Merge remote-tracking branch 'pgconn/master' into v5-dev

internal/stmtcache/lru.go

@@ -102,10 +102,14 @@ func (c *LRU) StatementErrored(sql string, err error) {
 		return
 	}
 
-	isInvalidCachedPlanError := pgErr.Severity == "ERROR" &&
-		pgErr.Code == "0A000" &&
-		pgErr.Message == "cached plan must not change result type"
-	if isInvalidCachedPlanError {
+	// https://github.com/jackc/pgx/issues/1162
+	//
+	// We used to look for the message "cached plan must not change result type". However, that message can be localized.
+	// Unfortunately, error code "0A000" - "FEATURE NOT SUPPORTED" is used for many different errors and the only way to
+	// tell the difference is by the message. But all that happens is we clear a statement that we otherwise wouldn't
+	// have so it should be safe.
+	possibleInvalidCachedPlanError := pgErr.Code == "0A000"
+	if possibleInvalidCachedPlanError {
 		c.stmtsToClear = append(c.stmtsToClear, sql)
 	}
 }

pgconn/config.go

@@ -175,8 +175,6 @@ func NetworkAddress(host string, port uint16) (network, address string) {
 //
 // Other known differences with libpq:
 //
-// If a host name resolves into multiple addresses, libpq will try all addresses. pgconn will only try the first.
-//
 // When multiple hosts are specified, libpq allows them to have different passwords set via the .pgpass file. pgconn
 // does not.
 //
@@ -253,6 +251,8 @@ func ParseConfig(connString string) (*Config, error) {
 		"sslkey":               {},
 		"sslcert":              {},
 		"sslrootcert":          {},
+		"krbspn":               {},
+		"krbsrvname":           {},
 		"target_session_attrs": {},
 		"service":              {},
 		"servicefile":          {},

pgconn/krb5.go

@@ -0,0 +1,95 @@
+package pgconn
+
+import (
+	"errors"
+
+	"github.com/jackc/pgx/v5/pgproto3"
+)
+
+// NewGSSFunc creates a GSS authentication provider, for use with
+// RegisterGSSProvider.
+type NewGSSFunc func() (GSS, error)
+
+var newGSS NewGSSFunc
+
+// RegisterGSSProvider registers a GSS authentication provider. For example, if
+// you need to use Kerberos to authenticate with your server, add this to your
+// main package:
+//
+//	import "github.com/otan/gopgkrb5"
+//
+//	func init() {
+//		pgconn.RegisterGSSProvider(func() (pgconn.GSS, error) { return gopgkrb5.NewGSS() })
+//	}
+func RegisterGSSProvider(newGSSArg NewGSSFunc) {
+	newGSS = newGSSArg
+}
+
+// GSS provides GSSAPI authentication (e.g., Kerberos).
+type GSS interface {
+	GetInitToken(host string, service string) ([]byte, error)
+	GetInitTokenFromSPN(spn string) ([]byte, error)
+	Continue(inToken []byte) (done bool, outToken []byte, err error)
+}
+
+func (c *PgConn) gssAuth() error {
+	if newGSS == nil {
+		return errors.New("kerberos error: no GSSAPI provider registered, see https://github.com/otan/gopgkrb5")
+	}
+	cli, err := newGSS()
+	if err != nil {
+		return err
+	}
+
+	var nextData []byte
+	if spn, ok := c.config.RuntimeParams["krbspn"]; ok {
+		// Use the supplied SPN if provided.
+		nextData, err = cli.GetInitTokenFromSPN(spn)
+	} else {
+		// Allow the kerberos service name to be overridden
+		service := "postgres"
+		if val, ok := c.config.RuntimeParams["krbsrvname"]; ok {
+			service = val
+		}
+		nextData, err = cli.GetInitToken(c.config.Host, service)
+	}
+	if err != nil {
+		return err
+	}
+
+	for {
+		gssResponse := &pgproto3.GSSResponse{
+			Data: nextData,
+		}
+		_, err = c.conn.Write(gssResponse.Encode(nil))
+		if err != nil {
+			return err
+		}
+		resp, err := c.rxGSSContinue()
+		if err != nil {
+			return err
+		}
+		var done bool
+		done, nextData, err = cli.Continue(resp.Data)
+		if err != nil {
+			return err
+		}
+		if done {
+			break
+		}
+	}
+	return nil
+}
+
+func (c *PgConn) rxGSSContinue() (*pgproto3.AuthenticationGSSContinue, error) {
+	msg, err := c.receiveMessage()
+	if err != nil {
+		return nil, err
+	}
+	gssContinue, ok := msg.(*pgproto3.AuthenticationGSSContinue)
+	if ok {
+		return gssContinue, nil
+	}
+
+	return nil, errors.New("expected AuthenticationGSSContinue message but received unexpected message")
+}

pgconn/pgconn.go

@@ -99,7 +99,7 @@ type PgConn struct {
 }
 
 // Connect establishes a connection to a PostgreSQL server using the environment and connString (in URL or DSN format)
-// to provide configuration. See documention for ParseConfig for details. ctx can be used to cancel a connect attempt.
+// to provide configuration. See documentation for ParseConfig for details. ctx can be used to cancel a connect attempt.
 func Connect(ctx context.Context, connString string) (*PgConn, error) {
 	config, err := ParseConfig(connString)
 	if err != nil {
@@ -154,9 +154,14 @@ func ConnectConfig(ctx context.Context, config *Config) (pgConn *PgConn, err err
 			break
 		} else if pgerr, ok := err.(*PgError); ok {
 			err = &connectError{config: config, msg: "server error", err: pgerr}
-			ERRCODE_INVALID_PASSWORD := "28P01"                    // worng password
-			ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION := "28000" // db does not exist
-			if pgerr.Code == ERRCODE_INVALID_PASSWORD || pgerr.Code == ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION {
+			const ERRCODE_INVALID_PASSWORD = "28P01"                    // wrong password
+			const ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION = "28000" // wrong password or bad pg_hba.conf settings
+			const ERRCODE_INVALID_CATALOG_NAME = "3D000"                // db does not exist
+			const ERRCODE_INSUFFICIENT_PRIVILEGE = "42501"              // missing connect privilege
+			if pgerr.Code == ERRCODE_INVALID_PASSWORD ||
+				pgerr.Code == ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION ||
+				pgerr.Code == ERRCODE_INVALID_CATALOG_NAME ||
+				pgerr.Code == ERRCODE_INSUFFICIENT_PRIVILEGE {
 				break
 			}
 		}
@@ -317,7 +322,12 @@ func connect(ctx context.Context, config *Config, fallbackConfig *FallbackConfig
 				pgConn.conn.Close()
 				return nil, &connectError{config: config, msg: "failed SASL auth", err: err}
 			}
-
+		case *pgproto3.AuthenticationGSS:
+			err = pgConn.gssAuth()
+			if err != nil {
+				pgConn.conn.Close()
+				return nil, &connectError{config: config, msg: "failed GSS auth", err: err}
+			}
 		case *pgproto3.ReadyForQuery:
 			pgConn.status = connStatusIdle
 			if config.ValidateConnect != nil {