public ITOTPResult GetCodes(string hashAlgorithm, byte[] key, TOTPOptions options = null)
{
if (!this.hashAlgorithms.TryGetValue(hashAlgorithm, out var hashAlgorithmProvider))
{
throw new AlgorithmNotFoundException(hashAlgorithm);
}
if (key is null)
{
throw new ArgumentNullException(nameof(key));
}
if (options is null)
{
options = TOTPOptions.Default;
}
using var hmac = hashAlgorithmProvider.GetHash(key);
var secondsSinceEpoch = (ulong)(this.systemClock.UtcNow - unixEpoch).TotalSeconds;
var validFor = 30 - (secondsSinceEpoch % (uint)options.Period);
var timePeriod = secondsSinceEpoch / (uint)options.Period;
var currentCode = this.GetOneCode(hmac, timePeriod, options.Digits);
var previousCodes = Enumerable.Range(0, options.PriorPeriods)
.Select(x => this.GetOneCode(hmac, timePeriod - (ulong)x - 1, options.Digits));
var followingCodes = Enumerable.Range(0, options.FollowingPeriods)
.Select(x => this.GetOneCode(hmac, timePeriod + (ulong)x + 1, options.Digits));
return(new TOTPResult(currentCode, TimeSpan.FromSeconds(validFor), previousCodes, followingCodes));
}
public void TestsFromRFC6238(string dateTime, string key, string code, string algorithm)
{
var totpOptions = new TOTPOptions(digits: 8);
var totpProvider = new ServiceCollection()
.AddTOTP()
.AddSingleton <ISystemClock>(new ExplicitSystemClock(dateTime))
.BuildServiceProvider()
.GetRequiredService <ITOTPProvider>();
var result = totpProvider.GetCodes(algorithm, key, totpOptions);
Assert.Equal(code, result.CurrentCode);
}
public ITOTPResult GetCodes(string hashAlgorithm, string key, TOTPOptions options = null) => this.GetCodes(hashAlgorithm, Base32.Decode(key), options);
