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Diffstat (limited to 'gnu/javax/crypto/pad/PKCS1_V1_5.java')
-rw-r--r-- | gnu/javax/crypto/pad/PKCS1_V1_5.java | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/gnu/javax/crypto/pad/PKCS1_V1_5.java b/gnu/javax/crypto/pad/PKCS1_V1_5.java new file mode 100644 index 000000000..5b4f7b850 --- /dev/null +++ b/gnu/javax/crypto/pad/PKCS1_V1_5.java @@ -0,0 +1,184 @@ +/* PKCS1_V1_5.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.pad; + +import gnu.java.security.Registry; +import gnu.java.security.sig.rsa.EME_PKCS1_V1_5; +import gnu.java.security.util.Util; + +import java.io.PrintWriter; +import java.util.Random; + +/** + * <p>A padding algorithm implementation of the EME-PKCS1-V1.5 encoding/decoding + * algorithm as described in section 7.2 of RFC-3447. This is effectively an + * <i>Adapter</i> over an instance of {@link EME_PKCS1_V1_5} initialised with + * the RSA public shared modulus length (in bytes).</p> + * + * <p>References:</p> + * <ol> + * <li><a href="http://www.ietf.org/rfc/rfc3447.txt">Public-Key Cryptography + * Standards (PKCS) #1:</a><br> + * RSA Cryptography Specifications Version 2.1.<br> + * Jakob Jonsson and Burt Kaliski.</li> + * </ol> + * + * @see EME_PKCS1_V1_5 + */ +public class PKCS1_V1_5 extends BasePad +{ + + // Debugging methods and variables + // ------------------------------------------------------------------------- + + private static final String NAME = Registry.EME_PKCS1_V1_5_PAD; + + private static final boolean DEBUG = false; + + private static final int debuglevel = 9; + + private static final PrintWriter err = new PrintWriter(System.out, true); + + private static void debug(final String s) + { + err.println(">>> " + NAME + ": " + s); + } + + // Constants and variables + // ------------------------------------------------------------------------- + + private EME_PKCS1_V1_5 codec; + + // Constructor(s) + // ------------------------------------------------------------------------- + + /** + * <p>Trivial package-private constructor for use by the <i>Factory</i> class. + * </p> + * + * @see gnu.crypto.pad.PadFactory + */ + PKCS1_V1_5() + { + super(Registry.EME_PKCS1_V1_5_PAD); + } + + // Class methods + // ------------------------------------------------------------------------- + + // Implementation of abstract methods in BasePad + // ------------------------------------------------------------------------- + + public void setup() + { + codec = EME_PKCS1_V1_5.getInstance(blockSize); + } + + public byte[] pad(final byte[] in, final int offset, final int length) + { + final byte[] M = new byte[length]; + System.arraycopy(in, offset, M, 0, length); + final byte[] EM = codec.encode(M); + final byte[] result = new byte[blockSize - length]; + System.arraycopy(EM, 0, result, 0, result.length); + if (DEBUG && debuglevel > 8) + { + debug("padding: 0x" + Util.toString(result)); + } + return result; + } + + public int unpad(final byte[] in, final int offset, final int length) + throws WrongPaddingException + { + final byte[] EM = new byte[length]; + System.arraycopy(in, offset, EM, 0, length); + final int result = length - codec.decode(EM).length; + if (DEBUG && debuglevel > 8) + { + debug("padding length: " + String.valueOf(result)); + } + return result; + } + + // overloaded methods ------------------------------------------------------ + + public boolean selfTest() + { + final int[] mLen = new int[] { 16, 20, 32, 48, 64 }; + final byte[] M = new byte[mLen[mLen.length - 1]]; + new Random ().nextBytes(M); + final byte[] EM = new byte[1024]; + byte[] p; + int bs, i, j; + for (bs = 256; bs < 1025; bs += 256) + { + init(bs); + for (i = 0; i < mLen.length; i++) + { + j = mLen[i]; + p = pad(M, 0, j); + if (j + p.length != blockSize) + { + new RuntimeException(name()).printStackTrace(System.err); + return false; + } + + System.arraycopy(p, 0, EM, 0, p.length); + System.arraycopy(M, 0, EM, p.length, j); + try + { + if (p.length != unpad(EM, 0, blockSize)) + { + new RuntimeException(name()).printStackTrace(System.err); + return false; + } + } + catch (WrongPaddingException x) + { + x.printStackTrace(System.err); + return false; + } + } + reset(); + } + + return true; + } +}
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