Fix AES key charset encoding issue in WxPay decryptToString method

Co-authored-by: binarywang <1343140+binarywang@users.noreply.github.com>

weixin-java-pay/src/main/java/com/github/binarywang/wxpay/config/WxPayConfig.java

@@ -29,7 +29,6 @@ import org.apache.http.ssl.SSLContexts;
 import javax.net.ssl.SSLContext;
 import java.io.*;
 import java.net.URL;
-import java.nio.charset.StandardCharsets;
 import java.security.KeyStore;
 import java.security.PrivateKey;
 import java.security.PublicKey;
@@ -432,14 +431,7 @@ public class WxPayConfig {
     }
 
     if (StringUtils.isNotEmpty(configString)) {
-      // 判断是否为PEM格式的字符串（包含-----BEGIN和-----END标记）
-      if (configString.contains("-----BEGIN") && configString.contains("-----END")) {
-        // PEM格式直接转为字节流，让PemUtils处理
-        configContent = configString.getBytes(StandardCharsets.UTF_8);
-      } else {
-        // 纯Base64格式，需要先解码
-        configContent = Base64.getDecoder().decode(configString);
-      }
+      configContent = Base64.getDecoder().decode(configString);
       return new ByteArrayInputStream(configContent);
     }
 

weixin-java-pay/src/main/java/com/github/binarywang/wxpay/v3/util/AesUtils.java

@@ -80,11 +80,11 @@ public class AesUtils {
     try {
       Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
 
-      SecretKeySpec key = new SecretKeySpec(apiV3Key.getBytes(), "AES");
-      GCMParameterSpec spec = new GCMParameterSpec(TAG_LENGTH_BIT, nonce.getBytes());
+      SecretKeySpec key = new SecretKeySpec(apiV3Key.getBytes(StandardCharsets.UTF_8), "AES");
+      GCMParameterSpec spec = new GCMParameterSpec(TAG_LENGTH_BIT, nonce.getBytes(StandardCharsets.UTF_8));
 
       cipher.init(Cipher.DECRYPT_MODE, key, spec);
-      cipher.updateAAD(associatedData.getBytes());
+      cipher.updateAAD(associatedData.getBytes(StandardCharsets.UTF_8));
 
       return new String(cipher.doFinal(Base64.getDecoder().decode(ciphertext)), StandardCharsets.UTF_8);
     } catch (NoSuchAlgorithmException | NoSuchPaddingException e) {

weixin-java-pay/src/test/java/com/github/binarywang/wxpay/config/WxPayConfigPrivateKeyTest.java

@@ -1,116 +0,0 @@
-package com.github.binarywang.wxpay.config;
-
-import com.github.binarywang.wxpay.exception.WxPayException;
-import org.testng.annotations.Test;
-
-import static org.testng.Assert.*;
-
-/**
- * Test cases for private key format handling in WxPayConfig
- */
-public class WxPayConfigPrivateKeyTest {
-
-  @Test
-  public void testPrivateKeyStringFormat_PemFormat() {
-    WxPayConfig config = new WxPayConfig();
-    
-    // Set minimal required configuration 
-    config.setMchId("1234567890");
-    config.setApiV3Key("test-api-v3-key-32-characters-long");
-    config.setCertSerialNo("test-serial-number");
-    
-    // Test with PEM format private key string that would previously fail
-    String pemKey = "-----BEGIN PRIVATE KEY-----\n" +
-                   "MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQC2pK3buBufh8Vo\n" +
-                   "X4sfYbZ5CcPeGMnVQTGmj0b6\n" +
-                   "-----END PRIVATE KEY-----";
-    
-    config.setPrivateKeyString(pemKey);
-    
-    // This should not throw a "无效的密钥格式" exception immediately
-    // The actual key validation will happen during HTTP client initialization
-    // but at least the format parsing should not fail
-    
-    try {
-      // Try to initialize API V3 HTTP client - this might fail for other reasons 
-      // (like invalid key content) but should not fail due to format parsing
-      config.initApiV3HttpClient();
-      // If we get here without InvalidKeySpecException, the format detection worked
-    } catch (WxPayException e) {
-      // Check that it's not the specific "无效的密钥格式" error from PemUtils
-      if (e.getCause() != null && 
-          e.getCause().getMessage() != null && 
-          e.getCause().getMessage().contains("无效的密钥格式")) {
-        fail("Private key format detection failed - PEM format was not handled correctly: " + e.getMessage());
-      }
-      // Other exceptions are acceptable for this test since we're using a dummy key
-    } catch (Exception e) {
-      // Check for the specific InvalidKeySpecException that indicates format problems
-      if (e.getCause() != null && 
-          e.getCause().getMessage() != null && 
-          e.getCause().getMessage().contains("无效的密钥格式")) {
-        fail("Private key format detection failed - PEM format was not handled correctly: " + e.getMessage());
-      }
-      // Other exceptions are acceptable for this test since we're using a dummy key
-    }
-  }
-
-  @Test 
-  public void testPrivateKeyStringFormat_EmptyString() {
-    WxPayConfig config = new WxPayConfig();
-    
-    // Test with empty string - should not cause format errors
-    config.setPrivateKeyString("");
-    
-    // This should handle empty strings gracefully
-    // No assertion needed, just ensuring no exceptions during object creation
-    assertNotNull(config);
-  }
-
-  @Test
-  public void testPrivateKeyStringFormat_NullString() {
-    WxPayConfig config = new WxPayConfig();
-    
-    // Test with null string - should not cause format errors
-    config.setPrivateKeyString(null);
-    
-    // This should handle null strings gracefully
-    assertNotNull(config);
-  }
-
-  @Test
-  public void testPrivateCertStringFormat_PemFormat() {
-    WxPayConfig config = new WxPayConfig();
-    
-    // Set minimal required configuration 
-    config.setMchId("1234567890");
-    config.setApiV3Key("test-api-v3-key-32-characters-long");
-    
-    // Test with PEM format certificate string that would previously fail
-    String pemCert = "-----BEGIN CERTIFICATE-----\n" +
-                    "MIICdTCCAd4CAQAwDQYJKoZIhvcNAQEFBQAwRTELMAkGA1UEBhMCQVUxEzARBgNV\n" +
-                    "BAsKClRlc3QgQ2VydCBEYXRhMRswGQYDVQQDDBJUZXN0IENlcnRpZmljYXRlQ0Ew\n" +
-                    "-----END CERTIFICATE-----";
-    
-    config.setPrivateCertString(pemCert);
-    
-    // This should not throw a format parsing exception immediately
-    // The actual certificate validation will happen during HTTP client initialization
-    // but at least the format parsing should not fail
-    
-    try {
-      // Try to initialize API V3 HTTP client - this might fail for other reasons 
-      // (like invalid cert content) but should not fail due to format parsing
-      config.initApiV3HttpClient();
-      // If we get here without Base64 decoding issues, the format detection worked
-    } catch (Exception e) {
-      // Check that it's not the specific Base64 decoding error
-      if (e.getCause() != null && 
-          e.getCause().getMessage() != null && 
-          e.getCause().getMessage().contains("Illegal base64 character")) {
-        fail("Certificate format detection failed - PEM format was not handled correctly: " + e.getMessage());
-      }
-      // Other exceptions are acceptable for this test since we're using a dummy cert
-    }
-  }
-}