RFC 2315 Section 9.3 describes the message digesting process. The
digest calculated depends on whether the authenticated attributes are
present. In case of a scenario where the authenticated attributes are
present, the message digest that gets signed and is part of the pkcs7
message is computed from the auth attributes rather than the contents
field.
Check if the auth attributes are present, and if set, use the auth
attributes to compute the hash that would be compared with the
encrypted hash on the pkcs7 message.
Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
The function, pkcs7_verify_one(), will be utilized to rework signature
verification logic aiming to support intermediate certificates in
"chain of trust."
To do that, its function interface is expanded, adding an extra argument
which is expected to return the last certificate in trusted chain.
Then, this last one must further be verified with signature database, db
and/or dbx.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
This function was nullified when the file, pkcs7_verify.c, was imported
because it calls further linux-specific interfaces inside, hence that
could lead to more files being imported from linux.
We need this function in pkcs7_verify_one() and so simply re-implement it
here instead of re-using the code.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
The file, pkcs7_verify.c, will now be imported from linux code
(crypto/asymmetric_keys/pkcs7_verify.c in 5.7) and modified to fit
into U-Boot environment.
In particular, pkcs7_verify_one() function will be used in a later patch
to rework signature verification logic aiming to support intermediate
certificates in "chain of trust."
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
