github
/
jgit
mirror of https://gitee.com/github-mirror-repo/jgit.git
1
0
Fork 0
Code Issues Releases Wiki Activity
Browse Source

Pure Java SHA-1 

This implementation is derived straight from the description written
in RFC 3174.  On Mac OS X with Java 1.8.0_91 it offers similar
throughput as MessageDigest SHA-1:

  system   239.75 MiB/s
  system   244.71 MiB/s
  system   245.00 MiB/s
  system   244.92 MiB/s

  sha1     234.08 MiB/s
  sha1     244.50 MiB/s
  sha1     242.99 MiB/s
  sha1     241.73 MiB/s

This is the fastest implementation I could come up with.  Common SHA-1
implementation tricks such as unrolling loops creates a method too
large for the JIT to effectively optimize, resulting in lower overall
hashing throughput. Using a preprocessor to perform the register
renaming of A-E also didn't help, as again the method was too large
for the JIT to effectively optimize.

Fortunately the fastest version is a naive, straight-forward
implementation very close to the description in RFC 3174.

Change-Id: I228b05c4a294ca2ad51386cf0e47978c68e1aa42
stable-4.7
Shawn Pearce 8 years ago
parent
9af93f43cc
commit
982f5d1bf1
4 changed files with 376 additions and 0 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 1
      org.eclipse.jgit.test/META-INF/MANIFEST.MF
  2. 112
      org.eclipse.jgit.test/tst/org/eclipse/jgit/util/sha1/SHA1Test.java
  3. 1
      org.eclipse.jgit/META-INF/MANIFEST.MF
  4. 262
      org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1.java

1
org.eclipse.jgit.test/META-INF/MANIFEST.MF
Unescape View File

@ -49,6 +49,7 @@ Import-Package: com.googlecode.javaewah;version="[1.1.6,2.0.0)",
org.eclipse.jgit.treewalk.filter;version="[4.7.0,4.8.0)",
org.eclipse.jgit.util;version="[4.7.0,4.8.0)",
org.eclipse.jgit.util.io;version="[4.7.0,4.8.0)",
org.eclipse.jgit.util.sha1;version="[4.7.0,4.8.0)",
org.junit;version="[4.4.0,5.0.0)",
org.junit.experimental.theories;version="[4.4.0,5.0.0)",
org.junit.rules;version="[4.11.0,5.0.0)",

112
org.eclipse.jgit.test/tst/org/eclipse/jgit/util/sha1/SHA1Test.java
Unescape View File

@ -0,0 +1,112 @@
/*
* 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 java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.eclipse.jgit.lib.ObjectId;
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());
assertEquals(m1, s1);
assertEquals(exp, s1);
}
@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());
assertEquals(m1, s1);
assertEquals(exp, s1);
}
@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());
assertEquals(m1, s1);
assertEquals(exp, s1);
}
}

1
org.eclipse.jgit/META-INF/MANIFEST.MF
Unescape View File

@ -138,6 +138,7 @@ Export-Package: org.eclipse.jgit.annotations;version="4.7.0",
org.eclipse.jgit.storage.file,
org.ietf.jgss",
org.eclipse.jgit.util.io;version="4.7.0",
org.eclipse.jgit.util.sha1;version="4.7.0",
org.eclipse.jgit.util.time;version="4.7.0"
Bundle-RequiredExecutionEnvironment: JavaSE-1.8
Import-Package: com.googlecode.javaewah;version="[1.1.6,2.0.0)",

262
org.eclipse.jgit/src/org/eclipse/jgit/util/sha1/SHA1.java
Unescape View File

@ -0,0 +1,262 @@
/*
* 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 java.util.Arrays;
import org.eclipse.jgit.util.NB;
/**
* 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>.
*
* @since 4.7
*/
public class SHA1 {
/** @return a new context to compute a SHA-1 hash of data. */
public static SHA1 newInstance() {
return new SHA1();
}
// Magic initialization constants defined by FIPS180.
private int h0 = 0x67452301;
private int h1 = 0xEFCDAB89;
private int h2 = 0x98BADCFE;
private int h3 = 0x10325476;
private int h4 = 0xC3D2E1F0;
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 SHA1() {
}
/**
* Update the digest computation by adding a byte.
*
* @param b
*/
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.
*/
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.
*/
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) {
// Method 1 from RFC 3174 section 6.1.
// Method 2 (circular queue of 16 words) is slower.
int a = h0, b = h1, c = h2, d = h3, e = h4;
// Round 1: 0 <= t <= 15 comes from the input block.
for (int t = 0; t < 16; t++) {
int temp = NB.decodeInt32(block, p + (t << 2));
w[t] = temp;
temp += ((a << 5) | (a >>> 27)) // S^5(A)
+ (((c ^ d) & b) ^ d) // f: 0 <= t <= 19
+ e + 0x5A827999;
e = d;
d = c;
c = (b << 30) | (b >>> 2); // S^30(B)
b = a;
a = temp;
}
// 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] = (x << 1) | (x >>> 31); // S^1(...)
}
// Round 1: tail
for (int t = 16; t < 20; t++) {
int temp = ((a << 5) | (a >>> 27)) // S^5(A)
+ (((c ^ d) & b) ^ d) // f: 0 <= t <= 19
+ e + w[t] + 0x5A827999;
e = d;
d = c;
c = (b << 30) | (b >>> 2); // S^30(B)
b = a;
a = temp;
}
// Round 2
for (int t = 20; t < 40; t++) {
int temp = ((a << 5) | (a >>> 27)) // S^5(A)
+ (b ^ c ^ d) // f: 20 <= t <= 39
+ e + w[t] + 0x6ED9EBA1;
e = d;
d = c;
c = (b << 30) | (b >>> 2); // S^30(B)
b = a;
a = temp;
}
// Round 3
for (int t = 40; t < 60; t++) {
int temp = ((a << 5) | (a >>> 27)) // S^5(A)
+ ((b & c) | (d & (b | c))) // f: 40 <= t <= 59
+ e + w[t] + 0x8F1BBCDC;
e = d;
d = c;
c = (b << 30) | (b >>> 2); // S^30(B)
b = a;
a = temp;
}
// Round 4
for (int t = 60; t < 80; t++) {
int temp = ((a << 5) | (a >>> 27)) // S^5(A)
+ (b ^ c ^ d) // f: 60 <= t <= 79
+ e + w[t] + 0xCA62C1D6;
e = d;
d = c;
c = (b << 30) | (b >>> 2); // S^30(B)
b = a;
a = temp;
}
h0 += a;
h1 += b;
h2 += c;
h3 += d;
h4 += 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);
}
/**
* 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.
*/
public byte[] digest() {
finish();
byte[] b = new byte[20];
NB.encodeInt32(b, 0, h0);
NB.encodeInt32(b, 4, h1);
NB.encodeInt32(b, 8, h2);
NB.encodeInt32(b, 12, h3);
NB.encodeInt32(b, 16, h4);
return b;
}
}
Write Preview
Loading…
Cancel
Save