added decrypt example in python

1 files changed, 36 insertions, 0 deletions

diff --git a/usb-crypto/decrypt.py b/usb-crypto/decrypt.py
new file mode 100755
index 0000000..7f7151a
--- /dev/null
+++ b/usb-crypto/decrypt.py
@@ -0,0 +1,36 @@
+#!/usr/bin/python
+#
+# spreadspace avr utils
+#
+#
+# Copyright (C) 2013-2016 Christian Pointner <equinox@spreadspace.org>
+#
+# This file is part of spreadspace avr utils.
+#
+# spreadspace avr utils is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# any later version.
+#
+# spreadspace avr utils is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
+#
+
+import binascii
+from cryptography.hazmat.primitives.ciphers.aead import ChaCha20Poly1305
+
+hdr = "hello world!"
+body_enc = binascii.unhexlify("5535BB923FB4BDCA401D3AE05C85FF314BD22423FE339CD00259551AECA534FABBEB16B39CC9AC14DF")
+
+key = binascii.unhexlify("7043b69bde20446661ba579e83fda0830e3e61c95b5ac8deeb79973ba0df02d8")
+iv = binascii.unhexlify("6fac1c6a94a5788761cf9ecd")
+
+cipher = ChaCha20Poly1305(key)
+msg = cipher.decrypt(iv, body_enc, hdr)
+
+print(str(msg))