Implemented extract function for ldap search

Author: PythonHacker24

internal/search/extract.go

@@ -0,0 +1,82 @@
+package search
+
+import (
+	"crypto/tls"
+
+	"github.com/PythonHacker24/linux-acl-management-backend/config"
+	"github.com/go-ldap/ldap/v3"
+)
+
+/*
+	TODO: Blacklisting
+	This needs to be done when admin panel is created.
+	Users will be able to add users to blacklist which shouldn't be mentioned to the users.
+*/
+
+/* returns all users in LDAP server */
+func GetAllUsersFromLDAP() ([]User, error) {
+	
+	var l *ldap.Conn
+	var err error
+	ldapAddress := config.BackendConfig.Authentication.LDAPConfig.Address
+
+	/* check if TLS is enabled */
+	if config.BackendConfig.Authentication.LDAPConfig.TLS {
+		l, err = ldap.DialURL(ldapAddress, ldap.DialWithTLSConfig(&tls.Config{
+
+			/* true if using self-signed certs (not recommended) */
+			InsecureSkipVerify: true,
+		}))
+	} else {
+		l, err = ldap.DialURL(ldapAddress)
+	}
+
+	if err != nil {
+		return nil, err
+	}
+	defer l.Close()
+
+	/* authenticating with the ldap server with admin */
+	err = l.Bind(config.BackendConfig.Authentication.LDAPConfig.AdminDN,
+		config.BackendConfig.Authentication.LDAPConfig.AdminPassword,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	/* search for users */
+    searchRequest := ldap.NewSearchRequest(
+		/* Base DN */
+		config.BackendConfig.Authentication.LDAPConfig.AdminDN,
+        ldap.ScopeWholeSubtree,
+        ldap.NeverDerefAliases,
+		/* size limit */
+        0,     
+		/* time limit */
+        0,     
+		/* types only */
+        false, 
+		/* filter */
+        "(objectClass=person)",
+		/* attributes to retrieve */
+        []string{"cn", "mail", "sAMAccountName"}, // 
+        nil,
+    )
+
+	/* search for request in LDAP Server */
+    sr, err := l.Search(searchRequest)
+    if err != nil {
+        return nil, err
+    }
+
+    users := []User{}
+    for _, entry := range sr.Entries {
+        users = append(users, User{
+            CN:       entry.GetAttributeValue("cn"),
+            Mail:     entry.GetAttributeValue("mail"),
+            Username: entry.GetAttributeValue("sAMAccountName"),
+        })
+    }
+
+    return users, nil
+}