SSL/TLS協議運行機制

http://blog.csdn.net/fw0124/article/details/41013333

 

關於SSL/TLS/JSSE的介紹：
1）SSL/TLS協議運行機制
2）圖解SSL/TLS協議
3）使用wireshark觀察SSL/TLS握手過程
4）SSL/TLS的Java實現--JSSE

（一）使用keytool建立密鑰庫

使用雙向認證的SSL/TLS協議通訊，客戶端和服務器端都要設置用於證明本身身份的安全證書，而且還要設置信任對方的哪些安全證書。
理論上一共須要準備四個文件，兩個keystore文件和兩個truststore文件。
通訊雙方分別擁有一個keystore和一個truststore，keystore用於存放本身的密鑰和公鑰，truststore用於存放全部須要信任方的公鑰。

首先使用JDK自帶的keytool工具來生成keystore和truststore。這裏使用的Java版本是1.7。
1）建立server的keystore文件，生成server的公鑰/私鑰密鑰對。須要指定keystore的密碼(storepass)和密鑰對的密碼(keypass)。
訪問keystore須要storepass。訪問密鑰對須要keypass。

<span style="font-family:Verdana;">C:\Program Files\Java\jre7\bin>keytool -genkey -alias catserver -keyalg rsa -keysize 1024 -sigalg sha256withrsa -keypass catserver -keystore c:\_tmp\catserver.keystore -storepass catserverks
What is your first and last name?
[Unknown]: cat
What is the name of your organizational unit?
[Unknown]: cat
What is the name of your organization?
[Unknown]: cat
What is the name of your City or Locality?
[Unknown]: cat
What is the name of your State or Province?
[Unknown]: cat
What is the two-letter country code for this unit?
[Unknown]: ct
Is CN=cat, OU=cat, O=cat, L=cat, ST=cat, C=ct correct?
[no]: y</span>

2）建立client的keystore文件。一樣須要指定keystore的密碼和密鑰對的密碼。

<span style="font-family:Verdana;">C:\Program Files\Java\jre7\bin>keytool -genkey -alias foxclient -keyalg dsa -keysize 512 -sigalg sha1withdsa -keypass foxclient -keystore c:\_tmp\foxclient.keystore -storepass foxclientks
What is your first and last name?
[Unknown]: fox
What is the name of your organizational unit?
[Unknown]: fox
What is the name of your organization?
[Unknown]: fox
What is the name of your City or Locality?
[Unknown]: fox
What is the name of your State or Province?
[Unknown]: fox
What is the two-letter country code for this unit?
[Unknown]: fx
Is CN=fox, OU=fox, O=fox, L=fox, ST=fox, C=fx correct?
[no]: y</span>

3）從server的keystore中導出server的證書（其中包括server的公鑰）。

<span style="font-family:Verdana;">C:\Program Files\Java\jre7\bin>keytool -export -alias catserver -keystore c:\_tmp\catserver.keystore -storepass catserverks -file c:\_tmp\catserver.cer
Certificate stored in file <c:\_tmp\catserver.cer>
</span>

4）從client的keystore中導出client的證書（其中包括client的公鑰）。

<span style="font-family:Verdana;">C:\Program Files\Java\jre7\bin>keytool -export -alias foxclient -keystore c:\_tmp\foxclient.keystore -storepass foxclientks -file c:\_tmp\foxclient.cer
Certificate stored in file <c:\_tmp\foxclient.cer>
</span>

5）建立server的truststore文件並導入client的證書（其中包括client的公鑰）。

<span style="font-family:Verdana;">C:\Program Files\Java\jre7\bin>keytool -import -alias foxclient -keystore c:\_tmp\catservertrust.keystore -storepass catservertrustks -file c:\_tmp\foxclient.cer
Owner: CN=fox, OU=fox, O=fox, L=fox, ST=fox, C=fx
Issuer: CN=fox, OU=fox, O=fox, L=fox, ST=fox, C=fx
Serial number: 6eaf996f
Valid from: Wed Nov 05 16:15:41 CST 2014 until: Tue Feb 03 16:15:41 CST 2015
Certificate fingerprints:
MD5: B5:B6:92:66:84:92:A0:C2:F5:40:39:25:F8:66:2A:17
SHA1: 07:42:A3:1A:49:7B:C9:34:4B:6B:FA:37:6C:20:98:D4:20:13:7C:91
SHA256: 37:A5:00:A3:13:00:DE:99:3B:08:47:F6:1E:8A:05:F1:4A:B2:C6:22:20:
E1:AF:0E:05:B2:CE:E0:2F:94:B6:94
Signature algorithm name: SHA1withDSA
Version: 3

Extensions:

#1: ObjectId: 2.5.29.14 Criticality=false
SubjectKeyIdentifier [
KeyIdentifier [
0000: 69 3E 6A D0 B5 B1 1F BD 48 46 E1 A4 6C 1F 71 90 i>j.....HF..l.q.
0010: 29 06 3B 32 ).;2
]
]

Trust this certificate? [no]: y
Certificate was added to keystore</span>

6）建立client的truststore文件並導入server的證書（其中包括server的公鑰）。

<span style="font-family:Verdana;">C:\Program Files\Java\jre7\bin>keytool -import -alias catserver -keystore c:\_tmp\foxclienttrust.keystore -storepass foxclienttrustks -file c:\_tmp\catserver.cer
Owner: CN=cat, OU=cat, O=cat, L=cat, ST=cat, C=ct
Issuer: CN=cat, OU=cat, O=cat, L=cat, ST=cat, C=ct
Serial number: 3e421457
Valid from: Wed Nov 05 16:13:52 CST 2014 until: Tue Feb 03 16:13:52 CST 2015
Certificate fingerprints:
MD5: 20:44:7C:E5:30:E6:7A:21:C2:49:64:77:E1:3A:A0:77
SHA1: 8B:02:D2:BE:98:2F:99:94:08:47:E2:96:EC:05:1B:5D:B1:8F:30:2F
SHA256: A6:66:85:F4:C2:B2:06:4E:2E:40:D8:52:84:6E:85:2B:5B:BB:C3:B0:9C:
31:92:99:F5:91:5D:83:67:C8:4D:D8
Signature algorithm name: SHA256withRSA
Version: 3

Extensions:

#1: ObjectId: 2.5.29.14 Criticality=false
SubjectKeyIdentifier [
KeyIdentifier [
0000: F5 91 E6 14 EE EF 5F 24 4F AC 6F A6 B8 36 A6 11 ......_$O.o..6..
0010: 2B 5C DF 04 +\..
]
]

Trust this certificate? [no]: y
Certificate was added to keystore</span>

keysize
若是加密算法是rsa，key size範圍512->16384 bits，而且必須是64的倍數。
若是加密算法是dsa，key size範圍512->1024 bits，而且必須是64的倍數。

sigalg
若是加密算法是rsa，簽名算法能夠是md5withrsa/sha1withrsa/sha256withrsa/sha384withrsa/sha512withrsa
若是加密算法是dsa，簽名算法能夠是sha1withdsa

若是熟悉Java的socket編程，就會發現使用JSSE進行SSL/TLS編程其實和它很類似。
區別在於ServerSocket對象換成了SSLServerSocket，Socket對象換成了SSLSocket對象。

（二）server端處理流程和代碼

處理流程：
1）加載server的keystore文件，須要指定keystore的密碼(storepass)。
KeyStore類型有以下三種： 
jceks - The proprietary keystore implementation provided by the SunJCE provider. 
jks - The proprietary keystore implementation provided by the SUN provider. 
pkcs12 - The transfer syntax for personal identity information as defined in PKCS #12.

2）加載server的truststore文件，須要指定truststore的密碼(storepass)。

3) 建立KeyManagerFactory對象並用1）中加載的keystore和server密鑰對的密碼(keypass)來初始化。

4) 建立TrustManagerFactory對象並用2）中加載的truststore來初始化。truststore中存的是client的公鑰，不須要keypass也能夠訪問。

5）建立SSLContext並用3）和4）中建立的KeyManagerFactory和TrustManagerFactory對象來初始化。
http://docs.Oracle.com/javase/7/docs/technotes/guides/security/StandardNames.html#SSLContext
建立SSLContext是須要給出SSLContext Algorithms。上面這個連接中給出了合法的SSLContext Algorithms，有以下可用值。
SSL - Supports some version of SSL; may support other versions 
SSLv2 - Supports SSL version 2 or later; may support other versions 
SSLv3 - Supports SSL version 3; may support other versions 
TLS - Supports some version of TLS; may support other versions 
TLSv1 - Supports RFC 2246: TLS version 1.0 ; may support other versions 
TLSv1.1 - Supports RFC 4346: TLS version 1.1 ; may support other versions 
TLSv1.2 - Supports RFC 5246: TLS version 1.2 ; may support other versions 

6）建立SSLServerSocketFactory，在指定的端口上建立SSLServerSocket並設定須要客戶端證書：setNeedClientAuth(true)

7）在SSLServerSocket對象上調用accept()方法等待客戶端的鏈接。
客戶端連上來以後這個函數會返回一個SSLSocket對象，在這個對象的輸入輸出流上進行讀寫。
在這個SSLSocket對象上能夠添加一個HandshakeCompletedListener的監聽器，SSL/TLS握手結束後這個監聽器的handshakeCompleted方法就會被調用。
客戶端有三種方法會觸發握手：
- 顯式調用startHandshake方法/calling startHandshake which explicitly begins handshakes, or
- 在socket對象上進行read或write操做/any attempt to read or write application data on this socket causes an implicit handshake, or
- 在socket對象上調用getSession方法/a call to getSession tries to set up a session if there is no currently valid session, and an implicit handshake is done.

<span style="font-family:Verdana;">package learning.net.ssl;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.security.KeyStore;
import java.security.cert.X509Certificate;

import javax.net.ssl.HandshakeCompletedEvent;
import javax.net.ssl.HandshakeCompletedListener;
import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLPeerUnverifiedException;
import javax.net.ssl.SSLServerSocket;
import javax.net.ssl.SSLServerSocketFactory;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.TrustManagerFactory;

public class CatServer implements Runnable, HandshakeCompletedListener {

    public static final int SERVER_PORT = 11123;

    private final Socket _s;
    private String peerCerName;

    public CatServer(Socket s) {
        _s = s;
    }

    public static void main(String[] args) throws Exception {
        String serverKeyStoreFile = "c:\\_tmp\\catserver.keystore";
        String serverKeyStorePwd = "catserverks";
        String catServerKeyPwd = "catserver";
        String serverTrustKeyStoreFile = "c:\\_tmp\\catservertrust.keystore";
        String serverTrustKeyStorePwd = "catservertrustks";

        KeyStore serverKeyStore = KeyStore.getInstance("JKS");
        serverKeyStore.load(new FileInputStream(serverKeyStoreFile), serverKeyStorePwd.toCharArray());

        KeyStore serverTrustKeyStore = KeyStore.getInstance("JKS");
        serverTrustKeyStore.load(new FileInputStream(serverTrustKeyStoreFile), serverTrustKeyStorePwd.toCharArray());

        KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
        kmf.init(serverKeyStore, catServerKeyPwd.toCharArray());

        TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        tmf.init(serverTrustKeyStore);

        SSLContext sslContext = SSLContext.getInstance("TLSv1");
        sslContext.init(kmf.getKeyManagers(), tmf.getTrustManagers(), null);

        SSLServerSocketFactory sslServerSocketFactory = sslContext.getServerSocketFactory();
        SSLServerSocket sslServerSocket = (SSLServerSocket) sslServerSocketFactory.createServerSocket(SERVER_PORT);
        sslServerSocket.setNeedClientAuth(true);

        while (true) {
            SSLSocket s = (SSLSocket)sslServerSocket.accept();
            CatServer cs = new CatServer(s);
            s.addHandshakeCompletedListener(cs);
            new Thread(cs).start();
        }
    }

    @Override
    public void run() {
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(_s.getInputStream()));
            PrintWriter writer = new PrintWriter(_s.getOutputStream(), true);

            writer.println("Welcome~, enter exit to leave.");
            String s;
            while ((s = reader.readLine()) != null && !s.trim().equalsIgnoreCase("exit")) {
                writer.println("Echo: " + s);
            }
            writer.println("Bye~, " + peerCerName);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                _s.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    public void handshakeCompleted(HandshakeCompletedEvent event) {
        try {
            X509Certificate cert = (X509Certificate) event.getPeerCertificates()[0];
            peerCerName = cert.getSubjectX500Principal().getName();
        } catch (SSLPeerUnverifiedException ex) {
            ex.printStackTrace();
        }
    }

}</span>

（三）client端處理流程和代碼

處理流程：（1~5和server相同）
1）加載client的keystore文件。

2）加載client的truststore文件。

3) 建立KeyManagerFactory對象並初始化。

4) 建立TrustManagerFactory對象並初始化。truststore中存的是server的公鑰，不須要keypass也能夠訪問。

5）建立SSLContext並用3）和4）中建立的KeyManagerFactory和TrustManagerFactory對象來初始化。

6）建立SSLSocketFactory，在指定的網絡地址和端口上建立SSLSocket。

7）在這個SSLSocket對象的輸入輸出流上進行讀寫。

<span style="font-family:Verdana;">package learning.net.ssl;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.security.KeyStore;

import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManagerFactory;

public class FoxClient {
    public static void main(String[] args) throws Exception {
        String clientKeyStoreFile = "c:\\_tmp\\foxclient.keystore";
        String clientKeyStorePwd = "foxclientks";
        String foxclientKeyPwd = "foxclient";
        String clientTrustKeyStoreFile = "c:\\_tmp\\foxclienttrust.keystore";
        String clientTrustKeyStorePwd = "foxclienttrustks";

        KeyStore clientKeyStore = KeyStore.getInstance("JKS");
        clientKeyStore.load(new FileInputStream(clientKeyStoreFile), clientKeyStorePwd.toCharArray());

        KeyStore clientTrustKeyStore = KeyStore.getInstance("JKS");
        clientTrustKeyStore.load(new FileInputStream(clientTrustKeyStoreFile), clientTrustKeyStorePwd.toCharArray());

        KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
        kmf.init(clientKeyStore, foxclientKeyPwd.toCharArray());

        TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        tmf.init(clientTrustKeyStore);

        SSLContext sslContext = SSLContext.getInstance("TLSv1");
        sslContext.init(kmf.getKeyManagers(), tmf.getTrustManagers(), null);

        SSLSocketFactory socketFactory = sslContext.getSocketFactory();
        Socket socket = socketFactory.createSocket("localhost", CatServer.SERVER_PORT);

        PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

        send("hello", out);
        send("exit", out);
        receive(in);
        socket.close();
    }

    public static void send(String s, PrintWriter out) throws IOException {
        System.out.println("Sending: " + s);
        out.println(s);
    }

    public static void receive(BufferedReader in) throws IOException {
        String s;
        while ((s = in.readLine()) != null) {
            System.out.println("Reveived: " + s);
        }
    }
}</span>

 

 

（四）使用Openssl進行證書籤名

若是須要對證書進行簽名，可使用keytool生成一個csr(certificate sign request), 而後提交到一個CA進行簽名。這裏使用openssl提供的CA功能。

 

1）[openssl]生成CA的RSA私鑰。
bash-3.00$ openssl genrsa -out cakey.pem 1024

2）[openssl]使用CA.sh腳本初始化CA。腳本會要求輸入剛纔生成的私鑰文件。
bash-3.00$ CA.sh -newca
CA certificate filename (or enter to create)
cakey.pem

3）[openssl]利用CA私鑰生成自簽名的CA根證書。
指定x509參數表示要生成自簽名的證書。（咱們知道證書裏面只包含公鑰，爲何從私鑰能夠生成證書呢？這是由於私鑰裏面包含RSA算法所需的參數，其實能夠算出公鑰，後面會詳細解釋）
bash-3.00$ openssl req -new -x509 -key cakey.pem -out ca.cer -config openssl.cnf
（Linux上openssl.cnf的路徑/etc/pki/tls/openssl.cnf，能夠拷貝一份到當前目錄）

4）[keytool]生成server的keystore文件。
C:\Program Files\Java\jre7>keytool -genkey -alias catserver -keyalg rsa -keysize 1024 -sigalg sha256withrsa -keypass catserver -keystore c:\_tmp\catserver.keystore -storepass catserverks

5）[keytool]生成server的csr.
C:\Program Files\Java\jre7>keytool -certreq -alias catserver -file c:\_tmp\catserver.csr -keypass catserver -keystore c:\_tmp\catserver.keystore -storepass catserverks

6) [openssl]對server的csr進行簽名獲得server證書
bash-3.00$ openssl ca -in catserver.csr -out catserver.cer -cert ca.cer -keyfile cakey.pem -config openssl.cnf
（若是是由於權限問題，不能訪問CA的newcerts目錄，能夠先進行以下操做：
bash-3.00$ mkdir newcerts 
bash-3.00$ touch index.txt 
bash-3.00$ echo 01 > serial）

7）[keytool]生成client的keystore文件。
C:\Program Files\Java\jre7>keytool -genkey -alias foxclient -keyalg dsa -keysize 512 -sigalg sha1withdsa -keypass foxclient -keystore c:\_tmp\foxclient.keystore -storepass foxclientks

8）[keytool]生成client的csr.
C:\Program Files\Java\jre7>keytool -certreq -alias foxclient -file c:\_tmp\foxclient.csr -keypass foxclient -keystore c:\_tmp\foxclient.keystore -storepass foxclientks

9) [openssl]對client的csr進行簽名獲得client證書
bash-3.00$ openssl ca -in foxclient.csr -out foxclient.cer -cert ca.cer -keyfile cakey.pem -config openssl.cnf

如今咱們有以下文件:
catserver.keystore -- server的keystore文件
catserver.cer -- server證書文件，已經由CA簽名。

foxclient.keystore -- client的keystore文件
foxclient.cer -- client證書文件，已經由CA簽名。

ca.cer -- CA的證書文件。做爲根證書。

接下來咱們還須要
10）[keytool]導入ca.cer和catserver.cer到catserver.keystore
keytool -import -trustcacerts -alias ca -keystore c:\_tmp\catserver.keystore -storepass catserverks -file c:\_tmp\ca.cer
keytool -import -alias catserver -keypass catserver -keystore c:\_tmp\catserver.keystore -storepass catserverks -file c:\_tmp\catserver.cer

11）[keytool]導入ca.cer和foxclient.cer到foxclient.keystore
keytool -import -trustcacerts -alias ca -keystore c:\_tmp\foxclient.keystore -storepass foxclientks -file c:\_tmp\ca.cer
keytool -import -alias foxclient -keypass foxclient -keystore c:\_tmp\foxclient.keystore -storepass foxclientks -file c:\_tmp\foxclient.cer

12）[keytool]建立server的truststore文件並導入ca.cer和foxclient.cer.
keytool -import -trustcacerts -alias ca -keystore c:\_tmp\catservertrust.keystore -storepass catservertrustks -file c:\_tmp\ca.cer
keytool -import -alias foxclient -keystore c:\_tmp\catservertrust.keystore -storepass catservertrustks -file c:\_tmp\foxclient.cer

13）[keytool]建立client的truststore文件並導入ca.cer和catserver.cer.
keytool -import -trustcacerts -alias ca -keystore c:\_tmp\foxclienttrust.keystore -storepass foxclienttrustks -file c:\_tmp\ca.cer
keytool -import -alias catserver -keystore c:\_tmp\foxclienttrust.keystore -storepass foxclienttrustks -file c:\_tmp\catserver.cer

 

*前面提到能夠從CA的私鑰文件生成CA的根證書。證書裏面其實包含的是公鑰。
其實openssl也提供命令能夠直接從私鑰cakey.pem生成公鑰。
openssl rsa -in cakey.pem -pubout -out caputkey.pem
爲何可以從私鑰推導出公鑰呢？
這須要瞭解RSA算法-〉http://blog.csdn.NET/fw0124/article/details/41118525
緣由很簡單，由於私鑰中也包含了計算公鑰所需的參數n和e。

*可使用openssl來生成server的證書，步驟以下
openssl genrsa -out catserverkey.pem 1024
openssl req -new -key catserverkey.pem -out catserver.csr -config openssl.cnf
openssl ca -in catserver.csr -out catserver.cer -cert ca.cer -keyfile cakey.pem -config openssl.cnf

=====================================

若是openssl ca ...進行簽名的時候碰到
The stateOrProvinceName field needed to be the same in the ...的錯誤，能夠修改openssl.cnf文件：
[ policy_match ]
countryName             = optional
stateOrProvinceName     = optional
organizationName        = optional
organizationalUnitName  = optional

若是遇到
failed to update database
TXT_DB error number 2     的錯誤，
刪除index.txt,並再touch下

 

若是keytool -import命令導入簽名後的證書的時候遇到如下錯誤
keytool 錯誤: java.lang.Exception: 沒法從回覆中創建鏈
從新導入下ca.cer便可。
keytool -delete -alias ca -keystore c:\_tmp\catserver.keystore -storepass catserverks
keytool -import -trustcacerts -alias ca ...

======================================

 

CER文件到PEM文件的轉換較簡單。這二者都是X509證書，編碼不一樣，使用openssl工具便可：

openssl x509 -inform der -in catserver.cer -out catserver.pem

 

 

（五）如何從.keystore文件中導出私鑰

Keytool不支持直接從.keystore中導出私鑰。可是能夠把JKS文件轉換成openssl支持的PKCS＃12格式的文件。

 

因此能夠經過下面2步來從.keystore中導出私鑰。

➜ ~ keytool -importkeystore -srckeystore catserver.keystore -destkeystore catserver.p12 -deststoretype PKCS12 -srcalias catserver -srcstorepass catserverks -srckeypass catserver -deststorepass catserverks -destkeypass catserver
Warning: Different store and key passwords not supported for PKCS12 KeyStores. Ignoring user-specified -destkeypass value.
➜  ~  openssl pkcs12 -in catserver.p12  -nodes -nocerts -out catserverkey.pem
Enter Import Password:
MAC verified OK
➜  ~

＊-nodes選項意思是No DES，即不加密導出的私鑰。