Added new function - JwtTokenResolver.parse() (#113)

Author: artem-v

tests/src/test/java/io/scalecube/security/tokens/jwt/JsonwebtokenResolverTests.java

@@ -43,6 +43,25 @@ void testResolveTokenSuccessfully(VaultEnvironment vaultEnvironment) throws Exce
     assertTrue(jwtToken.payload().size() > 0, "jwtToken.payload: " + jwtToken.payload());
   }
 
+  @Test
+  void testParseTokenSuccessfully(VaultEnvironment vaultEnvironment) {
+    final var token = vaultEnvironment.newServiceToken();
+
+    final var jwtToken =
+        new JsonwebtokenResolver(
+                JwksKeyLocator.builder()
+                    .jwksUri(vaultEnvironment.jwksUri())
+                    .connectTimeout(Duration.ofSeconds(3))
+                    .requestTimeout(Duration.ofSeconds(3))
+                    .keyTtl(1000)
+                    .build())
+            .parse(token);
+
+    assertNotNull(jwtToken, "jwtToken");
+    assertTrue(jwtToken.header().size() > 0, "jwtToken.header: " + jwtToken.header());
+    assertTrue(jwtToken.payload().size() > 0, "jwtToken.payload: " + jwtToken.payload());
+  }
+
   @Test
   void testJwksKeyLocatorThrowsError(VaultEnvironment vaultEnvironment) {
     final var token = vaultEnvironment.newServiceToken();

tokens/src/main/java/io/scalecube/security/tokens/jwt/JsonwebtokenResolver.java

@@ -1,8 +1,13 @@
 package io.scalecube.security.tokens.jwt;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import io.jsonwebtoken.Jwts;
 import io.jsonwebtoken.Locator;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.security.Key;
+import java.util.Base64;
+import java.util.Map;
 import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
 import org.slf4j.Logger;
@@ -30,21 +35,44 @@ public CompletableFuture<JwtToken> resolve(String token) {
             (jwtToken, ex) -> {
               if (jwtToken != null) {
                 if (LOGGER.isDebugEnabled()) {
-                  LOGGER.debug("Resolved token: {}", mask(token));
+                  LOGGER.debug("Resolved JWT: {}", mask(token));
                 }
                 return jwtToken;
               }
               if (ex != null) {
                 if (ex instanceof JwtTokenException) {
                   throw (JwtTokenException) ex;
                 } else {
-                  throw new JwtTokenException("Failed to resolve token: " + mask(token), ex);
+                  throw new JwtTokenException("Failed to resolve JWT: " + mask(token), ex);
                 }
               }
               return null;
             });
   }
 
+  @Override
+  public JwtToken parse(String token) {
+    String[] parts = token.split("\\.");
+    if (parts.length != 3) {
+      throw new JwtTokenException("Invalid JWT format");
+    }
+
+    try {
+      final var urlDecoder = Base64.getUrlDecoder();
+      final var headerJson = new String(urlDecoder.decode(parts[0]), StandardCharsets.UTF_8);
+      final var payloadJson = new String(urlDecoder.decode(parts[1]), StandardCharsets.UTF_8);
+
+      final var mapper = new ObjectMapper();
+      final var header = mapper.readValue(headerJson, Map.class);
+      final var claims = mapper.readValue(payloadJson, Map.class);
+
+      //noinspection unchecked
+      return new JwtToken(header, claims);
+    } catch (IOException e) {
+      throw new JwtTokenException("Failed to decode JWT", e);
+    }
+  }
+
   private static String mask(String data) {
     if (data == null || data.length() < 5) {
       return "*****";

tokens/src/main/java/io/scalecube/security/tokens/jwt/JwtTokenResolver.java

@@ -5,10 +5,18 @@
 public interface JwtTokenResolver {
 
   /**
-   * Verifies and returns token claims.
+   * Verifies given JWT and parses its header and claims.
    *
    * @param token jwt token
-   * @return mono result with parsed claims (or error)
+   * @return async result with {@link JwtToken}, or error
    */
   CompletableFuture<JwtToken> resolve(String token);
+
+  /**
+   * Parses given JWT without verifying its signature.
+   *
+   * @param token jwt token
+   * @return parsed token
+   */
+  JwtToken parse(String token);
 }