codesign

The codesign command line tool is used in macOS to sign applications and other executable files. It is primarily used for code integrity checks and security purposes.

This command allows developers to digitally sign their software to ensure its authenticity and integrity.

When an application is signed using codesign, it binds a unique cryptographic signature to the executable, making it tamper-proof.

The codesign tool verifies the validity of the application's signature, checking if it has been modified or tampered with since the signing process.

It utilizes digital certificates issued by Apple or trusted third-party certificate authorities to establish the authenticity of the software.

codesign also supports various options to customize the signing process, including specifying entitlements and resource rules, which control the privileges and resources the signed application can access.

In addition to signing applications, codesign can also be used to verify code signatures, display signing information, and revoke signatures if necessary.