CURLOPTSSLVERIFYPEER

CURLOPTSSLVERIFYPEER is a libcurl option that controls whether libcurl verifies the authenticity of the server's SSL certificate during an HTTPS connection. When this option is set to true (the default value), libcurl will check if the server's certificate is signed by a trusted Certificate Authority (CA) and if the certificate's hostname matches the server's hostname. This is a crucial security measure that helps prevent man-in-the-middle attacks by ensuring that the client is communicating with the intended server.

If CURLOPTSSLVERIFYPEER is set to false, libcurl will skip the certificate verification process. This means that libcurl will connect to the server even if the certificate is invalid, expired, or issued by an untrusted CA. While this can be useful in specific testing or development scenarios where valid certificates are not available, it significantly compromises security and should generally be avoided in production environments.

The verification process involves libcurl using a set of trusted CA certificates, often provided by the operating system or specified via CURL_CAINFO or CURL_CAPATH options. If the server's certificate cannot be validated against these trusted CAs, the connection will fail if CURLOPTSSLVERIFYPEER is true. It is strongly recommended to keep this option enabled for secure communication.