Php/docs/openssl.purpose-check
From Get docs
Purpose checking flags
X509_PURPOSE_SSL_CLIENT(int)X509_PURPOSE_SSL_SERVER(int)X509_PURPOSE_NS_SSL_SERVER(int)X509_PURPOSE_SMIME_SIGN(int)X509_PURPOSE_SMIME_ENCRYPT(int)X509_PURPOSE_CRL_SIGN(int)X509_PURPOSE_ANY(int)
