NimbusJwtEncoder should simplify constructing with javax.security Keys

[surajbh123]

No description provided.

[surajbh123]

Working on test cases and code refactoring

[surajbh123]

Helper Methods for Key Generation

        // 1. Using SecretKey with defaults
        SecretKey defaultSecretKey = createSecretKey("HmacSHA256", 256); // Key for default HS256
        NimbusJwtEncoder encoderWithSecretDefaults = NimbusJwtEncoder.withSecretKey(defaultSecretKey)
                // .macAlgorithm(MacAlgorithm.HS256) // Default is HS256
                // .keyId(null)                     // Default keyId is null
                // .jwkSelector(...)               // Default selector throws if multiple keys match
                .build();
                
        // 2. Using SecretKey with specific algorithm and keyId
        SecretKey hs512SecretKey = createSecretKey("HmacSHA512", 512);
        String secretKeyId = "my-hmac-key-01";
        NimbusJwtEncoder encoderWithSecretCustom = NimbusJwtEncoder.withSecretKey(hs512SecretKey)
                .macAlgorithm(MacAlgorithm.HS512) // Specify HS512
                .keyId(secretKeyId)               // Specify a key ID
                .build();

        // 3. Using RSA KeyPair with defaults
        KeyPair rsaKeyPair = createRsaKeyPair(2048);
        NimbusJwtEncoder encoderWithRsaDefaults = NimbusJwtEncoder.withKeyPair(rsaKeyPair)
                // .signatureAlgorithm(SignatureAlgorithm.RS256) // Default for RSA is RS256
                // .keyId(UUID generated)                      // Default keyId is a random UUID
                // .jwkSelector(...)                          // Default selector picks first if multiple
                .build();
                
        // 4. Using RSA KeyPair with specific algorithm (PSS) and keyId
        String rsaKeyId = "my-rsa-key-01";
        NimbusJwtEncoder encoderWithRsaCustom = NimbusJwtEncoder.withKeyPair(rsaKeyPair)
                .signatureAlgorithm(SignatureAlgorithm.PS256) // Specify PS256
                .keyId(rsaKeyId)                              // Specify a key ID
                .build();

        // 5. Using EC KeyPair with defaults
        KeyPair ecP256KeyPair = createEcKeyPair(Curve.P_256); // Key for default ES256
        NimbusJwtEncoder encoderWithEcDefaults = NimbusJwtEncoder.withKeyPair(ecP256KeyPair)
                // .signatureAlgorithm(SignatureAlgorithm.ES256) // Default for EC is ES256
                // .keyId(UUID generated)                      // Default keyId is a random UUID
                // .jwkSelector(...)                          // Default selector picks first if multiple
                .build();

        // 6. Using EC KeyPair with specific algorithm and keyId
        KeyPair ecP521KeyPair = createEcKeyPair(Curve.P_521); // Key for ES512
        String ecKeyId = "my-ec-key-01";
        NimbusJwtEncoder encoderWithEcCustom = NimbusJwtEncoder.withKeyPair(ecP521KeyPair)
                .signatureAlgorithm(SignatureAlgorithm.ES512) // Specify ES512
                .keyId(ecKeyId)                               // Specify a key ID
                .build();

[jzheaux]

Thanks, @surajbh123! This PR will make using NimbusJwtEncoder much simpler.

I've left my feedback inline. In addition to that, please ensure that your commit only has the signoff in the description and not in the title. Please also ensure that the description has the issue that this PR resolves:

Add NimbusJwtEncoder Builders

Closes gh-16267

Signed-off-by ...

[jzheaux]

Let's please set a default JWSAlgorithm.

[surajbh123]

Added in buildJwk() as now we have two separate builder for RSA and EC

[jzheaux]

Just one more thing, @surajbh123, when you submit, it will save you time in the review process if you run the following before submitting:

./gradlew format && ./gradlew :spring-security-oauth2-jose:check

[surajbh123]

Working on reviews comments
Not all resolved yet

[jzheaux]

Thanks for the quick turnaround, @surajbh123! This is coming together nicely. I've added some additional inline feedback.

[jzheaux]

Please check for null here instead of in encode. You can use Assert.notNull for this.

[surajbh123]

it can never be null here
as we setting default value if jws header is null i.e. not sent by user

[jzheaux]

Since you are giving this a default value and there isn't a way for the application to set it back to null, I believe you can remove this line.

[surajbh123]

In the following case, it may be null.

    SecretKey defaultSecretKey = createSecretKey("HmacSHA256", 256); // Key for default HS256
    NimbusJwtEncoder encoderWithSecretDefaults = NimbusJwtEncoder.withSecretKey(defaultSecretKey)
            // .macAlgorithm(MacAlgorithm.HS256) // Default is HS256
            // .keyId(null)                     // Default keyId is null
            // .jwkSelector(...)               // Default selector throws if multiple keys match
            .build();