Add support for RSASSA-PSS (PS256) algorithm

[randilt]

Purpose

Fixes #8292

This PR implements RSASSA-PSS (PS256) signature support for the Ballerina crypto library, addressing the current limitation where only classic RSA signatures (PKCS#1 v1.5) are available.

Examples

Sign data

crypto:PrivateKey privateKey = check crypto:decodeRsaPrivateKeyFromKeyStore(keyStore, "keyAlias", "keyPassword");
byte[] signature = check crypto:signRsaSsaPss256(data, privateKey);

Verify signature

crypto:PublicKey publicKey = check crypto:decodeRsaPublicKeyFromTrustStore(keyStore, "keyAlias");
boolean isValid = check crypto:verifyRsaSsaPss256Signature(data, signature, publicKey);

Checklist

• Linked to an issue
• Updated the changelog
• Added tests
• Updated the spec
• Checked native-image compatibility

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

❌ Patch coverage is 79.73856% with 62 lines in your changes missing coverage. Please review.
✅ Project coverage is 82.14%. Comparing base (7210fa2) to head (21fde5f).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
...mpiler/staticcodeanalyzer/CryptoAnalyzerUtils.java	71.17%	7 Missing and 25 partials ⚠️
...o/compiler/staticcodeanalyzer/FunctionContext.java	79.31%	6 Missing and 6 partials ⚠️
...ctionrules/AvoidReusingCounterModeVectorsRule.java	77.14%	2 Missing and 6 partials ⚠️
...zer/functionrules/AvoidFastHashAlgorithmsRule.java	86.27%	2 Missing and 5 partials ⚠️
...ticcodeanalyzer/CryptoCipherAlgorithmAnalyzer.java	90.00%	0 Missing and 1 partial ⚠️
.../staticcodeanalyzer/CryptoFunctionRulesEngine.java	93.75%	0 Missing and 1 partial ⚠️
...r/functionrules/AvoidWeakCipherAlgorithmsRule.java	92.85%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #612      +/-   ##
============================================
- Coverage     82.32%   82.14%   -0.19%     
- Complexity      241      371     +130     
============================================
  Files            29       41      +12     
  Lines          1375     1725     +350     
  Branches        191      268      +77     
============================================
+ Hits           1132     1417     +285     
- Misses          196      215      +19     
- Partials         47       93      +46     

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[DimuthuMadushan]

@randilt, could you please update the PR with the requested changes?

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[randilt]

@DimuthuMadushan it looks like the PR is showing more changes than expected because the feature branch has diverged from master. Should I create a clean branch from master and cherry-pick only my commits to keep the PR tidy, or is this okay as is?

[daneshk]

@randilt, shall we remove scan tool-related changes from the PR? There are other commits as well Refactor scan rule implementation

[daneshk]

@DimuthuMadushan it looks like the PR is showing more changes than expected because the feature branch has diverged from master. Should I create a clean branch from master and cherry-pick only my commits to keep the PR tidy, or is this okay as is?

Please create a clean branch. We should not have other commits in this PR

[randilt]

@DimuthuMadushan it looks like the PR is showing more changes than expected because the feature branch has diverged from master. Should I create a clean branch from master and cherry-pick only my commits to keep the PR tidy, or is this okay as is?

Please create a clean branch. We should not have other commits in this PR

yes I will do that

[randilt]

Closing this PR as a new clean PR is created with the changes related to this feature @DimuthuMadushan @daneshk
#616