(PHP 4 >= 4.0.6)openssl_x509_checkpurpose -- Verifies if a certificate can be used for a particular purpose
Descriptionbool openssl_x509_checkpurpose ( mixed x509cert, int purpose, array cainfo [, string untrustedfile])
Returns TRUE if the certificate can be used for the intended purpose, FALSE if it cannot, or -1 on error.
openssl_x509_checkpurpose() examines the certificate specified by x509cert to see if it can be used for the purpose specified by purpose.
cainfo should be an array of trusted CA files/dirs as described in Certificate Verification.
untrustedfile, if specified, is the name of a PEM encoded file holding certificates that can be used to help verify the certificate, although no trust in placed in the certificates that come from that file.
These options are not bitfields - you may specify one only!
表格 1. openssl_x509_checkpurpose() purposes