-void MD2_Init(MD2_CTX *c);
-void MD2_Update(MD2_CTX *c, const unsigned char *data, unsigned long len);
-void MD2_Final(unsigned char *md, MD2_CTX *c);
-unsigned char *MD2(const unsigned char *d, unsigned long n,unsigned char *md);
+int MD2_Init(MD2_CTX *c);
+int MD2_Update(MD2_CTX *c, const unsigned char *data, size_t len);
+int MD2_Final(unsigned char *md, MD2_CTX *c);
+unsigned char *MD2(const unsigned char *d, size_t n,unsigned char *md);