import operator
 
print "First bits (for 'aaaa'): 01100001 01100001 01100001 01100001", "\n"
# STEP 1
print "STEP 1", "\n", "------"
print """Appended to 16 bytes:
01100001011000010110000101100001000011000000110000001100000011000000110000001100000011000000110000001100000011000000110000001100""", "\n"
 
# STEP 2
print "STEP 2", "\n", "------"
S = [
  41,  46,  67, 201, 162, 216, 124,   1,  61,  54,  84, 161, 236, 240,   6,  19,
  98, 167,   5, 243, 192, 199, 115, 140, 152, 147,  43, 217, 188,  76, 130, 202,
  30, 155,  87,  60, 253, 212, 224,  22, 103,  66, 111,  24, 138,  23, 229,  18,
 190,  78, 196, 214, 218, 158, 222,  73, 160, 251, 245, 142, 187,  47, 238, 122,
 169, 104, 121, 145,  21, 178,   7,  63, 148, 194,  16, 137,  11,  34,  95,  33,
 128, 127,  93, 154,  90, 144,  50,  39,  53,  62, 204, 231, 191, 247, 151,   3,
 255,  25,  48, 179,  72, 165, 181, 209, 215,  94, 146,  42, 172,  86, 170, 198,
  79, 184,  56, 210, 150, 164, 125, 182, 118, 252, 107, 226, 156, 116,   4, 241,
  69, 157, 112,  89, 100, 113, 135,  32, 134,  91, 207, 101, 230,  45, 168,   2,
  27,  96,  37, 173, 174, 176, 185, 246,  28,  70,  97, 105,  52,  64, 126,  15,
  85,  71, 163,  35, 221,  81, 175,  58, 195,  92, 249, 206, 186, 197, 234,  38,
  44,  83,  13, 110, 133,  40, 132,   9, 211, 223, 205, 244,  65, 129,  77,  82,
 106, 220,  55, 200, 108, 193, 171, 250,  36, 225, 123,   8,  12, 189, 177,  74,
 120, 136, 149, 139, 227,  99, 232, 109, 233, 203, 213, 254,  59,   0,  29,  57,
 242, 239, 183,  14, 102,  88, 208, 228, 166, 119, 114, 248, 235, 117,  75,  10,
  49,  68,  80, 180, 143, 237,  31,  26, 219, 153, 141,  51, 159,  17, 131,  20]
 
def dec2bin(n, count = 8):
        return "".join([str((n >> y) & 1) for y in range(count-1, -1, -1)])
 
def bin2dec(n):
        n = str(n)
        a = 0
        for i in range(len(n)):
                a = a + int(n[len(n) - i-1]) * (2**i)
        return a
 
# Appended to 16 bytes:
row = "01100001011000010110000101100001000011000000110000001100000011000000110000001100000011000000110000001100000011000000110000001100"
print "row_old =", row
N = len(row)/8
print "N =", N, "byte(s)"
M = []
C = []
L = 0
 
for i in range(16):
        C.append(0)
 
for i in range(N):
        M.append(row[i*8:i*8+8])
print "M =", M, "\n"
 
for i in range(15):
        C[i] = 0
 
for i in range(N/16):
        for j in range(16):
                c = bin2dec(M[i*16+j])
                C[j] = dec2bin(int(operator.xor(C[j], S[operator.xor(c, bin2dec(L))])))
                L = C[j]
                M.append(str(L))
                row += str(L)
print "Added controlsumm =", C, "\n"
print "row_new =", row, "\n"
 
N1 = N + 16
 
# STEP 3
print "STEP 3", "\n", "------"
X = []
for i in range(48):
        X.append(00000000)
print "X =", X, "\n"
 
# STEP 4
print "STEP 4", "\n", "------"
# Process each 16-word block
for i in range(N1/16):
        # Copy block i into X
        for j in range(16):
                X[16+j] = M[i*16+j]
                X[32+j] = operator.xor(int(X[16+j]), X[j])
                # end of loop on j
 
        t = 0
 
        # Do 18 rounds
        for j in range(18):
                # Round j
                for k in range(48):
#                       print k, " ", X[k], " ", S[t]
                        t = operator.xor(int(X[k]),S[t])
                        X[k] = t
                        # end of loop on k
                        t = operator.mod((t+j),256)
 
print "X =", X, "\n"
 
# STEP 5
print "STEP 5", "\n", "------"
md2sum_bin = ''
 
for i in range(16):
        md2sum_bin += dec2bin(X[i])
print "md2sum_bin =", md2sum_bin
 
md2sum = ''
for i in range(32):
        a = md2sum_bin[i*4:(i*4)+4]
        aa = bin2dec(a)
        aaa = hex(aa)[2:3]
        md2sum += aaa
 
print "md2sum =", md2sum