open-vault/builtin/logical/postgresql/secret_creds.go
Jeff Mitchell f7147025dd
Migrate to sdk/internalshared libs in go-secure-stdlib (#12090)
* Swap sdk/helper libs to go-secure-stdlib

* Migrate to go-secure-stdlib reloadutil

* Migrate to go-secure-stdlib kv-builder

* Migrate to go-secure-stdlib gatedwriter
2021-07-15 20:17:31 -04:00

269 lines
7.1 KiB
Go

package postgresql
import (
"context"
"database/sql"
"fmt"
"strings"
"time"
"github.com/hashicorp/go-secure-stdlib/strutil"
"github.com/hashicorp/vault/sdk/framework"
"github.com/hashicorp/vault/sdk/helper/dbtxn"
"github.com/hashicorp/vault/sdk/logical"
"github.com/lib/pq"
)
const SecretCredsType = "creds"
func secretCreds(b *backend) *framework.Secret {
return &framework.Secret{
Type: SecretCredsType,
Fields: map[string]*framework.FieldSchema{
"username": {
Type: framework.TypeString,
Description: "Username",
},
"password": {
Type: framework.TypeString,
Description: "Password",
},
},
Renew: b.secretCredsRenew,
Revoke: b.secretCredsRevoke,
}
}
func (b *backend) secretCredsRenew(ctx context.Context, req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
// Get the username from the internal data
usernameRaw, ok := req.Secret.InternalData["username"]
if !ok {
return nil, fmt.Errorf("secret is missing username internal data")
}
username, ok := usernameRaw.(string)
if !ok {
return nil, fmt.Errorf("usernameRaw is not a string")
}
// Get our connection
db, err := b.DB(ctx, req.Storage)
if err != nil {
return nil, err
}
// Get the lease information
lease, err := b.Lease(ctx, req.Storage)
if err != nil {
return nil, err
}
if lease == nil {
lease = &configLease{}
}
// Make sure we increase the VALID UNTIL endpoint for this user.
ttl, _, err := framework.CalculateTTL(b.System(), req.Secret.Increment, lease.Lease, 0, lease.LeaseMax, 0, req.Secret.IssueTime)
if err != nil {
return nil, err
}
if ttl > 0 {
expireTime := time.Now().Add(ttl)
// Adding a small buffer since the TTL will be calculated again afeter this call
// to ensure the database credential does not expire before the lease
expireTime = expireTime.Add(5 * time.Second)
expiration := expireTime.Format("2006-01-02 15:04:05-0700")
query := fmt.Sprintf(
"ALTER ROLE %s VALID UNTIL '%s';",
pq.QuoteIdentifier(username),
expiration)
stmt, err := db.Prepare(query)
if err != nil {
return nil, err
}
defer stmt.Close()
if _, err := stmt.Exec(); err != nil {
return nil, err
}
}
resp := &logical.Response{Secret: req.Secret}
resp.Secret.TTL = lease.Lease
resp.Secret.MaxTTL = lease.LeaseMax
return resp, nil
}
func (b *backend) secretCredsRevoke(ctx context.Context, req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
// Get the username from the internal data
usernameRaw, ok := req.Secret.InternalData["username"]
if !ok {
return nil, fmt.Errorf("secret is missing username internal data")
}
username, ok := usernameRaw.(string)
if !ok {
return nil, fmt.Errorf("usernameRaw is not a string")
}
var revocationSQL string
var resp *logical.Response
roleNameRaw, ok := req.Secret.InternalData["role"]
if ok {
role, err := b.Role(ctx, req.Storage, roleNameRaw.(string))
if err != nil {
return nil, err
}
if role == nil {
if resp == nil {
resp = &logical.Response{}
}
resp.AddWarning(fmt.Sprintf("Role %q cannot be found. Using default revocation SQL.", roleNameRaw.(string)))
} else {
revocationSQL = role.RevocationSQL
}
}
// Get our connection
db, err := b.DB(ctx, req.Storage)
if err != nil {
return nil, err
}
switch revocationSQL {
// This is the default revocation logic. If revocation SQL is provided it
// is simply executed as-is.
case "":
// Check if the role exists
var exists bool
err = db.QueryRow("SELECT exists (SELECT rolname FROM pg_roles WHERE rolname=$1);", username).Scan(&exists)
if err != nil && err != sql.ErrNoRows {
return nil, err
}
if exists == false {
return resp, 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.Prepare("SELECT DISTINCT table_schema FROM information_schema.role_column_grants WHERE grantee=$1;")
if err != nil {
return nil, err
}
defer stmt.Close()
rows, err := stmt.Query(username)
if err != nil {
return nil, 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 ALL PRIVILEGES ON ALL SEQUENCES 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.QueryRow("SELECT current_database();").Scan(&dbname); err != nil {
return nil, err
}
if dbname.Valid {
revocationStmts = append(revocationStmts, fmt.Sprintf(
`REVOKE CONNECT ON DATABASE %s FROM %s;`,
pq.QuoteIdentifier(dbname.String),
pq.QuoteIdentifier(username)))
}
// again, here, we do not stop on error, as we want to remove as
// many permissions as possible right now
var lastStmtError error
for _, query := range revocationStmts {
if err := dbtxn.ExecuteDBQuery(ctx, db, nil, query); err != nil {
lastStmtError = err
}
}
// can't drop if not all privileges are revoked
if rows.Err() != nil {
return nil, fmt.Errorf("could not generate revocation statements for all rows: %w", rows.Err())
}
if lastStmtError != nil {
return nil, fmt.Errorf("could not perform all revocation statements: %w", lastStmtError)
}
// Drop this user
stmt, err = db.Prepare(fmt.Sprintf(
`DROP ROLE IF EXISTS %s;`, pq.QuoteIdentifier(username)))
if err != nil {
return nil, err
}
defer stmt.Close()
if _, err := stmt.Exec(); err != nil {
return nil, err
}
// We have revocation SQL, execute directly, within a transaction
default:
tx, err := db.Begin()
if err != nil {
return nil, err
}
defer func() {
tx.Rollback()
}()
for _, query := range strutil.ParseArbitraryStringSlice(revocationSQL, ";") {
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 nil, err
}
}
if err := tx.Commit(); err != nil {
return nil, err
}
}
return resp, nil
}