Fix propotype to include the const qualifier

Reviewed-by: NAndy Polyakov <appro@openssl.org>
GH: #5582

doc/man3/EVP_EncryptInit.pod

@@ -59,33 +59,33 @@ EVP_enc_null
  void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx);
 
  int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-                        ENGINE *impl, unsigned char *key, unsigned char *iv);
+                        ENGINE *impl, const unsigned char *key, const unsigned char *iv);
  int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
                        int *outl, const unsigned char *in, int inl);
  int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl);
 
  int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-                        ENGINE *impl, unsigned char *key, unsigned char *iv);
+                        ENGINE *impl, const unsigned char *key, const unsigned char *iv);
  int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
                        int *outl, const unsigned char *in, int inl);
  int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *outm, int *outl);
 
  int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-                       ENGINE *impl, unsigned char *key, unsigned char *iv, int enc);
+                       ENGINE *impl, const unsigned char *key, const unsigned char *iv, int enc);
  int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
-                      int *outl, unsigned char *in, int inl);
+                      int *outl, const unsigned char *in, int inl);
  int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *outm, int *outl);
 
  int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-                     unsigned char *key, unsigned char *iv);
+                     const unsigned char *key, const unsigned char *iv);
  int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl);
 
  int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-                     unsigned char *key, unsigned char *iv);
+                     const unsigned char *key, const unsigned char *iv);
  int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm, int *outl);
 
  int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-                    unsigned char *key, unsigned char *iv, int enc);
+                    const unsigned char *key, const unsigned char *iv, int enc);
  int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm, int *outl);
 
  int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *x, int padding);