You need to pass the -k or --insecure option to the curl command. This option explicitly allows curl to perform “insecure” SSL connections and transfers. All SSL connections are attempted to be made secure by using the CA certificate bundle installed by default.
Does curl have a –no-check-certificate option like wget command on Linux?
The syntax is as follows that allows curl command to work with “insecure” or “invalid” SSL certificates without https certicates:
curl -k url curl --insecure url curl --insecure [options] url curl --insecure -I url
cURL ignore SSL certificate warnings command
In this example disable certificate verification for curl command:
curl --insecure -I https://202.54.1.2/
OR
curl -k -O https://202.54.1.2/file.tar.gz
Without the -k or --insecure option, you will get an error message that read as follows:
curl: (60) SSL certificate problem: Invalid certificate chain More details here: https://curl.haxx.se/docs/sslcerts.html curl performs SSL certificate verification by default, using a "bundle" of Certificate Authority (CA) public keys (CA certs). If the default bundle file isn't adequate, you can specify an alternate file using the --cacert option. If this HTTPS server uses a certificate signed by a CA represented in the bundle, the certificate verification probably failed due to a problem with the certificate (it might be expired, or the name might not match the domain name in the URL). If you'd like to turn off curl's verification of the certificate, use the -k (or --insecure) option.
Here is one useful example where you want to grab a file or see header info from remote host without using SSL enabled SNI domain name:
curl -O --insecure --header 'Host: www.example.com' -I https://207.5.1.10/file.html ### OR ### curl -k --header 'Host: www.example.com' -I https://207.5.1.10/file.html
Sample outputs:
Fig.01: Ignoring certificate warnings and saving the page or getting header info using curl command
How to apply the changes for all HTTPS connection
You can add insecure option to your $HOME/.curlrc file:
$ vi $HOME/.curlrc
Append the following:
insecure
Save and close the file. However, I do not recommend disabling SSL checks for all connections by default for security reasons.
How to specify CA to your trusted CA bundle for curl on the cli
One can try the following command for a self signed SSL/TLS certificates:
curl --cacert /pth/to/my/ca.pem https://url
curl --header 'Host: www.cyberciti.biz' --cacert /pth/to/my/ca.pem https://207.5.1.10/nixcraft.tar.gz
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I think it is important, whilst you are setting up your own services, to be able to connect even though you haven’t yet set up a proper certificate. With LetsEncrypt though, having curl permanently ignore security is particularly lazy.
The alternative of course is having your system trust your own CA.