public override void Analyze(AnalyzeContext context)
{
if (context.FileContents == null)
{
context.FileContents = _fileSystem.FileReadAllText(context.TargetUri.LocalPath);
}
string filePath = context.TargetUri.GetFilePath();
foreach (MatchExpression matchExpression in _matchExpressions)
{
if (!string.IsNullOrEmpty(matchExpression.FileNameAllowRegex))
{
if (!_engine.IsMatch(filePath,
matchExpression.FileNameAllowRegex,
RegexDefaults.DefaultOptionsCaseInsensitive))
{
continue;
}
}
if (!string.IsNullOrEmpty(matchExpression.FileNameDenyRegex))
{
if (_engine.IsMatch(filePath,
matchExpression.FileNameDenyRegex,
RegexDefaults.DefaultOptionsCaseInsensitive))
{
continue;
}
}
if (matchExpression.MatchLengthToDecode > 0)
{
decimal unencodedLength = matchExpression.MatchLengthToDecode;
// Every 3 bytes of a base64-encoded string produces 4 bytes of data.
int unpaddedLength = (int)Math.Ceiling(decimal.Divide(unencodedLength * 8M, 6M));
int paddedLength = 4 * (int)Math.Ceiling(decimal.Divide(unencodedLength, 3M));
// Create proper regex for base64-encoded string which includes padding characters.
string base64DecodingRegexText =
string.Format(Base64DecodingFormatString, "{" + unpaddedLength + "}") +
new string('=', paddedLength - unpaddedLength);
foreach (FlexMatch flexMatch in _engine.Matches(context.FileContents, base64DecodingRegexText))
{
// This will run the match expression against the decoded content.
RunMatchExpression(
binary64DecodedMatch: flexMatch,
context,
matchExpression);
}
}
// This runs the match expression against the entire, unencoded file.
RunMatchExpression(
binary64DecodedMatch: null,
context,
matchExpression);
}
}
public static IEnumerable <string> Matches(this IRegex c, string parent)
{
return(c.Matches(parent, 1, RegexOptions.None));
}