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>
David Benjamin
Adam Langley