(PHP 4 >= 4.0.6, PHP 5, PHP 7)



openssl_x509_checkpurpose ( mixed $x509cert , int $purpose [, array $cainfo = array() [, string $untrustedfile ]] ) : int

openssl_x509_checkpurpose() は証明書を調べ、 purpose で指定した目的に使用可能であるかどうかを確認します。





openssl_x509_checkpurpose() の目的
定数 説明
X509_PURPOSE_SSL_CLIENT この証明書を SSL 接続のクライアント側で使用できるか?
X509_PURPOSE_SSL_SERVER この証明書を SSL 接続のサーバー側で使用できるか?
X509_PURPOSE_NS_SSL_SERVER この証明書を Netscape SSL サーバーで使用できるか?
X509_PURPOSE_SMIME_SIGN この証明書を S/MIME email で使用できるか?
X509_PURPOSE_SMIME_ENCRYPT この証明書を S/MIME email の暗号化で使用できるか?
X509_PURPOSE_CRL_SIGN この証明書を証明書取消リスト(CRL)にサインをする際に使用できるか?
X509_PURPOSE_ANY この証明書をあらゆる用途に使用できるか?
これらのオプションはビットフィールドではありません。 指定できるのは一つだけです!


cainfo は、証明書の認証 で説明したような信頼できる CA ファイル/ディレクトリの配列です。


指定した場合は、これが証明書を含むPEMエンコードされたファイルの名前になります。 この証明書は、検証と証明を簡単化するために使用されます。 そのファイル内にある証明書は、信頼されない(untrusted)証明書とみなされます。


証明書が意図した目的に使用可能である場合に TRUE、使用できない場合に FALSE 、エラーの場合に -1 を返します。

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User Contributed Notes 3 notes

adr at NOSPAM dot entropymatrix dot com
7 years ago
The following is an example usage of openssl_x509_checkpurpose. It is equivalent to the openssl verify command as follows:
openssl verify -CApath $openssl_cadir -purpose sslserver $openssl_crtfile


$x509_res = openssl_x509_read(file_get_contents($openssl_crtfile));
$x509_res)) {
'x509 cert could not be read'."\n";
$valid = openssl_x509_checkpurpose($x509_res,X509_PURPOSE_SSL_SERVER,array($openssl_cadir));
if (
$valid === true) {
'Certificate is valid for use as SSL server'."\n";
} else {
'Certificate validation returned'.$valid."\n";
dingyuan at tencent dot com
4 days ago
in one word :if you set $purpose=0, you can use this function to verify certificate chain.


I want to verify a certificate chain. just like this:
userCert.pem => middleCert.pem => rootCert.pem

I figured that none of these openssl functions provide this function directly. And some friends have same need as me,  "mikey at badpenguins dot com" even write his own code to verify certificate chain(you can see notes below openssl_verify).

and I notice a note which has '-3' likes below openssl_verify, it says "validating an X509 certificate chain in php seems to be possible with openssl_x509_checkpurpose()", and I read the source code about this function, the given constant var about $purpose (like X509_PURPOSE_SSL_CLIENT ) is 1-7, and if you set $purpose among 1-7, you cannot verify the cert chain. Set $purpose=0 can get the truly result about verify a cert chain.

and I give that '-3' note a thumb-up, now it has -2 , lol.
chaoszcat at gmail dot com
7 years ago
Few days ago I dual boot my system into Windows 8 and play around with it, and then I boot it back to windows 7, and all of sudden this function fails by returning me 0 all the time.

Spent almost two hours digging google for no result, I almost end my research.

Then (I don't know why) I did a system time update (synchronize with, and all of sudden, this function returns me 1 (true).

It's true that when I boot back to Windows 7 my time has been screwed by a few hours later than my current time, and I did a manual change on it. I doubt this has anything to do with this function?

Hope it helps.

Keywords: google discovery, openid, discovery
Platform: Windows 7 64bit, PHP 5.3.13
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