Better wording around passing NULL to mbedtls_zeroize_and_free()
Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
diff --git a/library/common.h b/library/common.h
index ce92238..b68089e 100644
--- a/library/common.h
+++ b/library/common.h
@@ -117,11 +117,13 @@
/**
* \brief Securely zeroize a buffer then free it.
*
- * Exactly the same as consecutive calls to
- * \c mbedtls_platform_zeroize() and \c mbedtls_free(), but has a
+ * Similar to making consecutive calls to
+ * \c mbedtls_platform_zeroize() and \c mbedtls_free(), but has
* code size savings, and potential for optimisation in the future.
*
- * \param buf Buffer to be zeroized then freed. May be \c NULL.
+ * Guaranteed to be a no-op if \p buf is \c NULL and \p len is 0.
+ *
+ * \param buf Buffer to be zeroized then freed.
* \param len Length of the buffer in bytes
*/
void mbedtls_zeroize_and_free(void *buf, size_t len);