Linux module signing uses PKCS#7 / CMS because everything is awful and
broken. In order to make the lives of kernel developers easier, support
the calling pattern that the kernel uses to sign modules.
The kernel utility was written at a time when PKCS#7 was hard coded to
use SHA-1 for signing in OpenSSL and it reflects this: you can only
specify “sha1” on the command line, for example. As of OpenSSL 1.1.1, at
least, OpenSSL uses SHA-256 and thus so does this change.
Change-Id: I32b036123a0d8b272ec9e1c0130c45bf3ed0d2c7
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/49545
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
PKCS#7 stores certificates and CRLs in (implicitly-tagged) SET OF
types. This means they're unordered and, in DER, must be sorted.
We currently sort neither. OpenSSL upstream sorts CRLs but doesn't sort
certificates. https://github.com/openssl/openssl/pull/13143 reports that
Microsoft has a stricter parser that checks this. This CL fixes both
fields in our serializer.
This does not change the parsing code, which still preserves whatever
order we happened to find, but I've updated the documentation to clarify
that callers should not rely on the ordering.
Based on [0] and the odd order in kPKCS7NSS, I believe this aligns with
NSS's behavior.
Update-Note: It is no longer the case that constructing a PKCS#7 file
and parsing them back out will keep the certificates and CRLs in the
same order.
[0] https://source.chromium.org/chromium/chromium/src/+/main:chrome/common/net/x509_certificate_model_nss_unittest.cc;drc=c91b0c37b5ddf31cffd732c661c0c5930b0740f4;l=286
Change-Id: If776bb78476557af2c4598f1b6dc10e189adab5d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/47304
Reviewed-by: Adam Langley <agl@google.com>
Adam Langley
David Benjamin