def raw_encrypt(data, pubkey_x, pubkey_y, curve='sect283r1', ephemcurve=None, ciphername='aes-256-cbc'):
if ephemcurve == None: ephemcurve = curve
ephem = ecc(curve=ephemcurve)
key = ephem.raw_get_ecdh_key(pubkey_x, pubkey_y)
pubkey = ephem.get_pubkey()
iv = openssl.rand(openssl.get_cipher(ciphername).get_blocksize())
ctx = cipher(key, iv, 1, ciphername)
return iv + pubkey + ctx.ciphering(data)
def decrypt(self, data, ciphername='aes-256-cbc'):
"""
Decrypt data with ECIES method using the local private key
"""
blocksize = openssl.get_cipher(ciphername).get_blocksize()
iv = data[:blocksize]
i = blocksize
curve, pubkey_x, pubkey_y, i2 = ecc._decode_pubkey(data[i:])
i += i2
data = data[i:]
key = self.raw_get_ecdh_key(pubkey_x, pubkey_y)
ctx = cipher(key, iv, 0, ciphername)
return ctx.ciphering(data)
def __init__(self, key, iv, do, ciphername='aes-256-cbc'):
"""
do == 1 => Encrypt; do == 0 => Decrypt
"""
self.cipher = openssl.get_cipher(ciphername)
self.ctx = openssl.EVP_CIPHER_CTX_new()
self.ciphertext = b""
self.size = 0
if do == 1 or do == 0:
k = openssl.malloc(key, len(key))
IV = openssl.malloc(iv, len(iv))
openssl.EVP_CipherInit_ex(self.ctx, self.cipher.get_pointer(), 0, k, IV, do)
else:
raise Exception("RTFM ...")
def gen_IV(ciphername):
cipher = openssl.get_cipher(ciphername)
return openssl.rand(cipher.get_blocksize())
def get_blocksize(ciphername):
cipher = openssl.get_cipher(ciphername)
return cipher.get_blocksize()
