highperfocused/lnd
1
0
Fork 0
mirror of https://github.com/lightningnetwork/lnd.git synced 2025-09-07 19:30:46 +02:00
Code Issues Packages Projects Releases Wiki Activity

brontide/conn: migrate to WriteMessage + Flush

Browse Source 
This commit modifies WriteMessage to only perform encryption on the
passed plaintext, and buffer the ciphertext within the connection
object. We then modify internal uses of WriteMessage to follow with a
call to Flush, which actually writes the message to the wire.
Additionally, since WriteMessage does not actually perform the write
itself, the io.Writer argument is removed from the function signature
and all call sites.
This commit is contained in:
Conner Fromknecht
2019-04-22 16:03:56 -07:00
parent ed8fe4bc82
commit 73cf352daa
3 changed files with 43 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

40
brontide/noise.go
View File

@@ -48,6 +48,10 @@ var (
ErrMaxMessageLengthExceeded = errors.New("the generated payload exceeds " +
"the max allowed message length of (2^16)-1")
// ErrMessageNotFlushed signals that the connection cannot accept a new
// message because the prior message has not been fully flushed.
ErrMessageNotFlushed = errors.New("prior message not flushed")
// lightningPrologue is the noise prologue that is used to initialize
// the brontide noise handshake.
lightningPrologue = []byte("lightning")
@@ -692,11 +696,13 @@ func (b *Machine) split() {
}
}
// WriteMessage writes the next message p to the passed io.Writer. The
// ciphertext of the message is prepended with an encrypt+auth'd length which
// must be used as the AD to the AEAD construction when being decrypted by the
// other side.
func (b *Machine) WriteMessage(w io.Writer, p []byte) error {
// WriteMessage encrypts and buffers the next message p. The ciphertext of the
// message is prepended with an encrypt+auth'd length which must be used as the
// AD to the AEAD construction when being decrypted by the other side.
//
// NOTE: This DOES NOT write the message to the wire, it should be followed by a
// call to Flush to ensure the message is written.
func (b *Machine) WriteMessage(p []byte) error {
// The total length of each message payload including the MAC size
// payload exceed the largest number encodable within a 16-bit unsigned
// integer.
@@ -704,6 +710,13 @@ func (b *Machine) WriteMessage(w io.Writer, p []byte) error {
return ErrMaxMessageLengthExceeded
}
// If a prior message was written but it hasn't been fully flushed,
// return an error as we only support buffering of one message at a
// time.
if len(b.nextHeaderSend) > 0 || len(b.nextBodySend) > 0 {
return ErrMessageNotFlushed
}
// The full length of the packet is only the packet length, and does
// NOT include the MAC.
fullLength := uint16(len(p))
@@ -711,18 +724,13 @@ func (b *Machine) WriteMessage(w io.Writer, p []byte) error {
var pktLen [2]byte
binary.BigEndian.PutUint16(pktLen[:], fullLength)
// First, write out the encrypted+MAC'd length prefix for the packet.
cipherLen := b.sendCipher.Encrypt(nil, nil, pktLen[:])
if _, err := w.Write(cipherLen); err != nil {
return err
}
// First, generate the encrypted+MAC'd length prefix for the packet.
b.nextHeaderSend = b.sendCipher.Encrypt(nil, nil, pktLen[:])
// Finally, write out the encrypted packet itself. We only write out a
// single packet, as any fragmentation should have taken place at a
// higher level.
cipherText := b.sendCipher.Encrypt(nil, nil, p)
_, err := w.Write(cipherText)
return err
// Finally, generate the encrypted packet itself.
b.nextBodySend = b.sendCipher.Encrypt(nil, nil, p)
return nil
}
// Flush attempts to write a message buffered using WriteMessage to the provided