96b05ed487
It's not clear that CPUID will always report the correct value here,
especially for hyper-threading environments. It also isn't clear that
the assumptions made by AMD processors are correct and will always be
correct. It also seems likely that, if a code path is
security-sensitive w.r.t. SMT, it is probably also security-sensitive
w.r.t. other processor (mis)features. Finally, it isn't clear that all
dynamic analysis (fuzzing, SDE, etc.) is done separately for the cross
product of all CPU feature combinations * the value of this bit.
With all that in mind, instruct code sensitive to this bit to always
choose the more conservative path.
I only found one place that's sensitive to this bit, though I didn't
look too hard:
```
aes_nohw_cbc_encrypt:
[...]
leaq OPENSSL_ia32cap_P(%rip),%r10
mov (%r10), %r10d
[...]
bt \$28,%r10d
jc .Lcbc_slow_prologue
```
I didn't verify that the code in the HTT-enabled paths is any better
than the code in the HTT-disabled paths.
Change-Id: Ifd643e6a1301e5ca2174b84c344eb933d49e0067
Reviewed-on: https://boringssl-review.googlesource.com/c/33404
Reviewed-by: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
|
||
|---|---|---|
| .github | ||
| crypto | ||
| decrepit | ||
| fipstools | ||
| fuzz | ||
| include/openssl | ||
| infra/config | ||
| ssl | ||
| third_party | ||
| tool | ||
| util | ||
| .clang-format | ||
| .gitignore | ||
| API-CONVENTIONS.md | ||
| BREAKING-CHANGES.md | ||
| BUILDING.md | ||
| CMakeLists.txt | ||
| codereview.settings | ||
| CONTRIBUTING.md | ||
| FUZZING.md | ||
| go.mod | ||
| INCORPORATING.md | ||
| LICENSE | ||
| PORTING.md | ||
| README.md | ||
| sources.cmake | ||
| STYLE.md | ||
BoringSSL
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:
- PORTING.md: how to port OpenSSL-using code to BoringSSL.
- BUILDING.md: how to build BoringSSL
- INCORPORATING.md: how to incorporate BoringSSL into a project.
- API-CONVENTIONS.md: general API conventions for BoringSSL consumers and developers.
- STYLE.md: rules and guidelines for coding style.
- include/openssl: public headers with API documentation in comments. Also available online.
- FUZZING.md: information about fuzzing BoringSSL.
- CONTRIBUTING.md: how to contribute to BoringSSL.
- BREAKING-CHANGES.md: notes on potentially-breaking changes.