{"id":10822,"date":"2024-07-24T05:36:33","date_gmt":"2024-07-24T05:36:33","guid":{"rendered":"https:\/\/hostnoc-revamp.branex.org\/blog\/?p=10822"},"modified":"2026-05-19T07:14:23","modified_gmt":"2026-05-19T07:14:23","slug":"troubleshoot-ssh-permission-denied-publickey-error","status":"publish","type":"post","link":"https:\/\/hostnoc-revamp.branex.org\/blog\/troubleshoot-ssh-permission-denied-publickey-error\/","title":{"rendered":"8 Smart Fixes for SSH Permission Denied (PublicKey) Error"},"content":{"rendered":"<h2 data-start=\"308\" data-end=\"325\">Key Takeaways<\/h2>\n<ul data-start=\"327\" data-end=\"1010\">\n<li data-section-id=\"p07oud\" data-start=\"327\" data-end=\"435\">The \u201cPermission denied (publickey)\u201d error occurs when SSH fails to authenticate the provided public key.<\/li>\n<li data-section-id=\"1lolv2w\" data-start=\"436\" data-end=\"554\">SSH public key authentication works by verifying a private key against a matching public key stored on the server.<\/li>\n<li data-section-id=\"m0yfiw\" data-start=\"555\" data-end=\"675\">Missing or incorrectly configured <code data-start=\"591\" data-end=\"608\">authorized_keys<\/code> entries are among the most common causes of SSH access failures.<\/li>\n<li data-section-id=\"26k242\" data-start=\"676\" data-end=\"786\">Incorrect permissions on SSH directories, private keys, or configuration files can prevent authentication.<\/li>\n<li data-section-id=\"z7igv7\" data-start=\"787\" data-end=\"897\">Misconfigured SSH settings, SSH agent issues, or server-side authentication restrictions can block access.<\/li>\n<li data-section-id=\"7bafx5\" data-start=\"898\" data-end=\"1010\">Running SSH in verbose mode (<code data-start=\"929\" data-end=\"937\">ssh -v<\/code>) helps identify authentication problems and speeds up troubleshooting.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2>How to Fix SSH Permission Denied (PublicKey) Errors?<\/h2>\n<p>SSH Permission Denied (PublicKey) errors occur when your server cannot verify the public key used for authentication, blocking access to remote systems. This issue is often caused by missing or incorrectly configured keys, improper file permissions, or misconfigured SSH settings. By systematically checking your key placement, verifying permissions, and ensuring your SSH configuration is correct, you can quickly troubleshoot and resolve these errors to regain secure and reliable access to your server.<\/p>\n<p>&nbsp;<\/p>\n<h2><span style=\"font-weight: 400;\">Understanding the SSH Public Key Authentication<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Secure Shell uses public key cryptography to authenticate the user to the server. Here is how it works:<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">1. Generate Key Pair:<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The user generates a key pair on their local machine, consisting of a private key and a public key.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">2. Share Public Key:<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The user places the public key on the remote server in the `<\/span><b>~\/.ssh\/authorized_keys<\/b><span style=\"font-weight: 400;\">`file.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">3. Authenticate:<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">When connecting, the secure shell client uses the private key to create a signature that the server verifies using the public key.<\/span><\/p>\n<p><strong>Read more:\u00a0<a href=\"https:\/\/hostnoc-revamp.branex.org\/blog\/wordpress-403-forbidden-error\/\">WordPress 403 Forbidden Error: Everything You Need To Know<\/a><\/strong><\/p>\n<p><span style=\"font-weight: 400;\">If the server can verify the signature, it grants access. Otherwise, it denies access, often with the &#8220;<\/span><b>Permission denied (publickey)<\/b><span style=\"font-weight: 400;\">&#8221; message.<\/span><\/p>\n<p>&nbsp;<\/p>\n<h2><span style=\"font-weight: 400;\">Common Causes and Solutions<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Here are some of the common causes of the Secure Shell permission denied error.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">1. Missing or Incorrect Public Key on the Server<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The most common cause is that the public key is either not present or incorrectly configured on the server. Ensure your public key is correctly added to the `<\/span><b>~\/.ssh\/authorized_keys<\/b><span style=\"font-weight: 400;\">`file on the server.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Use the following command to append the key:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`bash<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0cat ~\/.ssh\/id_rsa.pub | ssh user@server &#8220;mkdir -p ~\/.ssh &amp;&amp; cat &gt;&gt; ~\/.ssh\/authorized_keys&#8221;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Verify the permissions and ownership of the `<\/span><b>~\/.ssh<\/b><span style=\"font-weight: 400;\">` directory and `<\/span><b>authorized_keys<\/b><span style=\"font-weight: 400;\">` file:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`bash<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0ssh user@server &#8220;chmod 700 ~\/.ssh; chmod 600 ~\/.ssh\/authorized_keys; chown -R user:user ~\/.ssh&#8221;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">2. Incorrect SSH Key Permissions<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Secure Shell requires that the private key file on your local machine has restricted permissions. If the permissions are too open, the secure shell will ignore the key. Ensure your private key has the correct permissions:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`bash<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0chmod 600 ~\/.ssh\/id_rsa<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">3. Incorrect SSH Configurations<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Sometimes, incorrect settings in your secure shell configuration files can cause authentication failures. Check your secure shell configuration file (`<\/span><b>~\/.ssh\/config<\/b><span style=\"font-weight: 400;\">`) for incorrect entries. It should look something like this:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`plaintext<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0Host server<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0HostName server_ip<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0User username<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0IdentityFile ~\/.ssh\/id_rsa<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Ensure there are no typos or incorrect paths.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">4. SSH Agent Issues<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Secure Shell agents might not be correctly handling your keys.\u00a0 Ensure your key is added to the secure shell agent:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`bash<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0ssh-add ~\/.ssh\/id_rsa<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Check if the agent is running by listing the keys it manages:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`bash<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0ssh-add -l<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`<\/span><\/p>\n<p><span style=\"font-weight: 400;\">If no keys are listed, add your key again.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">5. Server Configuration<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The secure shell daemon on the server might not be configured to accept public key authentication.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Check the server&#8217;s SSH configuration file (`<\/span><b>\/etc\/ssh\/sshd_config<\/b><span style=\"font-weight: 400;\">`) for the following entries:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`plaintext<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0PubkeyAuthentication yes<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0AuthorizedKeysFile .ssh\/authorized_keys<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`<\/span><\/p>\n<p><span style=\"font-weight: 400;\">If changes are made, restart the secure shell service:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`bash<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0sudo systemctl restart sshd<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">6. SELinux or AppArmor Restrictions<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Security modules like <\/span><b>SELinux<\/b><span style=\"font-weight: 400;\"> or <\/span><a href=\"https:\/\/apparmor.net\/\" target=\"_blank\" rel=\"noopener nofollow\"><b>AppArmor<\/b><\/a><b> <\/b><span style=\"font-weight: 400;\">might be restricting access to the <\/span><a href=\"https:\/\/hostnoc-revamp.branex.org\/blog\/why-you-should-setup-ssh-keys\/\"><span style=\"font-weight: 400;\">SSH keys<\/span><\/a><span style=\"font-weight: 400;\">. Temporarily disable SELinux to test if it is the cause:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`bash<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0sudo setenforce 0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`<\/span><\/p>\n<p><strong>Read more:\u00a0<a href=\"https:\/\/hostnoc-revamp.branex.org\/blog\/why-you-should-setup-ssh-keys\/\">7 Reasons Why You Should Set Up SSH Keys<\/a>\u00a0<\/strong><\/p>\n<p><span style=\"font-weight: 400;\">If it resolves the issue, review SELinux policies or AppArmor profiles to allow secure shell access.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">7. File System Issues<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">File system issues like corruption or misconfiguration might prevent the Secure Shell from reading the keys. Check the integrity and permissions of the home directory and the secure shell files:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`bash<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0ls -ld ~<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0ls -ld ~\/.ssh<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0&#8220;`<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">8. Debugging with Verbose Mode<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Use SSH&#8217;s verbose mode to gain more insight into the connection process and identify where it is failing:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">&#8220;`bash<\/span><\/p>\n<p><span style=\"font-weight: 400;\">ssh -v user@server<\/span><\/p>\n<p><span style=\"font-weight: 400;\">&#8220;`<\/span><\/p>\n<p><span style=\"font-weight: 400;\">This will provide detailed logs of the secure shell connection process, highlighting any issues with key recognition or authentication steps.<\/span><\/p>\n<p>&nbsp;<\/p>\n<h2><span style=\"font-weight: 400;\">Summary<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Troubleshooting the &#8220;<\/span><b>Permission denied (publickey)<\/b><span style=\"font-weight: 400;\">&#8221; error involves systematically checking each potential issue, from ensuring the correct public key placement and permissions to verifying secure shell configurations and server settings.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">By following the outlined steps, you can methodically identify and resolve the cause of the error, restoring your ability to securely connect to your remote server. Always remember to maintain proper security practices when handling the secure shell keys to prevent unauthorized access.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Did this article help you in troubleshooting the secure shell permission denied error for the public key? Share your feedback with us in the comments section below.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><strong><span class=\"highlight\" style=\"background-color:#971a1d;\">Attract speed, power, and control. Repel downtime and lag. Choose dedicated hosting.<\/span>\n<\/strong><\/p>\n<p style=\"text-align: center;\"><section class=\"dedicated_plans_section plans-section\" id=\"dedicated_plan\">\n    <table id=\"data\" class=\"stackable large-only\">\n        <thead>\n            <tr>\n<!--                 <th class=\"tbl-head-plan\">Plan<\/th> -->\n                <th class=\"tbl-head-cores\">Cores<\/th>\n                <th class=\"tbl-head-ram\">RAM<\/th>\n                <th class=\"tbl-head-storage\">Storage<\/th>\n                <th class=\"tbl-head-plan\">Location<\/th>\n                <th class=\"tbl-head-location\">Monthly Price<\/th>\n                <th class=\"tbl-head-link\">Link<\/th>\n            <\/tr>\n        <\/thead>\n        <tbody>\n        <tr><td colspan=\"6\">No products found.<\/td><\/tr>        <\/tbody>\n    <\/table>\n<\/section>\n    <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Key Takeaways The \u201cPermission denied (publickey)\u201d error occurs when SSH fails to authenticate the provided public key. SSH public key authentication works by verifying a private<span class=\"excerpt-hellip\"> [\u2026]<\/span><\/p>\n","protected":false},"author":13,"featured_media":10906,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"content-type":"","footnotes":""},"categories":[31],"tags":[],"class_list":["post-10822","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cybersecurity"],"acf":[],"_links":{"self":[{"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/posts\/10822","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/comments?post=10822"}],"version-history":[{"count":6,"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/posts\/10822\/revisions"}],"predecessor-version":[{"id":15813,"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/posts\/10822\/revisions\/15813"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/media\/10906"}],"wp:attachment":[{"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/media?parent=10822"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/categories?post=10822"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hostnoc-revamp.branex.org\/blog\/wp-json\/wp\/v2\/tags?post=10822"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}