Replaces our built-in SHA3 implementation with a verified one from the HACL* project.
This implementation is used when OpenSSL does not provide SHA3 or is not present.
3.11 shiped with a very slow tiny sha3 implementation to get off of the <=3.10 reference implementation that wound up having serious bugs. This brings us back to a reasonably performing built-in implementation consistent with what we've just replaced our other guaranteed available standard hash algorithms with: code from the HACL* project.
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Co-authored-by: Gregory P. Smith <greg@krypto.org>
Replace the builtin hashlib implementations of SHA2-384 and SHA2-512
originally from LibTomCrypt with formally verified, side-channel resistant
code from the [HACL*](https://github.com/hacl-star/hacl-star/) project.
The builtins remain a fallback only used when OpenSSL does not provide them.
replacing hashlib primitives (for the non-OpenSSL case) with verified implementations from HACL*. This is the first PR in the series, and focuses specifically on SHA2-256 and SHA2-224.
This PR imports Hacl_Streaming_SHA2 into the Python tree. This is the HACL* implementation of SHA2, which combines a core implementation of SHA2 along with a layer of buffer management that allows updating the digest with any number of bytes. This supersedes the previous implementation in the tree.
@franziskuskiefer was kind enough to benchmark the changes: in addition to being verified (thus providing significant safety and security improvements), this implementation also provides a sizeable performance boost!
```
---------------------------------------------------------------
Benchmark Time CPU Iterations
---------------------------------------------------------------
Sha2_256_Streaming 3163 ns 3160 ns 219353 // this PR
LibTomCrypt_Sha2_256 5057 ns 5056 ns 136234 // library used by Python currently
```
The changes in this PR are as follows:
- import the subset of HACL* that covers SHA2-256/224 into `Modules/_hacl`
- rewire sha256module.c to use the HACL* implementation
Co-authored-by: Gregory P. Smith [Google LLC] <greg@krypto.org>
Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>
Jonathan Protzenko