processing_handler.go -> handlers/processing

handlers/processing/path.go

@@ -0,0 +1,56 @@
+package processing
+
+import (
+	"fmt"
+	"net/http"
+	"regexp"
+	"strings"
+
+	"github.com/imgproxy/imgproxy/v3/ierrors"
+)
+
+// fixPathRe is used in path re-denormalization
+var fixPathRe = regexp.MustCompile(`/plain/(\S+)\:/([^/])`)
+
+// splitPathSignature splits signature and path components from the request URI
+func splitPathSignature(r *http.Request, config *Config) (string, string, error) {
+	uri := r.RequestURI
+
+	// cut query params
+	uri, _, _ = strings.Cut(uri, "?")
+
+	// cut path prefix
+	if len(config.PathPrefix) > 0 {
+		uri = strings.TrimPrefix(uri, config.PathPrefix)
+	}
+
+	// cut leading slash
+	uri = strings.TrimPrefix(uri, "/")
+
+	signature, path, _ := strings.Cut(uri, "/")
+	if len(signature) == 0 || len(path) == 0 {
+		return "", "", ierrors.Wrap(
+			newInvalidURLErrorf(http.StatusNotFound, "Invalid path: %s", path), 0,
+			ierrors.WithCategory(categoryPathParsing),
+		)
+	}
+
+	// restore broken slashes in the path
+	path = redenormalizePath(path)
+
+	return path, signature, nil
+}
+
+// redenormalizePath undoes path normalization done by some browsers and revers proxies
+func redenormalizePath(path string) string {
+	for _, match := range fixPathRe.FindAllStringSubmatch(path, -1) {
+		repl := fmt.Sprintf("/plain/%s://", match[1])
+		if match[1] == "local" {
+			repl += "/"
+		}
+		repl += match[2]
+		path = strings.Replace(path, match[0], repl, 1)
+	}
+
+	return path
+}