Add an md5 library derived from a public domain implementation for dwarf4

type signature computation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182348 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/MD5.h

@@ -0,0 +1,59 @@
+/*
+ * This code is derived from (original license follows):
+ *
+ * This is an OpenSSL-compatible implementation of the RSA Data Security, Inc.
+ * MD5 Message-Digest Algorithm (RFC 1321).
+ *
+ * Homepage:
+ * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5
+ *
+ * Author:
+ * Alexander Peslyak, better known as Solar Designer <solar at openwall.com>
+ *
+ * This software was written by Alexander Peslyak in 2001.  No copyright is
+ * claimed, and the software is hereby placed in the public domain.
+ * In case this attempt to disclaim copyright and place the software in the
+ * public domain is deemed null and void, then the software is
+ * Copyright (c) 2001 Alexander Peslyak and it is hereby released to the
+ * general public under the following terms:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted.
+ *
+ * There's ABSOLUTELY NO WARRANTY, express or implied.
+ *
+ * See md5.c for more information.
+ */
+
+#ifndef LLVM_SYSTEM_MD5_H
+#define LLVM_SYSTEM_MD5_H
+
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+
+class MD5 {
+  // Any 32-bit or wider unsigned integer data type will do.
+  typedef uint32_t MD5_u32plus;
+
+  MD5_u32plus a, b, c, d;
+  MD5_u32plus hi, lo;
+  unsigned char buffer[64];
+  MD5_u32plus block[16];
+
+ public:
+  MD5();
+
+  /// \brief Updates the hash for arguments provided.
+  void Update(void *data, unsigned long size);
+
+  /// \brief Finishes off the hash and puts the result in result.
+  void Final(unsigned char *result);
+
+private:
+  void *body(void *data, unsigned long size);
+};
+
+}
+
+#endif