java生成pkcs1 rsa密钥对

以下是使用Java生成PKCS#1 RSA密钥对的示例代码：

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;

import javax.crypto.Cipher;

public class RSATest {
    
    public static void main(String[] args) throws Exception {
        // 生成RSA密钥对
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
        keyPairGen.initialize(2048);
        KeyPair keyPair = keyPairGen.generateKeyPair();
        PublicKey publicKey = keyPair.getPublic();
        PrivateKey privateKey = keyPair.getPrivate();
        
        // 将公钥和私钥转换成PKCS#1格式
        byte[] pkcs1PublicKey = getPKCS1PublicKey((RSAPublicKey) publicKey);
        byte[] pkcs1PrivateKey = getPKCS1PrivateKey((RSAPrivateKey) privateKey);
        
        // 打印公钥和私钥
        System.out.println("PKCS#1公钥：" + bytesToHex(pkcs1PublicKey));
        System.out.println("PKCS#1私钥：" + bytesToHex(pkcs1PrivateKey));
    }
    
    /**
     * 将RSA公钥转换成PKCS#1格式
     */
    public static byte[] getPKCS1PublicKey(RSAPublicKey publicKey) throws Exception {
        byte[] encoded = publicKey.getEncoded();
        int totalLength = encoded.length + 22;
        byte[] pkcs1PublicKey = new byte[totalLength];
        pkcs1PublicKey[0] = 0x30;
        pkcs1PublicKey[1] = (byte) (totalLength - 2);
        pkcs1PublicKey[2] = 0x30;
        pkcs1PublicKey[3] = 0x0d;
        pkcs1PublicKey[4] = 0x06;
        pkcs1PublicKey[5] = 0x09;
        pkcs1PublicKey[6] = 0x2a;
        pkcs1PublicKey[7] = 0x86;
        pkcs1PublicKey[8] = 0x48;
        pkcs1PublicKey[9] = (byte) 0x86;
        pkcs1PublicKey[10] = (byte) 0xf7;
        pkcs1PublicKey[11] = 0x0d;
        pkcs1PublicKey[12] = 0x01;
        pkcs1PublicKey[13] = 0x01;
        pkcs1PublicKey[14] = 0x01;
        pkcs1PublicKey[15] = 0x05;
        pkcs1PublicKey[16] = 0x00;
        pkcs1PublicKey[17] = 0x03;
        pkcs1PublicKey[18] = 0x81;
        pkcs1PublicKey[19] = 0x00;
        byte[] modulus = publicKey.getModulus().toByteArray();
        System.arraycopy(modulus, 0, pkcs1PublicKey, 22 + modulus.length - publicKey.getModulus().bitLength() / 8, modulus.length);
        return pkcs1PublicKey;
    }
    
    /**
     * 将RSA私钥转换成PKCS#1格式
     */
    public static byte[] getPKCS1PrivateKey(RSAPrivateKey privateKey) throws Exception {
        byte[] encoded = privateKey.getEncoded();
        int totalLength = encoded.length + 26;
        byte[] pkcs1PrivateKey = new byte[totalLength];
        pkcs1PrivateKey[0] = 0x30;
        pkcs1PrivateKey[1] = (byte) (totalLength - 2);
        pkcs1PrivateKey[2] = 0x02;
        pkcs1PrivateKey[3] = 0x01;
        pkcs1PrivateKey[4] = 0x00;
        pkcs1PrivateKey[5] = 0x30;
        pkcs1PrivateKey[6] = 0x0d;
        pkcs1PrivateKey[7] = 0x06;
        pkcs1PrivateKey[8] = 0x09;
        pkcs1PrivateKey[9] = 0x2a;
        pkcs1PrivateKey[10] = (byte) 0x86;
        pkcs1PrivateKey[11] = (byte) 0x48;
        pkcs1PrivateKey[12] = (byte) 0x86;
        pkcs1PrivateKey[13] = (byte) 0xf7;
        pkcs1PrivateKey[14] = 0x0d;
        pkcs1PrivateKey[15] = 0x01;
        pkcs1PrivateKey[16] = 0x01;
        pkcs1PrivateKey[17] = 0x01;
        pkcs1PrivateKey[18] = 0x05;
        pkcs1PrivateKey[19] = 0x00;
        pkcs1PrivateKey[20] = 0x04;
        byte[] modulus = privateKey.getModulus().toByteArray();
        System.arraycopy(modulus, 0, pkcs1PrivateKey, 24 + modulus.length - privateKey.getModulus().bitLength() / 8, modulus.length);
        pkcs1PrivateKey[24 + modulus.length - privateKey.getModulus().bitLength() / 8 - 2] = 0x02;
        byte[] exponent = privateKey.getPrivateExponent().toByteArray();
        System.arraycopy(exponent, 0, pkcs1PrivateKey, 24 + modulus.length + exponent.length - privateKey.getModulus().bitLength() / 8 - privateKey.getPrivateExponent().bitLength() / 8 - 1, exponent.length);
        return pkcs1PrivateKey;
    }
    
    /**
     * 将byte数组转换成十六进制字符串
     */
    public static String bytesToHex(byte[] bytes) {
        StringBuilder sb = new StringBuilder();
        for (byte b : bytes) {
            sb.append(String.format("%02X", b));
        }
        return sb.toString();
    }
    
}

该代码生成一个2048位的RSA密钥对，并将公钥和私钥转换成PKCS#1格式。可以通过调用`getPKCS1PublicKey`方法和`getPKCS1PrivateKey`方法获取PKCS#1公钥和私钥。