The OpenSSL X.509 verifier lacks a proper path builder. When there are
two paths available for a certificate, we pick one without looking at
expiry, etc.
In scenarios like one below, X509_V_FLAG_TRUSTED_FIRST will prefer
Leaf -> Intermediate -> Root1. Otherwise, we will prefer
Leaf -> Intermediate -> Root1Cross -> Root2:
Root2
|
Root1 Root1Cross
\ /
Intermediate
|
Leaf
If Root2 is expired, as with Let's Encrypt, X509_V_FLAG_TRUSTED_FIRST
will find the path we want. Same if Root1Cross is expired. (Meanwhile,
if Root1 is expired, TRUSTED_FIRST will break and leaving it off works.
TRUSTED_FIRST does not actually select chains with validity in mind. It
just changes the semi-arbitrary decision.)
OpenSSL 1.1.x now defaults to X509_V_FLAG_TRUSTED_FIRST by default, so
match them. Hopefully the shorter chain is more likely to be correct.
Update-Note: X509_verify_cert will now build slightly different chains
by default. Hopefully, this fixes more issues than it causes, but there
is a risk of trusted_first breaking other scenarios. Those scenarios
will also break OpenSSL 1.1.x defaults, so hopefully this is fine.
Bug: 439
Change-Id: Ie624f1f7e85a9e8c283f1caf24729aef9206ea16
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/49746
Reviewed-by: Adam Langley <agl@google.com>
Reviewed-by: Ryan Sleevi <rsleevi@chromium.org>
This is a bit short of a name to take, and no one seems to be using
it. (OpenSSL has renamed it, but not unexported it.)
Change-Id: I0de74d4d4812678ac3b1ec4b1b126a7748fe952b
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/48129
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
See also upstream's 9689a6aeed4ef7a2357cb95191b4313175440e4c.
X509_VERIFY_PARAM_ID made sense as a separate structure when
X509_VERIFY_PARAM was public, but now the struct is unexported.
Change-Id: I93bac64d33b76aa020fae07bba71b04f1505fdc4
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/48128
Reviewed-by: Adam Langley <agl@google.com>
David Benjamin
Adam Langley