This can happen when you install RPMForge or other repos with the wrong architecture and here's how you fix it (simply uninstalling won't usually fix it):
solution
yum clean all
yum -y install openvpn
Loaded plugins: fastestmirror, presto
Loading mirror speeds from cached hostfile
* base: mirror.its.sfu.ca
* extras: centos.mirror.nexicom.net
* rpmforge: mirror.cpsc.ucalgary.ca
* updates: centos.arcticnetwork.ca
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package openvpn.x86_64 0:2.2.2-1.el5.rf will be installed
--> Processing Dependency: lzo for package: openvpn-2.2.2-1.el5.rf.x86_64
--> Processing Dependency: libcrypto.so.6()(64bit) for package: openvpn-2.2.2-1.el5.rf.x86_64
--> Processing Dependency: libssl.so.6()(64bit) for package: openvpn-2.2.2-1.el5.rf.x86_64
--> Processing Dependency: libpkcs11-helper.so.1()(64bit) for package: openvpn-2.2.2-1.el5.rf.x86_64
--> Processing Dependency: liblzo2.so.2()(64bit) for package: openvpn-2.2.2-1.el5.rf.x86_64
--> Running transaction check
---> Package lzo.x86_64 0:2.06-1.el5.rf will be installed
---> Package openssl098e.x86_64 0:0.9.8e-17.el6.centos.2 will be installed
---> Package pkcs11-helper.x86_64 0:1.08-1.el5.rf will be installed
--> Processing Dependency: libgnutls.so.13(GNUTLS_1_3)(64bit) for package: pkcs11-helper-1.08-1.el5.rf.x86_64
--> Processing Dependency: libgnutls.so.13()(64bit) for package: pkcs11-helper-1.08-1.el5.rf.x86_64
--> Finished Dependency Resolution
Error: Package: pkcs11-helper-1.08-1.el5.rf.x86_64 (rpmforge)
Requires: libgnutls.so.13()(64bit)
Error: Package: pkcs11-helper-1.08-1.el5.rf.x86_64 (rpmforge)
Requires: libgnutls.so.13(GNUTLS_1_3)(64bit)
You could try using --skip-broken to work around the problem
** Found 1 pre-existing rpmdb problem(s), 'yum check' output follows:
rpmforge-release-0.5.2-2.el6.rf.x86_64 is a duplicate with rpmforge-release-0.5.1-1.el5.rf.i386
yum -y install openvpn
Loaded plugins: fastestmirror, presto
Loading mirror speeds from cached hostfile
* base: mirror.its.sfu.ca
* extras: centos.mirror.nexicom.net
* rpmforge: mirror.cpsc.ucalgary.ca
* updates: centos.arcticnetwork.ca
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package openvpn.x86_64 0:2.2.2-1.el5.rf will be installed
--> Processing Dependency: lzo for package: openvpn-2.2.2-1.el5.rf.x86_64
--> Processing Dependency: libcrypto.so.6()(64bit) for package: openvpn-2.2.2-1.el5.rf.x86_64
--> Processing Dependency: libssl.so.6()(64bit) for package: openvpn-2.2.2-1.el5.rf.x86_64
--> Processing Dependency: libpkcs11-helper.so.1()(64bit) for package: openvpn-2.2.2-1.el5.rf.x86_64
--> Processing Dependency: liblzo2.so.2()(64bit) for package: openvpn-2.2.2-1.el5.rf.x86_64
--> Running transaction check
---> Package lzo.x86_64 0:2.06-1.el5.rf will be installed
---> Package openssl098e.x86_64 0:0.9.8e-17.el6.centos.2 will be installed
---> Package pkcs11-helper.x86_64 0:1.08-1.el5.rf will be installed
--> Processing Dependency: libgnutls.so.13(GNUTLS_1_3)(64bit) for package: pkcs11-helper-1.08-1.el5.rf.x86_64
--> Processing Dependency: libgnutls.so.13()(64bit) for package: pkcs11-helper-1.08-1.el5.rf.x86_64
--> Finished Dependency Resolution
Error: Package: pkcs11-helper-1.08-1.el5.rf.x86_64 (rpmforge)
Requires: libgnutls.so.13()(64bit)
Error: Package: pkcs11-helper-1.08-1.el5.rf.x86_64 (rpmforge)
Requires: libgnutls.so.13(GNUTLS_1_3)(64bit)
You could try using --skip-broken to work around the problem
** Found 1 pre-existing rpmdb problem(s), 'yum check' output follows:
rpmforge-release-0.5.2-2.el6.rf.x86_64 is a duplicate with rpmforge-release-0.5.1-1.el5.rf.i386
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