CogniCrypt_gen: Generating code for the secure usage of crypto APIs

Many software applications are insecure because they misuse cryptographic APIs. Prior attempts to address misuses focused on detecting them after the fact. However, avoiding such misuses in the first place would significantly reduce development cost. In this paper,we present CogniCrypt_gen, a code generator that proactively assists developers in using Java crypto APIs correctly. CogniCrypt_gen accepts as input a code template and API-usage rules defined in the specification language CrySL. The code templates in CogniCrypt_gen are minimal, only comprising simple glue code. All security-sensitive code is generated fully automatically from the CrySL rules that the templates merely refer to. That way, generated code is provably correct and secure with respect to the CrySL definitions. CogniCrypt_gen supports the implementation of the most common cryptographic use cases, ranging from password-based encryption to digital signatures. We have empirically evaluated CogniCrypt_gen from the perspectives of both crypto-API developers and application developers. Our results show that CogniCrypt_gen is fast enough to be used during development. Compared to a stateof- the-art template-based solution, implementing use cases with CogniCrypt_gen requires only a fourth of development effort, without any additional language skills. Real-world developers see CogniCrypt_gen as significantly simpler to use than the same template-based solution.