Memoize precomputed objects for multiple subsequent uses

[lavafroth]

Changes

• The hashes and digests are calculated only once for use in subsequent statements.
• The nullish or operator is used when a decryption function returns None to lazily evaluate the next decryption alternative.

[zblurx]

Hey, nice PR. Can you update python dependency to 3.8 in pyproject.toml since you set some := operator ?

[lavafroth]

Should be ready for the merge now!

[zblurx]

Finally I have a problem with python3.8 for now : NetExec use dploot for the --dpapi functionnality, but the project is supposed to work on python 3.7. So either way we wait for NetExec to upgrade a bit, or we change the := operator.

[lavafroth]

I have reverted the python version and the walrus operator, should be good to go now.

[zblurx]

Great thank you !!