1. md5加密,常用于加密用户名密码,当用户验证时。} } 2. sha加密,与md5相似的用法,只是两者的算法不同。} } 3. rsa加密,ras加密允许解密。常用于文本内容的加密。
1. md5加密,常用于加密用户名密码,当用户验证时。
protected byte[] encrypt(byte[] obj) ...{ try ...{ messagedigest md5 = messagedigest.getinstance("md5"); md5.update(obj); return md5.digest(); } catch (nosuchalgorithmexception e) ...{ e.printstacktrace(); } } |
protected byte[] encrypt(byte[] obj) ...{ try ...{ messagedigest sha = messagedigest.getinstance("sha"); sha.update(obj); return sha.digest(); } catch (nosuchalgorithmexception e) ...{ e.printstacktrace(); } } |
import java.security.keypair; import java.security.keypairgenerator; import java.security.interfaces.rsaprivatekey; import java.security.interfaces.rsapublickey; import javax.crypto.cipher; /** *//** * rsaencrypt * * @author maqujun * @see */ public class rsaencrypt ...{ /** *//** * main method for rsaencrypt. * @param args */ public static void main(string[] args) ...{ try ...{ rsaencrypt encrypt = new rsaencrypt(); string encrypttext = "encrypttext"; keypairgenerator keypairgen = keypairgenerator.getinstance("rsa"); keypairgen.initialize(1024); keypair keypair = keypairgen.generatekeypair(); // generate keys rsaprivatekey privatekey = (rsaprivatekey) keypair.getprivate(); rsapublickey publickey = (rsapublickey) keypair.getpublic(); byte[] e = encrypt.encrypt(publickey, encrypttext.getbytes()); byte[] de = encrypt.decrypt(privatekey,e); system.out.println(encrypt.bytestostring(e)); system.out.println(encrypt.bytestostring(de)); } catch (exception e) ...{ e.printstacktrace(); } } /** *//** * change byte array to string. * @return byte[] */ protected string bytestostring(byte[] encrytpbyte) ...{ string result = ""; for (byte bytes : encrytpbyte) ...{ result += (char) bytes.intvalue(); } return result; } /** *//** * encrypt string. * @return byte[] */ protected byte[] encrypt(rsapublickey publickey, byte[] obj) ...{ if (publickey != null) ...{ try ...{ cipher cipher = cipher.getinstance("rsa"); cipher.init(cipher.encrypt_mode, publickey); return cipher.dofinal(obj); } catch (exception e) ...{ e.printstacktrace(); } } return null; } /** *//** * basic decrypt method * @return byte[] */ protected byte[] decrypt(rsaprivatekey privatekey, byte[] obj) ...{ if (privatekey != null) ...{ try ...{ cipher cipher = cipher.getinstance("rsa"); cipher.init(cipher.decrypt_mode, privatekey); return cipher.dofinal(obj); } catch (exception e) ...{ e.printstacktrace(); } } return null; } } |