The flags for certificate verification operations. You can set flags like VERIFY_CRL_CHECK_LEAF by ORing them together. By default OpenSSL does neither require nor verify certificate revocation lists (CRLs).
>>> ssl.create_default_context().verify_flags <VerifyFlags.VERIFY_X509_TRUSTED_FIRST: 32768>
ssl/SSLContext.verify_flags
SSLContext.verify_flags