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package encoder
import (
"bytes"
"crypto/rand"
"encoding/base64"
"encoding/binary"
"encoding/hex"
"os"
"strings"
"testing"
"golang.org/x/crypto/nacl/box"
)
func testKeyring(t *testing.T) string {
t.Helper()
path := t.TempDir() + "/pubring.mix"
var content strings.Builder
for i, name := range []string{"entry", "middle", "exit"} {
keyID := strings.Repeat(string(rune('a'+i)), 32)
publicKey := strings.Repeat(string(rune('d'+i)), 64)
content.WriteString(name + " " + name + "@example.org " + keyID + " 4:0.2c E 2025-01-01 2099-12-31\n\n")
content.WriteString("-----Begin Mix Key-----\n" + keyID + "\n" + publicKey + "\n-----End Mix Key-----\n")
}
if err := os.WriteFile(path, []byte(content.String()), 0600); err != nil {
t.Fatal(err)
}
return path
}
func TestValidateEmail(t *testing.T) {
r := Request{Kind: Email, PublicKeyring: "/tmp/pubring.mix", Entry: "entry", Chain: []string{"entry"}, To: "user@example.org", Body: "hello"}
if err := Validate(r); err != nil {
t.Fatal(err)
}
}
func TestValidateRejectsPlainIncompleteRequest(t *testing.T) {
r := Request{Kind: Email, PublicKeyring: "/tmp/pubring.mix", Entry: "entry", Chain: []string{"entry"}, To: "bad", Body: "hello"}
if err := Validate(r); err == nil {
t.Fatal("expected invalid recipient")
}
}
func TestValidateUsenetRequiresGatewayRecipient(t *testing.T) {
r := Request{Kind: Usenet, PublicKeyring: "/tmp/pubring.mix", Chain: []string{"entry"}, Newsgroup: "misc.test", Body: "hello"}
if err := Validate(r); err == nil {
t.Fatal("expected missing Usenet gateway recipient to be rejected")
}
r.To = "mail2news@example.org"
if err := Validate(r); err != nil {
t.Fatalf("expected valid Usenet request: %v", err)
}
}
func TestComposeUsenetGatewayHeaders(t *testing.T) {
plain, err := composeMessage(Request{
Kind: Usenet, To: "mail2news@example.org", Subject: "test", Newsgroup: "misc.test", Body: "hello",
References: "<parent@example.org>",
})
if err != nil {
t.Fatal(err)
}
text := string(plain)
if !strings.Contains(text, "To: mail2news@example.org\n") ||
!strings.Contains(text, "Newsgroups: misc.test\n") ||
!strings.Contains(text, "References: <parent@example.org>\n") ||
!strings.Contains(text, "In-Reply-To: <parent@example.org>\n") {
t.Fatalf("missing Usenet delivery headers: %q", text)
}
}
func TestComposeReferencesChainUsesLastIDAsParent(t *testing.T) {
plain, err := composeMessage(Request{
Kind: Usenet, To: "mail2news@example.org", Subject: "test", Newsgroup: "misc.test", Body: "hello",
References: " <root@example.org> <parent@example.org> ",
})
if err != nil {
t.Fatal(err)
}
text := string(plain)
if !strings.Contains(text, "References: <root@example.org> <parent@example.org>\n") ||
!strings.Contains(text, "In-Reply-To: <parent@example.org>\n") {
t.Fatalf("thread headers were not normalized: %q", text)
}
}
func TestValidateReferences(t *testing.T) {
tests := []struct {
name string
references string
valid bool
}{
{name: "empty", valid: true},
{name: "whitespace only", references: " "},
{name: "parent", references: "<parent@example.org>", valid: true},
{name: "thread chain", references: "<root@example.org> <parent@example.org>", valid: true},
{name: "missing brackets", references: "parent@example.org"},
{name: "missing local part", references: "<@example.org>"},
{name: "multiple at signs", references: "<parent@example@org>"},
{name: "embedded newline", references: "<root@example.org>\n<parent@example.org>"},
{name: "header label", references: "References: <parent@example.org>"},
{name: "too long", references: "<" + strings.Repeat("a", maxReferencesBytes) + "@example.org>"},
}
for _, test := range tests {
t.Run(test.name, func(t *testing.T) {
request := Request{
Kind: Email, PublicKeyring: "/tmp/pubring.mix", Entry: "entry", Chain: []string{"entry"},
To: "user@example.org", Body: "hello", References: test.references,
}
err := Validate(request)
if test.valid && err != nil {
t.Fatalf("expected valid References, got %v", err)
}
if !test.valid && err == nil {
t.Fatal("expected invalid References to be rejected")
}
})
}
}
func TestValidateReplyTo(t *testing.T) {
request := Request{
Kind: Email, PublicKeyring: "/tmp/pubring.mix", Entry: "entry", Chain: []string{"entry"},
To: "user@example.org", Body: "hello", ReplyTo: "Pseudonym <reply@example.org>",
}
if err := Validate(request); err != nil {
t.Fatalf("expected valid Reply-To, got %v", err)
}
request.ReplyTo = "not an address"
if err := Validate(request); err == nil {
t.Fatal("expected invalid Reply-To to be rejected")
}
}
func TestEncodeProducesYAMNArmor(t *testing.T) {
keyring := testKeyring(t)
result, err := Encode(Request{
Kind: Email, PublicKeyring: keyring, Entry: "entry", Chain: []string{"entry"},
From: "Anonymous <anon@example.org>", To: "user@example.org", Subject: "test", Body: "hello",
})
if err != nil {
t.Fatal(err)
}
if result.EntryAddress != "entry@example.org" {
t.Fatalf("unexpected entry address: %q", result.EntryAddress)
}
text := string(result.Envelope)
if !strings.Contains(text, "-----BEGIN REMAILER MESSAGE-----") || !strings.Contains(text, "-----END REMAILER MESSAGE-----") {
t.Fatal("missing YAMN armor markers")
}
lines := strings.Split(text, "\n")
start := 0
for i, line := range lines {
if line == "-----BEGIN REMAILER MESSAGE-----" {
start = i + 3
break
}
}
var encoded strings.Builder
for _, line := range lines[start:] {
if line == "" || strings.HasPrefix(line, "-----END") {
break
}
encoded.WriteString(line)
}
packet, err := base64.StdEncoding.DecodeString(encoded.String())
if err != nil {
t.Fatal(err)
}
if len(packet) != messageBytes {
t.Fatalf("unexpected packet size: got %d, want %d", len(packet), messageBytes)
}
}
func TestEncodeMultiHop(t *testing.T) {
result, err := Encode(Request{
Kind: Email, PublicKeyring: testKeyring(t), Entry: "entry",
Chain: []string{"entry", "middle", "exit"}, To: "user@example.org", Body: "hello",
})
if err != nil {
t.Fatal(err)
}
if len(result.Envelope) == 0 || result.EntryAddress != "entry@example.org" {
t.Fatal("multi-hop envelope was not produced")
}
}
func TestEncodeMultiHopDecodesAtEveryRemailer(t *testing.T) {
keyring, secretKeys := testDecodeKeyring(t)
request := Request{
Kind: Email, PublicKeyring: keyring, Entry: "entry",
Chain: []string{"entry", "middle", "exit"}, From: "Anonymous <anon@example.org>",
To: "user@example.org", Subject: "three-hop compatibility", Body: "hello through three remailers",
}
result, err := Encode(request)
if err != nil {
t.Fatal(err)
}
packet := decodeArmoredPacket(t, result.Envelope)
wantPlain, err := composeMessage(request)
if err != nil {
t.Fatal(err)
}
for hop, name := range request.Chain {
data := openHeaderForTest(t, packet[:headerBytes], secretKeys[name])
if data[0] != 2 {
t.Fatalf("hop %d (%s): unexpected packet version %d", hop, name, data[0])
}
if !bytes.Equal(data[117:149], antiTag(packet)) {
t.Fatalf("hop %d (%s): anti-tag mismatch", hop, name)
}
switch data[1] {
case 0:
if hop == len(request.Chain)-1 {
t.Fatalf("hop %d (%s): exit encoded as intermediate", hop, name)
}
shiftHeadersUpForTest(packet)
encryptAll(packet, data[19:51], data[53:65])
case 1:
if hop != len(request.Chain)-1 {
t.Fatalf("hop %d (%s): intermediate encoded as exit", hop, name)
}
bodyLength := int(binary.LittleEndian.Uint32(data[87:91]))
if bodyLength != len(wantPlain) {
t.Fatalf("exit body length: got %d, want %d", bodyLength, len(wantPlain))
}
body := aesCTR(packet[maxChainLength*headerBytes:], data[19:51], data[53:69])
if !bytes.Equal(body[:bodyLength], wantPlain) {
t.Fatal("exit plaintext does not match the encoded message")
}
default:
t.Fatalf("hop %d (%s): unknown packet type %d", hop, name, data[1])
}
}
}
func testDecodeKeyring(t *testing.T) (string, map[string]*[32]byte) {
t.Helper()
path := t.TempDir() + "/pubring.mix"
secretKeys := make(map[string]*[32]byte)
var content strings.Builder
for i, name := range []string{"entry", "middle", "exit"} {
publicKey, secretKey, err := box.GenerateKey(rand.Reader)
if err != nil {
t.Fatal(err)
}
keyID := bytes.Repeat([]byte{byte(i + 1)}, 16)
content.WriteString(name + " " + name + "@example.org " + hex.EncodeToString(keyID) + " 4:0.2c E 2025-01-01 2099-12-31\n\n")
content.WriteString("-----Begin Mix Key-----\n" + hex.EncodeToString(keyID) + "\n" + hex.EncodeToString(publicKey[:]) + "\n-----End Mix Key-----\n")
secretKeys[name] = secretKey
}
if err := os.WriteFile(path, []byte(content.String()), 0600); err != nil {
t.Fatal(err)
}
return path, secretKeys
}
func decodeArmoredPacket(t *testing.T, envelope []byte) []byte {
t.Helper()
lines := strings.Split(string(envelope), "\n")
start := -1
for i, line := range lines {
if line == "-----BEGIN REMAILER MESSAGE-----" {
start = i + 3
break
}
}
if start < 0 {
t.Fatal("missing armored packet start")
}
var encoded strings.Builder
for _, line := range lines[start:] {
if line == "" || strings.HasPrefix(line, "-----END") {
break
}
encoded.WriteString(line)
}
packet, err := base64.StdEncoding.DecodeString(encoded.String())
if err != nil {
t.Fatal(err)
}
if len(packet) != messageBytes {
t.Fatalf("unexpected packet size: got %d, want %d", len(packet), messageBytes)
}
return packet
}
func openHeaderForTest(t *testing.T, header []byte, recipientSecret *[32]byte) []byte {
t.Helper()
var senderPublic [32]byte
copy(senderPublic[:], header[16:48])
var nonce [24]byte
copy(nonce[:], header[48:72])
data, ok := box.Open(nil, header[72:248], &nonce, &senderPublic, recipientSecret)
if !ok {
t.Fatal("header authentication failed")
}
if len(data) != encHeadBytes {
t.Fatalf("unexpected decoded header size: got %d, want %d", len(data), encHeadBytes)
}
return data
}
func shiftHeadersUpForTest(packet []byte) {
headersEnd := maxChainLength * headerBytes
copy(packet, packet[headerBytes:headersEnd])
clear(packet[headersEnd-headerBytes : headersEnd])
}
|
