tree 14d9aaef0b5cc8bb15ccb3c6c6cd85084c38ae8a
parent 38890fdef40e3491ce93124825ebea2e63ef2328
author David Benjamin <davidben@google.com> 1633186644 -0400
committer Adam Langley <agl@google.com> 1633456597 +0000

Make ASN1_STRING_TABLE_add thread-safe and document.

This function is a little awkward. It mutates global data, so if two
libraries in the address space both attempt to define a custom OID, they
will conflict. But some existing code uses it so, as long as it does so,
we should make it thread-safe.

Along the way, I've switched it to a hash table and removed the ability
to overwrite existing entries. Previously, overwriting a built-in table
would crash (on platforms where const structures are write-protected).
Overwriting a dynamic table implemented this weird merging algorithm.
The one caller I've seen does not appear to need this feature.

I've also switched ASN1_STRING_TABLE_cleanup to a no-op, matching our
other global cleanup functions. This function is not safe to call
without global knowledge of all other uses of the library.

Update-Note: ASN1_STRING_TABLE_add no longer allows overwrite existing
entries. In most cases, this would crash or trigger a race condition
anyway.

Bug: 426
Change-Id: Ie024cca87feaef3ff10064b452f3a860844544da
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/49769
Reviewed-by: Adam Langley <agl@google.com>