Security-57031.1.35.tar.gz

[apple/security.git] / Security / authd / crc.h

diff --git a/Security/authd/crc.h b/Security/authd/crc.h
new file mode 100644 (file)
index 0000000..8518438
--- /dev/null
+++ b/Security/authd/crc.h
@@ -0,0 +1,53 @@
+/* Copyright (c) 2012 Apple Inc. All Rights Reserved. */
+
+#ifndef _SECURITY_AUTH_CRC_H_
+#define _SECURITY_AUTH_CRC_H_
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+extern const uint64_t _crc_table64[256];
+extern const uint64_t xorout;
+    
+AUTH_INLINE uint64_t
+crc64_init()
+{
+    return xorout;
+}
+
+AUTH_INLINE uint64_t
+crc64_final(uint64_t crc)
+{
+      return crc ^= xorout;
+}
+    
+AUTH_INLINE AUTH_NONNULL_ALL uint64_t
+crc64_update(uint64_t crc, const void *buf, uint64_t len)
+{
+    const unsigned char * ptr = (const unsigned char *) buf;
+
+    while (len-- > 0) {
+        crc = _crc_table64[((crc >> 56) ^ *(ptr++)) & 0xff] ^ (crc << 8);
+    }
+    
+    return crc;
+}
+
+AUTH_INLINE uint64_t
+crc64(const void *buf, uint64_t len)
+{
+    uint64_t crc = crc64_init();
+    
+    crc = crc64_update(crc, buf, len);
+    
+    crc = crc64_final(crc);
+    
+    return crc;
+}
+    
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* !_SECURITY_AUTH_CRC_H_ */