4.1.1 Public: SeedGenerator

Parent: 4.1 Utility namespace · Guide map

SeedGenerator offers a local clock seed and an optional seed from Random.org's HTTPS integer service. Both return a long that you can pass to a seeded constructor.

Local clock seed

using RandEXom.RandomLib;
using RandEXom.Utility;

long seed = SeedGenerator.GetJoinedCurrentDate();
var random = new ModuloRandom(seed);

GetJoinedCurrentDate() concatenates parts of the local current date and time (milliseconds, seconds, minutes, hours, day, month, and two-digit year). It does not pad fields, so different timestamps can form the same digits. This method does not promise a unique or cryptographically secure seed. Use a fixed seed for reproducible tests.

Random.org seed

using RandEXom.RandomLib;
using RandEXom.Utility;

long seed = await SeedGenerator.GetRandomOrgSeedAsync();
var random = new ModuloRandom(seed);

GetRandomOrgSeedAsync() makes one HTTPS request for two new independent integers in [0, 999999999], then combines them as first * 1_000_000_000 + second. The result is nonnegative and below 1_000_000_000_000_000_000, so it fits in a long. It is a seed for your local generator, not a stream of Random.org results. This method uses Random.org's keyless HTTP integer interface; no API key is required. It does not use the separate JSON-RPC API, which requires a key.

The request is asynchronous and accepts an optional CancellationToken. The default HTTP client has a three-minute timeout, and requests made through this helper are serialized so it does not send parallel calls. Network, HTTP, quota, cancellation, and invalid-response failures are propagated; the helper does not substitute a local seed. Random.org's automated-client guidelines recommend infrequent requests, a generous timeout, quota awareness, and a contact email in the User-Agent for regular automated use. For frequent use, generate one seed and reuse a local random source, or use an appropriate Random.org API client. The default client identifies this project by its repository URL.

If you need a configured client or want to test without using Random.org's quota, use the overload:

using System.Net.Http;
using RandEXom.Utility;

using var client = new HttpClient { Timeout = TimeSpan.FromMinutes(3) };
client.DefaultRequestHeaders.UserAgent.ParseAdd("MyApp/1.0 (contact@example.com)");
long seed = await SeedGenerator.GetRandomOrgSeedAsync(client);

You own and dispose a supplied client. For tests, supply a client with a fake HttpMessageHandler; the project's Verification uses this approach and makes no live Random.org request. A Random.org seed is not reproducible unless you save its returned value. It does not make RandEXom's random generators cryptographically secure.

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