By choosing this menu option you can decode a potential ASN.1 document via the dialog ASN.1 PIN request.
The ASN.1 structure will be displayed in a new window in ASN.1 dump format if the chosen file is an ASN.1 document indeed.
If there exists a PSE within the ASN.1 document which is also containing a certificate, then the certificate will be displayed in another window in plain text format.
A proper information dialog is displayed if CrypTool cannot find any further ASN.1 structures.
Remark:
There is a certain chance that the PSE within the chosen ASN.1 document is PIN protected. In this case a PIN request dialog will prompt you for a correct PIN to assure that only authorized persons can access the certificate.