php curl请求微信发红包接口出现错误：Peer's Certificate issuer is not recognized.

PHP版本：5.6.29

openssl版本：OpenSSL 1.0.1e-fips 11 Feb 2013

请求微信发红包接口，curl错误提示：Peer's Certificate issuer is not recognized.

1）以前一直运行好好的，代码也没有变动

2）用户尝试多次提现，偶尔可行

CURL参数	说明
CURLOPT_SSLCERT	set SSL client certificate
CURLOPT_SSLKEY	specify private keyfile for TLS and SSL client cert
CURLOPT_CAINFO	path to Certificate Authority (CA) bundle

尝试的解决方案：

1）此种情况多发生在自签名的证书，报错含义是签发证书机构未经认证，无法识别。

解决办法是将签发该证书的私有CA公钥cacert.pem文件内容，追加到/etc/pki/tls/certs/ca-bundle.crt。

http://www.ipcpu.com/2014/12/curl-https-error/

经检查/etc/pki/tls/certs/ca-bundle.crt已包含微信发布的rootca.pem内容。

尝试去掉CURLOPT_CAINFO配置项，该选项配置的是微信给的rootca.pem

修改之后，没有出现Peer's Certificate issuer is not recognized.日志了，问题解决

查看 CURLOPT_CAINFO 的含义：

https://curl.haxx.se/libcurl/c/CURLOPT_CAINFO.html

注意到：For SSL engines that don't support certificate files the CURLOPT_CAINFO option is ignored. Refer to  https://curl.haxx.se/docs/ssl-compared.html