JSフロント暗号化、JAVAバックグラウンド復号を用いたRSA実装について、RSA暗号化と署名


実装:
RSA非対称暗号化方式で実現した.バックグラウンドでrsa鍵ペアを生成し、ログインページにrsa公開鍵を設定し、コミット時に公開鍵でパスワードを暗号化し、生成した秘密文をバックグラウンドに転送し、秘密鍵で復号し、パスワード明文を取得する.
このようにクライアントはrsa暗号化方式と公開鍵を知るだけで、フロントは秘密鍵が復号できないことを知らないが、この解決策は比較的安全である.
添付ファイルはネットユーザーの資料を参照するjava+JSの実現で、ここに置いて皆さんにダウンロードしてもらいます.アクセス方法/RSA/login.jsp.
必要なhttp://www.bouncycastle.orgbcprov-jdk 14-123.jarファイルをダウンロードします.
バックグラウンドをbigintに変換するため、明文の長さに制限があります.
合計長さは126を超えない(1漢字長は9).次の2つの文字列があります.
阿送大法散得阿送大法散得阿送12321321323123123123223131232 K 1232132132312312322312312312322323123123123123123223232 K 123213213231231231231231231231232231231231232231231232 K 12345678901234567789012
 
 
RSA速度   * いずれも大数計算を行っているため、RSAが最も速い場合もDESより100倍遅く、ソフトウェアでもハードウェアでも実現されます.   * 速度はずっとRSAの欠陥です.一般的には、少量のデータ暗号化にのみ使用されます.
 
 
Util.java
    package RSA;  
      
    /** 
     *  
     */  
      
    import java.io.ByteArrayOutputStream;  
    import java.io.FileInputStream;  
    import java.io.FileOutputStream;  
    import java.io.ObjectInputStream;  
    import java.io.ObjectOutputStream;  
    import java.math.BigInteger;  
    import java.security.KeyFactory;  
    import java.security.KeyPair;  
    import java.security.KeyPairGenerator;  
    import java.security.NoSuchAlgorithmException;  
    import java.security.PrivateKey;  
    import java.security.PublicKey;  
    import java.security.SecureRandom;  
    import java.security.interfaces.RSAPrivateKey;  
    import java.security.interfaces.RSAPublicKey;  
    import java.security.spec.InvalidKeySpecException;  
    import java.security.spec.RSAPrivateKeySpec;  
    import java.security.spec.RSAPublicKeySpec;  
      
    import javax.crypto.Cipher;  
      
    /** 
     * RSA    。    ,  ,        。 
     *    http://www.bouncycastle.org  bcprov-jdk14-123.jar。 
     *  
     */  
    public class RSAUtil {  
          
        private static String RSAKeyStore = "C:/RSAKey.txt";  
        /** 
         * *       * 
         *  
         * @return KeyPair * 
         * @throws EncryptException 
         */  
        public static KeyPair generateKeyPair() throws Exception {  
            try {  
                KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA",  
                        new org.bouncycastle.jce.provider.BouncyCastleProvider());  
                final int KEY_SIZE = 1024;//        ,            ,    ,      ,        
                keyPairGen.initialize(KEY_SIZE, new SecureRandom());  
                KeyPair keyPair = keyPairGen.generateKeyPair();  
                  
                System.out.println(keyPair.getPrivate());  
                System.out.println(keyPair.getPublic());  
                  
                saveKeyPair(keyPair);  
                return keyPair;  
            } catch (Exception e) {  
                throw new Exception(e.getMessage());  
            }  
        }  
      
        public static KeyPair getKeyPair() throws Exception {  
            FileInputStream fis = new FileInputStream(RSAKeyStore);  
            ObjectInputStream oos = new ObjectInputStream(fis);  
            KeyPair kp = (KeyPair) oos.readObject();  
            oos.close();  
            fis.close();  
            return kp;  
        }  
      
        public static void saveKeyPair(KeyPair kp) throws Exception {  
      
            FileOutputStream fos = new FileOutputStream(RSAKeyStore);  
            ObjectOutputStream oos = new ObjectOutputStream(fos);  
            //       
            oos.writeObject(kp);  
            oos.close();  
            fos.close();  
        }  
      
        /** 
         * *      * 
         *  
         * @param modulus * 
         * @param publicExponent * 
         * @return RSAPublicKey * 
         * @throws Exception 
         */  
        public static RSAPublicKey generateRSAPublicKey(byte[] modulus,  
                byte[] publicExponent) throws Exception {  
            KeyFactory keyFac = null;  
            try {  
                keyFac = KeyFactory.getInstance("RSA",  
                        new org.bouncycastle.jce.provider.BouncyCastleProvider());  
            } catch (NoSuchAlgorithmException ex) {  
                throw new Exception(ex.getMessage());  
            }  
      
            RSAPublicKeySpec pubKeySpec = new RSAPublicKeySpec(new BigInteger(  
                    modulus), new BigInteger(publicExponent));  
            try {  
                return (RSAPublicKey) keyFac.generatePublic(pubKeySpec);  
            } catch (InvalidKeySpecException ex) {  
                throw new Exception(ex.getMessage());  
            }  
        }  
      
        /** 
         * *      * 
         *  
         * @param modulus * 
         * @param privateExponent * 
         * @return RSAPrivateKey * 
         * @throws Exception 
         */  
        public static RSAPrivateKey generateRSAPrivateKey(byte[] modulus,  
                byte[] privateExponent) throws Exception {  
            KeyFactory keyFac = null;  
            try {  
                keyFac = KeyFactory.getInstance("RSA",  
                        new org.bouncycastle.jce.provider.BouncyCastleProvider());  
            } catch (NoSuchAlgorithmException ex) {  
                throw new Exception(ex.getMessage());  
            }  
      
            RSAPrivateKeySpec priKeySpec = new RSAPrivateKeySpec(new BigInteger(  
                    modulus), new BigInteger(privateExponent));  
            try {  
                return (RSAPrivateKey) keyFac.generatePrivate(priKeySpec);  
            } catch (InvalidKeySpecException ex) {  
                throw new Exception(ex.getMessage());  
            }  
        }  
      
        /** 
         * *    * 
         *  
         * @param key 
         *                  * 
         * @param data 
         *                     * 
         * @return        * 
         * @throws Exception 
         */  
        public static byte[] encrypt(PublicKey pk, byte[] data) throws Exception {  
            try {  
                Cipher cipher = Cipher.getInstance("RSA",  
                        new org.bouncycastle.jce.provider.BouncyCastleProvider());  
                cipher.init(Cipher.ENCRYPT_MODE, pk);  
                int blockSize = cipher.getBlockSize();//        , :      128 byte, key_size=1024  
                //       127  
                // byte,    128 byte;    2    ,   127  
                // byte    1 byte  
                int outputSize = cipher.getOutputSize(data.length);//              
                int leavedSize = data.length % blockSize;  
                int blocksSize = leavedSize != 0 ? data.length / blockSize + 1  
                        : data.length / blockSize;  
                byte[] raw = new byte[outputSize * blocksSize];  
                int i = 0;  
                while (data.length - i * blockSize > 0) {  
                    if (data.length - i * blockSize > blockSize)  
                        cipher.doFinal(data, i * blockSize, blockSize, raw, i  
                                * outputSize);  
                    else  
                        cipher.doFinal(data, i * blockSize, data.length - i  
                                * blockSize, raw, i * outputSize);  
                    //    doUpdate     ,          doUpdate             byte[]    
                    // ByteArrayOutputStream ,   doFinal        byte[]    ,                     
                    // OutputSize     dofinal  。  
      
                    i++;  
                }  
                return raw;  
            } catch (Exception e) {  
                throw new Exception(e.getMessage());  
            }  
        }  
      
        /** 
         * *    * 
         *  
         * @param key 
         *                  * 
         * @param raw 
         *                    * 
         * @return        * 
         * @throws Exception 
         */  
        public static byte[] decrypt(PrivateKey pk, byte[] raw) throws Exception {  
            try {  
                Cipher cipher = Cipher.getInstance("RSA",  
                        new org.bouncycastle.jce.provider.BouncyCastleProvider());  
                cipher.init(cipher.DECRYPT_MODE, pk);  
                int blockSize = cipher.getBlockSize();  
                ByteArrayOutputStream bout = new ByteArrayOutputStream(64);  
                int j = 0;  
      
                while (raw.length - j * blockSize > 0) {  
                    bout.write(cipher.doFinal(raw, j * blockSize, blockSize));  
                    j++;  
                }  
                return bout.toByteArray();  
            } catch (Exception e) {  
                throw new Exception(e.getMessage());  
            }  
        }  
      
        /** 
         * * * 
         *  
         * @param args * 
         * @throws Exception 
         */  
        public static void main(String[] args) throws Exception {  
            RSAPublicKey rsap = (RSAPublicKey) RSAUtil.generateKeyPair().getPublic();  
            String test = "hello world";  
            byte[] en_test = encrypt(getKeyPair().getPublic(), test.getBytes());  
            byte[] de_test = decrypt(getKeyPair().getPrivate(), en_test);  
            System.out.println(new String(de_test));  
        }  
    }  

 
LoginAction.java
    package RSA;  
      
    //login  
    /* 
     * Generated by MyEclipse Struts 
     * Template path: templates/java/JavaClass.vtl 
     */  
    import java.math.BigInteger;  
    import java.net.URLDecoder;  
    import java.net.URLEncoder;  
      
    import javax.servlet.http.HttpServletRequest;  
    import javax.servlet.http.HttpServletResponse;  
      
    import RSA.RSAUtil;  
      
    /** 
     * MyEclipse Struts Creation date: 06-28-2008 
     *  
     * XDoclet definition: 
     *  
     * @struts.action path="/login" name="loginForm" input="/login.jsp" 
     *                scope="request" validate="true" 
     * @struts.action-forward name="error" path="/error.jsp" 
     * @struts.action-forward name="success" path="/success.jsp" 
     */  
    public class LoginAction {  
        /* 
         * Generated Methods 
         */  
      
        /** 
         * Method execute 
         *  
         * @param mapping 
         * @param form 
         * @param request 
         * @param response 
         * @return ActionForward 
         */  
        public boolean execute(HttpServletRequest request,  
                HttpServletResponse response) throws Exception {  
            String pwd ;  
            String result = request.getParameter("result");  
            System.out.println("      :");  
            System.out.println(result);  
            byte[] en_result = new BigInteger(result, 16).toByteArray();  
            //System.out.println("  byte[]" + new String(en_result));  
            byte[] de_result = RSAUtil.decrypt(RSAUtil.getKeyPair().getPrivate(),  
                    en_result);  
            System.out.println("    :");  
            System.out.println(new String(de_result));  
            StringBuffer sb = new StringBuffer();  
            sb.append(new String(de_result));  
            pwd = sb.reverse().toString();  
            System.out.println(sb);  
            System.out.println("=================================");  
            pwd = URLDecoder.decode(pwd,"UTF-8");//  
            System.out.println(pwd);  
            request.setAttribute("pwd", pwd);  
            return true;  
        }  
    }  

 
ログインlogin.jsp
    <%@ page language="java" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>  
      
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">  
    <html:html lang="true">  
    <head>  
        <title>login</title>  
      
        <script type="text/javascript" src="js/RSA.js"></script>  
        <script type="text/javascript" src="js/BigInt.js"></script>  
        <script type="text/javascript" src="js/Barrett.js"></script>  
          
        <script type="text/javascript">  
    function rsalogin(){  
        var thisPwd = document.getElementById("password").value;  
        bodyRSA();  
        var result = encryptedString(key, encodeURIComponent(thisPwd));  
        //alert(encodeURIComponent(thisPwd)+"\r
"+result); loginForm.action="loginCHK.jsp?result="+result; loginForm.submit(); } var key ; function bodyRSA(){ setMaxDigits(130); key = new RSAKeyPair("10001","","8246a46f44fc4d961e139fd70f4787d272d374532f4d2d9b7cbaad6a15a8c1301319aa6b3f30413b859351c71938aec516fa7147b69168b195e81df46b6bed7950cf3a1c719d42175f73d7c97a85d7d20a9e83688b92f05b3059bb2ff75cd7190a042cd2db97ebc2ab4da366f2a7085556ed613b5a39c9fdd2bb2595d1dc23b5"); } </script> </head> <body> <form method="post" name="loginForm" target=_blank> <table border="0"> <tr> <td> Password: </td> <td> <input type='text' name="password" id=password style='width:400px' value="my passwd"/> </td> </tr> <tr> <td colspan="2" align="center"> <input type="button" value="SUBMIT" onclick="rsalogin();" /> </td> </tr> </table> </form> </body> </html:html>

 
ログインチェックloginCHK.jsp
    <%@ page language="java" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>  
      
    <jsp:directive.page import="RSA.LoginAction"/>  
      
    <%  
    LoginAction la = new LoginAction();  
    la.execute(request ,response);  
    %>  
    pwd is [<%=request.getAttribute("pwd")%>]  

 
また、RSAにより、秘密鍵で署名し、公開鍵で検証すればよいデジタル署名も実現できる.具体的には、コードを参照してください.
    package encode;  
      
    import java.security.KeyPair;  
    import java.security.KeyPairGenerator;  
    import java.security.Signature;  
      
    public class DigitalSignature2Example {  
        public static void main(String[] args) {  
            args = new String[] { "  " };  
              
            if (args.length != 1) {  
                System.err.println("Usage:java DigitalSignature2Example ");  
                System.exit(1);  
            }  
      
            try {  
                byte[] plainText = args[0].getBytes("UTF-8");  
                System.out.println("
Start generating RSA key."); // RSA KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA"); // keyGen.initialize(1024); // KeyPair pair = keyGen.generateKeyPair(); System.out.println("
Finish generating RSA key."); // Signature sig = Signature.getInstance("SHA1WithRSA"); // sig.initSign(pair.getPrivate()); // sig.update(plainText); // byte[] signature = sig.sign(); System.out.println(sig.getProvider().getInfo()); System.out.println("
Signature: "); System.out.println(new String(signature, "UTF-8")); // System.out.println("
Start signature verification."); sig.initVerify(pair.getPublic()); // sig.update(plainText); if (sig.verify(signature)) { System.out.println("Signature verificated."); } else { System.out.println("Signature failed."); } } catch (Exception e) { e.printStackTrace(); } } }