open-vault/plugins/database/mssql/mssql.go

398 lines
10 KiB
Go

package mssql
import (
"context"
"database/sql"
"errors"
"fmt"
"strings"
_ "github.com/denisenkom/go-mssqldb"
multierror "github.com/hashicorp/go-multierror"
dbplugin "github.com/hashicorp/vault/sdk/database/dbplugin/v5"
"github.com/hashicorp/vault/sdk/database/helper/connutil"
"github.com/hashicorp/vault/sdk/database/helper/dbutil"
"github.com/hashicorp/vault/sdk/helper/dbtxn"
"github.com/hashicorp/vault/sdk/helper/strutil"
"github.com/hashicorp/vault/sdk/helper/template"
)
const (
msSQLTypeName = "mssql"
defaultUserNameTemplate = `{{ printf "v-%s-%s-%s-%s" (.DisplayName | truncate 20) (.RoleName | truncate 20) (random 20) (unix_time) | truncate 128 }}`
)
var _ dbplugin.Database = &MSSQL{}
// MSSQL is an implementation of Database interface
type MSSQL struct {
*connutil.SQLConnectionProducer
usernameProducer template.StringTemplate
}
func New() (interface{}, error) {
db := new()
// Wrap the plugin with middleware to sanitize errors
dbType := dbplugin.NewDatabaseErrorSanitizerMiddleware(db, db.secretValues)
return dbType, nil
}
func new() *MSSQL {
connProducer := &connutil.SQLConnectionProducer{}
connProducer.Type = msSQLTypeName
return &MSSQL{
SQLConnectionProducer: connProducer,
}
}
// Type returns the TypeName for this backend
func (m *MSSQL) Type() (string, error) {
return msSQLTypeName, nil
}
func (m *MSSQL) secretValues() map[string]string {
return map[string]string{
m.Password: "[password]",
}
}
func (m *MSSQL) getConnection(ctx context.Context) (*sql.DB, error) {
db, err := m.Connection(ctx)
if err != nil {
return nil, err
}
return db.(*sql.DB), nil
}
func (m *MSSQL) Initialize(ctx context.Context, req dbplugin.InitializeRequest) (dbplugin.InitializeResponse, error) {
newConf, err := m.SQLConnectionProducer.Init(ctx, req.Config, req.VerifyConnection)
if err != nil {
return dbplugin.InitializeResponse{}, err
}
usernameTemplate, err := strutil.GetString(req.Config, "username_template")
if err != nil {
return dbplugin.InitializeResponse{}, fmt.Errorf("failed to retrieve username_template: %w", err)
}
if usernameTemplate == "" {
usernameTemplate = defaultUserNameTemplate
}
up, err := template.NewTemplate(template.Template(usernameTemplate))
if err != nil {
return dbplugin.InitializeResponse{}, fmt.Errorf("unable to initialize username template: %w", err)
}
m.usernameProducer = up
_, err = m.usernameProducer.Generate(dbplugin.UsernameMetadata{})
if err != nil {
return dbplugin.InitializeResponse{}, fmt.Errorf("invalid username template - did you reference a field that isn't available? : %w", err)
}
resp := dbplugin.InitializeResponse{
Config: newConf,
}
return resp, nil
}
// NewUser generates the username/password on the underlying MSSQL secret backend as instructed by
// the statements provided.
func (m *MSSQL) NewUser(ctx context.Context, req dbplugin.NewUserRequest) (dbplugin.NewUserResponse, error) {
m.Lock()
defer m.Unlock()
db, err := m.getConnection(ctx)
if err != nil {
return dbplugin.NewUserResponse{}, fmt.Errorf("unable to get connection: %w", err)
}
if len(req.Statements.Commands) == 0 {
return dbplugin.NewUserResponse{}, dbutil.ErrEmptyCreationStatement
}
username, err := m.usernameProducer.Generate(req.UsernameConfig)
if err != nil {
return dbplugin.NewUserResponse{}, err
}
expirationStr := req.Expiration.Format("2006-01-02 15:04:05-0700")
tx, err := db.BeginTx(ctx, nil)
if err != nil {
return dbplugin.NewUserResponse{}, err
}
defer tx.Rollback()
for _, stmt := range req.Statements.Commands {
for _, query := range strutil.ParseArbitraryStringSlice(stmt, ";") {
query = strings.TrimSpace(query)
if len(query) == 0 {
continue
}
m := map[string]string{
"name": username,
"password": req.Password,
"expiration": expirationStr,
}
if err := dbtxn.ExecuteTxQuery(ctx, tx, m, query); err != nil {
return dbplugin.NewUserResponse{}, err
}
}
}
if err := tx.Commit(); err != nil {
return dbplugin.NewUserResponse{}, err
}
resp := dbplugin.NewUserResponse{
Username: username,
}
return resp, nil
}
// DeleteUser attempts to drop the specified user. It will first attempt to disable login,
// then kill pending connections from that user, and finally drop the user and login from the
// database instance.
func (m *MSSQL) DeleteUser(ctx context.Context, req dbplugin.DeleteUserRequest) (dbplugin.DeleteUserResponse, error) {
if len(req.Statements.Commands) == 0 {
err := m.revokeUserDefault(ctx, req.Username)
return dbplugin.DeleteUserResponse{}, err
}
db, err := m.getConnection(ctx)
if err != nil {
return dbplugin.DeleteUserResponse{}, fmt.Errorf("unable to get connection: %w", err)
}
merr := &multierror.Error{}
// Execute each query
for _, stmt := range req.Statements.Commands {
for _, query := range strutil.ParseArbitraryStringSlice(stmt, ";") {
query = strings.TrimSpace(query)
if len(query) == 0 {
continue
}
m := map[string]string{
"name": req.Username,
}
if err := dbtxn.ExecuteDBQuery(ctx, db, m, query); err != nil {
merr = multierror.Append(merr, err)
}
}
}
return dbplugin.DeleteUserResponse{}, merr.ErrorOrNil()
}
func (m *MSSQL) revokeUserDefault(ctx context.Context, username string) error {
// Get connection
db, err := m.getConnection(ctx)
if err != nil {
return err
}
// First disable server login
disableStmt, err := db.PrepareContext(ctx, fmt.Sprintf("ALTER LOGIN [%s] DISABLE;", username))
if err != nil {
return err
}
defer disableStmt.Close()
if _, err := disableStmt.ExecContext(ctx); err != nil {
return err
}
// Query for sessions for the login so that we can kill any outstanding
// sessions. There cannot be any active sessions before we drop the logins
// This isn't done in a transaction because even if we fail along the way,
// we want to remove as much access as possible
sessionStmt, err := db.PrepareContext(ctx,
"SELECT session_id FROM sys.dm_exec_sessions WHERE login_name = @p1;")
if err != nil {
return err
}
defer sessionStmt.Close()
sessionRows, err := sessionStmt.QueryContext(ctx, username)
if err != nil {
return err
}
defer sessionRows.Close()
var revokeStmts []string
for sessionRows.Next() {
var sessionID int
err = sessionRows.Scan(&sessionID)
if err != nil {
return err
}
revokeStmts = append(revokeStmts, fmt.Sprintf("KILL %d;", sessionID))
}
// Query for database users using undocumented stored procedure for now since
// it is the easiest way to get this information;
// we need to drop the database users before we can drop the login and the role
// This isn't done in a transaction because even if we fail along the way,
// we want to remove as much access as possible
stmt, err := db.PrepareContext(ctx, "EXEC master.dbo.sp_msloginmappings @p1;")
if err != nil {
return err
}
defer stmt.Close()
rows, err := stmt.QueryContext(ctx, username)
if err != nil {
return err
}
defer rows.Close()
for rows.Next() {
var loginName, dbName, qUsername, aliasName sql.NullString
err = rows.Scan(&loginName, &dbName, &qUsername, &aliasName)
if err != nil {
return err
}
if !dbName.Valid {
continue
}
revokeStmts = append(revokeStmts, fmt.Sprintf(dropUserSQL, dbName.String, username, username))
}
// we do not stop on error, as we want to remove as
// many permissions as possible right now
var lastStmtError error
for _, query := range revokeStmts {
if err := dbtxn.ExecuteDBQuery(ctx, db, nil, query); err != nil {
lastStmtError = err
}
}
// can't drop if not all database users are dropped
if rows.Err() != nil {
return fmt.Errorf("could not generate sql statements for all rows: %w", rows.Err())
}
if lastStmtError != nil {
return fmt.Errorf("could not perform all sql statements: %w", lastStmtError)
}
// Drop this login
stmt, err = db.PrepareContext(ctx, fmt.Sprintf(dropLoginSQL, username, username))
if err != nil {
return err
}
defer stmt.Close()
if _, err := stmt.ExecContext(ctx); err != nil {
return err
}
return nil
}
func (m *MSSQL) UpdateUser(ctx context.Context, req dbplugin.UpdateUserRequest) (dbplugin.UpdateUserResponse, error) {
if req.Password == nil && req.Expiration == nil {
return dbplugin.UpdateUserResponse{}, fmt.Errorf("no changes requested")
}
if req.Password != nil {
err := m.updateUserPass(ctx, req.Username, req.Password)
return dbplugin.UpdateUserResponse{}, err
}
// Expiration is a no-op
return dbplugin.UpdateUserResponse{}, nil
}
func (m *MSSQL) updateUserPass(ctx context.Context, username string, changePass *dbplugin.ChangePassword) error {
stmts := changePass.Statements.Commands
if len(stmts) == 0 {
stmts = []string{alterLoginSQL}
}
password := changePass.NewPassword
if username == "" || password == "" {
return errors.New("must provide both username and password")
}
m.Lock()
defer m.Unlock()
db, err := m.getConnection(ctx)
if err != nil {
return err
}
var exists bool
err = db.QueryRowContext(ctx, "SELECT 1 FROM master.sys.server_principals where name = N'$1'", username).Scan(&exists)
if err != nil && err != sql.ErrNoRows {
return err
}
tx, err := db.BeginTx(ctx, nil)
if err != nil {
return err
}
defer func() {
_ = tx.Rollback()
}()
for _, stmt := range stmts {
for _, query := range strutil.ParseArbitraryStringSlice(stmt, ";") {
query = strings.TrimSpace(query)
if len(query) == 0 {
continue
}
m := map[string]string{
"name": username,
"username": username,
"password": password,
}
if err := dbtxn.ExecuteTxQuery(ctx, tx, m, query); err != nil {
return fmt.Errorf("failed to execute query: %w", err)
}
}
}
if err := tx.Commit(); err != nil {
return fmt.Errorf("failed to commit transaction: %w", err)
}
return nil
}
const dropUserSQL = `
USE [%s]
IF EXISTS
(SELECT name
FROM sys.database_principals
WHERE name = N'%s')
BEGIN
DROP USER [%s]
END
`
const dropLoginSQL = `
IF EXISTS
(SELECT name
FROM master.sys.server_principals
WHERE name = N'%s')
BEGIN
DROP LOGIN [%s]
END
`
const alterLoginSQL = `
ALTER LOGIN [{{username}}] WITH PASSWORD = '{{password}}'
`