Method matchPatternWithEscapeSequence

modules/caddyhttp/matchers.go:545–649

(escapedPath, matchPath string)

}

func (MatchPath) matchPatternWithEscapeSequence(escapedPath, matchPath string) bool {
	escapedPath = strings.ToLower(escapedPath)
	// We would just compare the pattern against r.URL.Path,
	// but the pattern contains %, indicating that we should
	// compare at least some part of the path in raw/escaped
	// space, not normalized space; so we build the string we
	// will compare against by adding the normalized parts
	// of the path, then switching to the escaped parts where
	// the pattern hints to us wherever % is present.
	var sb strings.Builder

	// iterate the pattern and escaped path in lock-step;
	// increment iPattern every time we consume a char from the pattern,
	// increment iPath every time we consume a char from the path;
	// iPattern and iPath are our cursors/iterator positions for each string
	var iPattern, iPath int
	for {
		if iPattern >= len(matchPath) || iPath >= len(escapedPath) {
			break
		}
		// get the next character from the request path

		pathCh := string(escapedPath[iPath])
		var escapedPathCh string

		// normalize (decode) escape sequences
		if pathCh == "%" && len(escapedPath) >= iPath+3 {
			// hold onto this in case we find out the intent is to match in escaped space here;
			// we lowercase it even though technically the spec says: "For consistency, URI
			// producers and normalizers should use uppercase hexadecimal digits for all percent-
			// encodings" (RFC 3986 section 2.1) - we lowercased the matcher pattern earlier in
			// provisioning so we do the same here to gain case-insensitivity in equivalence;
			// besides, this string is never shown visibly
			escapedPathCh = strings.ToLower(escapedPath[iPath : iPath+3])

			var err error
			pathCh, err = url.PathUnescape(escapedPathCh)
			if err != nil {
				// should be impossible unless EscapedPath() is giving us an invalid sequence!
				return false
			}
			iPath += 2 // escape sequence is 2 bytes longer than normal char
		}

		// now get the next character from the pattern

		normalize := true
		switch matchPath[iPattern] {
		case '%':
			// escape sequence

			// if not a wildcard ("%*"), compare literally; consume next two bytes of pattern
			if len(matchPath) >= iPattern+3 && matchPath[iPattern+1] != '*' {
				sb.WriteString(escapedPathCh)
				iPath++
				iPattern += 2
				break
			}