Set up creatJwkException in exceptionUtils and apply that in JwtVendo…

…r constructor

Signed-off-by: Ryan Liang <jiallian@amazon.com>

src/main/java/org/opensearch/security/authtoken/jwt/JwtVendor.java

@@ -30,6 +30,7 @@
 import org.apache.logging.log4j.Logger;
 
 import org.opensearch.common.settings.Settings;
+import org.opensearch.security.ssl.util.ExceptionUtils;
 import org.opensearch.security.support.ConfigConstants;
 
 public class JwtVendor {
@@ -48,11 +49,11 @@ public JwtVendor(final Settings settings, final Optional<LongSupplier> timeProvi
         try {
             this.signingKey = createJwkFromSettings(settings);
         } catch (Exception e) {
-            throw new RuntimeException(e);
+            throw ExceptionUtils.createJwkCreationException(e);
         }
         this.jwtProducer = jwtProducer;
         if (settings.get("encryption_key") == null) {
-            throw new RuntimeException("encryption_key cannot be null");
+            throw new IllegalArgumentException("encryption_key cannot be null");
         } else {
             this.claimsEncryptionKey = settings.get("encryption_key");
         }

src/main/java/org/opensearch/security/ssl/util/ExceptionUtils.java

@@ -68,6 +68,14 @@ public static OpenSearchException invalidUsageOfOBOTokenException() {
         return new OpenSearchException("On-Behalf-Of Token is not allowed to be used for accessing this endpoint.");
     }
 
+    public static OpenSearchException createJwkCreationException() {
+        return new OpenSearchException("An error occurred during the creation of Jwk.");
+    }
+
+    public static OpenSearchException createJwkCreationException(Throwable cause) {
+        return new OpenSearchException("An error occurred during the creation of Jwk: {}", cause, cause.getMessage());
+    }
+
     public static OpenSearchException createTransportClientNoLongerSupportedException() {
         return new OpenSearchException("Transport client authentication no longer supported.");
     }