[XS] Change in pysim[master]: scp: fix key length in dek_encrypt and dek_decrypt

Attention is currently required from: laforge. dexter has posted comments on this change by dexter. ( https://gerrit.osmocom.org/c/pysim/+/37931?usp=email ) Change subject: scp: fix key length in dek_encrypt and dek_decrypt ...................................................................... Patch Set 2: (1 comment) Commit Message: https://gerrit.osmocom.org/c/pysim/+/37931/comment/74c33d5e_037b1da9?usp=em… : PS1, Line 9: When creating the DES cipher object with DES.new, we use the property : card_keys.dek. This property may hold a 16 byte key, but DES uses : an 8 byte key. Pycryptodome does not automatically ignore excess key : bytes. Instead it throws an exception. This means we need to make sure : to supply only the first 8 bytes of card_keys.dek Yes, I have checked it. It seems to be an implementation detail of pyCryptoDome. They say: "key (bytes/bytearray/memoryview) – The secret key to use in the symmetric cipher. It must be 8 byte long. The parity bits will be ignored." In other code locations one can find the truncation as well. I have now put a reference to the pyCryptoDome manual into the commit message. I don't think that we need an extra comment in the code, since it is only a pyCryptoDome related. -- To view, visit https://gerrit.osmocom.org/c/pysim/+/37931?usp=email To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings?usp=email Gerrit-MessageType: comment Gerrit-Project: pysim Gerrit-Branch: master Gerrit-Change-Id: I92e0dc6a6196b532bd8b53fca7b9e78070d6903f Gerrit-Change-Number: 37931 Gerrit-PatchSet: 2 Gerrit-Owner: dexter <pmaier(a)sysmocom.de> Gerrit-Reviewer: Jenkins Builder Gerrit-CC: laforge <laforge(a)osmocom.org> Gerrit-Attention: laforge <laforge(a)osmocom.org> Gerrit-Comment-Date: Wed, 28 Aug 2024 12:48:55 +0000 Gerrit-HasComments: Yes Gerrit-Has-Labels: No Comment-In-Reply-To: laforge <laforge(a)osmocom.org>