Participants can sign their own permissions file if the same CA is used for both identity and permissions #3992
+41
−7
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Problem
Assume a usage of DDS Security where the same CA is used for both permissions and identity. The certificates issued to particpants allow them to sign documents. Assume the participant generates a permissions file and then signs it. Chain verification causes verification attempts to succeed since the signing certificate, i.e., the participant's certificate, can be chained back to the permission CA's certificate (which is also the identity CA).
This problem was identified in
ros2/sros2#282.
Solution
Implement the suggestion in ros2/sros2#282. Specifically, use PKCS7_NOINTERN to not accept any signatures in the signed document. This, in turn, requires the use of the
certs
parameter toPKCS7_verify
. PKCS7_NOVERIFY is used since the permissions CA certificate will not be chain verified.