Simple code signature verification for OS X apps.

GRCodeSignatureVerifier can be used to check if an app has been tampered with by verifying It's code signature.

See demo app to learn more.

Read the docs.

Example

Swift

let verifier = GRCodeSignatureVerifier.sharedInstance()

// requirements are optional, but they make the verification stronger
verifier.codeRequirements = "identifier = \"com.yourcompany.AppName\""

if !verifier.isSignatureValid {
    NSLog("The app was modified. Exiting... \(verifier.validationError)")
    exit(1)
}

Objective-C

GRCodeSignatureVerifier *verifier = [GRCodeSignatureVerifier sharedInstance];

verifier.codeRequirements = @"identifier = \"com.yourcompany.AppName\"";

if (!verifier.isSignatureValid) {
    NSLog("The app was modified. Exiting... %@", verifier.validationError);
    exit(1);
}

Precompiled code requirements

You can use the tool csreq to compile code requirements:

$ csreq -r requirements.txt -b requirements.bin

To use precompiled code requirements you set the codeRequirementsData property:

verifier.codeRequirementsData = [NSData dataWithContentsOfFile:@"/path/to/requirements.bin"];

To learn more about what are code requirements and the code requirements language, check out this document from Apple.

Installing

Manually

Framework

Just download the code and add GRCodeSignatureVerifier.framework to the Embedded Binaries section of your app's target config.

Directly

Alternatively, you can just drop GRCodeSignatureVerifier.h and GRCodeSignatureVerifier.m in your app and use It directly.

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