fix #793

irc/accounts.go

@@ -24,6 +24,7 @@ import (
 const (
 	keyAccountExists           = "account.exists %s"
 	keyAccountVerified         = "account.verified %s"
+	keyAccountUnregistered     = "account.unregistered %s"
 	keyAccountCallback         = "account.callback %s"
 	keyAccountVerificationCode = "account.verificationcode %s"
 	keyAccountName             = "account.name %s" // stores the 'preferred name' of the account, not casemapped
@@ -363,6 +364,7 @@ func (am *AccountManager) Register(client *Client, account string, callbackNames
 	}
 
 	accountKey := fmt.Sprintf(keyAccountExists, casefoldedAccount)
+	unregisteredKey := fmt.Sprintf(keyAccountUnregistered, casefoldedAccount)
 	accountNameKey := fmt.Sprintf(keyAccountName, casefoldedAccount)
 	callbackKey := fmt.Sprintf(keyAccountCallback, casefoldedAccount)
 	registeredTimeKey := fmt.Sprintf(keyAccountRegTime, casefoldedAccount)
@@ -401,7 +403,11 @@ func (am *AccountManager) Register(client *Client, account string, callbackNames
 		}
 
 		return am.server.store.Update(func(tx *buntdb.Tx) error {
-			_, err := am.loadRawAccount(tx, casefoldedAccount)
+			if _, err := tx.Get(unregisteredKey); err == nil {
+				return errAccountAlreadyUnregistered
+			}
+
+			_, err = am.loadRawAccount(tx, casefoldedAccount)
 			if err != errAccountDoesNotExist {
 				return errAccountAlreadyRegistered
 			}
@@ -432,7 +438,7 @@ func (am *AccountManager) Register(client *Client, account string, callbackNames
 
 	code, err := am.dispatchCallback(client, casefoldedAccount, callbackNamespace, callbackValue)
 	if err != nil {
-		am.Unregister(casefoldedAccount)
+		am.Unregister(casefoldedAccount, true)
 		return errCallbackFailed
 	} else {
 		return am.server.store.Update(func(tx *buntdb.Tx) error {
@@ -1063,7 +1069,7 @@ func (am *AccountManager) loadRawAccount(tx *buntdb.Tx, casefoldedAccount string
 	return
 }
 
-func (am *AccountManager) Unregister(account string) error {
+func (am *AccountManager) Unregister(account string, erase bool) error {
 	config := am.server.Config()
 	casefoldedAccount, err := CasefoldName(account)
 	if err != nil {
@@ -1084,6 +1090,7 @@ func (am *AccountManager) Unregister(account string) error {
 	channelsKey := fmt.Sprintf(keyAccountChannels, casefoldedAccount)
 	joinedChannelsKey := fmt.Sprintf(keyAccountJoinedChannels, casefoldedAccount)
 	lastSeenKey := fmt.Sprintf(keyAccountLastSeen, casefoldedAccount)
+	unregisteredKey := fmt.Sprintf(keyAccountUnregistered, casefoldedAccount)
 
 	var clients []*Client
 
@@ -1104,6 +1111,13 @@ func (am *AccountManager) Unregister(account string) error {
 	var accountName string
 	var channelsStr string
 	am.server.store.Update(func(tx *buntdb.Tx) error {
+		if erase {
+			tx.Delete(unregisteredKey)
+		} else {
+			if _, err := tx.Get(accountKey); err == nil {
+				tx.Set(unregisteredKey, "1", nil)
+			}
+		}
 		tx.Delete(accountKey)
 		accountName, _ = tx.Get(accountNameKey)
 		tx.Delete(accountNameKey)
@@ -1129,7 +1143,7 @@ func (am *AccountManager) Unregister(account string) error {
 
 	if err == nil {
 		var creds AccountCredentials
-		if err = json.Unmarshal([]byte(credText), &creds); err == nil {
+		if err := json.Unmarshal([]byte(credText), &creds); err == nil {
 			for _, cert := range creds.Certfps {
 				certFPKey := fmt.Sprintf(keyCertToAccount, cert)
 				am.server.store.Update(func(tx *buntdb.Tx) error {
@@ -1169,7 +1183,7 @@ func (am *AccountManager) Unregister(account string) error {
 		}
 	}
 
-	if err != nil {
+	if err != nil && !erase {
 		return errAccountDoesNotExist
 	}
 

irc/errors.go

@@ -13,6 +13,7 @@ import (
 // Runtime Errors
 var (
 	errAccountAlreadyRegistered       = errors.New(`Account already exists`)
+	errAccountAlreadyUnregistered     = errors.New(`That account name was registered previously and can't be reused`)
 	errAccountAlreadyVerified         = errors.New(`Account is already verified`)
 	errAccountCantDropPrimaryNick     = errors.New("Can't unreserve primary nickname")
 	errAccountCreation                = errors.New("Account could not be created")

irc/handlers.go

@@ -66,7 +66,7 @@ func registrationErrorToMessageAndCode(err error) (message, code string) {
 	case errAccountBadPassphrase:
 		code = "REG_INVALID_CREDENTIAL"
 		message = err.Error()
-	case errAccountAlreadyRegistered, errAccountAlreadyVerified:
+	case errAccountAlreadyRegistered, errAccountAlreadyVerified, errAccountAlreadyUnregistered:
 		message = err.Error()
 	case errAccountCreation, errAccountMustHoldNick, errAccountBadPassphrase, errCertfpAlreadyExists, errFeatureDisabled:
 		message = err.Error()

irc/nickserv.go

@@ -164,6 +164,20 @@ a code will display the necessary code.`,
 			enabled:   servCmdRequiresAuthEnabled,
 			minParams: 1,
 		},
+		"erase": {
+			handler: nsUnregisterHandler,
+			help: `Syntax: $bERASE <username> [code]$b
+
+ERASE deletes all records of an account, allowing it to be re-registered.
+This should be used with caution, because it violates an expectation that
+account names are permanent identifiers. Typically, UNREGISTER should be
+used instead. A confirmation code is required; invoking the command
+without a code will display the necessary code.`,
+			helpShort: `$bERASE$b erases all records of an account, allowing reuse.`,
+			enabled:   servCmdRequiresAuthEnabled,
+			capabs:    []string{"accreg"},
+			minParams: 1,
+		},
 		"verify": {
 			handler: nsVerifyHandler,
 			help: `Syntax: $bVERIFY <username> <code>$b
@@ -815,6 +829,8 @@ func nsSaregisterHandler(server *Server, client *Client, command string, params
 }
 
 func nsUnregisterHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {
+	erase := command == "erase"
+
 	username := params[0]
 	var verificationCode string
 	if len(params) > 1 {
@@ -826,39 +842,51 @@ func nsUnregisterHandler(server *Server, client *Client, command string, params
 		return
 	}
 
-	account, err := server.accounts.LoadAccount(username)
-	if err == errAccountDoesNotExist {
-		nsNotice(rb, client.t("Invalid account name"))
-		return
-	} else if err != nil {
-		nsNotice(rb, client.t("Internal error"))
-		return
+	var accountName string
+	var registeredAt time.Time
+	if erase {
+		// account may not be in a loadable state, e.g., if it was unregistered
+		accountName = username
+	} else {
+		account, err := server.accounts.LoadAccount(username)
+		if err == errAccountDoesNotExist {
+			nsNotice(rb, client.t("Invalid account name"))
+			return
+		} else if err != nil {
+			nsNotice(rb, client.t("Internal error"))
+			return
+		}
+		accountName = account.Name
+		registeredAt = account.RegisteredAt
 	}
 
-	cfname, _ := CasefoldName(username)
-	if !(cfname == client.Account() || client.HasRoleCapabs("accreg")) {
+	if !(accountName == client.AccountName() || client.HasRoleCapabs("accreg")) {
 		nsNotice(rb, client.t("Insufficient oper privs"))
 		return
 	}
 
-	expectedCode := utils.ConfirmationCode(account.Name, account.RegisteredAt)
+	expectedCode := utils.ConfirmationCode(accountName, registeredAt)
 	if expectedCode != verificationCode {
-		nsNotice(rb, ircfmt.Unescape(client.t("$bWarning: unregistering this account will remove its stored privileges.$b")))
-		nsNotice(rb, fmt.Sprintf(client.t("To confirm account unregistration, type: /NS UNREGISTER %[1]s %[2]s"), cfname, expectedCode))
+		if erase {
+			nsNotice(rb, ircfmt.Unescape(client.t("$bWarning: erasing this account will allow it to be re-registered; consider UNREGISTER instead.$b")))
+			nsNotice(rb, fmt.Sprintf(client.t("To confirm account erase, type: /NS ERASE %[1]s %[2]s"), accountName, expectedCode))
+		} else {
+			nsNotice(rb, ircfmt.Unescape(client.t("$bWarning: unregistering this account will remove its stored privileges.$b")))
+			nsNotice(rb, fmt.Sprintf(client.t("To confirm account unregistration, type: /NS UNREGISTER %[1]s %[2]s"), accountName, expectedCode))
+		}
 		return
 	}
 
-	err = server.accounts.Unregister(cfname)
+	err := server.accounts.Unregister(accountName, erase)
 	if err == errAccountDoesNotExist {
 		nsNotice(rb, client.t(err.Error()))
 	} else if err != nil {
 		nsNotice(rb, client.t("Error while unregistering account"))
 	} else {
-		nsNotice(rb, fmt.Sprintf(client.t("Successfully unregistered account %s"), cfname))
-		server.logger.Info("accounts", "client", client.Nick(), "unregistered account", cfname)
+		nsNotice(rb, fmt.Sprintf(client.t("Successfully unregistered account %s"), accountName))
+		server.logger.Info("accounts", "client", client.Nick(), "unregistered account", accountName)
+		client.server.snomasks.Send(sno.LocalAccounts, fmt.Sprintf(ircfmt.Unescape("Client $c[grey][$r%s$c[grey]] unregistered account $c[grey][$r%s$c[grey]]"), client.NickMaskString(), accountName))
 	}
-
-	client.server.snomasks.Send(sno.LocalAccounts, fmt.Sprintf(ircfmt.Unescape("Client $c[grey][$r%s$c[grey]] unregistered account $c[grey][$r%s$c[grey]]"), client.NickMaskString(), account.Name))
 }
 
 func nsVerifyHandler(server *Server, client *Client, command string, params []string, rb *ResponseBuffer) {