|author||David Benjamin <email@example.com>||Thu Oct 03 17:35:52 2019 -0400|
|committer||CQ bot account: firstname.lastname@example.org <email@example.com>||Thu Oct 03 22:10:36 2019 +0000|
Add .note.GNU-stack at the source level. GNU-based toolchains on ELF platforms default the stack to executable and rely on a .note.GNU-stack section in *each* object file to flip it off. The compiler knows to do this for its object files, but assembly does everything by hand. See this link for details: https://www.airs.com/blog/archives/518 We do this in the cmake build by passing -Wa,--noexecstack to the assembler. However, since we have to deal with many buildsystems, it would be more robust to put it in the source. It's unclear whether this should be gated on ELF or Linux. The Gentoo and Ubuntu documents recommend checking for Linux with gas, but only ELF with NASM. https://wiki.gentoo.org/wiki/Hardened/GNU_stack_quickstart https://wiki.ubuntu.com/SecurityTeam/Roadmap/ExecutableStacks At the same time, these links suggest it is an ELF-wide issue and not just Linux: https://github.com/golang/go/issues/5392 https://reviews.freebsd.org/D11033 https://github.com/openssl/openssl/issues/4575 also discusses this but the rationale lists both ELF and non-ELF platforms, so it's unclear. Treat it as ELF-wide for now. We can revisit this if necessary. Update-Note: If there is a build failure due to .note.GNU-stack, holler. Change-Id: Ic59096aa1fc2bf5380a412c9991de22cb46c0faf Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/37984 Reviewed-by: Adam Langley <firstname.lastname@example.org> Commit-Queue: David Benjamin <email@example.com>
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.
There are other files in this directory which might be helpful: