CentOS PHP cURL NSS error 5938

it's general problem for curl compiled with NSS (only redhat-linuxes, debian and suse curl packages compiled without nss). you need compile curl from sources without nss-library.

so, i haven't solution how https-connections worked with nss-curl.

curl --version curl 7.29.0 (x86_64-redhat-linux-gnu) libcurl/7.29.0 NSS/3.14.3.0 zlib/1.2.7 libidn/1.26 libssh2/1.4.3 Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp scp sftp smtp smtps telnet tftp Features: AsynchDNS GSS-Negotiate IDN IPv6 Largefile NTLM NTLM_WB SSL libz

curl --version curl 7.25.0 (x86_64-suse-linux-gnu) libcurl/7.25.0 OpenSSL/1.0.1e zlib/1.2.7 libidn/1.25 libssh2/1.4.0 Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp scp sftp smtp smtps telnet tftp Features: AsynchDNS GSS-Negotiate IDN IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP

I encountered a similar "NSS error -5938" when using an outdated CentOS 6.x system to connect to an embedded device that stopped accepting TLS 1.0, only allowing TLS 1.1 and higher. The solution for me was to do a yum update. I saw these updates occurred:

---> Package curl.x86_64 0:7.19.7-46.el6 will be updated
---> Package curl.x86_64 0:7.19.7-52.el6 will be an update
...
---> Package nss.x86_64 0:3.21.0-0.3.el6_7 will be updated
---> Package nss.x86_64 0:3.21.3-2.el6_8 will be an update

I think this might be the specific change that helped:

$ rpm -q --changelog curl
[...]
* Mon Jan 11 2016 Kamil Dudka <[email protected]> 7.19.7-50
- use the default min/max TLS version provided by NSS (#1289205)