CAS 5.x搭建常见问题系列(2).PKIX path building failed

错误原因

---

服务端的证书是不安全的，Cas的客户端在调用时因为安全提醒造成调用失败。

CAS的客户端需要导入服务端的证书后，就正常了。

具体操作步骤如下：

1. 首先启动tomcat，看下之前搭建的cas server启动是否正常

双击D:\casoverlay\apache-tomcat-8.5.31\bin\startup.bat

访问 https://cas.example.org:8443/cas/login

如对对cas的搭建有疑问，可看文章《轻松搭建CAS 5.x系列文章》

·2. 创建生成证书的目录

cd D:\casoverlay
mkdir cert

-3. 创建文件InstallCert.java

具体内容如下：

import java.io.*;
import java.net.URL;

import java.security.*;
import java.security.cert.*;

import javax.net.ssl.*;

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();
        return new X509Certificate[0];
    }

    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);
    }
    }

}

-4. 编辑InstallCert.java

cd D:\casoverlay\cert
javac InstallCert.java

此时目录会生成对应的class文件

-5. 生成客户端证书

cd D:\casoverlay\cert
java InstallCert cas.example.org:8443

填写您的域名和端口，运行InstallCert。

运行过程中，出现了错误提示后，根据提示输入1，命令就自动生成了证书

D:\casoverlay\cert>java InstallCert cas.example.org:8443
Loading KeyStore C:\Program Files\Java\jre1.8.0_151\lib\security\cacerts...
Opening connection to cas.example.org:8443...
Starting SSL handshake...

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
        at sun.security.ssl.Alerts.getSSLException(Unknown Source)
        at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
        at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
        at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
        at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
        at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
        at sun.security.ssl.Handshaker.processLoop(Unknown Source)
        at sun.security.ssl.Handshaker.process_record(Unknown Source)
        at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
        at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
        at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
        at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
        at InstallCert.main(InstallCert.java:87)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertP
athBuilderException: unable to find valid certification path to requested target
        at sun.security.validator.PKIXValidator.doBuild(Unknown Source)
        at sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
        at sun.security.validator.Validator.validate(Unknown Source)
        at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
        at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
        at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
        at InstallCert$SavingTrustManager.checkServerTrusted(InstallCert.java:183)
        at sun.security.ssl.AbstractTrustManagerWrapper.checkServerTrusted(Unknown Source)
        ... 9 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to reques
ted target
        at sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
        at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
        at java.security.cert.CertPathBuilder.build(Unknown Source)
        ... 17 more

Server sent 1 certificate(s):

 1 Subject CN=cas.example.org, OU=casexampleorg, O=casexampleorg, L=casexampleorg, ST=casexampleorg, C=CN
   Issuer  CN=cas.example.org, OU=casexampleorg, O=casexampleorg, L=casexampleorg, ST=casexampleorg, C=CN
   sha1    6e 6f 9e 68 9b 17 00 cb 24 00 c6 dd 5b 3e 98 1c dd 93 3b 58
   md5     34 06 43 82 a3 89 30 73 77 37 e2 8b 22 2a a0 8a

Enter certificate to add to trusted keystore or 'q' to quit: [1]
1

[
[
  Version: V3
  Subject: CN=cas.example.org, OU=casexampleorg, O=casexampleorg, L=casexampleorg, ST=casexampleorg, C=CN
  Signature Algorithm: SHA256withRSA, OID = 1.2.840.113549.1.1.11

  Key:  Sun RSA public key, 2048 bits
  modulus: 1690620466251730075410187335527176539575574279164656191301268616376011867351755314109432788128763792853957685
509850737657313044903867516296492688699327787967525657153944349196906172329911432006555223477421064086655769564280443085
752416260227648518507908266556286126488172636414552577201541577021778173696705348205206800885112095634757232838095194599
467840130327744042458608666642772670848884551427300132389186144347259187506374891023727125201882125947109668529124319064
780959421387991371315373185390093486540418719240509126192650469625947655340408578607406180180595247169589979804514097709
6461946148979540598598705209
  public exponent: 65537
  Validity: [From: Fri Jun 29 23:49:33 CST 2018,
               To: Thu Sep 27 23:49:33 CST 2018]
  Issuer: CN=cas.example.org, OU=casexampleorg, O=casexampleorg, L=casexampleorg, ST=casexampleorg, C=CN
  SerialNumber: [    56261ad8]

Certificate Extensions: 1
[1]: ObjectId: 2.5.29.14 Criticality=false
SubjectKeyIdentifier [
KeyIdentifier [
0000: 45 84 BF 42 27 F5 B1 33   36 F4 6B CC 15 82 5D B0  E..B'..36.k...].
0010: AC AD 2A 9B                                        ..*.
]
]

]
  Algorithm: [SHA256withRSA]
  Signature:
0000: 0B C8 FA 28 E6 86 AC DE   FA 99 5C BE 96 B2 E3 00  ...(......\.....
0010: 2A 40 92 9C FF 44 D8 35   EF 3C 7C C2 DF 7A FB 9F  *@...D.5.<...z..
0020: 23 E0 AC 2B 8D 2A AD 18   60 FC B4 33 E1 06 54 DB  #..+.*..`..3..T.
0030: 51 C8 94 4D 61 1C 97 3D   63 07 13 C7 90 B3 26 D6  Q..Ma..=c.....&.
0040: 68 EB 87 D7 04 FA 36 14   FE 70 42 C9 25 90 CB 09  h.....6..pB.%...
0050: 07 4B 96 79 2D 29 F1 D5   29 57 90 71 32 09 AE A6  .K.y-)..)W.q2...
0060: 51 4F D9 79 09 D1 0D 84   F5 D4 C3 AE 71 A2 D3 28  QO.y........q..(
0070: B9 09 0C 21 DB 1E 37 33   3B CF 4A 0B 52 89 4A 4D  ...!..73;.J.R.JM
0080: 9D E4 40 8C 09 FA 93 77   5C 53 A5 D0 E0 DD C0 4F  ..@....w\S.....O
0090: 9B 30 0F C3 72 69 72 3D   90 90 20 30 5C 86 D2 A5  .0..rir=.. 0\...
00A0: 05 CF 9C 1D C3 2F 8E 1C   13 75 F2 A7 C3 65 92 61  ...../...u...e.a
00B0: 5C A9 DD C7 D6 90 6B 87   29 00 82 DD B3 28 05 AD  \.....k.)....(..
00C0: C8 BD EF 25 F3 5C 6C C9   50 62 C7 3B 8B 7B 8D 4D  ...%.\l.Pb.;...M
00D0: 92 DB D1 BE 87 D4 C3 F8   F4 5A FD 54 27 07 FF 18  .........Z.T'...
00E0: 14 C5 DB 77 A8 2D D8 38   58 0D 14 75 DC C1 61 42  ...w.-.8X..u..aB
00F0: 90 2E D1 94 B5 B9 9B FA   70 2F 25 3A 0D 61 8B 38  ........p/%:.a.8

]

Added certificate to keystore 'jssecacerts' using alias 'cas.example.org-1'

D:\casoverlay\cert>

-6. 检查下证书是否OK

重新运行运行InstallCert，就不会有错误提示了

java InstallCert cas.example.org:8443

-7. 最后一步，安装证书到客户端JVM

就是将生成的文件jssecacerts复制到 %java_home%\jre\lib\security目录下

-8. 重新启动，CAS 客户端登录下试试

如果操作正确，就没有错误了能正常登录了