我想在
Android密钥库中生成一个RSA密钥对.由于Android 4.3应该可以在Android系统密钥库中生成RSA密钥.
我生成我的RSA密钥(工作正常)
Calendar notBefore = Calendar.getInstance();
Calendar notAfter = Calendar.getInstance();
notAfter.add(1,Calendar.YEAR);
KeyPairGeneratorSpec spec = new KeyPairGeneratorSpec.Builder(ctx)
.setAlias("key")
.setSubject(
new X500Principal(String.format("CN=%s,OU=%s","key",ctx.getPackageName())))
.setSerialNumber(BigInteger.ONE)
.setStartDate(notBefore.getTime())
.setEndDate(notAfter.getTime()).build();
KeyPairGenerator kpg;
kpg = KeyPairGenerator.getInstance("RSA","AndroidKeyStore");
kpg.initialize(spec);
KeyPair kp = kpg.genKeyPair();
publicKey = kp.getPublic();
privateKey = kp.getPrivate();
我的RSA加密看起来像(也是)：
public static byte[] RSAEncrypt(final byte[] plain)
throws NoSuchAlgorithmException,NoSuchPaddingException,InvalidKeyException,IllegalBlockSizeException,BadPaddingException {
Cipher cipher = Cipher.getInstance("RSA");
System.out.println("RSA Encryption key: " + publicKey.getAlgorithm());
System.out.println("RSA Encryption key: " + publicKey.getEncoded());
cipher.init(Cipher.ENCRYPT_MODE,publicKey);
byte[] encryptedBytes = cipher.doFinal(plain);
return encryptedBytes;
}
解密：
public static byte[] RSADecrypt(final byte[] encryptedBytes)
throws NoSuchAlgorithmException,BadPaddingException {
Cipher cipher1 = Cipher.getInstance("RSA");
System.out.println("RSA Encryption key: " + privateKey.getAlgorithm());
System.out.println("RSA Encryption key: " + privateKey.getEncoded());
cipher1.init(Cipher.DECRYPT_MODE,privateKey);
byte[] decryptedBytes = cipher1.doFinal(encryptedBytes);
return decryptedBytes;
}
在解密函数中,我收到以下错误消息(当privateKey被编码时,在cipher1.init()中)：
12-12 21:49:40.338: E/AndroidRuntime(20423): FATAL EXCEPTION: main 12-12 21:49:40.338: E/AndroidRuntime(20423): java.lang.UnsupportedOperationException: private exponent cannot be extracted 12-12 21:49:40.338: E/AndroidRuntime(20423): at org.apache.harmony.xnet.provider.jsse.OpenSSlrsAPrivateKey.getPrivateExponent(OpenSSlrsAPrivateKey.java:143)
我不明白是不是可以在Android KeyStore中生成RSA密钥？任何人都可以提供一个在Android KeyStore中生成RSA密钥并使用私钥解密的示例.
提前谢谢了！
解决方法
根据
the code,我认为OpenSSL提供程序防止在密钥生成到设备时导出私有指数.
@Override
public final BigInteger getPrivateExponent() {
if (key.isEngineBased()) {
throw new UnsupportedOperationException("private exponent cannot be extracted");
}
ensureReadParams();
return privateExponent;
}
因此,您可能需要指定在检索密码实例时要使用相同的加密提供程序.该提供商supports these RSA ciphers：
> RSA / ECB / nopadding
> RSA / ECB / PKCS1Padding
您应该以这种方式创建密码实例：
Cipher cipher1 = Cipher.getInstance("RSA/ECB/PKCS1Padding","AndroidOpenSSL");