/// <summary>
/// Validates a URL against this trust root.
/// </summary>
/// <param name="url">The URL to check.</param>
/// <returns>Whether the given URL is within this trust root.</returns>
internal bool Contains(Uri url)
{
if (url.Scheme != Scheme)
{
return(false);
}
if (url.Port != Port)
{
return(false);
}
if (!DomainWildcard)
{
if (url.Host != Host)
{
return(false);
}
}
else
{
Debug.Assert(!string.IsNullOrEmpty(Host), "The host part of the Regex should evaluate to at least one char for successful parsed trust roots.");
string[] host_parts = Host.Split('.');
string[] url_parts = url.Host.Split('.');
// If the domain containing the wildcard has more parts than the URL to match against,
// it naturally can't be valid.
// Unless *.example.com actually matches example.com too.
if (host_parts.Length > url_parts.Length)
{
return(false);
}
// Compare last part first and move forward.
// Maybe could be done by using EndsWith, but piecewies helps ensure that
// *.my.com doesn't match ohmeohmy.com but can still match my.com.
for (int i = 0; i < host_parts.Length; i++)
{
string hostPart = host_parts[host_parts.Length - 1 - i];
string urlPart = url_parts[url_parts.Length - 1 - i];
if (!string.Equals(hostPart, urlPart, StringComparison.OrdinalIgnoreCase))
{
return(false);
}
}
}
// If path matches or is specified to root ...
// (deliberately case sensitive to protect security on case sensitive systems)
if (PathAndQuery.Equals(url.PathAndQuery, StringComparison.Ordinal) ||
PathAndQuery.Equals("/", StringComparison.Ordinal))
{
return(true);
}
// If trust root has a longer path, the return URL must be invalid.
if (PathAndQuery.Length > url.PathAndQuery.Length)
{
return(false);
}
// The following code assures that http://example.com/directory isn't below http://example.com/dir,
// but makes sure http://example.com/dir/ectory is below http://example.com/dir
int path_len = PathAndQuery.Length;
string url_prefix = url.PathAndQuery.Substring(0, path_len);
if (PathAndQuery != url_prefix)
{
return(false);
}
// If trust root includes a query string ...
if (PathAndQuery.Contains("?"))
{
// ... make sure return URL begins with a new argument
return(url.PathAndQuery[path_len] == '&');
}
// Or make sure a query string is introduced or a path below trust root
return(PathAndQuery.EndsWith("/", StringComparison.Ordinal) ||
url.PathAndQuery[path_len] == '?' ||
url.PathAndQuery[path_len] == '/');
}
