26 Commits

Author SHA1 Message Date
David Benjamin 4f0a7a7974 Update documentation on fuzzer mode
Noticed some things were out-of-date or confusing.

Change-Id: Ib71155fcaa5962aeff89a3ba00f1a1246ac79bff
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/89248
Commit-Queue: Lily Chen <chlily@google.com>
Auto-Submit: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Lily Chen <chlily@google.com>
2026-02-11 13:22:42 -08:00
David Benjamin 56383dabf4 Simplfy fuzzer build
Instead of having a pair of bespoke build definitions use the standard
FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION toggle. We actually originated
the idea of a fuzzing-specific build toggle, and then libFuzzer
standardized a toggle when we talked to them about what we were doing.

The problem is our fuzzer mode toggle substantially changed the TLS
stack behavior, such that downstream code would likely go haywire. So we
couldn't easily fold into the standard one, and all of BoringSSL's
downstream fuzzer builds were messy.

Instead, make a few changes:

1. Switch BORINGSSL_UNSAFE_DETERMINISTIC_MODE to
   FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION. That flag is not expected
   to cause downstream issues as it just makes the PRNG deterministic.

2. Replace BORINGSSL_UNSAFE_FUZZER_MODE with a runtime toggle that is
   only available when building with
   FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION.

3. Instead of the no_fuzzer_mode fuzzers being special corpora for the
   client and server fuzzers, they're now just separate fuzzerrs and
   follow the usual naming conventions between fuzzers and their
   corpora.

Update-Note: Downstream fuzzer builds can now be simplified. If the
fuzzing infrastructure already builds with
FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION, the separate boringssl_fuzz
(or whatever) target can be removed.

Bug: 42290128
Change-Id: Ia1e479777f366908951e15067c96c9767c229f0a
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/77749
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Bob Beck <bbe@google.com>
2025-03-20 03:41:54 -07:00
David Benjamin 51e517b22c Don't override the clock in BORINGSSL_UNSAFE_DETERMINISTIC_MODE
Instead, do it in a callback in the fuzzer itself. This removes a part
of BORINGSSL_UNSAFE_DETERMINISTIC_MODE that is probably a little tricky
to use automatically as FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION.

Bug: 42290128
Change-Id: Ie3a62e25b099b4cb4ca1c16581beb04fc9d9930e
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/77748
Commit-Queue: David Benjamin <davidben@google.com>
Auto-Submit: David Benjamin <davidben@google.com>
Reviewed-by: Bob Beck <bbe@google.com>
2025-03-19 23:58:30 -07:00
David Benjamin 1a5570b8e8 Update docs to recommend a much more convenient CMake invocation
Newer CMakes support a -B parameter, which saves some fuss.

Change-Id: Ifdbbb50b3720cdc42af098eb32941283692e9d99
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/58966
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Bob Beck <bbe@google.com>
Reviewed-by: Nabil Wadih <nwadih@google.com>
2023-04-19 20:16:58 +00:00
David Benjamin 5545b61a96 Use a consistent plural for 'corpus'.
'corpora' seems to be more common than 'corpuses' in Chromium code
search, including in libFuzzer's source itself.

Change-Id: I6489b57a4608f47274c4400aac135cbfb991953a
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/46825
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
2021-04-14 20:48:41 +00:00
Adam Langley 31f94b0bf7 List bn_div fuzzer in documentation.
c951e5560b added it back in the build, but it should be listed in
documentation too. Picked 384 bytes on the assumption that the largest
specialisation that we're likely to have is 1024-bit for RSA 2048.

Change-Id: I13fb46dceedb7a62616db6a2b39634a0b6fed508
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/38444
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2019-10-21 16:29:53 +00:00
Adam Langley 9c969bf491 Switch to Clang 6.0's fuzzer support.
With Clang 6.0, libFuzzer is now included and there's a new
-fsanitize=fuzzer command to enable the needed compiler actions.

Change-Id: If8c0d649f494655c5bb1e55ebdbf39450940c75b
Reviewed-on: https://boringssl-review.googlesource.com/31324
Reviewed-by: David Benjamin <davidben@google.com>
2018-08-27 17:18:56 +00:00
David Benjamin 13f1f17b43 Fix typo in FUZZING.md.
-shim-config, not -shim-path.

Change-Id: I338085b5b5b533f9d511e1b9d82dc44d1161bd26
Reviewed-on: https://boringssl-review.googlesource.com/17604
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-07-06 18:25:07 +00:00
David Benjamin 9343b0b8b3 Don't check renegotiation_info in fuzzer mode.
Otherwise the fuzzer gets stuck at renegotiations.

Bug: 104
Change-Id: If37f9ab165d06e37bfc5c423fba35edaabed293b
Reviewed-on: https://boringssl-review.googlesource.com/17532
Reviewed-by: David Benjamin <davidben@google.com>
2017-07-05 23:48:42 +00:00
David Benjamin 519118f984 Fix FUZZING.md typo.
Change-Id: Ie43ffabfdf5b10fbb0c8adcc2626a2913152e5e1
Reviewed-on: https://boringssl-review.googlesource.com/14525
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
2017-03-30 16:54:18 +00:00
David Benjamin 2ad3c989e8 Merge in upstream's certificate corpus.
This was done by running:

  ./fuzz/cert -merge=1 ../fuzz/cert_corpus ~/openssl/fuzz/corpora/x509

I bumped the max_len while doing so because some of those are rather
large.

Change-Id: Ic2caa09d5ff9ab05b46363940a91a03f270cbad8
Reviewed-on: https://boringssl-review.googlesource.com/12682
Reviewed-by: Adam Langley <agl@google.com>
2016-12-12 21:41:00 +00:00
Robert Sloan 15073af5b7 Adding a fuzzer for Sessions
Change-Id: I69cbb0679e1dbb6292a8f4737851736e58c17508
Reviewed-on: https://boringssl-review.googlesource.com/12481
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-12-01 20:22:56 +00:00
David Benjamin fd06601340 Add a script to refresh fuzzer corpora.
This is getting to be a nuisance to do by hand.

Change-Id: If3aa7c666c4cc0bf97615564f258ff740a561766
Reviewed-on: https://boringssl-review.googlesource.com/12281
Reviewed-by: David Benjamin <davidben@google.com>
2016-11-15 07:01:34 +00:00
David Benjamin ec978dd812 Add corpora for fuzzers with fuzzer mode disabled.
Fuzzer mode explores the handshake, but at the cost of losing coverage
on the record layer. Add a separate build flag and client/server
corpora for this mode.

Note this requires tweaks in consumers' fuzzer build definitions.

BUG=111

Change-Id: I1026dc7301645e165a761068a1daad6eedc9271e
Reviewed-on: https://boringssl-review.googlesource.com/12108
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
2016-11-09 16:53:37 +00:00
Adam Langley 3871dc9e39 Add a fuzzer for the SSL_CTX API.
This is not a complete fuzzer, even for SSL_CTX, but it's a start.

Written in memory of c-ares[1].

[1] https://twitter.com/hanno/status/781506296906444800

Change-Id: I64b02c60f35b9057201df2cc325ebb7a84a0229d
Reviewed-on: https://boringssl-review.googlesource.com/11423
Reviewed-by: Adam Langley <alangley@gmail.com>
Commit-Queue: Adam Langley <alangley@gmail.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-10-04 23:07:09 +00:00
David Benjamin fbc45d7228 No-op ticket encryption in fuzzer mode.
This allows the fuzzer to discover server-side resumption paths by
simply supplying what we'd like the ticket to decrypt to in the clear.
We also have a natural way to get transcripts out of runner. We record
the runner-side transcripts, so all resumption handshakes will replay
the shim-created unencrypted tickets.

BUG=104

Change-Id: Icf9cbf4af520077d38e2c8c2766b6f8bfa3c9ab5
Reviewed-on: https://boringssl-review.googlesource.com/11224
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-09-22 21:26:23 +00:00
David Benjamin 1e663e8f39 Document how to refresh the TLS corpora.
Change-Id: I9165357ca6c20b964ed13dc4e1f336c7b747033e
Reviewed-on: https://boringssl-review.googlesource.com/11223
Reviewed-by: Adam Langley <agl@google.com>
2016-09-22 21:18:16 +00:00
David Benjamin 01a905717c Fix remaining non-determinism in fuzzer transcripts.
Both the C and Go code were sampling the real clock. With this, two
successive iterations of runner transcripts give the same output.

Change-Id: I4d9e219e863881bf518c5ac199dce938a49cdfaa
Reviewed-on: https://boringssl-review.googlesource.com/11222
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-09-22 21:14:00 +00:00
Adam Langley d09175ffe3 Replace base64 decoding.
This code has caused a long history of problems. This change rewrites it
completely with something that is, hopefully, much simplier and robust
and adds more testing.

Change-Id: Ibeef51f9386afd95d5b73316e451eb3a2d7ec4e0
Reviewed-on: https://boringssl-review.googlesource.com/8033
Reviewed-by: Adam Langley <agl@google.com>
2016-05-26 17:59:10 +00:00
David Benjamin 1fc7564ba7 Add standalone PKCS#8 and SPKI fuzzers.
We already had coverage for our new EVP_PKEY parsers, but it's good to have
some that cover them directly. The initial corpus was generated manually with
der-ascii and should cover most of the insanity around EC key serialization.

BUG=15

Change-Id: I7aaf56876680bfd5a89f5e365c5052eee03ba862
Reviewed-on: https://boringssl-review.googlesource.com/7728
Reviewed-by: Adam Langley <agl@google.com>
2016-04-25 21:57:28 +00:00
Max Moroz 188487faad Remove .options files for libFuzzers and update FUZZING.md documentation.
Due to https://codereview.chromium.org/1867833002/ replacing .options files.

Change-Id: I17f0d5b8b1784fdcf163791e72f6b58b29657e95
Reviewed-on: https://boringssl-review.googlesource.com/7640
Reviewed-by: David Benjamin <davidben@google.com>
2016-04-12 14:56:57 +00:00
David Benjamin 9539ebbf70 Update FUZZING documentation about max_len.
Maintain the max_len values in foo.options files which ClusterFuzz can process.
Also recompute the recommended client and server lengths as they've since
gotten much more extensive.

Change-Id: Ie87a80d8a4a0c41e215f0537c8ccf82b38c4de09
Reviewed-on: https://boringssl-review.googlesource.com/7509
Reviewed-by: Mike Aizatsky <aizatsky@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-22 18:46:35 +00:00
David Benjamin e11988f511 Tweak FUZZING.md and minimise_corpuses.sh.
Change-Id: If312ce3783bcc39ebd2047470251334aa0897d3d
Reviewed-on: https://boringssl-review.googlesource.com/7508
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-21 20:23:15 +00:00
Adam Langley ddcc186ef1 Document how to minimise corpuses.
Change-Id: Ie487163787d78d867e34709fb34b4c6a836f668d
Reviewed-on: https://boringssl-review.googlesource.com/7275
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-03 18:05:34 +00:00
Adam Langley 7104cc96b7 Update and fix fuzzing instructions.
It's easier to put libFuzzer.a into the source directory than to install
it globally.

Change-Id: I4dc7b56f81c7aa0371475c68d23368b025186505
Reviewed-on: https://boringssl-review.googlesource.com/6461
Reviewed-by: Adam Langley <agl@google.com>
2015-11-10 23:37:36 +00:00
Adam Langley 9a4beb8ad8 Add four, basic fuzz tests.
This change adds fuzzing tests for:
  ∙ Certificate parsing
  ∙ Private key parsing
  ∙ ClientHello parsing
  ∙ Server first flow (ServerHello, Certificate, etc) parsing.

Change-Id: I5f53282263eaaff69b1a03c819cca73750433653
Reviewed-on: https://boringssl-review.googlesource.com/6460
Reviewed-by: Adam Langley <agl@google.com>
2015-11-10 19:14:01 +00:00