Curl HTTPS Diagnostic Commands

A quick reference table for common curl commands used to diagnose HTTPS connections, TLS handshakes, certificate validation, and proxy configurations.

Command	What It Does
curl -v https://host/	Performs full HTTPS request with verbose output (DNS, TCP, TLS handshake, certificate validation, HTTP response).
curl -I https://host/	Fetches only HTTP response headers.
curl -v --tlsv1.2 https://host/	Forces TLS 1.2 during handshake to test protocol compatibility.
curl -v --tlsv1.3 https://host/	Forces TLS 1.3 during handshake.
curl -vk https://host/	Skips certificate validation (insecure; for debugging only).
curl -v --cacert ca.pem https://host/	Uses a specific CA certificate file to validate the server certificate.
curl -v --capath /path/to/ca-dir https://host/	Uses a directory of CA certificates for validation.
curl -v --cert client.pem --key client.key https://host/	Performs mTLS using client certificate and private key.
curl -v --cert client.p12:password --cert-type P12 https://host/	Performs mTLS using PKCS12 client certificate file.
curl -v -x http://proxy:8080 https://host/	Sends HTTPS request through an HTTP proxy.
curl -v -x http://proxy:8080 -U user:pass https://host/	Sends HTTPS request through authenticated proxy.
curl -v --resolve host:443:IP https://host/	Bypasses DNS and forces connection to specific IP while preserving hostname (SNI).
curl -v --trace-time --trace-ascii trace.log https://host/	Writes detailed TLS and request trace logs to a file.
curl -o /dev/null -s -w "%{http_code}\n" https://host/	Returns only the HTTP status code.
curl -v -u user:pass https://host/api/system/ping	Tests HTTPS endpoint with Basic Authentication.
curl -v https://host/ 2>&1 | grep -i expire	Extracts certificate expiry details from verbose output.

tip

Replace host with your actual hostname (e.g., artifactory.yourcompany.com).