ctr_drbg: fix free uninitialized aes context
Application may enabled AES_ALT and define mbedtls_aes_context by its own.
The initial state of user-defined mbedtls_aes_context may not all byte zero.
In mbedtls_ctr_drbg_init, the code set all byte to zero, including the AES
context nested in the ctr_drbg context.
And in mbedtls_ctr_drbg_free, the code calls mbedtls_aes_free on an AES
context without calling mbedtls_aes_init.
If user-defined AES context requires an non-zero init, the mbedtls_aes_free
call in mbedtls_ctr_drbg_free is illegal.
This patch fix this issue by add mbedtls_aes_init in mbedtls_ctr_drbg_init.
So aes context will always be initialized to correct state.
Signed-off-by: kXuan <kxuanobj@gmail.com>
diff --git a/library/ctr_drbg.c b/library/ctr_drbg.c
index 43f490e..75103a3 100644
--- a/library/ctr_drbg.c
+++ b/library/ctr_drbg.c
@@ -51,6 +51,7 @@
void mbedtls_ctr_drbg_init( mbedtls_ctr_drbg_context *ctx )
{
memset( ctx, 0, sizeof( mbedtls_ctr_drbg_context ) );
+ mbedtls_aes_init( &ctx->aes_ctx );
/* Indicate that the entropy nonce length is not set explicitly.
* See mbedtls_ctr_drbg_set_nonce_len(). */
ctx->reseed_counter = -1;