Tools
Reference to these tools is solely for the information and convenience of the public, and does not constitute the endorsement or recommendation of any company, product, or service by the CA/Browser Forum.
Online Tests of SSL/TLS Configurations (submit website to check)
CryptCheck – https://cryptcheck.fr / https://tls.imirhil.fr/
DigiCert – https://www.digicert.com/help/
Hardenize – https://www.hardenize.com/
Immuniweb – https://www.immuniweb.com/ssl/
Mozilla Observatory – https://observatory.mozilla.org
Scanigma – https://scanigma.com/
SSL Checker – https://www.sslchecker.com/sslchecker
SSL Labs – https://www.ssllabs.com/ssltest
SSLyze – https://github.com/nabla-c0d3/sslyze
TestSSL – https://testssl.sh/
Wormly – https://www.wormly.com/test_ssl
Actalis SSL Check – https://sslcheck.actalis.com/
Browser / Client Testing
BadSSL – https://badssl.com/ (numerous scenarios to use to test how your browser reacts)
How’s My SSL – https://www.howsmyssl.com/
SSL Labs – https://clienttest.ssllabs.com:8443/ssltest/viewMyClient.html
Check for Bad Private Keys
Hanno Boeck‘s Tool – https://github.com/badkeys/badkeys
ROCA Vulnerability – https://github.com/crocs-muni/roca
CVE-2008-0166 – https://github.com/CVE-2008-0166 provides a generator that runs on modern 64-bit Linux systems and provides complete sets of pregenerated keys for the most common RSA key sizes
Debian Weak Keys – https://github.com/HARICA-official/debian-weak-keys provides a generator, for a subset of the parameters listed above, that can take advantage of a computer cluster
Check Certificates and CSRs (Searches and Decoders)
Crt.sh - https://crt.sh/?sha256= [sha256 hash of certificate]
Censys.io – https://search.censys.io/certificates (billions of certificates)
GoDaddy Certificate and CSR Decoders – https://ssltools.godaddy.com/views/csrDecoder / https://ssltools.godaddy.com/views/certDecoder
Mozilla Certsplainer – https://tls-observatory.services.mozilla.com/static/certsplainer.html (Shows certificate information and shows path to root certificate (requires certificate PEM file))
Mozilla EV certificate checker – https://tls-observatory.services.mozilla.com/static/ev-checker.html (requires certificate PEM and EV OID)
Sectigo – https://secure.sectigo.com/utilities/decodeCSR.html
CA Information
Status of each CA’s three test websites
Crt.sh – https://crt.sh/test-websites
Status of CAs’ CCADB reporting compliance
Crt.sh – https://crt.sh/apple-disclosures
Crt.sh – https://crt.sh/chrome-disclosures
Crt.sh – https://crt.sh/mozilla-disclosures
CA Misissuance
Coming soon
Revocation Checking
Revocation Checker – https://certificate.revocationcheck.com/
Certificate Tools OCSP Checker – https://certificatetools.com/ocsp-checker
OCSP Watch – https://sslmate.com/labs/ocsp_watch/
CRL Watch – https://sslmate.com/labs/crl_watch/
Linting Software
pkilint - Opensource linting framework for documents that are encoded using ASN.1 (coverage includes PKIX, S/MIME BR, TLS BR, CRL and OCSP response, etc.) - https://github.com/digicert/pkilint
ZLint - Opensource X.509 certificate linter written in Go that checks for consistency with standards (e.g. RFC 5280) and other relevant PKI requirements (e.g. CA/Browser Forum Baseline Requirements) - https://github.com/zmap/zlint
pkimetal - Opensource PKI “meta linter” that integrates pkilint, Zlint, and several other linters behind a simple REST API, which supports pre-issuance and post-issuance linting of certificates, CRLs, and OCSP responses - https://github.com/pkimetal/pkimetal
Offline, Downloadable Tools
OpenSSL – https://www.openssl.org/
How to check OCSP using OpenSSL – https://unmitigatedrisk.com/?p=42
OWASP SSL advanced forensic tool (O-Saft) https://owasp.org/www-project-o-saft/
ASN.1 Viewers – https://www.itu.int/en/ITU-T/asn1/Pages/Tools.aspx
Server Configuration and Recommended TLS Deployment Practices
Mozilla SSL/TLS Configuration Generator for Servers (Apache, nginx, etc.) – https://ssl-config.mozilla.org/
SSL Labs: SSL and TLS Deployment Best Practices – https://github.com/ssllabs/research/wiki/SSL-and-TLS-Deployment-Best-Practices
OWASP TLS Cheat Sheet – https://cheatsheetseries.owasp.org/cheatsheets/Transport_Layer_Security_Cheat_Sheet.html