tree 1ab85c5443cfbaf5fab9c8abfab238b6e6e2d7ae
parent 2f3958a4156d95c7e9778979acda4e43c7d15979
author David Benjamin <davidben@google.com> 1618601476 -0400
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> 1618604115 +0000

Always encode booleans as DER.

The ASN1_BOOLEAN representation is a mess. ASN1_BOOLEAN is an int
and if non-negative (negative values mean omitted or default), gets cast
to uint8_t and encoded as the value. This means callers are simply
expected to know true is 0xff, not 1. Fix this by only encoding 0 or
0xff.

This also fixes a bug where values like 0x100 are interpreted as true
(e.g. in the tasn_enc.c logic to handle default values), but encoded as
false because the cast only looks at the least significant byte.

This CL does not change the parsing behavior, which is to allow any BER
encoding and preserve the value in the in-memory representation (though
we should tighten that). However the BER encode will no longer be
preserved when re-encoding.

Update-Note: Callers setting ASN1_BOOLEANs to a positive value other
than 0xff will now encode 0xff. This probably fixes a bug, but if anyone
was attaching significance to incorrectly-encoded booleans, that will
break.

Change-Id: I5bb53e068d5900daca07299a27c0551e78ffa91d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/46924
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>