adding two more examples for preservation

cmd/match-path/main.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	policy := "/osb/v2/service_instances/{instance_id}/service_bindings/{binding_id}/last_operation"
+	pathGood := "/osb/v2/service_instances/foo/service_bindings/bar/last_operation"
+	pathBad := "/osb/v2/service_instances/foo/evil_path/service_bindings/bar/last_operation"
+	pathShort := "/osb/v2/service_instances/foo_bar/"
+
+	fmt.Printf("Valid Path: %s\n", strconv.FormatBool(checkPolicyMatch(policy, pathGood)))
+	fmt.Printf("Valid Path: %s\n", strconv.FormatBool(checkPolicyMatch(policy, pathBad)))
+	fmt.Printf("Valid Path: %s\n", strconv.FormatBool(checkPolicyMatch(policy, pathShort)))
+}
+
+func checkPolicyMatch(policy, path string) bool {
+	// split the path elements by "/"
+	policyElements := strings.Split(policy, "/")
+	pathElements := strings.Split(path, "/")
+
+	// check to see if the number of elements are present in the path to prevent index out of range error
+	if len(policyElements) > len(pathElements) {
+		return false
+	}
+
+	// check each path element
+	for i := 0; i < len(policyElements); i++ {
+		switch {
+		// policy matching wildcard **
+		case regexp.MustCompile(`^\*\*$`).MatchString(policyElements[i]):
+			continue
+		// policy matching wildcard {foo}
+		case regexp.MustCompile(`^\{.+\}$`).MatchString(policyElements[i]):
+			continue
+		// path matches exactly, should we ignore case with EqualFold()
+		case policyElements[i] == pathElements[i]:
+			continue
+		// default deny
+		default:
+			return false
+		}
+	}
+
+	return true
+}