Curl HTTP Tool

Debug HTTP requests, inspect SSL certificates, and test endpoints using curl.

Tool Status

Tool installed: !command -v curl > /dev/null 2>&1 && echo "YES -- $(curl --version 2>/dev/null | head -1)" || echo "NO -- Install: apt install curl (Debian/Ubuntu) | brew install curl (macOS)"
Wrapper scripts available: !test -f scripts/curl/check-ssl-certificate.sh && echo "YES -- use wrapper scripts for structured JSON output" || echo "NO -- using standalone mode with direct commands"

Mode: Wrapper Scripts Available

If wrapper scripts are available (shown as YES above), prefer these commands. They provide structured JSON output and educational context.

SSL/TLS Inspection

bash scripts/curl/check-ssl-certificate.sh <target> -j -x -- Inspect certificate validity, expiry, TLS versions, cipher suites

HTTP Debugging

bash scripts/curl/debug-http-response.sh <target> -j -x -- Debug response timing, headers, redirects, and latency breakdown

Endpoint Testing

bash scripts/curl/test-http-endpoints.sh <target> -j -x -- Test HTTP methods (GET, POST, PUT, DELETE) and status codes

Learning Mode

bash scripts/curl/examples.sh <target> -- 10 common curl patterns with explanations

Always add -j for JSON output and -x to execute (vs display-only).

Mode: Standalone (Direct Commands)

If wrapper scripts are NOT available, use these direct curl commands.

SSL/TLS Inspection

Check certificate validity, expiry dates, TLS version support, and certificate chain of trust. Weak TLS versions (1.0, 1.1) have known vulnerabilities.

curl -vI https://<target> 2>&1 | grep -E 'subject:|issuer:|expire|SSL' -- View SSL certificate details
curl -vI https://<target> 2>&1 | grep 'expire date' -- Check certificate expiry date
curl --tlsv1.2 --tls-max 1.2 -sI https://<target> -o /dev/null -w 'TLS 1.2: HTTP %{http_code}\n' -- Test TLS 1.2 support
curl --tlsv1.3 -sI https://<target> -o /dev/null -w 'TLS 1.3: HTTP %{http_code}\n' -- Test TLS 1.3 support
curl -vI https://<target> 2>&1 | grep -E 'subject:|issuer:' -- Show certificate chain
curl -sI https://<target> | grep -i strict-transport-security -- Check HSTS header
curl --ciphers ECDHE-RSA-AES256-GCM-SHA384 -sI https://<target> -o /dev/null -w 'Cipher test: HTTP %{http_code}\n' -- Test specific cipher suite

HTTP Debugging

Diagnose slow requests by breaking down DNS lookup, TCP connect, TLS handshake, and time-to-first-byte. Pinpoint exactly where time is spent.

curl -I <target> -- Show response headers only (HEAD request)
curl -iL <target> -- Show headers and follow redirects
curl -v <target> 2>&1 | head -30 -- Verbose output with full request/response headers
curl -o /dev/null -s -w 'DNS: %{time_namelookup}s\nConnect: %{time_connect}s\nTLS: %{time_appconnect}s\nTTFB: %{time_starttransfer}s\nTotal: %{time_total}s\n' <target> -- Full timing breakdown
curl -o /dev/null -s -w 'TTFB: %{time_starttransfer}s\n' <target> -- Measure time-to-first-byte
curl -L -o /dev/null -s -w 'Redirects: %{num_redirects}\nTotal: %{time_total}s\n' <target> -- Show redirect chain timing

Endpoint Testing

Test how servers respond to different HTTP methods. Discover allowed methods, CORS policies, and authentication behavior.

curl -s -o /dev/null -w 'HTTP %{http_code}\n' <target> -- GET request status code
curl -X POST -d 'username=admin&password=test' -s -o /dev/null -w 'HTTP %{http_code}\n' <target> -- POST with form data
curl -X POST -H 'Content-Type: application/json' -d '{"key":"value"}' <target> -- POST with JSON body
curl -X OPTIONS -i -s <target> -- Discover allowed methods and CORS
curl -A 'Mozilla/5.0 (compatible; SecurityAudit/1.0)' -s -o /dev/null -w 'HTTP %{http_code}\n' <target> -- Custom User-Agent
curl -L -v -s -o /dev/null <target> 2>&1 | grep -E '< HTTP/|< location:' -- Follow and show redirect chain

Defaults

Target defaults to example.com (SSL) or https://example.com (HTTP scripts)
Target can be a domain name or full URL

Target Validation

All commands validate targets against .pentest/scope.json via the PreToolUse hook.