As a worst-case scenario, you could always just compile your own version of openssl as an RPM for your system, and then rpm -ihv.
EDIT: Starting with the source file (.tar.gz), here's what you want to do:
1) Create a new directory to house the RPM hierarchy.
# mkdir -p myopenssl/BUILD myopenssl/RPMS myopenssl/SOURCES myopenssl/SPECS myopenssl/SRPMS
2) Go into the SOURCES directory, and download your source openssl.tar.gz
# cd myopenssl/SOURCES
# mv openssl.tar.gz myopenssl/SOURCES/
3) Create a spec file that provides the necessary metadata (you will need to verify all the values are correct)
--- spec ----
%define _topdir /home/user/myopenssl
%define name openssl
%define release 0
%define version x.x
%define buildroot %{_topdir}/%{name}-%{version}-root
BuildRoot: %{buildroot}
Summary: openssl
License: GPL
Name: %{name}
Version: %{version}
Release: %{release}
Source: %{name}-%{version}.tar.gz
Prefix: /usr
Group: Development/Tools
%description
Special build of openssl for centos.
%prep
%setup -q
%build
./configure
make
%install
make install prefix=$RPM_BUILD_ROOT/usr
%files
%defattr(-,root,root)
/usr/local/bin/openssl
%doc %attr(0444,root,root) /usr/local/share/man/man1/openssl.1
4) After you have a spec file, use the rpmbuild command to build your RPM
# rpmbuild -v -bb --clean myopenssl/SPECS/openssl.spec
5) Your RPM is built at this point... use the following command to look at the contents:
# rpm -Vp RPMS/i386/myopenssl.i386.rpm
6) To install it, run the following as root:
# rpm -ihv myopenssl.i386.rpm
Hope this helps!
Best Answer
You first need to enable the CentOS repository.
By default, XenServer only enables the Citrix repository.
There are two ways to do this: permanently and temporarily.
I've blogged about this in some detail, so I'll just cut to the chase and give the recommended way, i.e., the temporary way: