new file mode 100644
--- /dev/null
+++ b/src/core/ngx_crc32.h
@@ -0,0 +1,33 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#ifndef _NGX_CRC32_H_INCLUDED_
+#define _NGX_CRC32_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+extern uint32_t  ngx_crc32_table[];
+
+
+static ngx_inline uint32_t
+ngx_crc32(u_char *p, size_t len)
+{
+    uint32_t  crc;
+
+    crc = 0xffffffff;
+
+    while (len--) {
+        crc = ngx_crc32_table[(crc ^ *p++) & 0xff] ^ (crc >> 8);
+    }
+
+    return crc ^ 0xffffffff;
+}
+
+
+#endif /* _NGX_CRC32_H_INCLUDED_ */