tree e91ad0942a47e826d91d8d6d6177868970cfaf22
parent e9f816b12b3e68de575d21e2a9b7d76e4e5c58ac
author David Benjamin <davidben@google.com> 1690143511 -0700
committer Boringssl LUCI CQ <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com> 1690218121 +0000

Use a stub fopen implementation when OPENSSL_NO_FILESYSTEM is set

Detecting errors (i.e. fs-less platforms using fs-only APIs) at compile
time is generally preferable to doing so at runtime, so
https://boringssl-review.googlesource.com/c/boringssl/+/61726 opted to
remove the APIs altogether on applicable targets.

However, Trusty uses rust-openssl somewhere and rust-openssl binds a
bunch of filesystem-dependent APIs unconditionally. To keep that
working, switch to a stub fopen when OPENSSL_NO_FILESYSTEM is set. We
effectively model a platform where the filesystem "exists", but is
empty. Upstream OpenSSL similarly has OPENSSL_NO_STDIO still define the
file BIO (unlike the socket BIO, which is excluded), but in a stub form.

As part of this, I've gone ahead and resolved one of the Trusty TODOs.
It does produce a duplicate symbol with [1], but things seem to link
fine in treehugger. In case it does break, I've bumped
BORINGSSL_API_VERSION, so we can go in and condition it if needed.

[1] https://android.googlesource.com/trusty/lib/+/refs/heads/main/lib/openssl-stubs/bio.c

Bug: 629
Change-Id: I4f20d872a7cde863d21c78090f270b77b03545fa
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/61925
Commit-Queue: Bob Beck <bbe@google.com>
Auto-Submit: David Benjamin <davidben@google.com>
Reviewed-by: Bob Beck <bbe@google.com>