/// <summary>
/// Gets cert, signs jwt token and generates an installation token for msgraph installation instance
/// </summary>
/// <returns>installation token</returns>
internal async Task <string> GetGithubAppToken()
{
if (!string.IsNullOrEmpty(_configuration[Constants.GitHubToken]))
{
return(_configuration[Constants.GitHubToken]);
}
if (_cache.TryGetValue(Constants.GitHubToken, out string token))
{
return(token);
}
var KeyIdentifier = _configuration[Constants.KeyIdentifier];
//create azurekeyvault client
var client = GetAzureKeyVaultClient();
var certificateBundle = await client.GetSecretAsync(KeyIdentifier);
//insert missing newlines that cause a problem on reading the certificate
var sections = certificateBundle.Value.Split("-----BEGIN RSA PRIVATE KEY-----", StringSplitOptions.RemoveEmptyEntries);
sections = sections[0].Split("-----END RSA PRIVATE KEY-----", StringSplitOptions.RemoveEmptyEntries);
//insert missing newlines that cause a problem on reading the certificate
string key = "-----BEGIN RSA PRIVATE KEY-----\r\n" + sections[0] + "\r\n-----END RSA PRIVATE KEY-----";
var utcNow = DateTime.UtcNow;
var payload = new Dictionary <string, object>
{
{ "iat", ToUtcSeconds(utcNow) },
{ "exp", ToUtcSeconds(utcNow.AddSeconds(600)) },
{ "iss", 62050 }
};
var jwtToken = JWTHelper.CreateEncodedJwtToken(key, payload);
// Pass the JWT as a Bearer token to Octokit.net
var appClient = new GitHubClient(new ProductHeaderValue(_configuration.GetValue <string>("product")))
{
Credentials = new Credentials(jwtToken, AuthenticationType.Bearer)
};
// Get a list of installations for the authenticated GitHubApp and installationID for microsoftgraph
var installations = await appClient.GitHubApps.GetAllInstallationsForCurrent();
var id = installations.Where(installation => installation.Account.Login == "microsoftgraph").FirstOrDefault().Id;
// Create an Installation token for the microsoftgraph installation instance
var response = await appClient.GitHubApps.CreateInstallationToken(id);
token = response.Token;
//set cache to expire at the same time as the token
var cacheEntryOptions = new MemoryCacheEntryOptions().SetAbsoluteExpiration(response.ExpiresAt);
_cache.Set(Constants.GitHubToken, token, cacheEntryOptions);
return(token);
}