Specialized sites like ProDesignTools host authorized direct links to Adobe's own servers for CC 2017 installers.
Downloading Adobe InDesign CC 2017 for Mac for free as a full, permanent version is not legally possible through official channels. Adobe now supports and provides downloads only for the latest two versions of its Creative Cloud applications. Official Alternatives and Trials adobe indesign cc 2017 download mac free
While you specifically asked for the 2017 version, Adobe currently offers a free trial for the latest version of InDesign: 7-Day Free Trial : Available for individual users through the official Adobe website 14-Day Free Trial adobe indesign cc 2017 download mac free