mautrix-go/crypto/olm/session_goolm.go

111 lines
3.2 KiB
Go

//go:build goolm
package olm
import (
"maunium.net/go/mautrix/crypto/goolm/session"
"maunium.net/go/mautrix/id"
)
// Session stores an end to end encrypted messaging session.
type Session struct {
session.OlmSession
}
// SessionFromPickled loads a Session from a pickled base64 string. Decrypts
// the Session using the supplied key. Returns error on failure.
func SessionFromPickled(pickled, key []byte) (*Session, error) {
if len(pickled) == 0 {
return nil, EmptyInput
}
s := NewBlankSession()
return s, s.Unpickle(pickled, key)
}
func NewBlankSession() *Session {
return &Session{}
}
// Clear clears the memory used to back this Session.
func (s *Session) Clear() error {
s.OlmSession = session.OlmSession{}
return nil
}
// Pickle returns a Session as a base64 string. Encrypts the Session using the
// supplied key.
func (s *Session) Pickle(key []byte) []byte {
if len(key) == 0 {
panic(NoKeyProvided)
}
pickled, err := s.OlmSession.Pickle(key)
if err != nil {
panic(err)
}
return pickled
}
func (s *Session) Unpickle(pickled, key []byte) error {
if len(key) == 0 {
return NoKeyProvided
} else if len(pickled) == 0 {
return EmptyInput
}
sOlm, err := session.OlmSessionFromPickled(pickled, key)
if err != nil {
return err
}
s.OlmSession = *sOlm
return nil
}
// MatchesInboundSession checks if the PRE_KEY message is for this in-bound
// Session. This can happen if multiple messages are sent to this Account
// before this Account sends a message in reply. Returns true if the session
// matches. Returns false if the session does not match. Returns error on
// failure.
func (s *Session) MatchesInboundSession(oneTimeKeyMsg string) (bool, error) {
return s.MatchesInboundSessionFrom("", oneTimeKeyMsg)
}
// MatchesInboundSessionFrom checks if the PRE_KEY message is for this in-bound
// Session. This can happen if multiple messages are sent to this Account
// before this Account sends a message in reply. Returns true if the session
// matches. Returns false if the session does not match. Returns error on
// failure.
func (s *Session) MatchesInboundSessionFrom(theirIdentityKey, oneTimeKeyMsg string) (bool, error) {
if theirIdentityKey != "" {
theirKey := id.Curve25519(theirIdentityKey)
return s.OlmSession.MatchesInboundSessionFrom(&theirKey, []byte(oneTimeKeyMsg))
}
return s.OlmSession.MatchesInboundSessionFrom(nil, []byte(oneTimeKeyMsg))
}
// Encrypt encrypts a message using the Session. Returns the encrypted message
// as base64.
func (s *Session) Encrypt(plaintext []byte) (id.OlmMsgType, []byte) {
if len(plaintext) == 0 {
panic(EmptyInput)
}
messageType, message, err := s.OlmSession.Encrypt(plaintext, nil)
if err != nil {
panic(err)
}
return messageType, message
}
// Decrypt decrypts a message using the Session. Returns the the plain-text on
// success. Returns error on failure.
func (s *Session) Decrypt(message string, msgType id.OlmMsgType) ([]byte, error) {
if len(message) == 0 {
return nil, EmptyInput
}
return s.OlmSession.Decrypt([]byte(message), msgType)
}
// Describe generates a string describing the internal state of an olm session for debugging and logging purposes.
func (s *Session) Describe() string {
return s.OlmSession.Describe()
}