From e8c124d8ec4ea9e9d346e87386c35896a7fc9742 Mon Sep 17 00:00:00 2001
From: Zihlu Wang <really@zihlu.wang>
Date: Thu, 25 Jan 2024 23:34:20 +0800
Subject: [PATCH] fix: Fix the issue that reports illegal base64 character when
 decoding a JWT Payload

---
 .../codecrafters/devkit/utils/Base64Util.java | 64 +++++++++++++++++++
 .../authzero/AuthzeroTokenResolver.java       |  4 +-
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/devkit-utils/src/main/java/cn/org/codecrafters/devkit/utils/Base64Util.java b/devkit-utils/src/main/java/cn/org/codecrafters/devkit/utils/Base64Util.java
index 309b83c..0f38bc6 100644
--- a/devkit-utils/src/main/java/cn/org/codecrafters/devkit/utils/Base64Util.java
+++ b/devkit-utils/src/main/java/cn/org/codecrafters/devkit/utils/Base64Util.java
@@ -60,6 +60,10 @@ public final class Base64Util {
 
     private static Base64.Decoder decoder;
 
+    private static Base64.Encoder urlEncoder;
+
+    private static Base64.Decoder urlDecoder;
+
     /**
      * Ensure that there is only one Base64 Encoder.
      *
@@ -84,6 +88,20 @@ public final class Base64Util {
         return decoder;
     }
 
+    private static Base64.Encoder getUrlEncoder() {
+        if (Objects.isNull(urlEncoder)) {
+            urlEncoder = Base64.getUrlEncoder();
+        }
+        return urlEncoder;
+    }
+
+    public static Base64.Decoder getUrlDecoder() {
+        if (Objects.isNull(urlDecoder)) {
+            urlDecoder = Base64.getUrlDecoder();
+        }
+        return urlDecoder;
+    }
+
     /**
      * Private constructor to prevent instantiation of the class.
      */
@@ -136,4 +154,50 @@ public final class Base64Util {
         return decode(value, StandardCharsets.UTF_8);
     }
 
+    /**
+     * Encodes the given string using the specified charset.
+     *
+     * @param value   the string to be encoded
+     * @param charset the charset to be used for encoding
+     * @return the Base64 encoded string
+     */
+    public static String encodeUrlComponents(String value, Charset charset) {
+        var encoded = getUrlEncoder().encode(value.getBytes(charset));
+
+        return new String(encoded);
+    }
+
+    /**
+     * Encodes the given string using the default UTF-8 charset.
+     *
+     * @param value the string to be encoded
+     * @return the Base64 encoded string
+     */
+    public static String encodeUrlComponents(String value) {
+        return encodeUrlComponents(value, StandardCharsets.UTF_8);
+    }
+
+    /**
+     * Decodes the given Base64 encoded string using the specified charset.
+     *
+     * @param value   the Base64 encoded string to be decoded
+     * @param charset the charset to be used for decoding
+     * @return the decoded string
+     */
+    public static String decodeUrlComponents(String value, Charset charset) {
+        var decoded = getUrlDecoder().decode(value.getBytes(charset));
+
+        return new String(decoded);
+    }
+
+    /**
+     * Decodes the given Base64 encoded string using the default UTF-8 charset.
+     *
+     * @param value the Base64 encoded string to be decoded
+     * @return the decoded string
+     */
+    public static String decodeUrlComponents(String value) {
+        return decodeUrlComponents(value, StandardCharsets.UTF_8);
+    }
+
 }
\ No newline at end of file
diff --git a/simple-jwt-authzero/src/main/java/cn/org/codecrafters/simplejwt/authzero/AuthzeroTokenResolver.java b/simple-jwt-authzero/src/main/java/cn/org/codecrafters/simplejwt/authzero/AuthzeroTokenResolver.java
index e60e1d4..80d3eaa 100644
--- a/simple-jwt-authzero/src/main/java/cn/org/codecrafters/simplejwt/authzero/AuthzeroTokenResolver.java
+++ b/simple-jwt-authzero/src/main/java/cn/org/codecrafters/simplejwt/authzero/AuthzeroTokenResolver.java
@@ -429,7 +429,7 @@ public class AuthzeroTokenResolver implements TokenResolver<DecodedJWT> {
     public <T extends TokenPayload> T extract(String token, Class<T> targetType) {
         try {
             // Get claims from token.
-            var payloads = objectMapper.readValue(Base64Util.decode(resolve(token).getPayload()), new MapTypeReference());
+            var payloads = objectMapper.readValue(Base64Util.decodeUrlComponents(resolve(token).getPayload()), new MapTypeReference());
             // Get the no-argument constructor to create an instance.
             var bean = targetType.getConstructor().newInstance();
 
@@ -478,7 +478,7 @@ public class AuthzeroTokenResolver implements TokenResolver<DecodedJWT> {
         var resolved = resolve(oldToken);
 
         try {
-            var payload = objectMapper.readValue(Base64Util.decode(resolved.getPayload()), ObjectNode.class);
+            var payload = objectMapper.readValue(Base64Util.decodeUrlComponents(resolved.getPayload()), ObjectNode.class);
             payload.remove(PredefinedKeys.KEYS);
 
             var payloadMap = objectMapper.convertValue(payload, new MapTypeReference());