From cbc78ad89196ce6e6fb5695ccdf3ee393d758e20 Mon Sep 17 00:00:00 2001
From: Alex Arce <19386312+alex-arce@users.noreply.github.com>
Date: Wed, 10 Mar 2021 09:01:02 +0100
Subject: [PATCH] Initial commit :-D

---
 LICENSE                     |  21 ++++++
 README.md                   |  18 +++++
 cmd/build.sh                |   1 +
 cmd/main.go                 |  50 ++++++++++++
 cmd/o365sender-example.conf |   4 +
 go.mod                      |   5 ++
 go.sum                      |   2 +
 o365sender.go               | 147 ++++++++++++++++++++++++++++++++++++
 8 files changed, 248 insertions(+)
 create mode 100644 LICENSE
 create mode 100644 README.md
 create mode 100644 cmd/build.sh
 create mode 100644 cmd/main.go
 create mode 100644 cmd/o365sender-example.conf
 create mode 100644 go.mod
 create mode 100644 go.sum
 create mode 100644 o365sender.go

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..e2f2b5f
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 Alex Arce
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..3dca5ab
--- /dev/null
+++ b/README.md
@@ -0,0 +1,18 @@
+# O365Sender
+Office 365 Mail tester
+
+#### Compilation
+
+Clone the repository:
+`git clone https://github.com/alex-arce/O365Sender`
+
+Build the binary:
+```
+cd cmd
+./build.sh
+```
+
+#### Usage
+```
+./O365Sender -config o365sender.conf --from="user@domain.com" --to="user@domain.com" --subject="TEST SUBJECT" --text="TEST BODY"
+```
diff --git a/cmd/build.sh b/cmd/build.sh
new file mode 100644
index 0000000..2042a34
--- /dev/null
+++ b/cmd/build.sh
@@ -0,0 +1 @@
+go build -o O365Sender
diff --git a/cmd/main.go b/cmd/main.go
new file mode 100644
index 0000000..a07e2ff
--- /dev/null
+++ b/cmd/main.go
@@ -0,0 +1,50 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+
+	o365 "github.com/alex-arce/O365Sender"
+	"github.com/BurntSushi/toml"
+)
+
+var configFilePath string
+
+var mailServerCfg *o365.MailServerConfig
+
+var from, to, subject, text string
+
+//var filenameToAttach string
+
+func main() {
+	fmt.Println("[O365 Mail sender]")
+
+	flag.StringVar(&configFilePath, "config", "o365sender.conf", "config location")
+
+	flag.StringVar(&from, "from", "", "FROM address")
+	flag.StringVar(&to, "to", "", "TO address")
+	flag.StringVar(&subject, "subject", "", "Subject")
+	flag.StringVar(&text, "text", "", "Mail text")
+	//flag.StringVar(&filenameToAttach, "filename", "", "filename to add")
+
+	flag.Parse()
+
+	if _, err := toml.DecodeFile(configFilePath, &mailServerCfg); err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	o365Client := o365.NewMailClient(mailServerCfg)
+
+	o365Client.AddFrom(from)
+	o365Client.AddTo(to)
+	o365Client.AddSubject(subject)
+	o365Client.AddBody(text)
+
+	sendError := o365Client.Send()
+	if sendError != nil {
+		fmt.Errorf("[-] ERROR sending mail :-(")
+	}
+
+	fmt.Println("[+] Mail Sent!!")
+}
diff --git a/cmd/o365sender-example.conf b/cmd/o365sender-example.conf
new file mode 100644
index 0000000..b31e5d3
--- /dev/null
+++ b/cmd/o365sender-example.conf
@@ -0,0 +1,4 @@
+Username = ""
+Password = ""
+Host = "outlook.office365.com"
+Port = "587"
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..e745e30
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,5 @@
+module github.com/alex-arce/O365Sender
+
+go 1.15
+
+require github.com/BurntSushi/toml v0.3.1
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..9cb2df8
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
diff --git a/o365sender.go b/o365sender.go
new file mode 100644
index 0000000..153e0b5
--- /dev/null
+++ b/o365sender.go
@@ -0,0 +1,147 @@
+package o365
+
+import (
+	"bytes"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"net"
+	"net/smtp"
+)
+
+type MailServerConfig struct {
+	Username string
+	Password string
+	Host     string
+	Port     string
+}
+
+func NewMailServerConfig(username, password, host, port string) *MailServerConfig {
+	return &MailServerConfig{
+		Username: username,
+		Password: password,
+		Host:     host,
+		Port:     port,
+	}
+}
+
+type Attachment struct {
+	filename string
+	data     []byte
+}
+
+type O365Client struct {
+	mailServerConfig *MailServerConfig
+	fromAddress      string
+	toAddress        []string
+	subject          string
+	body             []byte
+	attachments      []Attachment
+}
+
+func NewMailClient(cfgMail *MailServerConfig) *O365Client {
+	return &O365Client{
+		mailServerConfig: cfgMail,
+		fromAddress:      "",
+		toAddress:        nil,
+		subject:          "",
+		body:             nil,
+		attachments:      nil,
+	}
+}
+
+//-------------------------------------------------
+
+type loginAuth struct {
+	username, password string
+}
+
+func LoginAuth(username, password string) smtp.Auth {
+	return &loginAuth{username, password}
+}
+
+func (a *loginAuth) Start(server *smtp.ServerInfo) (string, []byte, error) {
+	return "LOGIN", []byte(a.username), nil
+}
+
+func (a *loginAuth) Next(fromServer []byte, more bool) ([]byte, error) {
+	if more {
+		switch string(fromServer) {
+		case "Username:":
+			return []byte(a.username), nil
+		case "Password:":
+			return []byte(a.password), nil
+		default:
+			return nil, errors.New("Unknown from server")
+		}
+	}
+	return nil, nil
+}
+
+//-------------------------------------------------
+
+func (oc *O365Client) AddFrom(fromAddress string) {
+	oc.fromAddress = fromAddress
+}
+
+func (oc *O365Client) AddTo(toAdd string) {
+	oc.toAddress = append(oc.toAddress, toAdd)
+}
+
+func (oc *O365Client) AddSubject(subject string) {
+	oc.subject = subject
+}
+
+func (oc *O365Client) AddBody(content string) {
+	var body bytes.Buffer
+	mimeHeaders := "MIME-version: 1.0;\nContent-Type: text/html; charset=\"UTF-8\";\n\n"
+	body.Write([]byte(fmt.Sprintf("Subject: %s\n%s\n\n", oc.subject, mimeHeaders)))
+	body.Write([]byte(content))
+	oc.body = body.Bytes()
+}
+
+func (oc *O365Client) AddAttachment(filename string) {
+	// TODO
+}
+
+func (oc *O365Client) Send() error {
+	server := fmt.Sprintf("%s:%s", oc.mailServerConfig.Host, oc.mailServerConfig.Port)
+
+	conn, err := net.Dial("tcp", server)
+	if err != nil {
+		println(err)
+		return err
+	}
+
+	c, err := smtp.NewClient(conn, oc.mailServerConfig.Host)
+	if err != nil {
+		println(err)
+		return err
+	}
+
+	tlsconfig := &tls.Config{
+		ServerName: oc.mailServerConfig.Host,
+	}
+
+	if err = c.StartTLS(tlsconfig); err != nil {
+		println(err)
+		return err
+	}
+
+	auth := LoginAuth(oc.mailServerConfig.Username, oc.mailServerConfig.Password)
+	if err = c.Auth(auth); err != nil {
+		println(err)
+		return err
+	}
+
+	var body bytes.Buffer
+	mimeHeaders := "MIME-version: 1.0;\nContent-Type: text/html; charset=\"UTF-8\";\n\n"
+	body.Write([]byte(fmt.Sprintf("Subject: %s\n%s\n\n", oc.subject, mimeHeaders)))
+	err = smtp.SendMail(oc.mailServerConfig.Host+":"+oc.mailServerConfig.Port, auth, oc.fromAddress, oc.toAddress, body.Bytes())
+	if err != nil {
+		fmt.Println(err)
+		return err
+	}
+
+	return nil
+}