Switch the DRBGs from AES-128-CTR to AES-256-CTR
GH:
/*
* Default security strength (in the sense of [NIST SP 800-90Ar1])
- * of the default OpenSSL DRBG, and the corresponding NID.
*
- * Currently supported values: 128, 192, 256
+ * NIST SP 800-90Ar1 supports the strength of the DRBG being smaller than that
+ * of the cipher by collecting less entropy. The current DRBG implemantion does
+ * not take RAND_DRBG_STRENGTH into account and sets the strength of the DRBG
+ * to that of the cipher.
*
- * TODO(DRBG): would be nice to have the strength configurable
+ * RAND_DRBG_STRENGTH is currently only used for the legacy RAND
+ * implementation.
+ *
+ * Currently supported ciphers are: NID_aes_128_ctr, NID_aes_192_ctr and
+ * NID_aes_256_ctr
+ *
+ * TODO(DRBG): would be nice to have the NID and strength configurable
*/
-# define RAND_DRBG_STRENGTH 128
-# define RAND_DRBG_NID NID_aes_128_ctr
+# define RAND_DRBG_STRENGTH 256
+# define RAND_DRBG_NID NID_aes_256_ctr
/*
* Object lifetime functions.
