-static void null_init_key(EVP_CIPHER_CTX *ctx, unsigned char *key,
- unsigned char *iv,int enc);
-static void null_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
- unsigned char *in, unsigned int inl);
-static EVP_CIPHER n_cipher=
+static int null_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
+ const unsigned char *iv,int enc);
+static int null_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
+ const unsigned char *in, unsigned int inl);
+static const EVP_CIPHER n_cipher=