For values lasting several lines (like your certificate), prefix each line after the first by a space or tab character. This space or tab character will be stripped by whatever you feed your ldif with.
userCertificate;binary:: MIIDdzCCAuCgAwIBAgIIEVQGxMF17akwDQYJKoZIhvcNAQEFBQAwfTEbMBkGCSqGSIb3DQEJARYMYm9iQGdyb3VwLm1kMRgwFgYDVQQDDA9Hcm91cE1EIFJvb3QgQ0Ex
but that gives me following errorError while importing LDIF- Record is invalid: Missing value type ':', '::' or ':<'javax.naming.NamingException: Record is invalid: Missing value type ':', '::' or ':<'