1 files changed, 58 insertions, 0 deletions
diff --git a/src/leap/mx/vendor/pgpy/symenc.py b/src/leap/mx/vendor/pgpy/symenc.py
new file mode 100644
index 0000000..3d81a7c
--- /dev/null
+++ b/src/leap/mx/vendor/pgpy/symenc.py
@@ -0,0 +1,58 @@
+""" symenc.py
+"""
+import six
+
+from cryptography.exceptions import UnsupportedAlgorithm
+
+from cryptography.hazmat.backends import default_backend
+
+from cryptography.hazmat.primitives.ciphers import Cipher
+from cryptography.hazmat.primitives.ciphers import modes
+
+from .errors import PGPDecryptionError
+from .errors import PGPEncryptionError
+from .errors import PGPInsecureCipher
+
+__all__ = ['_encrypt',
+           '_decrypt']
+
+
+def _encrypt(pt, key, alg, iv=None):
+    if iv is None:
+        iv = b'\x00' * (alg.block_size // 8)
+
+    if alg.is_insecure:
+        raise PGPInsecureCipher("{:s} is not secure. Do not use it for encryption!".format(alg.name))
+
+    if not callable(alg.cipher):
+        raise PGPEncryptionError("Cipher {:s} not supported".format(alg.name))
+
+    try:
+        encryptor = Cipher(alg.cipher(key), modes.CFB(iv), default_backend()).encryptor()
+
+    except UnsupportedAlgorithm as ex:  # pragma: no cover
+        six.raise_from(PGPEncryptionError, ex)
+
+    else:
+        return bytearray(encryptor.update(pt) + encryptor.finalize())
+
+
+def _decrypt(ct, key, alg, iv=None):
+    if iv is None:
+        """
+        Instead of using an IV, OpenPGP prefixes a string of length
+        equal to the block size of the cipher plus two to the data before it
+        is encrypted. The first block-size octets (for example, 8 octets for
+        a 64-bit block length) are random, and the following two octets are
+        copies of the last two octets of the IV.
+        """
+        iv = b'\x00' * (alg.block_size // 8)
+
+    try:
+        decryptor = Cipher(alg.cipher(key), modes.CFB(iv), default_backend()).decryptor()
+
+    except UnsupportedAlgorithm as ex:  # pragma: no cover
+        six.raise_from(PGPDecryptionError, ex)
+
+    else:
+        return bytearray(decryptor.update(ct) + decryptor.finalize())