RSA_java代码

接下来我们介绍典型的非对称加密算法——RSARSA这种算法1978年就出现了，它是第一个既能用于数据加密也能用于数字签名的算法。它易于理解和操作，也很流行。算法的名字以发明者的名字命名：RonRivest,AdiShamir和LeonardAdleman。这种加密算法的特点主要是密钥的变化，上文我们看到DES只有一个密钥。相当于只有一把钥匙，如果这把钥匙丢了，数据也就不安全了。RSA同时有两把钥匙，公钥与私钥。同时支持数字签名。数字签名的意义在于，对传输过来的数据进行校验。确保数据在传输工程中不被修改。流程分析：1.甲方构建密钥对儿，将公钥公布给乙方，将私钥保留。2.甲方使用私钥加密数据，然后用私钥对加密后的数据签名，发送给乙方签名以及加密后的数据；乙方使用公钥、签名来验证待解密数据是否有效，如果有效使用公钥对数据解密。3.乙方使用公钥加密数据，向甲方发送经过加密后的数据；甲方获得加密数据，通过私钥解密。importjava.security.Key;importjava.security.KeyFactory;importjava.security.KeyPair;importjava.security.KeyPairGenerator;importjava.security.PrivateKey;importjava.security.PublicKey;importjava.security.Signature;importjava.security.interfaces.RSAPrivateKey;importjava.security.interfaces.RSAPublicKey;importjava.security.spec.PKCS8EncodedKeySpec;importjava.security.spec.X509EncodedKeySpec;importjava.util.HashMap;importjava.util.Map;importjavax.crypto.Cipher;/***RSA安全编码组件**@author梁栋*@version1.0*@since1.0*/publicabstractclassRSACoderextendsCoder{publicstaticfinalStringKEY_ALGORITHM=RSA;publicstaticfinalStringSIGNATURE_ALGORITHM=MD5withRSA;privatestaticfinalStringPUBLIC_KEY=RSAPublicKey;privatestaticfinalStringPRIVATE_KEY=RSAPrivateKey;/***用私钥对信息生成数字签名**@paramdata*加密数据*@paramprivateKey*私钥**@return*@throwsException*/publicstaticStringsign(byte[]data,StringprivateKey)throwsException{//解密由base64编码的私钥byte[]keyBytes=decryptBASE64(privateKey);//构造PKCS8EncodedKeySpec对象PKCS8EncodedKeySpecpkcs8KeySpec=newPKCS8EncodedKeySpec(keyBytes);//KEY_ALGORITHM指定的加密算法KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);//取私钥匙对象PrivateKeypriKey=keyFactory.generatePrivate(pkcs8KeySpec);//用私钥对信息生成数字签名Signaturesignature=Signature.getInstance(SIGNATURE_ALGORITHM);signature.initSign(priKey);signature.update(data);returnencryptBASE64(signature.sign());}/***校验数字签名**@paramdata*加密数据*@parampublicKey*公钥*@paramsign*数字签名**@return校验成功返回true失败返回false*@throwsException**/publicstaticbooleanverify(byte[]data,StringpublicKey,Stringsign)throwsException{//解密由base64编码的公钥byte[]keyBytes=decryptBASE64(publicKey);//构造X509EncodedKeySpec对象X509EncodedKeySpeckeySpec=newX509EncodedKeySpec(keyBytes);//KEY_ALGORITHM指定的加密算法KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);//取公钥匙对象PublicKeypubKey=keyFactory.generatePublic(keySpec);Signaturesignature=Signature.getInstance(SIGNATURE_ALGORITHM);signature.initVerify(pubKey);signature.update(data);//验证签名是否正常returnsignature.verify(decryptBASE64(sign));}/***解密br*用私钥解密**@paramdata*@paramkey*@return*@throwsException*/publicstaticbyte[]decryptByPrivateKey(byte[]data,Stringkey)throwsException{//对密钥解密byte[]keyBytes=decryptBASE64(key);//取得私钥PKCS8EncodedKeySpecpkcs8KeySpec=newPKCS8EncodedKeySpec(keyBytes);KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);KeyprivateKey=keyFactory.generatePrivate(pkcs8KeySpec);//对数据解密Ciphercipher=Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.DECRYPT_MODE,privateKey);returncipher.doFinal(data);}/***解密br*用公钥解密**@paramdata*@paramkey*@return*@throwsException*/publicstaticbyte[]decryptByPublicKey(byte[]data,Stringkey)throwsException{//对密钥解密byte[]keyBytes=decryptBASE64(key);//取得公钥X509EncodedKeySpecx509KeySpec=newX509EncodedKeySpec(keyBytes);KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);KeypublicKey=keyFactory.generatePublic(x509KeySpec);//对数据解密Ciphercipher=Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.DECRYPT_MODE,publicKey);returncipher.doFinal(data);}/***加密br*用公钥加密**@paramdata*@paramkey*@return*@throwsException*/publicstaticbyte[]encryptByPublicKey(byte[]data,Stringkey)throwsException{//对公钥解密byte[]keyBytes=decryptBASE64(key);//取得公钥X509EncodedKeySpecx509KeySpec=newX509EncodedKeySpec(keyBytes);KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);KeypublicKey=keyFactory.generatePublic(x509KeySpec);//对数据加密Ciphercipher=Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.ENCRYPT_MODE,publicKey);returncipher.doFinal(data);}/***加密br*用私钥加密**@paramdata*@paramkey*@return*@throwsException*/publicstaticbyte[]encryptByPrivateKey(byte[]data,Stringkey)throwsException{//对密钥解密byte[]keyBytes=decryptBASE64(key);//取得私钥PKCS8EncodedKeySpecpkcs8KeySpec=newPKCS8EncodedKeySpec(keyBytes);KeyFactorykeyFactory=KeyFactory.getInstance(KEY_ALGORITHM);KeyprivateKey=keyFactory.generatePrivate(pkcs8KeySpec);//对数据加密Ciphercipher=Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.ENCRYPT_MODE,privateKey);returncipher.doFinal(data);}/***取得私钥**@paramkeyMap*@return*@throwsException*/publicstaticStringgetPrivateKey(MapString,ObjectkeyMap)throwsException{Keykey=(Key)keyMap.get(PRIVATE_KEY);returnencryptBASE64(key.getEncoded());}/***取得公钥**@paramkeyMap*@return*@throwsException*/publicstaticStringgetPublicKey(MapString,ObjectkeyMap)throwsException{Keykey=(Key)keyMap.get(PUBLIC_KEY);returnencryptBASE64(key.getEncoded());}/***初始化密钥**@return*@throwsException*/publicstaticMapString,ObjectinitKey()throwsException{KeyPairGeneratorkeyPairGen=KeyPairGenerator.getInstance(KEY_ALGORITHM);keyPairGen.initialize(1024);KeyPairkeyPair=keyPairGen