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

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

Change-Id: I5bb53e068d5900daca07299a27c0551e78ffa91d
Commit-Queue: David Benjamin <>
Reviewed-by: Adam Langley <>
3 files changed
tree: 1ab85c5443cfbaf5fab9c8abfab238b6e6e2d7ae
  1. .github/
  2. crypto/
  3. decrepit/
  4. fuzz/
  5. include/
  6. ssl/
  7. third_party/
  8. tool/
  9. util/
  10. .clang-format
  11. .gitignore
  15. CMakeLists.txt
  16. codereview.settings
  19. go.mod
  20. go.sum
  26. sources.cmake


BoringSSL is a fork of OpenSSL that is designed to meet Google's needs.

Although BoringSSL is an open source project, it is not intended for general use, as OpenSSL is. We don't recommend that third parties depend upon it. Doing so is likely to be frustrating because there are no guarantees of API or ABI stability.

Programs ship their own copies of BoringSSL when they use it and we update everything as needed when deciding to make API changes. This allows us to mostly avoid compromises in the name of compatibility. It works for us, but it may not work for you.

BoringSSL arose because Google used OpenSSL for many years in various ways and, over time, built up a large number of patches that were maintained while tracking upstream OpenSSL. As Google's product portfolio became more complex, more copies of OpenSSL sprung up and the effort involved in maintaining all these patches in multiple places was growing steadily.

Currently BoringSSL is the SSL library in Chrome/Chromium, Android (but it's not part of the NDK) and a number of other apps/programs.

Project links:

There are other files in this directory which might be helpful: