| /* IncomingMessage.java -- |
| Copyright (C) 2003, 2006 Free Software Foundation, Inc. |
| |
| This file is a part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or (at |
| your option) any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 |
| USA |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.javax.crypto.key; |
| |
| import gnu.java.security.Registry; |
| import gnu.java.security.key.IKeyPairCodec; |
| import gnu.java.security.key.dss.DSSKeyPairPKCS8Codec; |
| import gnu.java.security.key.dss.DSSKeyPairRawCodec; |
| import gnu.java.security.key.dss.DSSKeyPairX509Codec; |
| import gnu.java.security.key.rsa.RSAKeyPairPKCS8Codec; |
| import gnu.java.security.key.rsa.RSAKeyPairRawCodec; |
| import gnu.java.security.key.rsa.RSAKeyPairX509Codec; |
| import gnu.javax.crypto.key.dh.DHKeyPairPKCS8Codec; |
| import gnu.javax.crypto.key.dh.DHKeyPairRawCodec; |
| import gnu.javax.crypto.key.dh.DHKeyPairX509Codec; |
| import gnu.javax.crypto.key.srp6.SRPKeyPairRawCodec; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.UnsupportedEncodingException; |
| import java.math.BigInteger; |
| import java.security.PrivateKey; |
| import java.security.PublicKey; |
| |
| /** |
| * An implementation of an incoming message for use with key agreement |
| * protocols. |
| */ |
| public class IncomingMessage |
| { |
| /** The internal buffer stream containing the message's contents. */ |
| protected ByteArrayInputStream in; |
| /** The length of the message contents, according to its 4-byte header. */ |
| protected int length; |
| |
| /** |
| * Constructs an incoming message given the message's encoded form, including |
| * its header bytes. |
| * |
| * @param b the encoded form, including the header bytes, of an incoming |
| * message. |
| * @throws KeyAgreementException if the buffer is malformed. |
| */ |
| public IncomingMessage(byte[] b) throws KeyAgreementException |
| { |
| this(); |
| |
| if (b.length < 4) |
| throw new KeyAgreementException("message header too short"); |
| length = b[0] << 24 |
| | (b[1] & 0xFF) << 16 |
| | (b[2] & 0xFF) << 8 |
| | (b[3] & 0xFF); |
| if (length > Registry.SASL_BUFFER_MAX_LIMIT || length < 0) |
| throw new KeyAgreementException("message size limit exceeded"); |
| in = new ByteArrayInputStream(b, 4, length); |
| } |
| |
| /** Trivial private constructor for use by the class method. */ |
| private IncomingMessage() |
| { |
| super(); |
| } |
| |
| /** |
| * Returns an instance of a message given its encoded contents, excluding the |
| * message's header bytes. |
| * <p> |
| * Calls the method with the same name and three arguments as: |
| * <code>getInstance(raw, 0, raw.length)</code>. |
| * |
| * @param raw the encoded form, excluding the header bytes. |
| * @return a new instance of <code>IncomingMessage</code>. |
| */ |
| public static IncomingMessage getInstance(byte[] raw) |
| { |
| return getInstance(raw, 0, raw.length); |
| } |
| |
| /** |
| * Returns an instance of a message given its encoded contents, excluding the |
| * message's header bytes. |
| * |
| * @param raw the encoded form, excluding the header bytes. |
| * @param offset offset where to start using raw bytes from. |
| * @param len number of bytes to use. |
| * @return a new instance of <code>IncomingMessage</code>. |
| */ |
| public static IncomingMessage getInstance(byte[] raw, int offset, int len) |
| { |
| IncomingMessage result = new IncomingMessage(); |
| result.in = new ByteArrayInputStream(raw, offset, len); |
| return result; |
| } |
| |
| /** |
| * Converts two octets into the number that they represent. |
| * |
| * @param b the two octets. |
| * @return the length. |
| */ |
| public static int twoBytesToLength(byte[] b) throws KeyAgreementException |
| { |
| int result = (b[0] & 0xFF) << 8 | (b[1] & 0xFF); |
| if (result > Registry.SASL_TWO_BYTE_MAX_LIMIT) |
| throw new KeyAgreementException("encoded MPI size limit exceeded"); |
| return result; |
| } |
| |
| /** |
| * Converts four octets into the number that they represent. |
| * |
| * @param b the four octets. |
| * @return the length. |
| */ |
| public static int fourBytesToLength(byte[] b) throws KeyAgreementException |
| { |
| int result = b[0] << 24 |
| | (b[1] & 0xFF) << 16 |
| | (b[2] & 0xFF) << 8 |
| | (b[3] & 0xFF); |
| if (result > Registry.SASL_FOUR_BYTE_MAX_LIMIT || result < 0) |
| throw new KeyAgreementException("encoded entity size limit exceeded"); |
| return result; |
| } |
| |
| public boolean hasMoreElements() |
| { |
| return (in.available() > 0); |
| } |
| |
| /** |
| * Decodes a public key from the message. |
| * <p> |
| * See {@link OutgoingMessage#writePublicKey(java.security.PublicKey)} for |
| * more details on the internal format. |
| * |
| * @throws KeyAgreementException if an encoding size constraint is violated or |
| * a mismatch was detected in the encoding. |
| */ |
| public PublicKey readPublicKey() throws KeyAgreementException |
| { |
| if (in.available() < 5) |
| throw new KeyAgreementException("not enough bytes for a public key in message"); |
| byte[] elementLengthBytes = new byte[4]; |
| in.read(elementLengthBytes, 0, 4); |
| int elementLength = fourBytesToLength(elementLengthBytes); |
| if (in.available() < elementLength) |
| throw new KeyAgreementException("illegal public key encoding"); |
| int keyTypeAndFormatID = in.read() & 0xFF; |
| elementLength--; |
| byte[] kb = new byte[elementLength]; |
| in.read(kb, 0, elementLength); |
| // instantiate the right codec and decode |
| IKeyPairCodec kpc = getKeyPairCodec(keyTypeAndFormatID); |
| return kpc.decodePublicKey(kb); |
| } |
| |
| /** |
| * Decodes a private key from the message. |
| * <p> |
| * See {@link OutgoingMessage#writePrivateKey(java.security.PrivateKey)} for |
| * more details. |
| * |
| * @throws KeyAgreementException if an encoding size constraint is violated or |
| * a mismatch was detected in the encoding. |
| */ |
| public PrivateKey readPrivateKey() throws KeyAgreementException |
| { |
| if (in.available() < 5) |
| throw new KeyAgreementException("not enough bytes for a private key in message"); |
| byte[] elementLengthBytes = new byte[4]; |
| in.read(elementLengthBytes, 0, 4); |
| int elementLength = fourBytesToLength(elementLengthBytes); |
| if (in.available() < elementLength) |
| throw new KeyAgreementException("illegal private key encoding"); |
| int keyTypeAndFormatID = in.read() & 0xFF; |
| elementLength--; |
| byte[] kb = new byte[elementLength]; |
| in.read(kb, 0, elementLength); |
| // instantiate the right codec and decode |
| IKeyPairCodec kpc = getKeyPairCodec(keyTypeAndFormatID); |
| return kpc.decodePrivateKey(kb); |
| } |
| |
| /** |
| * Decodes an MPI from the current message's contents. |
| * |
| * @return a native representation of an MPI. |
| * @throws KeyAgreementException if an encoding exception occurs during the |
| * operation. |
| */ |
| public BigInteger readMPI() throws KeyAgreementException |
| { |
| if (in.available() < 2) |
| throw new KeyAgreementException("not enough bytes for an MPI in message"); |
| byte[] elementLengthBytes = new byte[2]; |
| in.read(elementLengthBytes, 0, 2); |
| int elementLength = twoBytesToLength(elementLengthBytes); |
| if (in.available() < elementLength) |
| throw new KeyAgreementException("illegal MPI encoding"); |
| byte[] element = new byte[elementLength]; |
| in.read(element, 0, element.length); |
| return new BigInteger(1, element); |
| } |
| |
| public String readString() throws KeyAgreementException |
| { |
| if (in.available() < 2) |
| throw new KeyAgreementException("not enough bytes for a text in message"); |
| byte[] elementLengthBytes = new byte[2]; |
| in.read(elementLengthBytes, 0, 2); |
| int elementLength = twoBytesToLength(elementLengthBytes); |
| if (in.available() < elementLength) |
| throw new KeyAgreementException("illegal text encoding"); |
| byte[] element = new byte[elementLength]; |
| in.read(element, 0, element.length); |
| String result = null; |
| try |
| { |
| result = new String(element, "UTF8"); |
| } |
| catch (UnsupportedEncodingException x) |
| { |
| throw new KeyAgreementException("unxupported UTF8 encoding", x); |
| } |
| return result; |
| } |
| |
| private IKeyPairCodec getKeyPairCodec(int keyTypeAndFormatID) |
| throws KeyAgreementException |
| { |
| int keyType = (keyTypeAndFormatID >>> 4) & 0x0F; |
| int formatID = keyTypeAndFormatID & 0x0F; |
| switch (formatID) |
| { |
| case Registry.RAW_ENCODING_ID: |
| switch (keyType) |
| { |
| case 0: |
| return new DSSKeyPairRawCodec(); |
| case 1: |
| return new RSAKeyPairRawCodec(); |
| case 2: |
| return new DHKeyPairRawCodec(); |
| case 3: |
| return new SRPKeyPairRawCodec(); |
| default: |
| throw new KeyAgreementException("Unknown key-type for Raw format: " |
| + keyType); |
| } |
| case Registry.X509_ENCODING_ID: |
| switch (keyType) |
| { |
| case 0: |
| return new DSSKeyPairX509Codec(); |
| case 1: |
| return new RSAKeyPairX509Codec(); |
| case 2: |
| return new DHKeyPairX509Codec(); |
| default: |
| throw new KeyAgreementException("Unknown key-type for X.509 format: " |
| + keyType); |
| } |
| case Registry.PKCS8_ENCODING_ID: |
| switch (keyType) |
| { |
| case 0: |
| return new DSSKeyPairPKCS8Codec(); |
| case 1: |
| return new RSAKeyPairPKCS8Codec(); |
| case 2: |
| return new DHKeyPairPKCS8Codec(); |
| default: |
| throw new KeyAgreementException("Unknown key-type for PKCS#8 format: " |
| + keyType); |
| } |
| default: |
| throw new KeyAgreementException("Unknown format identifier: " |
| + formatID); |
| } |
| } |
| } |