curl_getinfo($ch, CURLINFO_CERTINFO) 为空

我有 PHP 7.2IUS https://ius.io/GettingStarted/存储库，但默认 PHP (CentOS 7.x) 上的行为相同。

Code:

$domain = "google.com";

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://' . $domain);
curl_setopt($ch, CURLOPT_CERTINFO, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_NOBODY, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
curl_setopt($ch, CURLOPT_VERBOSE, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_VERBOSE, 1);

curl_exec($ch);
$certInfo = curl_getinfo($ch, CURLINFO_CERTINFO);

curl_close($ch);

多变的$certInfo是空的。我已经测试了卷曲https://www.howsmyssl.com/a/check https://www.howsmyssl.com/a/check并且它支持 TLS 1.2。

OpenSSL 1.0.2k-fips
cURL support => enabled
cURL Information => 7.29.0
Age => 3
Features
AsynchDNS => Yes
CharConv => No
Debug => No
GSS-Negotiate => Yes
IDN => Yes
IPv6 => Yes
krb4 => No
Largefile => Yes
libz => Yes
NTLM => Yes
NTLMWB => Yes
SPNEGO => No
SSL => Yes
SSPI => No
TLS-SRP => No
Protocols => dict, file, ftp, ftps, gopher, http, https, imap, imaps, ldap, ldaps, pop3, pop3s, rtsp, scp, sftp, smtp, smtps, telnet, tftp
Host => x86_64-redhat-linux-gnu
SSL Version => NSS/3.36
ZLib Version => 1.2.7
libSSH Version => libssh2/1.4.3

怎么了？卷曲？开放式SSL？国家安全局？

尝试一下：（更新的域）

$domain = "www.google.com";

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://' . $domain);
curl_setopt($ch, CURLOPT_CERTINFO, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_NOBODY, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
curl_setopt($ch, CURLOPT_VERBOSE, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_VERBOSE, 1);

curl_exec($ch);
$certInfo = curl_getinfo($ch, CURLINFO_CERTINFO);

curl_close($ch);