docs: Update docs with firmware encryption feature
Update documentation with optional firmware encryption feature.
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Change-Id: I26691b18e1ee52a73090954260f26f2865c4e05a
diff --git a/docs/design/auth-framework.rst b/docs/design/auth-framework.rst
index ae77391..1a53e22 100644
--- a/docs/design/auth-framework.rst
+++ b/docs/design/auth-framework.rst
@@ -934,7 +934,7 @@
based on mbed TLS, which can be found in
``drivers/auth/mbedtls/mbedtls_crypto.c``. This library is registered in the
authentication framework using the macro ``REGISTER_CRYPTO_LIB()`` and exports
-three functions:
+four functions:
.. code:: c
@@ -945,6 +945,11 @@
void *pk_ptr, unsigned int pk_len);
int verify_hash(void *data_ptr, unsigned int data_len,
void *digest_info_ptr, unsigned int digest_info_len);
+ int auth_decrypt(enum crypto_dec_algo dec_algo, void *data_ptr,
+ size_t len, const void *key, unsigned int key_len,
+ unsigned int key_flags, const void *iv,
+ unsigned int iv_len, const void *tag,
+ unsigned int tag_len)
The mbedTLS library algorithm support is configured by both the
``TF_MBEDTLS_KEY_ALG`` and ``TF_MBEDTLS_KEY_SIZE`` variables.
@@ -957,6 +962,9 @@
- ``TF_MBEDTLS_KEY_SIZE`` sets the supported RSA key size for TFA. Valid values
include 1024, 2048, 3072 and 4096.
+- ``TF_MBEDTLS_USE_AES_GCM`` enables the authenticated decryption support based
+ on AES-GCM algorithm. Valid values are 0 and 1.
+
.. note::
If code size is a concern, the build option ``MBEDTLS_SHA256_SMALLER`` can
be defined in the platform Makefile. It will make mbed TLS use an