public static bool IsReplayRequest(IMemoryCache memoryCache, HmacAuthenticationOptions options, string nonce, string requestUnixTimeStamp)
{
var nonceInMemory = memoryCache.Get(nonce);
if (nonceInMemory != null)
{
return(true);
}
var requestTime = DateTimeOffset.FromUnixTimeSeconds(Convert.ToInt64(requestUnixTimeStamp));
var now = DateTimeOffset.UtcNow;
if (now - requestTime > options.MaxRequestAge)
{
return(true);
}
memoryCache.Set(nonce, default(bool), now + options.MaxRequestAge);
return(false);
}
static async Task <bool> ValidateContentAsync(HttpRequest request, string appId, string requestSignatureHash, string nonce, string requestTimeStamp, HmacAuthenticationOptions options, IMemoryCache memoryCache, Lazy <byte[]> secretKeyBytes)
{
if (options.AppId != appId)
{
return(false);
}
if (ReplayRequestBouncer.IsReplayRequest(memoryCache, options, nonce, requestTimeStamp))
{
return(false);
}
var content = await GetRequestBodyMd5(request).ConfigureAwait(false);
var data = HmacHasher.GetDataToHash(request, appId, nonce, requestTimeStamp, content);
var signatureHash = data.ToUtf8Bytes()
.ToBase64HmacSha256Hash(secretKeyBytes.Value);
return(requestSignatureHash.Equals(signatureHash, StringComparison.Ordinal));
}
public static Task <bool> ValidateAsync(HttpRequest request, string authorization, HmacAuthenticationOptions options, IMemoryCache memoryCache, Lazy <byte[]> secretKeyBytes)
{
var authenticationHeader = AuthenticationHeaderValue.Parse(authorization);
if (!authenticationHeader.Scheme.EqualsInsensitiveCase(HmacAuthenticationHandler.SchemeName))
{
return(Task.FromResult(false));
}
var parameters = authenticationHeader.Parameter.Split(':');
if (parameters.Length != 4)
{
return(Task.FromResult(false));
}
var appId = parameters[0];
var signatureHash = parameters[1];
var nonce = parameters[2];
var requestTimeStamp = parameters[3];
return(ValidateContentAsync(request, appId, signatureHash, nonce, requestTimeStamp, options, memoryCache, secretKeyBytes));
}