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- import time
- import copy
- class Rijndael(object):
- @classmethod
- def create(cls):
- if hasattr(cls, "RIJNDAEL_CREATED"):
- return
- # [keysize][block_size]
- cls.num_rounds = {16: {16: 10, 24: 12, 32: 14}, 24: {16: 12, 24: 12, 32: 14}, 32: {16: 14, 24: 14, 32: 14}}
- cls.shifts = [[[0, 0], [1, 3], [2, 2], [3, 1]],
- [[0, 0], [1, 5], [2, 4], [3, 3]],
- [[0, 0], [1, 7], [3, 5], [4, 4]]]
- A = [[1, 1, 1, 1, 1, 0, 0, 0],
- [0, 1, 1, 1, 1, 1, 0, 0],
- [0, 0, 1, 1, 1, 1, 1, 0],
- [0, 0, 0, 1, 1, 1, 1, 1],
- [1, 0, 0, 0, 1, 1, 1, 1],
- [1, 1, 0, 0, 0, 1, 1, 1],
- [1, 1, 1, 0, 0, 0, 1, 1],
- [1, 1, 1, 1, 0, 0, 0, 1]]
- # produce log and alog tables, needed for multiplying in the
- # field GF(2^m) (generator = 3)
- alog = [1]
- for i in range(255):
- j = (alog[-1] << 1) ^ alog[-1]
- if j & 0x100 != 0:
- j ^= 0x11B
- alog.append(j)
- log = [0] * 256
- for i in range(1, 255):
- log[alog[i]] = i
- # multiply two elements of GF(2^m)
- def mul(a, b):
- if a == 0 or b == 0:
- return 0
- return alog[(log[a & 0xFF] + log[b & 0xFF]) % 255]
- # substitution box based on F^{-1}(x)
- box = [[0] * 8 for i in range(256)]
- box[1][7] = 1
- for i in range(2, 256):
- j = alog[255 - log[i]]
- for t in range(8):
- box[i][t] = (j >> (7 - t)) & 0x01
- B = [0, 1, 1, 0, 0, 0, 1, 1]
- # affine transform: box[i] <- B + A*box[i]
- cox = [[0] * 8 for i in range(256)]
- for i in range(256):
- for t in range(8):
- cox[i][t] = B[t]
- for j in range(8):
- cox[i][t] ^= A[t][j] * box[i][j]
- # cls.S-boxes and inverse cls.S-boxes
- cls.S = [0] * 256
- cls.Si = [0] * 256
- for i in range(256):
- cls.S[i] = cox[i][0] << 7
- for t in range(1, 8):
- cls.S[i] ^= cox[i][t] << (7-t)
- cls.Si[cls.S[i] & 0xFF] = i
- # T-boxes
- G = [[2, 1, 1, 3],
- [3, 2, 1, 1],
- [1, 3, 2, 1],
- [1, 1, 3, 2]]
- AA = [[0] * 8 for i in range(4)]
- for i in range(4):
- for j in range(4):
- AA[i][j] = G[i][j]
- AA[i][i+4] = 1
- for i in range(4):
- pivot = AA[i][i]
- if pivot == 0:
- t = i + 1
- while AA[t][i] == 0 and t < 4:
- t += 1
- assert t != 4, 'G matrix must be invertible'
- for j in range(8):
- AA[i][j], AA[t][j] = AA[t][j], AA[i][j]
- pivot = AA[i][i]
- for j in range(8):
- if AA[i][j] != 0:
- AA[i][j] = alog[(255 + log[AA[i][j] & 0xFF] - log[pivot & 0xFF]) % 255]
- for t in range(4):
- if i != t:
- for j in range(i+1, 8):
- AA[t][j] ^= mul(AA[i][j], AA[t][i])
- AA[t][i] = 0
- iG = [[0] * 4 for i in range(4)]
- for i in range(4):
- for j in range(4):
- iG[i][j] = AA[i][j + 4]
- def mul4(a, bs):
- if a == 0:
- return 0
- r = 0
- for b in bs:
- r <<= 8
- if b != 0:
- r = r | mul(a, b)
- return r
- cls.T1 = []
- cls.T2 = []
- cls.T3 = []
- cls.T4 = []
- cls.T5 = []
- cls.T6 = []
- cls.T7 = []
- cls.T8 = []
- cls.U1 = []
- cls.U2 = []
- cls.U3 = []
- cls.U4 = []
- for t in range(256):
- s = cls.S[t]
- cls.T1.append(mul4(s, G[0]))
- cls.T2.append(mul4(s, G[1]))
- cls.T3.append(mul4(s, G[2]))
- cls.T4.append(mul4(s, G[3]))
- s = cls.Si[t]
- cls.T5.append(mul4(s, iG[0]))
- cls.T6.append(mul4(s, iG[1]))
- cls.T7.append(mul4(s, iG[2]))
- cls.T8.append(mul4(s, iG[3]))
- cls.U1.append(mul4(t, iG[0]))
- cls.U2.append(mul4(t, iG[1]))
- cls.U3.append(mul4(t, iG[2]))
- cls.U4.append(mul4(t, iG[3]))
- # round constants
- cls.rcon = [1]
- r = 1
- for t in range(1, 30):
- r = mul(2, r)
- cls.rcon.append(r)
- cls.RIJNDAEL_CREATED = True
- def __init__(self, key, block_size = 16):
- # create common meta-instance infrastructure
- self.create()
- if block_size != 16 and block_size != 24 and block_size != 32:
- raise ValueError('Invalid block size: ' + str(block_size))
- if len(key) != 16 and len(key) != 24 and len(key) != 32:
- raise ValueError('Invalid key size: ' + str(len(key)))
- self.block_size = block_size
- ROUNDS = Rijndael.num_rounds[len(key)][block_size]
- BC = int(block_size / 4)
- # encryption round keys
- Ke = [[0] * BC for i in range(ROUNDS + 1)]
- # decryption round keys
- Kd = [[0] * BC for i in range(ROUNDS + 1)]
- ROUND_KEY_COUNT = (ROUNDS + 1) * BC
- KC = int(len(key) / 4)
- # copy user material bytes into temporary ints
- tk = []
- for i in range(0, KC):
- tk.append((ord(key[i * 4]) << 24) | (ord(key[i * 4 + 1]) << 16) |
- (ord(key[i * 4 + 2]) << 8) | ord(key[i * 4 + 3]))
- # copy values into round key arrays
- t = 0
- j = 0
- while j < KC and t < ROUND_KEY_COUNT:
- Ke[int(t / BC)][t % BC] = tk[j]
- Kd[ROUNDS - (int(t / BC))][t % BC] = tk[j]
- j += 1
- t += 1
- tt = 0
- rconpointer = 0
- while t < ROUND_KEY_COUNT:
- # extrapolate using phi (the round key evolution function)
- tt = tk[KC - 1]
- tk[0] ^= (Rijndael.S[(tt >> 16) & 0xFF] & 0xFF) << 24 ^ \
- (Rijndael.S[(tt >> 8) & 0xFF] & 0xFF) << 16 ^ \
- (Rijndael.S[ tt & 0xFF] & 0xFF) << 8 ^ \
- (Rijndael.S[(tt >> 24) & 0xFF] & 0xFF) ^ \
- (Rijndael.rcon[rconpointer] & 0xFF) << 24
- rconpointer += 1
- if KC != 8:
- for i in range(1, KC):
- tk[i] ^= tk[i-1]
- else:
- for i in range(1, int(KC / 2)):
- tk[i] ^= tk[i-1]
- tt = tk[int(KC / 2 - 1)]
- tk[int(KC / 2)] ^= (Rijndael.S[ tt & 0xFF] & 0xFF) ^ \
- (Rijndael.S[(tt >> 8) & 0xFF] & 0xFF) << 8 ^ \
- (Rijndael.S[(tt >> 16) & 0xFF] & 0xFF) << 16 ^ \
- (Rijndael.S[(tt >> 24) & 0xFF] & 0xFF) << 24
- for i in range(int(KC / 2) + 1, KC):
- tk[i] ^= tk[i-1]
- # copy values into round key arrays
- j = 0
- while j < KC and t < ROUND_KEY_COUNT:
- Ke[int(t / BC)][t % BC] = tk[j]
- Kd[ROUNDS - (int(t / BC))][t % BC] = tk[j]
- j += 1
- t += 1
- # inverse MixColumn where needed
- for r in range(1, ROUNDS):
- for j in range(BC):
- tt = Kd[r][j]
- Kd[r][j] = Rijndael.U1[(tt >> 24) & 0xFF] ^ \
- Rijndael.U2[(tt >> 16) & 0xFF] ^ \
- Rijndael.U3[(tt >> 8) & 0xFF] ^ \
- Rijndael.U4[ tt & 0xFF]
- self.Ke = Ke
- self.Kd = Kd
- def encrypt(self, plaintext):
- if len(plaintext) != self.block_size:
- raise ValueError('wrong block length, expected ' + str(self.block_size) + ' got ' + str(len(plaintext)))
- Ke = self.Ke
- BC = int(self.block_size / 4)
- ROUNDS = len(Ke) - 1
- if BC == 4:
- Rijndael.SC = 0
- elif BC == 6:
- Rijndael.SC = 1
- else:
- Rijndael.SC = 2
- s1 = Rijndael.shifts[Rijndael.SC][1][0]
- s2 = Rijndael.shifts[Rijndael.SC][2][0]
- s3 = Rijndael.shifts[Rijndael.SC][3][0]
- a = [0] * BC
- # temporary work array
- t = []
- # plaintext to ints + key
- for i in range(BC):
- t.append((ord(plaintext[i * 4 ]) << 24 |
- ord(plaintext[i * 4 + 1]) << 16 |
- ord(plaintext[i * 4 + 2]) << 8 |
- ord(plaintext[i * 4 + 3]) ) ^ Ke[0][i])
- # apply round transforms
- for r in range(1, ROUNDS):
- for i in range(BC):
- a[i] = (Rijndael.T1[(t[ i ] >> 24) & 0xFF] ^
- Rijndael.T2[(t[(i + s1) % BC] >> 16) & 0xFF] ^
- Rijndael.T3[(t[(i + s2) % BC] >> 8) & 0xFF] ^
- Rijndael.T4[ t[(i + s3) % BC] & 0xFF] ) ^ Ke[r][i]
- t = copy.deepcopy(a)
- # last round is special
- result = []
- for i in range(BC):
- tt = Ke[ROUNDS][i]
- result.append((Rijndael.S[(t[ i ] >> 24) & 0xFF] ^ (tt >> 24)) & 0xFF)
- result.append((Rijndael.S[(t[(i + s1) % BC] >> 16) & 0xFF] ^ (tt >> 16)) & 0xFF)
- result.append((Rijndael.S[(t[(i + s2) % BC] >> 8) & 0xFF] ^ (tt >> 8)) & 0xFF)
- result.append((Rijndael.S[ t[(i + s3) % BC] & 0xFF] ^ tt ) & 0xFF)
- return ''.join(list(map(chr, result)))
- def decrypt(self, ciphertext):
- if len(ciphertext) != self.block_size:
- raise ValueError('wrong block length, expected ' + str(self.block_size) + ' got ' + str(len(ciphertext)))
- Kd = self.Kd
- BC = int(self.block_size / 4)
- ROUNDS = len(Kd) - 1
- if BC == 4:
- Rijndael.SC = 0
- elif BC == 6:
- Rijndael.SC = 1
- else:
- Rijndael.SC = 2
- s1 = Rijndael.shifts[Rijndael.SC][1][1]
- s2 = Rijndael.shifts[Rijndael.SC][2][1]
- s3 = Rijndael.shifts[Rijndael.SC][3][1]
- a = [0] * BC
- # temporary work array
- t = [0] * BC
- # ciphertext to ints + key
- for i in range(BC):
- t[i] = (ord(ciphertext[i * 4 ]) << 24 |
- ord(ciphertext[i * 4 + 1]) << 16 |
- ord(ciphertext[i * 4 + 2]) << 8 |
- ord(ciphertext[i * 4 + 3]) ) ^ Kd[0][i]
- # apply round transforms
- for r in range(1, ROUNDS):
- for i in range(BC):
- a[i] = (Rijndael.T5[(t[ i ] >> 24) & 0xFF] ^
- Rijndael.T6[(t[(i + s1) % BC] >> 16) & 0xFF] ^
- Rijndael.T7[(t[(i + s2) % BC] >> 8) & 0xFF] ^
- Rijndael.T8[ t[(i + s3) % BC] & 0xFF] ) ^ Kd[r][i]
- t = copy.deepcopy(a)
- # last round is special
- result = []
- for i in range(BC):
- tt = Kd[ROUNDS][i]
- result.append((Rijndael.Si[(t[ i ] >> 24) & 0xFF] ^ (tt >> 24)) & 0xFF)
- result.append((Rijndael.Si[(t[(i + s1) % BC] >> 16) & 0xFF] ^ (tt >> 16)) & 0xFF)
- result.append((Rijndael.Si[(t[(i + s2) % BC] >> 8) & 0xFF] ^ (tt >> 8)) & 0xFF)
- result.append((Rijndael.Si[ t[(i + s3) % BC] & 0xFF] ^ tt ) & 0xFF)
- return ''.join(list(map(chr, result)))
- # @staticmethod
- # def encrypt_block(key, block):
- # return Rijndael(key, len(block)).encrypt(block)
- # @staticmethod
- # def decrypt_block(key, block):
- # return Rijndael(key, len(block)).decrypt(block)
- @staticmethod
- def test():
- def t(kl, bl):
- b = 'b' * bl
- r = Rijndael('a' * kl, bl)
- x = r.encrypt(b)
- assert x != b
- assert r.decrypt(x) == b
- t(16, 16)
- t(16, 24)
- t(16, 32)
- t(24, 16)
- t(24, 24)
- t(24, 32)
- t(32, 16)
- t(32, 24)
- t(32, 32)
- start = time.time()
- r = Rijndael("abcdefg1234567890123456789012345", block_size = 32)
- ciphertext = r.encrypt("12345999999999999999999999954321")
- end = time.time()
- plaintext = r.decrypt(ciphertext)
- #print (plaintext,ciphertext)
- a=end-start
- print (a)
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