Formal Verification of Security Protocol Implementations: A Survey

Automated formal verification of security protocols has been mostly focused on analyzing high-level abstract models which, however, are significantly different from real protocol implementations written in programming languages. Recently, some researchers have started investigating techniques that bring automated formal proofs closer to real implementations. This paper surveys these attempts, focusing on approaches that target the application code that implements protocol logic, rather than the libraries that implement cryptography. According to these approaches, libraries are assumed to correctly implement some models. The aim is to derive formal proofs that, under this assumption, give assurance about the application code that implements the protocol logic. The two main approaches of model extraction and code generation are presented, along with the main techniques adopted for each approac

Formally based semi-automatic implementation of an open security protocol

International audienceThis paper presents an experiment in which an implementation of the client side of the SSH Transport Layer Protocol (SSH-TLP) was semi-automatically derived according to a model-driven development paradigm that leverages formal methods in order to obtain high correctness assurance. The approach used in the experiment starts with the formalization of the protocol at an abstract level. This model is then formally proved to fulfill the desired secrecy and authentication properties by using the ProVerif prover. Finally, a sound Java implementation is semi-automatically derived from the verified model using an enhanced version of the Spi2Java framework. The resulting implementation correctly interoperates with third party servers, and its execution time is comparable with that of other manually developed Java SSH-TLP client implementations. This case study demonstrates that the adopted model-driven approach is viable even for a real security protocol, despite the complexity of the models needed in order to achieve an interoperable implementation

Provably correct Java implementations of Spi Calculus security protocols specifications

Spi Calculus is an untyped high level modeling language for security protocols, used for formal protocols specification and verification. In this paper, a type system for the Spi Calculus and a translation function are formally defined, in order to formalize the refinement of a Spi Calculus specification into a Java implementation. The Java implementation generated by the translation function uses a custom Java library. Formal conditions on such library are stated, so that, if the library implementation code satisfies such conditions, then the generated Java implementation correctly simulates the Spi Calculus specification. A verified implementation of part of the custom library is further presente

An Experiment in Interoperable Cryptographic Protocol Implementation Using Automatic Code Generation

Spi2Java is a tool that enables semi-automatic generation of cryptographic protocol implementations, starting from verified formal models. This paper shows how the last version of spi2Java has been enhanced in order to enable interoperability of the generated implementations. The new features that have been added to spi2Java are reported here. A case study on the SSH transport layer protocol, along with some experiments and measures on the generated code, is also provided. The case study shows, with facts, that reliable and interoperable implementations of standard security protocols can indeed be obtained by using a code generation tool like spi2Jav

Visual Model-Driven Design, Verification and Implementation of Security Protocols

A novel visual model-driven approach to security protocol design, verification, and implementation is presented in this paper. User-friendly graphical models are combined with rigorous formal methods to enable protocol verification and sound automatic code generation. Domain-specific abstractions keep the graphical models simple, yet powerful enough to represent complex, realistic protocols such as SSH. The main contribution is to bring together aspects that were only partially available or not available at all in previous proposal

Validating a Web Service Security Abstraction by Typing

An XML web service is, to a first approximation, an RPC service in which requests and responses are encoded in XML as SOAP envelopes, and transported over HTTP. We consider the problem of authenticating requests and responses at the SOAP-level, rather than relying on transport-level security. We propose a security abstraction, inspired by earlier work on secure RPC, in which the methods exported by a web service are annotated with one of three security levels: none, authenticated, or both authenticated and encrypted. We model our abstraction as an object calculus with primitives for defining and calling web services. We describe the semantics of our object calculus by translating to a lower-level language with primitives for message passing and cryptography. To validate our semantics, we embed correspondence assertions that specify the correct authentication of requests and responses. By appeal to the type theory for cryptographic protocols of Gordon and Jeffrey's Cryptyc, we verify the correspondence assertions simply by typing. Finally, we describe an implementation of our semantics via custom SOAP headers.Comment: 44 pages. A preliminary version appears in the Proceedings of the Workshop on XML Security 2002, pp. 18-29, November 200

Semantic and logical foundations of global computing: Papers from the EU-FET global computing initiative (2001–2005)

Overvew of the contents of the volume "Semantic and logical foundations of global computing