Add htpasswd support for basic auth

If the password arg starts with htpasswd=, then the rest is treated as
the file name of the htpasswd file, and used for md5 and sha1 hashes.

middleware/basicauth/basicauth.go

@@ -2,9 +2,17 @@
 package basicauth
 
 import (
+	"bufio"
 	"crypto/subtle"
+	"fmt"
+	"io"
 	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
 
+	"github.com/jimstudt/http-authentication/basic"
 	"github.com/mholt/caddy/middleware"
 )
 
@@ -37,7 +45,8 @@ func (a BasicAuth) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error
 			// Check credentials
 			if !ok ||
 				username != rule.Username ||
-				subtle.ConstantTimeCompare([]byte(password), []byte(rule.Password)) != 1 {
+				!rule.Password(password) {
+				//subtle.ConstantTimeCompare([]byte(password), []byte(rule.Password)) != 1 {
 				continue
 			}
 
@@ -64,6 +73,74 @@ func (a BasicAuth) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error
 // file or directory paths.
 type Rule struct {
 	Username  string
-	Password  string
+	Password  func(string) bool
 	Resources []string
 }
+
+type PasswordMatcher func(pw string) bool
+
+var (
+	htpasswords   map[string]map[string]PasswordMatcher
+	htpasswordsMu sync.Mutex
+)
+
+func GetHtpasswdMatcher(filename, username string) (PasswordMatcher, error) {
+	filename, err := filepath.Abs(filename)
+	if err != nil {
+		return nil, err
+	}
+	htpasswordsMu.Lock()
+	if htpasswords == nil {
+		htpasswords = make(map[string]map[string]PasswordMatcher)
+	}
+	pm := htpasswords[filename]
+	if pm == nil {
+		fh, err := os.Open(filename)
+		if err != nil {
+			return nil, fmt.Errorf("open %q: %v", filename, err)
+		}
+		defer fh.Close()
+		pm = make(map[string]PasswordMatcher)
+		if err = parseHtpasswd(pm, fh); err != nil {
+			return nil, fmt.Errorf("parsing htpasswd %q: %v", fh.Name(), err)
+		}
+		htpasswords[filename] = pm
+	}
+	htpasswordsMu.Unlock()
+	if pm[username] == nil {
+		return nil, fmt.Errorf("username %q not found in %q", username, filename)
+	}
+	return pm[username], nil
+}
+
+func parseHtpasswd(pm map[string]PasswordMatcher, r io.Reader) error {
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.IndexByte(line, '#') == 0 {
+			continue
+		}
+		i := strings.IndexByte(line, ':')
+		if i <= 0 {
+			return fmt.Errorf("malformed line, no color: %q", line)
+		}
+		user, encoded := line[:i], line[i+1:]
+		for _, p := range basic.DefaultSystems {
+			matcher, err := p(encoded)
+			if err != nil {
+				return err
+			}
+			if matcher != nil {
+				pm[user] = matcher.MatchesPassword
+				break
+			}
+		}
+	}
+	return scanner.Err()
+}
+
+func PlainMatcher(passw string) PasswordMatcher {
+	return func(pw string) bool {
+		return subtle.ConstantTimeCompare([]byte(pw), []byte(passw)) == 1
+	}
+}

middleware/basicauth/basicauth_test.go

@@ -3,8 +3,10 @@ package basicauth
 import (
 	"encoding/base64"
 	"fmt"
+	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"testing"
 
 	"github.com/mholt/caddy/middleware"
@@ -15,7 +17,7 @@ func TestBasicAuth(t *testing.T) {
 	rw := BasicAuth{
 		Next: middleware.HandlerFunc(contentHandler),
 		Rules: []Rule{
-			{Username: "test", Password: "ttest", Resources: []string{"/testing"}},
+			{Username: "test", Password: PlainMatcher("ttest"), Resources: []string{"/testing"}},
 		},
 	}
 
@@ -66,8 +68,8 @@ func TestMultipleOverlappingRules(t *testing.T) {
 	rw := BasicAuth{
 		Next: middleware.HandlerFunc(contentHandler),
 		Rules: []Rule{
-			{Username: "t", Password: "p1", Resources: []string{"/t"}},
-			{Username: "t1", Password: "p2", Resources: []string{"/t/t"}},
+			{Username: "t", Password: PlainMatcher("p1"), Resources: []string{"/t"}},
+			{Username: "t1", Password: PlainMatcher("p2"), Resources: []string{"/t/t"}},
 		},
 	}
 
@@ -111,3 +113,31 @@ func contentHandler(w http.ResponseWriter, r *http.Request) (int, error) {
 	fmt.Fprintf(w, r.URL.String())
 	return http.StatusOK, nil
 }
+
+func TestHtpasswd(t *testing.T) {
+	htpasswdPasswd := "IedFOuGmTpT8"
+	htpasswdFile := `sha1:{SHA}dcAUljwz99qFjYR0YLTXx0RqLww=
+md5:$apr1$l42y8rex$pOA2VJ0x/0TwaFeAF9nX61`
+
+	htfh, err := ioutil.TempFile("", "basicauth-")
+	if err != nil {
+		t.Skipf("Error creating temp file (%v), will skip htpassword test")
+		return
+	}
+	if _, err = htfh.Write([]byte(htpasswdFile)); err != nil {
+		t.Fatalf("write htpasswd file %q: %v", htfh.Name(), err)
+	}
+	htfh.Close()
+	defer os.Remove(htfh.Name())
+
+	for i, username := range []string{"sha1", "md5"} {
+		rule := Rule{Username: username, Resources: []string{"/testing"}}
+		if rule.Password, err = GetHtpasswdMatcher(htfh.Name(), rule.Username); err != nil {
+			t.Fatalf("GetHtpasswdMatcher(%q, %q): %v", htfh.Name(), rule.Username, err)
+		}
+		t.Logf("%d. username=%q password=%v", i, rule.Username, rule.Password)
+		if !rule.Password(htpasswdPasswd) || rule.Password(htpasswdPasswd+"!") {
+			t.Errorf("%d (%s) password does not match.", i, rule.Username)
+		}
+	}
+}