生成私钥
openssl genrsa -out rsa_private_key.pem 1024
导出公钥
openssl rsa -in rsa_private_key.pem -out rsa_public_key.pem -pubout
私钥转PKCS#8编码
openssl pkcs8 -topk8 -in rsa_private_key.pem -out pkcs8_rsa_private_key.pem -nocrypt
初始化公私钥
实例化RSA：
RSA rsa = new RSA()
加载公私钥文件：
basepath + privateKeyFilePKCS1 私钥文件路径
basepath + publicKeyFile 公钥文件路径
rsa.loadPrivateKeyPKCS1(new FileInputStream(new File(basepath + privateKeyFilePKCS1)));
rsa.loadPublicKey(new FileInputStream(new File(basepath + publicKeyFile)));
签名
构造待签原文数据
String content = "qwertyuiop1234567890";
原文数据使用base64编码
String contentBase64 = Base64.encodeBase64String(content.getBytes());
签名方法，返回签名结果使用base64编码
String signBase64 = rsa.signBase64(rsa.getPrivateKey(), contentBase64);
验证签名
contentBase64 ： 签名原文base64编码
signBase64 ： 签名结果base64编码
返回签名结果
boolean rs = rsa.verifyBase64(rsa.getPublicKey(), contentBase64, signBase64);
源代码
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.pkcs.RSAPrivateKeyStructure;
/**
* @author
* @date 2014-11-1
* @time 下午12:02:35
*
*/
public class RSA {
public static final String DEFAULT_PUBLIC_KEY = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQChDzcjw/rWgFwnxunbKp7/4e8w" + "\r"
+ "/UmXx2jk6qEEn69t6N2R1i/LmcyDT1xr/T2AHGOiXNQ5V8W4iCaaeNawi7aJaRht" + "\r"
+ "Vx1uOH/2U378fscEESEG8XDqll0GCfB1/TjKI2aitVSzXOtRs8kYgGU78f7VmDNg" + "\r" + "XIlk3gdhnzh+uoEQywIDAQAB" + "\r";
public static final String DEFAULT_PRIVATE_KEY = "MIICdQIBADANBgkqhkiG9w0BAQEFAASCAl8wggJbAgEAAoGBAKEPNyPD+taAXCfG" + "\r"
+ "6dsqnv/h7zD9SZfHaOTqoQSfr23o3ZHWL8uZzINPXGv9PYAcY6Jc1DlXxbiIJpp4" + "\r"
+ "1rCLtolpGG1XHW44f/ZTfvx+xwQRIQbxcOqWXQYJ8HX9OMojZqK1VLNc61GzyRiA" + "\r"
+ "ZTvx/tWYM2BciWTeB2GfOH66gRDLAgMBAAECgYBp4qTvoJKynuT3SbDJY/XwaEtm" + "\r"
+ "u768SF9P0GlXrtwYuDWjAVue0VhBI9WxMWZTaVafkcP8hxX4QZqPh84td0zjcq3j" + "\r"
+ "DLOegAFJkIorGzq5FyK7ydBoU1TLjFV459c8dTZMTu+LgsOTD11/V/Jr4NJxIudo" + "\r"
+ "MBQ3c4cHmOoYv4uzkQJBANR+7Fc3e6oZgqTOesqPSPqljbsdF9E4x4eDFuOecCkJ" + "\r"
+ "DvVLOOoAzvtHfAiUp+H3fk4hXRpALiNBEHiIdhIuX2UCQQDCCHiPHFd4gC58yyCM" + "\r"
+ "6Leqkmoa+6YpfRb3oxykLBXcWx7DtbX+ayKy5OQmnkEG+MW8XB8wAdiUl0/tb6cQ" + "\r"
+ "FaRvAkBhvP94Hk0DMDinFVHlWYJ3xy4pongSA8vCyMj+aSGtvjzjFnZXK4gIjBjA" + "\r"
+ "2Z9ekDfIOBBawqp2DLdGuX2VXz8BAkByMuIh+KBSv76cnEDwLhfLQJlKgEnvqTvX" + "\r"
+ "TB0TUw8avlaBAXW34/5sI+NUB1hmbgyTK/T/IFcEPXpBWLGO+e3pAkAGWLpnH0Zh" + "\r"
+ "Fae7oAqkMAd3xCNY6ec180tAe57hZ6kS+SYLKwb4gGzYaCxc22vMtYksXHtUeamo" + "\r" + "1NMLzI2ZfUoX" + "\r";
/**
* 私钥
*/
private RSAPrivateKey privateKey;
/**
* 公钥
*/
private RSAPublicKey publicKey;
public RSAPrivateKey getPrivateKey() {
return privateKey;
}
public RSAPublicKey getPublicKey() {
return publicKey;
}
/**
* 随机生成密钥对
*/
public void genKeyPair() {
KeyPairGenerator keyPairGen = null;
try {
keyPairGen = KeyPairGenerator.getInstance("RSA");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
keyPairGen.initialize(1024, new SecureRandom());
KeyPair keyPair = keyPairGen.generateKeyPair();
this.privateKey = (RSAPrivateKey) keyPair.getPrivate();
this.publicKey = (RSAPublicKey) keyPair.getPublic();
}
/**
* 从文件中输入流中加载公钥
*
* @param in
* 公钥输入流
* @throws Exception
* 加载公钥时产生的异常
*/
public void loadPublicKey(InputStream in) throws Exception {
try {
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String readLine = null;
StringBuilder sb = new StringBuilder();
while ((readLine = br.readLine()) != null) {
if (readLine.charAt(0) == ‘-‘) {
continue;
} else {
sb.append(readLine);
sb.append(‘\r‘);
}
}
loadPublicKey(sb.toString());
} catch (IOException e) {
throw new Exception("公钥数据流读取错误");
} catch (NullPointerException e) {
throw new Exception("公钥输入流为空");
}
}
/**
* 从字符串中加载公钥
*
* @param publicKeyStr
* 公钥数据字符串
* @throws Exception
* 加载公钥时产生的异常
*/
public void loadPublicKey(String publicKeyStr) throws Exception {
byte[] buffer = Base64.decodeBase64(publicKeyStr);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
this.publicKey = (RSAPublicKey) keyFactory.generatePublic(keySpec);
}
public void loadPrivateKeyPKCS1(InputStream in) throws Exception{
try {
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String readLine = null;
StringBuilder sb = new StringBuilder();
while ((readLine = br.readLine()) != null) {
if (readLine.charAt(0) == ‘-‘) {
continue;
} else {
sb.append(readLine);
sb.append(‘\r‘);
}
}
loadPrivateKeyPKCS1(sb.toString());
} catch (IOException e) {
throw new Exception("私钥数据读取错误");
} catch (NullPointerException e) {
throw new Exception("私钥输入流为空");
}
}
public void loadPrivateKeyPKCS1(String privateKeyStr) throws Exception{
System.out.println("load-privateKey-PKCS#1");
byte[] buffer = Base64.decodeBase64(privateKeyStr);
RSAPrivateKeyStructure asn1PrivKey = new RSAPrivateKeyStructure((ASN1Sequence) ASN1Sequence.fromByteArray(buffer));
RSAPrivateKeySpec rsaPrivKeySpec = new RSAPrivateKeySpec(asn1PrivKey.getModulus(), asn1PrivKey.getPrivateExponent());
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
this.privateKey = (RSAPrivateKey) keyFactory.generatePrivate(rsaPrivKeySpec);
}
/**
* 从文件中加载私钥
*
* @param keyFileName
* 私钥文件名
* @return 是否成功
* @throws Exception
*/
public void loadPrivateKey(InputStream in) throws Exception {
try {
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String readLine = null;
StringBuilder sb = new StringBuilder();
while ((readLine = br.readLine()) != null) {
if (readLine.charAt(0) == ‘-‘) {
continue;
} else {
sb.append(readLine);
sb.append(‘\r‘);
}
}
loadPrivateKey(sb.toString());
} catch (IOException e) {
throw new Exception("私钥数据读取错误");
} catch (NullPointerException e) {
throw new Exception("私钥输入流为空");
}
}
public void loadPrivateKey(String privateKeyStr) throws Exception {
System.out.println("load-privateKey-PKCS#8");
byte[] buffer = Base64.decodeBase64(privateKeyStr);
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
this.privateKey = (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
}
/**
* @Description: RAS-publicKey-加密
* @author
* @date 2014-11-1
* @time 下午12:00:34
* @param publicKey
* @param plainTextData
* @return 返回字节数组
* @throws Exception
*/
public byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData) throws Exception {
try {
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] enBytes = cipher.doFinal(plainTextData);
return enBytes;
} catch (NoSuchAlgorithmException e) {
throw new Exception("RSA-publicKey-加密异常");
} catch (NoSuchPaddingException e) {
throw new Exception("RSA-publicKey-加密异常");
}
}
/**
* @Description: RAS-publicKey-加密
* @author
* @date 2014-11-1
* @time 下午12:00:55
* @param publicKey
* @param plainTextDataBase64
* 【明文数据-base64编码字符串】
* @return 返回base64编码字符串
* @throws Exception
*/
public String encryptBase64(RSAPublicKey publicKey, String plainTextDataBase64) throws Exception {
byte[] plainTextData = Base64.decodeBase64(plainTextDataBase64);
byte[] enBytes = this.encrypt(publicKey, plainTextData);
return Base64.encodeBase64String(enBytes);
}
/**
* @Description: RSA-privateKey-解密
* @author
* @date 2014-11-1
* @time 下午12:01:31
* @param privateKey
* @param cipherTextData
* @return 返回字节数组
* @throws Exception
*/
public byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherTextData) throws Exception {
try {
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.DECRYPT_MODE, privateKey);
byte[] deBytes = cipher.doFinal(cipherTextData);
return deBytes;
} catch (NoSuchAlgorithmException e) {
throw new Exception("RSA-privateKey-解密异常");
} catch (NoSuchPaddingException e) {
throw new Exception("RSA-privateKey-解密异常");
}
}
/**
* @Description: RSA-privateKey-解密
* @author
* @date 2014-11-1
* @time 下午12:01:57
* @param privateKey
* @param cipherTextDataBase64
* @return 返回base64字符串
* @throws Exception
*/
public String decryptBase64(RSAPrivateKey privateKey, String cipherTextDataBase64) throws Exception {
byte[] cipherTextData = Base64.decodeBase64(cipherTextDataBase64);
byte[] deBytes = this.decrypt(privateKey, cipherTextData);
return Base64.encodeBase64String(deBytes);
}
/**
* @Description: RSA-privateKey-签名
* @author
* @date 2014-11-1
* @time 下午12:07:39
* @param privateKey
* @param content
* @return 返回字节数组
* @throws Exception
*/
public byte[] sign(RSAPrivateKey privateKey, byte[] content) throws Exception {
try {
Signature signature = Signature.getInstance("SHA1WithRSA");
signature.initSign(privateKey);
signature.update(content);
byte[] signResult = signature.sign();
return signResult;
} catch (NoSuchAlgorithmException e) {
throw new Exception("RSA-privateKey-签名异常");
}
}
/**
* @Description: RSA-privateKey-签名
* @author
* @date 2014-11-1
* @time 下午12:09:12
* @param privateKey
* @param contentBase64
* 【验证签名原文-base64编码字符串】
* @return 返回base64字符串
* @throws Exception
*/
public String signBase64(RSAPrivateKey privateKey, String contentBase64) throws Exception {
byte[] content = Base64.decodeBase64(contentBase64);
byte[] signResult = this.sign(privateKey, content);
return Base64.encodeBase64String(signResult);
}
/**
* @Description: RSA-publicKey-验证签名
* @author
* @date 2014-11-1
* @time 下午12:15:52
* @param publicKey
* @param content
* 【签名原文-字节数组】
* @param sign
* 【待验证签名-字节数组】
* @return 签名结果
* @throws Exception
*/
public boolean verify(RSAPublicKey publicKey, byte[] content, byte[] sign) throws Exception {
try {
Signature signature = Signature.getInstance("SHA1WithRSA");
signature.initVerify(publicKey);
signature.update(content);
return signature.verify(sign);
} catch (NoSuchAlgorithmException e) {
throw new Exception("RSA-publicKey-验证签名异常");
}
}
/**
* @Description: RSA-publicKey-验证签名
* @author
* @date 2014-11-1
* @time 下午12:18:52
* @param publicKey
* @param contentBase64
* 【签名原文-base64编码字符串】
* @param signBase64
* 【待验证签名-base64编码字符串】
* @return 签名结果
* @throws Exception
*/
public boolean verifyBase64(RSAPublicKey publicKey, String contentBase64, String signBase64) throws Exception {
byte[] content = Base64.decodeBase64(contentBase64);
byte[] sign = Base64.decodeBase64(signBase64);
return this.verify(publicKey, content, sign);
}
}
参考文献
http://blog.csdn.net/chaijunkun/article/details/7275632
原文：http://my.oschina.net/zj0303/blog/339807