{"id":552,"date":"2023-01-26T17:08:42","date_gmt":"2023-01-26T17:08:42","guid":{"rendered":"https:\/\/merserver.com\/?p=552"},"modified":"2023-01-26T17:08:43","modified_gmt":"2023-01-26T17:08:43","slug":"how-to-setup-an-sftp-server-with-rsa-public-key-authentication-mechanism","status":"publish","type":"post","link":"http:\/\/merserver.com\/index.php\/2023\/01\/26\/how-to-setup-an-sftp-server-with-rsa-public-key-authentication-mechanism\/","title":{"rendered":"How to setup an SFTP server with RSA public key authentication\u00a0mechanism"},"content":{"rendered":"\n

Why SFTP over FTP? The reason is visualized in its name: \u201cS\u201d, that means Security. Using SSH will employ a client-server model to authenticate two parties and encrypt the data between them. This topic will guide you through how to setup an <\/em>SFTP authentication mechanism using public key cryptography, the working OS is CentOS version 6.9. Let\u2019s get started!<\/em><\/p>\n\n\n\n

1. Make sure ssh and ssh-server are installed<\/h4>\n\n\n\n
user@localhost:$which ssh\n\/usr\/bin\/ssh<\/pre>\n\n\n\n
2. Create a new user and a new group in server<\/h4>\n\n\n\n
To be easier and clarified in permission managing, we should create a separated group for SFTP and add the corresponding user to the group. To acquire this, using the following groupadd and useradd command under root:<\/p>\n\n\n\n
user@localhost:$sudo groupadd sftp_users \nuser@localhost:$sudo useradd sftp_user1 <\/strong>\nuser@localhost:$sudo passwd sftp_user1\nuser@localhost:$sudo usermod -G sftp_users sftp_user1<\/pre>\n\n\n\n
3. Generate RSA public and private key<\/h4>\n\n\n\n
Let\u2019s make a recall how public key cryptography works. This link<\/a> for detail. In short, SSH key pairs can be used to authenticate a client to a server. The client creates a key pair and then uploads the public key to any remote server it wishes to access. This is placed in a file called authorized_keys<\/code> within the ~\/.ssh<\/code> directory in the user account\u2019s home directory on the remote server.<\/p>\n\n\n\n
If you\u2019re under *nix based OS, you can use ssh-keygen to generate keys as being described below. <\/p>\n\n\n\n
user@localhost:$ssh-keygen -t rsa -f sftp_rsa<\/pre>\n\n\n\n
Then, copy the public key to the server within the ~\/.ssh folder (corresponding to which user will be authenticated<\/strong>).<\/p>\n\n\n\n
user@localhost:$cd \/home\/sftp_user1<\/strong>\/ \nuser@localhost:$mkdir .ssh # In case of no .ssh folder inside\nuser@localhost:$ls -a\n...\n.ssh<\/strong>\n...\nuser@localhost:$cd .ssh # <= Copy the public key to this folder<\/pre>\n\n\n\n
4. Correct permissions and owner<\/h4>\n\n\n\n
user@localhost:$cd \/home\/sftp_user1<\/strong>\/\nuser@localhost:$chmod 700 .ssh \nuser@localhost:$chown sftp_user1:sftp_user1 .ssh \nuser@localhost:$cd .ssh mv sftp_rsa.pub authorized_keys\nuser@localhost:$chmod 600 authorized_keys\nuser@localhost:$chown sftp_user1:sftp_user1 authorized_keys<\/pre>\n\n\n\n
5. Change SSH configurations<\/h4>\n\n\n\n
user@localhost:$vi \/etc\/ssh\/sshd_config<\/pre>\n\n\n\n
Check the following configurations (uncomment these settings by removing # if needed):<\/p>\n\n\n\n
RSAAuthentication yes\nPubkeyAuthentication yes\nAuthorizedKeysFile .ssh\/authorized_keys\nPasswordAuthentication no<\/pre>\n\n\n\n
6. Restart the service<\/h4>\n\n\n\n
 user@localhost:$service sshd restart<\/pre>\n\n\n\n
Now you can check if it works by using any program that supports SFTP.<\/p>\n","protected":false},"excerpt":{"rendered":"
Why SFTP over FTP? The reason is visualized in its name: \u201cS\u201d, that means Security. Using SSH will employ a client-server model to authenticate two parties and encrypt the data between them. This topic will guide you through how to setup an SFTP authentication mechanism using public key cryptography, the working OS is CentOS version 6.9. Let\u2019s get…<\/p>\n
Read More “How to setup an SFTP server with RSA public key authentication\u00a0mechanism”<\/span> »<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-552","post","type-post","status-publish","format-standard","hentry","category-it"],"_links":{"self":[{"href":"http:\/\/merserver.com\/index.php\/wp-json\/wp\/v2\/posts\/552","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/merserver.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/merserver.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/merserver.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/merserver.com\/index.php\/wp-json\/wp\/v2\/comments?post=552"}],"version-history":[{"count":1,"href":"http:\/\/merserver.com\/index.php\/wp-json\/wp\/v2\/posts\/552\/revisions"}],"predecessor-version":[{"id":553,"href":"http:\/\/merserver.com\/index.php\/wp-json\/wp\/v2\/posts\/552\/revisions\/553"}],"wp:attachment":[{"href":"http:\/\/merserver.com\/index.php\/wp-json\/wp\/v2\/media?parent=552"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/merserver.com\/index.php\/wp-json\/wp\/v2\/categories?post=552"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/merserver.com\/index.php\/wp-json\/wp\/v2\/tags?post=552"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}