随着大家安全意识的提高，越来越多的软件采用https代替http进行网络传输信息，与http的明文传输不同，https在网络传输的应用层与传输层增加了一个中间层（SSL或TLS），用来对传输的明文数据进行加密处理，从而保证了网络传输的隐私性和安全性。
前段时间因为项目原因，需要android手机客户端和服务器端进行通信，在学习过程中遇到了一些坑，特记录以供后面备忘。
因为有传输文件的需求，所以我在使用时采用的是appache的HttpClient，而不是HttpURLConnection, 因为appache的包中的MultipartEntity类封装了上传时的multipart/form-data格式，同时还支持多个文件同时上传，减少了重复造轮子的可能性。
先看一下HttpClient给的https连接的demo:
public final static void main(String[] args) throws Exception {
DefaultHttpClient httpclient = new DefaultHttpClient();
try {
KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
FileInputStream instream = new FileInputStream(new File("my.keystore"));
try {
trustStore.load(instream, "nopassword".toCharArray());
} finally {
try { instream.close(); } catch (Exception ignore) {}
}
SSLSocketFactory socketFactory = new SSLSocketFactory(trustStore);
Scheme sch = new Scheme("https", 443, socketFactory);
httpclient.getConnectionManager().getSchemeRegistry().register(sch);
HttpGet httpget = new HttpGet("https://localhost/");
System.out.println("executing request" + httpget.getRequestLine());
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
System.out.println("----------------------------------------");
System.out.println(response.getStatusLine());
if (entity != null) {
System.out.println("Response content length: " + entity.getContentLength());
}
EntityUtils.consume(entity);
} finally {
// When HttpClient instance is no longer needed,
// shut down the connection manager to ensure
// immediate deallocation of all system resources
httpclient.getConnectionManager().shutdown();
}
}如果你是的证书使用java自带的keygen生成的话，上面的例子基本已经可以开箱即用了。
由于我的服务器是用golang写的，害怕服务器端不认识keygen生成的证书，所以采用了openssl来生成证书。
生成自签名证书：
生成私钥，采用DES3加密，https握手采用RSA 2048
$openssl genrsa des3 out server.key 2048
Generating RSA private key, 2048 bit long modulus
.........................................................++++++
........++++++
e is 65537 (0x10001)
Enter PEM pass phrase:
Verifying password Enter PEM pass phrase:生成证书签名请求，注意common name填写你的host ip或者域名：
$openssl req new key server.key out server.csr
Country Name (2 letter code) [GB]: CN
State or Province Name (full name) [Berkshire]: ShangHai
Locality Name (eg, city) [Newbury]: shanghai
Organization Name (eg, company) [My Company Ltd]:
Organizational Unit Name (eg, section) []:
Common Name (eg, your name or your server's hostname) []: baidu.com
Email Address []: martin dot zahn at akadia dot ch
Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:如果嫌加密私钥太麻烦，可以去掉：
$cp server.key server.key.org
$openssl rsa in server.key.org out server.key
$ll
rwrr 1 root root 745 Jun 29 12:19 server.csr
rwrr 1 root root 891 Jun 29 13:22 server.key
rwrr 1 root root 963 Jun 29 13:22 server.key.org自签名我们的证书,有效期一年：
openssl x509 req days 365 in server.csr signkey server.key out server.crt这样生成的证书是采用PKCS12打包的，而java的TrustStore似乎对该格式支持的并不好，直接load，结果发现：
Exception in thread "main" java.lang.AssertionError: java.io.IOException: toDerInputStream rejects tag type 45
Exception in thread "main" java.lang.AssertionError: java.security.KeyStoreException: TrustedCertEntry not supported
然后Google了一下，好像有一个开源的加解密项目支持的还不错http://www.bouncycastle.org/，果断下载试试：http://www.bouncycastle.org/download/bcprov-ext-jdk15on-153.jar，话说这下载速度也是够慢的。
然后添加该套件供应商：
Security.addProvider(new BouncyCastleProvider());
KeyStore trusted = KeyStore.getInstance("PKCS12", "BC");再次运行，结果又悲催了：
Exception in thread "main" java.lang.AssertionError: java.lang.NullPointerException: No password supplied for PKCS#12 KeyStore.
好吧，既然这样，那我初始话一个空的keystore，然后曲线救国总可以吧：
Security.addProvider(new BouncyCastleProvider());
KeyStore trusted = KeyStore.getInstance("PKCS12", "BC");
// Get the raw resource, which contains the keystore with
// your trusted certificates (root and any intermediate certs)
InputStream in = getClass().getResourceAsStream("/server.crt");
// Initialize the keystore with the provided trusted certificates
// Also provide the password of the keystore
// trusted.load(in, "mysecret".toCharArray());
trusted.load(null, null);
CertificateFactory certificateFactory = CertificateFactory
.getInstance("X.509");
Certificate certificate = certificateFactory
.generateCertificate(in);
trusted.setCertificateEntry("trust", certificate);
in.close();ok,问题解决，总算能愉（苦）快（逼）的继续玩耍了～_～, 顺便附上我的HttpsClient：
package com.snail.myapp.http;
import com.snail.myapp.App;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.scheme.PlainSocketFactory;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.SingleClientConnManager;
import java.io.InputStream;
import java.security.KeyStore;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
/**
* Created by daemonw on 15-10-10.
*/
public class HttpsClient extends DefaultHttpClient{
protected ClientConnectionManager createClientConnectionManager() {
SchemeRegistry registry = new SchemeRegistry();
registry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
// Register for port 443 our SSLSocketFactory with our keystore
// to the ConnectionManager
registry.register(new Scheme("https", newSslSocketFactory(), 443));
return new SingleClientConnManager(getParams(), registry);
}
private SSLSocketFactory newSslSocketFactory() {
try {
// Get an instance of the Bouncy Castle KeyStore format
KeyStore trusted = KeyStore.getInstance("PKCS12", "BC");
// Get the raw resource, which contains the keystore with
// your trusted certificates (root and any intermediate certs)
InputStream in = App.getInstance().getAssets().open("server.crt");
// Initialize the keystore with the provided trusted certificates
// Also provide the password of the keystore
//trusted.load(in, "mysecret".toCharArray());
trusted.load(null, null);
CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
Certificate certificate = certificateFactory.generateCertificate(in);
trusted.setCertificateEntry("trust", certificate);
in.close();
// Pass the keystore to the SSLSocketFactory. The factory is responsible
// for the verification of the server certificate.
SSLSocketFactory sf = new SSLSocketFactory(trusted);
// Hostname verification from certificate
// http://hc.apache.org/httpcomponents-client-ga/tutorial/html/connmgmt.html#d4e506
//sf.setHostnameVerifier(SSLSocketFactory.STRICT_HOSTNAME_VERIFIER);
return sf;
} catch (Exception e) {
throw new AssertionError(e);
}
}
}注意：
1.部分android 的sdk里已自带BouncyCastleProvider提供的套件，如果没有，请下载并添加进去： ecurity.addProvider(new BouncyCastleProvider());
2.本文代码展示采用的HttpClient版本为httpcomponents-client-4.1.3，最新的api可能已经发生变化，某些api已经被Deprecated，请自行参考官方文档。
