XZ CRC64 and SHA256 support.

* Makefile.util.def (libgrubmods): Add crc64.c.
	* grub-core/Makefile.core.def (crc64): New module.
	* grub-core/lib/crc64.c: New file.
	* grub-core/lib/xzembed/xz_dec_stream.c (xz_dec_hash)
	[!GRUB_EMBED_DECOMPRESSOR]: Rename crc32_context to hash_context.
	Fix the type.
	(MAX_HASH_SIZE): New define.
	(xz_dec) [!GRUB_EMBED_DECOMPRESSOR]: Add generic hash fields.
	(dec_block) [!GRUB_EMBED_DECOMPRESSOR]: Handle non-crc32 hashes.
	(index_update) [!GRUB_EMBED_DECOMPRESSOR]: Likewise.
	(dec_index) [!GRUB_EMBED_DECOMPRESSOR]: Likewise.
	(crc32_validate) [!GRUB_EMBED_DECOMPRESSOR]: Rename to ...
	(hash_validate) [!GRUB_EMBED_DECOMPRESSOR]: ... this.
	Handle non-crc32 hashes.
	(hashes) [!GRUB_EMBED_DECOMPRESSOR]: New variable.
	(dec_stream_header): Handle non-crc32 hashes.
	(dec_stream_footer): Likewise.
	(dec_block_header): Likewise.
	(dec_main): Likewise.
	(xz_dec_init): Likewise.
	(xz_dec_reset): Likewise.
	(xz_dec_end): Likewise.
	* util/import_gcry.py: Add CRC64 line.

grub-core/lib/crc64.c

@@ -0,0 +1,111 @@
+/* crc64.c - crc64 function  */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2008,2011  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/types.h>
+#include <grub/dl.h>
+#include <grub/crypto.h>
+
+static grub_uint64_t crc64_table [256];
+
+static void
+init_crc64_table (void)
+{
+  auto grub_uint64_t reflect (grub_uint64_t ref, int len);
+  grub_uint64_t reflect (grub_uint64_t ref, int len)
+    {
+      grub_uint64_t result = 0;
+      int i;
+
+      for (i = 1; i <= len; i++)
+        {
+          if (ref & 1)
+            result |= 1ULL << (len - i);
+          ref >>= 1;
+        }
+
+      return result;
+    }
+
+  grub_uint64_t polynomial = 0x42f0e1eba9ea3693ULL;
+  int i, j;
+
+  for(i = 0; i < 256; i++)
+    {
+      crc64_table[i] = reflect(i, 8) << 56;
+      for (j = 0; j < 8; j++)
+	{
+	  crc64_table[i] = (crc64_table[i] << 1) ^
+            (crc64_table[i] & (1ULL << 63) ? polynomial : 0);
+	}
+      crc64_table[i] = reflect(crc64_table[i], 64);
+    }
+}
+
+static void
+crc64_init (void *context)
+{
+  if (! crc64_table[1])
+    init_crc64_table ();
+  *(grub_uint64_t *) context = 0;
+}
+
+static void
+crc64_write (void *context, const void *buf, grub_size_t size)
+{
+  unsigned i;
+  const grub_uint8_t *data = buf;
+  grub_uint64_t crc = ~grub_le_to_cpu64 (*(grub_uint64_t *) context);
+
+  for (i = 0; i < size; i++)
+    {
+      crc = (crc >> 8) ^ crc64_table[(crc & 0xFF) ^ *data];
+      data++;
+    }
+
+  *(grub_uint64_t *) context = grub_cpu_to_le64 (~crc);
+}
+
+static grub_uint8_t *
+crc64_read (void *context)
+{
+  return context;
+}
+
+static void
+crc64_final (void *context __attribute__ ((unused)))
+{
+}
+
+gcry_md_spec_t _gcry_digest_spec_crc64 =
+  {
+    "CRC64", 0, 0, 0, 8,
+    crc64_init, crc64_write, crc64_final, crc64_read,
+    sizeof (grub_uint64_t),
+    .blocksize = 64
+  };
+
+GRUB_MOD_INIT(crc64)
+{
+  grub_md_register (&_gcry_digest_spec_crc64);
+}
+
+GRUB_MOD_FINI(crc64)
+{
+  grub_md_unregister (&_gcry_digest_spec_crc64);
+}