The CBC-MAC mode (as described in section 3.1.5.1.1 and Appendix F in NIST Special Publication 800-90) of AES128 has been used as FIPS-approved keyed conditioning function. The conditioning function takes CONTROL.NB128BITBLOCKS x 128 bits from the entropy source as input and generates 128 bits as output. Assuming a min-entropy of 50% and NB128BITBLOCKS = 4, the input entropy is hin=512 x 50%=256 bits. According to section 3.1.5.1.2 in NIST Special Publication 800-90, the output of the conditioning function can be considered to have 128 bits of full entropy. The conditioning function can be tested by sending known data (using TESTDATA with CONTROL.TESTEN=1).