/// <summary>
/// Generates a shared access signature that can be used to authenticate with a topic.
/// The signature can be used as the input to the <see cref="AzureSasCredential(string)"/> constructor.
/// This credential can then be passed to the <see cref="EventGridPublisherClient(Uri, AzureSasCredential, EventGridPublisherClientOptions)"/> constructor.
/// </summary>
/// <param name="key">The <see cref="AzureKeyCredential"/> to use to authenticate with the service
/// when generating the shared access signature.</param>
/// <returns>A shared access signature that can be used to authenticate with an Event Grid topic.</returns>
public string GenerateSas(AzureKeyCredential key)
{
Argument.AssertNotNull(key, nameof(key));
const char Resource = 'r';
const char Expiration = 'e';
const char Signature = 's';
var uriBuilder = new RequestUriBuilder();
uriBuilder.Reset(Endpoint);
uriBuilder.AppendQuery("api-version", ApiVersion.GetVersionString(), true);
string encodedResource = HttpUtility.UrlEncode(uriBuilder.ToString());
var encodedExpirationUtc = HttpUtility.UrlEncode(ExpiresOn.ToString(CultureInfo.CreateSpecificCulture("en-US")));
string unsignedSas = $"{Resource}={encodedResource}&{Expiration}={encodedExpirationUtc}";
using (var hmac = new HMACSHA256(Convert.FromBase64String(key.Key)))
{
string signature = Convert.ToBase64String(hmac.ComputeHash(Encoding.UTF8.GetBytes(unsignedSas)));
string encodedSignature = HttpUtility.UrlEncode(signature);
string signedSas = $"{unsignedSas}&{Signature}={encodedSignature}";
return(signedSas);
}
}
/// <summary>
/// To the JWT dictionary.
/// </summary>
/// <returns></returns>
public Dictionary <string, object> ToJwtDictionary()
{
return(new Dictionary <string, object>()
{
{ "userId", UserId.ToString() },
{ "initOn", InitOn.ToString("yyyyMMddHHmmss") },
{ "expiresOn", ExpiresOn.ToString("yyyyMMddHHmmss") }
});
}
/// <summary>
/// Builds up the UserDelegationKey portion of the SAS query parameter string.
/// </summary>
public void AppendProperties(StringBuilder stringBuilder)
{
if (!string.IsNullOrWhiteSpace(ObjectId))
{
stringBuilder.AppendQueryParameter(Constants.Sas.Parameters.KeyObjectId, ObjectId);
}
if (!string.IsNullOrWhiteSpace(TenantId))
{
stringBuilder.AppendQueryParameter(Constants.Sas.Parameters.KeyTenantId, TenantId);
}
if (StartsOn != DateTimeOffset.MinValue)
{
stringBuilder.AppendQueryParameter(Constants.Sas.Parameters.KeyStart, WebUtility.UrlEncode(StartsOn.ToString(Constants.SasTimeFormatSeconds, CultureInfo.InvariantCulture)));
}
if (ExpiresOn != DateTimeOffset.MinValue)
{
stringBuilder.AppendQueryParameter(Constants.Sas.Parameters.KeyExpiry, WebUtility.UrlEncode(ExpiresOn.ToString(Constants.SasTimeFormatSeconds, CultureInfo.InvariantCulture)));
}
if (!string.IsNullOrWhiteSpace(Service))
{
stringBuilder.AppendQueryParameter(Constants.Sas.Parameters.KeyService, Service);
}
if (!string.IsNullOrWhiteSpace(Version))
{
stringBuilder.AppendQueryParameter(Constants.Sas.Parameters.KeyVersion, Version);
}
}