser General Public License
//	along with this library.  If not, see <http://www.gnu.org/licenses/>
//	or write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
//	Boston, MA  02111-1307  USA
//	
//////////////////////////////////////////////////////////////////////////////////////
 
//===================================================//
//                 Combined Library                  //
//             "Dec 13 2010", "01:20:46"             //
//  Copyright (C) 2004-2008, Strife Onizuka (cc-by)  //
//    http://creativecommons.org/licenses/by/3.0/    //
//===================================================//
//{
 
string TrimRight(string src, string chrs)//LSLEditor Safe, LSO Safe
{
    integer i = llStringLength(src);
    integer j = i;
    do ; while(~llSubStringIndex(chrs, llGetSubString(src, i = ~-(j = i), i)) && j);
    return llDeleteSubString(src, j, 0x7FFFFFF0);
}
 
string hexc="0123456789ABCDEF";
 
//} Combined Library
 
list r1 = [3,  7, 11, 19];
list r2 = [3,  5,  9, 13];
list r3 = [3,  9, 11, 15];
 
list i3 = [0,  8,  4, 12,    2, 10,  6, 14,       1,  9,  5, 13,    3, 11,  7, 15];
 
string UTF8_MD4(string plain) { 
    integer H1 = 1732584193;
    integer H2 = -271733879;
    integer H3 = -1732584194;
    integer H4 = 271733878;
 
    //OR on the extra bit.
    integer j = llStringLength(plain = llStringToBase64(plain));
    integer T = 0x80000000;
    if (j) {
        do ; while (llGetSubString(plain, (j = ~-j), j) == "=");
        j = (-6 * ~j) & -8;
        T = llBase64ToInteger((llGetSubString(plain, -4, j / 6)) + "AAAAAA") | (0x00000080 << ((j % 3) << 3));
    }
    integer b = ((j + 40) >> 5) | 15;
    string buf = "AAA";
    integer i = -5;
    do buf += buf; while((i = -~i));
//    llOwnerSay(llList2CSV([i,j]));
    plain = llGetSubString( llDeleteSubString(plain, -4, -1) + 
                            llGetSubString(llIntegerToBase64(T), 0, 5) + 
                            buf, 0, ((b << 4) / 3) - 7) + 
            llGetSubString(llIntegerToBase64((((j & 0xFF) << 20) | ((j & 0xFF00) << 4) | ((j >> 12) & 0xFF0) | ((j >> 28) & 0xF)) >> ((b % 3) << 1)), 0, 5) + 
            "AAAAAAAA";
    integer S = i = 0;
    list x;
    do
    {
        integer A = H1;
        integer B = H2;
        integer C = H3;
        integer D = H4;
 
        j = 0;
        x = [];
        do
        {
            T = llBase64ToInteger(buf = llGetSubString(plain, T = ((i + j) << 4) / 3, T+6)) << (S = (((i + j) % 3) << 1));
            if(S)
                T = T | (llBase64ToInteger("A" + (llDeleteSubString(buf, 0, 1))) >> (6 - S));
            x += (T = ((T << 24) | ((T & 0xFF00) << 8) | ((T >> 8) & 0xFF00) | ((T >> 24) & 0xFF)));
 
            S = A + (D ^ (B & (C ^ D))) + T;
            T = llList2Integer(r1, j & 3);
            A = D;
            D = C;
            C = B;
            B = (S << T) | ((S >> (32 - T)) & ~(-1 << T));
        }
        while(16 > (j = -~j));
        do
        {
            S = A + ((B & C) | (B & D) | (C & D)) + llList2Integer(x, (-~(((j << 2) - 65) % 15))) + 1518500249;
            T = llList2Integer(r2, j & 3);
            A = D;
            D = C;
            C = B;
            B = (S << T) | ((S >> (32 - T)) & ~(-1 << T));
        }
        while(32 > (j = -~j));
        do
        {
            S = A + (B ^ C ^ D) + llList2Integer(x, llList2Integer(i3, j & 15)) + 1859775393;
            T = llList2Integer(r3, j & 3);
            A = D;
            D = C;
            C = B;
            B = (S << T) | ((S >> (32 - T)) & ~(-1 << T));
        }
        while(48 > (j = -~j));
//        llOwnerSay(llList2CSV(x));
        H1 += A;
        H2 += B;
        H3 += C;
        H4 += D;
    }while(b > (i += 16));
    x = [H4, H3, H2, H1];
    i = -4;
    buf = "";
    do
    {
        T = llList2Integer(x,i);
        j = 32;
        do
            buf = llGetSubString(hexc, b = ((T >> (j - 4)) & 0xF), b) + llGetSubString(hexc, b = ((T >> (j - 8)) & 0xF), b) + buf;
        while ((j -= 8));
    }while ((i = -~i));
    return buf;
}
 
string Base64_MD4(string plain, integer bit_length) { //$[E20009]
    integer H1 = 1732584193;
    integer H2 = -271733879;
    integer H3 = -1732584194;
    integer H4 = 271733878;
 
    //OR on the extra bit.
    integer b = (~-(((bit_length + 552) & -512) >> 5));
    integer T = llBase64ToInteger((TrimRight(llGetSubString(plain = llStringToBase64(plain), -4, -1),"=")) + "AAAA");
    string buf = "AAA";
    integer i = -5;
    do buf += buf; while((i = -~i));
    if(bit_length)
    {
        i = 0x800000;
        if(T & 0xFF00)
            i = 0x00000080;
        else if(T & 0xFF0000)
            i = 0x00008000;
    }
    else
        T = 0x80000000;//T is corrupt because of https://jira.secondlife.com/browse/SVC-104
//    llOwnerSay(llList2CSV([i,bit_length]));
    plain = llGetSubString( llDeleteSubString(plain, -4, -1) + 
                            llGetSubString(llIntegerToBase64(T | i), 0, 5) + 
                            buf, 0, ((b << 4) / 3) - 7) + 
            llGetSubString(llIntegerToBase64((((bit_length & 0xFF) << 20) | ((bit_length & 0xFF00) << 4) | ((bit_length >> 12) & 0xFF0) | ((bit_length >> 28) & 0xF)) >> ((b % 3) << 1)), 0, 5) + 
            "AAAAAAAA";
    integer S = i = 0;
    list x;
    do
    {
        integer A = H1;
        integer B = H2;
        integer C = H3;
        integer D = H4;
 
        bit_length = 0;
        x = [];
        do
        {
            T = llBase64ToInteger(buf = llGetSubString(plain, T = ((i + bit_length) << 4) / 3, T+6)) << (S = (((i + bit_length) % 3) << 1));
            if(S)
                T = T | (llBase64ToInteger("A" + (llDeleteSubString(buf, 0, 1))) >> (6 - S));
            x += (T = ((T << 24) | ((T & 0xFF00) << 8) | ((T >> 8) & 0xFF00) | ((T >> 24) & 0xFF)));
 
            S = A + (D ^ (B & (C ^ D))) + T;
            T = llList2Integer(r1, bit_length & 3);
            A = D;
            D = C;
            C = B;
            B = (S << T) | ((S >> (32 - T)) & ~(-1 << T));
        }
        while(16 > (bit_length = -~bit_length));
        do
        {
            S = A + ((B & C) | (B & D) | (C & D)) + llList2Integer(x, (-~(((bit_length << 2) - 65) % 15))) + 1518500249;
            T = llList2Integer(r2, bit_length & 3);
            A = D;
            D = C;
            C = B;
            B = (S << T) | ((S >> (32 - T)) & ~(-1 << T));
        }
        while(32 > (bit_length = -~bit_length));
        do
        {
            S = A + (B ^ C ^ D) + llList2Integer(x, llList2Integer(i3, bit_length & 15)) + 1859775393;
            T = llList2Integer(r3, bit_length & 3);
            A = D;
            D = C;
            C = B;
            B = (S << T) | ((S >> (32 - T)) & ~(-1 << T));
        }
        while(48 > (bit_length = -~bit_length));
//        llOwnerSay(llList2CSV(x));
        H1 += A;
        H2 += B;
        H3 += C;
        H4 += D;
    }while(b > (i += 16));
    x = [H4, H3, H2, H1];
    i = -4;
    buf = "";
    do
    {
        T = llList2Integer(x,i);
        bit_length = 32;
        do
            buf = llGetSubString(hexc, b = ((T >> (bit_length - 4)) & 0xF), b) + llGetSubString(hexc, b = ((T >> (bit_length - 8)) & 0xF), b) + buf;
        while ((bit_length -= 8));
    }while ((i = -~i));
    return buf;
}
 
integer go(string in, string answer)
{
    llOwnerSay("");
    llResetTime();
    string out = UTF8_MD4(in);
    float t = llGetTime();
    llOwnerSay(llDumpList2String(([out,t,llStringLength(in)]),","));
    if(answer)
    {
        llOwnerSay(answer);
        return answer == out;
    }
    return TRUE;
}
 
default
{
 
    state_entry()
    {
        llListen(0, "", "", "");
        if(go("","31D6CFE0D16AE931B73C59D7E0C089C0"))
            if(go("abc","A448017AAF21D8525FC10AE87AA6729D"))
                go("The quick brown fox jumps over the lazy dog","1BEE69A46BA811185C194762ABAEAE90");
//        llOwnerSay((string)llGetTime());
    }
    listen(integer a, string b, key c, string d)
    {
        llOwnerSay(UTF8_MD4(d));
    }
}