【发布时间】:2016-12-19 22:02:14
【问题描述】:
首先,对我即将发布的大量代码表示歉意。我正在尝试使用我的 Java 应用程序中的 RSA 公钥加密 Android 应用程序中的消息,然后将密文发送回 Java 环境进行解密,但在尝试解密时,我总是收到此错误:
javax.crypto.BadPaddingException: Decryption error
at sun.security.rsa.RSAPadding.unpadV15(RSAPadding.java:380)
at sun.security.rsa.RSAPadding.unpad(RSAPadding.java:291)
at com.sun.crypto.provider.RSACipher.doFinal(RSACipher.java:356)
at com.sun.crypto.provider.RSACipher.engineDoFinal(RSACipher.java:382)
at javax.crypto.Cipher.doFinal(Cipher.java:2087)
...
密文确实包含正确的字节数 (512),因此看到“错误填充”异常会令人困惑。 SO上的其他类似帖子建议使用“RSA/ECB/PKCS1Padding”作为算法,但这不起作用。
令人讨厌的是,Android 环境中的加密和解密(使用 Base64.URL_SAFE 作为“base64Type”)工作得很好,我似乎无法使用通过 Java 生成的公钥进行初始加密。
我已经将最少的代码提取到示例中,如下所示:
安卓代码
private void exampleMethod(){
String messageString = "Why does this not work in Android?";
String serverPubKey = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAoApIBIna77xq4j+M2RmyIhsB++41NHcY4KIPfX4VP4ADnkO+7ejbs4le/twrPtYGESVPF9czSMB5bzmTBZtq0jC8oT/6wiDIBlSuzo4fBrGociBIuaOjyG/j3ZhpcWpWPXuzER+ehuQ+8hZkMuJdK9IodqPR+5jmCef4rXoKObwS02LYQ1co5dEmtZVQRmmeYaVnWibd/s1d4KKGvSzXap3YBTf8peH5UGIQrLOTqvX0bo34xFxmj5U0H3xudnnwuVAlQlj9KiHPPABuwNtm1buRKJb5HZhSCveyT/2YAOmQqGrVN/nALtlZyTDZNs//Vp1zb9exSuG0t5xFc+pn4QIDAQAB";
String encryptedMessageString = getUrlEncodedCipherText(messageString, serverPubKey, Base64.NO_WRAP);
/**
* CipherText is ALWAYS the same and does not decrypt: DA_-RpCki-mjF6tSwiP2IhuW2UfPzZC7A9oVTTNptjT73HtROiQZvUC0Z2veJ5VwVx4toolvLErQmKKoQlqELSD756bu8ohEQwgJ4Xsu-3tXv-uEi5a9a_u19WnNLIF7tayDUhFeD2RzNvW895y1v-D30TvQRskNCFJfnjaytr_vmcVv8HrXURCmG6AMltaqdN72zh8p6VkKcjXSLiCApH957GXSqJCRzxbaQwf8X5EJfn8CQrPDGbE3gdhc2_hFwXQNIdxPxrOLtVbaFp9i_4GRWXJ6E2jHttV2bDv_uSVIz3OBzh7EkJiCnl3c904sH8QZae8c3SQyrTxVL7EpIA,,
*/
}
public static String getUrlEncodedCipherText(String plainText, String pubKey, int base64Type){
try {
final PublicKey publicKey = loadPublicKey(pubKey, base64Type);
final byte[] cipherBytes = encrypt(plainText, publicKey);
String cipherText = base64Encode(cipherBytes, base64Type);
String urlEncodedCipherText = urlEncode(cipherText);
return urlEncodedCipherText;
}
catch (Exception e){
e.printStackTrace();
return null;
}
}
public static final String ALGORITHM = "RSA";
public static PublicKey loadPublicKey(String stored, int base64Type) throws GeneralSecurityException {
String pubKey = stored.replace(BEGIN_PUBLIC_KEY, "");
pubKey = pubKey.replace(END_PUBLIC_KEY, "");
byte[] data = Base64.decode(pubKey, base64Type);
X509EncodedKeySpec spec = new X509EncodedKeySpec(data);
KeyFactory fact = KeyFactory.getInstance(ALGORITHM);
PublicKey pub = fact.generatePublic(spec);
return pub;
}
public static byte[] encrypt(String text, PublicKey key) {
byte[] cipherText = null;
try {
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, key);
cipherText = cipher.doFinal(text.getBytes());
}
catch (Exception e) {
e.printStackTrace();
}
return cipherText;
}
public static String base64Encode(byte[] cipherBytes, int base64Type){
byte[] base64Cipher = Base64.encode(cipherBytes, base64Type);
return new String(base64Cipher);
}
public static String urlEncode(String text){
return text.replace("+", "-").replace("/", "_").replace("=", ",");
}
Java 代码
private void exampleMethod(){
String pubKey = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAoApIBIna77xq4j+M2RmyIhsB++41NHcY4KIPfX4VP4ADnkO+7ejbs4le/twrPtYGESVPF9czSMB5bzmTBZtq0jC8oT/6wiDIBlSuzo4fBrGociBIuaOjyG/j3ZhpcWpWPXuzER+ehuQ+8hZkMuJdK9IodqPR+5jmCef4rXoKObwS02LYQ1co5dEmtZVQRmmeYaVnWibd/s1d4KKGvSzXap3YBTf8peH5UGIQrLOTqvX0bo34xFxmj5U0H3xudnnwuVAlQlj9KiHPPABuwNtm1buRKJb5HZhSCveyT/2YAOmQqGrVN/nALtlZyTDZNs//Vp1zb9exSuG0t5xFc+pn4QIDAQAB";
String privKey = "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";
String message = "Why does this not work in Android?";
String encryptedMessage = getUrlEncodedCipherText(message, pubKey);
try {
byte[] base64Decoded = Base64.decodeBase64(encryptedMessage.getBytes(Charset.forName("UTF-8")));
String decryptedMessage = decrypt(base64Decoded, loadPrivateKey(privKey));
System.out.println("decryptedMessage: " + decryptedMessage);
/**
* This works! Ciphertext always comes out different, as expected, and decodes successfully.
*/
}
catch (Exception e){
e.printStackTrace();
}
}
public static String getUrlEncodedCipherText(String plainText, String pubKey){
try {
final PublicKey publicKey = loadPublicKey(pubKey);
final byte[] cipherBytes = encrypt(plainText, publicKey);
String cipherText = base64Encode(cipherBytes);
String urlEncodedCipherText = urlEncode(cipherText);
return urlEncodedCipherText;
}
catch (Exception e){
e.printStackTrace();
return null;
}
}
public static final String ALGORITHM = "RSA";
public static PublicKey loadPublicKey(String stored) throws GeneralSecurityException {
String pubKey = stored.replace(BEGIN_PUBLIC_KEY, "");
pubKey = pubKey.replace(END_PUBLIC_KEY, "");
byte[] data = Base64.decodeBase64(pubKey);
X509EncodedKeySpec spec = new X509EncodedKeySpec(data);
KeyFactory fact = KeyFactory.getInstance(ALGORITHM);
PublicKey pub = fact.generatePublic(spec);
return pub;
}
public static byte[] encrypt(String text, PublicKey key) {
byte[] cipherText = null;
try {
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, key);
cipherText = cipher.doFinal(text.getBytes());
}
catch (Exception e) {
e.printStackTrace();
}
return cipherText;
}
public static String decrypt(byte[] encrypted, PrivateKey key) {
byte[] decryptedText = null;
try {
final Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, key);
decryptedText = cipher.doFinal(encrypted);
}
catch (Exception e) {
e.printStackTrace();
return null;
}
return new String(decryptedText);
}
public static String base64Encode(byte[] cipherBytes){
byte[] base64Cipher = Base64.encodeBase64(cipherBytes);
return new String(base64Cipher);
}
public static String urlEncode(String text){
return text.replace("+", "-").replace("/", "_").replace("=", ",");
}
我知道问题与 Android 和 Java 解释 RSA 算法的方式不同,和/或与 Base64 编码/解码的差异有关,但我很难过。非常感谢任何帮助。
【问题讨论】:
-
您的 URL 编码与 RFC4648 的
Table 2: The "URL and Filename safe" Base 64 Alphabet不一致。字符=不应编码为,。我认为这不是问题,但您可以查看它。我 -
还要注意,在 android 中,您可以使用
Base64.URL_SAFE编码为 base64url。事实上,在 POST 请求中,您也不需要使用 base64url 编码发送。使用 base64 就足够了 -
谢谢佩德罗。非标准的 URL 编码不是问题,因为我以类似的方式对其进行解码。我将尝试更多地关注实际的 Base64 编码。
标签: java android encryption base64 rsa