AES: add macro of MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH
Add configuration option to support 128-bit key length only
in AES calculation.
Signed-off-by: Yanray Wang <yanray.wang@arm.com>
diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index 6158850..8acc377 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -523,6 +523,25 @@
//#define MBEDTLS_AES_FEWER_TABLES
/**
+ * \def MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH
+ *
+ * Use only 128-bit keys in AES operations to save ROM.
+ *
+ * Uncommenting this macro removes support for AES operations that are using 192
+ * or 256-bit keys.
+ *
+ * Tradeoff: Uncommenting this macro reduces ROM footprint by ~1116 bytes.
+ *
+ * If uncommented, uncomment also MBEDTLS_CTR_DRBG_USE_128_BIT_KEY
+ *
+ * Module: library/aes.c
+ *
+ * Requires: MBEDTLS_AES_C
+ *
+ */
+//#define MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH
+
+/**
* \def MBEDTLS_CAMELLIA_SMALL_MEMORY
*
* Use less ROM for the Camellia implementation (saves about 768 bytes).