private static void DownloadAndAddCrl(
string url,
string crlFileName,
SafeX509StoreHandle store,
TimeSpan downloadTimeout)
{
// X509_STORE_add_crl will increase the refcount on the CRL object, so we should still
// dispose our copy.
using (SafeX509CrlHandle? crl = OpenSslCertificateAssetDownloader.DownloadCrl(url, downloadTimeout))
{
// null is a valid return (e.g. no remainingDownloadTime)
if (crl != null && !crl.IsInvalid)
{
if (!Interop.Crypto.X509StoreAddCrl(store, crl))
{
// Ignore error "cert already in store", throw on anything else. In any case the error queue will be cleared.
if (X509_R_CERT_ALREADY_IN_HASH_TABLE == Interop.Crypto.ErrPeekLastError())
{
Interop.Crypto.ErrClearError();
}
else
{
throw Interop.Crypto.CreateOpenSslCryptographicException();
}
}
// Saving the CRL to the disk is just a performance optimization for later requests to not
// need to use the network again, so failure to save shouldn't throw an exception or mark
// the chain as invalid.
try
{
string crlFile = GetCachedCrlPath(crlFileName, mkDir: true);
using (SafeBioHandle bio = Interop.Crypto.BioNewFile(crlFile, "wb"))
{
if (bio.IsInvalid || Interop.Crypto.PemWriteBioX509Crl(bio, crl) == 0)
{
// No bio, or write failed
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlCacheWriteFailed(crlFile);
}
Interop.Crypto.ErrClearError();
}
}
}
catch (UnauthorizedAccessException) { }
catch (IOException) { }
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlCacheWriteSucceeded();
}
}
}
}
public static AndroidKeyStore OpenDefault(OpenFlags openFlags)
{
SafeX509StoreHandle store = Interop.AndroidCrypto.X509StoreOpenDefault();
if (store.IsInvalid)
{
store.Dispose();
throw new CryptographicException();
}
return(new AndroidKeyStore(store, openFlags));
}
public static void AddCrlForCertificate(
SafeX509Handle cert,
SafeX509StoreHandle store,
X509RevocationMode revocationMode,
DateTime verificationTime,
TimeSpan downloadTimeout)
{
// In Offline mode, accept any cached CRL we have.
// "CRL is Expired" is a better match for Offline than "Could not find CRL"
if (revocationMode != X509RevocationMode.Online)
{
verificationTime = DateTime.MinValue;
}
string?url = GetCdpUrl(cert);
if (url == null)
{
return;
}
string crlFileName = GetCrlFileName(cert, url);
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlIdentifiersDetermined(cert, url, crlFileName);
}
if (AddCachedCrl(crlFileName, store, verificationTime))
{
return;
}
// Don't do any work if we're prohibited from fetching new CRLs
if (revocationMode != X509RevocationMode.Online)
{
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlCheckOffline();
}
return;
}
DownloadAndAddCrl(url, crlFileName, store, downloadTimeout);
}
private static bool AddCachedCrl(string crlFileName, SafeX509StoreHandle store, DateTime verificationTime)
{
string crlFile = GetCachedCrlPath(crlFileName);
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlCacheCheckStart();
}
try
{
return(AddCachedCrlCore(crlFile, store, verificationTime));
}
finally
{
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlCacheCheckStop();
}
}
}
private AndroidKeyStore(SafeX509StoreHandle keyStoreHandle, OpenFlags openFlags)
{
_keyStoreHandle = keyStoreHandle;
_readOnly = (openFlags & (OpenFlags.ReadWrite | OpenFlags.MaxAllowed)) == 0;
}
private static bool AddCachedCrlCore(string crlFile, SafeX509StoreHandle store, DateTime verificationTime)
{
using (SafeBioHandle bio = Interop.Crypto.BioNewFile(crlFile, "rb"))
{
if (bio.IsInvalid)
{
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlCacheOpenError();
}
Interop.Crypto.ErrClearError();
return(false);
}
// X509_STORE_add_crl will increase the refcount on the CRL object, so we should still
// dispose our copy.
using (SafeX509CrlHandle crl = Interop.Crypto.PemReadBioX509Crl(bio))
{
if (crl.IsInvalid)
{
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlCacheDecodeError();
}
Interop.Crypto.ErrClearError();
return(false);
}
// If crl.LastUpdate is in the past, downloading a new version isn't really going
// to help, since we can't rewind the Internet. So this is just going to fail, but
// at least it can fail without using the network.
//
// If crl.NextUpdate is in the past, try downloading a newer version.
IntPtr nextUpdatePtr = Interop.Crypto.GetX509CrlNextUpdate(crl);
DateTime nextUpdate;
// If there is no crl.NextUpdate, this indicates that the CA is not providing
// any more updates to the CRL, or they made a mistake not providing a NextUpdate.
// We'll cache it for a few days to cover the case it was a mistake.
if (nextUpdatePtr == IntPtr.Zero)
{
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlCacheFileBasedExpiry();
}
try
{
nextUpdate = File.GetLastWriteTime(crlFile).AddDays(3);
}
catch
{
// We couldn't determine when the CRL was last written to,
// so consider it expired.
Debug.Fail("Failed to get the last write time of the CRL file");
return(false);
}
}
else
{
nextUpdate = OpenSslX509CertificateReader.ExtractValidityDateTime(nextUpdatePtr);
}
// OpenSSL is going to convert our input time to universal, so we should be in Local or
// Unspecified (local-assumed).
Debug.Assert(
verificationTime.Kind != DateTimeKind.Utc,
"UTC verificationTime should have been normalized to Local");
// In the event that we're to-the-second accurate on the match, OpenSSL will consider this
// to be already expired.
if (nextUpdate <= verificationTime)
{
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlCacheExpired(nextUpdate, verificationTime);
}
return(false);
}
if (!Interop.Crypto.X509StoreAddCrl(store, crl))
{
// Ignore error "cert already in store", throw on anything else. In any case the error queue will be cleared.
if (X509_R_CERT_ALREADY_IN_HASH_TABLE == Interop.Crypto.ErrPeekLastError())
{
Interop.Crypto.ErrClearError();
}
else
{
throw Interop.Crypto.CreateOpenSslCryptographicException();
}
}
if (OpenSslX509ChainEventSource.Log.IsEnabled())
{
OpenSslX509ChainEventSource.Log.CrlCacheAcceptedFile(nextUpdate);
}
return(true);
}
}
}
