From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libjava/classpath/gnu/javax/crypto/mode/CTR.java | 168 +++++++++++++++++++++++ 1 file changed, 168 insertions(+) create mode 100644 libjava/classpath/gnu/javax/crypto/mode/CTR.java (limited to 'libjava/classpath/gnu/javax/crypto/mode/CTR.java') diff --git a/libjava/classpath/gnu/javax/crypto/mode/CTR.java b/libjava/classpath/gnu/javax/crypto/mode/CTR.java new file mode 100644 index 000000000..56ea58c25 --- /dev/null +++ b/libjava/classpath/gnu/javax/crypto/mode/CTR.java @@ -0,0 +1,168 @@ +/* CTR.java -- + Copyright (C) 2001, 2002, 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.mode; + +import gnu.java.security.Registry; +import gnu.java.security.util.Sequence; +import gnu.javax.crypto.cipher.IBlockCipher; + +import java.util.Arrays; +import java.util.Iterator; + +/** + * The implementation of the Counter Mode. + *

+ * The algorithm steps are formally described as follows: + * + * 

+ *     CTR Encryption: O[j] = E(K)(T[j]); for j = 1, 2...n;
+ *                     C[j] = P[j] ˆ O[j]; for j = 1, 2...n.
+ *     CTR Decryption: O[j] = E(K)(T[j]); for j = 1, 2...n;
+ *                     P[j] = C[j] ˆ O[j]; for j = 1, 2...n.
+ *
+ * + *

+ * where P is the plaintext, C is the ciphertext, + * E(K) is the underlying block cipher encryption function + * parametrised with the session key K, and T is + * the Counter. + *

+ * This implementation, uses a standard incrementing function with a step of 1, + * and an initial value similar to that described in the NIST document. + *

+ * References: + *

    + *
  1. + * Recommendation for Block Cipher Modes of Operation Methods and Techniques, + * Morris Dworkin.
    2. + *
+ */ +public class CTR + extends BaseMode + implements Cloneable +{ + private int off; + private byte[] counter, enc; + + /** + * Trivial package-private constructor for use by the Factory class. + * + * @param underlyingCipher the underlying cipher implementation. + * @param cipherBlockSize the underlying cipher block size to use. + */ + CTR(IBlockCipher underlyingCipher, int cipherBlockSize) + { + super(Registry.CTR_MODE, underlyingCipher, cipherBlockSize); + } + + /** + * Private constructor for cloning purposes. + * + * @param that the instance to clone. + */ + private CTR(CTR that) + { + this((IBlockCipher) that.cipher.clone(), that.cipherBlockSize); + } + + public Object clone() + { + return new CTR(this); + } + + public void setup() + { + if (modeBlockSize > cipherBlockSize) + throw new IllegalArgumentException("mode size exceeds cipher block size"); + off = 0; + counter = new byte[cipherBlockSize]; + int i = cipherBlockSize - 1; + int j = iv.length - 1; + while (i >= 0 && j >= 0) + counter[i--] = iv[j--]; + enc = new byte[cipherBlockSize]; + cipher.encryptBlock(counter, 0, enc, 0); + } + + public void teardown() + { + if (counter != null) + Arrays.fill(counter, (byte) 0); + if (enc != null) + Arrays.fill(enc, (byte) 0); + } + + public void encryptBlock(byte[] in, int i, byte[] out, int o) + { + ctr(in, i, out, o); + } + + public void decryptBlock(byte[] in, int i, byte[] out, int o) + { + ctr(in, i, out, o); + } + + public Iterator blockSizes() + { + return new Sequence(1, cipherBlockSize).iterator(); + } + + private void ctr(byte[] in, int inOffset, byte[] out, int outOffset) + { + for (int i = 0; i < modeBlockSize; i++) + { + out[outOffset++] = (byte)(in[inOffset++] ^ enc[off++]); + if (off == cipherBlockSize) + { + int j; + for (j = cipherBlockSize - 1; j >= 0; j--) + { + counter[j]++; + if ((counter[j] & 0xFF) != 0) + break; + } + if (j == 0) + counter[cipherBlockSize - 1]++; + off = 0; + cipher.encryptBlock(counter, 0, enc, 0); + } + } + } +} -- cgit v1.2.3