package pgproto3 import ( "bytes" "encoding/binary" "encoding/json" "errors" "github.com/jackc/pgx/v5/internal/pgio" ) // AuthenticationSASL is a message sent from the backend indicating that SASL authentication is required. type AuthenticationSASL struct { AuthMechanisms []string } // Backend identifies this message as sendable by the PostgreSQL backend. func (*AuthenticationSASL) Backend() {} // Backend identifies this message as an authentication response. func (*AuthenticationSASL) AuthenticationResponse() {} // Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message // type identifier and 4 byte message length. func (dst *AuthenticationSASL) Decode(src []byte) error { if len(src) < 4 { return errors.New("authentication message too short") } authType := binary.BigEndian.Uint32(src) if authType != AuthTypeSASL { return errors.New("bad auth type") } authMechanisms := src[4:] for len(authMechanisms) > 1 { idx := bytes.IndexByte(authMechanisms, 0) if idx == -1 { return &invalidMessageFormatErr{messageType: "AuthenticationSASL", details: "unterminated string"} } dst.AuthMechanisms = append(dst.AuthMechanisms, string(authMechanisms[:idx])) authMechanisms = authMechanisms[idx+1:] } return nil } // Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length. func (src *AuthenticationSASL) Encode(dst []byte) []byte { dst = append(dst, 'R') sp := len(dst) dst = pgio.AppendInt32(dst, -1) dst = pgio.AppendUint32(dst, AuthTypeSASL) for _, s := range src.AuthMechanisms { dst = append(dst, []byte(s)...) dst = append(dst, 0) } dst = append(dst, 0) pgio.SetInt32(dst[sp:], int32(len(dst[sp:]))) return dst } // MarshalJSON implements encoding/json.Marshaler. func (src AuthenticationSASL) MarshalJSON() ([]byte, error) { return json.Marshal(struct { Type string AuthMechanisms []string }{ Type: "AuthenticationSASL", AuthMechanisms: src.AuthMechanisms, }) }