cURL Auth, TLS, and Proxy Security

curl --netrc https://example.com/protected

# Load login credentials from a `.netrc` file.

curl --netrc-file ./my.netrc https://example.com/protected

# Read machine credentials from a specific netrc file.

curl --digest -u 'user:password' https://example.com/protected

# Authenticate with Digest auth if the server supports it.

curl --negotiate -u : https://example.com/protected

# Use Negotiate auth with credentials from the environment or Kerberos setup.

curl --anyauth -u 'user:password' https://example.com/protected

# Let curl probe and select an auth scheme.

curl -L --location-trusted -u 'user:password' https://example.com/start

# Follow redirects and keep auth across hosts only when you explicitly trust it.

curl --tlsv1.2 https://example.com

# Require TLS 1.2 or newer for the connection.

curl --tls-max 1.3 https://example.com

# Cap the TLS protocol version used by curl.

curl --capath /etc/ssl/certs https://example.com

# Use a directory of CA certificates instead of a single bundle file.

curl --cert client.p12:mypassword --cert-type P12 https://mtls.example.com

# Authenticate with a P12 / PFX certificate bundle.

curl --pinnedpubkey sha256//BASE64HASH https://example.com

# Verify the server public key against a pinned key.

curl --crlfile revoked.pem https://example.com

# Check server certs against a CRL file.

curl --cert-status https://example.com

# Require certificate status validation via TLS stapling when supported.

curl --proxy-insecure -x https://proxy.example.com:8443 https://example.com

# Disable certificate verification for the HTTPS proxy connection.

curl -x http://proxy.example.com:8080 -U 'user:password' https://example.com

# Authenticate to a proxy with username and password.

curl -x https://proxy.example.com:8443 https://example.com

# Route traffic through an HTTPS proxy.

curl --proxy-cacert proxy-ca.pem -x https://proxy.example.com:8443 https://example.com

# Use a custom CA certificate file for the HTTPS proxy.

curl --proxy-cert proxy-client.crt --proxy-key proxy-client.key -x https://proxy.example.com:8443 https://example.com

# Send a client certificate when the proxy requires mTLS.

curl --proxytunnel -x http://proxy.example.com:8080 ftp://example.com/file.txt

# Use CONNECT tunneling for non-HTTP protocols when needed.