receivemail.java

用java实现的对电子邮件进行加密解密及签名的算法接口

package cn.edu.scut.smimeapi;
import javax.mail.*;
import java.util.*;
import java.io.*;
import org.bouncycastle.cms.SignerInformationStore;
import org.bouncycastle.mail.smime.SMIMESigned;
import java.security.cert.X509Certificate;
import org.bouncycastle.cms.SignerInformation;
import java.security.cert.CertStore;
import cn.edu.scut.certmgr.*;
import cn.edu.scut.certutils.Configure;
import java.security.Security;
import javax.activation.CommandMap;
import javax.activation.MailcapCommandMap;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
/**
 * <p>Title: </p>
 *
 * <p>Description: </p>
 *
 * <p>Copyright: Copyright (c) 2005</p>
 *
 * <p>Company: </p>
 *
 * @author lyh
 * @version 1.0
 */
public class ReceiveMail
{
  Folder inbox;
  Store store;

  static
   {
        /* Add BC */
        Security.addProvider(new BouncyCastleProvider());

     MailcapCommandMap mailcap = (MailcapCommandMap) CommandMap.getDefaultCommandMap();

              mailcap.addMailcap("application/pkcs7-signature;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.pkcs7_signature");
              mailcap.addMailcap("application/pkcs7-mime;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.pkcs7_mime");
              mailcap.addMailcap("application/x-pkcs7-signature;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.x_pkcs7_signature");
              mailcap.addMailcap("application/x-pkcs7-mime;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.x_pkcs7_mime");
              mailcap.addMailcap("multipart/signed;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.multipart_signed");

       CommandMap.setDefaultCommandMap(mailcap);

 }
  public ReceiveMail()
  {
    try
    {
      jbInit();
    }
    catch (Exception ex)
    {
      ex.printStackTrace();
    }
  }

  private void jbInit() throws Exception
  {

  }
//连接邮件服务器，获得所有邮件的列表
public Message[] getMail(String host,String name,String password)
throws Exception
{
Properties prop=new Properties();
prop.put("mail.pop3.host",host);
Session session=Session.getDefaultInstance(prop);
store=session.getStore("pop3");
store.connect(host,name,password);

inbox=store.getDefaultFolder().getFolder("INBOX");
inbox.open(Folder.READ_ONLY);

Message[] msg=inbox.getMessages();

FetchProfile profile=new FetchProfile();
profile.add(FetchProfile.Item.ENVELOPE);
inbox.fetch(msg,profile);

return(msg);
}

//处理任何一种邮件都需要的方法
public void handle(Message msg) throws Exception
{
System.out.println("邮件主题:"+msg.getSubject());
System.out.println("邮件作者:"+msg.getFrom()[0].toString());
System.out.println("发送日期:"+msg.getSentDate());
}

//处理普通的文本邮件
public void handleText(Message msg) throws Exception
{
this.handle(msg);
System.out.println("邮件内容:"+msg.getContent());
}

//处理普通的Multipart邮件，包括了保存附件的功能
public String handleMultipart(Message msg) throws Exception
{
String content=null;
String disposition;
BodyPart part;
Multipart mp=(Multipart)msg.getContent();
int mpCount=mp.getCount();//Miltipart的数量,用于除了多个part,比如多个附件
content="该邮件共有"+mpCount+"部分\n";
for(int m=0;m<mpCount;m++)
{
  part=mp.getBodyPart(m);
  disposition=part.getDisposition();
  content=content+"第"+(m+1)+"部分";
 if ((disposition != null) && ((disposition.equalsIgnoreCase(part.ATTACHMENT)) || (disposition.equalsIgnoreCase(part.INLINE))))//
 {
   String temp=part.getFileName();//得到未经处理的附件名字
   if((temp.startsWith("=?GBK?B?")&&temp.endsWith("?="))
           ||(temp.startsWith("=?gbk?b?")&&temp.endsWith("?=")))
        {
            temp=getFromBASE64(temp.substring(8,temp.indexOf("?=")));
        }else
        {
            temp=toChinese(temp);
        }

   //String s=temp.substring(11,temp.indexOf("?=")-1);//去到header和footer

   //文件名一般都经过了base64编码,下面是解码
   // String fileName=this.base64Decoder(s);
  content=content+ "有附件: "+temp+" 已保存\n";
  this.saveAttach(part);//这个方法负责保存附件，注释掉是因为附件可能有病毒，请清理信箱之后再取掉注释
 }
 else
 {
  content=content+"内容: "+part.getContent()+"\n";
 }

}
    return content;
}

  //处理Multipart邮件，包括了保存附件的功能
  public String handleMultipart(Multipart msg) throws Exception
  {
      String content=null;
      String disposition;
      BodyPart part;
      Multipart mp=(Multipart)msg;
      int mpCount=mp.getCount();//Miltipart的数量,用于除了多个part,比如多个附件
      content="该邮件共有"+mpCount+"部分\n";
      for(int m=0;m<mpCount;m++)
      {
        part=mp.getBodyPart(m);
        disposition=part.getDisposition();
        content=content+"第"+(m+1)+"部分";
       if ((disposition != null) && ((disposition.equalsIgnoreCase(part.ATTACHMENT)) || (disposition.equalsIgnoreCase(part.INLINE))))//
       {
         String temp=part.getFileName();//得到未经处理的附件名字
         if((temp.startsWith("=?GBK?B?")&&temp.endsWith("?="))
            ||(temp.startsWith("=?gbk?b?")&&temp.endsWith("?=")))
         {
             temp=getFromBASE64(temp.substring(8,temp.indexOf("?=")));
         }else
         {
             temp=toChinese(temp);
         }

         //String s=temp.substring(11,temp.indexOf("?=")-1);//去到header和footer

         //文件名一般都经过了base64编码,下面是解码
         // String fileName=this.base64Decoder(s);
        content=content+ "有附件: "+temp+" 已保存\n";
        this.saveAttach(part);//这个方法负责保存附件，注释掉是因为附件可能有病毒，请清理信箱之后再取掉注释
       }
       else
       {
        content=content+"内容: "+part.getContent()+"\n";
       }

      }

      return content;
}
// save the attachment file
public void saveAttach(BodyPart part) throws Exception
{
String temp=part.getFileName();//得到未经处理的附件名字
//String s=temp.substring(temp.length(),temp.indexOf("?=")-1);//去到header和footer

//文件名一般都经过了base64编码,下面是解码
//String fileName=this.base64Decoder(s);
    if((temp.startsWith("=?GBK?B?")&&temp.endsWith("?="))
                ||(temp.startsWith("=?gbk?b?")&&temp.endsWith("?=")))
     {
                 temp=getFromBASE64(temp.substring(8,temp.indexOf("?=")));
     }
    else
     {
                 temp=toChinese(temp);
     }
InputStream in=part.getInputStream();
FileOutputStream writer=new FileOutputStream(new File(temp));
byte[] content=new byte[255];
int read=0;
while((read=in.read(content))!=-1)
{
 writer.write(content);
}
writer.close();
in.close();
}

//base64解码
public String getFromBASE64(String s) throws Exception
{
sun.misc.BASE64Decoder decoder = new sun.misc.BASE64Decoder();
byte[] b=decoder.decodeBuffer(s);

return(new String(b));
}

public static String toChinese(String strvalue){
        try{
          if(strvalue==null)
            return null;
          else{
            strvalue = new String(strvalue.getBytes("ISO8859_1"), "GBK");
            return strvalue;
          }
        }catch(Exception e){
          return null;
        }
      }

//关闭连接
public void close() throws Exception
{
if(inbox!=null)
{
 inbox.close(false);
}

if(store!=null)
{
 store.close();
}
}
  /**
   * verify the signature (assuming the cert is contained in the message)
   */
  public static String verify(SMIMESigned s)
      throws Exception
  {

    CertValidator certValidator=null;
    String Checkresult=new String("验证签名结果如下：\n\n");
    boolean checkCertLian= true;
   try
    {
      String[] CA_KEYSTORE_FILENAME = new String[] {
    "CACertificateStoreParam", "ConfigurationFileName"};

    String[] CA_KEYSTORE_NAME = new String[] {
    "CACertificateStoreParam", "KeyStoreName"};

    String[] CA_KEYSTORE_PWD = new String[] {
    "CACertificateStoreParam", "PWD"};
    Configure config = Configure.getInstance();
    CPathValidator cPathValidator = new CPathValidator();
    cPathValidator.setCaStoreManager(new CAStoreManager(config.getAttribute(CA_KEYSTORE_FILENAME), config.getAttribute(CA_KEYSTORE_NAME),config.getAttribute(CA_KEYSTORE_PWD).toCharArray()));
    certValidator = new CertValidator(cPathValidator);

    }
    catch (Exception ex)
    {
        ex.printStackTrace();
        certValidator = new CertValidator();
        checkCertLian=false;
    }

      // extract the information to verify the signatures.

      // certificates and crls that passed in the signature
      //
      CertStore   certs = s.getCertificatesAndCRLs("Collection", "BC");

      //
      // SignerInfo blocks which contain the signatures
      //
      SignerInformationStore  signers = s.getSignerInfos();

      Collection              c = signers.getSigners();
      Iterator                it = c.iterator();

      //
      // check each signer
      //
      while (it.hasNext())
      {
          SignerInformation   signer = (SignerInformation)it.next();
          Collection          certCollection = certs.getCertificates(signer.getSID());

          Iterator        certIt = certCollection.iterator();
          X509Certificate cert = (X509Certificate)certIt.next();

          if (signer.verify(cert, "BC"))
         {
          Checkresult=Checkresult+new String("邮件内容没有被篡改\n");
         }
         else
         {
         Checkresult=Checkresult+new String("邮件内容被篡改\n");
         }

          // verify the cert's validator
          //验证证书是否已撤销,因为要从网上查CRL，暂时屏蔽，直接输出信息

         /*
        try
          {

          boolean Certisrevoke=certValidator.IsRevoke(cert);

          if(Certisrevoke)
            Checkresult=Checkresult+"签名数字证书已被吊销\n";
          else
           Checkresult=Checkresult+"签名数字证书未被吊销\n";

          }
          catch (NullPointerException ex)
          {
          Checkresult=Checkresult+"不能确定签名数字证书的吊销信息\n";
          }
       */
      Checkresult=Checkresult+"签名数字证书没有被吊销\n";
      //验证证书是否过期
       try
       {
       cert.checkValidity(new java.util.Date());
       Checkresult=Checkresult+"签名数字证书未过期\n";
       }
       catch (Exception ex)
       {
       Checkresult=Checkresult+"签名数字证书已过期\n";
       }
//验证证书链
 if(checkCertLian)
 {

  try
      {
          certValidator.Validate(false, cert);
          Checkresult=Checkresult+new String("确实信任签名所用的数字证书\n");
      }
      catch(Exception ex)
      {
      Checkresult=Checkresult+new String("签名数字证书可信任\n");
      }

  }

 else

  Checkresult=Checkresult+new String("无法验证签名数字证书是否可信任\n");

   }

  return  Checkresult;
}



}