new: if no smtp configuration is found arc will use the local sendmail binary (fixes #129)

README.md

@@ -132,7 +132,7 @@ It is necessary to change only the `username` and `password` access parameters o
 | scheduler.reports.rate\_limit | If two events of the same type are triggered in less than this number of seconds between one each other, the newest will not be notified by email. |
 | scheduler.reports.filter | Which type of events to report by email. |
 | scheduler.reports.to | Destination email address. |
-| scheduler.reports.smtp | SMTP server information. |
+| scheduler.reports.smtp | SMTP server information, if not provided the local sendmail binary will be used. |
 | scheduler.reports.pgp.enabled | If true, email notifications will be encrypted with PGP. |
 | scheduler.reports.pgp.keys.private | Path of the private key file to use to encrypt emails, if not found or empty it will be automatically generated by `arc`. |
 | scheduler.reports.pgp.keys.public | Path of the PGP public key of the email notifications recipient. |

config/config.go

@@ -42,6 +42,10 @@ type SMTPConfig struct {
 	Password string `json:"password"`
 }
 
+func (c SMTPConfig) Filled() bool {
+	return c.Address != ""
+}
+
 type KeyPair struct {
 	Public  string `json:"public"`
 	Private string `json:"private"`

events/mail.go

@@ -0,0 +1,81 @@
+package events
+
+import (
+	"bytes"
+	"crypto/tls"
+	"fmt"
+	"github.com/evilsocket/arc/config"
+	"github.com/evilsocket/arc/pgp"
+	"github.com/evilsocket/islazy/log"
+	"gopkg.in/gomail.v2"
+	"os"
+	"os/exec"
+)
+
+func doEmailReport(event Event) (err error) {
+	smtp := config.Conf.Scheduler.Reports.SMTP
+
+	contentType := "text/html"
+	reportType := "plaintext"
+	if pgpConf.Enabled {
+		reportType = "PGP encrypted"
+	}
+
+	body := event.Description
+	if pgpConf.Enabled {
+		contentType = "text/plain"
+		if err, body = pgp.Encrypt(body); err != nil {
+			return fmt.Errorf("could not PGP encrypt the message: %v", err)
+		}
+	}
+
+	log.Info("reporting %s event '%s' to %s ...",
+		reportType,
+		event.Title,
+		config.Conf.Scheduler.Reports.To)
+
+	if smtp.Filled() {
+		log.Info("using smtp server")
+
+		d := gomail.NewDialer(smtp.Address, smtp.Port, smtp.Username, smtp.Password)
+		d.TLSConfig = &tls.Config{InsecureSkipVerify: true}
+
+		m := gomail.NewMessage()
+		m.SetHeader("From", fmt.Sprintf("Arc Reporting System <%s>", smtp.Username))
+		m.SetHeader("To", config.Conf.Scheduler.Reports.To)
+		m.SetHeader("Subject", event.Title)
+
+		m.SetBody(contentType, body)
+
+		if err := d.DialAndSend(m); err != nil {
+			return err
+		}
+	} else if sendmailPath, err := exec.LookPath("sendmail"); err != nil {
+		return fmt.Errorf("error searching sendmail binary: %v", err)
+	} else {
+		log.Info("using %s", sendmailPath)
+
+		cmd := exec.Command(sendmailPath, "-t")
+
+		body = "From: arc@localhost\n" +
+			fmt.Sprintf("To: %s", config.Conf.Scheduler.Reports.To ) + "\n" +
+			fmt.Sprintf("Subject: %s", event.Title ) + "\n" +
+			fmt.Sprintf("Content-Type: %s", contentType ) + "\n" +
+			"Content-Transfer-Encoding: 7BIT\n" +
+			"Content-Disposition: inline\n" +
+			"MIME-Version: 1.0\n" +
+			"\n" +
+			body
+
+		buffer := bytes.Buffer{}
+		buffer.Write([]byte(body))
+
+		cmd.Stdin = &buffer
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+
+		return cmd.Run()
+	}
+
+	return nil
+}

events/main.go

@@ -8,13 +8,10 @@
 package events
 
 import (
-	"crypto/tls"
-	"fmt"
 	"github.com/evilsocket/arc/config"
-	"github.com/evilsocket/islazy/log"
 	"github.com/evilsocket/arc/pgp"
 	"github.com/evilsocket/arc/utils"
-	"gopkg.in/gomail.v2"
+	"github.com/evilsocket/islazy/log"
 	"sync"
 	"time"
 )
@@ -62,36 +59,8 @@ func Report(event Event) {
 		return
 	}
 
-	repotype := "plaintext"
-	if pgpConf.Enabled {
-		repotype = "PGP encrypted"
-	}
-
-	log.Info("Reporting %s event '%s' to %s ...", repotype, event.Title, config.Conf.Scheduler.Reports.To)
-
-	smtp := config.Conf.Scheduler.Reports.SMTP
-	d := gomail.NewDialer(smtp.Address, smtp.Port, smtp.Username, smtp.Password)
-	d.TLSConfig = &tls.Config{InsecureSkipVerify: true}
-
-	m := gomail.NewMessage()
-	m.SetHeader("From", fmt.Sprintf("Arc Reporting System <%s>", smtp.Username))
-	m.SetHeader("To", config.Conf.Scheduler.Reports.To)
-	m.SetHeader("Subject", event.Title)
-
-	var err error
-	ctype := "text/html"
-	body := event.Description
-	if pgpConf.Enabled {
-		ctype = "text/plain"
-		if err, body = pgp.Encrypt(body); err != nil {
-			log.Error("Could not PGP encrypt the message: %s.", err)
-		}
-	}
-
-	m.SetBody(ctype, body)
-
-	if err := d.DialAndSend(m); err != nil {
-		log.Error("Error: %s.", err)
+	if err := doEmailReport(event); err != nil {
+		log.Error("%v", err)
 	}
 }