+ The resulting hash value is written to \a OUT as a NUL terminated
+ string of numbers in two-digit hexadecimal ASCII representation.
+
+ Exactly \a OUT_LEN bytes are written to \a OUT, based on the first
+ (\a OUT_LEN - 1) / 2 bytes of the hash. Note that in the case when
+ \OUT_LEN - 1 is more than two times the length of the hash, the
+ output is repeated by concatinating another hex ASCII
+ representation of the hash to the output until the buffer is full.
+