def final(self):
i = OpenSSL.c_int(0)
buffer = OpenSSL.malloc(b"", self.cipher.get_blocksize())
if (OpenSSL.EVP_CipherFinal_ex(self.ctx, OpenSSL.byref(buffer),
OpenSSL.byref(i))) == 0:
raise Exception("[OpenSSL] EVP_CipherFinal_ex FAIL ...")
return buffer.raw[0:i.value]
def raw_encrypt(data, pubkey_x, pubkey_y, curve='sect283r1',
ephemcurve=None, ciphername='aes-256-cbc'):
if ephemcurve is None:
ephemcurve = curve
ephem = ECC(curve=ephemcurve)
key = sha512(ephem.raw_get_ecdh_key(pubkey_x, pubkey_y)).digest()
key_e, key_m = key[:32], key[32:]
pubkey = ephem.get_pubkey()
iv = OpenSSL.rand(OpenSSL.get_cipher(ciphername).get_blocksize())
ctx = Cipher(key_e, iv, 1, ciphername)
ciphertext = ctx.ciphering(data)
mac = hmac_sha256(key_m, ciphertext)
return iv + pubkey + ciphertext + mac
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()
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 hmac_sha256(k, m):
"""
Compute the key and the message with HMAC SHA5256
"""
key = OpenSSL.malloc(k, len(k))
d = OpenSSL.malloc(m, len(m))
md = OpenSSL.malloc(0, 32)
i = OpenSSL.pointer(OpenSSL.c_int(0))
OpenSSL.HMAC(OpenSSL.EVP_sha256(), key, len(k), d, len(m), md, i)
return md.raw
def update(self, input):
i = OpenSSL.c_int(0)
buffer = OpenSSL.malloc(b"", len(input) + self.cipher.get_blocksize())
inp = OpenSSL.malloc(input, len(input))
if OpenSSL.EVP_CipherUpdate(self.ctx, OpenSSL.byref(buffer),
OpenSSL.byref(i), inp, len(input)) == 0:
raise Exception("[OpenSSL] EVP_CipherUpdate FAIL ...")
return buffer.raw[0:i.value]
def pbkdf2(password, salt=None, i=10000, keylen=64):
if salt is None:
salt = OpenSSL.rand(8)
p_password = OpenSSL.malloc(password, len(password))
p_salt = OpenSSL.malloc(salt, len(salt))
output = OpenSSL.malloc(0, keylen)
OpenSSL.PKCS5_PBKDF2_HMAC(p_password, len(password), p_salt, len(p_salt),
i, OpenSSL.EVP_sha256(), keylen, output)
return salt, output.raw
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
ciphertext = data[i:len(data)-32]
i += len(ciphertext)
mac = data[i:]
key = sha512(self.raw_get_ecdh_key(pubkey_x, pubkey_y)).digest()
key_e, key_m = key[:32], key[32:]
if hmac_sha256(key_m, ciphertext) != mac:
raise RuntimeError("Fail to verify data")
ctx = Cipher(key_e, iv, 0, ciphername)
return ctx.ciphering(ciphertext)
def __init__(self, pubkey=None, privkey=None, pubkey_x=None,
pubkey_y=None, raw_privkey=None, curve='sect283r1'):
"""
For a normal and High level use, specifie pubkey,
privkey (if you need) and the curve
"""
if type(curve) == str:
self.curve = OpenSSL.get_curve(curve)
else:
self.curve = curve
if pubkey_x is not None and pubkey_y is not None:
self._set_keys(pubkey_x, pubkey_y, raw_privkey)
elif pubkey is not None:
curve, pubkey_x, pubkey_y, i = ECC._decode_pubkey(pubkey)
if privkey is not None:
curve2, raw_privkey, i = ECC._decode_privkey(privkey)
if curve != curve2:
raise Exception("Bad ECC keys ...")
self.curve = curve
self._set_keys(pubkey_x, pubkey_y, raw_privkey)
else:
self.privkey, self.pubkey_x, self.pubkey_y = self._generate()
def verify(self, sig, inputb):
"""
Verify the signature with the input and the local public key.
Returns a boolean
"""
try:
bsig = OpenSSL.malloc(sig, len(sig))
binputb = OpenSSL.malloc(inputb, len(inputb))
digest = OpenSSL.malloc(0, 64)
dgst_len = OpenSSL.pointer(OpenSSL.c_int(0))
md_ctx = OpenSSL.EVP_MD_CTX_create()
key = OpenSSL.EC_KEY_new_by_curve_name(self.curve)
if key == 0:
raise Exception("[OpenSSL] EC_KEY_new_by_curve_name FAIL ...")
pub_key_x = OpenSSL.BN_bin2bn(self.pubkey_x, len(self.pubkey_x), 0)
pub_key_y = OpenSSL.BN_bin2bn(self.pubkey_y, len(self.pubkey_y), 0)
group = OpenSSL.EC_KEY_get0_group(key)
pub_key = OpenSSL.EC_POINT_new(group)
if (OpenSSL.EC_POINT_set_affine_coordinates_GFp(group, pub_key,
pub_key_x,
pub_key_y,
0)) == 0:
raise Exception(
"[OpenSSL] EC_POINT_set_affine_coordinates_GFp FAIL ...")
if (OpenSSL.EC_KEY_set_public_key(key, pub_key)) == 0:
raise Exception("[OpenSSL] EC_KEY_set_public_key FAIL ...")
if (OpenSSL.EC_KEY_check_key(key)) == 0:
raise Exception("[OpenSSL] EC_KEY_check_key FAIL ...")
OpenSSL.EVP_MD_CTX_init(md_ctx)
OpenSSL.EVP_DigestInit(md_ctx, OpenSSL.EVP_ecdsa())
if (OpenSSL.EVP_DigestUpdate(md_ctx, binputb, len(inputb))) == 0:
raise Exception("[OpenSSL] EVP_DigestUpdate FAIL ...")
OpenSSL.EVP_DigestFinal(md_ctx, digest, dgst_len)
ret = OpenSSL.ECDSA_verify(
0, digest, dgst_len.contents, bsig, len(sig), key)
if ret == -1:
return False # Fail to Check
else:
if ret == 0:
return False # Bad signature !
else:
return True # Good
return False
finally:
OpenSSL.EC_KEY_free(key)
OpenSSL.BN_free(pub_key_x)
OpenSSL.BN_free(pub_key_y)
OpenSSL.EC_POINT_free(pub_key)
OpenSSL.EVP_MD_CTX_destroy(md_ctx)
def sign(self, inputb):
"""
Sign the input with ECDSA method and returns the signature
"""
try:
size = len(inputb)
buff = OpenSSL.malloc(inputb, size)
digest = OpenSSL.malloc(0, 64)
md_ctx = OpenSSL.EVP_MD_CTX_create()
dgst_len = OpenSSL.pointer(OpenSSL.c_int(0))
siglen = OpenSSL.pointer(OpenSSL.c_int(0))
sig = OpenSSL.malloc(0, 151)
key = OpenSSL.EC_KEY_new_by_curve_name(self.curve)
if key == 0:
raise Exception("[OpenSSL] EC_KEY_new_by_curve_name FAIL ...")
priv_key = OpenSSL.BN_bin2bn(self.privkey, len(self.privkey), 0)
pub_key_x = OpenSSL.BN_bin2bn(self.pubkey_x, len(self.pubkey_x), 0)
pub_key_y = OpenSSL.BN_bin2bn(self.pubkey_y, len(self.pubkey_y), 0)
if (OpenSSL.EC_KEY_set_private_key(key, priv_key)) == 0:
raise Exception("[OpenSSL] EC_KEY_set_private_key FAIL ...")
group = OpenSSL.EC_KEY_get0_group(key)
pub_key = OpenSSL.EC_POINT_new(group)
if (OpenSSL.EC_POINT_set_affine_coordinates_GFp(group, pub_key,
pub_key_x,
pub_key_y,
0)) == 0:
raise Exception(
"[OpenSSL] EC_POINT_set_affine_coordinates_GFp FAIL ...")
if (OpenSSL.EC_KEY_set_public_key(key, pub_key)) == 0:
raise Exception("[OpenSSL] EC_KEY_set_public_key FAIL ...")
if (OpenSSL.EC_KEY_check_key(key)) == 0:
raise Exception("[OpenSSL] EC_KEY_check_key FAIL ...")
OpenSSL.EVP_MD_CTX_init(md_ctx)
OpenSSL.EVP_DigestInit(md_ctx, OpenSSL.EVP_ecdsa())
if (OpenSSL.EVP_DigestUpdate(md_ctx, buff, size)) == 0:
raise Exception("[OpenSSL] EVP_DigestUpdate FAIL ...")
OpenSSL.EVP_DigestFinal(md_ctx, digest, dgst_len)
OpenSSL.ECDSA_sign(0, digest, dgst_len.contents, sig, siglen, key)
if (OpenSSL.ECDSA_verify(0, digest, dgst_len.contents, sig,
siglen.contents, key)) != 1:
raise Exception("[OpenSSL] ECDSA_verify FAIL ...")
return sig.raw[:siglen.contents.value]
finally:
OpenSSL.EC_KEY_free(key)
OpenSSL.BN_free(pub_key_x)
OpenSSL.BN_free(pub_key_y)
OpenSSL.BN_free(priv_key)
OpenSSL.EC_POINT_free(pub_key)
OpenSSL.EVP_MD_CTX_destroy(md_ctx)
def raw_check_key(self, privkey, pubkey_x, pubkey_y, curve=None):
if curve is None:
curve = self.curve
elif type(curve) == str:
curve = OpenSSL.get_curve(curve)
else:
curve = curve
try:
key = OpenSSL.EC_KEY_new_by_curve_name(curve)
if key == 0:
raise Exception("[OpenSSL] EC_KEY_new_by_curve_name FAIL ...")
if privkey is not None:
priv_key = OpenSSL.BN_bin2bn(privkey, len(privkey), 0)
pub_key_x = OpenSSL.BN_bin2bn(pubkey_x, len(pubkey_x), 0)
pub_key_y = OpenSSL.BN_bin2bn(pubkey_y, len(pubkey_y), 0)
if privkey is not None:
if (OpenSSL.EC_KEY_set_private_key(key, priv_key)) == 0:
raise Exception(
"[OpenSSL] EC_KEY_set_private_key FAIL ...")
group = OpenSSL.EC_KEY_get0_group(key)
pub_key = OpenSSL.EC_POINT_new(group)
if (OpenSSL.EC_POINT_set_affine_coordinates_GFp(group, pub_key,
pub_key_x,
pub_key_y,
0)) == 0:
raise Exception(
"[OpenSSL] EC_POINT_set_affine_coordinates_GFp FAIL ...")
if (OpenSSL.EC_KEY_set_public_key(key, pub_key)) == 0:
raise Exception("[OpenSSL] EC_KEY_set_public_key FAIL ...")
if (OpenSSL.EC_KEY_check_key(key)) == 0:
raise Exception("[OpenSSL] EC_KEY_check_key FAIL ...")
return 0
finally:
OpenSSL.EC_KEY_free(key)
OpenSSL.BN_free(pub_key_x)
OpenSSL.BN_free(pub_key_y)
OpenSSL.EC_POINT_free(pub_key)
if privkey is not None:
OpenSSL.BN_free(priv_key)
def raw_get_ecdh_key(self, pubkey_x, pubkey_y):
try:
ecdh_keybuffer = OpenSSL.malloc(0, 32)
other_key = OpenSSL.EC_KEY_new_by_curve_name(self.curve)
if other_key == 0:
raise Exception("[OpenSSL] EC_KEY_new_by_curve_name FAIL ...")
other_pub_key_x = OpenSSL.BN_bin2bn(pubkey_x, len(pubkey_x), 0)
other_pub_key_y = OpenSSL.BN_bin2bn(pubkey_y, len(pubkey_y), 0)
other_group = OpenSSL.EC_KEY_get0_group(other_key)
other_pub_key = OpenSSL.EC_POINT_new(other_group)
if (OpenSSL.EC_POINT_set_affine_coordinates_GFp(other_group,
other_pub_key,
other_pub_key_x,
other_pub_key_y,
0)) == 0:
raise Exception(
"[OpenSSL] EC_POINT_set_affine_coordinates_GFp FAIL ...")
if (OpenSSL.EC_KEY_set_public_key(other_key, other_pub_key)) == 0:
raise Exception("[OpenSSL] EC_KEY_set_public_key FAIL ...")
if (OpenSSL.EC_KEY_check_key(other_key)) == 0:
raise Exception("[OpenSSL] EC_KEY_check_key FAIL ...")
own_key = OpenSSL.EC_KEY_new_by_curve_name(self.curve)
if own_key == 0:
raise Exception("[OpenSSL] EC_KEY_new_by_curve_name FAIL ...")
own_priv_key = OpenSSL.BN_bin2bn(
self.privkey, len(self.privkey), 0)
if (OpenSSL.EC_KEY_set_private_key(own_key, own_priv_key)) == 0:
raise Exception("[OpenSSL] EC_KEY_set_private_key FAIL ...")
OpenSSL.ECDH_set_method(own_key, OpenSSL.ECDH_OpenSSL())
ecdh_keylen = OpenSSL.ECDH_compute_key(
ecdh_keybuffer, 32, other_pub_key, own_key, 0)
if ecdh_keylen != 32:
raise Exception("[OpenSSL] ECDH keylen FAIL ...")
return ecdh_keybuffer.raw
finally:
OpenSSL.EC_KEY_free(other_key)
OpenSSL.BN_free(other_pub_key_x)
OpenSSL.BN_free(other_pub_key_y)
OpenSSL.EC_POINT_free(other_pub_key)
OpenSSL.EC_KEY_free(own_key)
OpenSSL.BN_free(own_priv_key)
def __del__(self):
OpenSSL.EVP_CIPHER_CTX_cleanup(self.ctx)
OpenSSL.EVP_CIPHER_CTX_free(self.ctx)
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()
def get_curve(self):
return OpenSSL.get_curve_by_id(self.curve)
def _generate(self):
try:
pub_key_x = OpenSSL.BN_new()
pub_key_y = OpenSSL.BN_new()
key = OpenSSL.EC_KEY_new_by_curve_name(self.curve)
if key == 0:
raise Exception("[OpenSSL] EC_KEY_new_by_curve_name FAIL ...")
if (OpenSSL.EC_KEY_generate_key(key)) == 0:
raise Exception("[OpenSSL] EC_KEY_generate_key FAIL ...")
if (OpenSSL.EC_KEY_check_key(key)) == 0:
raise Exception("[OpenSSL] EC_KEY_check_key FAIL ...")
priv_key = OpenSSL.EC_KEY_get0_private_key(key)
group = OpenSSL.EC_KEY_get0_group(key)
pub_key = OpenSSL.EC_KEY_get0_public_key(key)
if (OpenSSL.EC_POINT_get_affine_coordinates_GFp(group, pub_key,
pub_key_x,
pub_key_y, 0
)) == 0:
raise Exception(
"[OpenSSL] EC_POINT_get_affine_coordinates_GFp FAIL ...")
privkey = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(priv_key))
pubkeyx = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(pub_key_x))
pubkeyy = OpenSSL.malloc(0, OpenSSL.BN_num_bytes(pub_key_y))
OpenSSL.BN_bn2bin(priv_key, privkey)
privkey = privkey.raw
OpenSSL.BN_bn2bin(pub_key_x, pubkeyx)
pubkeyx = pubkeyx.raw
OpenSSL.BN_bn2bin(pub_key_y, pubkeyy)
pubkeyy = pubkeyy.raw
self.raw_check_key(privkey, pubkeyx, pubkeyy)
return privkey, pubkeyx, pubkeyy
finally:
OpenSSL.EC_KEY_free(key)
OpenSSL.BN_free(pub_key_x)
OpenSSL.BN_free(pub_key_y)
