Java加解密學習

柯克霍夫原則：資料的安全基於金鑰而不是演算法的保密。即系統的安全取決於金鑰，對金鑰保密，對演算法公開。——現代密碼學設計的基本原則。

演算法實現分為3類：jdk，common codes(cc)，bouncy castle(bc)，後兩者使用需要引入jar包。

1.jdk實現

base64encoder encoder = new base64encoder();

string encode = encoder.encode(src.getbytes());
system.out
.println("jdk encode:"+encode);
base64decoder decoder = new base64decoder();
system.out
.println("jdk decode:"+new string(decoder.decodebuffer(encode)));

byte encodebytes = base64.encodebase64(src.getbytes());

system.out
.println("cc encode:"+new string(encodebytes));
system.out
.println("cc decode:"+new string(base64.decodebase64(encodebytes)));

byte encodebytes = org.bouncycastle

.util
.encoders
.base64.encode(src.getbytes());
byte decodebytes = org.bouncycastle
.util
.encoders
.base64.decode(encodebytes);

messagedigest md = messagedigest.getinstance("md5");

byte mdbytes = md.digest(src.getbytes());
system.out
.println("jdk md5:"+hex.encodehexstring(mdbytes));

2.cc實現

system.out

.println("cc md5:"+digestutils.md5hex(src.getbytes()));

digest digest = new md5digest();

digest.update(src.getbytes(),0,src.getbytes().length);
byte mdbytes = new byte[digest.getdigestsize()];
digest.dofinal(mdbytes,0);
system.out
.println("bc md5:"+org.bouncycastle
.util
.encoders
.base64.hex
.tohexstring(mybytes));

sha演算法實現與md實現很相似

1.jdk實現

messagedigest md = messagedigest.getinstance("sha");

byte mdbytes = md.digest(src.getbytes());
system.out
.println("jdk sha1:"+hex.encodehexstring(mdbytes));

system.out

.println("cc sha1:"+digestutils.sha1hex(src.getbytes()));

digest digest = new sha1digest();

digest.update(src.getbytes(),0,src.getbytes().length);
byte mdbytes = new byte[digest.getdigestsize()];
digest.dofinal(mdbytes,0);
system.out
.println("bc sha1:"+org.bouncycastle
.util
.encoders
.base64.hex
.tohexstring(mybytes));

keygennerator kg = keygenerator.getinstance("hmacmd5");

secretkey sk = kg.generatekey();//產生金鑰
//bytekey = sk.getencoded(); //獲得金鑰，隨機
bytekey = hex.decodehex(new
char);//獲得金鑰，自定義
secretkey rsk = new secretkeyspec(key, "hmacmd5");//還原金鑰
mac mac = mac.getinstance(rsk.getalgorithm());//例項化mac
mac.init(rsk);
byte hmacmd5bytes = mac.dofinal(src.getbytes());//執行摘要
system.out.println("jdk hamcmd5:"+hex.encodehexstring(hmacmd5bytes));

加解密方法

imports system imports system.security.cryptography imports system.text imports system.io public class encryptor private shared iv as byte private sha...

加解密簡介

加密技術，簽名技術的需要做到三防一確認。一防竊聽，二防篡改，三防抵賴，確認對方身份。在電子商務過程中，開始時必須確認對方身份，不然談了半天，發現網際網路那頭真是一條狗，就悲劇了。防竊聽是指，即便有人在網路傳輸過程中得到了資料，看到的也是亂七八糟，無法從中得知正常的資訊。舉個例子，談判前老總通過網路跟...

字元加解密

using system using system.security.cryptography using system.web.security using system.io using system.text using system.configuration namespace x.com...