From: Jesse Olson <j3s@c3f.net>
To: ~emersion/alps-dev@lists.sr.ht
Cc: Jesse Olson <j3s@c3f.net>
Subject: [PATCH] Set Message-Id header
Date: Tue,  4 Aug 2020 03:56:59 +0000
Message-Id: <20200804035659.5600-1-j3s@c3f.net>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable

---

Hi! I have personal interest in getting this patch upstream because it is=
 biting a few of my users.

This is a proof of concept Message-ID implementation, mostly for discussi=
on.

The format is partially gleaned from https://talk.begriffs.com/pipermail/=
friends/2020-August/001144.html

This patch doesn't work exactly as provided, but is a rough draft of the =
idea - I'm sure you'd like to see
generateMessageID moved to a different place, for example, but I wasn't s=
ure where. So, here are my questions.

todo: currently the domain isn't stripped from the from addr, but it shou=
ld be trivial to do.

0. do you want have plans for this or am i stepping on toes here?
1. would you like the helper functions moved to a different place? If so,=
 where?
2. would you prefer to encode in base70? I chose base64 because the stdli=
b makes it easy.

 plugins/base/smtp.go | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/plugins/base/smtp.go b/plugins/base/smtp.go
index 19c9e0b..8d0ba2b 100644
--- a/plugins/base/smtp.go
+++ b/plugins/base/smtp.go
@@ -3,9 +3,12 @@ package alpsbase
 import (
 	"bufio"
 	"bytes"
+	b64 "encoding/base64"
+	"encoding/binary"
 	"fmt"
 	"io"
 	"io/ioutil"
+	"math/rand"
 	"mime"
 	"mime/multipart"
 	"strings"
@@ -120,6 +123,21 @@ func writeAttachment(mw *mail.Writer, att Attachment=
) error {
 	return nil
 }
=20
+// Message-ID format is base64 encoded epoch.rand@example.com
+func generateMessageID(domain string) string {
+	epoch :=3D time.Now().Unix()
+	rand :=3D rand.Int63()
+
+	messageID :=3D base64Encode(epoch) + "." + base64Encode(rand) + domain
+	return messageID
+}
+
+func base64Encode(i int64) string {
+	buf :=3D make([]byte, 8)
+	binary.LittleEndian.PutUint64(buf, uint64(i))
+	return b64.URLEncoding.EncodeToString(buf)
+}
+
 func (msg *OutgoingMessage) WriteTo(w io.Writer) error {
 	from :=3D []*mail.Address{{"", msg.From}}
=20
@@ -138,7 +156,8 @@ func (msg *OutgoingMessage) WriteTo(w io.Writer) erro=
r {
 	if msg.InReplyTo !=3D "" {
 		h.Set("In-Reply-To", msg.InReplyTo)
 	}
-	// TODO: set Message-ID
+
+	h.Set("Message-ID", generateMessageID(msg.From))
=20
 	mw, err :=3D mail.CreateWriter(w, h)
 	if err !=3D nil {
--=20
2.28.0