}

    @Nested
    @DisplayName("getSubject edge cases")
    class SubjectTests {
        @Test
        @DisplayName("returns provided subject")
        void subject_non_null() {
            Subject s = new Subject();
            TestCredentials creds = new TestCredentials("X", false, false, s, false);
            assertSame(s, creds.getSubject());
        }

        @Test

            when(mock.getSubject()).thenReturn(subject);
            doNothing().when(mock).login();
        })) {
            KerberosCredentials credentials = new KerberosCredentials(LOGIN_CONTEXT_NAME);
            assertNotNull(credentials.getSubject());
            assertEquals(subject, credentials.getSubject());
        }
    }

    /**
     * Test constructor when login fails.

        } catch (IOException e) {
            throw new PACDecodingException("Malformed kerberos ticket", e);
        }

        Enumeration<?> fields = sequence.getObjects();
        while (fields.hasMoreElements()) {
            ASN1TaggedObject tagged = ASN1Util.as(ASN1TaggedObject.class, fields);

            switch (tagged.getTagNo()) {
            case 0: // Ticket Flags

    void setSubject_updatesSubject() {
        Kerb5Authenticator auth = new Kerb5Authenticator((Subject) null);
        assertNull(auth.getSubject());
        Subject subject = new Subject();
        auth.setSubject(subject);
        assertSame(subject, auth.getSubject());
    }

        this.cachedSubject = null;
    }

    @Override
    public synchronized Subject getSubject() {
        if (this.cachedSubject != null) {
            return this.cachedSubject;
        }

        try {
            log.debug("Logging on");
            LoginContext lc;

            Subject ps = super.getSubject();

            if (this.configuration != null) {

     */
    public KerberosCredentials(String loginContextName) throws LoginException {
        LoginContext lc = new LoginContext(loginContextName);
        lc.login();
        this.subject = lc.getSubject();
    }

    /**
     * Retrieves all Kerberos keys from the authenticated subject.
     *
     * @return array of KerberosKey objects
     */
    public KerberosKey[] getKeys() {

            }
        } catch (IOException e) {
            throw new PACDecodingException("Malformed kerberos ticket", e);
        }

        Enumeration<?> fields = sequence.getObjects();
        while (fields.hasMoreElements()) {
            ASN1TaggedObject tagged = ASN1Util.as(ASN1TaggedObject.class, fields);
            switch (tagged.getTagNo()) {
            case 0:// Kerberos version

    /**
     * Get the security subject associated with these credentials.
     * @return subject associated with the credentials
     */
    Subject getSubject();

    /**
     * Refresh the credentials.
     * @throws CIFSException if refresh fails
     */
    void refresh() throws CIFSException;

        } catch (IOException e) {
            throw new PACDecodingException("Malformed kerberos ticket", e);
        }

        this.authorizations = new ArrayList<>();
        Enumeration<?> authElements = authSequence.getObjects();
        while (authElements.hasMoreElements()) {
            ASN1Sequence authElement = ASN1Util.as(ASN1Sequence.class, authElements);

            }
            ASN1Sequence sequence = ASN1Sequence.getInstance(tagged, true);
            final Enumeration<ASN1Object> fields = sequence.getObjects();
            while (fields.hasMoreElements()) {
                tagged = (ASN1TaggedObject) fields.nextElement();
                switch (tagged.getTagNo()) {
                case 0: