Ensure libmd symbols do not clash with libcrypto

Add a prefix to all symbols in libmd to avoid incompatibilites
with same-named, but not binary compatible, symbols from libcrypto.

Also introduce Weak aliases to avoid the need to rebuild dependent
binaries and a major version bump.

PR:		199119
Differential Revision:	D2216
Reviewed by:	roberto, delphij
MFC after:	2 weeks

1 files changed, 12 insertions, 1 deletions

diff --git a/lib/libmd/md5c.c b/lib/libmd/md5c.c
index d097390..bfbb531 100644
--- a/lib/libmd/md5c.c
+++ b/lib/libmd/md5c.c
@@ -39,7 +39,7 @@ __FBSDID("$FreeBSD$");
 
 #include <machine/endian.h>
 #include <sys/endian.h>
-#include <sys/md5.h>
+#include "md5.h"
 
 static void MD5Transform(u_int32_t [4], const unsigned char [64]);
 
@@ -335,3 +335,14 @@ MD5Transform (state, block)
 	/* Zeroize sensitive information. */
 	memset ((void *)x, 0, sizeof (x));
 }
+
+#undef MD5Init
+__weak_reference(_libmd_MD5Init, MD5Init);
+#undef MD5Update
+__weak_reference(_libmd_MD5Update, MD5Update);
+#undef MD5Pad
+__weak_reference(_libmd_MD5Pad, MD5Pad);
+#undef MD5Final
+__weak_reference(_libmd_MD5Final, MD5Final);
+#undef MD5Transform
+__weak_reference(_libmd_MD5Transform, MD5Transform);