Why does HMACStrategy.Generate uses a lock?

mitar commented 8 months ago

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Ory Network Project

No response

Describe the bug

While reading the code, I noticed that HMACStrategy.Generate uses a mutex lock, but I do not get why it exists. No code there has any global or local state?

This was introduced in https://github.com/ory/fosite/commit/b4b9be5640c9d814b35f54b2c8621137364209ca, but I also do not get why.

Given that this is used a lot, I think mutex could be removed?

Reproducing the bug

N/A

Relevant log output

No response

Relevant configuration

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Version

latest master

On which operating system are you observing this issue?

None

In which environment are you deploying?

None

Additional Context

No response

james-d-elliott commented 8 months ago

I suspect it may have been implemented at a time where there was a lot of information about it being unsafe for concurrent usage, which I believe from memory was false and it was based on a couple articles from prominent bloggers who misinterpreted the issues with math/rand's global Read func instead of crypto/rand's global Reader.

But I can't say for sure.

mitar commented 8 months ago

You mean RandomBytes? But then the lock could be in RandomBytes?

james-d-elliott commented 8 months ago

Yeah I'm not sure, I would have thought so too.. I can't see anything else unless the crypto module being used at the time needed it.

ory / fosite