之前发了一篇"TripleDes的加解密Java、C#、php通用代码"，后面又有项目用到了Rsa加解密，还是在不同系统之间进行交互，Rsa在不同语言的密钥格式不一样，所以过程中主要还是密钥转换问题，为方便密钥转换，写了一个XML和PEM格式的密钥转换工具，文章后面会提供密钥转换工具的下载地址，通过搜索参考和研究终于搞定了在Java、C#和Php都可以通用的加解密代码，整理了Rsa的加解密代码做个记录，以后可以参考，大家应该都知道Rsa算法，这里就不说明了，直接看代码（代码主要是公钥加密私钥解密，密文统一进行base64编码，密钥长度为2048）：
Java版本：
package com.jaamy.common.util; import java.io.BufferedReader; import java.io.ByteArrayOutputStream; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.security.Key; import java.security.KeyFactory; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; import javax.crypto.Cipher; import org.apache.commons.codec.binary.Base64; public class RSACryptoUtil { /** * 加密算法RSA */ public static final String KEY_ALGORITHM = "RSA"; /** * 填充方式 */ public static final String CIPHER_TRANSFORMAT = "RSA/ECB/PKCS1Padding"; /** * RSA最大加密明文大小 */ private static final int MAX_ENCRYPT_BLOCK = 245; /** * RSA最大解密密文大小 */ private static final int MAX_DECRYPT_BLOCK = 256; /** * 公钥加密 * @param content 原文 * @param publicKey 公钥 * @param inputCharset 字符编码 * @return 加密后的字符串（base64） * @throws Exception */ public static String encryptByPublicKey(String content, String publicKey, String inputCharset) throws Exception { byte[] data = content.getBytes(inputCharset); byte[] keyBytes = Base64.decodeBase64(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(CIPHER_TRANSFORMAT); 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 Base64.encodeBase64String(encryptedData); } /** * 私钥解密 * @param content 密文（base64） * @param privateKey 私钥 * @param inputCharset 字符编码 * @return * @throws Exception */ public static String decryptByPrivateKey(String content, String privateKey, String inputCharset) throws Exception { byte[] encryptedData = Base64.decodeBase64(content); byte[] keyBytes = Base64.decodeBase64(privateKey); PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key privateK = keyFactory.generatePrivate(pkcs8KeySpec); Cipher cipher = Cipher.getInstance(CIPHER_TRANSFORMAT); 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 new String(decryptedData, inputCharset); } /** * 从文件中加载密钥字符串 * @return 是否成功 * @throws Exception */ public static String loadKeyString(String keyFile){ String keyString=""; InputStream in=null; BufferedReader br=null; try { in=RSACryptoUtil.class.getResourceAsStream("/"+keyFile); 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'); } } keyString=sb.toString(); } catch (IOException e) { } catch (Exception e) { }finally{ if(br!=null){ try { br.close(); } catch (IOException e) { } } if(in!=null){ try { in.close(); } catch (IOException e) { } } } return keyString; } /** * 从文件中加载密钥字符串 根据文件路径加载 * @return 是否成功 * @throws Exception */ public static String loadKeyStringByPath(String keyFile){ String keyString=""; InputStream in=null; BufferedReader br=null; try { in = new FileInputStream(keyFile); 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'); } } keyString=sb.toString(); } catch (IOException e) { System.out.println(e.getMessage()); } catch (Exception e) { System.out.println(e.getMessage()); }finally{ if(br!=null){ try { br.close(); } catch (IOException e) { } } if(in!=null){ try { in.close(); } catch (IOException e) { } } } return keyString; } public static void main(String[] args) throws Exception { String publicKey = RSAUtils.loadKeyStringByPath("D:/sso_public_key_test.pem"); System.out.println(RSACryptoUtil.encryptByPublicKey("123", publicKey, "utf-8")); } }
C#版本：
/// <summary> /// RSA加密+base64 /// </summary> /// <param name="publickey">公钥</param> /// <param name="content">原文</param> /// <returns>加密后的密文字符串</returns> public static string RSAEncrypt(string publickey, string content) { //最大文件加密块 int MAX_ENCRYPT_BLOCK = 245; RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(); byte[] cipherbytes; rsa.FromXmlString(publickey); byte[] contentByte = Encoding.UTF8.GetBytes(content); int inputLen = contentByte.Length; int offSet = 0; byte[] cache; int i = 0; System.IO.MemoryStream aMS = new System.IO.MemoryStream(); // 对数据分段加密 while (inputLen - offSet > 0) { byte[] temp = new byte[MAX_ENCRYPT_BLOCK]; if (inputLen - offSet > MAX_ENCRYPT_BLOCK) { Array.Copy(contentByte, offSet, temp, 0, MAX_ENCRYPT_BLOCK); cache = rsa.Encrypt(Encoding.UTF8.GetBytes(content), false); } else { Array.Copy(contentByte, offSet, temp, 0, inputLen - offSet); cache = rsa.Encrypt(Encoding.UTF8.GetBytes(content), false); } aMS.Write(cache, 0, cache.Length); i++; offSet = i * MAX_ENCRYPT_BLOCK; } cipherbytes = aMS.ToArray(); return Convert.ToBase64String(cipherbytes); } /// <summary> /// RSA解密 /// </summary> /// <param name="privatekey">私钥</param> /// <param name="content">密文（RSA+base64）</param> /// <returns>解密后的字符串</returns> public static string RSADecrypt(string privatekey, string content) { //最大文件解密块 int MAX_DECRYPT_BLOCK = 256; RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(); byte[] cipherbytes; rsa.FromXmlString(privatekey); byte[] contentByte = Convert.FromBase64String(content); int inputLen = contentByte.Length; // 对数据分段解密 int offSet = 0; int i = 0; byte[] cache; System.IO.MemoryStream aMS = new System.IO.MemoryStream(); while (inputLen - offSet > 0) { byte[] temp = new byte[MAX_DECRYPT_BLOCK]; if (inputLen - offSet > MAX_DECRYPT_BLOCK) { Array.Copy(contentByte, offSet, temp, 0, MAX_DECRYPT_BLOCK); cache = rsa.Decrypt(temp, false); } else { Array.Copy(contentByte, offSet, temp, 0, inputLen - offSet); cache = rsa.Decrypt(temp, false); } aMS.Write(cache, 0, cache.Length); i++; offSet = i * MAX_DECRYPT_BLOCK; } cipherbytes = aMS.ToArray(); return Encoding.UTF8.GetString(cipherbytes); }
Php版本：
<?php #私钥 $private_key = '-----BEGIN PRIVATE KEY----- MIIEvwIBADANBgkqhkiG9w0BAQEFAASCBKkwggSlAgEAAoIBAQCocmvQIWD2L9TW N1uKpLONwHcdy2oaKoW1CtI8PB+S+UjdEuLl3usWEuh3ZgLYloPyD9553SJFn7an fOplHITBqASOIXt9pi0CkahUPgwCPj4Dke5cT3fsp2i243/FX3afzrcf7FfTrEv/ LT22wF3csqrGt/UhqMcmpWIpPaL8edoCwGRBhghzEWaRwPZ2x5RPg+9qTSy0M7QG u+8EwYDnNkGGuuIwzNxklclic9Unp96eVp33vOP/LNvz90OcuqGQQcABh+e2ttv6 VzqlRcD1GRhxqkT3erXmgbQAVm6JQHArK1Up10No+lth1tri5TGcL0BEF7PetDIj jYh+aCLpAgMBAAECggEAPjFI1yaLyzmrxo/Xz5+x36NxF2IUQabziP1+09iK+9Po cB9aAO9GMvc2N2dFo7wm6Uesp6fa0IQAh2RakoxuA6ZKUEPSeXjSY4Ft+fSSsH1U njLSI+j/aTQCOIxUj4YIoUZMXJABeVjDEmscvw3VWffpj8c5zXyoUv9696kXNUoa uHOuphe1UNc3ghFIpWK+7ScxkPB6KtmAFwD4LSbT9OwhPozavBqouQvhLt1bXO8C ycKq4f1Pzhtt3sq3BRsPwqGhWt1NK95upKQuDnk1kJHjNzScH1FZxhsBHLxwOJ6E M7HP5Ywh78umusaNPVLMM6+YVWbENg+WZZcXd/XspQKBgQDRIhIukY7m7fRBH0CP mHi20gUmn7HzXgLxlbcU5n2PMDHHOg8D+Nmz1MnYPRQNwqxJdH8HOk8YQDC2uA+h BpyCpvPbp6y6SnZw8bhqiNfSHBjEftmg7lUU5xzBiBo6SyCyLkWD2xa/O8Vyh6ut /G1mQpNNJWWt5b+g5c4i0/fIhwKBgQDOMjGcLS8zHnZ30ZsWUS39iZ5TZXPCldTl Q9JB5PnB4CajYmQEdw3n9C6mOO42b+3M04mmqo1r0HiNyA9lZQQNsM3KqG+ngGvE 0DM1cAyuz3Fi3XTIhAbRyXXyVbqBp5Yh2/O2lvrsInusJrimDRgwglquu2GsdVrj +++b2DFFDwKBgQCkfXLlk/FdK44xZn5mM1vHGBubDIJv0+Lm14Yf90aMyDBu7fh/ fEznSBfWb/wE8riGMg3zxmYNwfdO0Cji04torB4kB5cxE35jSYxupuFxzk2gx9Eu 5iafgUQ56G4QqaS24PQmSL10fnPHqHRdLa1ygCzRwfdettVpnTbsZ+J9owKBgQDF o2Tb3o9sPxmsdVNiy8L6TstcAlU3wOfELQK+uFwQ0eoXFvrpMLg6iVmhZ9YkhZp4 hpZdEwLkwXib5ZOkS3PcL4jBZDtJYRVrG2jKIrF1aU60RbJnc+0ZbjHIaxWOqvSD VdE/RW4TomXKN38rYke6T2feLatMY1wQRG6BgXKQTwKBgQDKfK9Xuqzx+WI4AohT EwKrQEZUMD+6DTESHHG9As4zMJ9zU+6iPpM4Gw4CzfJZHhPP4dD+TC9NcvvR+GC9 UkwxmZrvP1+6KNFp0DZNk6M9wPZuYM/E63Vy0sFEA+/gFp4vQh8k7N8n/n7DhR3v kLuPdicfsKcz0thxzyDjv6oR2g== -----END PRIVATE KEY-----'; #公钥 $public_key = '-----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAqHJr0CFg9i/U1jdbiqSz jcB3HctqGiqFtQrSPDwfkvlI3RLi5d7rFhLod2YC2JaD8g/eed0iRZ+2p3zqZRyE wagEjiF7faYtApGoVD4MAj4+A5HuXE937KdotuN/xV92n863H+xX06xL/y09tsBd 3LKqxrf1IajHJqViKT2i/HnaAsBkQYYIcxFmkcD2dseUT4Pvak0stDO0BrvvBMGA 5zZBhrriMMzcZJXJYnPVJ6fenlad97zj/yzb8/dDnLqhkEHAAYfntrbb+lc6pUXA 9RkYcapE93q15oG0AFZuiUBwKytVKddDaPpbYdba4uUxnC9ARBez3rQyI42Ifmgi 6QIDAQAB -----END PUBLIC KEY-----'; $pi_key = openssl_pkey_get_private($private_key); $pu_key = openssl_pkey_get_public($public_key); #公钥加密数据 rsa+base64 $data = "hello world!"; openssl_public_encrypt($data,$encrypted,$pu_key); $base64_encrypted = base64_encode($encrypted); echo $base64_encrypted."\n"; #私钥解密数据 openssl_private_decrypt(base64_decode($base64_encrypted),$decrypted_data,$pi_key); echo $decrypted_data; ?>
Rsa加解密C#和Java、php使用的密钥格式不一样，这里提供一个密钥转换工具：Rsa密钥转换工具v2.0.zip
