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.

config/setup/basicauth.go

 package setup
 
 import (
+	"strings"
+
 	"github.com/mholt/caddy/middleware"
 	"github.com/mholt/caddy/middleware/basicauth"
 )
@@ -23,6 +25,7 @@ func BasicAuth(c *Controller) (middleware.Middleware, error) {
 func basicAuthParse(c *Controller) ([]basicauth.Rule, error) {
 	var rules []basicauth.Rule
 
+	var err error
 	for c.Next() {
 		var rule basicauth.Rule
 
@@ -31,7 +34,10 @@ func basicAuthParse(c *Controller) ([]basicauth.Rule, error) {
 		switch len(args) {
 		case 2:
 			rule.Username = args[0]
-			rule.Password = args[1]
+			if rule.Password, err = passwordMatcher(rule.Username, args[1]); err != nil {
+				return rules, c.Errf("Get password matcher from %s: %v", c.Val(), err)
+			}
+
 			for c.NextBlock() {
 				rule.Resources = append(rule.Resources, c.Val())
 				if c.NextArg() {
@@ -41,7 +47,9 @@ func basicAuthParse(c *Controller) ([]basicauth.Rule, error) {
 		case 3:
 			rule.Resources = append(rule.Resources, args[0])
 			rule.Username = args[1]
-			rule.Password = args[2]
+			if rule.Password, err = passwordMatcher(rule.Username, args[2]); err != nil {
+				return rules, c.Errf("Get password matcher from %s: %v", c.Val(), err)
+			}
 		default:
 			return rules, c.ArgErr()
 		}
@@ -51,3 +59,11 @@ func basicAuthParse(c *Controller) ([]basicauth.Rule, error) {
 
 	return rules, nil
 }
+
+func passwordMatcher(username, passw string) (basicauth.PasswordMatcher, error) {
+	if !strings.HasPrefix(passw, "htpasswd=") {
+		return basicauth.PlainMatcher(passw), nil
+	}
+
+	return basicauth.GetHtpasswdMatcher(passw[9:], username)
+}

config/setup/basicauth_test.go

@@ -2,6 +2,9 @@ package setup
 
 import (
 	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
 	"testing"
 
 	"github.com/mholt/caddy/middleware/basicauth"
@@ -30,35 +33,57 @@ func TestBasicAuth(t *testing.T) {
 }
 
 func TestBasicAuthParse(t *testing.T) {
+	htpasswdPasswd := "IedFOuGmTpT8"
+	htpasswdFile := `sha1:{SHA}dcAUljwz99qFjYR0YLTXx0RqLww=
+md5:$apr1$l42y8rex$pOA2VJ0x/0TwaFeAF9nX61`
+
+	var skipHtpassword bool
+	htfh, err := ioutil.TempFile("", "basicauth-")
+	if err != nil {
+		t.Logf("Error creating temp file (%v), will skip htpassword test")
+		skipHtpassword = true
+	} else {
+		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())
+	}
+
 	tests := []struct {
 		input     string
 		shouldErr bool
+		password  string
 		expected  []basicauth.Rule
 	}{
-		{`basicauth user pwd`, false, []basicauth.Rule{
-			{Username: "user", Password: "pwd"},
+		{`basicauth user pwd`, false, "pwd", []basicauth.Rule{
+			{Username: "user"},
 		}},
 		{`basicauth user pwd {
-		}`, false, []basicauth.Rule{
-			{Username: "user", Password: "pwd"},
+		}`, false, "pwd", []basicauth.Rule{
+			{Username: "user"},
 		}},
 		{`basicauth user pwd {
 			/resource1
 			/resource2
-		}`, false, []basicauth.Rule{
-			{Username: "user", Password: "pwd", Resources: []string{"/resource1", "/resource2"}},
+		}`, false, "pwd", []basicauth.Rule{
+			{Username: "user", Resources: []string{"/resource1", "/resource2"}},
 		}},
-		{`basicauth /resource user pwd`, false, []basicauth.Rule{
-			{Username: "user", Password: "pwd", Resources: []string{"/resource"}},
+		{`basicauth /resource user pwd`, false, "pwd", []basicauth.Rule{
+			{Username: "user", Resources: []string{"/resource"}},
 		}},
 		{`basicauth /res1 user1 pwd1
-		  basicauth /res2 user2 pwd2`, false, []basicauth.Rule{
-			{Username: "user1", Password: "pwd1", Resources: []string{"/res1"}},
-			{Username: "user2", Password: "pwd2", Resources: []string{"/res2"}},
+		  basicauth /res2 user2 pwd2`, false, "pwd", []basicauth.Rule{
+			{Username: "user1", Resources: []string{"/res1"}},
+			{Username: "user2", Resources: []string{"/res2"}},
+		}},
+		{`basicauth user`, true, "", []basicauth.Rule{}},
+		{`basicauth`, true, "", []basicauth.Rule{}},
+		{`basicauth /resource user pwd asdf`, true, "", []basicauth.Rule{}},
+
+		{`basicauth sha1 htpasswd=` + htfh.Name(), false, htpasswdPasswd, []basicauth.Rule{
+			{Username: "sha1"},
 		}},
-		{`basicauth user`, true, []basicauth.Rule{}},
-		{`basicauth`, true, []basicauth.Rule{}},
-		{`basicauth /resource user pwd asdf`, true, []basicauth.Rule{}},
 	}
 
 	for i, test := range tests {
@@ -84,9 +109,16 @@ func TestBasicAuthParse(t *testing.T) {
 					i, j, expectedRule.Username, actualRule.Username)
 			}
 
-			if actualRule.Password != expectedRule.Password {
+			if strings.Contains(test.input, "htpasswd=") && skipHtpassword {
+				continue
+			}
+			pwd := test.password
+			if len(actual) > 1 {
+				pwd = fmt.Sprintf("%s%d", pwd, j+1)
+			}
+			if !actualRule.Password(pwd) || actualRule.Password(test.password+"!") {
 				t.Errorf("Test %d, rule %d: Expected password '%s', got '%s'",
-					i, j, expectedRule.Password, actualRule.Password)
+					i, j, test.password, actualRule.Password)
 			}
 
 			expectedRes := fmt.Sprintf("%v", expectedRule.Resources)

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)
+		}
+	}
+}