前言：曾经听别人说生成证书时能够用IP地址。今天用样例证实了下用IP地址是不行的。

情景一：

生成证书时指定的名称为IP地址

样例是做单点登录时的样例。web.xml中配置例如以下：

<!--该过滤器负责用户的认证工作。必须启用它 -->
    <filter>
        <filter-name>CASFilter</filter-name>
        <filter-class>org.jasig.cas.client.authentication.AuthenticationFilter</filter-class>
        <init-param>
            <param-name>casServerLoginUrl</param-name>
            <param-value>https://172.18.113.78:8443/CasServer/login</param-value>
            <!--这里的server是服务端的IP -->
        </init-param>
        <init-param>
            <param-name>serverName</param-name>
            <param-value>http://127.0.0.1:8080/</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CASFilter</filter-name>
        <url-pattern>/*</url-pattern
    </filter-mapping>
 
    <!-- 该过滤器负责对Ticket的校验工作。必须启用它 -->
    <!-- ValidationFilter 这个filter负责对请求參数ticket进行验证(ticket參数是负责子系统与CAS进行验证交互的凭证)casServerUrlPrefix:CAS服务訪问地址serverName:当前应用所在的主机名 -->
    <filter>
        <filter-name>CAS Validation Filter</filter-name>
        <filter-class>
            org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter
        </filter-class>
        <init-param>
            <param-name>casServerUrlPrefix</param-name>
            <param-value>https://172.18.113.78:8443/CasServer</param-value>
        </init-param>
        <init-param>
            <param-name>serverName</param-name>
            <param-value>http://127.0.0.1:8080</param-value>
        </init-param>
        <init-param>
			<param-name>encoding</param-name>
			<param-value>UTF-8</param-value>
		</init-param>
    </filter>
    <filter-mapping>
        <filter-name>CAS Validation Filter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

如上配置中指定使用HTTPS协议，生成证书时指定的名称为上图中的172.18.113.78,訪问后出错，结果例如以下：

严重: Servlet.service() for servlet [jsp] in context with path [/uum] threw exception
java.lang.RuntimeException: javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No subject alternative names present
	at org.jasig.cas.client.util.CommonUtils.getResponseFromServer(CommonUtils.java:341)
	at org.jasig.cas.client.util.CommonUtils.getResponseFromServer(CommonUtils.java:305)
	at org.jasig.cas.client.validation.AbstractCasProtocolUrlBasedTicketValidator.retrieveResponseFromServer(AbstractCasProtocolUrlBasedTicketValidator.java:50)
	at org.jasig.cas.client.validation.AbstractUrlBasedTicketValidator.validate(AbstractUrlBasedTicketValidator.java:207)
	at org.jasig.cas.client.validation.AbstractTicketValidationFilter.doFilter(AbstractTicketValidationFilter.java:169)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.jasig.cas.client.authentication.AuthenticationFilter.doFilter(AuthenticationFilter.java:116)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.jasig.cas.client.session.SingleSignOutFilter.doFilter(SingleSignOutFilter.java:76)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at fi.common.filter.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:125)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:166)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:619)
Caused by: javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No subject alternative names present
	at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:174)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1591)
	at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:187)
	at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:181)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1035)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:124)
	at com.sun.net.ssl.internal.ssl.Handshaker.processLoop(Handshaker.java:516)
	at com.sun.net.ssl.internal.ssl.Handshaker.process_record(Handshaker.java:454)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:884)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1096)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1123)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1107)
	at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:415)
	at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:166)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1026)
	at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:234)
	at org.jasig.cas.client.util.CommonUtils.getResponseFromServer(CommonUtils.java:328)
	... 30 more
Caused by: java.security.cert.CertificateException: No subject alternative names present
	at sun.security.util.HostnameChecker.matchIP(HostnameChecker.java:142)
	at sun.security.util.HostnameChecker.match(HostnameChecker.java:75)
	at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkIdentity(X509TrustManagerImpl.java:264)
	at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:250)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1014)
	... 42 more

情景二：

生成证书时指定名称为域名（測试用的，改动了本地host文件）

样例同情景一中的样例，仅仅是把web.xml中的IP地址改为了域名，測试结果为通过。

假设client訪问出现例如以下错误：

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

这样的错误往往是证书路径不正确导致的。

可能原因一：tomcat使用的jdk和证书导入的jdk不是同一个

可能原因二：导入完毕后须要重新启动（静态导入），重新启动一次不行建议重新启动第二次

可能原因三：jdk中的证书导入错误

结论

所以得出结论，生成证书时须要指定域名而非用IP地址。