Other question show how you can sign an already signed IPA, like this, or this. Specially this part is what interests me:
/usr/bin/codesign -f -s "iPhone Distribution: Certificate Name" --resource-rules "Payload/Application.app/ResourceRules.plist" "Payload/Application.app"
Once I have the re-signed ipa, how can I see/know that in fact the IPA I currently have has been signed by "iPhone Distribution: Certificate Name"?