- /*
- * Copyright (C) 2017, Google Inc.
- * and other copyright owners as documented in the project's IP log.
- *
- * This program and the accompanying materials are made available
- * under the terms of the Eclipse Distribution License v1.0 which
- * accompanies this distribution, is reproduced below, and is
- * available at http://www.eclipse.org/org/documents/edl-v10.php
- *
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or
- * without modification, are permitted provided that the following
- * conditions are met:
- *
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * - Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following
- * disclaimer in the documentation and/or other materials provided
- * with the distribution.
- *
- * - Neither the name of the Eclipse Foundation, Inc. nor the
- * names of its contributors may be used to endorse or promote
- * products derived from this software without specific prior
- * written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
- * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
- package org.eclipse.jgit.util.sha1;
-
- import static java.nio.charset.StandardCharsets.UTF_8;
- import static org.junit.Assert.assertEquals;
- import static org.junit.Assert.assertTrue;
- import static org.junit.Assert.fail;
- import static org.junit.Assume.assumeTrue;
-
- import java.io.IOException;
- import java.io.InputStream;
- import java.nio.ByteBuffer;
- import java.security.MessageDigest;
- import java.security.NoSuchAlgorithmException;
-
- import org.eclipse.jgit.lib.Constants;
- import org.eclipse.jgit.lib.ObjectId;
- import org.eclipse.jgit.util.IO;
- import org.junit.Test;
-
- public class SHA1Test {
- private static final String TEST1 = "abc";
-
- private static final String TEST2a = "abcdbcdecdefdefgefghfghighijhi";
- private static final String TEST2b = "jkijkljklmklmnlmnomnopnopq";
- private static final String TEST2 = TEST2a + TEST2b;
-
- @Test
- public void test0() throws NoSuchAlgorithmException {
- ObjectId exp = ObjectId
- .fromString("da39a3ee5e6b4b0d3255bfef95601890afd80709");
-
- MessageDigest m = MessageDigest.getInstance("SHA-1");
- m.update(new byte[] {});
- ObjectId m1 = ObjectId.fromRaw(m.digest());
-
- SHA1 s = SHA1.newInstance();
- s.update(new byte[] {});
- ObjectId s1 = ObjectId.fromRaw(s.digest());
-
- s.reset();
- s.update(new byte[] {});
- ObjectId s2 = s.toObjectId();
-
- assertEquals(m1, s1);
- assertEquals(exp, s1);
- assertEquals(exp, s2);
- }
-
- @Test
- public void test1() throws NoSuchAlgorithmException {
- ObjectId exp = ObjectId
- .fromString("a9993e364706816aba3e25717850c26c9cd0d89d");
-
- MessageDigest m = MessageDigest.getInstance("SHA-1");
- m.update(TEST1.getBytes(UTF_8));
- ObjectId m1 = ObjectId.fromRaw(m.digest());
-
- SHA1 s = SHA1.newInstance();
- s.update(TEST1.getBytes(UTF_8));
- ObjectId s1 = ObjectId.fromRaw(s.digest());
-
- s.reset();
- s.update(TEST1.getBytes(UTF_8));
- ObjectId s2 = s.toObjectId();
-
- assertEquals(m1, s1);
- assertEquals(exp, s1);
- assertEquals(exp, s2);
- }
-
- @Test
- public void test2() throws NoSuchAlgorithmException {
- ObjectId exp = ObjectId
- .fromString("84983e441c3bd26ebaae4aa1f95129e5e54670f1");
-
- MessageDigest m = MessageDigest.getInstance("SHA-1");
- m.update(TEST2.getBytes(UTF_8));
- ObjectId m1 = ObjectId.fromRaw(m.digest());
-
- SHA1 s = SHA1.newInstance();
- s.update(TEST2.getBytes(UTF_8));
- ObjectId s1 = ObjectId.fromRaw(s.digest());
-
- s.reset();
- s.update(TEST2.getBytes(UTF_8));
- ObjectId s2 = s.toObjectId();
-
- assertEquals(m1, s1);
- assertEquals(exp, s1);
- assertEquals(exp, s2);
- }
-
- @Test
- public void shatteredCollision()
- throws IOException, NoSuchAlgorithmException {
- byte[] pdf1 = read("shattered-1.pdf", 422435);
- byte[] pdf2 = read("shattered-2.pdf", 422435);
- MessageDigest md;
- SHA1 s;
-
- // SHAttered attack generated these PDFs to have identical SHA-1.
- ObjectId bad = ObjectId
- .fromString("38762cf7f55934b34d179ae6a4c80cadccbb7f0a");
- md = MessageDigest.getInstance("SHA-1");
- md.update(pdf1);
- assertEquals("shattered-1 collides", bad,
- ObjectId.fromRaw(md.digest()));
- s = SHA1.newInstance().setDetectCollision(false);
- s.update(pdf1);
- assertEquals("shattered-1 collides", bad, s.toObjectId());
-
- md = MessageDigest.getInstance("SHA-1");
- md.update(pdf2);
- assertEquals("shattered-2 collides", bad,
- ObjectId.fromRaw(md.digest()));
- s = SHA1.newInstance().setDetectCollision(false);
- s.update(pdf2);
- assertEquals("shattered-2 collides", bad, s.toObjectId());
-
- // SHA1 with detectCollision shouldn't be fooled.
- s = SHA1.newInstance().setDetectCollision(true);
- s.update(pdf1);
- try {
- s.digest();
- fail("expected " + Sha1CollisionException.class.getSimpleName());
- } catch (Sha1CollisionException e) {
- assertEquals(e.getMessage(),
- "SHA-1 collision detected on " + bad.name());
- }
-
- s = SHA1.newInstance().setDetectCollision(true);
- s.update(pdf2);
- try {
- s.digest();
- fail("expected " + Sha1CollisionException.class.getSimpleName());
- } catch (Sha1CollisionException e) {
- assertEquals(e.getMessage(),
- "SHA-1 collision detected on " + bad.name());
- }
- }
-
- @Test
- public void shatteredStoredInGitBlob() throws IOException {
- byte[] pdf1 = read("shattered-1.pdf", 422435);
- byte[] pdf2 = read("shattered-2.pdf", 422435);
-
- // Although the prior test detects the chance of a collision, adding
- // the Git blob header permutes the data enough for this specific
- // attack example to not be detected as a collision. (A different file
- // pair that takes the Git header into account however, would.)
- ObjectId id1 = blob(pdf1, SHA1.newInstance().setDetectCollision(true));
- ObjectId id2 = blob(pdf2, SHA1.newInstance().setDetectCollision(true));
-
- assertEquals(
- ObjectId.fromString("ba9aaa145ccd24ef760cf31c74d8f7ca1a2e47b0"),
- id1);
- assertEquals(
- ObjectId.fromString("b621eeccd5c7edac9b7dcba35a8d5afd075e24f2"),
- id2);
- }
-
- @Test
- public void detectsShatteredByDefault() throws IOException {
- assumeTrue(System.getProperty("org.eclipse.jgit.util.sha1.detectCollision") == null);
- assumeTrue(System.getProperty("org.eclipse.jgit.util.sha1.safeHash") == null);
-
- byte[] pdf1 = read("shattered-1.pdf", 422435);
- SHA1 s = SHA1.newInstance();
- s.update(pdf1);
- try {
- s.digest();
- fail("expected " + Sha1CollisionException.class.getSimpleName());
- } catch (Sha1CollisionException e) {
- assertTrue("shattered-1 detected", true);
- }
- }
-
- private static ObjectId blob(byte[] pdf1, SHA1 s) {
- s.update(Constants.encodedTypeString(Constants.OBJ_BLOB));
- s.update((byte) ' ');
- s.update(Constants.encodeASCII(pdf1.length));
- s.update((byte) 0);
- s.update(pdf1);
- return s.toObjectId();
- }
-
- private byte[] read(String name, int sizeHint) throws IOException {
- try (InputStream in = getClass().getResourceAsStream(name)) {
- ByteBuffer buf = IO.readWholeStream(in, sizeHint);
- byte[] r = new byte[buf.remaining()];
- buf.get(r);
- return r;
- }
- }
- }
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