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1: /* RSAPKCS1V1_5SignatureRawCodec.java -- Raw RSA PKCS1 v1.5 signature codeec 2: Copyright (C) 2006 Free Software Foundation, Inc. 3: 4: This file is 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, or (at your option) 9: 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; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 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.java.security.sig.rsa; 40: 41: import java.io.ByteArrayOutputStream; 42: 43: import gnu.java.security.Registry; 44: import gnu.java.security.sig.ISignatureCodec; 45: 46: /** 47: * An object that implements the {@link ISignatureCodec} operations for the 48: * <i>Raw</i> format to use with RSA-PKCS#1 v1.5 signatures. 49: */ 50: public class RSAPKCS1V1_5SignatureRawCodec 51: implements ISignatureCodec 52: { 53: public int getFormatID() 54: { 55: return RAW_FORMAT; 56: } 57: 58: /** 59: * Returns the encoded form of the designated RSA-PKCS#1 (v1.5) signature 60: * object according to the <i>Raw</i> format supported by this library. 61: * <p> 62: * The <i>Raw</i> format for such a signature, in this implementation, is a 63: * byte sequence consisting of the following: 64: * <p> 65: * <ol> 66: * <li>4-byte magic consisting of the value of the literal 67: * {@link Registry#MAGIC_RAW_RSA_PKCS1V1_5_SIGNATURE}, 68: * <li> 69: * <li>1-byte version consisting of the constant: 0x01,</li> 70: * <li>4-byte count of following bytes representing the RSA-PKCS#1 (v1.5) 71: * signature bytes in internet order,</li> 72: * <li>the RSA-PKCS#1 (v1.5) signature bytes in internet order.</li> 73: * </ol> 74: * 75: * @param signature the signature to encode, consisting of the output of the 76: * <code>sign()</code> method of a {@link RSAPKCS1V1_5Signature} 77: * instance --a byte array. 78: * @return the <i>Raw</i> format encoding of the designated signature. 79: * @exception IllegalArgumentException if the designated signature is not an 80: * RSA-PKCS#1 (v1.5) one. 81: */ 82: public byte[] encodeSignature(Object signature) 83: { 84: byte[] buffer; 85: try 86: { 87: buffer = (byte[]) signature; 88: } 89: catch (Exception x) 90: { 91: throw new IllegalArgumentException("Signature/codec mismatch"); 92: } 93: 94: ByteArrayOutputStream baos = new ByteArrayOutputStream(); 95: 96: // magic 97: baos.write(Registry.MAGIC_RAW_RSA_PKCS1V1_5_SIGNATURE[0]); 98: baos.write(Registry.MAGIC_RAW_RSA_PKCS1V1_5_SIGNATURE[1]); 99: baos.write(Registry.MAGIC_RAW_RSA_PKCS1V1_5_SIGNATURE[2]); 100: baos.write(Registry.MAGIC_RAW_RSA_PKCS1V1_5_SIGNATURE[3]); 101: 102: // version 103: baos.write(0x01); 104: 105: // signature bytes 106: int length = buffer.length; 107: baos.write( length >>> 24); 108: baos.write((length >>> 16) & 0xFF); 109: baos.write((length >>> 8) & 0xFF); 110: baos.write( length & 0xFF); 111: baos.write(buffer, 0, length); 112: 113: return baos.toByteArray(); 114: } 115: 116: /** 117: * Returns the decoded object from a designated input assumed to have been 118: * generated by the {@link #encodeSignature(Object)} method. 119: * 120: * @param input the input bytes of a previously Raw-encoded RSA PKCS1 (v1.5) 121: * signature. 122: * @return the signature object. 123: * @throws IllegalArgumentException if the designated input does not start 124: * with the right <i>magic</i> characters, or if the <i>version</i> 125: * is not supported. 126: */ 127: public Object decodeSignature(byte[] input) 128: { 129: // magic 130: if (input[0] != Registry.MAGIC_RAW_RSA_PKCS1V1_5_SIGNATURE[0] 131: || input[1] != Registry.MAGIC_RAW_RSA_PKCS1V1_5_SIGNATURE[1] 132: || input[2] != Registry.MAGIC_RAW_RSA_PKCS1V1_5_SIGNATURE[2] 133: || input[3] != Registry.MAGIC_RAW_RSA_PKCS1V1_5_SIGNATURE[3]) 134: throw new IllegalArgumentException("Signature/codec mismatch"); 135: 136: // version 137: if (input[4] != 0x01) 138: throw new IllegalArgumentException("Wrong or unsupported format version"); 139: 140: int i = 5; 141: int l; 142: 143: // signature bytes 144: l = input[i++] << 24 145: | (input[i++] & 0xFF) << 16 146: | (input[i++] & 0xFF) << 8 147: | (input[i++] & 0xFF); 148: byte[] result = new byte[l]; 149: System.arraycopy(input, i, result, 0, l); 150: 151: return result; 152: } 153: }