/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 *

 *  (C) Copyright IBM Corp. 1999 All Rights Reserved.

 *  Copyright 1997 The Open Group Research Institute.  All rights reserved.

 */

package sun.security.krb5.internal.ccache;

import java.io.IOException;

import java.io.InputStream;

import java.util.ArrayList;

import java.util.List;

import java.util.StringTokenizer;

import sun.security.krb5.*;

import sun.security.krb5.internal.*;

import sun.security.krb5.internal.util.KrbDataInputStream;

import sun.security.util.IOUtils;

/**

 * This class extends KrbDataInputStream. It is used for parsing FCC-format

 * data from file to memory.

 *

 * @author Yanni Zhang

 *

 */

public class CCacheInputStream extends KrbDataInputStream implements FileCCacheConstants {

    /*

     * FCC version 2 contains type information for principals.  FCC

     * version 1 does not.

     *

     * FCC version 3 contains keyblock encryption type information, and is

     * architecture independent.  Previous versions are not.

     *

     * The code will accept version 1, 2, and 3 ccaches, and depending

     * what KRB5_FCC_DEFAULT_FVNO is set to, it will create version 1, 2,

     * or 3 FCC caches.

     *

     * The default credentials cache should be type 3 for now (see

     * init_ctx.c).

     */

    /* V4 of the credentials cache format allows for header tags */

    private static boolean DEBUG = Krb5.DEBUG;

    public CCacheInputStream(InputStream is){

        super(is);

    }

    /* Read tag field introduced in KRB5_FCC_FVNO_4 */

    // this needs to be public for Kinit.

    public Tag readTag() throws IOException {

        char[] buf = new char[1024];

        int len;

        int tag = -1;

        int taglen;

        Integer time_offset = null;

        Integer usec_offset = null;

        len = read(2);

        if (len < 0) {

            throw new IOException("stop.");

        }

        if (len > buf.length) {

            throw new IOException("Invalid tag length.");

        }

        while (len > 0) {

            tag    = read(2);

            taglen = read(2);

            switch (tag) {

            case FCC_TAG_DELTATIME:

                time_offset = read(4);

                usec_offset = read(4);

                break;

            default:

            }

            len = len - (4 + taglen);

        }

        return new Tag(len, tag, time_offset, usec_offset);

    }

    /*

     * In file-based credential cache, the realm name is stored as part of

     * principal name at the first place.

     */

    // made public for KinitOptions to call directly

    public PrincipalName readPrincipal(int version) throws IOException, RealmException {

        int type, length, namelength, kret;

        String[] pname = null;

        String realm;

        /* Read principal type */

        if (version == KRB5_FCC_FVNO_1) {

            type = KRB5_NT_UNKNOWN;

        } else {

            type = read(4);

        }

        length = readLength4();

        List<String> result = new ArrayList<String>();

        /*

         * DCE includes the principal's realm in the count; the new format

         * does not.

         */

        if (version == KRB5_FCC_FVNO_1)

            length--;

        for (int i = 0; i <= length; i++) {

            namelength = readLength4();

            byte[] bytes = IOUtils.readFully(this, namelength, true);

            result.add(new String(bytes));

        }

        if (result.isEmpty()) {

            throw new IOException("No realm or principal");

        }

        if (isRealm(result.get(0))) {

            realm = result.remove(0);

            if (result.isEmpty()) {

                throw new IOException("No principal name components");

            }

            return new PrincipalName(

                    type,

                    result.toArray(new String[result.size()]),

                    new Realm(realm));

        }

        try {

            return new PrincipalName(

                    type,

                    result.toArray(new String[result.size()]),

                    Realm.getDefault());

        } catch (RealmException re) {

            return null;

        }

    }

    /*

     * In practice, a realm is named by uppercasing the DNS domain name. we currently

     * rely on this to determine if the string within the principal identifier is realm

     * name.

     *

     */

    boolean isRealm(String str) {

        try {

            Realm r = new Realm(str);

        }

        catch (Exception e) {

            return false;

        }

        StringTokenizer st = new StringTokenizer(str, ".");

        String s;

        while (st.hasMoreTokens()) {

            s = st.nextToken();

            for (int i = 0; i < s.length(); i++) {

                if (s.charAt(i) >= 141) {

                    return false;

                }

            }

        }

        return true;

    }

    EncryptionKey readKey(int version) throws IOException {

        int keyType, keyLen;

        keyType = read(2);

        if (version == KRB5_FCC_FVNO_3)

            read(2); /* keytype recorded twice in fvno 3 */

        keyLen = readLength4();

        byte[] bytes = IOUtils.readFully(this, keyLen, true);

        return new EncryptionKey(bytes, keyType, version);

    }

    long[] readTimes() throws IOException {

        long[] times = new long[4];

        times[0] = (long)read(4) * 1000;

        times[1] = (long)read(4) * 1000;

        times[2] = (long)read(4) * 1000;

        times[3] = (long)read(4) * 1000;

        return times;

    }

    boolean readskey() throws IOException {

        if (read() == 0) {

            return false;

        }

        else return true;

    }

    HostAddress[] readAddr() throws IOException, KrbApErrException {

        int numAddrs, addrType, addrLength;

        numAddrs = readLength4();

        if (numAddrs > 0) {

            List<HostAddress> addrs = new ArrayList<>();

            for (int i = 0; i < numAddrs; i++) {

                addrType = read(2);

                addrLength = readLength4();

                if (!(addrLength == 4 || addrLength == 16)) {

                    if (DEBUG) {

                        System.out.println("Incorrect address format.");

                    }

                    return null;

                }

                byte[] result = new byte[addrLength];

                for (int j = 0; j < addrLength; j++)

                    result[j] = (byte)read(1);

                addrs.add(new HostAddress(addrType, result));

            }

            return addrs.toArray(new HostAddress[addrs.size()]);

        }

        return null;

    }

    AuthorizationDataEntry[] readAuth() throws IOException {

        int num, adtype, adlength;

        num = readLength4();

        if (num > 0) {

            List<AuthorizationDataEntry> auData = new ArrayList<>();

            byte[] data = null;

            for (int i = 0; i < num; i++) {

                adtype = read(2);

                adlength = readLength4();

                data = IOUtils.readFully(this, adlength, true);

                auData.add(new AuthorizationDataEntry(adtype, data));

            }

            return auData.toArray(new AuthorizationDataEntry[auData.size()]);

        }

        else return null;

    }

    byte[] readData() throws IOException {

        int length;

        length = readLength4();

        if (length == 0) {

            return null;

        } else {

            return IOUtils.readFully(this, length, true);

        }

    }

    boolean[] readFlags() throws IOException {

        boolean[] flags = new boolean[Krb5.TKT_OPTS_MAX+1];

        int ticketFlags;

        ticketFlags = read(4);

        if ((ticketFlags & 0x40000000) == TKT_FLG_FORWARDABLE)

        flags[1] = true;

        if ((ticketFlags & 0x20000000) == TKT_FLG_FORWARDED)

        flags[2] = true;

        if ((ticketFlags & 0x10000000) == TKT_FLG_PROXIABLE)

        flags[3] = true;

        if ((ticketFlags & 0x08000000) == TKT_FLG_PROXY)

        flags[4] = true;

        if ((ticketFlags & 0x04000000) == TKT_FLG_MAY_POSTDATE)

        flags[5] = true;

        if ((ticketFlags & 0x02000000) == TKT_FLG_POSTDATED)

        flags[6] = true;

        if ((ticketFlags & 0x01000000) == TKT_FLG_INVALID)

        flags[7] = true;

        if ((ticketFlags & 0x00800000) == TKT_FLG_RENEWABLE)

        flags[8] = true;

        if ((ticketFlags & 0x00400000) == TKT_FLG_INITIAL)

        flags[9] = true;

        if ((ticketFlags & 0x00200000) == TKT_FLG_PRE_AUTH)

        flags[10] = true;

        if ((ticketFlags & 0x00100000) == TKT_FLG_HW_AUTH)

        flags[11] = true;

        if (DEBUG) {

            String msg = ">>> CCacheInputStream: readFlags() ";

            if (flags[1] == true) {

                msg += " FORWARDABLE;";

            }

            if (flags[2] == true) {

                msg += " FORWARDED;";

            }

            if (flags[3] == true) {

                msg += " PROXIABLE;";

            }

            if (flags[4] == true) {

                msg += " PROXY;";

            }

            if (flags[5] == true) {

                msg += " MAY_POSTDATE;";

            }

            if (flags[6] == true) {

                msg += " POSTDATED;";

            }

            if (flags[7] == true) {

                msg += " INVALID;";

            }

            if (flags[8] == true) {

                msg += " RENEWABLE;";

            }

            if (flags[9] == true) {

                msg += " INITIAL;";

            }

            if (flags[10] == true) {

                msg += " PRE_AUTH;";

            }

            if (flags[11] == true) {

                msg += " HW_AUTH;";

            }

            System.out.println(msg);

        }

        return flags;

    }

    /**

     *

     */

        PrincipalName cpname = null;

        try {

            cpname = readPrincipal(version);

        } catch (Exception e) {

            // Do not return here. All data for this cred should be fully

            // consumed so that we can read the next one.

        }

        if (DEBUG) {

            System.out.println(">>>DEBUG <CCacheInputStream>  client principal is " + cpname);

        }

        PrincipalName spname = null;

        try {

            spname = readPrincipal(version);

        } catch (Exception e) {

            // same as above

        }

        if (DEBUG) {

            System.out.println(">>>DEBUG <CCacheInputStream> server principal is " + spname);

        }

        EncryptionKey key = readKey(version);

        if (DEBUG) {

            System.out.println(">>>DEBUG <CCacheInputStream> key type: " + key.getEType());

        }

        long[] times = readTimes();

        KerberosTime authtime = new KerberosTime(times[0]);

        KerberosTime starttime =

                (times[1]==0) ? null : new KerberosTime(times[1]);

        KerberosTime endtime = new KerberosTime(times[2]);

        KerberosTime renewTill =

                (times[3]==0) ? null : new KerberosTime(times[3]);

        if (DEBUG) {

            System.out.println(">>>DEBUG <CCacheInputStream> auth time: " + authtime.toDate().toString());

            System.out.println(">>>DEBUG <CCacheInputStream> start time: " +

                    ((starttime==null)?"null":starttime.toDate().toString()));

            System.out.println(">>>DEBUG <CCacheInputStream> end time: " + endtime.toDate().toString());

            System.out.println(">>>DEBUG <CCacheInputStream> renew_till time: " +

                    ((renewTill==null)?"null":renewTill.toDate().toString()));

        }

        boolean skey = readskey();

        boolean[] flags = readFlags();

        TicketFlags tFlags = new TicketFlags(flags);

        HostAddress[] addr = readAddr();

        HostAddresses addrs = null;

        if (addr != null) {

            addrs = new HostAddresses(addr);

        }

        AuthorizationDataEntry[] auDataEntry = readAuth();

        AuthorizationData auData = null;

        if (auDataEntry != null) {

            auData = new AuthorizationData(auDataEntry);

        }

        byte[] ticketData = readData();

        byte[] ticketData2 = readData();

        // Skip this cred if either cpname or spname isn't created.

        if (cpname == null || spname == null) {

            return null;

        }

        try {

            return new Credentials(cpname, spname, key, authtime, starttime,

        } catch (Exception e) {     // If any of new Ticket(*) fails.

            return null;

        }

    }

}