Merge branch 'stable-5.13' into stable-6.0
* stable-5.13:
[benchmarks] Remove profiler configuration
Add SHA1 benchmark
[benchmarks] Set version of maven-compiler-plugin to 3.8.1
Fix running JMH benchmarks
Add option to allow using JDK's SHA1 implementation
Ignore IllegalStateException if JVM is already shutting down
Change-Id: I40105336f0b9e593a8a2c242a9557f854c274fdc
diff --git a/org.eclipse.jgit.benchmarks/pom.xml b/org.eclipse.jgit.benchmarks/pom.xml
index 8b16d18..55c80c6 100644
--- a/org.eclipse.jgit.benchmarks/pom.xml
+++ b/org.eclipse.jgit.benchmarks/pom.xml
@@ -37,13 +37,17 @@
<groupId>org.openjdk.jmh</groupId>
<artifactId>jmh-generator-annprocess</artifactId>
<version>${jmh.version}</version>
- <scope>provided</scope>
</dependency>
<dependency>
<groupId>org.eclipse.jgit</groupId>
<artifactId>org.eclipse.jgit</artifactId>
<version>${project.version}</version>
</dependency>
+ <dependency>
+ <groupId>org.eclipse.jgit</groupId>
+ <artifactId>org.eclipse.jgit.junit</artifactId>
+ <version>${project.version}</version>
+ </dependency>
</dependencies>
<build>
diff --git a/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/CreateFileSnapshotBenchmark.java b/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/CreateFileSnapshotBenchmark.java
index 97c847b..913ca5a 100644
--- a/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/CreateFileSnapshotBenchmark.java
+++ b/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/CreateFileSnapshotBenchmark.java
@@ -69,8 +69,6 @@ public FileSnapshot testCreateFileSnapshot() {
public static void main(String[] args) throws RunnerException {
Options opt = new OptionsBuilder()
.include(CreateFileSnapshotBenchmark.class.getSimpleName())
- // .addProfiler(StackProfiler.class)
- // .addProfiler(GCProfiler.class)
.forks(1).jvmArgs("-ea").build();
new Runner(opt).run();
}
diff --git a/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/FileMoveBenchmark.java b/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/FileMoveBenchmark.java
index d3ada22..2ec5f1f 100644
--- a/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/FileMoveBenchmark.java
+++ b/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/FileMoveBenchmark.java
@@ -128,8 +128,6 @@ public static void main(String[] args) throws RunnerException {
Options opt = new OptionsBuilder()
.include(FileMoveBenchmark.class
.getSimpleName())
- // .addProfiler(StackProfiler.class)
- // .addProfiler(GCProfiler.class)
.forks(1).jvmArgs("-ea").build();
new Runner(opt).run();
}
diff --git a/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/LookupFileStoreBenchmark.java b/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/LookupFileStoreBenchmark.java
index 858e2dc..393edcb 100644
--- a/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/LookupFileStoreBenchmark.java
+++ b/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/LookupFileStoreBenchmark.java
@@ -56,8 +56,6 @@ public FileStore testLookupFileStore() throws IOException {
public static void main(String[] args) throws RunnerException {
Options opt = new OptionsBuilder()
.include(LookupFileStoreBenchmark.class.getSimpleName())
- .addProfiler(StackProfiler.class)
- // .addProfiler(GCProfiler.class)
.forks(1).jvmArgs("-ea").build();
new Runner(opt).run();
}
diff --git a/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/SHA1Benchmark.java b/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/SHA1Benchmark.java
new file mode 100644
index 0000000..a2b5933
--- /dev/null
+++ b/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/SHA1Benchmark.java
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2022, Matthias Sohn <matthias.sohn@sap.com> and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0 which is available at
+ * https://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+package org.eclipse.jgit.benchmarks;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.concurrent.TimeUnit;
+
+import org.eclipse.jgit.junit.MockSystemReader;
+import org.eclipse.jgit.util.SystemReader;
+import org.eclipse.jgit.util.sha1.SHA1;
+import org.eclipse.jgit.util.sha1.SHA1.Sha1Implementation;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.TearDown;
+import org.openjdk.jmh.annotations.Warmup;
+import org.openjdk.jmh.infra.Blackhole;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.RunnerException;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+@State(Scope.Thread)
+public class SHA1Benchmark {
+
+ @State(Scope.Benchmark)
+ public static class BenchmarkState {
+
+ @Param({ "1", "2", "4", "8", "16", "32", "64" })
+ int size;
+
+ @Param({ "false", "true" })
+ boolean detectCollision;
+
+ @Param({ "java", "jdkNative" })
+ String impl;
+
+ private SecureRandom rnd;
+
+ byte[] content;
+
+ @Setup
+ public void setupBenchmark() {
+ SystemReader.setInstance(new MockSystemReader());
+ if (impl.equalsIgnoreCase(Sha1Implementation.JDKNATIVE.name())) {
+ System.setProperty("org.eclipse.jgit.util.sha1.implementation",
+ Sha1Implementation.JDKNATIVE.name());
+ }
+ content = new byte[size * 1024];
+ try {
+ rnd = SecureRandom.getInstanceStrong();
+ } catch (NoSuchAlgorithmException e) {
+ // ignore
+ }
+ rnd.nextBytes(content);
+ }
+
+ @TearDown
+ public void teardown() {
+ SystemReader.setInstance(null);
+ rnd = null;
+ }
+ }
+
+ @Benchmark
+ @BenchmarkMode({ Mode.AverageTime })
+ @OutputTimeUnit(TimeUnit.MICROSECONDS)
+ @Warmup(iterations = 2, time = 100, timeUnit = TimeUnit.MILLISECONDS)
+ @Measurement(iterations = 2, time = 5, timeUnit = TimeUnit.SECONDS)
+ @Fork(1)
+ public void testSHA1(Blackhole blackhole, BenchmarkState state) {
+ SHA1 hash = SHA1.newInstance();
+ hash.setDetectCollision(state.detectCollision);
+ hash.update(state.content);
+ blackhole.consume(hash.digest());
+ }
+
+ public static void main(String[] args) throws RunnerException {
+ Options opt = new OptionsBuilder()
+ .include(SHA1Benchmark.class.getSimpleName())
+ .forks(1).jvmArgs("-ea").build();
+ new Runner(opt).run();
+ }
+}
diff --git a/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/SimpleLruCacheBenchmark.java b/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/SimpleLruCacheBenchmark.java
index 73cc1c2..caefd75 100644
--- a/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/SimpleLruCacheBenchmark.java
+++ b/org.eclipse.jgit.benchmarks/src/org/eclipse/jgit/benchmarks/SimpleLruCacheBenchmark.java
@@ -71,8 +71,6 @@ public SimpleLruCache<String, String> testCacheRead() {
public static void main(String[] args) throws RunnerException {
Options opt = new OptionsBuilder()
.include(SimpleLruCacheBenchmark.class.getSimpleName())
- // .addProfiler(StackProfiler.class)
- // .addProfiler(GCProfiler.class)
.forks(1).jvmArgs("-ea").build();
new Runner(opt).run();
}
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
index ad560c2..abc2854 100644
--- 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
@@ -14,6 +14,7 @@
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
+import static org.junit.Assume.assumeFalse;
import static org.junit.Assume.assumeTrue;
import java.io.IOException;
@@ -22,11 +23,20 @@
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
+import org.eclipse.jgit.junit.MockSystemReader;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.util.IO;
-import org.junit.Test;
+import org.eclipse.jgit.util.SystemReader;
+import org.eclipse.jgit.util.sha1.SHA1.Sha1Implementation;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.experimental.theories.DataPoints;
+import org.junit.experimental.theories.Theories;
+import org.junit.experimental.theories.Theory;
+import org.junit.runner.RunWith;
+@RunWith(Theories.class)
public class SHA1Test {
private static final String TEST1 = "abc";
@@ -34,7 +44,32 @@ public class SHA1Test {
private static final String TEST2b = "jkijkljklmklmnlmnomnopnopq";
private static final String TEST2 = TEST2a + TEST2b;
- @Test
+ @DataPoints
+ public static Sha1Implementation[] getDataPoints() {
+ return new Sha1Implementation[] { Sha1Implementation.JAVA,
+ Sha1Implementation.JDKNATIVE };
+ }
+
+ private Sha1Implementation sha1Implementation;
+
+ public SHA1Test(Sha1Implementation impl) {
+ this.sha1Implementation = impl;
+ }
+
+ @Before
+ public void setUp() throws Exception {
+ MockSystemReader mockSystemReader = new MockSystemReader();
+ SystemReader.setInstance(mockSystemReader);
+ System.setProperty("org.eclipse.jgit.util.sha1.implementation",
+ sha1Implementation.name());
+ }
+
+ @After
+ public void tearDown() {
+ SystemReader.setInstance(null);
+ }
+
+ @Theory
public void test0() throws NoSuchAlgorithmException {
ObjectId exp = ObjectId
.fromString("da39a3ee5e6b4b0d3255bfef95601890afd80709");
@@ -56,7 +91,7 @@ public void test0() throws NoSuchAlgorithmException {
assertEquals(exp, s2);
}
- @Test
+ @Theory
public void test1() throws NoSuchAlgorithmException {
ObjectId exp = ObjectId
.fromString("a9993e364706816aba3e25717850c26c9cd0d89d");
@@ -78,7 +113,7 @@ public void test1() throws NoSuchAlgorithmException {
assertEquals(exp, s2);
}
- @Test
+ @Theory
public void test2() throws NoSuchAlgorithmException {
ObjectId exp = ObjectId
.fromString("84983e441c3bd26ebaae4aa1f95129e5e54670f1");
@@ -100,9 +135,13 @@ public void test2() throws NoSuchAlgorithmException {
assertEquals(exp, s2);
}
- @Test
+ @Theory
public void shatteredCollision()
throws IOException, NoSuchAlgorithmException {
+ assumeFalse(
+ System.getProperty("org.eclipse.jgit.util.sha1.implementation")
+ .equalsIgnoreCase("jdkNative"));
+
byte[] pdf1 = read("shattered-1.pdf", 422435);
byte[] pdf2 = read("shattered-2.pdf", 422435);
MessageDigest md;
@@ -149,8 +188,12 @@ public void shatteredCollision()
}
}
- @Test
+ @Theory
public void shatteredStoredInGitBlob() throws IOException {
+ assumeFalse(
+ System.getProperty("org.eclipse.jgit.util.sha1.implementation")
+ .equalsIgnoreCase("jdkNative"));
+
byte[] pdf1 = read("shattered-1.pdf", 422435);
byte[] pdf2 = read("shattered-2.pdf", 422435);
@@ -158,8 +201,10 @@ public void shatteredStoredInGitBlob() throws IOException {
// 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));
+ ObjectId id1 = blob(pdf1,
+ SHA1.newInstance().setDetectCollision(true));
+ ObjectId id2 = blob(pdf2,
+ SHA1.newInstance().setDetectCollision(true));
assertEquals(
ObjectId.fromString("ba9aaa145ccd24ef760cf31c74d8f7ca1a2e47b0"),
@@ -169,8 +214,12 @@ public void shatteredStoredInGitBlob() throws IOException {
id2);
}
- @Test
+ @Theory
public void detectsShatteredByDefault() throws IOException {
+ assumeFalse(
+ System.getProperty("org.eclipse.jgit.util.sha1.implementation")
+ .equalsIgnoreCase("jdkNative"));
+
assumeTrue(System.getProperty("org.eclipse.jgit.util.sha1.detectCollision") == null);
assumeTrue(System.getProperty("org.eclipse.jgit.util.sha1.safeHash") == null);
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java
index 24eebc6..924328d 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ConfigConstants.java
@@ -438,6 +438,13 @@ public final class ConfigConstants {
public static final String CONFIG_KEY_SUPPORTSATOMICFILECREATION = "supportsatomicfilecreation";
/**
+ * The "sha1Implementation" key in the "core" section
+ *
+ * @since 5.13.2
+ */
+ public static final String SHA1_IMPLEMENTATION = "sha1implementation";
+
+ /**
* The "noprefix" key in the "diff" section
* @since 3.0
*/
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java
index e8f38d8..aef9e64 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java
@@ -299,14 +299,19 @@ public static final class FileStoreAttributes {
static {
// Shut down the SAVE_RUNNER on System.exit()
- Runtime.getRuntime().addShutdownHook(new Thread(() -> {
- try {
- SAVE_RUNNER.shutdownNow();
- SAVE_RUNNER.awaitTermination(100, TimeUnit.MILLISECONDS);
- } catch (Exception e) {
- // Ignore; we're shutting down
- }
- }));
+ try {
+ Runtime.getRuntime().addShutdownHook(new Thread(() -> {
+ try {
+ SAVE_RUNNER.shutdownNow();
+ SAVE_RUNNER.awaitTermination(100,
+ TimeUnit.MILLISECONDS);
+ } catch (Exception e) {
+ // Ignore; we're shutting down
+ }
+ }));
+ } catch (IllegalStateException e) {
+ // ignore - may fail if shutdown is already in progress
+ }
}
/**
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1.java
index 1420add..87993d2 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1.java
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2017, Google Inc. and others
+ * Copyright (C) 2022, Matthias Sohn <matthias.sohn@sap.com> and others
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0 which is available at
@@ -7,99 +7,96 @@
*
* SPDX-License-Identifier: BSD-3-Clause
*/
-
package org.eclipse.jgit.util.sha1;
-import static java.lang.Integer.lowestOneBit;
-import static java.lang.Integer.numberOfTrailingZeros;
-import static java.lang.Integer.rotateLeft;
-import static java.lang.Integer.rotateRight;
+import java.io.IOException;
+import java.security.MessageDigest;
-import java.text.MessageFormat;
-import java.util.Arrays;
-
-import org.eclipse.jgit.internal.JGitText;
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.lib.ConfigConstants;
import org.eclipse.jgit.lib.MutableObjectId;
import org.eclipse.jgit.lib.ObjectId;
-import org.eclipse.jgit.util.NB;
import org.eclipse.jgit.util.SystemReader;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
/**
- * Pure Java implementation of SHA-1 from FIPS 180-1 / RFC 3174.
- *
+ * SHA-1 interface from FIPS 180-1 / RFC 3174 with optional collision detection.
+ * Some implementations may not support collision detection.
* <p>
* See <a href="https://tools.ietf.org/html/rfc3174">RFC 3174</a>.
- * <p>
- * Unlike MessageDigest, this implementation includes the algorithm used by
- * {@code sha1dc} to detect cryptanalytic collision attacks against SHA-1, such
- * as the one used by <a href="https://shattered.it/">SHAttered</a>. See
- * <a href="https://github.com/cr-marcstevens/sha1collisiondetection">
- * sha1collisiondetection</a> for more information.
- * <p>
- * When detectCollision is true (default), this implementation throws
- * {@link org.eclipse.jgit.util.sha1.Sha1CollisionException} from any digest
- * method if a potential collision was detected.
- *
- * @since 4.7
*/
-public class SHA1 {
- private static final Logger LOG = LoggerFactory.getLogger(SHA1.class);
- private static final boolean DETECT_COLLISIONS;
+public abstract class SHA1 {
+ /**
+ * SHA1 implementations available in JGit
+ */
+ public enum Sha1Implementation {
+ /**
+ * {@link SHA1Java} implemented in Java, supports collision detection.
+ */
+ JAVA(SHA1Java.class),
+ /**
+ * Native implementation based on JDK's {@link MessageDigest}.
+ */
+ JDKNATIVE(SHA1Native.class);
- static {
- SystemReader sr = SystemReader.getInstance();
- String v = sr.getProperty("org.eclipse.jgit.util.sha1.detectCollision"); //$NON-NLS-1$
- DETECT_COLLISIONS = v != null ? Boolean.parseBoolean(v) : true;
+ private final String implClassName;
+
+ private Sha1Implementation(Class implClass) {
+ this.implClassName = implClass.getName();
+ }
+
+ @Override
+ public String toString() {
+ return implClassName;
+ }
+ }
+
+ private static final Sha1Implementation SHA1_IMPLEMENTATION = fromConfig();
+
+ private static Sha1Implementation fromConfig() {
+ try {
+ return SystemReader.getInstance().getUserConfig().getEnum(
+ ConfigConstants.CONFIG_CORE_SECTION, null,
+ ConfigConstants.SHA1_IMPLEMENTATION,
+ Sha1Implementation.JAVA);
+ } catch (ConfigInvalidException | IOException e) {
+ return Sha1Implementation.JAVA;
+ }
+ }
+
+ private static Sha1Implementation getImplementation() {
+ String fromSystemProperty = System
+ .getProperty("org.eclipse.jgit.util.sha1.implementation"); //$NON-NLS-1$
+ if (fromSystemProperty == null) {
+ return SHA1_IMPLEMENTATION;
+ }
+ if (fromSystemProperty
+ .equalsIgnoreCase(Sha1Implementation.JAVA.name())) {
+ return Sha1Implementation.JAVA;
+ }
+ if (fromSystemProperty
+ .equalsIgnoreCase(Sha1Implementation.JDKNATIVE.name())) {
+ return Sha1Implementation.JDKNATIVE;
+ }
+ return SHA1_IMPLEMENTATION;
}
/**
* Create a new context to compute a SHA-1 hash of data.
+ * <p>
+ * If {@code core.sha1Implementation = jdkNative} in the user level global
+ * git configuration or the system property
+ * {@code org.eclipse.jgit.util.sha1.implementation = jdkNative} it will
+ * create an object using the implementation in the JDK. If both are set the
+ * system property takes precedence. Otherwise the pure Java implementation
+ * will be used which supports collision detection but is slower.
*
* @return a new context to compute a SHA-1 hash of data.
*/
public static SHA1 newInstance() {
- return new SHA1();
- }
-
- private final State h = new State();
- private final int[] w = new int[80];
-
- /** Buffer to accumulate partial blocks to 64 byte alignment. */
- private final byte[] buffer = new byte[64];
-
- /** Total number of bytes in the message. */
- private long length;
-
- private boolean detectCollision = DETECT_COLLISIONS;
- private boolean foundCollision;
-
- private final int[] w2 = new int[80];
- private final State state58 = new State();
- private final State state65 = new State();
- private final State hIn = new State();
- private final State hTmp = new State();
-
- private SHA1() {
- h.init();
- }
-
- /**
- * Enable likely collision detection.
- * <p>
- * Default is {@code true}.
- * <p>
- * May also be set by system property:
- * {@code -Dorg.eclipse.jgit.util.sha1.detectCollision=true}.
- *
- * @param detect
- * a boolean.
- * @return {@code this}
- */
- public SHA1 setDetectCollision(boolean detect) {
- detectCollision = detect;
- return this;
+ if (getImplementation() == Sha1Implementation.JDKNATIVE) {
+ return new SHA1Native();
+ }
+ return new SHA1Java();
}
/**
@@ -107,14 +104,7 @@ public SHA1 setDetectCollision(boolean detect) {
*
* @param b a byte.
*/
- public void update(byte b) {
- int bufferLen = (int) (length & 63);
- length++;
- buffer[bufferLen] = b;
- if (bufferLen == 63) {
- compress(buffer, 0);
- }
- }
+ public abstract void update(byte b);
/**
* Update the digest computation by adding bytes to the message.
@@ -122,9 +112,7 @@ public void update(byte b) {
* @param in
* input array of bytes.
*/
- public void update(byte[] in) {
- update(in, 0, in.length);
- }
+ public abstract void update(byte[] in);
/**
* Update the digest computation by adding bytes to the message.
@@ -136,344 +124,7 @@ public void update(byte[] in) {
* @param len
* number of bytes to hash.
*/
- public void update(byte[] in, int p, int len) {
- // SHA-1 compress can only process whole 64 byte blocks.
- // Hold partial updates in buffer, whose length is the low bits.
- int bufferLen = (int) (length & 63);
- length += len;
-
- if (bufferLen > 0) {
- int n = Math.min(64 - bufferLen, len);
- System.arraycopy(in, p, buffer, bufferLen, n);
- p += n;
- len -= n;
- if (bufferLen + n < 64) {
- return;
- }
- compress(buffer, 0);
- }
- while (len >= 64) {
- compress(in, p);
- p += 64;
- len -= 64;
- }
- if (len > 0) {
- System.arraycopy(in, p, buffer, 0, len);
- }
- }
-
- private void compress(byte[] block, int p) {
- initBlock(block, p);
- int ubcDvMask = detectCollision ? UbcCheck.check(w) : 0;
- compress();
-
- while (ubcDvMask != 0) {
- int b = numberOfTrailingZeros(lowestOneBit(ubcDvMask));
- UbcCheck.DvInfo dv = UbcCheck.DV[b];
- for (int i = 0; i < 80; i++) {
- w2[i] = w[i] ^ dv.dm[i];
- }
- recompress(dv.testt);
- if (eq(hTmp, h)) {
- foundCollision = true;
- break;
- }
- ubcDvMask &= ~(1 << b);
- }
- }
-
- private void initBlock(byte[] block, int p) {
- for (int t = 0; t < 16; t++) {
- w[t] = NB.decodeInt32(block, p + (t << 2));
- }
-
- // RFC 3174 6.1.b, extend state vector to 80 words.
- for (int t = 16; t < 80; t++) {
- int x = w[t - 3] ^ w[t - 8] ^ w[t - 14] ^ w[t - 16];
- w[t] = rotateLeft(x, 1); // S^1(...)
- }
- }
-
- private void compress() {
- // Method 1 from RFC 3174 section 6.1.
- // Method 2 (circular queue of 16 words) is slower.
- int a = h.a, b = h.b, c = h.c, d = h.d, e = h.e;
-
- // @formatter:off
- e += s1(a, b, c, d,w[ 0]); b = rotateLeft( b, 30);
- d += s1(e, a, b, c,w[ 1]); a = rotateLeft( a, 30);
- c += s1(d, e, a, b,w[ 2]); e = rotateLeft( e, 30);
- b += s1(c, d, e, a,w[ 3]); d = rotateLeft( d, 30);
- a += s1(b, c, d, e,w[ 4]); c = rotateLeft( c, 30);
- e += s1(a, b, c, d,w[ 5]); b = rotateLeft( b, 30);
- d += s1(e, a, b, c,w[ 6]); a = rotateLeft( a, 30);
- c += s1(d, e, a, b,w[ 7]); e = rotateLeft( e, 30);
- b += s1(c, d, e, a,w[ 8]); d = rotateLeft( d, 30);
- a += s1(b, c, d, e,w[ 9]); c = rotateLeft( c, 30);
- e += s1(a, b, c, d,w[ 10]); b = rotateLeft( b, 30);
- d += s1(e, a, b, c,w[ 11]); a = rotateLeft( a, 30);
- c += s1(d, e, a, b,w[ 12]); e = rotateLeft( e, 30);
- b += s1(c, d, e, a,w[ 13]); d = rotateLeft( d, 30);
- a += s1(b, c, d, e,w[ 14]); c = rotateLeft( c, 30);
- e += s1(a, b, c, d,w[ 15]); b = rotateLeft( b, 30);
- d += s1(e, a, b, c,w[ 16]); a = rotateLeft( a, 30);
- c += s1(d, e, a, b,w[ 17]); e = rotateLeft( e, 30);
- b += s1(c, d, e, a,w[ 18]); d = rotateLeft( d, 30);
- a += s1(b, c, d, e,w[ 19]); c = rotateLeft( c, 30);
-
- e += s2(a, b, c, d,w[ 20]); b = rotateLeft( b, 30);
- d += s2(e, a, b, c,w[ 21]); a = rotateLeft( a, 30);
- c += s2(d, e, a, b,w[ 22]); e = rotateLeft( e, 30);
- b += s2(c, d, e, a,w[ 23]); d = rotateLeft( d, 30);
- a += s2(b, c, d, e,w[ 24]); c = rotateLeft( c, 30);
- e += s2(a, b, c, d,w[ 25]); b = rotateLeft( b, 30);
- d += s2(e, a, b, c,w[ 26]); a = rotateLeft( a, 30);
- c += s2(d, e, a, b,w[ 27]); e = rotateLeft( e, 30);
- b += s2(c, d, e, a,w[ 28]); d = rotateLeft( d, 30);
- a += s2(b, c, d, e,w[ 29]); c = rotateLeft( c, 30);
- e += s2(a, b, c, d,w[ 30]); b = rotateLeft( b, 30);
- d += s2(e, a, b, c,w[ 31]); a = rotateLeft( a, 30);
- c += s2(d, e, a, b,w[ 32]); e = rotateLeft( e, 30);
- b += s2(c, d, e, a,w[ 33]); d = rotateLeft( d, 30);
- a += s2(b, c, d, e,w[ 34]); c = rotateLeft( c, 30);
- e += s2(a, b, c, d,w[ 35]); b = rotateLeft( b, 30);
- d += s2(e, a, b, c,w[ 36]); a = rotateLeft( a, 30);
- c += s2(d, e, a, b,w[ 37]); e = rotateLeft( e, 30);
- b += s2(c, d, e, a,w[ 38]); d = rotateLeft( d, 30);
- a += s2(b, c, d, e,w[ 39]); c = rotateLeft( c, 30);
-
- e += s3(a, b, c, d,w[ 40]); b = rotateLeft( b, 30);
- d += s3(e, a, b, c,w[ 41]); a = rotateLeft( a, 30);
- c += s3(d, e, a, b,w[ 42]); e = rotateLeft( e, 30);
- b += s3(c, d, e, a,w[ 43]); d = rotateLeft( d, 30);
- a += s3(b, c, d, e,w[ 44]); c = rotateLeft( c, 30);
- e += s3(a, b, c, d,w[ 45]); b = rotateLeft( b, 30);
- d += s3(e, a, b, c,w[ 46]); a = rotateLeft( a, 30);
- c += s3(d, e, a, b,w[ 47]); e = rotateLeft( e, 30);
- b += s3(c, d, e, a,w[ 48]); d = rotateLeft( d, 30);
- a += s3(b, c, d, e,w[ 49]); c = rotateLeft( c, 30);
- e += s3(a, b, c, d,w[ 50]); b = rotateLeft( b, 30);
- d += s3(e, a, b, c,w[ 51]); a = rotateLeft( a, 30);
- c += s3(d, e, a, b,w[ 52]); e = rotateLeft( e, 30);
- b += s3(c, d, e, a,w[ 53]); d = rotateLeft( d, 30);
- a += s3(b, c, d, e,w[ 54]); c = rotateLeft( c, 30);
- e += s3(a, b, c, d,w[ 55]); b = rotateLeft( b, 30);
- d += s3(e, a, b, c,w[ 56]); a = rotateLeft( a, 30);
- c += s3(d, e, a, b,w[ 57]); e = rotateLeft( e, 30);
- state58.save(a, b, c, d, e);
- b += s3(c, d, e, a,w[ 58]); d = rotateLeft( d, 30);
- a += s3(b, c, d, e,w[ 59]); c = rotateLeft( c, 30);
-
- e += s4(a, b, c, d,w[ 60]); b = rotateLeft( b, 30);
- d += s4(e, a, b, c,w[ 61]); a = rotateLeft( a, 30);
- c += s4(d, e, a, b,w[ 62]); e = rotateLeft( e, 30);
- b += s4(c, d, e, a,w[ 63]); d = rotateLeft( d, 30);
- a += s4(b, c, d, e,w[ 64]); c = rotateLeft( c, 30);
- state65.save(a, b, c, d, e);
- e += s4(a, b, c, d,w[ 65]); b = rotateLeft( b, 30);
- d += s4(e, a, b, c,w[ 66]); a = rotateLeft( a, 30);
- c += s4(d, e, a, b,w[ 67]); e = rotateLeft( e, 30);
- b += s4(c, d, e, a,w[ 68]); d = rotateLeft( d, 30);
- a += s4(b, c, d, e,w[ 69]); c = rotateLeft( c, 30);
- e += s4(a, b, c, d,w[ 70]); b = rotateLeft( b, 30);
- d += s4(e, a, b, c,w[ 71]); a = rotateLeft( a, 30);
- c += s4(d, e, a, b,w[ 72]); e = rotateLeft( e, 30);
- b += s4(c, d, e, a,w[ 73]); d = rotateLeft( d, 30);
- a += s4(b, c, d, e,w[ 74]); c = rotateLeft( c, 30);
- e += s4(a, b, c, d,w[ 75]); b = rotateLeft( b, 30);
- d += s4(e, a, b, c,w[ 76]); a = rotateLeft( a, 30);
- c += s4(d, e, a, b,w[ 77]); e = rotateLeft( e, 30);
- b += s4(c, d, e, a,w[ 78]); d = rotateLeft( d, 30);
- a += s4(b, c, d, e,w[ 79]); c = rotateLeft( c, 30);
-
- // @formatter:on
- h.save(h.a + a, h.b + b, h.c + c, h.d + d, h.e + e);
- }
-
- private void recompress(int t) {
- State s;
- switch (t) {
- case 58:
- s = state58;
- break;
- case 65:
- s = state65;
- break;
- default:
- throw new IllegalStateException();
- }
- int a = s.a, b = s.b, c = s.c, d = s.d, e = s.e;
-
- // @formatter:off
- if (t == 65) {
- { c = rotateRight( c, 30); a -= s4(b, c, d, e,w2[ 64]);}
- { d = rotateRight( d, 30); b -= s4(c, d, e, a,w2[ 63]);}
- { e = rotateRight( e, 30); c -= s4(d, e, a, b,w2[ 62]);}
- { a = rotateRight( a, 30); d -= s4(e, a, b, c,w2[ 61]);}
- { b = rotateRight( b, 30); e -= s4(a, b, c, d,w2[ 60]);}
-
- { c = rotateRight( c, 30); a -= s3(b, c, d, e,w2[ 59]);}
- { d = rotateRight( d, 30); b -= s3(c, d, e, a,w2[ 58]);}
- }
- { e = rotateRight( e, 30); c -= s3(d, e, a, b,w2[ 57]);}
- { a = rotateRight( a, 30); d -= s3(e, a, b, c,w2[ 56]);}
- { b = rotateRight( b, 30); e -= s3(a, b, c, d,w2[ 55]);}
- { c = rotateRight( c, 30); a -= s3(b, c, d, e,w2[ 54]);}
- { d = rotateRight( d, 30); b -= s3(c, d, e, a,w2[ 53]);}
- { e = rotateRight( e, 30); c -= s3(d, e, a, b,w2[ 52]);}
- { a = rotateRight( a, 30); d -= s3(e, a, b, c,w2[ 51]);}
- { b = rotateRight( b, 30); e -= s3(a, b, c, d,w2[ 50]);}
- { c = rotateRight( c, 30); a -= s3(b, c, d, e,w2[ 49]);}
- { d = rotateRight( d, 30); b -= s3(c, d, e, a,w2[ 48]);}
- { e = rotateRight( e, 30); c -= s3(d, e, a, b,w2[ 47]);}
- { a = rotateRight( a, 30); d -= s3(e, a, b, c,w2[ 46]);}
- { b = rotateRight( b, 30); e -= s3(a, b, c, d,w2[ 45]);}
- { c = rotateRight( c, 30); a -= s3(b, c, d, e,w2[ 44]);}
- { d = rotateRight( d, 30); b -= s3(c, d, e, a,w2[ 43]);}
- { e = rotateRight( e, 30); c -= s3(d, e, a, b,w2[ 42]);}
- { a = rotateRight( a, 30); d -= s3(e, a, b, c,w2[ 41]);}
- { b = rotateRight( b, 30); e -= s3(a, b, c, d,w2[ 40]);}
-
- { c = rotateRight( c, 30); a -= s2(b, c, d, e,w2[ 39]);}
- { d = rotateRight( d, 30); b -= s2(c, d, e, a,w2[ 38]);}
- { e = rotateRight( e, 30); c -= s2(d, e, a, b,w2[ 37]);}
- { a = rotateRight( a, 30); d -= s2(e, a, b, c,w2[ 36]);}
- { b = rotateRight( b, 30); e -= s2(a, b, c, d,w2[ 35]);}
- { c = rotateRight( c, 30); a -= s2(b, c, d, e,w2[ 34]);}
- { d = rotateRight( d, 30); b -= s2(c, d, e, a,w2[ 33]);}
- { e = rotateRight( e, 30); c -= s2(d, e, a, b,w2[ 32]);}
- { a = rotateRight( a, 30); d -= s2(e, a, b, c,w2[ 31]);}
- { b = rotateRight( b, 30); e -= s2(a, b, c, d,w2[ 30]);}
- { c = rotateRight( c, 30); a -= s2(b, c, d, e,w2[ 29]);}
- { d = rotateRight( d, 30); b -= s2(c, d, e, a,w2[ 28]);}
- { e = rotateRight( e, 30); c -= s2(d, e, a, b,w2[ 27]);}
- { a = rotateRight( a, 30); d -= s2(e, a, b, c,w2[ 26]);}
- { b = rotateRight( b, 30); e -= s2(a, b, c, d,w2[ 25]);}
- { c = rotateRight( c, 30); a -= s2(b, c, d, e,w2[ 24]);}
- { d = rotateRight( d, 30); b -= s2(c, d, e, a,w2[ 23]);}
- { e = rotateRight( e, 30); c -= s2(d, e, a, b,w2[ 22]);}
- { a = rotateRight( a, 30); d -= s2(e, a, b, c,w2[ 21]);}
- { b = rotateRight( b, 30); e -= s2(a, b, c, d,w2[ 20]);}
-
- { c = rotateRight( c, 30); a -= s1(b, c, d, e,w2[ 19]);}
- { d = rotateRight( d, 30); b -= s1(c, d, e, a,w2[ 18]);}
- { e = rotateRight( e, 30); c -= s1(d, e, a, b,w2[ 17]);}
- { a = rotateRight( a, 30); d -= s1(e, a, b, c,w2[ 16]);}
- { b = rotateRight( b, 30); e -= s1(a, b, c, d,w2[ 15]);}
- { c = rotateRight( c, 30); a -= s1(b, c, d, e,w2[ 14]);}
- { d = rotateRight( d, 30); b -= s1(c, d, e, a,w2[ 13]);}
- { e = rotateRight( e, 30); c -= s1(d, e, a, b,w2[ 12]);}
- { a = rotateRight( a, 30); d -= s1(e, a, b, c,w2[ 11]);}
- { b = rotateRight( b, 30); e -= s1(a, b, c, d,w2[ 10]);}
- { c = rotateRight( c, 30); a -= s1(b, c, d, e,w2[ 9]);}
- { d = rotateRight( d, 30); b -= s1(c, d, e, a,w2[ 8]);}
- { e = rotateRight( e, 30); c -= s1(d, e, a, b,w2[ 7]);}
- { a = rotateRight( a, 30); d -= s1(e, a, b, c,w2[ 6]);}
- { b = rotateRight( b, 30); e -= s1(a, b, c, d,w2[ 5]);}
- { c = rotateRight( c, 30); a -= s1(b, c, d, e,w2[ 4]);}
- { d = rotateRight( d, 30); b -= s1(c, d, e, a,w2[ 3]);}
- { e = rotateRight( e, 30); c -= s1(d, e, a, b,w2[ 2]);}
- { a = rotateRight( a, 30); d -= s1(e, a, b, c,w2[ 1]);}
- { b = rotateRight( b, 30); e -= s1(a, b, c, d,w2[ 0]);}
-
- hIn.save(a, b, c, d, e);
- a = s.a; b = s.b; c = s.c; d = s.d; e = s.e;
-
- if (t == 58) {
- { b += s3(c, d, e, a,w2[ 58]); d = rotateLeft( d, 30);}
- { a += s3(b, c, d, e,w2[ 59]); c = rotateLeft( c, 30);}
-
- { e += s4(a, b, c, d,w2[ 60]); b = rotateLeft( b, 30);}
- { d += s4(e, a, b, c,w2[ 61]); a = rotateLeft( a, 30);}
- { c += s4(d, e, a, b,w2[ 62]); e = rotateLeft( e, 30);}
- { b += s4(c, d, e, a,w2[ 63]); d = rotateLeft( d, 30);}
- { a += s4(b, c, d, e,w2[ 64]); c = rotateLeft( c, 30);}
- }
- { e += s4(a, b, c, d,w2[ 65]); b = rotateLeft( b, 30);}
- { d += s4(e, a, b, c,w2[ 66]); a = rotateLeft( a, 30);}
- { c += s4(d, e, a, b,w2[ 67]); e = rotateLeft( e, 30);}
- { b += s4(c, d, e, a,w2[ 68]); d = rotateLeft( d, 30);}
- { a += s4(b, c, d, e,w2[ 69]); c = rotateLeft( c, 30);}
- { e += s4(a, b, c, d,w2[ 70]); b = rotateLeft( b, 30);}
- { d += s4(e, a, b, c,w2[ 71]); a = rotateLeft( a, 30);}
- { c += s4(d, e, a, b,w2[ 72]); e = rotateLeft( e, 30);}
- { b += s4(c, d, e, a,w2[ 73]); d = rotateLeft( d, 30);}
- { a += s4(b, c, d, e,w2[ 74]); c = rotateLeft( c, 30);}
- { e += s4(a, b, c, d,w2[ 75]); b = rotateLeft( b, 30);}
- { d += s4(e, a, b, c,w2[ 76]); a = rotateLeft( a, 30);}
- { c += s4(d, e, a, b,w2[ 77]); e = rotateLeft( e, 30);}
- { b += s4(c, d, e, a,w2[ 78]); d = rotateLeft( d, 30);}
- { a += s4(b, c, d, e,w2[ 79]); c = rotateLeft( c, 30);}
-
- // @formatter:on
- hTmp.save(hIn.a + a, hIn.b + b, hIn.c + c, hIn.d + d, hIn.e + e);
- }
-
- private static int s1(int a, int b, int c, int d, int w_t) {
- return rotateLeft(a, 5)
- // f: 0 <= t <= 19
- + ((b & c) | ((~b) & d))
- + 0x5A827999 + w_t;
- }
-
- private static int s2(int a, int b, int c, int d, int w_t) {
- return rotateLeft(a, 5)
- // f: 20 <= t <= 39
- + (b ^ c ^ d)
- + 0x6ED9EBA1 + w_t;
- }
-
- private static int s3(int a, int b, int c, int d, int w_t) {
- return rotateLeft(a, 5)
- // f: 40 <= t <= 59
- + ((b & c) | (b & d) | (c & d))
- + 0x8F1BBCDC + w_t;
- }
-
- private static int s4(int a, int b, int c, int d, int w_t) {
- return rotateLeft(a, 5)
- // f: 60 <= t <= 79
- + (b ^ c ^ d)
- + 0xCA62C1D6 + w_t;
- }
-
- private static boolean eq(State q, State r) {
- return q.a == r.a
- && q.b == r.b
- && q.c == r.c
- && q.d == r.d
- && q.e == r.e;
- }
-
- private void finish() {
- int bufferLen = (int) (length & 63);
- if (bufferLen > 55) {
- // Last block is too small; pad, compress, pad another block.
- buffer[bufferLen++] = (byte) 0x80;
- Arrays.fill(buffer, bufferLen, 64, (byte) 0);
- compress(buffer, 0);
- Arrays.fill(buffer, 0, 56, (byte) 0);
- } else {
- // Last block can hold padding and length.
- buffer[bufferLen++] = (byte) 0x80;
- Arrays.fill(buffer, bufferLen, 56, (byte) 0);
- }
-
- // SHA-1 appends the length of the message in bits after the
- // padding block (above). Here length is in bytes. Multiply by
- // 8 by shifting by 3 as part of storing the 64 bit byte length
- // into the two words expected in the trailer.
- NB.encodeInt32(buffer, 56, (int) (length >>> (32 - 3)));
- NB.encodeInt32(buffer, 60, (int) (length << 3));
- compress(buffer, 0);
-
- if (foundCollision) {
- ObjectId id = h.toObjectId();
- LOG.warn(MessageFormat.format(JGitText.get().sha1CollisionDetected,
- id.name()));
- throw new Sha1CollisionException(id);
- }
- }
+ public abstract void update(byte[] in, int p, int len);
/**
* Finish the digest and return the resulting hash.
@@ -484,17 +135,7 @@ private void finish() {
* @throws org.eclipse.jgit.util.sha1.Sha1CollisionException
* if a collision was detected and safeHash is false.
*/
- public byte[] digest() throws Sha1CollisionException {
- finish();
-
- byte[] b = new byte[20];
- NB.encodeInt32(b, 0, h.a);
- NB.encodeInt32(b, 4, h.b);
- NB.encodeInt32(b, 8, h.c);
- NB.encodeInt32(b, 12, h.d);
- NB.encodeInt32(b, 16, h.e);
- return b;
- }
+ public abstract byte[] digest() throws Sha1CollisionException;
/**
* Finish the digest and return the resulting hash.
@@ -505,10 +146,7 @@ private void finish() {
* @throws org.eclipse.jgit.util.sha1.Sha1CollisionException
* if a collision was detected and safeHash is false.
*/
- public ObjectId toObjectId() throws Sha1CollisionException {
- finish();
- return h.toObjectId();
- }
+ public abstract ObjectId toObjectId() throws Sha1CollisionException;
/**
* Finish the digest and return the resulting hash.
@@ -520,60 +158,42 @@ public ObjectId toObjectId() throws Sha1CollisionException {
* @throws org.eclipse.jgit.util.sha1.Sha1CollisionException
* if a collision was detected and safeHash is false.
*/
- public void digest(MutableObjectId id) throws Sha1CollisionException {
- finish();
- id.set(h.a, h.b, h.c, h.d, h.e);
- }
-
- /**
- * Check if a collision was detected.
- *
- * <p>
- * This method only returns an accurate result after the digest was obtained
- * through {@link #digest()}, {@link #digest(MutableObjectId)} or
- * {@link #toObjectId()}, as the hashing function must finish processing to
- * know the final state.
- *
- * @return {@code true} if a likely collision was detected.
- */
- public boolean hasCollision() {
- return foundCollision;
- }
+ public abstract void digest(MutableObjectId id)
+ throws Sha1CollisionException;
/**
* Reset this instance to compute another hash.
*
* @return {@code this}.
*/
- public SHA1 reset() {
- h.init();
- length = 0;
- foundCollision = false;
- return this;
- }
+ public abstract SHA1 reset();
- private static final class State {
- int a;
- int b;
- int c;
- int d;
- int e;
+ /**
+ * Enable likely collision detection.
+ * <p>
+ * Default for implementations supporting collision detection is
+ * {@code true}.
+ * <p>
+ * Implementations not supporting collision detection ignore calls to this
+ * method.
+ *
+ * @param detect
+ * a boolean.
+ * @return {@code this}
+ */
+ public abstract SHA1 setDetectCollision(boolean detect);
- final void init() {
- // Magic initialization constants defined by FIPS180.
- save(0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0);
- }
-
- final void save(int a1, int b1, int c1, int d1, int e1) {
- a = a1;
- b = b1;
- c = c1;
- d = d1;
- e = e1;
- }
-
- ObjectId toObjectId() {
- return new ObjectId(a, b, c, d, e);
- }
- }
-}
+ /**
+ * Check if a collision was detected. This method only returns an accurate
+ * result after the digest was obtained through {@link #digest()},
+ * {@link #digest(MutableObjectId)} or {@link #toObjectId()}, as the hashing
+ * function must finish processing to know the final state.
+ * <p>
+ * Implementations not supporting collision detection always return
+ * {@code false}.
+ * <p>
+ *
+ * @return {@code true} if a likely collision was detected.
+ */
+ public abstract boolean hasCollision();
+}
\ No newline at end of file
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1Java.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1Java.java
new file mode 100644
index 0000000..213ee97
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1Java.java
@@ -0,0 +1,579 @@
+/*
+ * Copyright (C) 2017, Google Inc. and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0 which is available at
+ * https://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+package org.eclipse.jgit.util.sha1;
+
+import static java.lang.Integer.lowestOneBit;
+import static java.lang.Integer.numberOfTrailingZeros;
+import static java.lang.Integer.rotateLeft;
+import static java.lang.Integer.rotateRight;
+
+import java.text.MessageFormat;
+import java.util.Arrays;
+
+import org.eclipse.jgit.internal.JGitText;
+import org.eclipse.jgit.lib.MutableObjectId;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.util.NB;
+import org.eclipse.jgit.util.SystemReader;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Pure Java implementation of SHA-1 from FIPS 180-1 / RFC 3174.
+ *
+ * <p>
+ * See <a href="https://tools.ietf.org/html/rfc3174">RFC 3174</a>.
+ * <p>
+ * Unlike MessageDigest, this implementation includes the algorithm used by
+ * {@code sha1dc} to detect cryptanalytic collision attacks against SHA-1, such
+ * as the one used by <a href="https://shattered.it/">SHAttered</a>. See
+ * <a href="https://github.com/cr-marcstevens/sha1collisiondetection">
+ * sha1collisiondetection</a> for more information.
+ * <p>
+ * When detectCollision is true (default), this implementation throws
+ * {@link org.eclipse.jgit.util.sha1.Sha1CollisionException} from any digest
+ * method if a potential collision was detected.
+ *
+ * @since 4.7
+ */
+class SHA1Java extends SHA1 {
+ private static final Logger LOG = LoggerFactory.getLogger(SHA1Java.class);
+ private static final boolean DETECT_COLLISIONS;
+
+ static {
+ SystemReader sr = SystemReader.getInstance();
+ String v = sr.getProperty("org.eclipse.jgit.util.sha1.detectCollision"); //$NON-NLS-1$
+ DETECT_COLLISIONS = v != null ? Boolean.parseBoolean(v) : true;
+ }
+
+ private final State h = new State();
+ private final int[] w = new int[80];
+
+ /** Buffer to accumulate partial blocks to 64 byte alignment. */
+ private final byte[] buffer = new byte[64];
+
+ /** Total number of bytes in the message. */
+ private long length;
+
+ private boolean detectCollision = DETECT_COLLISIONS;
+ private boolean foundCollision;
+
+ private final int[] w2 = new int[80];
+ private final State state58 = new State();
+ private final State state65 = new State();
+ private final State hIn = new State();
+ private final State hTmp = new State();
+
+ SHA1Java() {
+ h.init();
+ }
+
+ /**
+ * Enable likely collision detection.
+ * <p>
+ * Default is {@code true}.
+ * <p>
+ * May also be set by system property:
+ * {@code -Dorg.eclipse.jgit.util.sha1.detectCollision=true}.
+ *
+ * @param detect
+ * a boolean.
+ * @return {@code this}
+ */
+ @Override
+ public SHA1 setDetectCollision(boolean detect) {
+ detectCollision = detect;
+ return this;
+ }
+
+ /**
+ * Update the digest computation by adding a byte.
+ *
+ * @param b a byte.
+ */
+ @Override
+ public void update(byte b) {
+ int bufferLen = (int) (length & 63);
+ length++;
+ buffer[bufferLen] = b;
+ if (bufferLen == 63) {
+ compress(buffer, 0);
+ }
+ }
+
+ /**
+ * Update the digest computation by adding bytes to the message.
+ *
+ * @param in
+ * input array of bytes.
+ */
+ @Override
+ public void update(byte[] in) {
+ update(in, 0, in.length);
+ }
+
+ /**
+ * Update the digest computation by adding bytes to the message.
+ *
+ * @param in
+ * input array of bytes.
+ * @param p
+ * offset to start at from {@code in}.
+ * @param len
+ * number of bytes to hash.
+ */
+ @Override
+ public void update(byte[] in, int p, int len) {
+ // SHA-1 compress can only process whole 64 byte blocks.
+ // Hold partial updates in buffer, whose length is the low bits.
+ int bufferLen = (int) (length & 63);
+ length += len;
+
+ if (bufferLen > 0) {
+ int n = Math.min(64 - bufferLen, len);
+ System.arraycopy(in, p, buffer, bufferLen, n);
+ p += n;
+ len -= n;
+ if (bufferLen + n < 64) {
+ return;
+ }
+ compress(buffer, 0);
+ }
+ while (len >= 64) {
+ compress(in, p);
+ p += 64;
+ len -= 64;
+ }
+ if (len > 0) {
+ System.arraycopy(in, p, buffer, 0, len);
+ }
+ }
+
+ private void compress(byte[] block, int p) {
+ initBlock(block, p);
+ int ubcDvMask = detectCollision ? UbcCheck.check(w) : 0;
+ compress();
+
+ while (ubcDvMask != 0) {
+ int b = numberOfTrailingZeros(lowestOneBit(ubcDvMask));
+ UbcCheck.DvInfo dv = UbcCheck.DV[b];
+ for (int i = 0; i < 80; i++) {
+ w2[i] = w[i] ^ dv.dm[i];
+ }
+ recompress(dv.testt);
+ if (eq(hTmp, h)) {
+ foundCollision = true;
+ break;
+ }
+ ubcDvMask &= ~(1 << b);
+ }
+ }
+
+ private void initBlock(byte[] block, int p) {
+ for (int t = 0; t < 16; t++) {
+ w[t] = NB.decodeInt32(block, p + (t << 2));
+ }
+
+ // RFC 3174 6.1.b, extend state vector to 80 words.
+ for (int t = 16; t < 80; t++) {
+ int x = w[t - 3] ^ w[t - 8] ^ w[t - 14] ^ w[t - 16];
+ w[t] = rotateLeft(x, 1); // S^1(...)
+ }
+ }
+
+ private void compress() {
+ // Method 1 from RFC 3174 section 6.1.
+ // Method 2 (circular queue of 16 words) is slower.
+ int a = h.a, b = h.b, c = h.c, d = h.d, e = h.e;
+
+ // @formatter:off
+ e += s1(a, b, c, d,w[ 0]); b = rotateLeft( b, 30);
+ d += s1(e, a, b, c,w[ 1]); a = rotateLeft( a, 30);
+ c += s1(d, e, a, b,w[ 2]); e = rotateLeft( e, 30);
+ b += s1(c, d, e, a,w[ 3]); d = rotateLeft( d, 30);
+ a += s1(b, c, d, e,w[ 4]); c = rotateLeft( c, 30);
+ e += s1(a, b, c, d,w[ 5]); b = rotateLeft( b, 30);
+ d += s1(e, a, b, c,w[ 6]); a = rotateLeft( a, 30);
+ c += s1(d, e, a, b,w[ 7]); e = rotateLeft( e, 30);
+ b += s1(c, d, e, a,w[ 8]); d = rotateLeft( d, 30);
+ a += s1(b, c, d, e,w[ 9]); c = rotateLeft( c, 30);
+ e += s1(a, b, c, d,w[ 10]); b = rotateLeft( b, 30);
+ d += s1(e, a, b, c,w[ 11]); a = rotateLeft( a, 30);
+ c += s1(d, e, a, b,w[ 12]); e = rotateLeft( e, 30);
+ b += s1(c, d, e, a,w[ 13]); d = rotateLeft( d, 30);
+ a += s1(b, c, d, e,w[ 14]); c = rotateLeft( c, 30);
+ e += s1(a, b, c, d,w[ 15]); b = rotateLeft( b, 30);
+ d += s1(e, a, b, c,w[ 16]); a = rotateLeft( a, 30);
+ c += s1(d, e, a, b,w[ 17]); e = rotateLeft( e, 30);
+ b += s1(c, d, e, a,w[ 18]); d = rotateLeft( d, 30);
+ a += s1(b, c, d, e,w[ 19]); c = rotateLeft( c, 30);
+
+ e += s2(a, b, c, d,w[ 20]); b = rotateLeft( b, 30);
+ d += s2(e, a, b, c,w[ 21]); a = rotateLeft( a, 30);
+ c += s2(d, e, a, b,w[ 22]); e = rotateLeft( e, 30);
+ b += s2(c, d, e, a,w[ 23]); d = rotateLeft( d, 30);
+ a += s2(b, c, d, e,w[ 24]); c = rotateLeft( c, 30);
+ e += s2(a, b, c, d,w[ 25]); b = rotateLeft( b, 30);
+ d += s2(e, a, b, c,w[ 26]); a = rotateLeft( a, 30);
+ c += s2(d, e, a, b,w[ 27]); e = rotateLeft( e, 30);
+ b += s2(c, d, e, a,w[ 28]); d = rotateLeft( d, 30);
+ a += s2(b, c, d, e,w[ 29]); c = rotateLeft( c, 30);
+ e += s2(a, b, c, d,w[ 30]); b = rotateLeft( b, 30);
+ d += s2(e, a, b, c,w[ 31]); a = rotateLeft( a, 30);
+ c += s2(d, e, a, b,w[ 32]); e = rotateLeft( e, 30);
+ b += s2(c, d, e, a,w[ 33]); d = rotateLeft( d, 30);
+ a += s2(b, c, d, e,w[ 34]); c = rotateLeft( c, 30);
+ e += s2(a, b, c, d,w[ 35]); b = rotateLeft( b, 30);
+ d += s2(e, a, b, c,w[ 36]); a = rotateLeft( a, 30);
+ c += s2(d, e, a, b,w[ 37]); e = rotateLeft( e, 30);
+ b += s2(c, d, e, a,w[ 38]); d = rotateLeft( d, 30);
+ a += s2(b, c, d, e,w[ 39]); c = rotateLeft( c, 30);
+
+ e += s3(a, b, c, d,w[ 40]); b = rotateLeft( b, 30);
+ d += s3(e, a, b, c,w[ 41]); a = rotateLeft( a, 30);
+ c += s3(d, e, a, b,w[ 42]); e = rotateLeft( e, 30);
+ b += s3(c, d, e, a,w[ 43]); d = rotateLeft( d, 30);
+ a += s3(b, c, d, e,w[ 44]); c = rotateLeft( c, 30);
+ e += s3(a, b, c, d,w[ 45]); b = rotateLeft( b, 30);
+ d += s3(e, a, b, c,w[ 46]); a = rotateLeft( a, 30);
+ c += s3(d, e, a, b,w[ 47]); e = rotateLeft( e, 30);
+ b += s3(c, d, e, a,w[ 48]); d = rotateLeft( d, 30);
+ a += s3(b, c, d, e,w[ 49]); c = rotateLeft( c, 30);
+ e += s3(a, b, c, d,w[ 50]); b = rotateLeft( b, 30);
+ d += s3(e, a, b, c,w[ 51]); a = rotateLeft( a, 30);
+ c += s3(d, e, a, b,w[ 52]); e = rotateLeft( e, 30);
+ b += s3(c, d, e, a,w[ 53]); d = rotateLeft( d, 30);
+ a += s3(b, c, d, e,w[ 54]); c = rotateLeft( c, 30);
+ e += s3(a, b, c, d,w[ 55]); b = rotateLeft( b, 30);
+ d += s3(e, a, b, c,w[ 56]); a = rotateLeft( a, 30);
+ c += s3(d, e, a, b,w[ 57]); e = rotateLeft( e, 30);
+ state58.save(a, b, c, d, e);
+ b += s3(c, d, e, a,w[ 58]); d = rotateLeft( d, 30);
+ a += s3(b, c, d, e,w[ 59]); c = rotateLeft( c, 30);
+
+ e += s4(a, b, c, d,w[ 60]); b = rotateLeft( b, 30);
+ d += s4(e, a, b, c,w[ 61]); a = rotateLeft( a, 30);
+ c += s4(d, e, a, b,w[ 62]); e = rotateLeft( e, 30);
+ b += s4(c, d, e, a,w[ 63]); d = rotateLeft( d, 30);
+ a += s4(b, c, d, e,w[ 64]); c = rotateLeft( c, 30);
+ state65.save(a, b, c, d, e);
+ e += s4(a, b, c, d,w[ 65]); b = rotateLeft( b, 30);
+ d += s4(e, a, b, c,w[ 66]); a = rotateLeft( a, 30);
+ c += s4(d, e, a, b,w[ 67]); e = rotateLeft( e, 30);
+ b += s4(c, d, e, a,w[ 68]); d = rotateLeft( d, 30);
+ a += s4(b, c, d, e,w[ 69]); c = rotateLeft( c, 30);
+ e += s4(a, b, c, d,w[ 70]); b = rotateLeft( b, 30);
+ d += s4(e, a, b, c,w[ 71]); a = rotateLeft( a, 30);
+ c += s4(d, e, a, b,w[ 72]); e = rotateLeft( e, 30);
+ b += s4(c, d, e, a,w[ 73]); d = rotateLeft( d, 30);
+ a += s4(b, c, d, e,w[ 74]); c = rotateLeft( c, 30);
+ e += s4(a, b, c, d,w[ 75]); b = rotateLeft( b, 30);
+ d += s4(e, a, b, c,w[ 76]); a = rotateLeft( a, 30);
+ c += s4(d, e, a, b,w[ 77]); e = rotateLeft( e, 30);
+ b += s4(c, d, e, a,w[ 78]); d = rotateLeft( d, 30);
+ a += s4(b, c, d, e,w[ 79]); c = rotateLeft( c, 30);
+
+ // @formatter:on
+ h.save(h.a + a, h.b + b, h.c + c, h.d + d, h.e + e);
+ }
+
+ private void recompress(int t) {
+ State s;
+ switch (t) {
+ case 58:
+ s = state58;
+ break;
+ case 65:
+ s = state65;
+ break;
+ default:
+ throw new IllegalStateException();
+ }
+ int a = s.a, b = s.b, c = s.c, d = s.d, e = s.e;
+
+ // @formatter:off
+ if (t == 65) {
+ { c = rotateRight( c, 30); a -= s4(b, c, d, e,w2[ 64]);}
+ { d = rotateRight( d, 30); b -= s4(c, d, e, a,w2[ 63]);}
+ { e = rotateRight( e, 30); c -= s4(d, e, a, b,w2[ 62]);}
+ { a = rotateRight( a, 30); d -= s4(e, a, b, c,w2[ 61]);}
+ { b = rotateRight( b, 30); e -= s4(a, b, c, d,w2[ 60]);}
+
+ { c = rotateRight( c, 30); a -= s3(b, c, d, e,w2[ 59]);}
+ { d = rotateRight( d, 30); b -= s3(c, d, e, a,w2[ 58]);}
+ }
+ { e = rotateRight( e, 30); c -= s3(d, e, a, b,w2[ 57]);}
+ { a = rotateRight( a, 30); d -= s3(e, a, b, c,w2[ 56]);}
+ { b = rotateRight( b, 30); e -= s3(a, b, c, d,w2[ 55]);}
+ { c = rotateRight( c, 30); a -= s3(b, c, d, e,w2[ 54]);}
+ { d = rotateRight( d, 30); b -= s3(c, d, e, a,w2[ 53]);}
+ { e = rotateRight( e, 30); c -= s3(d, e, a, b,w2[ 52]);}
+ { a = rotateRight( a, 30); d -= s3(e, a, b, c,w2[ 51]);}
+ { b = rotateRight( b, 30); e -= s3(a, b, c, d,w2[ 50]);}
+ { c = rotateRight( c, 30); a -= s3(b, c, d, e,w2[ 49]);}
+ { d = rotateRight( d, 30); b -= s3(c, d, e, a,w2[ 48]);}
+ { e = rotateRight( e, 30); c -= s3(d, e, a, b,w2[ 47]);}
+ { a = rotateRight( a, 30); d -= s3(e, a, b, c,w2[ 46]);}
+ { b = rotateRight( b, 30); e -= s3(a, b, c, d,w2[ 45]);}
+ { c = rotateRight( c, 30); a -= s3(b, c, d, e,w2[ 44]);}
+ { d = rotateRight( d, 30); b -= s3(c, d, e, a,w2[ 43]);}
+ { e = rotateRight( e, 30); c -= s3(d, e, a, b,w2[ 42]);}
+ { a = rotateRight( a, 30); d -= s3(e, a, b, c,w2[ 41]);}
+ { b = rotateRight( b, 30); e -= s3(a, b, c, d,w2[ 40]);}
+
+ { c = rotateRight( c, 30); a -= s2(b, c, d, e,w2[ 39]);}
+ { d = rotateRight( d, 30); b -= s2(c, d, e, a,w2[ 38]);}
+ { e = rotateRight( e, 30); c -= s2(d, e, a, b,w2[ 37]);}
+ { a = rotateRight( a, 30); d -= s2(e, a, b, c,w2[ 36]);}
+ { b = rotateRight( b, 30); e -= s2(a, b, c, d,w2[ 35]);}
+ { c = rotateRight( c, 30); a -= s2(b, c, d, e,w2[ 34]);}
+ { d = rotateRight( d, 30); b -= s2(c, d, e, a,w2[ 33]);}
+ { e = rotateRight( e, 30); c -= s2(d, e, a, b,w2[ 32]);}
+ { a = rotateRight( a, 30); d -= s2(e, a, b, c,w2[ 31]);}
+ { b = rotateRight( b, 30); e -= s2(a, b, c, d,w2[ 30]);}
+ { c = rotateRight( c, 30); a -= s2(b, c, d, e,w2[ 29]);}
+ { d = rotateRight( d, 30); b -= s2(c, d, e, a,w2[ 28]);}
+ { e = rotateRight( e, 30); c -= s2(d, e, a, b,w2[ 27]);}
+ { a = rotateRight( a, 30); d -= s2(e, a, b, c,w2[ 26]);}
+ { b = rotateRight( b, 30); e -= s2(a, b, c, d,w2[ 25]);}
+ { c = rotateRight( c, 30); a -= s2(b, c, d, e,w2[ 24]);}
+ { d = rotateRight( d, 30); b -= s2(c, d, e, a,w2[ 23]);}
+ { e = rotateRight( e, 30); c -= s2(d, e, a, b,w2[ 22]);}
+ { a = rotateRight( a, 30); d -= s2(e, a, b, c,w2[ 21]);}
+ { b = rotateRight( b, 30); e -= s2(a, b, c, d,w2[ 20]);}
+
+ { c = rotateRight( c, 30); a -= s1(b, c, d, e,w2[ 19]);}
+ { d = rotateRight( d, 30); b -= s1(c, d, e, a,w2[ 18]);}
+ { e = rotateRight( e, 30); c -= s1(d, e, a, b,w2[ 17]);}
+ { a = rotateRight( a, 30); d -= s1(e, a, b, c,w2[ 16]);}
+ { b = rotateRight( b, 30); e -= s1(a, b, c, d,w2[ 15]);}
+ { c = rotateRight( c, 30); a -= s1(b, c, d, e,w2[ 14]);}
+ { d = rotateRight( d, 30); b -= s1(c, d, e, a,w2[ 13]);}
+ { e = rotateRight( e, 30); c -= s1(d, e, a, b,w2[ 12]);}
+ { a = rotateRight( a, 30); d -= s1(e, a, b, c,w2[ 11]);}
+ { b = rotateRight( b, 30); e -= s1(a, b, c, d,w2[ 10]);}
+ { c = rotateRight( c, 30); a -= s1(b, c, d, e,w2[ 9]);}
+ { d = rotateRight( d, 30); b -= s1(c, d, e, a,w2[ 8]);}
+ { e = rotateRight( e, 30); c -= s1(d, e, a, b,w2[ 7]);}
+ { a = rotateRight( a, 30); d -= s1(e, a, b, c,w2[ 6]);}
+ { b = rotateRight( b, 30); e -= s1(a, b, c, d,w2[ 5]);}
+ { c = rotateRight( c, 30); a -= s1(b, c, d, e,w2[ 4]);}
+ { d = rotateRight( d, 30); b -= s1(c, d, e, a,w2[ 3]);}
+ { e = rotateRight( e, 30); c -= s1(d, e, a, b,w2[ 2]);}
+ { a = rotateRight( a, 30); d -= s1(e, a, b, c,w2[ 1]);}
+ { b = rotateRight( b, 30); e -= s1(a, b, c, d,w2[ 0]);}
+
+ hIn.save(a, b, c, d, e);
+ a = s.a; b = s.b; c = s.c; d = s.d; e = s.e;
+
+ if (t == 58) {
+ { b += s3(c, d, e, a,w2[ 58]); d = rotateLeft( d, 30);}
+ { a += s3(b, c, d, e,w2[ 59]); c = rotateLeft( c, 30);}
+
+ { e += s4(a, b, c, d,w2[ 60]); b = rotateLeft( b, 30);}
+ { d += s4(e, a, b, c,w2[ 61]); a = rotateLeft( a, 30);}
+ { c += s4(d, e, a, b,w2[ 62]); e = rotateLeft( e, 30);}
+ { b += s4(c, d, e, a,w2[ 63]); d = rotateLeft( d, 30);}
+ { a += s4(b, c, d, e,w2[ 64]); c = rotateLeft( c, 30);}
+ }
+ { e += s4(a, b, c, d,w2[ 65]); b = rotateLeft( b, 30);}
+ { d += s4(e, a, b, c,w2[ 66]); a = rotateLeft( a, 30);}
+ { c += s4(d, e, a, b,w2[ 67]); e = rotateLeft( e, 30);}
+ { b += s4(c, d, e, a,w2[ 68]); d = rotateLeft( d, 30);}
+ { a += s4(b, c, d, e,w2[ 69]); c = rotateLeft( c, 30);}
+ { e += s4(a, b, c, d,w2[ 70]); b = rotateLeft( b, 30);}
+ { d += s4(e, a, b, c,w2[ 71]); a = rotateLeft( a, 30);}
+ { c += s4(d, e, a, b,w2[ 72]); e = rotateLeft( e, 30);}
+ { b += s4(c, d, e, a,w2[ 73]); d = rotateLeft( d, 30);}
+ { a += s4(b, c, d, e,w2[ 74]); c = rotateLeft( c, 30);}
+ { e += s4(a, b, c, d,w2[ 75]); b = rotateLeft( b, 30);}
+ { d += s4(e, a, b, c,w2[ 76]); a = rotateLeft( a, 30);}
+ { c += s4(d, e, a, b,w2[ 77]); e = rotateLeft( e, 30);}
+ { b += s4(c, d, e, a,w2[ 78]); d = rotateLeft( d, 30);}
+ { a += s4(b, c, d, e,w2[ 79]); c = rotateLeft( c, 30);}
+
+ // @formatter:on
+ hTmp.save(hIn.a + a, hIn.b + b, hIn.c + c, hIn.d + d, hIn.e + e);
+ }
+
+ private static int s1(int a, int b, int c, int d, int w_t) {
+ return rotateLeft(a, 5)
+ // f: 0 <= t <= 19
+ + ((b & c) | ((~b) & d))
+ + 0x5A827999 + w_t;
+ }
+
+ private static int s2(int a, int b, int c, int d, int w_t) {
+ return rotateLeft(a, 5)
+ // f: 20 <= t <= 39
+ + (b ^ c ^ d)
+ + 0x6ED9EBA1 + w_t;
+ }
+
+ private static int s3(int a, int b, int c, int d, int w_t) {
+ return rotateLeft(a, 5)
+ // f: 40 <= t <= 59
+ + ((b & c) | (b & d) | (c & d))
+ + 0x8F1BBCDC + w_t;
+ }
+
+ private static int s4(int a, int b, int c, int d, int w_t) {
+ return rotateLeft(a, 5)
+ // f: 60 <= t <= 79
+ + (b ^ c ^ d)
+ + 0xCA62C1D6 + w_t;
+ }
+
+ private static boolean eq(State q, State r) {
+ return q.a == r.a
+ && q.b == r.b
+ && q.c == r.c
+ && q.d == r.d
+ && q.e == r.e;
+ }
+
+ private void finish() {
+ int bufferLen = (int) (length & 63);
+ if (bufferLen > 55) {
+ // Last block is too small; pad, compress, pad another block.
+ buffer[bufferLen++] = (byte) 0x80;
+ Arrays.fill(buffer, bufferLen, 64, (byte) 0);
+ compress(buffer, 0);
+ Arrays.fill(buffer, 0, 56, (byte) 0);
+ } else {
+ // Last block can hold padding and length.
+ buffer[bufferLen++] = (byte) 0x80;
+ Arrays.fill(buffer, bufferLen, 56, (byte) 0);
+ }
+
+ // SHA-1 appends the length of the message in bits after the
+ // padding block (above). Here length is in bytes. Multiply by
+ // 8 by shifting by 3 as part of storing the 64 bit byte length
+ // into the two words expected in the trailer.
+ NB.encodeInt32(buffer, 56, (int) (length >>> (32 - 3)));
+ NB.encodeInt32(buffer, 60, (int) (length << 3));
+ compress(buffer, 0);
+
+ if (foundCollision) {
+ ObjectId id = h.toObjectId();
+ LOG.warn(MessageFormat.format(JGitText.get().sha1CollisionDetected,
+ id.name()));
+ throw new Sha1CollisionException(id);
+ }
+ }
+
+ /**
+ * Finish the digest and return the resulting hash.
+ * <p>
+ * Once {@code digest()} is called, this instance should be discarded.
+ *
+ * @return the bytes for the resulting hash.
+ * @throws org.eclipse.jgit.util.sha1.Sha1CollisionException
+ * if a collision was detected and safeHash is false.
+ */
+ @Override
+ public byte[] digest() throws Sha1CollisionException {
+ finish();
+
+ byte[] b = new byte[20];
+ NB.encodeInt32(b, 0, h.a);
+ NB.encodeInt32(b, 4, h.b);
+ NB.encodeInt32(b, 8, h.c);
+ NB.encodeInt32(b, 12, h.d);
+ NB.encodeInt32(b, 16, h.e);
+ return b;
+ }
+
+ /**
+ * Finish the digest and return the resulting hash.
+ * <p>
+ * Once {@code digest()} is called, this instance should be discarded.
+ *
+ * @return the ObjectId for the resulting hash.
+ * @throws org.eclipse.jgit.util.sha1.Sha1CollisionException
+ * if a collision was detected and safeHash is false.
+ */
+ @Override
+ public ObjectId toObjectId() throws Sha1CollisionException {
+ finish();
+ return h.toObjectId();
+ }
+
+ /**
+ * Finish the digest and return the resulting hash.
+ * <p>
+ * Once {@code digest()} is called, this instance should be discarded.
+ *
+ * @param id
+ * destination to copy the digest to.
+ * @throws org.eclipse.jgit.util.sha1.Sha1CollisionException
+ * if a collision was detected and safeHash is false.
+ */
+ @Override
+ public void digest(MutableObjectId id) throws Sha1CollisionException {
+ finish();
+ id.set(h.a, h.b, h.c, h.d, h.e);
+ }
+
+ /**
+ * Check if a collision was detected.
+ *
+ * <p>
+ * This method only returns an accurate result after the digest was obtained
+ * through {@link #digest()}, {@link #digest(MutableObjectId)} or
+ * {@link #toObjectId()}, as the hashing function must finish processing to
+ * know the final state.
+ *
+ * @return {@code true} if a likely collision was detected.
+ */
+ @Override
+ public boolean hasCollision() {
+ return foundCollision;
+ }
+
+ /**
+ * Reset this instance to compute another hash.
+ *
+ * @return {@code this}.
+ */
+ @Override
+ public SHA1 reset() {
+ h.init();
+ length = 0;
+ foundCollision = false;
+ return this;
+ }
+
+ private static final class State {
+ int a;
+ int b;
+ int c;
+ int d;
+ int e;
+
+ final void init() {
+ // Magic initialization constants defined by FIPS180.
+ save(0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0);
+ }
+
+ final void save(int a1, int b1, int c1, int d1, int e1) {
+ a = a1;
+ b = b1;
+ c = c1;
+ d = d1;
+ e = e1;
+ }
+
+ ObjectId toObjectId() {
+ return new ObjectId(a, b, c, d, e);
+ }
+ }
+}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1Native.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1Native.java
new file mode 100644
index 0000000..4599ac0
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1Native.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2022, Matthias Sohn <matthias.sohn@sap.com> and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0 which is available at
+ * https://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+package org.eclipse.jgit.util.sha1;
+
+import java.security.MessageDigest;
+
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.MutableObjectId;
+import org.eclipse.jgit.lib.ObjectId;
+
+/**
+ * SHA1 implementation using native implementation from JDK. It doesn't support
+ * collision detection but is faster than the pure Java implementation.
+ */
+class SHA1Native extends SHA1 {
+
+ private final MessageDigest md;
+
+ SHA1Native() {
+ md = Constants.newMessageDigest();
+ }
+
+ @Override
+ public void update(byte b) {
+ md.update(b);
+ }
+
+ @Override
+ public void update(byte[] in) {
+ md.update(in);
+ }
+
+ @Override
+ public void update(byte[] in, int p, int len) {
+ md.update(in, p, len);
+ }
+
+ @Override
+ public byte[] digest() throws Sha1CollisionException {
+ return md.digest();
+ }
+
+ @Override
+ public ObjectId toObjectId() throws Sha1CollisionException {
+ return ObjectId.fromRaw(md.digest());
+ }
+
+ @Override
+ public void digest(MutableObjectId id) throws Sha1CollisionException {
+ id.fromRaw(md.digest());
+ }
+
+ @Override
+ public SHA1 reset() {
+ md.reset();
+ return this;
+ }
+
+ @Override
+ public SHA1 setDetectCollision(boolean detect) {
+ return this;
+ }
+
+ @Override
+ public boolean hasCollision() {
+ return false;
+ }
+}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/Sha1CollisionException.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/Sha1CollisionException.java
index ce95ba5..fc8d7ab 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/Sha1CollisionException.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/Sha1CollisionException.java
@@ -16,7 +16,7 @@
import org.eclipse.jgit.lib.ObjectId;
/**
- * Thrown by {@link org.eclipse.jgit.util.sha1.SHA1} if it detects a likely hash
+ * Thrown by {@link org.eclipse.jgit.util.sha1.SHA1Java} if it detects a likely hash
* collision.
*
* @since 4.7
