boringssl/ssl/test
David Benjamin 17d553d299 Add a CFI tester to CHECK_ABI.
This uses the x86 trap flag and libunwind to test CFI works at each
instruction. For now, it just uses the system one out of pkg-config and
disables unwind tests if unavailable. We'll probably want to stick a
copy into //third_party and perhaps try the LLVM one later.

This tester caught two bugs in P-256 CFI annotations already:
I47b5f9798b3bcee1748e537b21c173d312a14b42 and
I9f576d868850312d6c14d1386f8fbfa85021b347

An earlier design used PTRACE_SINGLESTEP with libunwind's remote
unwinding features. ptrace is a mess around stop signals (see group-stop
discussion in ptrace(2)) and this is 10x faster, so I went with it. The
question of which is more future-proof is complex:

- There are two libunwinds with the same API,
  https://www.nongnu.org/libunwind/ and LLVM's. This currently uses the
  system nongnu.org for convenience. In future, LLVM's should be easier
  to bundle (less complex build) and appears to even support Windows,
  but I haven't tested this.  Moreover, setting the trap flag keeps the
  test single-process, which is less complex on Windows. That suggests
  the trap flag design and switching to LLVM later. However...

- Not all architectures have a trap flag settable by userspace. As far
  as I can tell, ARMv8's PSTATE.SS can only be set from the kernel. If
  we stick with nongnu.org libunwind, we can use PTRACE_SINGLESTEP and
  remote unwinding. Or we implement it for LLVM. Another thought is for
  the ptracer to bounce SIGTRAP back into the process, to share the
  local unwinding code.

- ARMv7 has no trap flag at all and PTRACE_SINGLESTEP fails. Debuggers
  single-step by injecting breakpoints instead. However, ARMv8's trap
  flag seems to work in both AArch32 and AArch64 modes, so we may be
  able to condition it on a 64-bit kernel.

Sadly, neither strategy works with Intel SDE. Adding flags to cpucap
vectors as we do with ARM would help, but it would not emulate CPUs
newer than the host CPU. For now, I've just had SDE tests disable these.

Annoyingly, CMake does not allow object libraries to have dependencies,
so make test_support a proper static library. Rename the target to
test_support_lib to avoid
https://gitlab.kitware.com/cmake/cmake/issues/17785

Update-Note: This adds a new optional test dependency, but it's disabled
by default (define BORINGSSL_HAVE_LIBUNWIND), so consumers do not need
to do anything. We'll probably want to adjust this in the future.

Bug: 181
Change-Id: I817263d7907aff0904a9cee83f8b26747262cc0c
Reviewed-on: https://boringssl-review.googlesource.com/c/33966
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
2019-01-03 22:01:55 +00:00
..
runner Add |SSL_key_update|. 2018-12-19 20:15:24 +00:00
async_bio.cc
async_bio.h
bssl_shim.cc Add |SSL_key_update|. 2018-12-19 20:15:24 +00:00
CMakeLists.txt Add a CFI tester to CHECK_ABI. 2019-01-03 22:01:55 +00:00
fuzzer_tags.h Fuzz SSL_serialize_handoff() and SSL_serialize_handback(). 2018-05-05 02:41:04 +00:00
fuzzer.h Remove SSL 3.0 implementation. 2018-06-28 16:54:58 +00:00
handshake_util.cc shim: don't clear environment when invoking handshaker. 2018-08-28 17:50:26 +00:00
handshake_util.h shim: perform split handshakes in a separate binary. 2018-08-01 01:44:53 +00:00
handshaker.cc handshaker: kick PRNG when resuming in UNSAFE_DETERMINISTIC_MODE. 2018-08-03 23:11:46 +00:00
packeted_bio.cc Remove support for blocking DTLS timeout handling. 2017-03-01 19:59:28 +00:00
packeted_bio.h Remove support for blocking DTLS timeout handling. 2017-03-01 19:59:28 +00:00
PORTING.md Document that malloc tests require a longer timeout. 2016-09-30 19:13:05 +00:00
README.md
settings_writer.cc shim: move |SettingsWriter| into its own file. 2018-07-02 22:26:28 +00:00
settings_writer.h shim: move |SettingsWriter| into its own file. 2018-07-02 22:26:28 +00:00
test_config.cc Add |SSL_key_update|. 2018-12-19 20:15:24 +00:00
test_config.h Add |SSL_key_update|. 2018-12-19 20:15:24 +00:00
test_state.cc shim: perform split handshakes in a separate binary. 2018-08-01 01:44:53 +00:00
test_state.h shim: perform split handshakes in a separate binary. 2018-08-01 01:44:53 +00:00

BoringSSL SSL Tests

This directory contains BoringSSL's protocol-level test suite.

Testing a TLS implementation can be difficult. We need to produce invalid but sufficiently correct handshakes to get our implementation close to its edge cases. TLS's cryptographic steps mean we cannot use a transcript and effectively need a TLS implementation on the other end. But we do not wish to litter BoringSSL with options for bugs to test against.

Instead, we use a fork of the Go crypto/tls package, heavily patched with configurable bugs. This code, along with a test suite and harness written in Go, lives in the runner directory. The harness runs BoringSSL via a C/C++ shim binary which lives in this directory. All communication with the shim binary occurs with command-line flags, sockets, and standard I/O.

This strategy also ensures we always test against a second implementation. All features should be implemented twice, once in C for BoringSSL and once in Go for testing. If possible, the Go code should be suitable for potentially upstreaming. However, sometimes test code has different needs. For example, our test DTLS code enforces strict ordering on sequence numbers and has controlled packet drop simulation.

To run the tests manually, run go test from the runner directory. It takes command-line flags found at the top of runner/runner.go. The -help option also works after using go test -c to make a runner.test binary first.

If adding a new test, these files may be a good starting point:

  • runner/runner.go: the test harness and all the individual tests.
  • runner/common.go: contains the Config and ProtocolBugs struct which control the Go TLS implementation's behavior.
  • test_config.h, test_config.cc: the command-line flags which control the shim's behavior.
  • bssl_shim.cc: the shim binary itself.

For porting the test suite to a different implementation see PORTING.md.