search

nasa / CryptoLib

Provide a software-only solution using the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between a spacecraft running the core Flight System (cFS) and a ground station.
Other
66 stars 25 forks source link

PDU length bits vs bytes #224

Open martinerikwerner-aac opened 4 months ago

martinerikwerner-aac commented 4 months ago

CCSDS 355.1-B-1 indicates that the length field of EP PDUs should be the length of the PDU data field in bits:

5.3.2.3.1 The Extended Procedures Data Field Length shall signal the length of the Extended Procedures PDU Data Field in bits.

This is also indicated by the declaration in:

https://github.com/nasa/CryptoLib/blob/ef64d8d1346ead848415939a21beb8dfa9fe29d3/include/crypto_structs.h#L107

However, the use of this field seems to treat is as the number of octets, for example:

https://github.com/nasa/CryptoLib/blob/ef64d8d1346ead848415939a21beb8dfa9fe29d3/src/core/crypto_mc.c#L169-L171

https://github.com/nasa/CryptoLib/blob/ef64d8d1346ead848415939a21beb8dfa9fe29d3/src/core/crypto.c#L270-L271

rjbrown2 commented 3 months ago

Hi martinerikwerner-aac. Thanks for bringing this to our attention. We have not yet worked on Extended procedures at this time - so the tests are currently broken. This is on our short-term roadmap, and we will leave this issue open for tracking and completion. Thanks again!