public int GetCode(HashAlgorithmType hashAlgorithm, byte[] secret, byte numberOfDigits, byte periodInSeconds)
{
//https://tools.ietf.org/html/rfc4226#section-5.4
//https://tools.ietf.org/html/rfc6238#section-4.2
secret.CheckArgumentNullOrEmpty(nameof(secret));
if (numberOfDigits < 6 || numberOfDigits > 8)
{
throw new ArgumentException(Resources.Exception_InvalidNumberOfDigits);
}
if (periodInSeconds < 30)
{
throw new ArgumentException(Resources.Exception_InvalidPeriodInSeconds);
}
var deltaTime = _systemTime.GetUtcNow() - UnixEpoch;
var counter = ConvertToBytes((ulong)(deltaTime.TotalSeconds / periodInSeconds));
byte[] hash;
using (var hmacAlgorithm = GetHmac(hashAlgorithm))
{
hmacAlgorithm.Key = secret;
hash = hmacAlgorithm.ComputeHash(counter);
}
int offset = hash[hash.Length - 1] & 0xf;
int code = (hash[offset] & 0x7f) << 24
| (hash[offset + 1] & 0xff) << 16
| (hash[offset + 2] & 0xff) << 8
| (hash[offset + 3] & 0xff);
return(code % TenPow[numberOfDigits]);
}
private static ICollection <KeyValuePair <string, string> > GetHmacSha1Parameters(string consumerToken, INonceCreator nonceCreator, ISystemTime systemTime, Dictionary <string, string?>?additionalParameters = null) => GetHmacSha1Parameters(consumerToken, nonceCreator.CreateNonce(), DateTimeUtility.ToUnixTimestamp(systemTime.GetUtcNow()).ToInvariantString(), additionalParameters);
public Customer RegisterCustomer(string name)
{
return(new Customer(_idGenerator.NewId(), _systemTime.GetUtcNow(), name));
}