OpenSSL-Universal` requires CocoaPods version `>= 1.9`, which is not satisfied by your current version, `1.8.4`. code example

Example 1: openssl universal requires cocoapods openssl-universal

pod 'OpenSSL-Universal'

Example 2: openssl universal requires cocoapods openssl-universal

pod 'OpenSSL-Universal', :git => 'https://github.com/krzyzanowskim/OpenSSL.git', :branch => :master