Obtain a random string for cryptographic use.
random-crypto obtains a random string of length <string length>. This statement uses a cryptographically secure pseudo random generator (CSPRNG) from OpenSSL library. If
"length" clause is omitted, the length is 20 by default. You can create <random string> with
"define" clause. <random string> is
allocated memory.
The value generated is always binary and may contain null-characters and is null-terminated.
Use this statement only when needed for specific cryptographic uses. In all other cases, use
random-string which is 2-3 times faster.