public void ReturnsTrueForCloseEnoughTimestamps(DateTimeOffset now)
{
var path = "/ls";
var plaintext = $"{now:O}{path}";
var key = new byte[64];
System.Security.Cryptography.RandomNumberGenerator.Create().GetNonZeroBytes(key);
var hmac = HMAC.Create(AlgorithmName);
hmac.Key = key;
var hash = hmac.ComputeHash(Encoding.UTF8.GetBytes(plaintext));
var target = new HmacVerification(AlgorithmName, Convert.ToBase64String(key), 60);
Assert.True(target.Verify(now.ToString("O"), path, Convert.ToBase64String(hash)));
}
public void ReturnsFalseForInvalidHash()
{
var now = DateTimeOffset.UtcNow;
var path = "/ls";
var plaintext = $"{now:O}{path}";
var key = new byte[64];
System.Security.Cryptography.RandomNumberGenerator.Create().GetNonZeroBytes(key);
var hmac = HMAC.Create(AlgorithmName);
hmac.Key = key;
var hash = hmac.ComputeHash(Encoding.UTF8.GetBytes(plaintext));
hash[0] = (byte)(hash[0] > 0 ? hash[0] - (byte)1 : (byte)255);
var target = new HmacVerification(AlgorithmName, Convert.ToBase64String(key), 60);
Assert.False(target.Verify(now.ToString("O"), path, Convert.ToBase64String(hash)));
}
