"Don't ask; don't tell"?
Seriously, I can't imagine a knife or bear spray would be an issue (even if it were Crocodile Dundee's knife). The only type of "weapon" they cover on the Canadian Customs site is firearms, so I'd think you are fine with a knife &/or bear spray. Then again, if they don't specifically ask about knives (I consider a knife a tool, not a "weapon"), I certainly wouldn't bring it up.
If you want to call for verification, the office is open from 8-4, Monday thru Friday (800 / 461-9999)
Note: Although it seems that you can buy bear bangers in any hardware store in Canada, I'm almost positive that it is illegal to return to the US with them (ATF considers them to be projectile explosives) so you may have to shoot them just to hear them go "boom" before going home. (I know... tragic, right?)