| /* |
| * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.security.provider; |
| |
| import java.math.BigInteger; |
| import java.security.DigestException; |
| import java.security.MessageDigest; |
| import java.security.NoSuchAlgorithmException; |
| import java.security.NoSuchProviderException; |
| import java.security.SecureRandomParameters; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| |
| public class HashDrbg extends AbstractHashDrbg { |
| |
| private static final byte[] ZERO = new byte[1]; |
| private static final byte[] ONE = new byte[]{1}; |
| |
| private MessageDigest digest; |
| |
| private byte[] v; |
| private byte[] c; |
| |
| public HashDrbg(SecureRandomParameters params) { |
| mechName = "Hash_DRBG"; |
| configure(params); |
| } |
| |
| /** |
| * This call, used by the constructors, instantiates the digest. |
| */ |
| @Override |
| protected void initEngine() { |
| try { |
| /* |
| * Use the local SUN implementation to avoid native |
| * performance overhead. |
| */ |
| digest = MessageDigest.getInstance(algorithm, "SUN"); |
| } catch (NoSuchProviderException | NoSuchAlgorithmException e) { |
| // Fallback to any available. |
| try { |
| digest = MessageDigest.getInstance(algorithm); |
| } catch (NoSuchAlgorithmException exc) { |
| throw new InternalError( |
| "internal error: " + algorithm + " not available.", exc); |
| } |
| } |
| } |
| |
| private byte[] hashDf(int requested, List<byte[]> inputs) { |
| return hashDf(digest, outLen, requested, inputs); |
| } |
| |
| /** |
| * A hash-based derivation function defined in NIST SP 800-90Ar1 10.3.1. |
| * The function is used inside Hash_DRBG, and can also be used as an |
| * approved conditioning function as described in 800-90B 6.4.2.2. |
| * |
| * Note: In each current call, requested is seedLen, therefore small, |
| * no need to worry about overflow. |
| * |
| * @param digest a {@code MessageDigest} object in reset state |
| * @param outLen {@link MessageDigest#getDigestLength} of {@code digest} |
| * @param requested requested output length, in bytes |
| * @param inputs input data |
| * @return the condensed/expanded output |
| */ |
| public static byte[] hashDf(MessageDigest digest, int outLen, |
| int requested, List<byte[]> inputs) { |
| // 1. temp = the Null string. |
| // 2. len = upper_int(no_of_bits_to_return / outLen) |
| int len = (requested + outLen - 1) / outLen; |
| byte[] temp = new byte[len * outLen]; |
| // 3. counter = 0x01 |
| int counter = 1; |
| |
| // 4. For i = 1 to len do |
| for (int i=0; i<len; i++) { |
| // 4.1 temp = temp |
| // || Hash (counter || no_of_bits_to_return || input_string). |
| digest.update((byte) counter); |
| digest.update((byte)(requested >> 21)); // requested*8 as int32 |
| digest.update((byte)(requested >> 13)); |
| digest.update((byte)(requested >> 5)); |
| digest.update((byte)(requested << 3)); |
| for (byte[] input : inputs) { |
| digest.update(input); |
| } |
| try { |
| digest.digest(temp, i * outLen, outLen); |
| } catch (DigestException e) { |
| throw new AssertionError("will not happen", e); |
| } |
| // 4.2 counter = counter + 1 |
| counter++; |
| } |
| // 5. requested_bits = leftmost (temp, no_of_bits_to_return). |
| return temp.length == requested? temp: Arrays.copyOf(temp, requested); |
| // 6. Return |
| } |
| |
| // This method is used by both instantiation and reseeding. |
| @Override |
| protected final synchronized void hashReseedInternal(List<byte[]> inputs) { |
| |
| // 800-90Ar1 10.1.1.2: Instantiate Process. |
| // 800-90Ar1 10.1.1.3: Reseed Process. |
| byte[] seed; |
| |
| // Step 2: seed = Hash_df (seed_material, seedlen). |
| if (v != null) { |
| // Step 1 of 10.1.1.3: Prepend 0x01 || V |
| inputs.add(0, ONE); |
| inputs.add(1, v); |
| seed = hashDf(seedLen, inputs); |
| } else { |
| seed = hashDf(seedLen, inputs); |
| } |
| |
| // Step 3. V = seed. |
| v = seed; |
| |
| // Step 4. C = Hash_df ((0x00 || V), seedlen). |
| inputs = new ArrayList<>(2); |
| inputs.add(ZERO); |
| inputs.add(v); |
| c = hashDf(seedLen, inputs); |
| |
| // Step 5. reseed_counter = 1. |
| reseedCounter = 1; |
| |
| //status(); |
| |
| // Step 6: Return |
| } |
| |
| private void status() { |
| if (debug != null) { |
| debug.println(this, "V = " + hex(v)); |
| debug.println(this, "C = " + hex(c)); |
| debug.println(this, "reseed counter = " + reseedCounter); |
| } |
| } |
| |
| /** |
| * Adds byte arrays into an existing one. |
| * |
| * @param out existing array |
| * @param data more arrays, can be of different length |
| */ |
| private static void addBytes(byte[] out, int len, byte[]... data) { |
| for (byte[] d: data) { |
| int dlen = d.length; |
| int carry = 0; |
| for (int i = 0; i < len; i++) { |
| int sum = (out[len - i - 1] & 0xff) + carry; |
| if (i < dlen) { |
| sum += (d[dlen - i - 1] & 0xff); |
| } |
| out[len - i - 1] = (byte) sum; |
| carry = sum >> 8; |
| if (i >= dlen - 1 && carry == 0) break; |
| } |
| } |
| } |
| |
| /** |
| * Generates a user-specified number of random bytes. |
| * |
| * @param result the array to be filled in with random bytes. |
| */ |
| @Override |
| public final synchronized void generateAlgorithm( |
| byte[] result, byte[] additionalInput) { |
| |
| if (debug != null) { |
| debug.println(this, "generateAlgorithm"); |
| } |
| |
| // 800-90Ar1 10.1.1.4: Hash_DRBG_Generate Process |
| |
| // Step 1: Check reseed_counter. Will not fail. Already checked in |
| // AbstractDrbg#engineNextBytes. |
| |
| // Step 2: additional_input |
| if (additionalInput != null) { |
| digest.update((byte)2); |
| digest.update(v); |
| digest.update(additionalInput); |
| addBytes(v, seedLen, digest.digest()); |
| } |
| |
| // Step 3. Hashgen (requested_number_of_bits, V). |
| hashGen(result, v); |
| |
| // Step 4. H = Hash (0x03 || V). |
| digest.update((byte)3); |
| digest.update(v); |
| byte[] h = digest.digest(); |
| |
| // Step 5. V = (V + H + C + reseed_counter) mod 2seedlen. |
| byte[] rcBytes; |
| if (reseedCounter < 256) { |
| rcBytes = new byte[]{(byte)reseedCounter}; |
| } else { |
| rcBytes = BigInteger.valueOf(reseedCounter).toByteArray(); |
| } |
| addBytes(v, seedLen, h, c, rcBytes); |
| |
| // Step 6. reseed_counter = reseed_counter + 1. |
| reseedCounter++; |
| |
| //status(); |
| |
| // Step 7: Return. |
| } |
| |
| // 800-90Ar1 10.1.1.4: Hashgen |
| private void hashGen(byte[] output, byte[] v) { |
| |
| // Step 2. data = V |
| byte[] data = v; |
| |
| // Step 3: W is output not filled |
| |
| // Step 4: For i = 1 to m |
| int pos = 0; |
| int len = output.length; |
| |
| while (len > 0) { |
| if (len < outLen) { |
| // Step 4.1 w = Hash (data). |
| // Step 4.2 W = W || w. |
| System.arraycopy(digest.digest(data), 0, output, pos, |
| len); |
| } else { |
| try { |
| // Step 4.1 w = Hash (data). |
| digest.update(data); |
| // Step 4.2 digest into right position, no need to cat |
| digest.digest(output, pos, outLen); |
| } catch (DigestException e) { |
| throw new AssertionError("will not happen", e); |
| } |
| } |
| len -= outLen; |
| if (len <= 0) { |
| // shortcut, so that data and pos needn't be updated |
| break; |
| } |
| // Step 4.3 data = (data + 1) mod 2^seedlen. |
| if (data == v) { |
| data = Arrays.copyOf(v, v.length); |
| } |
| addBytes(data, seedLen, ONE); |
| pos += outLen; |
| } |
| |
| // Step 5: No need to truncate |
| // Step 6: Return |
| } |
| } |