Rename symbol current to current_cdi (#81)

Rename current to current_cdi, because it clashes with the Linux Kernel
macro `current`.

Author: werwurm

include/nat20/functionality.h

@@ -179,14 +179,14 @@ extern n20_error_t n20_derive_key(n20_crypto_context_t *crypto_ctx,
  * returned in the given buffer.
  *
  * @param crypto_ctx The crypto context.
- * @param current The current CDI secret to derive the key from.
+ * @param current_cdi The current CDI secret to derive the key from.
  * @param next The derived key.
  * @param info The information to use for the derivation.
  *
  * @return n20_error_ok_e on success, or an error code on failure.
  */
 extern n20_error_t n20_next_level_cdi_attest(n20_crypto_context_t *crypto_ctx,
-                                             n20_crypto_key_t current,
+                                             n20_crypto_key_t current_cdi,
                                              n20_crypto_key_t *next,
                                              n20_compressed_input_t info);
 

src/core/functionality.c

@@ -202,12 +202,12 @@ n20_error_t n20_derive_key(n20_crypto_context_t *crypto_ctx,
 }
 
 n20_error_t n20_next_level_cdi_attest(n20_crypto_context_t *crypto_ctx,
-                                      n20_crypto_key_t current,
+                                      n20_crypto_key_t current_cdi,
                                       n20_crypto_key_t *next,
                                       n20_compressed_input_t info) {
 
     return n20_derive_key(crypto_ctx,
-                          current,
+                          current_cdi,
                           next,
                           n20_crypto_key_type_cdi_e,
                           (n20_slice_t){.size = N20_FUNC_COMPRESSED_INPUT_SIZE, .buffer = &info[0]},