Demystify code signing and its importance in app development. Get help troubleshooting code signing issues and ensure your app is properly signed for distribution.

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Unable to run embedded binary due to quarantine
Hi! I've been scratching my brain for a few days now to no avail. I have a Perl project that I need to embed within my app. Perl includes a pp command (https://metacpan.org/pod/pp) which takes the runtime binary and then slaps the Perl code at the end of the binary itself which in brings some woes in a sense that the binary then needs to be "fixed" (https://github.com/rschupp/PAR-Packer/tree/master/contrib/pp_osx_codesign_fix) by removing the linker-provided signature and fixing LINKEDIT and LC_SYMTAB header sections of the binary. Nevertheless, I've successfully gotten the binary built, fixed up and codesigned it via codesign -s '$CS' mytool (where $CS is the codesigning identity). I can verify the signature as valid using codesign -v --display mytool: Identifier=mytool Format=Mach-O thin (arm64) CodeDirectory v=20400 size=24396 flags=0x0(none) hashes=757+2 location=embedded Signature size=4820 Signed Time=5. 1. 2026 at 8:54:53 PM Info.plist=not bound TeamIdentifier=XXXXXXX Sealed Resources=none Internal requirements count=1 size=188 It runs without any issues in Terminal, which is great. As I need to incorporate this binary in my app which is sandboxed, given my experience with other binaries that I'm including in the app, I need to codesign the binary with entitlements com.apple.security.app-sandbox and com.apple.security.inherit. So, I run: codesign -s '$CS' --force --entitlements ./MyTool.entitlements --identifier com.charliemonroe.mytool mytool ... where the entitlements file contains only the two entitlements mentioned above. Now I add the binary to the Xcode project, add it to the copy resources phase and I can confirm that it's within the bundle and that it's codesigned: codesign -vvvv --display MyApp.app/Contents/Resources/mytool Identifier=com.xxx.xxx.xxx Format=Mach-O thin (arm64) CodeDirectory v=20500 size=24590 flags=0x10000(runtime) hashes=757+7 location=embedded VersionPlatform=1 VersionMin=1703936 VersionSDK=1704448 Hash type=sha256 size=32 CandidateCDHash sha256=0a9f93af81e8e5cb286c3df6e638b2f78ab83a9e CandidateCDHashFull sha256=0a9f93af81e8e5cb286c3df6e638b2f78ab83a9edf463ce45d1cd3f89a6a4a00 Hash choices=sha256 CMSDigest=0a9f93af81e8e5cb286c3df6e638b2f78ab83a9edf463ce45d1cd3f89a6a4a00 CMSDigestType=2 Executable Segment base=0 Executable Segment limit=32768 Executable Segment flags=0x1 Page size=16384 CDHash=0a9f93af81e8e5cb286c3df6e638b2f78ab83a9e Signature size=4800 Authority=Apple Development: XXXXXX (XXXXXX) Authority=Apple Worldwide Developer Relations Certification Authority Authority=Apple Root CA Signed Time=9. 1. 2026 at 5:12:22 PM Info.plist=not bound TeamIdentifier=XXXXX Runtime Version=26.2.0 Sealed Resources=none Internal requirements count=1 size=196 codesign --display --entitlements :- MyApp.app/Contents/Resources/mytool <?xml version="1.0" encoding="UTF-8"?><!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "https://www.apple.com/DTDs/PropertyList-1.0.dtd"><plist version="1.0"><dict><key>com.apple.security.app-sandbox</key><true/><key>com.apple.security.inherit</key><true/></dict></plist> All seems to be in order! But not to Gatekeeper... Attempting to run this using the following code: let process = Process() process.executableURL = Bundle.main.url(forResource: "mytool", withExtension: nil)! process.arguments = arguments try process.run() process.waitUntilExit() Results in failure: process.terminationStatus == 255 Console shows the following issues: default 17:12:40.686604+0100 secinitd mytool[88240]: root path for bundle "<private>" of main executable "<private>" default 17:12:40.691701+0100 secinitd mytool[88240]: AppSandbox request successful error 17:12:40.698116+0100 kernel exec of /Users/charliemonroe/Library/Containers/com.charliemonroe.MyApp/Data/tmp/par-636861726c69656d6f6e726f65/cache-9c78515c29320789b5a543075f2fa0f8072735ae/mytool denied since it was quarantined by MyApp and created without user consent, qtn-flags was 0x00000086 Quarantine, hum? So I ran: xattr -l MyApp.app/Contents/Resources/mytool None listed. It is a signed binary within a signed app. There are other binaries that are included within the app and run just fine exactly this way (most of them built externally using C/C++ and then codesigned exectly as per above), so I really don't think it's an issue with the app's sandbox setup... Is there anyone who would be able to help with this? Thank you in advance!
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App Translocation Notes
App translocation, officially known as Gatekeeper path randomisation, comes up from time-to-time. The best resource to explain it, WWDC 2016 Session 706 What’s New in Security, is no longer available from Apple so I thought I’d post some notes here (r. 105455698 ). Questions or comments? Start a new thread here on DevForums, applying the Gatekeeper tag so that I see it. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" App Translocation Notes Gatekeeper path randomisation, more commonly known as app translocation, is a security feature on macOS 10.12 and later. When you run a newly downloaded app, the system executes the app from a randomised path. This prevents someone from taking an app that loads code from an app-relative path and repackaging it to load malicious code. IMPORTANT The best way to prevent your app from being tricked into loading malicious code is to enable library validation. You get this by default once you enable the hardened runtime. Do not disable library validation unless your app needs to load in-process plug-ins from other third-party developers. If you have an in-process plug-in model, consider migrating to ExtensionKit. The exact circumstances where the system translocates an app is not documented and has changed over time. It’s best to structure your app so that it works regardless of whether it’s translocated or not. App Translocation Compatibility Most apps run just fine when translocated. However, you can run into problems if you load resources relative to your app bundle. For example, consider a structure like this: MyApp.app Templates/ letter.myapp envelope.myapp birthday card.myapp Such an app might try to find the Templates directory by: Getting the path to the main bundle Navigating from that using a relative path This won’t work if the app is translocated. The best way to avoid such problems is to embed these resources inside your app (following the rules in Placing Content in a Bundle, of course). If you need to make them easily accessible to the user, add your own UI for that. For a great example of this, run Pages and choose File > New. App Translocation Limits There is no supported way to detect if your app is being run translocated. If you search the ’net you’ll find lots of snippets that do this, but they all rely on implementation details that could change. There is no supported way to determine the original (untranslocated) path of your app. Again, you’ll find lots of unsupported techniques for this out there on the ’net. Use them at your peril! If you find yourself using these unsupported techniques, it’s time to sit down and rethink your options. Your best option here is to make your app work properly when translocated, as illustrated by the example in the previous section. App Translocation in Action The following steps explain how to trigger app translocation on macOS 13.0. Keep in mind that the specifics of app translocation are not documented and have changed over time, so you might see different behaviour on older or new systems: To see app translocation in action: Use Safari to download an app that’s packaged as a zip archive. My go-to choice for such tests is NetNewsWire, but any app will work. Safari downloads the zip archive to the Downloads folder and then unpacks it (assuming your haven’t tweaked your preferences). In Finder, navigate to the Downloads folder and launch the app. When Gatekeeper presents its alert, approve the launch. In Terminal, look at the path the app was launched from: % ps xw | grep NetNewsWire … /private/var/folders/wk/bqx_nk71457_g9yry9c_2ww80000gp/T/AppTranslocation/C863FADC-A711-49DD-B4D0-6BE679EE225D/d/NetNewsWire.app/Contents/MacOS/NetNewsWire Note how the path isn’t ~/Downloads but something random. That’s why the official name for this feature is Gatekeeper path randomisation. Quit the app. Use Finder to relaunch it. Repeat step 5: % ps xw | grep NetNewsWire … /private/var/folders/wk/bqx_nk71457_g9yry9c_2ww80000gp/T/AppTranslocation/C863FADC-A711-49DD-B4D0-6BE679EE225D/d/NetNewsWire.app/Contents/MacOS/NetNewsWire The path is still randomised. Quit the app again. Use the Finder to move it to the desktop. And relaunch it. And repeat step 5 again: % ps xw | grep NetNewsWire … /Users/quinn/Desktop/NetNewsWire.app/Contents/MacOS/NetNewsWire The act of moving the app has cleared the state that triggered app translocation.
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"Application damaged and can't be opened' error prompt on 15.6.1 Sequoia
We have an application which keeps throwing the error "application is damaged and cannot be opened. You should move it to Trash" I have already referred to the documentation: https://developer.apple.com/forums/thread/706379 and https://developer.apple.com/forums/thread/706442 I have checked the following possible root causes: Codesign of the application using the codesign command Notarization of the application using the spctl command Executable permissions Checked for the presence of "com.apple.quarantine" flag for the application using xattr -l <path to executables" Checked the bundle structure None of the above listed items seemed to be a problem and are as expected. Can you please help us understand what could cause this issue and how to resolve this without recommending an uninstall/reinstall of the application?
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Signed App Opens But Doesn't Recognise Plugin
I have been trying to package a FileMaker 18 runtime app* for Mac distribution for - oh - a year and a half on and off (the Windows version was packaged in an afternoon). I succeeded - or thought I had - until I updated to Tahoe. Now my packaging process does everything it did formerly (creates the DMG, etc.), but when opened, fails to see/load a third-party plugin (BaseElements.fmplugin). Does anyone know why this should be? I have attached 4 of my build files in the hope that someone can point me in the right direction. Thanks in advance for any advice you may provide. Regards, L *Claris deprecated the runtime feature years ago, but it still runs and is useful for proof of concept. P.S. A contributor to an earlier query kindly suggested I go down the zip file or pkg installer route, rather than the DMG route. I tried doing as much but found both as susceptible to Mac spaghetti signage. build_all.txt repair_and_sign.txt build_dmg.txt notarize_dmg.txt
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Signed app can't be verified
I've signed an app, zipped it, and uploaded it to github. When I download it on another Mac, I get "it can't be opened because it could not be verified for malware". But on that computer, I can verify it with codesign, and it appears to be correct (as far as I can tell). I can copy/paste the app from my other Mac, and that copy will run without problem. sys_policy, however, gives: Notary Ticket Missing File: ReView.app Severity: Fatal Full Error: A Notarization ticket is not stapled to this application. Type: Distribution Error This is the same for the copy that runs, and the copy that doesn't. The difference between them appears to be a quarantine xattr. I can delete this, and the app launches without incident. Is this expected? Why should a signed app be quarantined just because it's been downloaded? The whole point of paying the fee is to avoid the security obstacles...! ;-)
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