By default, the certificate is valid for 5 years. You can set any validity period with the -validityPeriod parameter.
Thanks - but somehow it doesn't work - i'm getting an error:
C:\Program Files (x86)\Adobe\Adobe Flash Builder 4\sdks\4.0.0 - AIR 2.0 Overlay\bin>adt -certificate -cn MySelfSign -o "MyCompany" -validityPeriod 20 2048-RSA C:\MySelfSign.p12 MyPassword
key type not recognized: -validityPeriod -- valid types are 1024-RSA and 2048-RSA
What's the problem here?
The validity period flag was added in AIR 2.5. It appears that you are still using AIR 2. (The latest version is 2.7.) If you still need AIR 2 for development, you can use a recent version of the SDK to generate the certificate. It should still work with the older SDK since the pkcs file is a standard format.