/// <summary>
/// Asks the user whether they trust a given key for a specific domain. May automatically accept based on policy.
/// </summary>
/// <param name="uri">The URI the signed file originally came from.</param>
/// <param name="fingerprint">The fingerprint of the key to trust.</param>
/// <param name="domain">The domain to trust the key for.</param>
/// <returns><c>true</c> if the user decided to trust the key, <c>false</c> if they decided not to trust the key.</returns>
/// <exception cref="OperationCanceledException">The user canceled the task.</exception>
private bool AskKeyApproval(FeedUri uri, string fingerprint, Domain domain)
{
(bool goodVote, string?keyInformation) = GetKeyInformation(fingerprint);
// Automatically trust key for _new_ feeds if voted good by key server
if (_config.AutoApproveKeys && goodVote && !_feedCache.Contains(uri))
{
Log.Info("Auto-approving key for " + uri.ToStringRfc());
return(true);
}
// Otherwise ask user
return(_handler.Ask(
string.Format(Resources.AskKeyTrust, uri.ToStringRfc(), fingerprint, keyInformation ?? Resources.NoKeyInfoServerData, domain),
defaultAnswer: false, alternateMessage: Resources.UntrustedKeys));
}
//--------------------//
#region Get feed
/// <inheritdoc/>
public Feed GetFeed(FeedUri feedUri)
{
#region Sanity checks
if (feedUri == null)
{
throw new ArgumentNullException("feedUri");
}
#endregion
if (feedUri.IsFile)
{
return(LoadLocal(feedUri));
}
else
{
try
{
if (Refresh)
{
Download(feedUri);
}
else if (!_feedCache.Contains(feedUri))
{
// Do not download in offline mode
if (_config.NetworkUse == NetworkLevel.Offline)
{
throw new IOException(string.Format(Resources.FeedNotCachedOffline, feedUri));
}
// Try to download missing feed
Download(feedUri);
}
return(LoadCached(feedUri));
}
#region Error handling
catch (KeyNotFoundException ex)
{
// Wrap exception since only certain exception types are allowed
throw new IOException(ex.Message, ex);
}
#endregion
}
}
/// <summary>
/// Returns a specific <see cref="Feed"/>. Automatically handles downloading and caching. Updates the <see cref="Stale"/> indicator.
/// </summary>
/// <param name="feedUri">The canonical ID used to identify the feed.</param>
/// <returns>The parsed <see cref="Feed"/> object.</returns>
/// <remarks><see cref="Feed"/>s are always served from the <see cref="IFeedCache"/> if possible, unless <see cref="Refresh"/> is set to <c>true</c>.</remarks>
/// <exception cref="OperationCanceledException">The user canceled the task.</exception>
/// <exception cref="WebException">A problem occured while fetching the feed file.</exception>
/// <exception cref="IOException">A problem occured while reading the feed file.</exception>
/// <exception cref="UnauthorizedAccessException">Access to the cache is not permitted.</exception>
/// <exception cref="SignatureException">The signature data of a remote feed file could not be verified.</exception>
/// <exception cref="InvalidDataException"><see cref="Feed.Uri"/> is missing or does not match <paramref name="feedUri"/>.</exception>
private Feed GetFeed([NotNull] FeedUri feedUri)
{
if (feedUri.IsFromDistribution)
{
throw new ArgumentException($"{feedUri.ToStringRfc()} is a virtual feed URI and therefore cannot be downloaded.");
}
if (feedUri.IsFile)
{
return(XmlStorage.LoadXml <Feed>(feedUri.LocalPath));
}
else
{
try
{
if (Refresh)
{
Download(feedUri);
}
else if (!_feedCache.Contains(feedUri))
{
// Do not download in offline mode
if (_config.NetworkUse == NetworkLevel.Offline)
{
throw new IOException(string.Format(Resources.FeedNotCachedOffline, feedUri));
}
// Try to download missing feed
Download(feedUri);
}
return(LoadCached(feedUri));
}
#region Error handling
catch (KeyNotFoundException ex)
{
// Wrap exception since only certain exception types are allowed
throw new IOException(ex.Message, ex);
}
#endregion
}
}
//--------------------//
#region Contains
/// <inheritdoc/>
public bool Contains(FeedUri feedUri)
{
return(_backingCache.Contains(feedUri));
}