mox/smtpclient/client_test.go
Mechiel Lukkien 9152384fd3
use debug logging in tests
by setting the loglevel to debug in package mlog.
we restore the "info" logging in main.
except for "mox localserve", which still sets debug by default.
2024-05-10 15:51:48 +02:00

941 lines
29 KiB
Go

package smtpclient
import (
"bufio"
"context"
"crypto/ed25519"
cryptorand "crypto/rand"
"crypto/sha1"
"crypto/sha256"
"crypto/tls"
"crypto/x509"
"encoding/base64"
"errors"
"fmt"
"hash"
"io"
"log/slog"
"math/big"
"net"
"reflect"
"strings"
"testing"
"time"
"github.com/mjl-/mox/dns"
"github.com/mjl-/mox/mlog"
"github.com/mjl-/mox/sasl"
"github.com/mjl-/mox/scram"
"github.com/mjl-/mox/smtp"
)
var zerohost dns.Domain
var localhost = dns.Domain{ASCII: "localhost"}
func TestClient(t *testing.T) {
ctx := context.Background()
log := mlog.New("smtpclient", nil)
mlog.SetConfig(map[string]slog.Level{"": mlog.LevelTrace})
defer mlog.SetConfig(map[string]slog.Level{"": mlog.LevelDebug})
type options struct {
// Server behaviour.
pipelining bool
ecodes bool
maxSize int
starttls bool
eightbitmime bool
smtputf8 bool
requiretls bool
ehlo bool
auths []string // Allowed mechanisms.
nodeliver bool // For server, whether client will attempt a delivery.
// Client behaviour.
tlsMode TLSMode
tlsPKIX bool
roots *x509.CertPool
tlsHostname dns.Domain
need8bitmime bool
needsmtputf8 bool
needsrequiretls bool
recipients []string // If nil, mjl@mox.example is used.
resps []Response // Checked only if non-nil.
}
// Make fake cert, and make it trusted.
cert := fakeCert(t, false)
roots := x509.NewCertPool()
roots.AddCert(cert.Leaf)
tlsConfig := tls.Config{
Certificates: []tls.Certificate{cert},
}
cleanupResp := func(resps []Response) []Response {
for i, r := range resps {
resps[i] = Response{Code: r.Code, Secode: r.Secode}
}
return resps
}
test := func(msg string, opts options, auth func(l []string, cs *tls.ConnectionState) (sasl.Client, error), expClientErr, expDeliverErr, expServerErr error) {
t.Helper()
if opts.tlsMode == "" {
opts.tlsMode = TLSOpportunistic
}
clientConn, serverConn := net.Pipe()
defer serverConn.Close()
result := make(chan error, 2)
go func() {
defer func() {
x := recover()
if x != nil && x != "stop" {
panic(x)
}
}()
fail := func(format string, args ...any) {
err := fmt.Errorf("server: %w", fmt.Errorf(format, args...))
log.Errorx("failure", err)
if err != nil && expServerErr != nil && (errors.Is(err, expServerErr) || errors.As(err, reflect.New(reflect.ValueOf(expServerErr).Type()).Interface())) {
err = nil
}
result <- err
panic("stop")
}
br := bufio.NewReader(serverConn)
readline := func(prefix string) string {
s, err := br.ReadString('\n')
if err != nil {
fail("expected command: %v", err)
}
if !strings.HasPrefix(strings.ToLower(s), strings.ToLower(prefix)) {
fail("expected command %q, got: %s", prefix, s)
}
s = s[len(prefix):]
return strings.TrimSuffix(s, "\r\n")
}
writeline := func(s string) {
fmt.Fprintf(serverConn, "%s\r\n", s)
}
haveTLS := false
ehlo := true // Initially we expect EHLO.
var hello func()
hello = func() {
if !ehlo {
readline("HELO")
writeline("250 mox.example")
return
}
readline("EHLO")
if !opts.ehlo {
// Client will try again with HELO.
writeline("500 bad syntax")
ehlo = false
hello()
return
}
writeline("250-mox.example")
if opts.pipelining {
writeline("250-PIPELINING")
}
if opts.maxSize > 0 {
writeline(fmt.Sprintf("250-SIZE %d", opts.maxSize))
}
if opts.ecodes {
writeline("250-ENHANCEDSTATUSCODES")
}
if opts.starttls && !haveTLS {
writeline("250-STARTTLS")
}
if opts.eightbitmime {
writeline("250-8BITMIME")
}
if opts.smtputf8 {
writeline("250-SMTPUTF8")
}
if opts.requiretls && haveTLS {
writeline("250-REQUIRETLS")
}
if opts.auths != nil {
writeline("250-AUTH " + strings.Join(opts.auths, " "))
}
writeline("250-LIMITS MAILMAX=10 RCPTMAX=100 RCPTDOMAINMAX=1")
writeline("250 UNKNOWN") // To be ignored.
}
writeline("220 mox.example ESMTP test")
hello()
if opts.starttls {
readline("STARTTLS")
writeline("220 go")
tlsConn := tls.Server(serverConn, &tlsConfig)
nctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
defer cancel()
err := tlsConn.HandshakeContext(nctx)
if err != nil {
fail("tls handshake: %w", err)
}
serverConn = tlsConn
br = bufio.NewReader(serverConn)
haveTLS = true
hello()
}
if opts.auths != nil {
more := readline("AUTH ")
t := strings.SplitN(more, " ", 2)
switch t[0] {
case "PLAIN":
writeline("235 2.7.0 auth ok")
case "CRAM-MD5":
writeline("334 " + base64.StdEncoding.EncodeToString([]byte("<123.1234@host>")))
readline("") // Proof
writeline("235 2.7.0 auth ok")
case "SCRAM-SHA-256-PLUS", "SCRAM-SHA-256", "SCRAM-SHA-1-PLUS", "SCRAM-SHA-1":
// Cannot fake/hardcode scram interactions.
var h func() hash.Hash
salt := scram.MakeRandom()
var iterations int
switch t[0] {
case "SCRAM-SHA-1-PLUS", "SCRAM-SHA-1":
h = sha1.New
iterations = 2 * 4096
case "SCRAM-SHA-256-PLUS", "SCRAM-SHA-256":
h = sha256.New
iterations = 4096
default:
panic("missing case for scram")
}
var cs *tls.ConnectionState
if strings.HasSuffix(t[0], "-PLUS") {
if !haveTLS {
writeline("501 scram plus without tls not possible")
readline("QUIT")
writeline("221 ok")
result <- nil
return
}
xcs := serverConn.(*tls.Conn).ConnectionState()
cs = &xcs
}
saltedPassword := scram.SaltPassword(h, "test", salt, iterations)
clientFirst, err := base64.StdEncoding.DecodeString(t[1])
if err != nil {
fail("bad base64: %w", err)
}
s, err := scram.NewServer(h, clientFirst, cs, cs != nil)
if err != nil {
fail("scram new server: %w", err)
}
serverFirst, err := s.ServerFirst(iterations, salt)
if err != nil {
fail("scram server first: %w", err)
}
writeline("334 " + base64.StdEncoding.EncodeToString([]byte(serverFirst)))
xclientFinal := readline("")
clientFinal, err := base64.StdEncoding.DecodeString(xclientFinal)
if err != nil {
fail("bad base64: %w", err)
}
serverFinal, err := s.Finish([]byte(clientFinal), saltedPassword)
if err != nil {
fail("scram finish: %w", err)
}
writeline("334 " + base64.StdEncoding.EncodeToString([]byte(serverFinal)))
readline("")
writeline("235 2.7.0 auth ok")
default:
writeline("501 unknown mechanism")
}
}
if expClientErr == nil && !opts.nodeliver {
readline("MAIL FROM:")
writeline("250 ok")
n := len(opts.recipients)
if n == 0 {
n = 1
}
for i := 0; i < n; i++ {
readline("RCPT TO:")
resp := "250 ok"
if i < len(opts.resps) {
resp = fmt.Sprintf("%d maybe", opts.resps[i].Code)
}
writeline(resp)
}
readline("DATA")
writeline("354 continue")
reader := smtp.NewDataReader(br)
io.Copy(io.Discard, reader)
writeline("250 ok")
if expDeliverErr == nil {
readline("RSET")
writeline("250 ok")
readline("MAIL FROM:")
writeline("250 ok")
for i := 0; i < n; i++ {
readline("RCPT TO:")
resp := "250 ok"
if i < len(opts.resps) {
resp = fmt.Sprintf("%d maybe", opts.resps[i].Code)
}
writeline(resp)
}
readline("DATA")
writeline("354 continue")
reader = smtp.NewDataReader(br)
io.Copy(io.Discard, reader)
writeline("250 ok")
}
}
readline("QUIT")
writeline("221 ok")
result <- nil
}()
// todo: should abort tests more properly. on client failures, we may be left with hanging test.
go func() {
defer func() {
x := recover()
if x != nil && x != "stop" {
panic(x)
}
}()
fail := func(format string, args ...any) {
err := fmt.Errorf("client: %w", fmt.Errorf(format, args...))
log.Errorx("failure", err)
result <- err
panic("stop")
}
client, err := New(ctx, log.Logger, clientConn, opts.tlsMode, opts.tlsPKIX, localhost, opts.tlsHostname, Opts{Auth: auth, RootCAs: opts.roots})
if (err == nil) != (expClientErr == nil) || err != nil && !errors.As(err, reflect.New(reflect.ValueOf(expClientErr).Type()).Interface()) && !errors.Is(err, expClientErr) {
fail("new client: got err %v, expected %#v", err, expClientErr)
}
if err != nil {
result <- nil
return
}
rcptTo := opts.recipients
if len(rcptTo) == 0 {
rcptTo = []string{"mjl@mox.example"}
}
resps, err := client.DeliverMultiple(ctx, "postmaster@mox.example", rcptTo, int64(len(msg)), strings.NewReader(msg), opts.need8bitmime, opts.needsmtputf8, opts.needsrequiretls)
if (err == nil) != (expDeliverErr == nil) || err != nil && !errors.Is(err, expDeliverErr) && !reflect.DeepEqual(err, expDeliverErr) {
fail("first deliver: got err %#v (%s), expected %#v (%s)", err, err, expDeliverErr, expDeliverErr)
} else if opts.resps != nil && !reflect.DeepEqual(cleanupResp(resps), opts.resps) {
fail("first deliver: got resps %v, expected %v", resps, opts.resps)
}
if err == nil {
err = client.Reset()
if err != nil {
fail("reset: %v", err)
}
resps, err = client.DeliverMultiple(ctx, "postmaster@mox.example", rcptTo, int64(len(msg)), strings.NewReader(msg), opts.need8bitmime, opts.needsmtputf8, opts.needsrequiretls)
if (err == nil) != (expDeliverErr == nil) || err != nil && !errors.Is(err, expDeliverErr) && !reflect.DeepEqual(err, expDeliverErr) {
fail("second deliver: got err %#v (%s), expected %#v (%s)", err, err, expDeliverErr, expDeliverErr)
} else if opts.resps != nil && !reflect.DeepEqual(cleanupResp(resps), opts.resps) {
fail("second: got resps %v, expected %v", resps, opts.resps)
}
}
err = client.Close()
if err != nil {
fail("close client: %v", err)
}
result <- nil
}()
var errs []error
for i := 0; i < 2; i++ {
err := <-result
if err != nil {
errs = append(errs, err)
}
}
if errs != nil {
t.Fatalf("%v", errs)
}
}
msg := strings.ReplaceAll(`From: <postmaster@mox.example>
To: <mjl@mox.example>
Subject: test
test
`, "\n", "\r\n")
allopts := options{
pipelining: true,
ecodes: true,
maxSize: 512,
eightbitmime: true,
smtputf8: true,
starttls: true,
ehlo: true,
requiretls: true,
tlsMode: TLSRequiredStartTLS,
tlsPKIX: true,
roots: roots,
tlsHostname: dns.Domain{ASCII: "mox.example"},
need8bitmime: true,
needsmtputf8: true,
needsrequiretls: true,
}
test(msg, options{}, nil, nil, nil, nil)
test(msg, allopts, nil, nil, nil, nil)
test(msg, options{ehlo: true, eightbitmime: true}, nil, nil, nil, nil)
test(msg, options{ehlo: true, eightbitmime: false, need8bitmime: true, nodeliver: true}, nil, nil, Err8bitmimeUnsupported, nil)
test(msg, options{ehlo: true, smtputf8: false, needsmtputf8: true, nodeliver: true}, nil, nil, ErrSMTPUTF8Unsupported, nil)
// Server TLS handshake is a net.OpError with "remote error" as text.
test(msg, options{ehlo: true, starttls: true, tlsMode: TLSRequiredStartTLS, tlsPKIX: true, tlsHostname: dns.Domain{ASCII: "mismatch.example"}, nodeliver: true}, nil, ErrTLS, nil, &net.OpError{})
test(msg, options{ehlo: true, maxSize: len(msg) - 1, nodeliver: true}, nil, nil, ErrSize, nil)
// Multiple recipients, not pipelined.
multi1 := options{
ehlo: true,
pipelining: true,
ecodes: true,
recipients: []string{"mjl@mox.example", "mjl2@mox.example", "mjl3@mox.example"},
resps: []Response{
{Code: smtp.C250Completed},
{Code: smtp.C250Completed},
{Code: smtp.C250Completed},
},
}
test(msg, multi1, nil, nil, nil, nil)
multi1.pipelining = true
test(msg, multi1, nil, nil, nil, nil)
// Multiple recipients with 452 and other error, not pipelined
multi2 := options{
ehlo: true,
ecodes: true,
recipients: []string{"xmjl@mox.example", "xmjl2@mox.example", "xmjl3@mox.example"},
resps: []Response{
{Code: smtp.C250Completed},
{Code: smtp.C554TransactionFailed}, // Will continue when not pipelined.
{Code: smtp.C452StorageFull}, // Will stop sending further recipients.
},
}
test(msg, multi2, nil, nil, nil, nil)
multi2.pipelining = true
test(msg, multi2, nil, nil, nil, nil)
multi2.pipelining = false
multi2.resps[2].Code = smtp.C552MailboxFull
test(msg, multi2, nil, nil, nil, nil)
multi2.pipelining = true
test(msg, multi2, nil, nil, nil, nil)
// Single recipient with error and pipelining is an error.
multi3 := options{
ehlo: true,
pipelining: true,
ecodes: true,
recipients: []string{"xmjl@mox.example"},
resps: []Response{{Code: smtp.C452StorageFull}},
}
test(msg, multi3, nil, nil, Error{Code: smtp.C452StorageFull, Command: "rcptto", Line: "452 maybe"}, nil)
authPlain := func(l []string, cs *tls.ConnectionState) (sasl.Client, error) {
return sasl.NewClientPlain("test", "test"), nil
}
test(msg, options{ehlo: true, auths: []string{"PLAIN"}}, authPlain, nil, nil, nil)
authCRAMMD5 := func(l []string, cs *tls.ConnectionState) (sasl.Client, error) {
return sasl.NewClientCRAMMD5("test", "test"), nil
}
test(msg, options{ehlo: true, auths: []string{"CRAM-MD5"}}, authCRAMMD5, nil, nil, nil)
// todo: add tests for failing authentication, also at various stages in SCRAM
authSCRAMSHA1 := func(l []string, cs *tls.ConnectionState) (sasl.Client, error) {
return sasl.NewClientSCRAMSHA1("test", "test", false), nil
}
test(msg, options{ehlo: true, auths: []string{"SCRAM-SHA-1"}}, authSCRAMSHA1, nil, nil, nil)
authSCRAMSHA1PLUS := func(l []string, cs *tls.ConnectionState) (sasl.Client, error) {
return sasl.NewClientSCRAMSHA1PLUS("test", "test", *cs), nil
}
test(msg, options{ehlo: true, starttls: true, auths: []string{"SCRAM-SHA-1-PLUS"}}, authSCRAMSHA1PLUS, nil, nil, nil)
authSCRAMSHA256 := func(l []string, cs *tls.ConnectionState) (sasl.Client, error) {
return sasl.NewClientSCRAMSHA256("test", "test", false), nil
}
test(msg, options{ehlo: true, auths: []string{"SCRAM-SHA-256"}}, authSCRAMSHA256, nil, nil, nil)
authSCRAMSHA256PLUS := func(l []string, cs *tls.ConnectionState) (sasl.Client, error) {
return sasl.NewClientSCRAMSHA256PLUS("test", "test", *cs), nil
}
test(msg, options{ehlo: true, starttls: true, auths: []string{"SCRAM-SHA-256-PLUS"}}, authSCRAMSHA256PLUS, nil, nil, nil)
test(msg, options{ehlo: true, requiretls: false, needsrequiretls: true, nodeliver: true}, nil, nil, ErrRequireTLSUnsupported, nil)
// Set an expired certificate. For non-strict TLS, we should still accept it.
// ../rfc/7435:424
cert = fakeCert(t, true)
roots = x509.NewCertPool()
roots.AddCert(cert.Leaf)
tlsConfig = tls.Config{
Certificates: []tls.Certificate{cert},
}
test(msg, options{ehlo: true, starttls: true, roots: roots}, nil, nil, nil, nil)
// Again with empty cert pool so it isn't trusted in any way.
roots = x509.NewCertPool()
tlsConfig = tls.Config{
Certificates: []tls.Certificate{cert},
}
test(msg, options{ehlo: true, starttls: true, roots: roots}, nil, nil, nil, nil)
}
func TestErrors(t *testing.T) {
ctx := context.Background()
log := mlog.New("smtpclient", nil)
// Invalid greeting.
run(t, func(s xserver) {
s.writeline("bogus") // Invalid, should be "220 <hostname>".
}, func(conn net.Conn) {
_, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
var xerr Error
if err == nil || !errors.Is(err, ErrProtocol) || !errors.As(err, &xerr) || xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrProtocol without Permanent", err))
}
})
// Server just closes connection.
run(t, func(s xserver) {
s.conn.Close()
}, func(conn net.Conn) {
_, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
var xerr Error
if err == nil || !errors.Is(err, io.ErrUnexpectedEOF) || !errors.As(err, &xerr) || xerr.Permanent {
panic(fmt.Errorf("got %#v (%v), expected ErrUnexpectedEOF without Permanent", err, err))
}
})
// Server does not want to speak SMTP.
run(t, func(s xserver) {
s.writeline("521 not accepting connections")
}, func(conn net.Conn) {
_, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
var xerr Error
if err == nil || !errors.Is(err, ErrStatus) || !errors.As(err, &xerr) || !xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrStatus with Permanent", err))
}
})
// Server has invalid code in greeting.
run(t, func(s xserver) {
s.writeline("2200 mox.example") // Invalid, too many digits.
}, func(conn net.Conn) {
_, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
var xerr Error
if err == nil || !errors.Is(err, ErrProtocol) || !errors.As(err, &xerr) || xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrProtocol without Permanent", err))
}
})
// Server sends multiline response, but with different codes.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250-mox.example")
s.writeline("500 different code") // Invalid.
}, func(conn net.Conn) {
_, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
var xerr Error
if err == nil || !errors.Is(err, ErrProtocol) || !errors.As(err, &xerr) || xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrProtocol without Permanent", err))
}
})
// Server permanently refuses MAIL FROM.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250-mox.example")
s.writeline("250 ENHANCEDSTATUSCODES")
s.readline("MAIL FROM:")
s.writeline("550 5.7.0 not allowed")
}, func(conn net.Conn) {
c, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
if err != nil {
panic(err)
}
msg := ""
err = c.Deliver(ctx, "postmaster@other.example", "mjl@mox.example", int64(len(msg)), strings.NewReader(msg), false, false, false)
var xerr Error
if err == nil || !errors.Is(err, ErrStatus) || !errors.As(err, &xerr) || !xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrStatus with Permanent", err))
}
})
// Server temporarily refuses MAIL FROM.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250 mox.example")
s.readline("MAIL FROM:")
s.writeline("451 bad sender")
}, func(conn net.Conn) {
c, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
if err != nil {
panic(err)
}
msg := ""
err = c.Deliver(ctx, "postmaster@other.example", "mjl@mox.example", int64(len(msg)), strings.NewReader(msg), false, false, false)
var xerr Error
if err == nil || !errors.Is(err, ErrStatus) || !errors.As(err, &xerr) || xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrStatus with not-Permanent", err))
}
})
// Server temporarily refuses RCPT TO.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250 mox.example")
s.readline("MAIL FROM:")
s.writeline("250 ok")
s.readline("RCPT TO:")
s.writeline("451")
}, func(conn net.Conn) {
c, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
if err != nil {
panic(err)
}
msg := ""
err = c.Deliver(ctx, "postmaster@other.example", "mjl@mox.example", int64(len(msg)), strings.NewReader(msg), false, false, false)
var xerr Error
if err == nil || !errors.Is(err, ErrStatus) || !errors.As(err, &xerr) || xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrStatus with not-Permanent", err))
}
})
// Server permanently refuses DATA.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250 mox.example")
s.readline("MAIL FROM:")
s.writeline("250 ok")
s.readline("RCPT TO:")
s.writeline("250 ok")
s.readline("DATA")
s.writeline("550 no!")
}, func(conn net.Conn) {
c, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
if err != nil {
panic(err)
}
msg := ""
err = c.Deliver(ctx, "postmaster@other.example", "mjl@mox.example", int64(len(msg)), strings.NewReader(msg), false, false, false)
var xerr Error
if err == nil || !errors.Is(err, ErrStatus) || !errors.As(err, &xerr) || !xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrStatus with Permanent", err))
}
})
// TLS is required, so we attempt it regardless of whether it is advertised.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250 mox.example")
s.readline("STARTTLS")
s.writeline("502 command not implemented")
}, func(conn net.Conn) {
_, err := New(ctx, log.Logger, conn, TLSRequiredStartTLS, true, localhost, dns.Domain{ASCII: "mox.example"}, Opts{})
var xerr Error
if err == nil || !errors.Is(err, ErrTLS) || !errors.As(err, &xerr) || !xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrTLS with Permanent", err))
}
})
// If TLS is available, but we don't want to use it, client should skip it.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250-mox.example")
s.writeline("250 STARTTLS")
s.readline("MAIL FROM:")
s.writeline("451 enough")
}, func(conn net.Conn) {
c, err := New(ctx, log.Logger, conn, TLSSkip, false, localhost, dns.Domain{ASCII: "mox.example"}, Opts{})
if err != nil {
panic(err)
}
msg := ""
err = c.Deliver(ctx, "postmaster@other.example", "mjl@mox.example", int64(len(msg)), strings.NewReader(msg), false, false, false)
var xerr Error
if err == nil || !errors.Is(err, ErrStatus) || !errors.As(err, &xerr) || xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrStatus with non-Permanent", err))
}
})
// A transaction is aborted. If we try another one, we should send a RSET.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250 mox.example")
s.readline("MAIL FROM:")
s.writeline("250 ok")
s.readline("RCPT TO:")
s.writeline("451 not now")
s.readline("RSET")
s.writeline("250 ok")
s.readline("MAIL FROM:")
s.writeline("250 ok")
s.readline("RCPT TO:")
s.writeline("250 ok")
s.readline("DATA")
s.writeline("550 not now")
}, func(conn net.Conn) {
c, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
if err != nil {
panic(err)
}
msg := ""
err = c.Deliver(ctx, "postmaster@other.example", "mjl@mox.example", int64(len(msg)), strings.NewReader(msg), false, false, false)
var xerr Error
if err == nil || !errors.Is(err, ErrStatus) || !errors.As(err, &xerr) || xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrStatus with non-Permanent", err))
}
// Another delivery.
err = c.Deliver(ctx, "postmaster@other.example", "mjl@mox.example", int64(len(msg)), strings.NewReader(msg), false, false, false)
if err == nil || !errors.Is(err, ErrStatus) || !errors.As(err, &xerr) || !xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrStatus with Permanent", err))
}
})
// Remote closes connection after 550 response to MAIL FROM in pipelined
// connection. Should result in permanent error, not temporary read error.
// E.g. outlook.com that has your IP blocklisted.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250-mox.example")
s.writeline("250 PIPELINING")
s.readline("MAIL FROM:")
s.writeline("550 ok")
}, func(conn net.Conn) {
c, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
if err != nil {
panic(err)
}
msg := ""
err = c.Deliver(ctx, "postmaster@other.example", "mjl@mox.example", int64(len(msg)), strings.NewReader(msg), false, false, false)
var xerr Error
if err == nil || !errors.Is(err, ErrStatus) || !errors.As(err, &xerr) || !xerr.Permanent {
panic(fmt.Errorf("got %#v, expected ErrStatus with Permanent", err))
}
})
// If we try multiple recipients and first is 452, it is an error and a
// non-pipelined deliver will be aborted.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250 mox.example")
s.readline("MAIL FROM:")
s.writeline("250 ok")
s.readline("RCPT TO:")
s.writeline("451 not now")
s.readline("RCPT TO:")
s.writeline("451 not now")
s.readline("QUIT")
s.writeline("250 ok")
}, func(conn net.Conn) {
c, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
if err != nil {
panic(err)
}
msg := ""
_, err = c.DeliverMultiple(ctx, "postmaster@other.example", []string{"mjl@mox.example", "mjl@mox.example"}, int64(len(msg)), strings.NewReader(msg), false, false, false)
var xerr Error
if err == nil || !errors.Is(err, errNoRecipients) || !errors.As(err, &xerr) || xerr.Permanent {
panic(fmt.Errorf("got %#v (%s) expected errNoRecipients with non-Permanent", err, err))
}
c.Close()
})
// If we try multiple recipients and first is 452, it is an error and a pipelined
// deliver will abort an allowed DATA.
run(t, func(s xserver) {
s.writeline("220 mox.example")
s.readline("EHLO")
s.writeline("250-mox.example")
s.writeline("250 PIPELINING")
s.readline("MAIL FROM:")
s.writeline("250 ok")
s.readline("RCPT TO:")
s.writeline("451 not now")
s.readline("RCPT TO:")
s.writeline("451 not now")
s.readline("DATA")
s.writeline("354 ok")
s.readline(".")
s.writeline("503 no recipient")
s.readline("QUIT")
s.writeline("250 ok")
}, func(conn net.Conn) {
c, err := New(ctx, log.Logger, conn, TLSOpportunistic, false, localhost, zerohost, Opts{})
if err != nil {
panic(err)
}
msg := ""
_, err = c.DeliverMultiple(ctx, "postmaster@other.example", []string{"mjl@mox.example", "mjl@mox.example"}, int64(len(msg)), strings.NewReader(msg), false, false, false)
var xerr Error
if err == nil || !errors.Is(err, errNoRecipientsPipelined) || !errors.As(err, &xerr) || xerr.Permanent {
panic(fmt.Errorf("got %#v (%s), expected errNoRecipientsPipelined with non-Permanent", err, err))
}
c.Close()
})
}
type xserver struct {
conn net.Conn
br *bufio.Reader
}
func (s xserver) check(err error, msg string) {
if err != nil {
panic(fmt.Errorf("%s: %w", msg, err))
}
}
func (s xserver) errorf(format string, args ...any) {
panic(fmt.Errorf(format, args...))
}
func (s xserver) writeline(line string) {
_, err := fmt.Fprintf(s.conn, "%s\r\n", line)
s.check(err, "write")
}
func (s xserver) readline(prefix string) {
line, err := s.br.ReadString('\n')
s.check(err, "reading command")
if !strings.HasPrefix(strings.ToLower(line), strings.ToLower(prefix)) {
s.errorf("expected command %q, got: %s", prefix, line)
}
}
func run(t *testing.T, server func(s xserver), client func(conn net.Conn)) {
t.Helper()
result := make(chan error, 2)
clientConn, serverConn := net.Pipe()
go func() {
defer func() {
serverConn.Close()
x := recover()
if x != nil {
result <- fmt.Errorf("server: %v", x)
} else {
result <- nil
}
}()
server(xserver{serverConn, bufio.NewReader(serverConn)})
}()
go func() {
defer func() {
clientConn.Close()
x := recover()
if x != nil {
result <- fmt.Errorf("client: %v", x)
} else {
result <- nil
}
}()
client(clientConn)
}()
var errs []error
for i := 0; i < 2; i++ {
err := <-result
if err != nil {
errs = append(errs, err)
}
}
if errs != nil {
t.Fatalf("errors: %v", errs)
}
}
func TestLimits(t *testing.T) {
check := func(s string, expLimits map[string]string, expMailMax, expRcptMax, expRcptDomainMax int) {
t.Helper()
limits, mailmax, rcptMax, rcptDomainMax := parseLimits([]byte(s))
if !reflect.DeepEqual(limits, expLimits) || mailmax != expMailMax || rcptMax != expRcptMax || rcptDomainMax != expRcptDomainMax {
t.Errorf("bad limits, got %v %d %d %d, expected %v %d %d %d, for %q", limits, mailmax, rcptMax, rcptDomainMax, expLimits, expMailMax, expRcptMax, expRcptDomainMax, s)
}
}
check(" unknown=a=b -_1oK=xY", map[string]string{"UNKNOWN": "a=b", "-_1OK": "xY"}, 0, 0, 0)
check(" MAILMAX=123 OTHER=ignored RCPTDOMAINMAX=1 RCPTMAX=321", map[string]string{"MAILMAX": "123", "OTHER": "ignored", "RCPTDOMAINMAX": "1", "RCPTMAX": "321"}, 123, 321, 1)
check(" MAILMAX=invalid", map[string]string{"MAILMAX": "invalid"}, 0, 0, 0)
check(" invalid syntax", nil, 0, 0, 0)
check(" DUP=1 DUP=2", nil, 0, 0, 0)
}
// Just a cert that appears valid. SMTP client will not verify anything about it
// (that is opportunistic TLS for you, "better some than none"). Let's enjoy this
// one moment where it makes life easier.
func fakeCert(t *testing.T, expired bool) tls.Certificate {
notAfter := time.Now()
if expired {
notAfter = notAfter.Add(-time.Hour)
} else {
notAfter = notAfter.Add(time.Hour)
}
privKey := ed25519.NewKeyFromSeed(make([]byte, ed25519.SeedSize)) // Fake key, don't use this for real!
template := &x509.Certificate{
SerialNumber: big.NewInt(1), // Required field...
DNSNames: []string{"mox.example"},
NotBefore: time.Now().Add(-time.Hour),
NotAfter: notAfter,
}
localCertBuf, err := x509.CreateCertificate(cryptorand.Reader, template, template, privKey.Public(), privKey)
if err != nil {
t.Fatalf("making certificate: %s", err)
}
cert, err := x509.ParseCertificate(localCertBuf)
if err != nil {
t.Fatalf("parsing generated certificate: %s", err)
}
c := tls.Certificate{
Certificate: [][]byte{localCertBuf},
PrivateKey: privKey,
Leaf: cert,
}
return c
}