/*
 * 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
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/*
 *
 *  (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/**
 * 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.readExactlyNBytes(this, namelength);
            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.readExactlyNBytes(this, keyLen);
        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.readExactlyNBytes(this, adlength);
                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.readExactlyNBytes(this, length);
        }
    }

    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;
    }

    
Reads the next cred or config entry in stream.
Returns:
the next cred or config entry, null if data unparseable.
When data is unparseable, this method makes sure the correct number of
bytes are consumed so it's safe to start reading the next element./**
     * Reads the next cred or config entry in stream.
     * @return the next cred or config entry, null if data unparseable.
     *
     * When data is unparseable, this method makes sure the correct number of
     * bytes are consumed so it's safe to start reading the next element.
     */
    Object readCred(int version) throws IOException,RealmException, KrbApErrException, Asn1Exception {
        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 {
            if (spname.getRealmString().equals("X-CACHECONF:")) {
                String[] nameParts = spname.getNameStrings();
                if (nameParts[0].equals("krb5_ccache_conf_data")) {
                    return new CredentialsCache.ConfigEntry(nameParts[1],
                            nameParts.length > 2 ? new PrincipalName(nameParts[2]) : null,
                            ticketData);
                }
            }
            return new Credentials(cpname, spname, key, authtime, starttime,
                    endtime, renewTill, skey, tFlags,
                    addrs, auData,
                    ticketData != null ? new Ticket(ticketData) : null,
                    ticketData2 != null ? new Ticket(ticketData2) : null);
        } catch (Exception e) {     // If any of new Ticket(*) fails.
            if (DEBUG) {
                e.printStackTrace(System.out);
            }
            return null;
        }
    }
}