Initial commit

.env.default

@@ -0,0 +1,5 @@
+SMTP_HOSTNAME = "localhost"
+SMTP_PORT = "25"
+SMTP_DOMAIN = "example.com"
+LDAP_BASE = "dn=example,dn=com"
+LDAP_UID = "cn"

Makefile

@@ -0,0 +1,7 @@
+BINARY_NAME = fsldap
+
+build:
+	go build -v
+
+run: build
+	./$(BINARY_NAME)

README.org

@@ -0,0 +1,23 @@
+#+TITLE: Fake SMTP LDAP Server
+#+AUTHOR: czar
+
+A LDAP server that use SMTP as authentication source
+
+* Features
+  - LDAP BIND
+  - LDAP SEARCH
+
+* Build
+  fsldap is a written in Go, so you will need to install the Golang compiler
+  #+BEGIN_QUOTE
+  $ make build
+  #+END_QUOTE
+
+* Configuration
+  copy the =.env.default= to =.env= and set your variables accordly
+  
+* Running
+  #+BEGIN_QUOTE
+  $ make run
+  #+END_QUOTE
+  

config/main.go

@@ -0,0 +1,5 @@
+package config
+
+var SmtpHostname, SmtpPort, Domain, Base, Uid string
+var BaseLenght, UidLenght int
+

fsldap.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+
+	ldap "github.com/vjeantet/ldapserver"
+
+	"gt.kalli.st/czar/fsldap/config"
+	"gt.kalli.st/czar/fsldap/handler"
+	"gt.kalli.st/czar/fsldap/utils"
+)
+
+
+func init(){
+	log.Print("Loading vars...")
+	config.SmtpHostname = utils.Env("SMTP_HOSTNAME")
+	config.SmtpPort = utils.Env("SMTP_PORT")
+	config.Domain = utils.Env("SMTP_DOMAIN")
+	config.Base = utils.Env("LDAP_BASE")
+	config.Uid = utils.Env("LDAP_UID")
+	config.BaseLenght = len(config.Base) + 1
+	config.UidLenght = len(config.Uid) + 1
+}
+
+
+func main() {
+	server := ldap.NewServer()
+	routes := ldap.NewRouteMux()
+	routes.Bind(handler.Bind)
+	routes.Extended(handler.WhoAmI).
+		RequestName(ldap.NoticeOfWhoAmI).Label("Ext - WhoAmI")
+	routes.Search(handler.Search).Label("Search - Generic")
+	
+	server.Handle(routes)
+
+	log.Print("Starting FSLDAP server...")
+	go func(){
+		err :=  server.ListenAndServe("127.0.0.1:389")
+		if err != nil{
+			log.Fatal(err)
+		}
+	}()
+	ch := make(chan os.Signal)
+	signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM)
+	<-ch
+	close(ch)
+	server.Stop()
+}
+

go.mod

@@ -0,0 +1,9 @@
+module gt.kalli.st/czar/fsldap
+
+go 1.14
+
+require (
+	github.com/joho/godotenv v1.3.0 // indirect
+	github.com/lor00x/goldap v0.0.0-20180618054307-a546dffdd1a3 // indirect
+	github.com/vjeantet/ldapserver v1.0.1
+)

go.sum

@@ -0,0 +1,6 @@
+github.com/joho/godotenv v1.3.0 h1:Zjp+RcGpHhGlrMbJzXTrZZPrWj+1vfm90La1wgB6Bhc=
+github.com/joho/godotenv v1.3.0/go.mod h1:7hK45KPybAkOC6peb+G5yklZfMxEjkZhHbwpqxOKXbg=
+github.com/lor00x/goldap v0.0.0-20180618054307-a546dffdd1a3 h1:wIONC+HMNRqmWBjuMxhatuSzHaljStc4gjDeKycxy0A=
+github.com/lor00x/goldap v0.0.0-20180618054307-a546dffdd1a3/go.mod h1:37YR9jabpiIxsb8X9VCIx8qFOjTDIIrIHHODa8C4gz0=
+github.com/vjeantet/ldapserver v1.0.1 h1:3z+TCXhwwDLJC3pZCNbuECPDqC2x1R7qQQbswB1Qwoc=
+github.com/vjeantet/ldapserver v1.0.1/go.mod h1:YvUqhu5vYhmbcLReMLrm/Tq3S7Yj43kSVFvvol6Lh6k=

handler/ldap_handlers.go

@@ -0,0 +1,74 @@
+package handler
+
+import (
+	"crypto/tls"
+	"fmt"
+	"net/smtp"
+
+	"github.com/lor00x/goldap/message"
+	ldap "github.com/vjeantet/ldapserver"
+
+	"gt.kalli.st/czar/fsldap/config"
+	"gt.kalli.st/czar/fsldap/utils"
+)
+
+
+var smtpHost = config.SmtpHostname
+var smtpHostPort = fmt.Sprintf("%s:%s", smtpHost,config.SmtpPort)
+
+var tlsconfig = &tls.Config {
+        InsecureSkipVerify: true,
+	ServerName: smtpHost,
+}
+
+func Bind(w ldap.ResponseWriter, m *ldap.Message) {
+	r := m.GetBindRequest()
+	res := ldap.NewBindResponse(ldap.LDAPResultSuccess)
+	name := string(r.Name())
+	password := string(r.AuthenticationSimple())
+	user := utils.GetUser(name)
+	mail := utils.GetMail(user)
+	auth := smtp.PlainAuth("", mail, password, smtpHost)
+	client, error := smtp.Dial(smtpHostPort)
+	if error != nil {
+		res.SetResultCode(ldap.LDAPResultInvalidCredentials)
+		res.SetDiagnosticMessage("invalid credentials")
+		w.Write(res)
+		return
+	}
+	client.StartTLS(tlsconfig)
+	err := client.Auth(auth)
+	if err != nil {
+		res.SetResultCode(ldap.LDAPResultInvalidCredentials)
+		res.SetDiagnosticMessage("invalid credentials")
+		w.Write(res)
+		return
+	}
+	w.Write(res)
+}
+
+func WhoAmI(w ldap.ResponseWriter, m *ldap.Message) {
+	res := ldap.NewExtendedResponse(ldap.LDAPResultSuccess)
+	w.Write(res)
+}
+
+func Search(w ldap.ResponseWriter, m *ldap.Message) {
+	r := m.GetSearchRequest()	
+	select {
+	case <-m.Done:
+		return
+	default:
+	}
+	name := string(r.FilterString())
+	if name == ""{
+		return
+	}
+	user := utils.GetSearchUser(name)
+	mail := utils.GetMail(user)
+	attr := utils.GetLdapName(user)
+	entry := ldap.NewSearchResultEntry(attr)
+	entry.AddAttribute("mail", message.AttributeValue(mail))
+	w.Write(entry)	
+	response := ldap.NewSearchResultDoneResponse(ldap.LDAPResultSuccess)
+	w.Write(response)	
+}

utils/dotenv.go

@@ -0,0 +1,30 @@
+package utils
+
+import (
+	"log"
+	"os"
+
+	"github.com/joho/godotenv"
+)
+
+
+func init(){
+	loadEnv()
+}
+
+func loadEnv(){
+	log.Print("Loading .env file...")
+	err := godotenv.Load()
+	if err != nil {
+		log.Fatal("error loading .env file")
+	}
+}
+
+
+func Env(name string) string{
+	envVar := os.Getenv(name)
+	if envVar == "" {
+		log.Fatalf("error getting %s env variable", name)
+	}
+	return envVar
+}

utils/ldap.go

@@ -0,0 +1,29 @@
+package utils
+
+import (
+	"fmt"
+
+	"gt.kalli.st/czar/fsldap/config"
+)
+
+func GetMail(user string) string {
+	return fmt.Sprintf("%s@%s", user, config.Domain)
+}
+
+func GetLdapName(user string) string {
+	return fmt.Sprintf("%s=%s,%s", config.Uid, user, config.Base)
+}
+
+func GetUser(name string) string {
+	endIndex := len(name) - config.BaseLenght
+	user := name[config.UidLenght:endIndex]
+	return user
+}
+
+func GetSearchUser(name string) string {
+	startIndex := config.UidLenght + 1
+	endIndex := len(name) - 1
+	user := name[startIndex:endIndex]
+	return user
+}
+