Fix copypasta in the description of mbedtls_gcm_update_ad
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/mbedtls/gcm.h b/include/mbedtls/gcm.h
index 7218081..78f2a43 100644
--- a/include/mbedtls/gcm.h
+++ b/include/mbedtls/gcm.h
@@ -240,8 +240,9 @@
size_t iv_len );
/**
- * \brief This function starts a GCM encryption or decryption
- * operation.
+ * \brief This function feeds an input buffer as associated data
+ * (authenticated but not encrypted data) in a GCM
+ * encryption or decryption operation.
*
* \note This function may only be called once per operation:
* you must pass the whole associated data in a single