-int select_crypto_if(int ifno);
-const char *crypto_init(int ifno);
-unsigned long encrypt(void *key, int keylen, void *pt, void *ct, int tlen);
-unsigned long decrypt(void *key, int keylen, void *ct, void *pt, int tlen);
-unsigned long hash(void *pt, int tlen, void *tag, int *taglen);
-unsigned long hmac(void *key, int keylen, void *pt, int tlen,
+int select_crypto_if(const int ifno);
+const char *crypto_init(const int ifno);
+unsigned long encrypt(const void *key, const int keylen, const void *pt, void *ct, const int tlen);
+unsigned long decrypt(const void *key, const int keylen, const void *ct, void *pt, const int tlen);
+unsigned long hash(const void *pt, const int tlen, void *tag, int *taglen);
+unsigned long hmac(const void *key, const int keylen, const void *pt, const int tlen,