iterations = 32
delta = 0x9e3779b9
xTeaKey = [(an int32), (an int32), (an int32), (an int32)]

def int_overflow(val):
 if not -sys.maxint-1 <= val <= sys.maxint:
   val = (val + (sys.maxint + 1)) % (2 * (sys.maxint + 1)) - sys.maxint - 1

 if not -0xffffffff <= val <= 0xffffffff - 1:
   print "AAAAAH"

 return val

def xTeaShuffle(x, sum, sumOffset) :
 e1 = (x << 4) & 0xffffffff
 e2 = x >> 5
 e3 = e1 ^ e2
 e4 = int_overflow(e3 + x)

 e5a = int_overflow(sum + xTeaKey[(sum & 0x03)]);
 e5b = int_overflow(sum + xTeaKey[((sum >> 11) & 0x03)]);
 e5 = e5b if sumOffset else e5a

 result = e4 ^ e5

 return result

#data must be a short array and length must be divisible by 4
def xTeaEncode(data, length) :
 i = 0

 while i < length:
   sum = 0
   x1 = (data[i] << 16) + data[i + 1]
   x2 = (data[i + 2] << 16) + data[i + 3]

   iter = iterations

   while iter > 0 :
     x1 = int_overflow(x1 + xTeaShuffle(x2, sum, False))
     sum = int_overflow(sum + delta);
     x2 = int_overflow(x2 + xTeaShuffle(x1, sum, True))
     iter -= 1

   data[i] = (x1 >> 16)
   data[i + 1] = x1 & 0xffff
   data[i + 2] = (x1 >> 16)
   data[i + 3] = x2 & 0xffff

 i += 4

return

#data must be a short array and length must be divisible by 4
def xTeaDecode(data, length) :
 i = 0

 while i < length:
   sum = int_overflow(delta * iterations)
   x1 = (data[i] << 16) + data[i + 1]
   x2 = (data[i + 2] << 16) + data[i + 3]

   while (sum != 0) :

     x2 = int_overflow(x2 - xTeaShuffle(x1, sum, True))
     sum = int_overflow(sum - delta);
     x1 = int_overflow(x1 - xTeaShuffle(x2, sum, False))

   data[i] = (x1 >> 16)
   data[i + 1] = x1 & 0xffff
   data[i + 2] = (x1 >> 16)
   data[i + 3] = x2 & 0xffff

 i += 4

 return

DllExport void _stdcall XTEAEncode16(unsigned short *data, unsigned char dataLength) 
{
unsigned char i = 0;
int x1;
int x2;
int sum;
unsigned char iterationCount;

while (i < dataLength) 
{
sum = 0;
x1 = ((unsigned int)data[i] << 16) + (unsigned int)data[i+1];
x2 = ((unsigned int)data[i+2] << 16) + (unsigned int)data[i+3];
iterationCount = NUM_ITERATIONS;

while (iterationCount > 0) 
{
x1 += (((x2 << 4) ^ (x2 >> 5)) + x2) ^ (sum + XTEAKey[(sum & 0x03)]);
sum += DELTA;
x2 += (((x1 << 4) ^ (x1 >> 5)) + x1) ^ (sum + XTEAKey[((sum >> 11) & 0x03)]);
iterationCount--;
}
data[i]   = (unsigned short)((unsigned int)x1>>16); /* take upper half as an int*/
data[i+1] = (unsigned short)(unsigned int)x1; /* take lower half */
data[i+2] = (unsigned short)((unsigned int)x2>>16); /* take upper half as an int*/
data[i+3] = (unsigned short)(unsigned int)x2; /* take lower half */

i += 4;
}
}

/**
* Decodes (deciphers) data.
* Note that data length must be a multiple of 4 words (64 bit). 
*//* *< 16-bit data array *//* *< length of data array */
DllExport void _stdcall  XTEADecode16(unsigned short* data, unsigned char dataLength ) 
{
unsigned char i = 0;
int x1;
int x2;
int sum;
unsigned char iterations;

iterations = NUM_ITERATIONS;

while (i < dataLength) 
{
sum = DELTA * iterations;
x1 = ((unsigned int)data[i] << 16) + (unsigned int)data[i+1];
x2 = ((unsigned int)data[i+2] << 16) + (unsigned int)data[i+3];

while (sum != 0) 
{
x2 -= (((x1 << 4) ^ (x1 >> 5)) + x1) ^ (sum + XTEAKey[((sum >> 11) & 0x03)]);
sum -= DELTA;
x1 -= (((x2 << 4) ^ (x2 >> 5)) + x2) ^ (sum + XTEAKey[(sum & 0x03)]);
}
data[i]   = (unsigned short)((unsigned int)x1 >> 16); /* take upper half as an int*/
data[i+1] = (unsigned short)((unsigned int)x1); /* take lower half */
data[i+2] = (unsigned short)((unsigned int)x2 >> 16); /* take upper half as an int*/
data[i+3] = (unsigned short)((unsigned int)x2); /* take lower half */

i += 4;
}
}