De DigiWiki.
// This script includes the XTEA-LSL-Implementation by:
// - Morse Dillon
// - Strife Onizuka
// - Dedric Mauriac
// - JB Kraft
// http://wiki.secondlife.com/wiki/XTEA_Strong_Encryption_Implementation
// Setup:
// 1. Make sure the object in which you want to use this script has more than one prim.
// 2. Make sure the object is modifiable by you.
// 3. This script must go into a childprim of your object, it doesn't matter into which one.
// 4. After you have copied the script into your object, make sure everyone you want to talk to has the same
// settings for KEY1, KEY2, KEY3, KEY4 and COMM_CHANNEL. You can use any valid, positive (!) integer number
// for COMM_CHANNEL excluding PUBLIC_CHANNEL (which is 0) and DEBUG_CHANNEL (which is 2147483647). Do not use
// a negative channel!
// 5. When chatting, please type in local chat and add your channel. Example: If your COMM_CHANNEL was 9 then you'd type: '/9 hello'
// 6. The code is written for an avatar attachment (usually a headset / HUD) and will run in no-script areas.
integer COMM_CHANNEL = 9;
integer KEY1 = 11111111;
integer KEY2 = 22222222;
integer KEY3 = 33333333;
integer KEY4 = 44444444;
// If you're not sure what you're doing,
// do NOT change anything below!
key ownerKey;
string ownerName;
integer CYCLES = 6;
list cypherkey;
integer delta = 0x9E3779B9;
integer ord(string chr)
{
if (llStringLength(chr) != 1)
{
return ERR_GENERIC;
}
if (chr == " ")
{
return 32;
}
string ASCII = " \n !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";
return llSubStringIndex(ASCII, chr);
}
string chr(integer i)
{
i %= 127;
string ASCII = " \n !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";
return llGetSubString(ASCII, i, i);
}
string DWord2Hex(integer m)
{
string result;
integer index;
string characters = "0123456789ABCDEF";
integer i;
for (; i < 8; i++)
{
index = (m >> (i * 4)) & 0xF;
result = llInsertString(result, 0, llGetSubString(characters, index, index));
}
return result;
}
integer Hex2DWord(string m)
{
integer result;
string digit;
integer value;
integer index;
string characters = "0123456789ABCDEF";
integer i;
for (; i < 8; i++)
{
index = 8 - (i + 1);
digit = llGetSubString(m,index,index);
value = llSubStringIndex(characters, digit);
result = result | value << (i * 4);
}
return result;
}
string Encrypt(string cleartext)
{
integer cyphertext_numeric;
integer dword1;
integer dword2;
list cypherblock;
string cyphertext;
while(llStringLength(cleartext) & 0x7)
{
cleartext += " ";
}
integer character;
integer stringlength = llStringLength(cleartext);
integer i;
while (i < stringlength)
{
dword1 = ord(llGetSubString(cleartext,i,i));
i++;
dword1 = dword1 | (ord(llGetSubString(cleartext,i,i)) << 8);
i++;
dword1 = dword1 | (ord(llGetSubString(cleartext,i,i)) << 16);
i++;
dword1 = dword1 | (ord(llGetSubString(cleartext,i,i)) << 24);
i++;
dword2 = ord(llGetSubString(cleartext,i,i));
i++;
dword2 = dword2 | ord(llGetSubString(cleartext,i,i)) << 8;
i++;
dword2 = dword2 | ord(llGetSubString(cleartext,i,i)) << 16;
i++;
dword2 = dword2 | ord(llGetSubString(cleartext,i,i)) << 24;
i++;
cypherblock = TEAEncrypt(dword1,dword2,cypherkey);
cyphertext = cyphertext + DWord2Hex(llList2Integer(cypherblock,0)) + DWord2Hex(llList2Integer(cypherblock,1));
dword1 = 0;
dword2 = 0;
cypherblock = [];
}
return cyphertext;
}
string Decrypt(string cyphertext)
{
integer dword1;
integer dword2;
list clearblock;
string cleartext;
string hexvalue1;
string hexvalue2;
integer i;
while (i < llStringLength(cyphertext))
{
hexvalue1 += llGetSubString(cyphertext,i,i + 7);
i = i + 8;
hexvalue2 += llGetSubString(cyphertext,i,i + 7);
i = i + 8;
dword1 = Hex2DWord(hexvalue1);
dword2 = Hex2DWord(hexvalue2);
clearblock = TEADecrypt(dword1, dword2, cypherkey);
cleartext += chr( llList2Integer(clearblock, 0) & 0x000000FF);
cleartext += chr( (llList2Integer(clearblock, 0) & 0x0000FF00) >> 8);
cleartext += chr( (llList2Integer(clearblock, 0) & 0x00FF0000) >> 16);
cleartext += chr( (llList2Integer(clearblock, 0) & 0xFF000000) >> 24);
cleartext += chr( llList2Integer(clearblock, 1) & 0x000000FF);
cleartext += chr( (llList2Integer(clearblock, 1) & 0x0000FF00) >> 8);
cleartext += chr( (llList2Integer(clearblock, 1) & 0x00FF0000) >> 16);
cleartext += chr( (llList2Integer(clearblock, 1) & 0xFF000000) >> 24);
hexvalue1 = "";
hexvalue2 = "";
dword1 = 0;
dword2 = 0;
clearblock = [];
}
return cleartext;
}
list TEAEncrypt(integer dword1, integer dword2,list cypherkey)
{
integer sum;
list cryptlist;
integer n = CYCLES;
while (n-- > 0)
{
dword1 = dword1 + ( ( dword2 << 4 ^ ((dword2 >> 5) & 0x07FFFFFF) ) + dword2 ^ sum + llList2Integer(cypherkey, (sum & 3) ) );
sum += delta;
dword2 = dword2 + ( ( dword1 << 4 ^ ((dword1 >> 5) & 0x07FFFFFF) ) + dword1 ^ sum + llList2Integer(cypherkey, ((sum >> 11) & 3) ) );
}
cryptlist = [dword1,dword2];
return cryptlist;
}
list TEADecrypt(integer dword1, integer dword2,list cypherkey)
{
integer sum = delta * CYCLES;
list cryptlist;
integer n = CYCLES;
while (n-- > 0)
{
dword2 = dword2 - ( ( dword1 << 4 ^ ((dword1 >> 5) & 0x07FFFFFF) ) + dword1 ^ sum + llList2Integer(cypherkey, ((sum >> 11) & 3) ) );
sum -= delta;
dword1 = dword1 - ( ( dword2 << 4 ^ ((dword2 >> 5) & 0x07FFFFFF) ) + dword2 ^ sum + llList2Integer(cypherkey, (sum & 3) ) );
}
cryptlist = [dword1,dword2];
return cryptlist;
}
default
{
on_rez(integer start_param)
{
if (llGetOwner() != ownerKey)
{
llReleaseControls();
llResetScript();
}
}
changed(integer change)
{
if (change & CHANGED_OWNER)
{
llReleaseControls();
llResetScript();
}
}
state_entry()
{
ownerKey = llGetOwner();
ownerName = llKey2Name(ownerKey);
cypherkey = [KEY1, KEY2, KEY3, KEY4];
string timeStamp = llGetTimestamp();
llSetLinkPrimitiveParamsFast(LINK_THIS, [
PRIM_NAME, ownerName,
PRIM_DESC, timeStamp]);
llRequestPermissions(ownerKey, PERMISSION_TAKE_CONTROLS);
llListen(COMM_CHANNEL, "", NULL_KEY, "");
}
listen(integer channel, string name, key id, string message)
{
if (channel != COMM_CHANNEL)
{
return;
}
if (id == ownerKey)
{
llRegionSay(COMM_CHANNEL, Encrypt(message));
llSetLinkPrimitiveParamsFast(LINK_THIS, [PRIM_NAME, ""]);
llOwnerSay("/me [" + ownerName + "]: '" + message + "'");
llSetLinkPrimitiveParamsFast(LINK_THIS, [PRIM_NAME, ownerName]);
}
else if (llGetAgentSize(id) == ZERO_VECTOR)
{
message = Decrypt(message);
llSetLinkPrimitiveParamsFast(LINK_THIS, [PRIM_NAME, ""]);
llOwnerSay("/me [" + name + "]: '" + message + "'");
llSetLinkPrimitiveParamsFast(LINK_THIS, [PRIM_NAME, ownerName]);
}
}
run_time_permissions(integer perm)
{
if (perm & PERMISSION_TAKE_CONTROLS)
{
llTakeControls(CONTROL_DOWN, TRUE, TRUE);
}
}
// needs a control event for no-script-area hack
control(key id, integer level, integer edge)
{
;
}
}
