python3-rsa: Update to version 4.8 and python-3.10

python3-rsa: Update to version 4.8 and python-3.10

- Update from 4.0 to 4.8
- Update of rootfile
- Changelog
- Switch to [Poetry](https://python-poetry.org/) for dependency and release management.
- Compatibility with Python 3.10.
- Chain exceptions using `raise new_exception from old_exception`
  ([#157](https://github.com/sybrenstuvel/python-rsa/pull/157))
- Added marker file for PEP 561. This will allow type checking tools in dependent projects
  to use type annotations from Python-RSA
  ([#136](https://github.com/sybrenstuvel/python-rsa/pull/136)).
- Use the Chinese Remainder Theorem when decrypting with a private key. This
  makes decryption 2-4x faster
  ([#163](https://github.com/sybrenstuvel/python-rsa/pull/163)).
- Fix picking/unpickling issue introduced in 4.7
  ([#173](https://github.com/sybrenstuvel/python-rsa/issues/173))
- Fix threading issue introduced in 4.7
  ([#173](https://github.com/sybrenstuvel/python-rsa/issues/173))
- Fix [#165](https://github.com/sybrenstuvel/python-rsa/issues/165):
  CVE-2020-25658 - Bleichenbacher-style timing oracle in PKCS#1 v1.5 decryption
  code
- Add padding length check as described by PKCS#1 v1.5 (Fixes
  [#164](https://github.com/sybrenstuvel/python-rsa/issues/164))
- Reuse of blinding factors to speed up blinding operations.
  Fixes [#162](https://github.com/sybrenstuvel/python-rsa/issues/162).
- Declare & test support for Python 3.9
Version 4.4 and 4.6 are almost a re-tagged release of version 4.2. It requires
Python 3.5+. To avoid older Python installations from trying to upgrade to RSA
4.4, this is now made explicit in the `python_requires` argument in `setup.py`.
There was a mistake releasing 4.4 as "3.5+ only", which made it necessary to
retag 4.4 as 4.6 as well.
No functional changes compared to version 4.2.
Version 4.3 and 4.5 are almost a re-tagged release of version 4.0. It is the
last to support Python 2.7. This is now made explicit in the `python_requires`
argument in `setup.py`. Python 3.4 is not supported by this release. There was a
mistake releasing 4.4 as "3.5+ only", which made it necessary to retag 4.3 as
4.5 as well.
Two security fixes have also been backported, so 4.3 = 4.0 + these two fixes.
- Choose blinding factor relatively prime to N. Thanks Christian Heimes for pointing this out.
- Reject cyphertexts (when decrypting) and signatures (when verifying) that have
  been modified by prepending zero bytes. This resolves CVE-2020-13757. Thanks
  Carnil for pointing this out.
- Rolled back the switch to Poetry, and reverted back to using Pipenv + setup.py
  for dependency management. There apparently is an issue no-binary installs of
  packages build with Poetry. This fixes
  [#148](https://github.com/sybrenstuvel/python-rsa/issues/148)
- Limited SHA3 support to those Python versions (3.6+) that support it natively.
  The third-party library that adds support for this to Python 3.5 is a binary
  package, and thus breaks the pure-Python nature of Python-RSA.
  This should fix [#147](https://github.com/sybrenstuvel/python-rsa/issues/147).
- Added support for Python 3.8.
- Dropped support for Python 2 and 3.4.
- Added type annotations to the source code. This will make Python-RSA easier to use in
  your IDE, and allows better type checking.
- Added static type checking via [MyPy](http://mypy-lang.org/).
- Fix [#129](https://github.com/sybrenstuvel/python-rsa/issues/129) Installing from source
  gives UnicodeDecodeError.
- Switched to using [Poetry](https://poetry.eustace.io/) for package
  management.
- Added support for SHA3 hashing: SHA3-256, SHA3-384, SHA3-512. This
  is natively supported by Python 3.6+ and supported via a third-party
  library on Python 3.5.
- Choose blinding factor relatively prime to N. Thanks Christian Heimes for pointing this out.
- Reject cyphertexts (when decrypting) and signatures (when verifying) that have
  been modified by prepending zero bytes. This resolves CVE-2020-13757. Thanks
  Adelapie for pointing this out.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Reviewed-by: Peter Müller <peter.mueller@ipfire.org>