1 files changed, 131 insertions, 0 deletions
diff --git a/vendor/go.mau.fi/whatsmeow/handshake.go b/vendor/go.mau.fi/whatsmeow/handshake.go
new file mode 100644
index 00000000..ecd0398d
--- /dev/null
+++ b/vendor/go.mau.fi/whatsmeow/handshake.go
@@ -0,0 +1,131 @@
+// Copyright (c) 2021 Tulir Asokan
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package whatsmeow
+
+import (
+	"bytes"
+	"fmt"
+	"time"
+
+	"google.golang.org/protobuf/proto"
+
+	waProto "go.mau.fi/whatsmeow/binary/proto"
+	"go.mau.fi/whatsmeow/socket"
+	"go.mau.fi/whatsmeow/util/keys"
+)
+
+const NoiseHandshakeResponseTimeout = 20 * time.Second
+
+// doHandshake implements the Noise_XX_25519_AESGCM_SHA256 handshake for the WhatsApp web API.
+func (cli *Client) doHandshake(fs *socket.FrameSocket, ephemeralKP keys.KeyPair) error {
+	nh := socket.NewNoiseHandshake()
+	nh.Start(socket.NoiseStartPattern, fs.Header)
+	nh.Authenticate(ephemeralKP.Pub[:])
+	data, err := proto.Marshal(&waProto.HandshakeMessage{
+		ClientHello: &waProto.ClientHello{
+			Ephemeral: ephemeralKP.Pub[:],
+		},
+	})
+	if err != nil {
+		return fmt.Errorf("failed to marshal handshake message: %w", err)
+	}
+	err = fs.SendFrame(data)
+	if err != nil {
+		return fmt.Errorf("failed to send handshake message: %w", err)
+	}
+	var resp []byte
+	select {
+	case resp = <-fs.Frames:
+	case <-time.After(NoiseHandshakeResponseTimeout):
+		return fmt.Errorf("timed out waiting for handshake response")
+	}
+	var handshakeResponse waProto.HandshakeMessage
+	err = proto.Unmarshal(resp, &handshakeResponse)
+	if err != nil {
+		return fmt.Errorf("failed to unmarshal handshake response: %w", err)
+	}
+	serverEphemeral := handshakeResponse.GetServerHello().GetEphemeral()
+	serverStaticCiphertext := handshakeResponse.GetServerHello().GetStatic()
+	certificateCiphertext := handshakeResponse.GetServerHello().GetPayload()
+	if len(serverEphemeral) != 32 || serverStaticCiphertext == nil || certificateCiphertext == nil {
+		return fmt.Errorf("missing parts of handshake response")
+	}
+	serverEphemeralArr := *(*[32]byte)(serverEphemeral)
+
+	nh.Authenticate(serverEphemeral)
+	err = nh.MixSharedSecretIntoKey(*ephemeralKP.Priv, serverEphemeralArr)
+	if err != nil {
+		return fmt.Errorf("failed to mix server ephemeral key in: %w", err)
+	}
+
+	staticDecrypted, err := nh.Decrypt(serverStaticCiphertext)
+	if err != nil {
+		return fmt.Errorf("failed to decrypt server static ciphertext: %w", err)
+	} else if len(staticDecrypted) != 32 {
+		return fmt.Errorf("unexpected length of server static plaintext %d (expected 32)", len(staticDecrypted))
+	}
+	err = nh.MixSharedSecretIntoKey(*ephemeralKP.Priv, *(*[32]byte)(staticDecrypted))
+	if err != nil {
+		return fmt.Errorf("failed to mix server static key in: %w", err)
+	}
+
+	certDecrypted, err := nh.Decrypt(certificateCiphertext)
+	if err != nil {
+		return fmt.Errorf("failed to decrypt noise certificate ciphertext: %w", err)
+	}
+	var cert waProto.NoiseCertificate
+	err = proto.Unmarshal(certDecrypted, &cert)
+	if err != nil {
+		return fmt.Errorf("failed to unmarshal noise certificate: %w", err)
+	}
+	certDetailsRaw := cert.GetDetails()
+	certSignature := cert.GetSignature()
+	if certDetailsRaw == nil || certSignature == nil {
+		return fmt.Errorf("missing parts of noise certificate")
+	}
+	var certDetails waProto.NoiseCertificateDetails
+	err = proto.Unmarshal(certDetailsRaw, &certDetails)
+	if err != nil {
+		return fmt.Errorf("failed to unmarshal noise certificate details: %w", err)
+	} else if !bytes.Equal(certDetails.GetKey(), staticDecrypted) {
+		return fmt.Errorf("cert key doesn't match decrypted static")
+	}
+
+	encryptedPubkey := nh.Encrypt(cli.Store.NoiseKey.Pub[:])
+	err = nh.MixSharedSecretIntoKey(*cli.Store.NoiseKey.Priv, serverEphemeralArr)
+	if err != nil {
+		return fmt.Errorf("failed to mix noise private key in: %w", err)
+	}
+
+	clientFinishPayloadBytes, err := proto.Marshal(cli.Store.GetClientPayload())
+	if err != nil {
+		return fmt.Errorf("failed to marshal client finish payload: %w", err)
+	}
+	encryptedClientFinishPayload := nh.Encrypt(clientFinishPayloadBytes)
+	data, err = proto.Marshal(&waProto.HandshakeMessage{
+		ClientFinish: &waProto.ClientFinish{
+			Static:  encryptedPubkey,
+			Payload: encryptedClientFinishPayload,
+		},
+	})
+	if err != nil {
+		return fmt.Errorf("failed to marshal handshake finish message: %w", err)
+	}
+	err = fs.SendFrame(data)
+	if err != nil {
+		return fmt.Errorf("failed to send handshake finish message: %w", err)
+	}
+
+	ns, err := nh.Finish(fs, cli.handleFrame, cli.onDisconnect)
+	if err != nil {
+		return fmt.Errorf("failed to create noise socket: %w", err)
+	}
+
+	cli.socket = ns
+
+	return nil
+}