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Diffstat (limited to 'org.eclipse.jgit.test/tst/org/eclipse/jgit/util/sha1/SHA1Test.java')
-rw-r--r-- | org.eclipse.jgit.test/tst/org/eclipse/jgit/util/sha1/SHA1Test.java | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/util/sha1/SHA1Test.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/util/sha1/SHA1Test.java new file mode 100644 index 0000000000..07789898a4 --- /dev/null +++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/util/sha1/SHA1Test.java @@ -0,0 +1,238 @@ +/* + * 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 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.nio.charset.StandardCharsets; +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(StandardCharsets.UTF_8)); + ObjectId m1 = ObjectId.fromRaw(m.digest()); + + SHA1 s = SHA1.newInstance(); + s.update(TEST1.getBytes(StandardCharsets.UTF_8)); + ObjectId s1 = ObjectId.fromRaw(s.digest()); + + s.reset(); + s.update(TEST1.getBytes(StandardCharsets.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(StandardCharsets.UTF_8)); + ObjectId m1 = ObjectId.fromRaw(m.digest()); + + SHA1 s = SHA1.newInstance(); + s.update(TEST2.getBytes(StandardCharsets.UTF_8)); + ObjectId s1 = ObjectId.fromRaw(s.digest()); + + s.reset(); + s.update(TEST2.getBytes(StandardCharsets.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; + } + } +} |