public static BigInteger Random(this Random generator, BigInteger limit) {
ContractUtils.Requires(limit.Sign >= 0, "limit");
ContractUtils.RequiresNotNull(generator, "generator");
// TODO: this doesn't yield a uniform distribution (small numbers will be picked more frequently):
byte[] bytes = new byte[limit.GetByteCount() + 1];
generator.NextBytes(bytes);
bytes[bytes.Length - 1] = 0;
return new BigInteger(new BigInt(bytes)) % limit;
}
