The `pki.decryptRsaPrivateKey` function can return null if the password is wrong

[CMCDragonkai]

The types for pki.decryptRsaPrivateKey indicates that it will always return a rsa.PrivateKey. However if the password is wrong, it will sometimes throw an error, and sometimes return a null.

The null is not indicated by the type signature at all. This threw off me quite a bit, because this is random behaviour as it depends on the generated key as well. The exact exception being thrown is also random.

[khoek]

This tripped me up, too

[denirun]

I agree, has the same problem. My password contains "$" sign... and result is null. This problem need to be fixed.