Prototypes for symmetric cipher functions
diff --git a/include/psa/crypto_struct.h b/include/psa/crypto_struct.h
index 6bd4ed2..ffa835e 100644
--- a/include/psa/crypto_struct.h
+++ b/include/psa/crypto_struct.h
@@ -93,4 +93,16 @@
     } ctx;
 };
 
+struct psa_cipher_operation_s
+{
+    psa_algorithm_t alg;
+    int key_set : 1;
+    int iv_set : 1;
+    uint8_t iv_size;
+    uint8_t block_size;
+    union
+    {
+    } ctx;
+};
+
 #endif /* PSA_CRYPTO_STRUCT_H */