Yes and no! The default config value for **CTR_DRBG_ENTROPY_LEN** is made based on what we know about entropy from config.h. We want to provide decent defaults for basic use. But a user that does not use our entropy module can provide a different value for **CTR_DRBG_ENTROPY_LEN** for their own Entropy module. 

**POLARSSL_ENTROPY_SHA512_ACCUMULATOR** and **POLARSSL_ENTROPY_SHA256_ACCUMULATOR** are both only defined from *entropy.h*, not *config.h*, so if we don't use the entropy.h the 'weakest' value is used instead of the strongest one..