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

384 lines
8.9 KiB
Go

package mssql
import (
"context"
"database/sql"
"errors"
"fmt"
"strings"
"time"
_ "github.com/denisenkom/go-mssqldb"
"github.com/hashicorp/errwrap"
multierror "github.com/hashicorp/go-multierror"
"github.com/hashicorp/vault/api"
"github.com/hashicorp/vault/sdk/database/dbplugin"
"github.com/hashicorp/vault/sdk/database/helper/connutil"
"github.com/hashicorp/vault/sdk/database/helper/credsutil"
"github.com/hashicorp/vault/sdk/database/helper/dbutil"
"github.com/hashicorp/vault/sdk/helper/dbtxn"
"github.com/hashicorp/vault/sdk/helper/strutil"
)
const msSQLTypeName = "mssql"
var _ dbplugin.Database = &MSSQL{}
// MSSQL is an implementation of Database interface
type MSSQL struct {
*connutil.SQLConnectionProducer
credsutil.CredentialsProducer
}
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
credsProducer := &credsutil.SQLCredentialsProducer{
DisplayNameLen: 20,
RoleNameLen: 20,
UsernameLen: 128,
Separator: "-",
}
return &MSSQL{
SQLConnectionProducer: connProducer,
CredentialsProducer: credsProducer,
}
}
// Run instantiates a MSSQL object, and runs the RPC server for the plugin
func Run(apiTLSConfig *api.TLSConfig) error {
dbType, err := New()
if err != nil {
return err
}
dbplugin.Serve(dbType.(dbplugin.Database), api.VaultPluginTLSProvider(apiTLSConfig))
return nil
}
// Type returns the TypeName for this backend
func (m *MSSQL) Type() (string, error) {
return msSQLTypeName, nil
}
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
}
// CreateUser generates the username/password on the underlying MSSQL secret backend as instructed by
// the CreationStatement provided.
func (m *MSSQL) CreateUser(ctx context.Context, statements dbplugin.Statements, usernameConfig dbplugin.UsernameConfig, expiration time.Time) (username string, password string, err error) {
// Grab the lock
m.Lock()
defer m.Unlock()
statements = dbutil.StatementCompatibilityHelper(statements)
// Get the connection
db, err := m.getConnection(ctx)
if err != nil {
return "", "", err
}
if len(statements.Creation) == 0 {
return "", "", dbutil.ErrEmptyCreationStatement
}
username, err = m.GenerateUsername(usernameConfig)
if err != nil {
return "", "", err
}
password, err = m.GeneratePassword()
if err != nil {
return "", "", err
}
expirationStr, err := m.GenerateExpiration(expiration)
if err != nil {
return "", "", err
}
// Start a transaction
tx, err := db.BeginTx(ctx, nil)
if err != nil {
return "", "", err
}
defer tx.Rollback()
// Execute each query
for _, stmt := range statements.Creation {
for _, query := range strutil.ParseArbitraryStringSlice(stmt, ";") {
query = strings.TrimSpace(query)
if len(query) == 0 {
continue
}
m := map[string]string{
"name": username,
"password": password,
"expiration": expirationStr,
}
if err := dbtxn.ExecuteTxQuery(ctx, tx, m, query); err != nil {
return "", "", err
}
}
}
// Commit the transaction
if err := tx.Commit(); err != nil {
return "", "", err
}
return username, password, nil
}
// RenewUser is not supported on MSSQL, so this is a no-op.
func (m *MSSQL) RenewUser(ctx context.Context, statements dbplugin.Statements, username string, expiration time.Time) error {
// NOOP
return nil
}
// RevokeUser 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) RevokeUser(ctx context.Context, statements dbplugin.Statements, username string) error {
statements = dbutil.StatementCompatibilityHelper(statements)
if len(statements.Revocation) == 0 {
return m.revokeUserDefault(ctx, username)
}
// Get connection
db, err := m.getConnection(ctx)
if err != nil {
return err
}
var result error
// Execute each query
for _, stmt := range statements.Revocation {
for _, query := range strutil.ParseArbitraryStringSlice(stmt, ";") {
query = strings.TrimSpace(query)
if len(query) == 0 {
continue
}
m := map[string]string{
"name": username,
}
if err := dbtxn.ExecuteDBQuery(ctx, db, m, query); err != nil {
result = multierror.Append(result, err)
}
}
}
return result
}
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 errwrap.Wrapf("could not generate sql statements for all rows: {{err}}", rows.Err())
}
if lastStmtError != nil {
return errwrap.Wrapf("could not perform all sql statements: {{err}}", 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) RotateRootCredentials(ctx context.Context, statements []string) (map[string]interface{}, error) {
m.Lock()
defer m.Unlock()
if len(m.Username) == 0 || len(m.Password) == 0 {
return nil, errors.New("username and password are required to rotate")
}
rotateStatents := statements
if len(rotateStatents) == 0 {
rotateStatents = []string{rotateRootCredentialsSQL}
}
db, err := m.getConnection(ctx)
if err != nil {
return nil, err
}
tx, err := db.BeginTx(ctx, nil)
if err != nil {
return nil, err
}
defer func() {
tx.Rollback()
}()
password, err := m.GeneratePassword()
if err != nil {
return nil, err
}
for _, stmt := range rotateStatents {
for _, query := range strutil.ParseArbitraryStringSlice(stmt, ";") {
query = strings.TrimSpace(query)
if len(query) == 0 {
continue
}
m := map[string]string{
"username": m.Username,
"password": password,
}
if err := dbtxn.ExecuteTxQuery(ctx, tx, m, query); err != nil {
return nil, err
}
}
}
if err := tx.Commit(); err != nil {
return nil, err
}
if err := db.Close(); err != nil {
return nil, err
}
m.RawConfig["password"] = password
return m.RawConfig, 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 rotateRootCredentialsSQL = `
ALTER LOGIN [{{username}}] WITH PASSWORD = '{{password}}'
`