Do not despair. You do not have to break the law to enjoy this masterpiece. Here are legitimate ways to access the text or a downloadable version.
To appreciate Setegar Gunung Batu, one must first understand its creator. Maria A. Sardjono was a prolific Indonesian author active from the 1950s through the 1980s. She was known for her powerful female protagonists and her ability to weave social commentary into compelling dramas.
Unlike many of her contemporaries who focused solely on romance, Sardjono tackled themes of poverty, class conflict, and moral integrity. Setegar Gunung Batu is arguably her magnum opus. It was first published in the era of rising print culture in Indonesia and quickly became a staple in school libraries and public readings.
The National Library of Indonesia (Perpusnas) has a digital app called iPusnas. Many classic novels have been digitized for registered members. Registration is free for Indonesian citizens. Search for "Setegar Gunung Batu" within the app. If available, you can "borrow" a digital copy that functions like a PDF for a limited time.