RFR: 8320597: RSA signature verification fails on signed data that does not encode params correctly

[Weijun Wang]

Add a fallback if an RSA signature was generated without the NULL params in its encoded hash.

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Commit messages:
 - chmod
 - the fix

Changes: https://git.openjdk.org/jdk/pull/17002/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17002&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8320597
  Stats: 88 lines in 3 files changed: 65 ins; 13 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/17002.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17002/head:pull/17002

PR: https://git.openjdk.org/jdk/pull/17002