The company I work for has a number of internal web services accessible over HTTPS. These services use SSL/TLS certificates signed by an internal certificate authority which is only trusted by computers issued by my company. Occasionally, I need to access these services from my personal computer at home. Understandably, this triggers a security warning from my browser. Up until now I've just been ignoring those warnings, but recently I've started to feel a bit uncomfortable about that practice as it leaves my connection vulnerable to man in the middle attacks.
As a solution to this problem, I want to trust the root certificate used by my company on my computer at home. In keeping with the principle of least privilege however, I only want that CA to be trusted for domains my company controls, e.g. *.internal.examplecompany.com. How can I do this? The main computer I am interested in configuring this way is running Ubuntu 12.04 LTS. (I am also interested in doing this for other devices running Windows 8 and Android, but won't ask about those right now in order to avoid making this question too broad.)