WARP is an outbound transparent SMTP proxy.
For redirect the port need by iptables rule:
iptables -t nat -A OUTPUT -p tcp --dport 25 -j DNAT --to-destination <proxy-ip>:<proxy-port>
Also, the MTA and Proxy must be on the same host to know the DST Address before NAT.
Usage
To check the operation, use the sandbox environment with the Vagrantfile in the repository.
warp main 🏄 make
env GOOS=linux GOARCH=amd64 go build -o warp ./cmd/warp/main.go
warp main 🏄 vagrant up
...
warp main 🏄 vagrant status
Current machine states:
sender running (virtualbox)
receiver running (virtualbox)
Start proxy on sender:
warp main 🏄 vagrant ssh sender
vagrant@sender:~$ /vagrant/warp -ip 192.168.30.30 -port 10025
2021/02/06 14:50:44 warp listens to 192.168.30.30:10025
Send mail on sender:
warp main 🏄 vagrant ssh sender
vagrant@sender:~$ smtp-source -m 1 -s 1 -l 10 -S 'Hi, Receiver from Sender' -f root@sender -t root@receiver localhost:25
Output by proxy on sender:
2021/02/06 14:50:48 connected from 192.168.30.40:57493
2021/02/06 14:50:48 connected to 192.168.30.50:25
2021/02/06 14:50:48 <- 220 receiver ESMTP Postfix (Ubuntu)\r\n
2021/02/06 14:50:48 -> EHLO sender\r\n
2021/02/06 14:50:48 |< 250-receiver\r\n250-PIPELINING\r\n250-SIZE 10240000\r\n250-VRFY\r\n250-ETRN\r\n250-STARTTLS\r\n250-ENHANCEDSTATUSCODES\r\n250-8BITMIME\r\n250-DSN\r\n250-SMTPUTF8\r\n250 CHUNKING\r\n
2021/02/06 14:50:48 <- 250-receiver\r\n250-PIPELINING\r\n250-SIZE 10240000\r\n250-VRFY\r\n250-ETRN\r\n250-ENHANCEDSTATUSCODES\r\n250-8BITMIME\r\n250-DSN\r\n250-SMTPUTF8\r\n250 CHUNKING\r\n
2021/02/06 14:50:48 |> STARTTLS\r\n
2021/02/06 14:50:48 >| MAIL FROM:<root@sender> SIZE=327\r\nRCPT TO:<root@receiver> ORCPT=rfc822;root@receiver\r\nDATA\r\n
2021/02/06 14:50:48 |< 220 2.0.0 Ready to start TLS\r\n
2021/02/06 14:50:48 |> EHLO sender\r\n
2021/02/06 14:50:48 pipe locked for tls connection
2021/02/06 14:50:48 |< 250-receiver\r\n250-PIPELINING\r\n250-SIZE 10240000\r\n250-VRFY\r\n250-ETRN\r\n250-ENHANCEDSTATUSCODES\r\n250-8BITMIME\r\n250-DSN\r\n250-SMTPUTF8\r\n250 CHUNKING\r\n
2021/02/06 14:50:48 tls connected, to pipe unlocked
2021/02/06 14:50:48 -> MAIL FROM:<root@sender> SIZE=327\r\nRCPT TO:<root@receiver> ORCPT=rfc822;root@receiver\r\nDATA\r\n
2021/02/06 14:50:48 <- 250 2.1.0 Ok\r\n250 2.1.5 Ok\r\n354 End data with <CR><LF>.<CR><LF>\r\n
2021/02/06 14:50:48 -> Received: from sender (localhost [127.0.0.1])\r\n by sender (Postfix) with SMTP id 45B113EA9B\r\n for <root@receiver>; Sat, 6 Feb 2021 14:50:48 +0000 (UTC)\r\nFrom: <root@sender>\r\nTo: <root@receiver>\r\nDate: Sat, 6 Feb 2021 14:50:48 +0000 (UTC)\r\nMessage-Id: <a77e.0003.0000@sender>\r\nSubject: Hi, Receiver from Sender\r\n\r\nXXXXXXXXXX\r\n.\r\nQUIT\r\n
2021/02/06 14:50:48 <- 250 2.0.0 Ok: queued as 76DAD4113D\r\n221 2.0.0 Bye\r\n
2021/02/06 14:50:48 connections closed
Received mail on receiver:
warp main 🏄 vagrant ssh receiver
vagrant@receiver:~$ sudo cat /var/spool/mail/root
From root@sender Fri Feb 5 16:00:41 2021
Return-Path: <root@sender>
X-Original-To: root@receiver
Delivered-To: root@receiver
Received: from receiver (proxy [192.168.30.30])
by receiver (Postfix) with ESMTPS id 3B9874160A
for <root@receiver>; Fri, 5 Feb 2021 16:00:41 +0000 (UTC)
Received: from sender (localhost [127.0.0.1])
by sender (Postfix) with SMTP id C08023E8E0
for <root@receiver>; Fri, 5 Feb 2021 16:00:01 +0000 (UTC)
From: <root@sender>
To: <root@receiver>
Date: Fri, 5 Feb 2021 16:00:01 +0000 (UTC)
Message-Id: <c2f05.0003.0000@sender>
Subject: Hi, Receiver from Sender
XXXXXXXXXX
Plugins
Warp outputs logs as stdout, but plugins can save logs to a database or a specified file.
Native Plugins:
- MySQL
export DSN="warp:PASSWORD@tcp(localhost:3306)/warp"
- SQLite
export DSN="/var/db/warp.sqlite3"
- File
export FILE_PATH="/tmp/warp.log"
warp main 🏄 vagrant ssh sender
vagrant@sender:~$ cd /vagrant
vagrant@sender:/vagrant$ make plugin && make
env GOOS=linux GOARCH=amd64 CGO_ENABLED=1 go build -buildmode=plugin -o .dist/mysql.so plugin/mysql/main.go
env GOOS=linux GOARCH=amd64 CGO_ENABLED=1 go build -buildmode=plugin -o .dist/file.so plugin/file/main.go
env GOOS=linux GOARCH=amd64 go build -o warp ./cmd/warp/main.go
vagrant@sender:/vagrant$ /vagrant/warp -ip 192.168.30.30 -port 10025
Run on vagrant:
vagrant@sender:/vagrant$ sudo mysql -uroot -D warp
mysql> select * from connections;
+----------------------------+-------------+---------------+----------------------------+
| id | mail_from | mail_to | occurred_at |
+----------------------------+-------------+---------------+----------------------------+
| 01FR74VW574PVQ5WGYE5RQATTG | root@sender | root@receiver | 2021-12-31 02:24:56.009302 |
| 01FR755XZKA594WA8SACQB4HC3 | root@sender | root@receiver | 2021-12-31 02:30:25.557302 |
+----------------------------+-------------+---------------+----------------------------+
2 rows in set (0.00 sec)
mysql> select communications.occurred_at, direction as d, substring(data, 1, 40) as data from communications, connections where connections.id = communications.connection_id and connections.id = "01FR755XZKA594WA8SACQB4HC3" order by communications.occurred_at;
+----------------------------+----+------------------------------------------+
| occurred_at | d | data |
+----------------------------+----+------------------------------------------+
| 2021-12-31 02:30:25.523678 | -- | connected to 192.168.30.50:25 |
| 2021-12-31 02:30:25.534128 | <- | 220 receiver ESMTP Postfix (Ubuntu)\r\n |
| 2021-12-31 02:30:25.534692 | -> | EHLO sender\r\n |
| 2021-12-31 02:30:25.535251 | <- | 250-receiver\r\n250-PIPELINING\r\n250-SI |
| 2021-12-31 02:30:25.535399 | |< | 250-receiver\r\n250-PIPELINING\r\n250-SI |
| 2021-12-31 02:30:25.538790 | -- | pipe locked for tls connection |
| 2021-12-31 02:30:25.538791 | |> | STARTTLS\r\n |
| 2021-12-31 02:30:25.538820 | >| | MAIL FROM:<root@sender> SIZE=327\r\nRCPT |
| 2021-12-31 02:30:25.539568 | |< | 220 2.0.0 Ready to start TLS\r\n |
| 2021-12-31 02:30:25.539701 | |> | EHLO sender\r\n |
| 2021-12-31 02:30:25.547124 | |< | 250-receiver\r\n250-PIPELINING\r\n250-SI |
| 2021-12-31 02:30:25.547459 | -- | tls connected, to pipe unlocked |
| 2021-12-31 02:30:25.547811 | -> | MAIL FROM:<root@sender> SIZE=327\r\nRCPT |
| 2021-12-31 02:30:25.554912 | <- | 250 2.1.0 Ok\r\n250 2.1.5 Ok\r\n354 End |
| 2021-12-31 02:30:25.555126 | -> | Received: from sender (localhost [127.0. |
| 2021-12-31 02:30:25.556812 | <- | 250 2.0.0 Ok: queued as 1EA19412C8\r\n22 |
| 2021-12-31 02:30:25.559877 | -- | connections closed |
+----------------------------+----+------------------------------------------+
17 rows in set (0.00 sec)
Author
linyows