| Frames | No Frames |
1: /* OutgoingMessage.java -- 2: Copyright (C) 2003, 2006 Free Software Foundation, Inc. 3: 4: This file is a part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2 of the License, or (at 9: your option) any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; if not, write to the Free Software 18: Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 19: USA 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package gnu.javax.crypto.key; 40: 41: import gnu.java.security.Registry; 42: import gnu.java.security.key.dss.DSSKey; 43: import gnu.java.security.key.rsa.GnuRSAKey; 44: import gnu.java.security.util.FormatUtil; 45: import gnu.javax.crypto.key.dh.GnuDHKey; 46: import gnu.javax.crypto.key.srp6.SRPKey; 47: 48: import java.io.ByteArrayOutputStream; 49: import java.io.UnsupportedEncodingException; 50: import java.security.Key; 51: import java.security.PrivateKey; 52: import java.security.PublicKey; 53: import java.math.BigInteger; 54: 55: /** 56: * An implementation of outgoing messages for use with key agreement protocols. 57: */ 58: public class OutgoingMessage 59: { 60: /** The internal output stream. */ 61: private ByteArrayOutputStream out; 62: 63: public OutgoingMessage() 64: { 65: super(); 66: 67: out = new ByteArrayOutputStream(); 68: } 69: 70: /** 71: * Returns the encoded form of the current message including the 4-byte length 72: * header. 73: * 74: * @throws KeyAgreementException if an encoding size constraint is violated. 75: */ 76: public byte[] toByteArray() throws KeyAgreementException 77: { 78: byte[] buffer = wrap(); 79: int length = buffer.length; 80: byte[] result = new byte[length + 4]; 81: result[0] = (byte)(length >>> 24); 82: result[1] = (byte)(length >>> 16); 83: result[2] = (byte)(length >>> 8); 84: result[3] = (byte) length; 85: System.arraycopy(buffer, 0, result, 4, length); 86: return result; 87: } 88: 89: /** 90: * Returns the encoded form of the current message excluding the 4-byte length 91: * header. 92: * 93: * @throws KeyAgreementException if an encoding size constraint is violated. 94: */ 95: public byte[] wrap() throws KeyAgreementException 96: { 97: int length = out.size(); 98: if (length > Registry.SASL_BUFFER_MAX_LIMIT || length < 0) 99: throw new KeyAgreementException("message content is too long"); 100: return out.toByteArray(); 101: } 102: 103: /** 104: * Encodes a public key into the message. 105: * <p> 106: * When a public key is encoded into an outgoing message, the byte array of 107: * the encoded key --according to its encoding/decoding format specified when 108: * the key was first instantiated-- are put in the message (a) preceeded by 109: * one byte representing both the type of key (upper 4-bit) and the identifier 110: * of the format used (lower 4-bit), and (b) preceeed by a 4-byte entity 111: * representing the total length, excluding these 4 bytes, of the bytes 112: * representing the encoded key and the one-byte representing the key-type and 113: * format; i.e. 114: * <pre> 115: * key --> 4-byte-length || 1-byte-type-and-format || encoded-key-bytes 116: * </pre> 117: * 118: * @param k the public key to encode. 119: * @throws KeyAgreementException if an encoding size constraint is violated. 120: */ 121: public void writePublicKey(PublicKey k) throws KeyAgreementException 122: { 123: writeKey(k); 124: } 125: 126: /** 127: * Encodes a private key into the message. 128: * <p> 129: * When a private key is encoded into an outgoing message, the byte array of 130: * the encoded key --according to its encoding/decoding format specified when 131: * the key was first instantiated-- are put in the message (a) preceeded by 132: * one byte representing both the type of key (upper 4-bit) and the identifier 133: * of the format used (lower 4-bit), and (b) preceeed by a 4-byte entity 134: * representing the total length, excluding these 4 bytes, of the bytes 135: * representing the encoded key and the one-byte representing the key-type and 136: * format; i.e. 137: * <pre> 138: * key --> 4-byte-length || 1-byte-type-and-format || encoded-key-bytes 139: * </pre> 140: * 141: * @param k the private key to encode. 142: * @throws KeyAgreementException if an encoding size constraint is violated. 143: */ 144: public void writePrivateKey(PrivateKey k) throws KeyAgreementException 145: { 146: writeKey(k); 147: } 148: 149: /** 150: * Encodes an MPI into the message. 151: * 152: * @param val the MPI to encode. 153: * @throws KeyAgreementException if an encoding size constraint is violated. 154: */ 155: public void writeMPI(BigInteger val) throws KeyAgreementException 156: { 157: byte[] b = val.toByteArray(); 158: int length = b.length; 159: if (length > Registry.SASL_TWO_BYTE_MAX_LIMIT) 160: throw new KeyAgreementException("MPI is too long"); 161: byte[] lengthBytes = { (byte)(length >>> 8), (byte) length }; 162: out.write(lengthBytes, 0, 2); 163: out.write(b, 0, b.length); 164: } 165: 166: /** 167: * Encodes a string into the message. 168: * 169: * @param s the string to encode. 170: * @throws KeyAgreementException if the UTF8 encoding is not supported on this 171: * platform, or if an encoding size constraint is violated. 172: */ 173: public void writeString(String s) throws KeyAgreementException 174: { 175: byte[] b = null; 176: try 177: { 178: b = s.getBytes("UTF8"); 179: } 180: catch (UnsupportedEncodingException x) 181: { 182: throw new KeyAgreementException("unxupported UTF8 encoding", x); 183: } 184: int length = b.length; 185: if (length > Registry.SASL_TWO_BYTE_MAX_LIMIT) 186: throw new KeyAgreementException("text too long"); 187: byte[] lengthBytes = { (byte)(length >>> 8), (byte) length }; 188: out.write(lengthBytes, 0, 2); 189: out.write(b, 0, b.length); 190: } 191: 192: /** 193: * @param k the key to encode. 194: * @throws KeyAgreementException if an encoding size constraint is violated. 195: */ 196: private void writeKey(Key k) throws KeyAgreementException 197: { 198: byte[] b = k.getEncoded(); 199: int keyType = getKeyType(k); 200: int formatID = FormatUtil.getFormatID(k.getFormat()); 201: int length = b.length + 1; 202: if (length > Registry.SASL_FOUR_BYTE_MAX_LIMIT) 203: throw new KeyAgreementException("Encoded key is too long"); 204: byte[] lengthBytes = { 205: (byte)(length >>> 24), 206: (byte)(length >>> 16), 207: (byte)(length >>> 8), 208: (byte) length }; 209: out.write(lengthBytes, 0, 4); 210: out.write(((keyType & 0x0F) << 4) | (formatID & 0x0F)); 211: out.write(b, 0, b.length); 212: } 213: 214: /** 215: * @param k the key to find an identifier for. 216: * @return an integer from <code>0</code> to <code>3</code> identifying 217: * the type of key. 218: * @throws KeyAgreementException if the designated key is of unknown or 219: * unsupported type. 220: */ 221: private int getKeyType(Key k) throws KeyAgreementException 222: { 223: if (k instanceof DSSKey) 224: return 0; 225: if (k instanceof GnuRSAKey) 226: return 1; 227: if (k instanceof GnuDHKey) 228: return 2; 229: if (k instanceof SRPKey) 230: return 3; 231: throw new KeyAgreementException("Unknown or unsupported key type: " 232: + k.getClass().getName()); 233: } 234: }