feat: ✨ add OutlineDevice API that uses Outline SDK

go.mod

@@ -0,0 +1,23 @@
+module github.com/Jigsaw-Code/outline-apps
+
+go 1.20
+
+require (
+	github.com/Jigsaw-Code/outline-sdk v0.0.2
+	github.com/Jigsaw-Code/outline-sdk/x v0.0.0-20230807220427-893de7fdc6b8
+	github.com/stretchr/testify v1.8.4
+	golang.org/x/sys v0.11.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/eycorsican/go-tun2socks v1.16.11 // indirect
+	github.com/miekg/dns v1.1.54 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/shadowsocks/go-shadowsocks2 v0.1.5 // indirect
+	golang.org/x/crypto v0.9.0 // indirect
+	golang.org/x/mod v0.10.0 // indirect
+	golang.org/x/net v0.10.0 // indirect
+	golang.org/x/tools v0.9.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,45 @@
+github.com/Jigsaw-Code/outline-sdk v0.0.2 h1:uCuyJMaWj57IYEG/Hdml8YMdk9chU60ZkSxJXBhyGHU=
+github.com/Jigsaw-Code/outline-sdk v0.0.2/go.mod h1:hhlKz0+r9wSDFT8usvN8Zv/BFToCIFAUn1P2Qk8G2CM=
+github.com/Jigsaw-Code/outline-sdk/x v0.0.0-20230807220427-893de7fdc6b8 h1:BxOHmmuppPM8K0DGUsfvajKF4PKfGxv9boNDhmbszFU=
+github.com/Jigsaw-Code/outline-sdk/x v0.0.0-20230807220427-893de7fdc6b8/go.mod h1:tBqJXpVm+kym+EAUdwNodcFxy872FfjVErfj8Br+gs0=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/eycorsican/go-tun2socks v1.16.11 h1:+hJDNgisrYaGEqoSxhdikMgMJ4Ilfwm/IZDrWRrbaH8=
+github.com/eycorsican/go-tun2socks v1.16.11/go.mod h1:wgB2BFT8ZaPKyKOQ/5dljMG/YIow+AIXyq4KBwJ5sGQ=
+github.com/google/gopacket v1.1.19 h1:ves8RnFZPGiFnTS0uPQStjwru6uO6h+nlr9j6fL7kF8=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/miekg/dns v1.1.54 h1:5jon9mWcb0sFJGpnI99tOMhCPyJ+RPVz5b63MQG0VWI=
+github.com/miekg/dns v1.1.54/go.mod h1:uInx36IzPl7FYnDcMeVWxj9byh7DutNykX4G9Sj60FY=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/riobard/go-bloom v0.0.0-20200614022211-cdc8013cb5b3 h1:f/FNXud6gA3MNr8meMVVGxhp+QBTqY91tM8HjEuMjGg=
+github.com/riobard/go-bloom v0.0.0-20200614022211-cdc8013cb5b3/go.mod h1:HgjTstvQsPGkxUsCd2KWxErBblirPizecHcpD3ffK+s=
+github.com/shadowsocks/go-shadowsocks2 v0.1.5 h1:PDSQv9y2S85Fl7VBeOMF9StzeXZyK1HakRm86CUbr28=
+github.com/shadowsocks/go-shadowsocks2 v0.1.5/go.mod h1:AGGpIoek4HRno4xzyFiAtLHkOpcoznZEkAccaI/rplM=
+github.com/songgao/water v0.0.0-20190725173103-fd331bda3f4b/go.mod h1:P5HUIBuIWKbyjl083/loAegFkfbFNx5i2qEP4CNbm7E=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20210220033148-5ea612d1eb83/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
+golang.org/x/crypto v0.9.0 h1:LF6fAI+IutBocDJ2OT0Q1g8plpYljMZ4+lty+dsqw3g=
+golang.org/x/crypto v0.9.0/go.mod h1:yrmDGqONDYtNj3tH8X9dzUun2m2lzPa9ngI6/RUPGR0=
+golang.org/x/mod v0.10.0 h1:lFO9qtOdlre5W1jxS3r/4szv2/6iXxScdzjoBMXNhYk=
+golang.org/x/mod v0.10.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20191021144547-ec77196f6094/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.10.0 h1:X2//UzNDwYmtCLn7To6G58Wr6f5ahEAQgKNzv9Y951M=
+golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
+golang.org/x/sync v0.2.0 h1:PUR+T4wwASmuSTYdKjYHI5TD22Wy5ogLU5qZCOLxBrI=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
+golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/tools v0.9.1 h1:8WMNJAz3zrtPmnYC7ISf5dEn3MT0gY7jBJfw27yrrLo=
+golang.org/x/tools v0.9.1/go.mod h1:owI94Op576fPu3cIGQeHs3joujW/2Oc6MtlxbF5dfNc=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

outline/config/config.go

@@ -0,0 +1,98 @@
+// Copyright 2023 The Outline Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/Jigsaw-Code/outline-sdk/transport/shadowsocks"
+)
+
+// An internal configuration data structure to be used by Outline transports.
+type TransportConfig struct {
+	Hostname  string
+	Port      int
+	CryptoKey *shadowsocks.EncryptionKey
+	Prefix    []byte
+}
+
+// The configuration interface between the Outline backend and Outline apps.
+// Must match the ShadowsocksSessionConfig interface defined in Outline Client.
+type configJSON struct {
+	Host     string `json:"host"`
+	Port     uint16 `json:"port"`
+	Password string `json:"password"`
+	Method   string `json:"method"`
+	Prefix   string `json:"prefix"`
+}
+
+// ParseConfigFromJSON parses a transport configuration string in JSON format, and returns a corresponding
+// TransportConfig. The JSON string `in` must match the ShadowsocksSessionConfig interface defined in Outline Client.
+func ParseConfigFromJSON(in string) (config *TransportConfig, err error) {
+	var confJson configJSON
+	if err = json.Unmarshal([]byte(in), &confJson); err != nil {
+		return nil, err
+	}
+	if err = validateConfig(&confJson); err != nil {
+		return nil, fmt.Errorf("invalid configuration: %w", err)
+	}
+
+	config = &TransportConfig{
+		Hostname: confJson.Host,
+		Port:     int(confJson.Port),
+	}
+	if config.CryptoKey, err = shadowsocks.NewEncryptionKey(confJson.Method, confJson.Password); err != nil {
+		return nil, fmt.Errorf("invalid cipher: %w", err)
+	}
+	if len(confJson.Prefix) > 0 {
+		if config.Prefix, err = parseStringPrefix(confJson.Prefix); err != nil {
+			return nil, fmt.Errorf("invalid configuration prefix: %w", err)
+		}
+	}
+
+	return config, nil
+}
+
+// validateConfig validates whether an Outline transport configuration is valid (it won't do any connectivity tests).
+//
+// Returns nil if it is valid; or an error if not.
+func validateConfig(config *configJSON) error {
+	if len(config.Host) == 0 {
+		return fmt.Errorf("must provide a hostname or IP address")
+	}
+	if config.Port <= 0 || config.Port > 65535 {
+		return fmt.Errorf("port must be within range [1..65535]")
+	}
+	if len(config.Method) == 0 {
+		return fmt.Errorf("must provide an encryption cipher method")
+	}
+	if len(config.Password) == 0 {
+		return fmt.Errorf("must provide an encryption cipher password")
+	}
+	return nil
+}
+
+func parseStringPrefix(utf8Str string) ([]byte, error) {
+	runes := []rune(utf8Str)
+	rawBytes := make([]byte, len(runes))
+	for i, r := range runes {
+		if (r & 0xFF) != r {
+			return nil, fmt.Errorf("character out of range: %d", r)
+		}
+		rawBytes[i] = byte(r)
+	}
+	return rawBytes, nil
+}

outline/config/config_test.go

@@ -0,0 +1,141 @@
+// Copyright 2023 The Outline Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_ParseConfigFromJSON(t *testing.T) {
+	tests := []struct {
+		name         string
+		input        string
+		expectErr    bool
+		expectHost   string
+		expectPort   int
+		expectPrefix []byte
+	}{
+		{
+			name:       "normal config",
+			input:      `{"host":"192.0.2.1","port":12345,"method":"chacha20-ietf-poly1305","password":"abcd1234"}`,
+			expectHost: "192.0.2.1",
+			expectPort: 12345,
+		},
+		{
+			name:         "normal config with prefix",
+			input:        `{"host":"192.0.2.1","port":12345,"method":"aes-128-gcm","password":"abcd1234","prefix":"abc 123"}`,
+			expectHost:   "192.0.2.1",
+			expectPort:   12345,
+			expectPrefix: []byte("abc 123"),
+		},
+		{
+			name:       "normal config with extra fields",
+			input:      `{"extra_field":"ignored","host":"192.0.2.1","port":12345,"method":"aes-192-gcm","password":"abcd1234"}`,
+			expectHost: "192.0.2.1",
+			expectPort: 12345,
+		},
+		{
+			name:         "unprintable prefix",
+			input:        `{"host":"192.0.2.1","port":12345,"method":"AES-256-gcm","password":"abcd1234","prefix":"abc 123","prefix":"\u0000\u0080\u00ff"}`,
+			expectHost:   "192.0.2.1",
+			expectPort:   12345,
+			expectPrefix: []byte{0x00, 0x80, 0xff},
+		},
+		{
+			name:         "multi-byte utf-8 prefix",
+			input:        `{"host":"192.0.2.1","port":12345,"method":"chacha20-ietf-poly1305","password":"abcd1234","prefix":"abc 123","prefix":"` + "\xc2\x80\xc2\x81\xc3\xbd\xc3\xbf" + `"}`,
+			expectHost:   "192.0.2.1",
+			expectPort:   12345,
+			expectPrefix: []byte{0x80, 0x81, 0xfd, 0xff},
+		},
+		{
+			name:      "missing host",
+			input:     `{"port":12345,"method":"AES-128-GCM","password":"abcd1234"}`,
+			expectErr: true,
+		},
+		{
+			name:      "missing port",
+			input:     `{"host":"192.0.2.1","method":"aes-192-gcm","password":"abcd1234"}`,
+			expectErr: true,
+		},
+		{
+			name:       "missing method",
+			input:      `{"host":"192.0.2.1","port":12345,"password":"abcd1234"}`,
+			expectHost: "192.0.2.1",
+			expectErr:  true,
+		},
+		{
+			name:      "missing password",
+			input:     `{"host":"192.0.2.1","port":12345,"method":"chacha20-ietf-poly1305"}`,
+			expectErr: true,
+		},
+		{
+			name:      "empty host",
+			input:     `{"host":"","port":12345,"method":"chacha20-ietf-poly1305","password":"abcd1234"}`,
+			expectErr: true,
+		},
+		{
+			name:      "zero port",
+			input:     `{"host":"192.0.2.1","port":0,"method":"chacha20-ietf-poly1305","password":"abcd1234"}`,
+			expectErr: true,
+		},
+		{
+			name:      "empty method",
+			input:     `{"host":"192.0.2.1","port":12345,"method":"","password":"abcd1234"}`,
+			expectErr: true,
+		},
+		{
+			name:      "empty password",
+			input:     `{"host":"192.0.2.1","port":12345,"method":"chacha20-ietf-poly1305","password":""}`,
+			expectErr: true,
+		},
+		{
+			name:      "empty prefix",
+			input:     `{"host":"192.0.2.1","port":12345,"method":"some-cipher","password":"abcd1234","prefix":""}`,
+			expectErr: true,
+		},
+		{
+			name:      "port -1",
+			input:     `{"host":"192.0.2.1","port":-1,"method":"aes-128-gcm","password":"abcd1234"}`,
+			expectErr: true,
+		},
+		{
+			name:      "port 65536",
+			input:     `{"host":"192.0.2.1","port":65536,"method":"aes-128-gcm","password":"abcd1234"}`,
+			expectErr: true,
+		},
+		{
+			name:      "prefix out-of-range",
+			input:     `{"host":"192.0.2.1","port":8080,"method":"aes-128-gcm","password":"abcd1234","prefix":"\x1234"}`,
+			expectErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := ParseConfigFromJSON(tt.input)
+			if tt.expectErr {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				require.Equal(t, tt.expectHost, got.Hostname)
+				require.Equal(t, tt.expectPort, got.Port)
+				require.NotNil(t, got.CryptoKey)
+				require.Equal(t, tt.expectPrefix, got.Prefix)
+			}
+		})
+	}
+}

outline/device/device.go

@@ -0,0 +1,68 @@
+// Copyright 2023 The Outline Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package device
+
+import (
+	"fmt"
+
+	"github.com/Jigsaw-Code/outline-apps/outline/config"
+	"github.com/Jigsaw-Code/outline-sdk/network"
+	"github.com/Jigsaw-Code/outline-sdk/network/lwip2transport"
+	"github.com/Jigsaw-Code/outline-sdk/transport"
+)
+
+const (
+	connectivityTestDNSResolver  = "1.1.1.1:53"
+	connectivityTestTargetDomain = "www.google.com"
+)
+
+// OutlineDevice delegates the TCP and UDP traffic from local machine to the remote Outline server.
+type OutlineDevice struct {
+	t2s network.IPDevice
+	pp  *outlinePacketProxy
+	sd  transport.StreamDialer
+}
+
+// NewOutlineDevice creates a new [OutlineDevice] that can relay traffic to a remote Outline server.
+func NewOutlineDevice(configJSON string) (d *OutlineDevice, err error) {
+	config, err := config.ParseConfigFromJSON(configJSON)
+	if err != nil {
+		return nil, err
+	}
+
+	d = &OutlineDevice{}
+
+	if d.sd, err = newOutlineStreamDialer(config); err != nil {
+		return nil, fmt.Errorf("failed to create TCP dialer: %w", err)
+	}
+
+	if d.pp, err = newOutlinePacketProxy(config); err != nil {
+		return nil, fmt.Errorf("failed to create UDP proxy: %w", err)
+	}
+
+	if d.t2s, err = lwip2transport.ConfigureDevice(d.sd, d.pp); err != nil {
+		return nil, fmt.Errorf("failed to configure lwIP: %w", err)
+	}
+
+	return
+}
+
+func (d *OutlineDevice) Close() error {
+	return d.t2s.Close()
+}
+
+func (d *OutlineDevice) Refresh() error {
+	return d.pp.testConnectivityAndRefresh(connectivityTestDNSResolver, connectivityTestTargetDomain)
+}