/*

 * Copyright (c) 1996, 2014, Oracle and/or its affiliates. All rights reserved.

 * 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.

 */

package sun.security.ssl;

import java.io.*;

import java.nio.*;

import javax.crypto.BadPaddingException;

import javax.net.ssl.*;

import sun.misc.HexDumpEncoder;

/**

 * {@code InputRecord} implementation for {@code SSLSocket}.

 *

 * @author David Brownell

 */

final class SSLSocketInputRecord extends InputRecord implements SSLRecord {

    private OutputStream deliverStream = null;

    private byte[] temporary = new byte[1024];

    // used by handshake hash computation for handshake fragment

    private byte prevType = -1;

    private int hsMsgOff = 0;

    private int hsMsgLen = 0;

    private boolean formatVerified = false;     // SSLv2 ruled out?

    private boolean hasHeader = false;          // Had read the record header

    SSLSocketInputRecord() {

        this.readAuthenticator = MAC.TLS_NULL;

    }

    @Override

    int bytesInCompletePacket(InputStream is) throws IOException {

        if (!hasHeader) {

            // read exactly one record

            int really = read(is, temporary, 0, headerSize);

            if (really < 0) {

                throw new EOFException("SSL peer shut down incorrectly");

            }

            hasHeader = true;

        }

        byte byteZero = temporary[0];

        int len = 0;

        /*

         * If we have already verified previous packets, we can

         * ignore the verifications steps, and jump right to the

         * determination.  Otherwise, try one last hueristic to

         * see if it's SSL/TLS.

         */

        if (formatVerified ||

                (byteZero == ct_handshake) || (byteZero == ct_alert)) {

            /*

             * Last sanity check that it's not a wild record

             */

            ProtocolVersion recordVersion =

                    ProtocolVersion.valueOf(temporary[1], temporary[2]);

            // check the record version

            checkRecordVersion(recordVersion, false);

            /*

             * Reasonably sure this is a V3, disable further checks.

             * We can't do the same in the v2 check below, because

             * read still needs to parse/handle the v2 clientHello.

             */

            formatVerified = true;

            /*

             * One of the SSLv3/TLS message types.

             */

            len = ((temporary[3] & 0xFF) << 8) +

                   (temporary[4] & 0xFF) + headerSize;

        } else {

            /*

             * Must be SSLv2 or something unknown.

             * Check if it's short (2 bytes) or

             * long (3) header.

             *

             * Internals can warn about unsupported SSLv2

             */

            boolean isShort = ((byteZero & 0x80) != 0);

            if (isShort && ((temporary[2] == 1) || (temporary[2] == 4))) {

                ProtocolVersion recordVersion =

                        ProtocolVersion.valueOf(temporary[3], temporary[4]);

                // check the record version

                checkRecordVersion(recordVersion, true);

                /*

                 * Client or Server Hello

                 */

                //

                // Short header is using here.  We reverse the code here

                // in case it it used in the future.

                //

                // int mask = (isShort ? 0x7F : 0x3F);

                // len = ((byteZero & mask) << 8) +

                //        (temporary[1] & 0xFF) + (isShort ? 2 : 3);

                //

                len = ((byteZero & 0x7F) << 8) + (temporary[1] & 0xFF) + 2;

            } else {

                // Gobblygook!

                throw new SSLException(

                        "Unrecognized SSL message, plaintext connection?");

            }

        }

        return len;

    }

    // destination.position() is zero.

    @Override

    Plaintext decode(InputStream is, ByteBuffer destination)

            throws IOException, BadPaddingException {

        if (isClosed) {

            return null;

        }

        if (!hasHeader) {

            // read exactly one record

            int really = read(is, temporary, 0, headerSize);

            if (really < 0) {

                throw new EOFException("SSL peer shut down incorrectly");

            }

            hasHeader = true;

        }

        Plaintext plaintext = null;

        if (!formatVerified) {

            formatVerified = true;

            /*

             * The first record must either be a handshake record or an

             * alert message. If it's not, it is either invalid or an

             * SSLv2 message.

             */

            if ((temporary[0] != ct_handshake) &&

                (temporary[0] != ct_alert)) {

                plaintext = handleUnknownRecord(is, temporary, destination);

            }

        }

        if (plaintext == null) {

            plaintext = decodeInputRecord(is, temporary, destination);

        }

        // The record header should has comsumed.

        hasHeader = false;

        return plaintext;

    }

    @Override

    void setDeliverStream(OutputStream outputStream) {

        this.deliverStream = outputStream;

    }

    // Note that destination may be null

    private Plaintext decodeInputRecord(InputStream is, byte[] header,

            ByteBuffer destination) throws IOException, BadPaddingException {

        byte contentType = header[0];

        byte majorVersion = header[1];

        byte minorVersion = header[2];

        int contentLen = ((header[3] & 0xFF) << 8) + (header[4] & 0xFF);

        //

        // Check for upper bound.

        //

        // Note: May check packetSize limit in the future.

        if (contentLen < 0 || contentLen > maxLargeRecordSize - headerSize) {

            throw new SSLProtocolException(

                "Bad input record size, TLSCiphertext.length = " + contentLen);

        }

        //

        // Read a complete record.

        //

        if (destination == null) {

            destination = ByteBuffer.allocate(headerSize + contentLen);

        }  // Otherwise, the destination buffer should have enough room.

        int dstPos = destination.position();

        destination.put(temporary, 0, headerSize);

        while (contentLen > 0) {

            int howmuch = Math.min(temporary.length, contentLen);

            int really = read(is, temporary, 0, howmuch);

            if (really < 0) {

                throw new EOFException("SSL peer shut down incorrectly");

            }

            destination.put(temporary, 0, howmuch);

            contentLen -= howmuch;

        }

        destination.flip();

        destination.position(dstPos + headerSize);

        if (debug != null && Debug.isOn("record")) {

             System.out.println(Thread.currentThread().getName() +

                    ", READ: " +

                    ProtocolVersion.valueOf(majorVersion, minorVersion) +

                    " " + Record.contentName(contentType) + ", length = " +

                    destination.remaining());

        }

        //

        // Decrypt the fragment

        //

        ByteBuffer plaintext =

            decrypt(readAuthenticator, readCipher, contentType, destination);

        if ((contentType != ct_handshake) && (hsMsgOff != hsMsgLen)) {

            throw new SSLProtocolException(

                    "Expected to get a handshake fragment");

        }

        //

        // handshake hashing

        //

        if (contentType == ct_handshake) {

            int pltPos = plaintext.position();

            int pltLim = plaintext.limit();

            int frgPos = pltPos;

            for (int remains = plaintext.remaining(); remains > 0;) {

                int howmuch;

                byte handshakeType;

                if (hsMsgOff < hsMsgLen) {

                    // a fragment of the handshake message

                    howmuch = Math.min((hsMsgLen - hsMsgOff), remains);

                    handshakeType = prevType;

                    hsMsgOff += howmuch;

                    if (hsMsgOff == hsMsgLen) {

                        // Now is a complete handshake message.

                        hsMsgOff = 0;

                        hsMsgLen = 0;

                    }

                } else {    // hsMsgOff == hsMsgLen, a new handshake message

                    handshakeType = plaintext.get();

                    int handshakeLen = ((plaintext.get() & 0xFF) << 16) |

                                       ((plaintext.get() & 0xFF) << 8) |

                                        (plaintext.get() & 0xFF);

                    plaintext.position(frgPos);

                    if (remains < (handshakeLen + 1)) { // 1: handshake type

                        // This handshake message is fragmented.

                        prevType = handshakeType;

                        hsMsgOff = remains - 4;         // 4: handshake header

                        hsMsgLen = handshakeLen;

                    }

                    howmuch = Math.min(handshakeLen + 4, remains);

                }

                plaintext.limit(frgPos + howmuch);

                if (handshakeType == HandshakeMessage.ht_hello_request) {

                    // omitted from handshake hash computation

                } else if ((handshakeType != HandshakeMessage.ht_finished) &&

                    (handshakeType != HandshakeMessage.ht_certificate_verify)) {

                    if (handshakeHash == null) {

                        // used for cache only

                        handshakeHash = new HandshakeHash(false);

                    }

                    handshakeHash.update(plaintext);

                } else {

                    // Reserve until this handshake message has been processed.

                    if (handshakeHash == null) {

                        // used for cache only

                        handshakeHash = new HandshakeHash(false);

                    }

                    handshakeHash.reserve(plaintext);

                }

                plaintext.position(frgPos + howmuch);

                plaintext.limit(pltLim);

                frgPos += howmuch;

                remains -= howmuch;

            }

            plaintext.position(pltPos);

        }

        return new Plaintext(contentType,

                majorVersion, minorVersion, -1, -1L, plaintext);

                // recordEpoch, recordSeq, plaintext);

    }

    private Plaintext handleUnknownRecord(InputStream is, byte[] header,

            ByteBuffer destination) throws IOException, BadPaddingException {

        byte firstByte = header[0];

        byte thirdByte = header[2];

        // Does it look like a Version 2 client hello (V2ClientHello)?

        if (((firstByte & 0x80) != 0) && (thirdByte == 1)) {

            /*

             * If SSLv2Hello is not enabled, throw an exception.

             */

            if (helloVersion != ProtocolVersion.SSL20Hello) {

                throw new SSLHandshakeException("SSLv2Hello is not enabled");

            }

            byte majorVersion = header[3];

            byte minorVersion = header[4];

            if ((majorVersion == ProtocolVersion.SSL20Hello.major) &&

                (minorVersion == ProtocolVersion.SSL20Hello.minor)) {

                /*

                 * Looks like a V2 client hello, but not one saying

                 * "let's talk SSLv3".  So we need to send an SSLv2

                 * error message, one that's treated as fatal by

                 * clients (Otherwise we'll hang.)

                 */

                deliverStream.write(SSLRecord.v2NoCipher);      // SSLv2Hello

                if (debug != null) {

                    if (Debug.isOn("record")) {

                         System.out.println(Thread.currentThread().getName() +

                                "Requested to negotiate unsupported SSLv2!");

                    }

                    if (Debug.isOn("packet")) {

                        Debug.printHex(

                                "[Raw write]: length = " +

                                SSLRecord.v2NoCipher.length,

                                SSLRecord.v2NoCipher);

                    }

                }

                throw new SSLException("Unsupported SSL v2.0 ClientHello");

            }

            int msgLen = ((header[0] & 0x7F) << 8) | (header[1] & 0xFF);

            if (destination == null) {

                destination = ByteBuffer.allocate(headerSize + msgLen);

            }

            destination.put(temporary, 0, headerSize);

            msgLen -= 3;            // had read 3 bytes of content as header

            while (msgLen > 0) {

                int howmuch = Math.min(temporary.length, msgLen);

                int really = read(is, temporary, 0, howmuch);

                if (really < 0) {

                    throw new EOFException("SSL peer shut down incorrectly");

                }

                destination.put(temporary, 0, howmuch);

                msgLen -= howmuch;

            }

            destination.flip();

            /*

             * If we can map this into a V3 ClientHello, read and

             * hash the rest of the V2 handshake, turn it into a

             * V3 ClientHello message, and pass it up.

             */

            destination.position(2);     // exclude the header

            if (handshakeHash == null) {

                // used for cache only

                handshakeHash = new HandshakeHash(false);

            }

            handshakeHash.update(destination);

            destination.position(0);

            ByteBuffer converted = convertToClientHello(destination);

            if (debug != null && Debug.isOn("packet")) {

                 Debug.printHex(

                        "[Converted] ClientHello", converted);

            }

            return new Plaintext(ct_handshake,

                majorVersion, minorVersion, -1, -1L, converted);

        } else {

            if (((firstByte & 0x80) != 0) && (thirdByte == 4)) {

                throw new SSLException("SSL V2.0 servers are not supported.");

            }

            throw new SSLException("Unsupported or unrecognized SSL message");

        }

    }

    // Read the exact bytes of data, otherwise, return -1.

    private static int read(InputStream is,

            byte[] buffer, int offset, int len) throws IOException {

        int n = 0;

        while (n < len) {

            int readLen = is.read(buffer, offset + n, len - n);

            if (readLen < 0) {

                return -1;

            }

            if (debug != null && Debug.isOn("packet")) {

                 Debug.printHex(

                        "[Raw read]: length = " + readLen,

                        buffer, offset + n, readLen);

            }

            n += readLen;

        }

        return n;

    }

}