{"id":17217,"date":"2017-02-15T14:25:53","date_gmt":"2017-02-15T19:25:53","guid":{"rendered":"http:\/\/mjtsai.com\/blog\/?p=17217"},"modified":"2025-07-08T21:57:45","modified_gmt":"2025-07-09T01:57:45","slug":"reverse-engineering-stickies-app","status":"publish","type":"post","link":"https:\/\/mjtsai.com\/blog\/2017\/02\/15\/reverse-engineering-stickies-app\/","title":{"rendered":"Reverse Engineering Stickies.app"},"content":{"rendered":"<p><a href=\"https:\/\/lowlevelbits.org\/reverse-engineering-stickies.app\/\">Alex Denisov<\/a>:<\/p>\n<blockquote cite=\"https:\/\/lowlevelbits.org\/reverse-engineering-stickies.app\/\">\n<p>The task becomes easy since the six colors are hardcoded in the binary. I just need to find where exactly and change the values to ones I like more.<\/p>\n<p>[&#8230;]<\/p>\n<p>What is important here: three consecutive values starting at <code>0x10000c790<\/code> moved to <code>xmm_<\/code> registers. I&rsquo;m not 100% sure, but I&rsquo;d assume that they are used to pass parameters into <code>colorWithDeviceRed:green:blue:alpha:<\/code>.<\/p>\n<p>[&#8230;]<\/p>\n<p>Now I know where the colors reside in code. I need to find them in the binary.\nThe address of a first color component is 0x10000c790. To find its on-disk address I need to subtract a base address from it.\nThe base address can be obtained via LLDB as well.<\/p>\n<p>[&#8230;]<\/p>\n<p>Now I can use xxd with -s (<code>--seek<\/code>) and -l (<code>--length<\/code>) parameters to get exactly 8 bytes at a given address.<\/p>\n<\/blockquote>","protected":false},"excerpt":{"rendered":"<p>Alex Denisov: The task becomes easy since the six colors are hardcoded in the binary. I just need to find where exactly and change the values to ones I like more. [&#8230;] What is important here: three consecutive values starting at 0x10000c790 moved to xmm_ registers. I&rsquo;m not 100% sure, but I&rsquo;d assume that they [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"apple_news_api_created_at":"2025-07-09T01:57:33Z","apple_news_api_id":"0520a81c-42a7-4323-bd2e-39abd887d848","apple_news_api_modified_at":"2025-07-09T01:57:33Z","apple_news_api_revision":"AAAAAAAAAAD\/\/\/\/\/\/\/\/\/\/w==","apple_news_api_share_url":"https:\/\/apple.news\/ABSCoHEKnQyO9Ljmr2IfYSA","apple_news_coverimage":0,"apple_news_coverimage_caption":"","apple_news_is_hidden":false,"apple_news_is_paid":false,"apple_news_is_preview":false,"apple_news_is_sponsored":false,"apple_news_maturity_rating":"","apple_news_metadata":"\"\"","apple_news_pullquote":"","apple_news_pullquote_position":"","apple_news_slug":"","apple_news_sections":"\"\"","apple_news_suppress_video_url":false,"apple_news_use_image_component":false,"footnotes":""},"categories":[4],"tags":[45,763,317,30,32,2792,1381,54,71,1482],"class_list":["post-17217","post","type-post","status-publish","format-standard","hentry","category-programming-category","tag-c","tag-hopper","tag-lldb","tag-mac","tag-macapp","tag-mach-o","tag-macos-10-12","tag-objective-c","tag-programming","tag-stickies"],"apple_news_notices":[],"_links":{"self":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/17217","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/comments?post=17217"}],"version-history":[{"count":1,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/17217\/revisions"}],"predecessor-version":[{"id":17218,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/17217\/revisions\/17218"}],"wp:attachment":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/media?parent=17217"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/categories?post=17217"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/tags?post=17217"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}