Could not connect to SMTP host,PKIX path building failed,unable to find valid certification path...

系统管理员 2022-07-20 12:30 337阅读 0赞

# java发邮件时遇到的问题 #

公司最近将邮件系统进行了升级，升级之后的邮件必须采用邮件加密传输通道。也就是ssl登录。

之前写的普通登录也将无法使用。今天在修改程序的过程中出现了一些问题，最终都顺利解决了，记录一下。

## 登录方式 ##

### 普通登录 ###

<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
            <property name="host" value="${mail.smtp.host}" />
            <property name="javaMailProperties">
                <props>
                    <prop key="mail.smtp.auth">${mail.smtp.auth}</prop>
                    <prop key="mail.smtp.timeout">${mail.smtp.timeout}</prop>
                </props>
            </property>
            <property name="username" value="${mail.smtp.username}" />
            <property name="password" value="${mail.smtp.password}" />
        </bean>

### ssl登录 ###

<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
            <property name="host" value="${mail.smtp.host}" />
            <property name="port" value="${mail.smtp.port}" />
            <property name="username" value="${mail.smtp.username}" />
            <property name="password" value="${mail.smtp.password}" />
            <property name="javaMailProperties">
                <props>
                    <prop key="mail.smtp.timeout">${mail.smtp.timeout}</prop>
                    <prop key="mail.smtp.auth">${mail.smtp.auth}</prop>
                    <prop key="mail.smtp.starttls.enable">${mail.smtp.starttls.enable}</prop>
                    <prop key="mail.smtp.socketFactory.port">${mail.smtp.port}</prop>
                    <prop key="mail.smtp.socketFactory.class">javax.net.ssl.SSLSocketFactory</prop>
                    <prop key="mail.smtp.socketFactory.fallback">false</prop>
                </props>
            </property>
    </bean>

### 配置文件 ###

#------------------------------------------------------------------------------------
    # 邮件服务的配置
    #------------------------------------------------------------------------------------
    #服务器
    mail.smtp.host=smtp.abc.com
    #端口号，QQ邮箱需要使用SSL，端口号465或587，其他邮箱默认的端口号：25
    mail.smtp.port=465
    #STARTTLS是对纯文本通信协议的扩展。它提供一种方式将纯文本连接升级为加密连接（TLS或SSL）
    mail.smtp.starttls.enable=true
    #是否需要验证密码
    mail.smtp.auth=true
    #超时时间
    mail.smtp.timeout=50000
    #------------------------------------------------------------------------------------
    # 加解密密钥 不能给出
    # 对用户名和密码都进行了加密 加解密工具在DESUtil中
    #------------------------------------------------------------------------------------
    #登陆用户名 我是随便写的
    mail.smtp.username=CBoch2LlydMW2432VYReDe4tjvJRstAmCoE123111
    #密码 qq为授权码 111111我是随便写的
    mail.smtp.password=avq5JeBiMuNr5F4wclLZZA==

## 改为ssl后遇到的问题 ##

Mail server connection failed; nested exception is javax.mail.MessagingException: Could not connect to SMTP host: smtp.abc.com, port: 465;
    
    nested exception is:
    javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target. Failed messages: javax.mail.MessagingException: Could not connect to SMTP host: smtp.abc.com, port: 465;
    
    nested exception is:
    javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

错误为：

1.  Could not connect to SMTP host: smtp.abc.com, port: 465
2.  PKIX path building failed
3.  unable to find valid certification path to requested target

其中1和2是由3引起的

现在问题就是解决

unable to find valid certification path to requested target

网上有两种解决方案

1 安装数字证书  
2 生成证书

我把公司的数字证书安装后没有解决问题，采用第二种方法解决

参考文献  
[http://www.tuicool.com/articles/zUjiIb][http_www.tuicool.com_articles_zUjiIb]

其中这篇文章中有一个地方在邮件系统中需要注意  
url需要加上端口号

![这里写图片描述][20160725112640069]

看到如下信息表示成功地生成了证书

![这里写图片描述][20160725112819916]

将生成的jssecacerts文件拷贝到%JAVA\_HONME%\\jre\\lib\\security\\目录下就ok了。

![这里写图片描述][20160725113202406]

# 附上InstallCert.java #

/* * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Sun Microsystems nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
    
    import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStream;
    import java.security.KeyStore;
    import java.security.MessageDigest;
    import java.security.cert.CertificateException;
    import java.security.cert.X509Certificate;
    
    import javax.net.ssl.SSLContext;
    import javax.net.ssl.SSLException;
    import javax.net.ssl.SSLSocket;
    import javax.net.ssl.SSLSocketFactory;
    import javax.net.ssl.TrustManager;
    import javax.net.ssl.TrustManagerFactory;
    import javax.net.ssl.X509TrustManager;
    
    public class InstallCert {
    
        public static void main(String[] args) throws Exception {
            String host;
            int port;
            char[] passphrase;
            if ((args.length == 1) || (args.length == 2)) {
                String[] c = args[0].split(":");
                host = c[0];
                port = (c.length == 1) ? 443 : Integer.parseInt(c[1]);
                String p = (args.length == 1) ? "changeit" : args[1];
                passphrase = p.toCharArray();
            } else {
                System.out
                        .println("Usage: java InstallCert <host>[:port] [passphrase]");
                return;
            }
    
            File file = new File("jssecacerts");
            if (file.isFile() == false) {
                char SEP = File.separatorChar;
                File dir = new File(System.getProperty("java.home") + SEP + "lib"
                        + SEP + "security");
                file = new File(dir, "jssecacerts");
                if (file.isFile() == false) {
                    file = new File(dir, "cacerts");
                }
            }
            System.out.println("Loading KeyStore " + file + "...");
            InputStream in = new FileInputStream(file);
            KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
            ks.load(in, passphrase);
            in.close();
    
            SSLContext context = SSLContext.getInstance("TLS");
            TrustManagerFactory tmf = TrustManagerFactory
                    .getInstance(TrustManagerFactory.getDefaultAlgorithm());
            tmf.init(ks);
            X509TrustManager defaultTrustManager = (X509TrustManager) tmf
                    .getTrustManagers()[0];
            SavingTrustManager tm = new SavingTrustManager(defaultTrustManager);
            context.init(null, new TrustManager[] { tm }, null);
            SSLSocketFactory factory = context.getSocketFactory();
    
            System.out
                    .println("Opening connection to " + host + ":" + port + "...");
            SSLSocket socket = (SSLSocket) factory.createSocket(host, port);
            socket.setSoTimeout(10000);
            try {
                System.out.println("Starting SSL handshake...");
                socket.startHandshake();
                socket.close();
                System.out.println();
                System.out.println("No errors, certificate is already trusted");
            } catch (SSLException e) {
                System.out.println();
                e.printStackTrace(System.out);
            }
    
            X509Certificate[] chain = tm.chain;
            if (chain == null) {
                System.out.println("Could not obtain server certificate chain");
                return;
            }
    
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    System.in));
    
            System.out.println();
            System.out.println("Server sent " + chain.length + " certificate(s):");
            System.out.println();
            MessageDigest sha1 = MessageDigest.getInstance("SHA1");
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            for (int i = 0; i < chain.length; i++) { 
                X509Certificate cert = chain[i];
                System.out.println(" " + (i + 1) + " Subject "
                        + cert.getSubjectDN());
                System.out.println(" Issuer " + cert.getIssuerDN());
                sha1.update(cert.getEncoded());
                System.out.println(" sha1 " + toHexString(sha1.digest()));
                md5.update(cert.getEncoded());
                System.out.println(" md5 " + toHexString(md5.digest()));
                System.out.println();
            }
    
            System.out
                    .println("Enter certificate to add to trusted keystore or 'q' to quit: [1]");
            String line = reader.readLine().trim();
            int k;
            try {
                k = (line.length() == 0) ? 0 : Integer.parseInt(line) - 1;
            } catch (NumberFormatException e) {
                System.out.println("KeyStore not changed");
                return;
            }
    
            X509Certificate cert = chain[k];
            String alias = host + "-" + (k + 1);
            ks.setCertificateEntry(alias, cert);
    
            OutputStream out = new FileOutputStream("jssecacerts");
            ks.store(out, passphrase);
            out.close();
    
            System.out.println();
            System.out.println(cert);
            System.out.println();
            System.out
                    .println("Added certificate to keystore 'jssecacerts' using alias '"
                            + alias + "'");
        }
    
        private static final char[] HEXDIGITS = "0123456789abcdef".toCharArray();
    
        private static String toHexString(byte[] bytes) {
            StringBuilder sb = new StringBuilder(bytes.length * 3);
            for (int b : bytes) {
                b &= 0xff;
                sb.append(HEXDIGITS[b >> 4]);
                sb.append(HEXDIGITS[b & 15]);
                sb.append(' ');
            }
            return sb.toString();
        }
    
        private static class SavingTrustManager implements X509TrustManager {
    
            private final X509TrustManager tm;
            private X509Certificate[] chain;
    
            SavingTrustManager(X509TrustManager tm) {
                this.tm = tm;
            }
    
            public X509Certificate[] getAcceptedIssuers() {
                throw new UnsupportedOperationException();
            }
    
            public void checkClientTrusted(X509Certificate[] chain, String authType)
                    throws CertificateException {
                throw new UnsupportedOperationException();
            }
    
            public void checkServerTrusted(X509Certificate[] chain, String authType)
                    throws CertificateException {
                this.chain = chain;
                tm.checkServerTrusted(chain, authType);
            }
        }
    
    }

# 注意 #

不能将在自己电脑上生成的jssecacerts文件拷贝到服务器上去，如果拷贝上去不会起作用，仍然会报错。  
服务器必须编译InstallCert.java，去生成jssecacerts文件。

# 参考文献 #

> 1.[解决PKIX问题：unable to find valid certification path to requested target][http_www.tuicool.com_articles_zUjiIb]
> 
> 2.[Java发邮件-QQ服务器认证（A secure connection is requiered(such as ssl)）][Java_-QQ_A secure connection is requiered_such as ssl]

[http_www.tuicool.com_articles_zUjiIb]: http://www.tuicool.com/articles/zUjiIb
[20160725112640069]: /images/20220719/2f324b3af6ac420097be538740847dc6.png
[20160725112819916]: /images/20220719/4fae0297287445e4970ef79c9e3eef13.png
[20160725113202406]: /images/20220719/31f25b96abb24f06990d224a3ed3dae1.png
[Java_-QQ_A secure connection is requiered_such as ssl]: http://blog.csdn.net/frankcheng5143/article/details/50436207