声明：亲测，是可以互通的。
声明：本文摘抄来源http://www.jianshu.com/p/581380445eb4 作者totzcc
iOS代码地址https://gist.github.com/lvjian700/204c23226fdffd6a505d

1. 使用openssl生成密钥队，谷歌一下。注意：Java需要使用pkcs8 private key解密。
   2.pod 'Base64nl', '~> 1.2'
   3.iOS加密
   RSAEncryptor *rsa = [[RSAEncryptor alloc] init];
   NSLog(@"encryptor using rsa");
   NSString *publicKeyPath = [[NSBundle mainBundle] pathForResource:@"public_key" ofType:@"der"];
   NSLog(@"public key: %@", publicKeyPath);
   [rsa loadPublicKeyFromFile:publicKeyPath];
   NSString *securityText = @"hello ~";
   NSString *encryptedString = [rsa rsaEncryptString:securityText];
   NSLog(@"encrypted data: %@", encryptedString);
   4.Java解密
   基本步骤：
   加载pkcs8 private key:
   读取private key文件
   去掉private key头尾的"-----BEGIN PRIVATE KEY-----"和"-----BEGIN PRIVATE KEY-----"
   删除private key中的换行
   对处理后的数据进行Base64解码
   使用解码后的数据生成private key.
   解密数据:
   对数据进行Base64解码
   使用RSA decrypt数据.

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.InvalidKeyException;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.util.Base64;
import static java.lang.String.format;
public class Encryptor {
public static void main(String[] args) throws IOException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
PrivateKey privateKey = readPrivateKey();
String message = "AFppaFPTbmboMZD55cjCfrVaWUW7+hZkaq16Od+6fP0lwz/yC+Rshb/8cf5BpBlUao2EunchnzeKxzpiPqtCcCITKvk6HcFKZS0sN9wOhlQFYT+I4f/CZITwBVAJaldZ7mkyOiuvM+raXMwrS+7MLKgYXkd5cFPxEsTxpMSa5Nk=";
System.out.println(format("- decrypt rsa encrypted base64 message: %s", message));
// hello ~, encrypted and encoded with Base64:
byte[] data = encryptedData(message);
String text = decrypt(privateKey, data);
System.out.println(text);
}
private static String decrypt(PrivateKey privateKey, byte[] data) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
cipher.init(Cipher.DECRYPT_MODE, privateKey);
byte[] decryptedData = cipher.doFinal(data);
return new String(decryptedData);
}
private static byte[] encryptedData(String base64Text) {
return Base64.getDecoder().decode(base64Text.getBytes(Charset.forName("UTF-8")));
}
private static PrivateKey readPrivateKey() throws IOException, NoSuchAlgorithmException, InvalidKeySpecException {
byte[] privateKeyData = Files.readAllBytes(
Paths.get("/Users/twer/macspace/ios_workshop/Security/SecurityLogin/tools/pkcs8_private_key.pem"));
byte[] decodedKeyData = Base64.getDecoder()
.decode(new String(privateKeyData)
.replaceAll("-----\w+ PRIVATE KEY-----", "")
.replace("\n", "")
.getBytes());
return KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decodedKeyData));
}
}