build(deps): bump rsa from 4.2 to 4.7 in /backend

[dependabot]

Bumps rsa from 4.2 to 4.7.

Changelog

Sourced from rsa's changelog.

Version 4.7 - released 2021-01-10

• Fix #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)
• Reuse of blinding factors to speed up blinding operations. Fixes #162.
• Declare & test support for Python 3.9

Version 4.4 & 4.6 - released 2020-06-12

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 & 4.5 - released 2020-06-12

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.

Commits

• fa3282a Bumped version to 4.7
• a364e82 Marked version 4.7 as released
• 539c54a Fix #170: mistake in examples of documentation
• b81e317 Declare support for and test Python 3.9
• 06ec1ea Fix #162: Blinding uses slow algorithm
• 341e5c4 Directly raise DecryptionError when crypto length is bad
• f254895 Use bytes.find() instead of bytes.index()
• 240b0d8 Add link to changelog
• f878c37 Fix #164: Add padding length check as described by PKCS#1 v1.5
• dae8ce0 Fix #165: CVE-2020-25658 - Bleichenbacher-style timing oracle
• Additional commits viewable in compare view

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[MasterKenth]

@dependabot recreate