Missing algorithms

[qmuntal]

This issue lists the algorithms that are implemented in dev.boringbranch by BoringSSL but not available in Windows CNG.

• SHA methods don't implement BinaryMarshaller and BinaryUnmarshaller interfaces. I still haven't found a way to get the inner state of the SHAs and map it to Go binary representation.
• SHA224.
• MD5SHA1
• AES and DES CTR mode. We might be able to implement it using AES in ECB mode and some custom logic: https://gist.github.com/hanswolff/8809275. Another option is to fallback to Go Crypto.
• rsa.PSSSaltLengthAuto
• RSA keys with more than 2 primes
• RSA key lengths are more restrictive, i.e. must be bigger or equal than 512 and multiple of 8.
• dsa.L2048N224

[qmuntal]

The crypto api team said that we can use BCRYPT_RSAFULLPRIVATE_BLOB even when running on FIPS mode. It's up to the caller to keep it safe.