ssl - Centos 5.11 OpenSSL TLS 1.2 for Paypal

I run a website on a server running Centos 5.11 - EOL now I know but an upgrade is not possible for a while. The website runs the Sellerdeck software which integrates with Paypal for payments.

In the next month or so Paypal will require me to be using TLS 1.2 [1] for connections to them, which is not supported by the default OpenSSL version installed in 5.11 (0.9.8b).

I have followed instructions [2] to install a second version of OpenSSL, and a second version of Curl linked to that new version of OpenSSL, which will support TLS 1.2, but it still doesn't pass the Paypal Test.

Centos 5.11 with OpenSSL 1.0.2k in /usr/local/:

/usr/local/bin/curl https://tlstest.paypal.com
curl: (35) Unknown SSL protocol error in connection to tlstest.paypal.com:443

Centos 6.9 with OpenSSL 1.0.1e-fips

curl https://tlstest.paypal.com
PayPal_Connection_OK

Can anyone help point me in the right direrction as to why the connection is not working with the updated OpenSSL?

Thanks very much

Kevin

1 - https://www.paypal-knowledge.com/infocenter/index?page=content&widgetview=true&id=FAQ1914&viewlocale=en_US

2 - https://miteshshah.github.io/linux/centos/how-to-enable-openssl-1-0-2-a-tlsv1-1-and-tlsv1-2-on-centos-5-and-rhel5/

Verbose non-working output:

/usr/local/bin/curl -Ivvv https://tlstest.paypal.com
* Rebuilt URL to: https://tlstest.paypal.com/
*   Trying 23.67.159.210...
* Connected to tlstest.paypal.com (23.67.159.210) port 443 (#0)
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/pki/tls/certs/ca-bundle.crt

  CApath: none
* TLSv1.0, TLS handshake, Client hello (1):
* Unknown SSL protocol error in connection to tlstest.paypal.com:443
* Closing connection 0
curl: (35) Unknown SSL protocol error in connection to tlstest.paypal.com:443

Verbose working output:

curl -Ivvv https://tlstest.paypal.com

* About to connect() to tlstest.paypal.com port 443 (#0)
*   Trying 23.214.50.150... connected
* Connected to tlstest.paypal.com (23.214.50.150) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
*   CAfile: /etc/pki/tls/certs/ca-bundle.crt
CApath: none
* SSL connection using TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
* Server certificate:
*       subject: CN=tlstest.paypal.com,OU=CDN Support,O="PayPal, Inc.",STREET=2211 N 1st St,L=San Jose,ST=California,postalCode=95131-2021,C=US,serialNumber=3014267,businessCategory=Private     Organization,incorporationState=Delaware,incorporationCountry=US
*       start date: Nov 06 00:00:00 2015 GMT

*       expire date: Oct 26 23:59:59 2017 GMT
*       common name: tlstest.paypal.com
*       issuer: CN=Symantec Class 3 EV SSL CA - G3,OU=Symantec Trust     Network,O=Symantec Corporation,C=US
> HEAD / HTTP/1.1
> User-Agent: curl/7.19.7 (i386-redhat-linux-gnu) libcurl/7.19.7 NSS/3.27.1     zlib/1.2.3 libidn/1.18 libssh2/1.4.2
> Host: tlstest.paypal.com
> Accept: */*
>
< HTTP/1.1 200 OK
HTTP/1.1 200 OK

< Content-Type: text/html
Content-Type: text/html
< Content-Length: 20
Content-Length: 20
< Date: Sat, 06 May 2017 12:58:47 GMT
Date: Sat, 06 May 2017 12:58:47 GMT
< Connection: keep-alive
Connection: keep-alive
<
* Connection #0 to host tlstest.paypal.com left intact

* Closing connection #0