-
Notifications
You must be signed in to change notification settings - Fork 4.2k
/
redshift.go
480 lines (410 loc) · 13.7 KB
/
redshift.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
package redshift
import (
"context"
"database/sql"
"errors"
"fmt"
"strings"
"github.com/hashicorp/go-multierror"
"github.com/hashicorp/go-secure-stdlib/strutil"
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/template"
"github.com/lib/pq"
)
const (
// This is how this plugin will be reflected in middleware
// such as metrics.
middlewareTypeName = "redshift"
// This allows us to use the postgres database driver.
sqlTypeName = "postgres"
defaultRenewSQL = `
ALTER USER "{{name}}" VALID UNTIL '{{expiration}}';
`
defaultRotateRootCredentialsSQL = `
ALTER USER "{{name}}" WITH PASSWORD '{{password}}';
`
defaultUserNameTemplate = `{{ printf "v-%s-%s-%s-%s" (.DisplayName | truncate 8) (.RoleName | truncate 8) (random 20) (unix_time) | truncate 63 | lowercase }}`
)
var _ dbplugin.Database = (*RedShift)(nil)
// New implements builtinplugins.BuiltinFactory
// Redshift implements (mostly) a postgres 8 interface, and part of that is
// under the hood, it's lower-casing the usernames.
func New() (interface{}, error) {
db := newRedshift()
// Wrap the plugin with middleware to sanitize errors
dbType := dbplugin.NewDatabaseErrorSanitizerMiddleware(db, db.secretValues)
return dbType, nil
}
func newRedshift() *RedShift {
connProducer := &connutil.SQLConnectionProducer{}
connProducer.Type = sqlTypeName
db := &RedShift{
SQLConnectionProducer: connProducer,
}
return db
}
type RedShift struct {
*connutil.SQLConnectionProducer
usernameProducer template.StringTemplate
}
func (r *RedShift) secretValues() map[string]string {
return map[string]string{
r.Password: "[password]",
}
}
func (r *RedShift) Type() (string, error) {
return middlewareTypeName, nil
}
// Initialize must be called on each new RedShift struct before use.
// It uses the connutil.SQLConnectionProducer's Init function to do all the lifting.
func (r *RedShift) Initialize(ctx context.Context, req dbplugin.InitializeRequest) (dbplugin.InitializeResponse, error) {
conf, err := r.Init(ctx, req.Config, req.VerifyConnection)
if err != nil {
return dbplugin.InitializeResponse{}, fmt.Errorf("error initializing db: %w", 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)
}
r.usernameProducer = up
_, err = r.usernameProducer.Generate(dbplugin.UsernameMetadata{})
if err != nil {
return dbplugin.InitializeResponse{}, fmt.Errorf("invalid username template: %w", err)
}
return dbplugin.InitializeResponse{
Config: conf,
}, nil
}
// getConnection accepts a context and returns a new pointer to a sql.DB object.
// It's up to the caller to close the connection or handle reuse logic.
func (r *RedShift) getConnection(ctx context.Context) (*sql.DB, error) {
db, err := r.Connection(ctx)
if err != nil {
return nil, err
}
return db.(*sql.DB), nil
}
// NewUser creates a new user in the database. There is no default statement for
// creating users, so one must be specified in the plugin config.
// Generated usernames are of the form v-{display-name}-{role-name}-{UUID}-{timestamp}
func (r *RedShift) NewUser(ctx context.Context, req dbplugin.NewUserRequest) (dbplugin.NewUserResponse, error) {
if len(req.Statements.Commands) == 0 {
return dbplugin.NewUserResponse{}, dbutil.ErrEmptyCreationStatement
}
// Grab the lock
r.Lock()
defer r.Unlock()
username, err := r.usernameProducer.Generate(req.UsernameConfig)
if err != nil {
return dbplugin.NewUserResponse{}, err
}
password := req.Password
expirationStr := req.Expiration.Format("2006-01-02 15:04:05-0700")
// Get the connection
db, err := r.getConnection(ctx)
if err != nil {
return dbplugin.NewUserResponse{}, err
}
defer db.Close()
// Start a transaction
tx, err := db.BeginTx(ctx, nil)
if err != nil {
return dbplugin.NewUserResponse{}, err
}
defer func() {
tx.Rollback()
}()
// 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": username,
"username": username,
"password": password,
"expiration": expirationStr,
}
if err := dbtxn.ExecuteTxQuery(ctx, tx, m, query); err != nil {
return dbplugin.NewUserResponse{}, err
}
}
}
// Commit the transaction
if err := tx.Commit(); err != nil {
return dbplugin.NewUserResponse{}, err
}
return dbplugin.NewUserResponse{
Username: username,
}, nil
}
// UpdateUser can update the expiration or the password of a user, or both.
// The updates all happen in a single transaction, so they will either all
// succeed or all fail.
// Both updates support both default and custom statements.
func (r *RedShift) UpdateUser(ctx context.Context, req dbplugin.UpdateUserRequest) (dbplugin.UpdateUserResponse, error) {
if req.Password == nil && req.Expiration == nil {
return dbplugin.UpdateUserResponse{}, errors.New("no changes requested")
}
r.Lock()
defer r.Unlock()
db, err := r.getConnection(ctx)
if err != nil {
return dbplugin.UpdateUserResponse{}, err
}
defer db.Close()
tx, err := db.BeginTx(ctx, nil)
if err != nil {
return dbplugin.UpdateUserResponse{}, err
}
defer func() {
tx.Rollback()
}()
if req.Expiration != nil {
err = updateUserExpiration(ctx, req, tx)
if err != nil {
return dbplugin.UpdateUserResponse{}, err
}
}
if req.Password != nil {
err = updateUserPassword(ctx, req, tx)
if err != nil {
return dbplugin.UpdateUserResponse{}, err
}
}
err = tx.Commit()
return dbplugin.UpdateUserResponse{}, err
}
func updateUserExpiration(ctx context.Context, req dbplugin.UpdateUserRequest, tx *sql.Tx) error {
if req.Username == "" {
return errors.New("must provide a username to update user expiration")
}
renewStmts := req.Expiration.Statements
if len(renewStmts.Commands) == 0 {
renewStmts.Commands = []string{defaultRenewSQL}
}
expirationStr := req.Expiration.NewExpiration.Format("2006-01-02 15:04:05-0700")
for _, stmt := range renewStmts.Commands {
for _, query := range strutil.ParseArbitraryStringSlice(stmt, ";") {
query = strings.TrimSpace(query)
if len(query) == 0 {
continue
}
m := map[string]string{
"name": req.Username,
"username": req.Username,
"expiration": expirationStr,
}
if err := dbtxn.ExecuteTxQuery(ctx, tx, m, query); err != nil {
return err
}
}
}
return nil
}
func updateUserPassword(ctx context.Context, req dbplugin.UpdateUserRequest, tx *sql.Tx) error {
username := req.Username
password := req.Password.NewPassword
if username == "" || password == "" {
return errors.New("must provide both username and a new password to update user password")
}
// Check if the role exists
var exists bool
err := tx.QueryRowContext(ctx, "SELECT exists (SELECT usename FROM pg_user WHERE usename=$1);", username).Scan(&exists)
if err != nil && err != sql.ErrNoRows {
// Server error
return err
}
if err == sql.ErrNoRows || !exists {
// Most likely a user error
return fmt.Errorf("cannot update password for username %q because it does not exist", username)
}
// Vault requires the database user already exist, and that the credentials
// used to execute the rotation statements has sufficient privileges.
statements := req.Password.Statements.Commands
if len(statements) == 0 {
statements = []string{defaultRotateRootCredentialsSQL}
}
// Execute each query
for _, stmt := range statements {
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 err
}
}
}
return nil
}
// DeleteUser supports both default and custom statements to delete a user.
func (r *RedShift) DeleteUser(ctx context.Context, req dbplugin.DeleteUserRequest) (dbplugin.DeleteUserResponse, error) {
// Grab the lock
r.Lock()
defer r.Unlock()
if len(req.Statements.Commands) == 0 {
return r.defaultDeleteUser(ctx, req)
}
return r.customDeleteUser(ctx, req)
}
func (r *RedShift) customDeleteUser(ctx context.Context, req dbplugin.DeleteUserRequest) (dbplugin.DeleteUserResponse, error) {
db, err := r.getConnection(ctx)
if err != nil {
return dbplugin.DeleteUserResponse{}, err
}
defer db.Close()
tx, err := db.BeginTx(ctx, nil)
if err != nil {
return dbplugin.DeleteUserResponse{}, err
}
defer func() {
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": req.Username,
"username": req.Username,
}
if err := dbtxn.ExecuteTxQuery(ctx, tx, m, query); err != nil {
return dbplugin.DeleteUserResponse{}, err
}
}
}
return dbplugin.DeleteUserResponse{}, tx.Commit()
}
func (r *RedShift) defaultDeleteUser(ctx context.Context, req dbplugin.DeleteUserRequest) (dbplugin.DeleteUserResponse, error) {
db, err := r.getConnection(ctx)
if err != nil {
return dbplugin.DeleteUserResponse{}, err
}
defer db.Close()
username := req.Username
// Check if the role exists
var exists bool
err = db.QueryRowContext(ctx, "SELECT exists (SELECT usename FROM pg_user WHERE usename=$1);", username).Scan(&exists)
if err != nil && err != sql.ErrNoRows {
return dbplugin.DeleteUserResponse{}, err
}
if !exists {
// No error as Redshift may have deleted the user via TTL before we got to it.
return dbplugin.DeleteUserResponse{}, nil
}
// Query for permissions; we need to revoke permissions before we can drop
// 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, "SELECT DISTINCT table_schema FROM information_schema.role_column_grants WHERE grantee=$1;")
if err != nil {
return dbplugin.DeleteUserResponse{}, err
}
defer stmt.Close()
rows, err := stmt.QueryContext(ctx, username)
if err != nil {
return dbplugin.DeleteUserResponse{}, err
}
defer rows.Close()
const initialNumRevocations = 16
revocationStmts := make([]string, 0, initialNumRevocations)
for rows.Next() {
var schema string
err = rows.Scan(&schema)
if err != nil {
// keep going; remove as many permissions as possible right now
continue
}
revocationStmts = append(revocationStmts, fmt.Sprintf(
`REVOKE ALL PRIVILEGES ON ALL TABLES IN SCHEMA %s FROM %s;`,
pq.QuoteIdentifier(schema),
pq.QuoteIdentifier(username)))
revocationStmts = append(revocationStmts, fmt.Sprintf(
`REVOKE USAGE ON SCHEMA %s FROM %s;`,
pq.QuoteIdentifier(schema),
pq.QuoteIdentifier(username)))
}
// for good measure, revoke all privileges and usage on schema public
revocationStmts = append(revocationStmts, fmt.Sprintf(
`REVOKE ALL PRIVILEGES ON ALL TABLES IN SCHEMA public FROM %s;`,
pq.QuoteIdentifier(username)))
revocationStmts = append(revocationStmts, fmt.Sprintf(
"REVOKE USAGE ON SCHEMA public FROM %s;",
pq.QuoteIdentifier(username)))
// get the current database name so we can issue a REVOKE CONNECT for
// this username
var dbname sql.NullString
if err := db.QueryRowContext(ctx, "SELECT current_database();").Scan(&dbname); err != nil {
return dbplugin.DeleteUserResponse{}, err
}
if dbname.Valid {
/*
We create this stored procedure to ensure we can durably revoke users on Redshift. We do not
clean up since that can cause race conditions with other instances of Vault attempting to use
this SP at the same time.
*/
revocationStmts = append(revocationStmts, `CREATE OR REPLACE PROCEDURE terminateloop(dbusername varchar(100))
LANGUAGE plpgsql
AS $$
DECLARE
currentpid int;
loopvar int;
qtyconns int;
BEGIN
SELECT COUNT(process) INTO qtyconns FROM stv_sessions WHERE user_name=dbusername;
FOR loopvar IN 1..qtyconns LOOP
SELECT INTO currentpid process FROM stv_sessions WHERE user_name=dbusername ORDER BY process ASC LIMIT 1;
SELECT pg_terminate_backend(currentpid);
END LOOP;
END
$$;`)
revocationStmts = append(revocationStmts, fmt.Sprintf(`call terminateloop('%s');`, username))
}
// again, here, we do not stop on error, as we want to remove as
// many permissions as possible right now
var lastStmtError *multierror.Error // error
for _, query := range revocationStmts {
if err := dbtxn.ExecuteDBQuery(ctx, db, nil, query); err != nil {
lastStmtError = multierror.Append(lastStmtError, err)
}
}
// can't drop if not all privileges are revoked
if rows.Err() != nil {
return dbplugin.DeleteUserResponse{}, fmt.Errorf("could not generate revocation statements for all rows: %w", rows.Err())
}
if lastStmtError != nil {
return dbplugin.DeleteUserResponse{}, fmt.Errorf("could not perform all revocation statements: %w", lastStmtError)
}
// Drop this user
stmt, err = db.PrepareContext(ctx, fmt.Sprintf(
`DROP USER IF EXISTS %s;`, pq.QuoteIdentifier(username)))
if err != nil {
return dbplugin.DeleteUserResponse{}, err
}
defer stmt.Close()
if _, err := stmt.ExecContext(ctx); err != nil {
return dbplugin.DeleteUserResponse{}, err
}
return dbplugin.DeleteUserResponse{}, nil
}