package xin.glue.cargocnHttpClient;

import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.security.Key;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;

public class RSAUtils {
	/**
	 * 加密算法RSA
	 */
	public static final String KEY_ALGORITHM = "RSA";

	/**
	 * 签名算法
	 */
	public static final String SIGNATURE_ALGORITHM = "SHA1WithRSA";

	/**
	 * RSA最大加密明文大小
	 */
	private static final int MAX_ENCRYPT_BLOCK = 117;

	/**
	 * RSA最大解密密文大小
	 */
	private static final int MAX_DECRYPT_BLOCK = 128;

	/**
	 * <p>
	 * 用私钥对信息生成数字签名
	 * </p>
	 * 
	 * @param data
	 *            已加密数据
	 * @param privateKey
	 *            私钥(BASE64编码)
	 * 
	 * @return
	 * @throws Exception
	 */
	public static String sign(byte[] data, String privateKey) throws Exception {
		byte[] keyBytes = Base64.decode(privateKey);
		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
		signature.initSign(privateK);
		signature.update(data);
		return Base64.encode(signature.sign());
	}

	/** */
	/**
	 * <p>
	 * 校验数字签名
	 * </p>
	 * 
	 * @param data
	 *            已加密数据
	 * @param publicKey
	 *            公钥(BASE64编码)
	 * @param sign
	 *            数字签名
	 * 
	 * @return
	 * @throws Exception
	 * 
	 */
	public static boolean verify(byte[] data, String publicKey, String sign)
			throws Exception {
		byte[] keyBytes = Base64.decode(publicKey);
		X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		PublicKey publicK = keyFactory.generatePublic(keySpec);
		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
		signature.initVerify(publicK);
		signature.update(data);
		return signature.verify(Base64.decode(sign));
	}

	/** */
	/**
	 * <P>
	 * 私钥解密
	 * </p>
	 * 
	 * @param encryptedData
	 *            已加密数据
	 * @param privateKey
	 *            私钥(BASE64编码)
	 * @return
	 * @throws Exception
	 */
	public static byte[] decryptByPrivateKey(byte[] encryptedData,
			String privateKey) throws Exception {
		byte[] keyBytes = Base64.decode(privateKey);
		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
		cipher.init(Cipher.DECRYPT_MODE, privateK);
		int inputLen = encryptedData.length;
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		int offSet = 0;
		byte[] cache;
		int i = 0;
		// 对数据分段解密
		while (inputLen - offSet > 0) {
			if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
				cache = cipher
						.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
			} else {
				cache = cipher
						.doFinal(encryptedData, offSet, inputLen - offSet);
			}
			out.write(cache, 0, cache.length);
			i++;
			offSet = i * MAX_DECRYPT_BLOCK;
		}
		byte[] decryptedData = out.toByteArray();
		out.close();
		return decryptedData;
	}

	/** */
	/**
	 * <p>
	 * 公钥解密
	 * </p>
	 * 
	 * @param encryptedData
	 *            已加密数据
	 * @param publicKey
	 *            公钥(BASE64编码)
	 * @return
	 * @throws Exception
	 */
	public static byte[] decryptByPublicKey(byte[] encryptedData,
			String publicKey) throws Exception {
		byte[] keyBytes = Base64.decode(publicKey);
		X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		Key publicK = keyFactory.generatePublic(x509KeySpec);
		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
		cipher.init(Cipher.DECRYPT_MODE, publicK);
		int inputLen = encryptedData.length;
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		int offSet = 0;
		byte[] cache;
		int i = 0;
		// 对数据分段解密
		while (inputLen - offSet > 0) {
			if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
				cache = cipher
						.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
			} else {
				cache = cipher
						.doFinal(encryptedData, offSet, inputLen - offSet);
			}
			out.write(cache, 0, cache.length);
			i++;
			offSet = i * MAX_DECRYPT_BLOCK;
		}
		byte[] decryptedData = out.toByteArray();
		out.close();
		return decryptedData;
	}

	/** */
	/**
	 * <p>
	 * 公钥加密
	 * </p>
	 * @param data  源数据
	 * @param publicKey  公钥(BASE64编码)
	 * @return
	 * @throws Exception
	 */
	public static byte[] encryptByPublicKey(byte[] data, String publicKey)
			throws Exception {
		byte[] keyBytes = Base64.decode(publicKey);
		X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		Key publicK = keyFactory.generatePublic(x509KeySpec);
		// 对数据加密
		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
		cipher.init(Cipher.ENCRYPT_MODE, publicK);
		int inputLen = data.length;
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		int offSet = 0;
		byte[] cache;
		int i = 0;
		// 对数据分段加密
		while (inputLen - offSet > 0) {
			if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
				cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
			} else {
				cache = cipher.doFinal(data, offSet, inputLen - offSet);
			}
			out.write(cache, 0, cache.length);
			i++;
			offSet = i * MAX_ENCRYPT_BLOCK;
		}
		byte[] encryptedData = out.toByteArray();
		out.close();
		return encryptedData;
	}

	/** */
	/**
	 * <p>
	 * 私钥加密
	 * </p>
	 * @param data  源数据
	 * @param privateKey  私钥(BASE64编码)
	 * @return
	 * @throws Exception
	 */
	public static byte[] encryptByPrivateKey(byte[] data, String privateKey)
			throws Exception {
		byte[] keyBytes = Base64.decode(privateKey);
		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
		cipher.init(Cipher.ENCRYPT_MODE, privateK);
		int inputLen = data.length;
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		int offSet = 0;
		byte[] cache;
		int i = 0;
		// 对数据分段加密
		while (inputLen - offSet > 0) {
			if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
				cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
			} else {
				cache = cipher.doFinal(data, offSet, inputLen - offSet);
			}
			out.write(cache, 0, cache.length);
			i++;
			offSet = i * MAX_ENCRYPT_BLOCK;
		}
		byte[] encryptedData = out.toByteArray();
		out.close();
		return encryptedData;
	}

	/**
	 * 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 static String loadPublicKeyByFile(String path) throws Exception {
		try {
			path = java.net.URLDecoder.decode(path,"utf-8");  
			BufferedReader br = new BufferedReader(new FileReader(path));
			String readLine = null;
			StringBuilder sb = new StringBuilder();
			while ((readLine = br.readLine()) != null) {
				sb.append(readLine);
			}
			br.close();
			return getPem("PUBLIC KEY", 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");
		}
	}
	/**
	 * 从文件中输入流中加载公钥
	 * @param path = "PUB" 为公钥，"PRI"为私钥 公钥输入流
	 * @throws Exception 加载公钥时产生的异常
	 */
	public static String loadKeyStr(String path) throws Exception {
		/*
			 -----BEGIN PUBLIC KEY-----
			MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC7vWJpbaQloLmi1nf0v90Sk1TZ
			WvPEl4aXuSTGbnw6FTaF/Mf4Gcvj59a+j/dE/ZsAo8WRh7g3qviBZ78tdsJn+Nvi
			9H9KZhAuMSFbob82mMD2aiASnbEl3uE4hdlYoj59nWiX6W7APnMOuUyZ2u8z5AwI
			wt1/4+9XAvZ3cNOA2wIDAQAB
			-----END PUBLIC KEY-----
		 */
		/*
			-----BEGIN PRIVATE KEY-----
			MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBALGn68OHTm3Ewe08
			nYvyQUI7naTf9af3FEe4yikFlgsPTAKDXX1hrGfS1Amk2wVBiAjEfmlghqi557JB
			obeiTlXGMUF0ATLoXWKMdKMFZK3IcG/8hauQhW2l5RUiSN+4Qf38XP/yT3eoLvxA
			82+AzFrpuF4pR6UvjFo4eY7qlv2FAgMBAAECgYAvGCGSkqLCzH7QAdqNx6lvAli2
			5Tu8y+3PWXgVycpNoj93BxXYb/UBDM1yxQXebdG+6T/NdW4c+jMmeOmCwX7cItgH
			UgLmfEqF3PE/U7oIunNh2Q3wbqkljnh9Df7NTapu/6eOn4vhFdQRYJalM7FM5oZc
			9UETRESXoUqgKc/KIQJBAOBu1zQu0d5Sg+CIVZ6YWbm1NvdvtqPPyGjXBItIotRT
			128LLnEnd2OV5D1+l+uR+xPkozs5O/puOifN5w+9gu0CQQDKpMeN0Ed/8O7b6jxD
			uOo8FepXLjCBlq7WQmXIjv22W3LlOTS7Xmy5wf8dlQcORdg2U3cX4AueAdHhVhg4
			r5n5AkALymbt6+PErUsWWbM90L0t/3Iyz6ClvH3H3Dv14UwEoZ74y3qWIT+pcK97
			95Gdo56wLdvRebFH99CAVNXlwswFAkAXtCKrkftrGdG247Vc7ppnoOCihgKihe+5
			nFavmRpQZG4SJhjm+eqZ5/lhinci0kSyRh0eK9TwDKJyS1HV/6RxAkEA3mZizaTs
			9ppt9lXYhLudK6e1ryqFOdDg2wkWA5oUYZ0IDdM7z9jEkR0ya1keUIkTJCkegLrI
			RSSPXymOqTGfaA==
			-----END PRIVATE KEY----- 
		 */
		StringBuilder sb = new StringBuilder();
		if("PUB".equals(path)) {
			sb.append("-----BEGIN PUBLIC KEY-----");
			sb.append("MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC7vWJpbaQloLmi1nf0v90Sk1TZ");
			sb.append("WvPEl4aXuSTGbnw6FTaF/Mf4Gcvj59a+j/dE/ZsAo8WRh7g3qviBZ78tdsJn+Nvi");
			sb.append("9H9KZhAuMSFbob82mMD2aiASnbEl3uE4hdlYoj59nWiX6W7APnMOuUyZ2u8z5AwI");
			sb.append("wt1/4+9XAvZ3cNOA2wIDAQAB");
			sb.append("-----END PUBLIC KEY-----");
			return getPem("PUBLIC KEY", sb.toString());
		} else {
			sb.append("-----BEGIN PRIVATE KEY-----");
			sb.append("MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBALGn68OHTm3Ewe08");
			sb.append("nYvyQUI7naTf9af3FEe4yikFlgsPTAKDXX1hrGfS1Amk2wVBiAjEfmlghqi557JB");
			sb.append("obeiTlXGMUF0ATLoXWKMdKMFZK3IcG/8hauQhW2l5RUiSN+4Qf38XP/yT3eoLvxA");
			sb.append("82+AzFrpuF4pR6UvjFo4eY7qlv2FAgMBAAECgYAvGCGSkqLCzH7QAdqNx6lvAli2");
			sb.append("5Tu8y+3PWXgVycpNoj93BxXYb/UBDM1yxQXebdG+6T/NdW4c+jMmeOmCwX7cItgH");
			sb.append("UgLmfEqF3PE/U7oIunNh2Q3wbqkljnh9Df7NTapu/6eOn4vhFdQRYJalM7FM5oZc");
			sb.append("9UETRESXoUqgKc/KIQJBAOBu1zQu0d5Sg+CIVZ6YWbm1NvdvtqPPyGjXBItIotRT");
			sb.append("128LLnEnd2OV5D1+l+uR+xPkozs5O/puOifN5w+9gu0CQQDKpMeN0Ed/8O7b6jxD");
			sb.append("uOo8FepXLjCBlq7WQmXIjv22W3LlOTS7Xmy5wf8dlQcORdg2U3cX4AueAdHhVhg4");
			sb.append("r5n5AkALymbt6+PErUsWWbM90L0t/3Iyz6ClvH3H3Dv14UwEoZ74y3qWIT+pcK97");
			sb.append("95Gdo56wLdvRebFH99CAVNXlwswFAkAXtCKrkftrGdG247Vc7ppnoOCihgKihe+5");
			sb.append("nFavmRpQZG4SJhjm+eqZ5/lhinci0kSyRh0eK9TwDKJyS1HV/6RxAkEA3mZizaTs");
			sb.append("9ppt9lXYhLudK6e1ryqFOdDg2wkWA5oUYZ0IDdM7z9jEkR0ya1keUIkTJCkegLrI");
			sb.append("RSSPXymOqTGfaA==");
			sb.append("-----END PRIVATE KEY----- ");
			return getPem("PRIVATE KEY", sb.toString());
		}
	}

	/**
	 * 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 static RSAPublicKey loadPublicKeyByStr(String publicKeyStr)
			throws Exception {
		try {
			byte[] buffer = Base64.decode(publicKeyStr);
			KeyFactory keyFactory = KeyFactory.getInstance("RSA");
			X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
			return (RSAPublicKey) keyFactory.generatePublic(keySpec);
		} catch (NoSuchAlgorithmException e) {
			throw new Exception("无此算法");
		} catch (InvalidKeySpecException e) {
			throw new Exception("公钥非法");
		} catch (NullPointerException e) {
			e.printStackTrace();
			throw new Exception("公钥数据为空");
		}
	}

	private static String getPem(String type, String keyStr) {
		String header = "-----BEGIN " + type + "-----\\n";
		String footer = "-----END " + type + "-----";
		int start = keyStr.indexOf(header) + header.length() - 1;
		int end = keyStr.indexOf(footer, start);
		return keyStr.substring(start, end);
	}

	/**
	 * 从文件中加载私钥
	 * 
	 * @param keyFileName
	 *            私钥文件名
	 * @return 是否成功
	 * @throws Exception
	 */
	public static String loadPrivateKeyByFile(String path) throws Exception {
		try {
			path = java.net.URLDecoder.decode(path,"utf-8");  
			BufferedReader br = new BufferedReader(new FileReader(path));
			String readLine = null;
			StringBuilder sb = new StringBuilder();
			while ((readLine = br.readLine()) != null) {
				sb.append(readLine);
			}
			br.close();
			return getPem("PRIVATE KEY", 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 static RSAPrivateKey loadPrivateKeyByStr(String privateKeyStr)
			throws Exception {
		try {
			byte[] buffer = Base64.decode(privateKeyStr);
			PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
			KeyFactory keyFactory = KeyFactory.getInstance("RSA");
			return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
		} catch (NoSuchAlgorithmException e) {
			throw new Exception("无此算法");
		} catch (InvalidKeySpecException e) {
			throw new Exception("私钥非法");
		} catch (NullPointerException e) {
			throw new Exception("私钥数据为空");
		}
	}

 
}