Add HTTP authentication for mailhog/MailHog#40

server.go

@@ -1,20 +1,102 @@
 package http
 
 import (
+	"bytes"
+	"io"
+	"io/ioutil"
 	"net/http"
+	"os"
+	"strings"
 
 	"github.com/gorilla/pat"
 	"github.com/ian-kent/go-log/log"
+	"golang.org/x/crypto/bcrypt"
 )
 
+// Authorised should be given a function to enable HTTP Basic Authentication
+var Authorised func(string, string) bool
+var users map[string]string
+
+// AuthFile sets Authorised to a function which validates against file
+func AuthFile(file string) {
+	users = make(map[string]string)
+
+	b, err := ioutil.ReadFile(file)
+	if err != nil {
+		log.Fatalf("[HTTP] Error reading auth-file: %s", err)
+		// FIXME - go-log
+		os.Exit(1)
+	}
+
+	buf := bytes.NewBuffer(b)
+
+	for {
+		l, err := buf.ReadString('\n')
+		l = strings.TrimSpace(l)
+		if len(l) > 0 {
+			p := strings.SplitN(l, ":", 2)
+			if len(p) < 2 {
+				log.Fatalf("[HTTP] Error reading auth-file, invalid line: %s", l)
+				// FIXME - go-log
+				os.Exit(1)
+			}
+			users[p[0]] = p[1]
+		}
+		switch {
+		case err == io.EOF:
+			break
+		case err != nil:
+			log.Fatalf("[HTTP] Error reading auth-file: %s", err)
+			// FIXME - go-log
+			os.Exit(1)
+			break
+		}
+		if err == io.EOF {
+			break
+		} else if err != nil {
+		}
+	}
+
+	log.Printf("[HTTP] Loaded %d users from %s", len(users), file)
+
+	Authorised = func(u, pw string) bool {
+		hpw, ok := users[u]
+		if !ok {
+			return false
+		}
+
+		err := bcrypt.CompareHashAndPassword([]byte(hpw), []byte(pw))
+		if err != nil {
+			return false
+		}
+
+		return true
+	}
+}
+
 // Listen binds to httpBindAddr
 func Listen(httpBindAddr string, Asset func(string) ([]byte, error), exitCh chan int, registerCallback func(http.Handler)) {
 	log.Info("[HTTP] Binding to address: %s", httpBindAddr)
 
 	pat := pat.New()
 	registerCallback(pat)
 
-	err := http.ListenAndServe(httpBindAddr, pat)
+	f := func(w http.ResponseWriter, req *http.Request) {
+		if Authorised == nil {
+			pat.ServeHTTP(w, req)
+			return
+		}
+
+		u, pw, ok := req.BasicAuth()
+		if !ok || !Authorised(u, pw) {
+			w.Header().Set("WWW-Authenticate", "Basic")
+			w.WriteHeader(401)
+			return
+		}
+		pat.ServeHTTP(w, req)
+	}
+
+	err := http.ListenAndServe(httpBindAddr, http.HandlerFunc(f))
 	if err != nil {
 		log.Fatalf("[HTTP] Error binding to address %s: %s", httpBindAddr, err)
 	}