def encrypt(key,
msg,
iv=None,
alg="aes_128_cbc",
padding="PKCS#7",
b64enc=True,
block_size=BLOCK_SIZE):
"""
:param key: The encryption key
:param iv: init vector
:param msg: Message to be encrypted
:param padding: Which padding that should be used
:param b64enc: Whether the result should be base64encoded
:param block_size: If PKCS#7 padding which block size to use
:return: The encrypted message
"""
if padding == "PKCS#7":
_block_size = block_size
elif padding == "PKCS#5":
_block_size = 8
else:
_block_size = 0
if _block_size:
plen = _block_size - (len(msg) % _block_size)
c = chr(plen)
msg += (c * plen)
cipher, iv = build_cipher(tobytes(key), iv, alg)
cmsg = iv + cipher.encrypt(tobytes(msg))
if b64enc:
return b64encode(cmsg)
else:
return cmsg
def build_cipher(key, iv, alg="aes_128_cbc"):
"""
Create cipher.
:param key: encryption key
:param iv: init vector
:param alg: cipher algorithm
:return: A Cipher instance
"""
_, bits, cmode = alg.split("_")
if not iv:
iv = Random.new().read(AES.block_size)
else:
assert len(iv) == AES.block_size
if bits not in ["128", "192", "256"]:
raise AESError("Unsupported key length")
if len(key) != int(bits) >> 3:
raise AESError("Wrong Key length")
try:
return AES.new(tobytes(key), POSTFIX_MODE[cmode], tobytes(iv)), iv
except KeyError:
raise AESError("Unsupported chaining mode")
def encrypt(key, msg, iv=None, alg="aes_128_cbc", padding="PKCS#7",
b64enc=True, block_size=BLOCK_SIZE):
"""
:param key: The encryption key
:param iv: init vector
:param msg: Message to be encrypted
:param padding: Which padding that should be used
:param b64enc: Whether the result should be base64encoded
:param block_size: If PKCS#7 padding which block size to use
:return: The encrypted message
"""
if padding == "PKCS#7":
_block_size = block_size
elif padding == "PKCS#5":
_block_size = 8
else:
_block_size = 0
if _block_size:
plen = _block_size - (len(msg) % _block_size)
c = chr(plen)
msg += (c * plen)
cipher, iv = build_cipher(tobytes(key), iv, alg)
cmsg = iv + cipher.encrypt(tobytes(msg))
if b64enc:
return b64encode(cmsg)
else:
return cmsg
def build_cipher(key, iv, alg="aes_128_cbc"):
"""
:param key: encryption key
:param iv: init vector
:param alg: cipher algorithm
:return: A Cipher instance
"""
_, bits, cmode = alg.split("_")
if not iv:
iv = Random.new().read(AES.block_size)
else:
assert len(iv) == AES.block_size
if bits not in ["128", "192", "256"]:
raise AESError("Unsupported key length")
if len(key) != int(bits) >> 3:
raise AESError("Wrong Key length")
try:
return AES.new(tobytes(key), POSTFIX_MODE[cmode], tobytes(iv)), iv
except KeyError:
raise AESError("Unsupported chaining mode")
def encrypt(self, text):
# Padding to blocksize of AES
text = tobytes(text)
if len(text) % 16:
text += b' ' * (16 - len(text) % 16)
return self.core.encrypt(tobytes(text))
def encrypt(self, text):
# Padding to blocksize of AES
text = tobytes(text)
if len(text) % 16:
text += b' ' * (16 - len(text) % 16)
return self.core.encrypt(tobytes(text))