JAAS Kerberos 没有像我预期的那样从 keytab 添加密钥

JAAS Kerberos not adding keys from keytab as I expect

所以我正在尝试为 AIX 服务器(即 IBM JRE)实施 SSO/Integrated 安全系统。它使用 Kerberos 对 AD 进行身份验证。

请记住以下数据已经过清理。

命令我的 AD 管理员用于在 AD 服务器上创建密钥表文件(注意 /kvno 2)。

ktpass /princ HTTP/local.domain.com@LOCALDOMAIN.NET /mapuser PSLDAP@LOCALDOMAIN.NET /pass <PASSWORD> /crypto ALL /ptype KRB5_NT_PRINCIPAL /kvno 2 /out krb5.keytab

我的 krb5.conf 文件:

[libdefaults]
    default_realm = LOCALDOMAIN.NET
    default_keytab_name = FILE:/keytabs/krb.keytab
    default_tkt_enctypes = rc4-hmac
    default_tgs_enctypes = rc4-hmac
    dns_lookup_kdc = true
    dns_lookup_realm = true
[realms]
    LOCALDOMAIN.NET = {
            kdc = localdc08.localdomain.net:88
            kdc = otherdc08.localdomain.net:88
            admin_server = localdc08.localdomain.net:749
            master_kdc = localdc08.localdomain.net
            default_domain = LOCALDOMAIN.NET
    }
[domain_realm]
    .LOCALDOMAIN.NET = LOCALDOMAIN.NET
    LOCALDOMAIN.NET = LOCALDOMAIN.NET
    localdc08.localdomain.net = LOCALDOMAIN.NET
    localdc08.localdomain.net = LOCALDOMAIN.NET
    localdomain.net = LOCALDOMAIN.NET
    .localdomain.net = LOCALDOMAIN.NET
[logging]
    kdc = FILE:/var/krb5/log/krb5kdc.log
    admin_server = FILE:/var/krb5/log/kadmin.log
    kadmin_local = FILE:/var/krb5/log/kadmin_local.log
    default = FILE:/var/krb5/log/krb5lib.log

这是我的 krb5Login.conf 登录模块:

krbServer {
    com.ibm.security.auth.module.Krb5LoginModule required 
    credsType=acceptor 
    refreshKrb5Config=true 
    principal="HTTP/local.domain.com" 
    useKeytab="/keytabs/krb5.keytab" 
    debug=true;
};

这是 java 我是 运行(因为 IP 不能透露全部内容)

        context = new LoginContext("krbServer");
        context.login();

        // Get server credentials
        Subject sub = context.getSubject();
        serverCred = Subject.doAs(sub, new PrivilegedExceptionAction<GSSCredential>() {
            public GSSCredential run() throws GSSException {
                // mechanism OID for SPNEGO authentication
                Oid spnegoOid = new Oid("1.3.6.1.5.5.2");

                // null name defaults to currently logged in name
                GSSCredential cred = authManager.createCredential(null,
                        GSSCredential.INDEFINITE_LIFETIME,
                        spnegoOid,
                        GSSCredential.ACCEPT_ONLY);
                return cred;
            }
        });
        context.logout();

当我调用上面的代码时,我得到以下调试输出:

Constructor With Arg: krbServer Version: 1.7.0 Home: /dev/jre
LoginContext Constructed
[JGSS_DBG_CRED]  Thread-2 JAAS config: debug=true
[JGSS_DBG_CRED]  Thread-2 JAAS config: principal=HTTP/local.domain.com
[JGSS_DBG_CRED]  Thread-2 JAAS config: credsType=accept only
[JGSS_DBG_CRED]  Thread-2 config: useDefaultCcache=false (default)
[JGSS_DBG_CRED]  Thread-2 config: useCcache=null
[JGSS_DBG_CRED]  Thread-2 config: useDefaultKeytab=false
[JGSS_DBG_CRED]  Thread-2 config: useKeytab=/keytabs/krb5.keytab
[KRB_DBG_CFG] Config:Thread-2:   ConfigFile: /etc/krb5/krb5.conf
[JGSS_DBG_CRED]  Thread-2 JAAS config: forwardable=false (default)
[JGSS_DBG_CRED]  Thread-2 JAAS config: renewable=false (default)
[JGSS_DBG_CRED]  Thread-2 JAAS config: proxiable=false (default)
[JGSS_DBG_CRED]  Thread-2 JAAS config: tryFirstPass=false (default)
[JGSS_DBG_CRED]  Thread-2 JAAS config: useFirstPass=false (default)
[JGSS_DBG_CRED]  Thread-2 JAAS config: moduleBanner=false (default)
[JGSS_DBG_CRED]  Thread-2 JAAS config: interactive login? no
[JGSS_DBG_CRED]  Thread-2 JAAS config: refreshKrb5Config = true
[KRB_DBG_CFG] Config:Thread-2:   ConfigFile: /etc/krb5/krb5.conf
[KRB_DBG_KDC] KdcComm:Thread-2:   >>> KdcAccessibility: reset
[KRB_DBG_KDC] KdcComm:Thread-2:   >>> KdcAccessibility: reset
[JGSS_DBG_CRED]  Thread-2 Try keytab for principal=HTTP/local.domain.com
[KRB_DBG_KTAB] KeyTab:Thread-2Loading the keytab file ...   >>> KeyTab: load() entry length: 73
[KRB_DBG_KTAB] KeyTableInputStream:Thread-2:   >>> KeyTabInputStream, readName(): LOCALDOMAIN.NET
[KRB_DBG_KTAB] KeyTableInputStream:Thread-2:   >>> KeyTabInputStream, readName(): HTTP
[KRB_DBG_KTAB] KeyTableInputStream:Thread-2:   >>> KeyTabInputStream, readName(): local.domain.com
[KRB_DBG_KDC] EncryptionKey:Thread-2:   >>> EncryptionKey: config default key type is rc4-hmac
[KRB_DBG_KTAB] KeyTab:Thread-2:   Added key: 23  version: 2
[KRB_DBG_KTAB] KeyTab:Thread-2:   Ordering keys wrt default_tkt_enctypes list
[JGSS_DBG_CRED]  Thread-2 No Kerberos creds in keytab for principal HTTP/local.domain.com
[JGSS_DBG_CRED]  Thread-2 Login successful
[JGSS_DBG_CRED]  Thread-2 kprincipal : HTTP/local.domain.com@LOCALDOMAIN.NET
[JGSS_DBG_CRED]  Thread-2 HTTP/local.domain.com@LOCALDOMAIN.NET added to Subject
[JGSS_DBG_CRED]  Thread-2 Attempting to add KeyTab to Subject for HTTP/local.domain.com@LOCALDOMAIN.NET
[JGSS_DBG_CRED]  Thread-2 find keys for HTTP/local.domain.com@LOCALDOMAIN.NET
[KRB_DBG_KTAB] KeyTab:Thread-2:   Added key: 23  version: 2
[KRB_DBG_KTAB] KeyTab:Thread-2:   Ordering keys wrt default_tkt_enctypes list
[JGSS_DBG_CRED]  Thread-2 No keys to add to Subject for HTTP/local.domain.com@LOCALDOMAIN.NET
LoginContext login() method executed
LoginContext getSubject() method executed
Subject doAs() method executed, serverCred Name: default Lifetime: 2147483647
[JGSS_DBG_CRED]  Thread-2 KeyTab is removed from subject
[JGSS_DBG_CRED]  Thread-2 KerberosKey Kerberos Principal HTTP/local.domain.com@LOCALDOMAIN.NETKey Version 2key EncryptionKey: keyType=23 keyBytes (hex dump)=
0000: <MASKED>

当我打电话给

        public String validate(String encToken) {
        byte[] token = Base64.decode(encToken);

        GSSContext authContext;
        try {
            authContext = authManager.createContext(serverCred);
            authContext.acceptSecContext(token, 0, token.length);
            if (authContext.isEstablished()) {
                return authContext.getSrcName().toString();
            }
        } catch (GSSException e) {
            // fall through to the return
        }

        return null;
    }
}

我发现在我的令牌上调用的 "acceptSecContext" 命令 return 是一个值。我的印象是 acceptSecContext 只有 return 是一个需要传回给发起者的值。但是,发起者并不期望返回响应。此外(更重要的是).isEstablished() 方法 returns false.

所以我的问题是

1) 上面的设置有什么问题吗?
2) 为什么调用context对象的login()方法会出现这种情况?

[JGSS_DBG_CRED]  Thread-2 Attempting to add KeyTab to Subject for HTTP/local.domain.com@LOCALDOMAIN.NET
    [JGSS_DBG_CRED]  Thread-2 find keys for HTTP/local.domain.com@LOCALDOMAIN.NET
    [KRB_DBG_KTAB] KeyTab:Thread-2:   Added key: 23  version: 2
    [KRB_DBG_KTAB] KeyTab:Thread-2:   Ordering keys wrt default_tkt_enctypes list
    [JGSS_DBG_CRED]  Thread-2 No keys to add to Subject for HTTP/local.domain.com@LOCALDOMAIN.NET

如果它找到密钥 23 版本 2,为什么它会说“没有要添加到 principal@domain 的 Subject 的密钥?为什么它不添加它找到的密钥?kvno= 有问题吗? 2?

3) 我已经进行了非常详尽的搜索,但我无法确定如何解析 acceptSecContext 的输出以找出 return 值是什么。我收到的 return 值(base-64 编码)是 oQcwBaADCgEC

编辑:更新。来自 acceptSecContext 十六进制值的 return 值为: 0xA1 0x07 0x30 0x05 0xA0 0x03 0x0A 0x01 0x02

从以下站点 (https://msdn.microsoft.com/en-us/library/ms995330.aspx#http-sso-2_topic2) 得知第一个十六进制值 (A1) 对应于一个 NegTokenTarg。这就说得通了。

下一个八位位组应该是长度(如果长度需要更多八位位组,则最高位为 1)。由于最高位为 0,因此长度为 7 个八位字节。退房。

下一个八位位组(0x30)表示一个Constructed SEQUENCE,下一个八位位组是SEQUENCE长度(0x05); 5 个八位字节,签出。

然后我们有 0xA0、0x03、0x0A、0x01,它们表示序列元素 0 (negResult)。

最后的八位字节 (0x02) 是枚举值,即 "rejected"。

所以我的令牌被拒绝了。我如何计算出 "why"?我想我需要让 AD 团队参与进来,以查明他们到底发生了什么。

您是否尝试过手动测试 kinit 和 SPN 提供的密钥表?同样在您的 jaas.conf 中,您可能会使用 useKeyTab=true 和 keyTab="keytab_filename"。但这可能是您的 IBM JDK.

特有的东西

我已经为遇到类似问题的其他人发现了这个问题。

事实证明,OID 没有工作。

对我的 java 检索服务器凭据的代码进行以下更改解决了问题:

    serverCred = Subject.doAs(sub, new PrivilegedExceptionAction<GSSCredential>() {
        public GSSCredential run() throws GSSException {
            // mechanism OID for SPNEGO authentication
            Oid spnegoOid = new Oid("1.3.6.1.5.5.2");

            // null name defaults to currently logged in name
            GSSCredential cred = authManager.createCredential(null,
                    GSSCredential.INDEFINITE_LIFETIME,
                    spnegoOid,
                    GSSCredential.ACCEPT_ONLY);
            cred.add(null, 
                    GSSCredential.INDEFINITE_LIFETIME,
                    GSSCredential.INDEFINITE_LIFETIME,
                    new Oid("1.2.840.113554.1.2.2"),
                    GSSCredential.ACCEPT_ONLY);
            return cred;
        }

我认为这与我没有来回协商任何事情(发起者和接受者)这一事实有关,所以 SPNEGO 从未真正有机会告诉发起者它喜欢什么机制以及什么是可用的,但是我的印象是 SPNEGO Oid 可以容纳许多不同的机制,所以我不太清楚它起作用的原因,但它起作用了。

附录:经过进一步研究,我找到了对这个问题的模糊引用,原因是 "Some functionality deep in the GSSCredential implementation in AIX"。所以你有它。