From c084319478a98631f2a21feb2cc6cfc2ad0785b4 Mon Sep 17 00:00:00 2001
From: jbhusson <jonah@elixxir.io>
Date: Wed, 20 Jul 2022 11:22:51 -0400
Subject: [PATCH] Asymmetric should only encrypt one payload & fill rest with
random bytes
---
broadcast/asymmetric.go | 27 ++++++++-------------------
broadcast/broadcastClient.go | 2 +-
broadcast/processor.go | 19 ++++---------------
3 files changed, 13 insertions(+), 35 deletions(-)
diff --git a/broadcast/asymmetric.go b/broadcast/asymmetric.go
index 9f913b8c2..ed731ff21 100644
--- a/broadcast/asymmetric.go
+++ b/broadcast/asymmetric.go
@@ -11,7 +11,6 @@ import (
"github.com/pkg/errors"
"gitlab.com/elixxir/client/cmix"
"gitlab.com/elixxir/client/cmix/message"
- "gitlab.com/elixxir/primitives/format"
"gitlab.com/xx_network/crypto/multicastRSA"
"gitlab.com/xx_network/primitives/id"
"gitlab.com/xx_network/primitives/id/ephemeral"
@@ -37,26 +36,14 @@ func (bc *broadcastClient) BroadcastAsymmetric(pk multicastRSA.PrivateKey, paylo
return 0, ephemeral.Id{}, errors.New(errNetworkHealth)
}
- if len(payload) != bc.maxAsymmetricPayload() {
+ if len(payload) != bc.MaxAsymmetricPayloadSize() {
return 0, ephemeral.Id{},
errors.Errorf(errPayloadSize, len(payload), bc.maxAsymmetricPayload())
}
- numParts := bc.maxParts()
- size := bc.channel.MaxAsymmetricPayloadSize()
- var mac []byte
- var fp format.Fingerprint
- var sequential []byte
- for i := 0; i < numParts; i++ {
- // Encrypt payload to send using asymmetric channel
- var encryptedPayload []byte
- var err error
- encryptedPayload, mac, fp, err = bc.channel.EncryptAsymmetric(payload[:size], pk, bc.rng.GetStream())
- if err != nil {
- return 0, ephemeral.Id{}, errors.WithMessage(err, "Failed to encrypt asymmetric broadcast message")
- }
- payload = payload[size:]
- sequential = append(sequential, encryptedPayload...)
+ encryptedPayload, mac, fp, err := bc.channel.EncryptAsymmetric(payload, pk, bc.rng.GetStream())
+ if err != nil {
+ return 0, ephemeral.Id{}, errors.WithMessage(err, "Failed to encrypt asymmetric broadcast message")
}
// Create service object to send message
@@ -69,10 +56,12 @@ func (bc *broadcastClient) BroadcastAsymmetric(pk multicastRSA.PrivateKey, paylo
cMixParams.DebugTag = asymmCMixSendTag
}
- sizedPayload, err := NewSizedBroadcast(bc.net.GetMaxMessageLength(), sequential)
+ sizedPayload := make([]byte, bc.net.GetMaxMessageLength())
+ _, err = bc.rng.GetStream().Read(sizedPayload)
if err != nil {
- return id.Round(0), ephemeral.Id{}, err
+ return 0, ephemeral.Id{}, errors.WithMessage(err, "Failed to add random data to sized broadcast")
}
+ copy(sizedPayload[:len(encryptedPayload)], encryptedPayload)
return bc.net.Send(
bc.channel.ReceptionID, fp, service, sizedPayload, mac, cMixParams)
diff --git a/broadcast/broadcastClient.go b/broadcast/broadcastClient.go
index d38975b53..c80f4a50e 100644
--- a/broadcast/broadcastClient.go
+++ b/broadcast/broadcastClient.go
@@ -102,5 +102,5 @@ func (bc *broadcastClient) MaxPayloadSize() int {
}
func (bc *broadcastClient) MaxAsymmetricPayloadSize() int {
- return bc.maxAsymmetricPayload()
+ return bc.channel.MaxAsymmetricPayloadSize()
}
diff --git a/broadcast/processor.go b/broadcast/processor.go
index ec9ab810d..b747eac00 100644
--- a/broadcast/processor.go
+++ b/broadcast/processor.go
@@ -36,24 +36,13 @@ func (p *processor) Process(msg format.Message,
switch p.method {
case Asymmetric:
// We use sized broadcast to fill any remaining bytes in the cmix payload, decode it here
- unsizedPayload, err := DecodeSizedBroadcast(msg.GetContents())
+ encPartSize := p.c.RsaPubKey.Size() // Size of each chunk returned by multicast RSA encryption
+ encodedMessage := msg.GetContents()[:encPartSize]
+ payload, err = p.c.DecryptAsymmetric(encodedMessage)
if err != nil {
- jww.ERROR.Printf("Failed to decode sized broadcast: %+v", err)
+ jww.ERROR.Printf(errDecrypt, p.c.ReceptionID, p.c.Name, err)
return
}
- encPartSize := p.c.RsaPubKey.Size() // Size of each chunk returned by multicast RSA encryption
- numParts := len(unsizedPayload) / encPartSize // Number of chunks in the payload
- // Iterate through & decrypt each chunk, appending to aggregate payload
- for i := 0; i < numParts; i++ {
- var decrypted []byte
- decrypted, err = p.c.DecryptAsymmetric(unsizedPayload[:encPartSize])
- if err != nil {
- jww.ERROR.Printf(errDecrypt, p.c.ReceptionID, p.c.Name, err)
- return
- }
- unsizedPayload = unsizedPayload[encPartSize:]
- payload = append(payload, decrypted...)
- }
case Symmetric:
payload, err = p.c.DecryptSymmetric(msg.GetContents(), msg.GetMac(), msg.GetKeyFP())
--
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