Strictly not for use in statistical analysis. Non-reproducible and with
unknown statistical properties. Provides an alternative source of
randomness from the Mbed TLS library for purposes such as cryptographic
key generation. Mbed TLS uses a block-cipher in counter mode operation,
as defined in NIST SP800-90A: *Recommendation for Random Number
Generation Using Deterministic Random Bit Generators*. The implementation
uses AES-256 as the underlying block cipher, with a derivation function,
and an entropy collector combining entropy from multiple sources
including at least one strong entropy source.

## Value

A length ‘n’ raw vector, or length one vector of ‘2n’ random characters, depending on the value of ‘convert’ supplied.

## Details

If ‘n’ is non-integer, it will be coerced to integer; if a vector, only the first element will be used.