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arXiv · 1708.08542

Verified Correctness and Security of mbedTLS HMAC-DRBG

Katherine Q. Ye·Matthew Green·Naphat Sanguansin·Lennart Beringer·Adam Petcher·Andrew W. Appel
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Abstract

We have formalized the functional specification of HMAC-DRBG (NIST 800-90A), and we have proved its cryptographic security--that its output is pseudorandom--using a hybrid game-based proof. We have also proved that the mbedTLS implementation (C program) correctly implements this functional specification. That proof composes with an existing C compiler correctness proof to guarantee, end-to-end, that the machine language program gives strong pseudorandomness. All proofs (hybrid games, C program verification, compiler, and their composition) are machine-checked in the Coq proof assistant. Our proofs are modular: the hybrid game proof holds on any implementation of HMAC-DRBG that satisfies our functional specification. Therefore, our functional specification can serve as a high-assurance reference.

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Katherine Q. Ye, Matthew Green, Naphat Sanguansin, Lennart Beringer, Adam Petcher, Andrew W. Appel. 2017-08-28. Verified Correctness and Security of mbedTLS HMAC-DRBG. https://doi.org/10.1145/3133956.3133974

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