authentication_md5_password.go

package pgproto3

import (
	"encoding/binary"
	"errors"

	"github.com/jackc/pgio"
)

// AuthenticationMD5Password is a message sent from the backend indicating that an MD5 hashed password is required.
type AuthenticationMD5Password struct {
	Salt [4]byte `json:"salt" yaml:"salt,omitempty,flow"`
}

// Backend identifies this message as sendable by the PostgreSQL backend.
func (*AuthenticationMD5Password) Backend() {}

// Backend identifies this message as an authentication response.
func (*AuthenticationMD5Password) 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 *AuthenticationMD5Password) Decode(src []byte) error {
	//println("AuthenticationMD5Password.Decode")
	if len(src) != 8 {
		return errors.New("bad authentication message size")
	}

	authType := binary.BigEndian.Uint32(src)
	//println("authType for MD5 auth ..", authType)
	if authType != AuthTypeMD5Password {
		return errors.New("bad auth type")
	}

	copy(dst.Salt[:], src[4:8])

	return nil
}

// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
func (src *AuthenticationMD5Password) Encode(dst []byte) []byte {
	//println("AuthenticationMD5Password.Encode")
	dst = append(dst, 'R')
	dst = pgio.AppendInt32(dst, 12)
	dst = pgio.AppendUint32(dst, AuthTypeMD5Password)
	dst = append(dst, src.Salt[:]...)
	return dst
}

// // MarshalJSON implements encoding/json.Marshaler.
// func (src AuthenticationMD5Password) MarshalJSON() ([]byte, error) {
// 	return json.Marshal(struct {
// 		Type string
// 		Salt [4]byte
// 	}{
// 		Type: "AuthenticationMD5Password",
// 		Salt: src.Salt,
// 	})
// }

// // UnmarshalJSON implements encoding/json.Unmarshaler.
// func (dst *AuthenticationMD5Password) UnmarshalJSON(data []byte) error {
// 	// Ignore null, like in the main JSON package.
// 	if string(data) == "null" {
// 		return nil
// 	}

// 	var msg struct {
// 		Type string
// 		Salt [4]byte
// 	}
// 	if err := json.Unmarshal(data, &msg); err != nil {
// 		return err
// 	}

// 	dst.Salt = msg.Salt
// 	return nil
// }