There's a name clash between OpenSSL and RSAref. Since this engine handles

RSAref data, pretend we don't care for OpenSSL's MD2 and MD5 structures or
implementation.
Remove all kinds of silly warning

demos/engines/rsaref/rsaref.c

@@ -3,11 +3,14 @@
    be found a little here and there. */
 
 #include <stdio.h>
+#include <string.h>
 #include "./source/global.h"
 #include "./source/rsaref.h"
 #include "./source/rsa.h"
 #include "./source/des.h"
 #include <openssl/err.h>
+#define OPENSSL_NO_MD2
+#define OPENSSL_NO_MD5
 #include <openssl/evp.h>
 #include <openssl/bn.h>
 #include <openssl/engine.h>
@@ -400,7 +403,7 @@ static int rsaref_private_decrypt(int len, const unsigned char *from, unsigned c
 
 	if (!RSAref_Private_eay2ref(rsa,&RSAkey))
 		goto err;
-	if ((i=RSAPrivateDecrypt(to,&outlen,(unsigned char *)from,len,&RSAkey)) != 0)
+	if ((i=RSAPrivateDecrypt(to,&(unsigned int)outlen,(unsigned char *)from,len,&RSAkey)) != 0)
 		{
 		RSAREFerr(RSAREF_F_RSAREF_PRIVATE_DECRYPT,i);
 		outlen= -1;
@@ -423,7 +426,7 @@ static int rsaref_private_encrypt(int len, const unsigned char *from, unsigned c
 	}
 	if (!RSAref_Private_eay2ref(rsa,&RSAkey))
 		goto err;
-	if ((i=RSAPrivateEncrypt(to,&outlen,(unsigned char *)from,len,&RSAkey)) != 0)
+	if ((i=RSAPrivateEncrypt(to,&(unsigned int)outlen,(unsigned char *)from,len,&RSAkey)) != 0)
 		{
 		RSAREFerr(RSAREF_F_RSAREF_PRIVATE_ENCRYPT,i);
 		outlen= -1;
@@ -441,7 +444,7 @@ static int rsaref_public_decrypt(int len, const unsigned char *from, unsigned ch
 
 	if (!RSAref_Public_eay2ref(rsa,&RSAkey))
 		goto err;
-	if ((i=RSAPublicDecrypt(to,&outlen,(unsigned char *)from,len,&RSAkey)) != 0)
+	if ((i=RSAPublicDecrypt(to,&(unsigned int)outlen,(unsigned char *)from,len,&RSAkey)) != 0)
 		{
 		RSAREFerr(RSAREF_F_RSAREF_PUBLIC_DECRYPT,i);
 		outlen= -1;
@@ -478,7 +481,7 @@ static int rsaref_public_encrypt(int len, const unsigned char *from, unsigned ch
 
 	if (!RSAref_Public_eay2ref(rsa,&RSAkey))
 		goto err;
-	if ((i=RSAPublicEncrypt(to,&outlen,(unsigned char *)from,len,&RSAkey,&rnd)) != 0)
+	if ((i=RSAPublicEncrypt(to,&(unsigned int)outlen,(unsigned char *)from,len,&RSAkey,&rnd)) != 0)
 		{
 		RSAREFerr(RSAREF_F_RSAREF_PUBLIC_ENCRYPT,i);
 		outlen= -1;