For those who are criminally inadmissible, the only way to enter Canada (other than a successful rehabilitation application) is to apply for a temporary resident permit.
Typically the applicant will use the criminal rehabilitation application forms but check the box that says “for information only.” However, some offices (such as Buffalo, NY) maintain their own temporary resident permit applications. Check with your local consulate to see which form is required.
Each consulate will have a list of supporting documents, however, they always include criminal record checks, a copy of the statute under which you were convicted, letters of reference, an explanation from you about the circumstances of the offense and subsequent steps you’ve taken since the offense, and proof that you completed your sentence. Additional supporting documents may be required depending on the circumstances.
As with any application for temporary residence, evidence of connections to your country are critical, and a purpose for visiting Canada should be stated, including length of time and how you will support yourself while in the country.