Implement Digest::CRC32

Rakefile

@@ -24,7 +24,7 @@ if RUBY_ENGINE == "jruby"
 else
   require "rake/extensiontask"
   Rake::ExtensionTask.new("digest")
-  %w[bubblebabble md5 rmd160 sha1 sha2].each do |ext|
+  %w[bubblebabble md5 rmd160 sha1 sha2 crc32].each do |ext|
     Rake::ExtensionTask.new("digest/#{ext}")
   end
 end

ext/digest/crc32/crc32.c

@@ -0,0 +1,66 @@
+#include "crc32.h"
+
+static const uint32_t crc32_table[256] = {
+    0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
+    0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
+    0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+    0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
+    0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+    0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+    0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
+    0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
+    0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+    0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+    0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
+    0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+    0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
+    0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
+    0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+    0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
+    0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
+    0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+    0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
+    0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+    0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+    0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
+    0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
+    0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+    0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+    0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
+    0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+    0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
+    0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
+    0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+    0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
+    0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
+};
+
+int
+CRC32_Init(CRC32_CTX *context)
+{
+    context->state = 0xFFFFFFFFu;
+    return 1;
+}
+
+void
+CRC32_Update(CRC32_CTX *context, const uint8_t *data, size_t nbytes)
+{
+    uint32_t state = context->state;
+    for (size_t index = 0; index < nbytes; index++) {
+        state ^= data[index];
+        state = (state >> 8) ^ crc32_table[state & 0xff];
+    }
+    context->state = state;
+}
+
+int
+CRC32_Finish(CRC32_CTX *context, uint8_t digest[4])
+{
+    uint32_t state = context->state;
+    state ^= 0xFFFFFFFFu;
+    digest[3] = state & 0xff;
+    digest[2] = (state >> 8) & 0xff;
+    digest[1] = (state >> 16) & 0xff;
+    digest[0] = (state >> 24) & 0xff;
+    return 1;
+}

ext/digest/crc32/crc32.h

@@ -0,0 +1,26 @@
+#ifndef _CRC32_H_
+#define _CRC32_H_
+
+#include "../defs.h"
+
+typedef struct {
+    uint32_t state;
+} CRC32_CTX;
+
+#ifdef RUBY
+#define CRC32_Init	rb_Digest_CRC32_Init
+#define CRC32_Update	rb_Digest_CRC32_Update
+#define CRC32_Finish	rb_Digest_CRC32_Finish
+#endif
+
+__BEGIN_DECLS
+int	CRC32_Init _((CRC32_CTX *));
+void	CRC32_Update _((CRC32_CTX *, const uint8_t *, size_t));
+int	CRC32_Finish _((CRC32_CTX *, uint8_t[4]));
+__END_DECLS
+
+#define CRC32_BLOCK_LENGTH             8
+#define CRC32_DIGEST_LENGTH            4
+#define CRC32_DIGEST_STRING_LENGTH     (CRC32_DIGEST_LENGTH * 2 + 1)
+
+#endif  /* !_CRC32_H_ */

ext/digest/crc32/crc32init.c

@@ -0,0 +1,54 @@
+/* $RoughId: crc32init.c,v 1.3 2001/07/13 20:00:43 knu Exp $ */
+/* $Id$ */
+
+#include <ruby/ruby.h>
+#include "../digest.h"
+#include "crc32.h"
+
+static const rb_digest_metadata_t crc32 = {
+    RUBY_DIGEST_API_VERSION,
+    CRC32_DIGEST_LENGTH,
+    CRC32_BLOCK_LENGTH,
+    sizeof(CRC32_CTX),
+    (rb_digest_hash_init_func_t)CRC32_Init,
+    (rb_digest_hash_update_func_t)CRC32_Update,
+    (rb_digest_hash_finish_func_t)CRC32_Finish,
+};
+
+/*
+ * Document-class: Digest::CRC32 < Digest::Base
+ * A class for calculating message digests using CRC32 algorithm.
+ *
+ * CRC32 calculates a digest of 32 bits (4 bytes).
+ *
+ * == Examples
+ *  require 'digest'
+ *
+ *  # Compute a complete digest
+ *  Digest::CRC32.hexdigest 'abc'      #=> "8eb208f7..."
+ *
+ *  # Compute digest by chunks
+ *  crc32 = Digest::CRC32.new               # =>#<Digest::CRC32>
+ *  crc32.update "ab"
+ *  crc32 << "c"                           # alias for #update
+ *  crc32.hexdigest                        # => "352441c2"
+ *
+ *  # Use the same object to compute another digest
+ *  crc32.reset
+ *  crc32 << "message"
+ *  crc32.hexdigest                        # => "b6bd307f"
+ */
+void
+Init_crc32(void)
+{
+    VALUE mDigest, cDigest_Base, cDigest_CRC32;
+
+#if 0
+    mDigest = rb_define_module("Digest"); /* let rdoc know */
+#endif
+    mDigest = rb_digest_namespace();
+    cDigest_Base = rb_const_get(mDigest, rb_intern_const("Base"));
+
+    cDigest_CRC32 = rb_define_class_under(mDigest, "CRC32", cDigest_Base);
+    rb_iv_set(cDigest_CRC32, "metadata", rb_digest_make_metadata(&crc32));
+}

ext/digest/crc32/extconf.rb

@@ -0,0 +1,21 @@
+# -*- coding: us-ascii -*-
+# frozen_string_literal: false
+# $RoughId: extconf.rb,v 1.3 2001/08/14 19:54:51 knu Exp $
+# $Id$
+
+require "mkmf"
+require File.expand_path("../../digest_conf", __FILE__)
+
+if try_static_assert("RUBY_API_VERSION_MAJOR < 3", "ruby/version.h")
+  $defs << "-DNDEBUG"
+end
+
+$objs = [ "crc32init.#{$OBJEXT}" ]
+
+digest_conf("crc32")
+
+have_header("sys/cdefs.h")
+
+$preload = %w[digest]
+
+create_makefile("digest/crc32")

test/digest/test_digest.rb

@@ -6,7 +6,7 @@
 require 'tempfile'
 
 require 'digest'
-%w[digest/md5 digest/rmd160 digest/sha1 digest/sha2 digest/bubblebabble].each do |lib|
+%w[digest/md5 digest/rmd160 digest/sha1 digest/sha2 digest/bubblebabble digest/crc32].each do |lib|
   begin
     require lib
   rescue LoadError
@@ -197,6 +197,15 @@ class TestRMD160 < Test::Unit::TestCase
     }
   end if defined?(Digest::RMD160)
 
+  class TestCRC32 < Test::Unit::TestCase
+    include TestDigest
+    ALGO = Digest::CRC32
+    DATA = {
+      Data1 => "352441c2",
+      Data2 => "171a3f5f",
+    }
+  end
+
   class TestBase < Test::Unit::TestCase
     def test_base
       bug3810 = '[ruby-core:32231]'