Add loader for static users

pkg/authentication/basic/static_users.go

@@ -0,0 +1,74 @@
+package basic
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/apis/options"
+	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/logger"
+)
+
+func LoadStaticUsers(opts options.StaticUsers) (map[string]options.StaticUser, error) {
+	switch {
+	case opts.FromHTPasswdFile != "" && opts.FromFile == "" && len(opts.Users) == 0:
+		return loadStaticUsersFromHTPasswdFile(opts.FromHTPasswdFile, opts.HTPasswdUserGroups)
+	case opts.FromHTPasswdFile == "" && opts.FromFile != "" && len(opts.Users) == 0:
+		return loadStaticUsersFromFile(opts.FromFile)
+	case opts.FromHTPasswdFile == "" && opts.FromFile == "" && len(opts.Users) > 0:
+		return loadStaticUsersInline(opts.Users)
+	default:
+		return nil, errors.New("exactly one of HTPasswdFile, FromFile and Users must be specified")
+	}
+}
+
+func loadStaticUsersFromHTPasswdFile(path string, userGroups []string) (map[string]options.StaticUser, error) {
+	// We allow HTPasswd location via config options
+	r, err := os.Open(path) // #nosec G304
+	if err != nil {
+		return nil, fmt.Errorf("could not open htpasswd file: %v", err)
+	}
+	defer func(c io.Closer) {
+		cerr := c.Close()
+		if cerr != nil {
+			logger.Fatalf("error closing the htpasswd file: %v", cerr)
+		}
+	}(r)
+
+	passwdMap, err := newHtpasswd(r)
+	if err != nil {
+		return nil, fmt.Errorf("could not load read htpasswd file: %v", err)
+	}
+
+	users := make(map[string]options.StaticUser)
+	for user, pass := range passwdMap.users {
+		users[user] = options.StaticUser{
+			Username: user,
+			Password: pass.(string),
+			Groups:   append([]string{}, userGroups...),
+		}
+	}
+	return users, nil
+}
+
+func loadStaticUsersFromFile(path string) (map[string]options.StaticUser, error) {
+	users := []options.StaticUser{}
+	if err := options.LoadYAML(path, &users); err != nil {
+		return nil, fmt.Errorf("could not load static user file: %v", err)
+	}
+
+	return loadStaticUsersInline(users)
+}
+
+func loadStaticUsersInline(inlineUsers []options.StaticUser) (map[string]options.StaticUser, error) {
+	users := make(map[string]options.StaticUser)
+	for _, user := range inlineUsers {
+		if _, ok := users[user.Username]; ok {
+			return nil, fmt.Errorf("static user %q provided multiple times", user.Username)
+		}
+		users[user.Username] = user
+	}
+
+	return users, nil
+}