package http import (	"bytes"	"html/template"	"log" 	"github.com/rclone/rclone/fs/config/flags"	"github.com/spf13/pflag") // AuthHelp returns text describing the http authentication to add to the command help.func AuthHelp(prefix string) string {	help := `#### Authentication By default this will serve files without needing a login. You can either use an htpasswd file which can take lots of users, orset a single username and password with the ` + "`--{{ .Prefix }}user` and `--{{ .Prefix }}pass`" + ` flags. If no static users are configured by either of the above methods, and clientcertificates are required by the ` + "`--client-ca`" + ` flag passed to the server, theclient certificate common name will be considered as the username. Use ` + "`--{{ .Prefix }}htpasswd /path/to/htpasswd`" + ` to provide an htpasswd file.  This isin standard apache format and supports MD5, SHA1 and BCrypt for basicauthentication.  Bcrypt is recommended. To create an htpasswd file:     touch htpasswd    htpasswd -B htpasswd user    htpasswd -B htpasswd anotherUser The password file can be updated while rclone is running. Use ` + "`--{{ .Prefix }}realm`" + ` to set the authentication realm. Use ` + "`--{{ .Prefix }}salt`" + ` to change the password hashing salt from the default.`	tmpl, err := template.New("auth help").Parse(help)	if err != nil {		log.Fatal("Fatal error parsing template", err)	} 	data := struct {		Prefix string	}{		Prefix: prefix,	}	buf := &bytes.Buffer{}	err = tmpl.Execute(buf, data)	if err != nil {		log.Fatal("Fatal error executing template", err)	}	return buf.String()} // CustomAuthFn if used will be used to authenticate user, pass. If an error// is returned then the user is not authenticated.//// If a non nil value is returned then it is added to the context under the keytype CustomAuthFn func(user, pass string) (value interface{}, err error) // AuthConfig contains options for the http authenticationtype AuthConfig struct {	HtPasswd     string       // htpasswd file - if not provided no authentication is done	Realm        string       // realm for authentication	BasicUser    string       // single username for basic auth if not using Htpasswd	BasicPass    string       // password for BasicUser	Salt         string       // password hashing salt	CustomAuthFn CustomAuthFn `json:"-"` // custom Auth (not set by command line flags)} // AddFlagsPrefix adds flags to the flag set for AuthConfigfunc (cfg *AuthConfig) AddFlagsPrefix(flagSet *pflag.FlagSet, prefix string) {	flags.StringVarP(flagSet, &cfg.HtPasswd, prefix+"htpasswd", "", cfg.HtPasswd, "A htpasswd file - if not provided no authentication is done")	flags.StringVarP(flagSet, &cfg.Realm, prefix+"realm", "", cfg.Realm, "Realm for authentication")	flags.StringVarP(flagSet, &cfg.BasicUser, prefix+"user", "", cfg.BasicUser, "User name for authentication")	flags.StringVarP(flagSet, &cfg.BasicPass, prefix+"pass", "", cfg.BasicPass, "Password for authentication")	flags.StringVarP(flagSet, &cfg.Salt, prefix+"salt", "", cfg.Salt, "Password hashing salt")} // AddAuthFlagsPrefix adds flags to the flag set for AuthConfigfunc AddAuthFlagsPrefix(flagSet *pflag.FlagSet, prefix string, cfg *AuthConfig) {	cfg.AddFlagsPrefix(flagSet, prefix)} // DefaultAuthCfg returns a new config which can be customized by command line flagsfunc DefaultAuthCfg() AuthConfig {	return AuthConfig{		Salt: "dlPL2MqE",	}}