[Fix] sign/verify generic SHA algorithms with RSA keys

[puneetdixit200]

Summary

• allow generic SHA algorithms to sign and verify RSA keys by using the same PKCS#1 DigestInfo tags as the RSA-named aliases
• add Node parity coverage for sha224, sha256, sha384, and sha512 with RSA keys

Fixes #84

Verification

• npm_config_cache=/tmp/browserify-sign-84-npm-cache npx tape test/index.js (red before fix: wrong private key type; green after fix: 629/629)
• npm_config_cache=/tmp/browserify-sign-84-npm-cache npm run lint (exit 0; existing warnings only)
• npm_config_cache=/tmp/browserify-sign-84-npm-cache npm run tests-only (629/629, 100% coverage)
• git diff --check
• npm_config_cache=/tmp/browserify-sign-84-npm-cache npm test (exit 0; audit reports existing low elliptic advisory with no fix available)

[ljharb]

Thanks - just to clarify, are you Puneet Dixit or Deepak Kudi? Your commit has an author with a different name that's not linked to a github account.

[ljharb]

LGTM once the commit authorship is cleared up

[ljharb]

@puneetdixit200 that's fine, but can you explain the discrepancy?

[puneetdixit200]

The mismatch came from an old local git identity on my machine. I amended the commit so the current author and committer are both Puneet Dixit <236133619+puneetdixit200@users.noreply.github.com>, and GitHub links the commit to this account now.