public async Task <TokenExchangeResult> ExchangeTokenAsync(string referenceToken, ReferenceTokenExchangeOptions options)
{
_logger.LogInformation("Checking cache for the presence of token");
var cachedToken = _cache.FindToken(referenceToken);
if (cachedToken == null)
{
_logger.LogInformation("Token not found in cache");
var tokenResult = await PerformOnlineTokenExchange(referenceToken, options);
AddTokenToCache(tokenResult);
return(tokenResult);
}
if (cachedToken.AccessTokenExpiryTime < DateTimeOffset.UtcNow)
{
_logger.LogInformation("Expired token found in cache");
_cache.RemoveToken(cachedToken);
var tokenResult = await PerformOnlineTokenExchange(referenceToken, options);
AddTokenToCache(tokenResult);
return(tokenResult);
}
_logger.LogInformation("Token found in cache, returning token");
return(cachedToken);
}
private async Task <TokenExchangeResult> PerformOnlineTokenExchange(string referenceToken, ReferenceTokenExchangeOptions options)
{
return(await _tokenExchangeService.ExchangeTokenAsync(referenceToken, options));
}
public async Task <TokenExchangeResult> ExchangeTokenAsync(string referenceToken, ReferenceTokenExchangeOptions options)
{
if (referenceToken == null)
{
referenceToken = string.Empty;
}
var payload = new
{
token = referenceToken
};
var identityServer = await DiscoverIdentityServerAsync(options.IdentityServerRootUrl, options.RequireHttpsEndpoints, options.AdditionalEndpointBaseAddresses);
var client = new TokenClient(identityServer.TokenEndpoint, options.ClientId, options.ClientSecret, options.HttpHandler);
_logger.LogInformation($"Requesting token exchange from Identity Server: {identityServer.TokenEndpoint}");
var tokenResponse = await client.RequestCustomGrantAsync(options.GrantType, options.Scope, payload);
if (tokenResponse.IsError)
{
_logger.LogWarning($"An error occured during reference token exchange: {tokenResponse.Error}");
}
var result = new TokenExchangeResult
{
ReferenceToken = referenceToken,
AccessToken = tokenResponse.AccessToken,
AccessTokenExpiryTime = DateTimeOffset.UtcNow.AddSeconds(tokenResponse.ExpiresIn)
};
_logger.LogInformation("Token exchange with Identity Server completed successfully");
return(result);
}
