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-rw-r--r--grub-core/lib/crc64.c114
1 files changed, 114 insertions, 0 deletions
diff --git a/grub-core/lib/crc64.c b/grub-core/lib/crc64.c
new file mode 100644
index 0000000..4960f3f
--- /dev/null
+++ b/grub-core/lib/crc64.c
@@ -0,0 +1,114 @@
+/* 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>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+static grub_uint64_t crc64_table [256];
+
+/* Helper for init_crc64_table. */
+static 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;
+}
+
+static void
+init_crc64_table (void)
+{
+ 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);
+}