CTR_DRBG: add the possibility of grabbing entropy for a nonce
Add a new function mbedtls_ctr_drbg_set_nonce_len() which configures
the DRBG instance to call f_entropy a second time during the initial
seeding to grab a nonce.
The default nonce length is 0, so there is no behavior change unless
the user calls the new function.
diff --git a/library/ctr_drbg.c b/library/ctr_drbg.c
index 85bd04f..8a62f6d 100644
--- a/library/ctr_drbg.c
+++ b/library/ctr_drbg.c
@@ -357,10 +357,10 @@
* and with output
* ctx contains new_working_state
*/
-int mbedtls_ctr_drbg_reseed_internal( mbedtls_ctr_drbg_context *ctx,
- const unsigned char *additional,
- size_t len,
- size_t nonce_len )
+static int mbedtls_ctr_drbg_reseed_internal( mbedtls_ctr_drbg_context *ctx,
+ const unsigned char *additional,
+ size_t len,
+ size_t nonce_len )
{
unsigned char seed[MBEDTLS_CTR_DRBG_MAX_SEED_INPUT];
size_t seedlen = 0;