initial commit [ci skip]

internal/match/match.go

@@ -0,0 +1,51 @@
+// Copyright 2019 Drone.IO Inc. All rights reserved.
+// Use of this source code is governed by the Polyform License
+// that can be found in the LICENSE file.
+
+package match
+
+import (
+	"path/filepath"
+
+	"github.com/drone/drone-go/drone"
+)
+
+// NOTE most runners do not require match capabilities. This is
+// provided as a defense in depth mechanism given the sensitive
+// nature of this runner executing code directly on the host.
+// The matching function is a last line of defence to prevent
+// unauthorized code from running on the host machine.
+
+// Func returns a new match function that returns true if the
+// repository and build do not match the allowd repository names
+// and build events.
+func Func(repos, events []string, trusted bool) func(*drone.Repo, *drone.Build) bool {
+	return func(repo *drone.Repo, build *drone.Build) bool {
+		// if trusted mode is enabled, only match repositories
+		// that are trusted.
+		if trusted && repo.Trusted == false {
+			return false
+		}
+		if match(repo.Slug, repos) == false {
+			return false
+		}
+		if match(build.Event, events) == false {
+			return false
+		}
+		return true
+	}
+}
+
+func match(s string, patterns []string) bool {
+	// if no matching patterns are defined the string
+	// is always considered a match.
+	if len(patterns) == 0 {
+		return true
+	}
+	for _, pattern := range patterns {
+		if match, _ := filepath.Match(pattern, s); match {
+			return true
+		}
+	}
+	return false
+}