The usedforsecurity keyword only argument added to the hash constructors is useful for FIPS builds and similar restrictive environment with non-technical requirements that legacy algorithms be forbidden by their implementations without being explicitly annotated as not being used for any security related purposes. Linux distros with FIPS support benefit from this being standard rather than making up their own way(s) to do it.
Contributed and Signed-off-by: Christian Heimes christian@python.org
* help(hashlib) didn't work because of incorrect module name in blake2b and
blake2s classes.
* Constructors blake2*(), sha3_*(), shake_*() and keccak_*() incorrectly
accepted keyword argument "string" for binary data, but documented as
accepting the "data" keyword argument. Now this parameter is positional-only.
* Keyword-only parameters in blake2b() and blake2s() were not documented as
keyword-only.
* Default value for some parameters of blake2b() and blake2s() was None,
which is not acceptable value.
* The length argument for shake_*.digest() was wrapped out to 32 bits.
* The argument for shake_128.digest() and shake_128.hexdigest() was not
positional-only as intended.
* TypeError messages for incorrect arguments in all constructors sha3_*(),
shake_*() and keccak_*() incorrectly referred to sha3_224.
Also made the following enhancements:
* More accurately specified input and result types for strings, bytes and
bytes-like objects.
* Unified positional parameter names for update() and constructors.
* Improved formatting.
Christian Heimes
Serhiy Storchaka
Victor Stinner
Benjamin Peterson