/// <summary>
/// Provisions a certificate in the central store
/// </summary>
/// <param name="hostName">Domain to register</param>
/// <param name="email">Registration e-mail</param>
/// <param name="bindingInfo">IIS binding info</param>
/// <param name="ownerSiteName">The site that owns the binding, used to assign identity and application pool permissions.</param>
/// <param name="forceSelfSigned">Force a self-signed certificate</param>
/// <param name="forceRenewal">Force renewal, even if renewal conditions are not met</param>
/// <returns>The certificate's friendly name, ready to be bound in IIS</returns>
public void ProvisionCertificateInIis(
string hostName,
string email,
string bindingInfo,
string ownerSiteName,
bool forceSelfSigned = false,
bool forceRenewal = false)
{
if (hostName.Contains("*"))
{
throw new Exception($"Provisioning certificates for wildcard host name '{hostName}' is not supported.");
}
var currentCertificate = UtilsIis.FindCertificateInCentralCertificateStore(hostName, this.Logger, out _);
double remainingCertificateDays = (currentCertificate?.NotAfter - DateTime.Now)?.TotalDays ?? 0;
this.Logger.LogInfo(true, "Total days remaining for certificate expiration: '{0}'", (int)Math.Floor(remainingCertificateDays));
// Trigger renovation. Do this differently on mock/prod environment.
// Next renewal attempt is calculated based on previous renewal attempt
var renewalState = this.GetCertificateRenewalState(hostName);
// Legacy apps don't have this set, or when a certificate has been manually placed
if (renewalState.NextRenewal == null && remainingCertificateDays > 1)
{
renewalState.NextRenewal = this.CalculateNextRenewalAttempt(hostName, (int)remainingCertificateDays);
this.StoreCertificateRenewalState(renewalState);
}
int remainingDaysForNextRenewal = renewalState.NextRenewal == null ? 0 : (int)(renewalState.NextRenewal - DateTime.UtcNow).Value.TotalDays;
int certificateTotalDuration = currentCertificate == null ? 0 : (int)(currentCertificate.NotAfter - currentCertificate.NotBefore).TotalDays;
this.Logger.LogInfo(true, "Next renewal attempt for this site SSL targeted in '{0}' days.", remainingDaysForNextRenewal);
// Check that the validationfailed request rate is not exceeded for this domain
if (!forceRenewal && renewalState.FailedValidations.AsIterable().Count(i => (DateTime.UtcNow - i).TotalHours < 48) >= 2)
{
// Make this message verbos so that it will not flood the logs, the failed validation message will get logged
// anyways and is sufficient.
this.Logger.LogWarning(true, "The hostname '{0}' has reached the limit of two failed validations in the last 48 hours.", hostName);
return;
}
if (!forceRenewal && !forceSelfSigned && remainingDaysForNextRenewal > 0 && remainingCertificateDays > 0)
{
this.Logger.LogWarning(true, "Next renewal attempt date not reached, skipping SSL provisioning.");
return;
}
if (!forceRenewal && remainingDaysForNextRenewal > 0 && (remainingDaysForNextRenewal > certificateTotalDuration * 0.5) && certificateTotalDuration > 0)
{
this.Logger.LogWarning(false, "Certificate has not yet been through at least 50% of it's lifetime so it will not be renewed.'");
renewalState.NextRenewal = this.CalculateNextRenewalAttempt(hostName, (int)remainingCertificateDays);
this.StoreCertificateRenewalState(renewalState);
return;
}
// Check the general too many requests rate exceeded
if (!forceRenewal && this.SimpleStoreRenewalStatus.Get <bool>("ssl-certificate-provider-too-many-requests", out var tooManyRequests))
{
this.Logger.LogWarning(false, "Certificate provisioning temporarily disabled due to a Too Many Requests ACME error. Flag stored in {0}", tooManyRequests.StorePath);
return;
}
this.Logger.LogInfo(false, "Attempting SSL certificate renewal for site '{0}' and host '{1}'", ownerSiteName, hostName);
// Clear old validation failed requests
if (renewalState.FailedValidations?.Any() == true)
{
// Only keep failed validations that happen in the last 5 days
renewalState.FailedValidations = renewalState.FailedValidations
.Where((i) => (DateTime.UtcNow - i).TotalDays < 5).ToList();
}
// This is a little bit inconvenient but... the most reliable and compatible
// way to do this is to setup a custom IIS website that uses the binding during
// provisioning.
long tempSiteId;
List <Site> haltedSites = new List <Site>();
var tempSiteName = "cert-" + this.AppId;
var tempSiteAppId = "cert-" + this.AppId;
string tempHostName = "localcert-" + hostName;
this.Logger.LogInfo(true, "Preparing temp site: " + tempSiteName);
List <Site> conflictingSites;
// Prepare the site
using (ServerManager sm = new ServerManager())
{
// Query the sites in a resilient way...
conflictingSites = UtilsSystem.QueryEnumerable(
sm.Sites,
(s) => s.State == ObjectState.Started && s.Bindings.Any((i) => i.Host.Equals(hostName)),
(s) => s,
(s) => s.Name,
this.Logger);
}
// Stop the sites that might prevent this one from starting
foreach (var s in conflictingSites)
{
this.Logger.LogInfo(true, "Stopping site {0} to avoid binding collision.", s.Name);
this.AppPoolUtils.WebsiteAction(s.Name, AppPoolActionType.Stop, skipApplicationPools: true);
haltedSites.Add(s);
}
using (ServerManager sm = new ServerManager())
{
// Make sure there is no other site (might be stuck?)
var existingSite = (from p in sm.Sites
where p.Name == tempSiteName
select p).FirstOrDefault();
var tempSite = existingSite ?? sm.Sites.Add(tempSiteName, this.GetAcmeTemporarySiteRootForApplication(), 80);
// Propagate application pool usage so that permissions are properly handled.
var ownerSite = sm.Sites.First((i) => i.Name == ownerSiteName);
tempSite.Applications.First().ApplicationPoolName = ownerSite.Applications.First().ApplicationPoolName;
// Delete all bindings
tempSite.Bindings.Clear();
tempSite.Bindings.Add(bindingInfo, "http");
tempSite.Bindings.Add($"{UtilsIis.LOCALHOST_ADDRESS}:80:" + tempHostName, "http");
tempSiteId = tempSite.Id;
this.UtilsHosts.AddHostsMapping(UtilsIis.LOCALHOST_ADDRESS, tempHostName, tempSiteAppId);
// Prepare the website contents
var sourceDir = UtilsSystem.FindResourcePhysicalPath(typeof(IISDeployer), ".well-known");
UtilsSystem.CopyFilesRecursively(new DirectoryInfo(sourceDir), new DirectoryInfo(this.GetWellKnownSharedPathForApplication()), true);
UtilsIis.CommitChanges(sm);
}
UtilsIis.WaitForSiteToBeAvailable(tempSiteName, this.Logger);
UtilsIis.ConfigureAnonymousAuthForIisApplication(tempSiteName, this.Deployment.WindowsUsernameFqdn(), this.Deployment.GetWindowsPassword());
IAcmeSharpProvider provider = null;
try
{
this.AppPoolUtils.WebsiteAction(tempSiteName, AppPoolActionType.Start);
// Check that the site does work using the local binding
var testDataUrl = $"http://{tempHostName}/.well-known/acme-challenge/test.html";
this.Logger.LogInfo(true, "Validating local challenge setup at: {0}", testDataUrl);
if (!string.Equals(UtilsSystem.DownloadUriAsText(testDataUrl), "test data"))
{
throw new Exception($"Could not locally validate acme challenge site setup at {testDataUrl}");
}
// Ssl registration configuration only depends on the e-mail and is signed as such
string sslSignerAndRegistrationStoragePath = UtilsSystem.EnsureDirectoryExists(
UtilsSystem.CombinePaths(this.StoragePath, "_ssl_config", StringFormating.Instance.ExtremeClean(email)), true);
// Initialize the provider
bool useMockProvider = this.MockEnvironment || forceSelfSigned;
provider = useMockProvider
? (IAcmeSharpProvider) new AcmeSharpProviderMock(this.Logger, tempHostName)
: this.GetAcmeProvider(this.Logger, hostName);
var signerPath = Path.Combine(this.StoragePath, "_signer.xml");
var registrationPath = Path.Combine(sslSignerAndRegistrationStoragePath, "registration.json");
provider.InitRegistration(signerPath, registrationPath, email);
string challengeUrl;
string challengeContent;
string challengeFilePath;
try
{
provider.GenerateHttpChallenge(
out challengeUrl,
out challengeContent,
out challengeFilePath);
}
catch (AcmeClient.AcmeWebException acmeException)
{
if (acmeException.Message.Contains("429"))
{
int waitHours = 1;
this.SimpleStoreRenewalStatus.Set("ssl-certificate-provider-too-many-requests", true, 60 * waitHours);
this.Logger.LogError("Let's encrypt too many requests issue. Certificate provisioning disabled for the next {0} hours.", waitHours);
this.Logger.LogException(acmeException, EventLogEntryType.Warning);
return;
}
throw;
}
// Write the challanege contents
string challengeFullPath =
Path.Combine(this.GetAcmeTemporarySiteRootForApplication(), challengeFilePath);
File.WriteAllText(
challengeFullPath,
challengeContent);
this.Logger.LogInfo(false, $"Veryfing challenge at '{challengeUrl}'");
try
{
// Validate that we can actually access the challenge ourselves!
string contents = UtilsSystem.DownloadUriAsText(challengeUrl, false);
if (!string.Equals(contents, challengeContent))
{
throw new Exception(
$"Could not validate ACME challenge, retrieved challenge '{contents}' does not match '{challengeContent}'");
}
}
catch (Exception e)
{
this.Logger.LogWarning(true, "Cannot self-verify auth challenge, this can sometimes happeen under some DNS setups. {0}", e.Message + Environment.NewLine + e.InnerException?.Message);
}
var challengeValidated = false;
try
{
challengeValidated = provider.ValidateChallenge();
}
catch (Exception e)
{
this.Logger.LogException(e, EventLogEntryType.Warning);
}
this.Logger.LogWarning(true, "Remote challenge validation success: " + (challengeValidated ? "Yes" : "No"));
// Download the certificates to this temp location
string temporaryCertificatePath = UtilsSystem.EnsureDirectoryExists(UtilsSystem.CombinePaths(this.StoragePath, this.AppId, "ssl_certificates", hostName), true);
CertificatePaths certificatepaths = null;
// This is here for testing purposes
if (Environment.GetEnvironmentVariable("TEST_FAIL_CHALLENGE_VALIDATION") == true.ToString())
{
challengeValidated = false;
}
if (!challengeValidated)
{
// There is a Failed Validation limit of 5 failures per account, per hostname, per hour.
renewalState.FailedValidations = renewalState.FailedValidations ?? new List <DateTime>();
renewalState.FailedValidations.Add(DateTime.UtcNow);
this.Logger.LogError(
"Challenge could not be validated at '{0}'. If behind a load balancer, make sure that the site is deployed in ALL nodes, remove the self-signed certificate from the store and redeploy the application.",
challengeUrl);
this.StoreCertificateRenewalState(renewalState);
}
else
{
try
{
certificatepaths = provider.DownloadCertificate(
UtilsEncryption.GetMD5(hostName),
hostName,
temporaryCertificatePath);
}
catch (AcmeClient.AcmeWebException acmeException)
{
this.Logger.LogException(acmeException, EventLogEntryType.Warning);
}
catch (WebException webException)
{
this.Logger.LogException(webException, EventLogEntryType.Warning);
}
catch (Exception e)
{
this.Logger.LogException(e, EventLogEntryType.Warning);
}
}
if (certificatepaths == null && currentCertificate == null)
{
this.Logger.LogWarning(false, "Unable to acquire certificate and site does not have a valid existing one, using self-signed fallback.");
provider = new AcmeSharpProviderMock(this.Logger, hostName);
certificatepaths = provider.DownloadCertificate(
UtilsEncryption.GetMD5(hostName),
hostName,
temporaryCertificatePath);
}
// Save this, use a fixed name certificate file
if (certificatepaths != null)
{
string certificateFilePath = Path.Combine(UtilsIis.CentralStorePath(this.Logger), hostName + ".pfx");
UtilsSystem.RetryWhile(
() => { File.Copy(certificatepaths.pfxPemFile, certificateFilePath, true); },
(e) => true,
2500,
this.Logger);
this.Logger.LogInfo(false, "Certificate file writen to '{0}'", certificateFilePath);
// TODO: Activate this refreshing when it's prooved to work
// UtilsIis.EnsureCertificateInCentralCertificateStoreIsRebound(hostName, this.Logger);
}
// Remove temporary certificates
UtilsSystem.DeleteDirectory(temporaryCertificatePath, this.Logger);
// Remove the already used challenge if it was validated. Otherwise keep it
// for debugging purposes.
if (challengeValidated && File.Exists(challengeFullPath))
{
File.Delete(challengeFullPath);
}
// In the end, we always have a certificate. Program a renewal date according to the remaining expiration.
currentCertificate = UtilsIis.FindCertificateInCentralCertificateStore(hostName, this.Logger, out _);
remainingCertificateDays = (currentCertificate?.NotAfter - DateTime.Now)?.TotalDays ?? 0;
// Add some randomness in renewal dates to avoid all certificates being renewed at once and reaching api limits
renewalState.LastRenewal = DateTime.UtcNow;
renewalState.NextRenewal = this.CalculateNextRenewalAttempt(hostName, (int)remainingCertificateDays);
this.StoreCertificateRenewalState(renewalState);
}
finally
{
this.Logger.LogInfo(true, "Disposing temporary verification setup");
provider?.Dispose();
this.UtilsHosts.RemoveHostsMapping(tempSiteAppId);
// Restore the original state of IIS!!!
using (ServerManager sm = new ServerManager())
{
var site = sm.Sites.Single(i => i.Id == tempSiteId);
UtilsIis.RemoveSite(site, sm, this.Logger);
UtilsIis.CommitChanges(sm);
}
// Give IIS some time to reconfigure itself and free resources.
Thread.Sleep(1000);
// Start the sites
foreach (var site in haltedSites)
{
// Add some retry logic here because bringing the original sites online is critical
UtilsSystem.RetryWhile(() => { this.AppPoolUtils.WebsiteAction(site.Name, AppPoolActionType.Start); }, (e) => true, 5000, this.Logger);
}
}
}