| commit | 9580424ca8579317d0ccf1d8db5e58539f239a20 | [log] [tgz] |
|---|---|---|
| author | David Benjamin <davidben@google.com> | Thu Feb 09 15:51:35 2023 -0500 |
| committer | Boringssl LUCI CQ <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com> | Thu Feb 09 22:19:14 2023 +0000 |
| tree | 45d6759322fb215ac11a70d46bea0d09c98b6118 | |
| parent | 8846d7b3c35745f5ecc053f650dd76d3750d7ce5 [diff] |
Bound the overall output size of ASN1_generate_v3 The output of ASN1_generate_v3 is *mostly* linear with the input, except SEQ and SET reference config sections. Sections can be referenced multiple times, and so the structure grows exponentially. Cap the total output size to mitigate this. As before, we don't consider these functions safe to use with untrusted inputs, but unbounded growth will frustrate fuzzing. This CL sets the limit to 64K, which should be enough for anyone. (This is the size of a single X.509 extension, whereas certificates themselves should not get that large.) While not strictly necessary, this also rearranges the ASN1_mbstring_copy call to pass in a maximum output. This portion does scale linearly with the output, so it's fine, but the fuzzer discovered an input with a 700K-byte input, which, with fuzzer instrumentation and sanitizers, seems to be a bit slow. This change should help the fuzzer get past those cases faster. Update-Note: The stringly-typed API for constructing X.509 extensions now has a maximum output size. If anyone was constructing an extension larger than 64K, this will break. This is unlikely and should be caught by unit tests; if a project hits this outside of tests, that means they are passing untrusted input into this function, which is a security vulnerability in itself, and means they especially need this change to avoid a DoS. Bug: oss-fuzz:55725 Change-Id: Ibb65854293f44bf48ed5855016ef7cd46d2fae77 Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/57125 Reviewed-by: Bob Beck <bbe@google.com> Commit-Queue: David Benjamin <davidben@google.com> Auto-Submit: David Benjamin <davidben@google.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.
Project links:
There are other files in this directory which might be helpful: