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

296 lines
7.2 KiB
Go

package hana
import (
"context"
"database/sql"
"errors"
"fmt"
"strings"
"time"
_ "github.com/SAP/go-hdb/driver"
"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 (
hanaTypeName = "hdb"
)
// HANA is an implementation of Database interface
type HANA struct {
*connutil.SQLConnectionProducer
credsutil.CredentialsProducer
}
var _ dbplugin.Database = &HANA{}
// New implements builtinplugins.BuiltinFactory
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() *HANA {
connProducer := &connutil.SQLConnectionProducer{}
connProducer.Type = hanaTypeName
credsProducer := &credsutil.SQLCredentialsProducer{
DisplayNameLen: 32,
RoleNameLen: 20,
UsernameLen: 128,
Separator: "_",
}
return &HANA{
SQLConnectionProducer: connProducer,
CredentialsProducer: credsProducer,
}
}
// Run instantiates a HANA 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 (h *HANA) Type() (string, error) {
return hanaTypeName, nil
}
func (h *HANA) getConnection(ctx context.Context) (*sql.DB, error) {
db, err := h.Connection(ctx)
if err != nil {
return nil, err
}
return db.(*sql.DB), nil
}
// CreateUser generates the username/password on the underlying HANA secret backend
// as instructed by the CreationStatement provided.
func (h *HANA) CreateUser(ctx context.Context, statements dbplugin.Statements, usernameConfig dbplugin.UsernameConfig, expiration time.Time) (username string, password string, err error) {
// Grab the lock
h.Lock()
defer h.Unlock()
statements = dbutil.StatementCompatibilityHelper(statements)
// Get the connection
db, err := h.getConnection(ctx)
if err != nil {
return "", "", err
}
if len(statements.Creation) == 0 {
return "", "", dbutil.ErrEmptyCreationStatement
}
// Generate username
username, err = h.GenerateUsername(usernameConfig)
if err != nil {
return "", "", err
}
// HANA does not allow hyphens in usernames, and highly prefers capital letters
username = strings.Replace(username, "-", "_", -1)
username = strings.ToUpper(username)
// Generate password
password, err = h.GeneratePassword()
if err != nil {
return "", "", err
}
// Most HANA configurations have password constraints
// Prefix with A1a to satisfy these constraints. User will be forced to change upon login
password = strings.Replace(password, "-", "_", -1)
password = "A1a" + password
// If expiration is in the role SQL, HANA will deactivate the user when time is up,
// regardless of whether vault is alive to revoke lease
expirationStr, err := h.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
}
// Renewing hana user just means altering user's valid until property
func (h *HANA) RenewUser(ctx context.Context, statements dbplugin.Statements, username string, expiration time.Time) error {
statements = dbutil.StatementCompatibilityHelper(statements)
// Get connection
db, err := h.getConnection(ctx)
if err != nil {
return err
}
// Start a transaction
tx, err := db.BeginTx(ctx, nil)
if err != nil {
return err
}
defer tx.Rollback()
// If expiration is in the role SQL, HANA will deactivate the user when time is up,
// regardless of whether vault is alive to revoke lease
expirationStr, err := h.GenerateExpiration(expiration)
if err != nil {
return err
}
// Renew user's valid until property field
stmt, err := tx.PrepareContext(ctx, "ALTER USER "+username+" VALID UNTIL "+"'"+expirationStr+"'")
if err != nil {
return err
}
defer stmt.Close()
if _, err := stmt.ExecContext(ctx); err != nil {
return err
}
// Commit the transaction
if err := tx.Commit(); err != nil {
return err
}
return nil
}
// Revoking hana user will deactivate user and try to perform a soft drop
func (h *HANA) RevokeUser(ctx context.Context, statements dbplugin.Statements, username string) error {
statements = dbutil.StatementCompatibilityHelper(statements)
// default revoke will be a soft drop on user
if len(statements.Revocation) == 0 {
return h.revokeUserDefault(ctx, username)
}
// Get connection
db, err := h.getConnection(ctx)
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.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.ExecuteTxQuery(ctx, tx, m, query); err != nil {
return err
}
}
}
return tx.Commit()
}
func (h *HANA) revokeUserDefault(ctx context.Context, username string) error {
// Get connection
db, err := h.getConnection(ctx)
if err != nil {
return err
}
// Start a transaction
tx, err := db.BeginTx(ctx, nil)
if err != nil {
return err
}
defer tx.Rollback()
// Disable server login for user
disableStmt, err := tx.PrepareContext(ctx, fmt.Sprintf("ALTER USER %s DEACTIVATE USER NOW", username))
if err != nil {
return err
}
defer disableStmt.Close()
if _, err := disableStmt.ExecContext(ctx); err != nil {
return err
}
// Invalidates current sessions and performs soft drop (drop if no dependencies)
// if hard drop is desired, custom revoke statements should be written for role
dropStmt, err := tx.PrepareContext(ctx, fmt.Sprintf("DROP USER %s RESTRICT", username))
if err != nil {
return err
}
defer dropStmt.Close()
if _, err := dropStmt.ExecContext(ctx); err != nil {
return err
}
// Commit transaction
if err := tx.Commit(); err != nil {
return err
}
return nil
}
// RotateRootCredentials is not currently supported on HANA
func (h *HANA) RotateRootCredentials(ctx context.Context, statements []string) (map[string]interface{}, error) {
return nil, errors.New("root credentaion rotation is not currently implemented in this database secrets engine")
}