security/py-pycryptodome: Update to 3.8.1

While I'm here:

• Level up port compliance (strip additional shared libraries in subdirectory PublicKey/)

Changelog since 3.7.3:

New features

• Add support for loading PEM files encrypted with AES192-CBC, AES256-CBC and AES256-GCM.
• When importing ECC keys, ignore EC PARAMS section that was included by some openssl commands.
• Speed-up ECC performance. ECDSA is 33 times faster on the NIST P-256 curve
• Added support for NIST P-384 and P-521 curves.
• EccKey has new methods size_in_bits() and size_in_bytes().
• Support HMAC-SHA224, HMAC-SHA256, HMAC-SHA384, and HMAC-SHA512 in PBE2/PBKDF2.

Resolved issues

• repr() did not work for ECC.EccKey.
• Fix installation in development mode.
• Minimal length for Blowfish cipher is 32 bits, not 40 bits.
• Various updates to docs.
• DER objects were not rejected if their length field had a leading zero.
• Allow legacy RC2 ciphers to have 40-bit keys.
• ASN.1 Object IDs did not allow the value 0 in the path.

Breaks in compatibility

• point_at_infinity() becomes an instance method for Crypto.PublicKey.ECC.EccKey, from a static one.

https://www.pycryptodome.org/en/latest/src/changelog.html#april-2019

PR: 237696
Submitted by: John W. O'Brien <john@saltant.com> (maintainer)
Approved by: mentors (implicit)