Description:
------------
One of the main attributes of an x509 certificate that is not parsed or exposed in openssl_x509_parse, is the signature type.  On a linux command line, running "cat my.pem|openssl x509 -noout -text" does provide the signature type, but there should be a native way in php to parse this out of a certificate without having to fallback to the command line.

Reading the source code, it looks like someone else tried to add it, but left it commented out, see: ext/openssl/openssl.c around line 1540...
/*
	add_assoc_long(return_value, "signaturetypeLONG", X509_get_signature_type(cert));
	add_assoc_string(return_value, "signaturetype", OBJ_nid2sn(X509_get_signature_type(cert)), 1);
	add_assoc_string(return_value, "signaturetypeLN", OBJ_nid2ln(X509_get_signature_type(cert)), 1);
*/
It was commented out, because the code did not work.  Perhaps there is a way to provide this functionality.

Test script:
---------------
<?php
$cert=<<<EOF
-----BEGIN CERTIFICATE-----
MIIBBzCBrgIJANZXs2GIGRy3MAoGCCqGSM49BAMDMAwxCjAIBgNVBAMMAXgwHhcN
MTQwNjA5MTczMjQ1WhcNMjQwNjA2MTczMjQ1WjAMMQowCAYDVQQDDAF4MFkwEwYH
KoZIzj0CAQYIKoZIzj0DAQcDQgAEK8KP9tJ1bZxLGKqNP9JpOkaq9paKoMS4/0wm
6u62b0mArY7xmS5/Nlkyi/GK21QpjSk4vRwkN+tYPeAy/8Bd2TAKBggqhkjOPQQD
AwNIADBFAiAjVRQZKlKCBzJxJ7aw8qRrZUhBczX9psneshOhI7g4mQIhAPlTbP67
mq9Qf/YphH6gWZXX50TGC2OTOUXRm60Cajs3
-----END CERTIFICATE-----
EOF;
$r = openssl_x509_parse($cert);
echo $r['signatureType']."\n";


Expected result:
----------------
string(23) "sha256WithRSAEncryption"


Actual result:
--------------
NULL