Part two: Specifying HMAC in Cryptol

This is the last in a series of three blog posts detailing the use of SAW and Cryptol to prove the correctness of the HMAC implementation in Amazon’s s2n TLS library. Part one: Verifying s2n HMAC with SAW. Part three: Proving Program Equivalence with SAW. In the first post, we described how we proved equivalence between a mathematical description […]

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Part one: Verifying s2n HMAC with SAW

In June 2015, Amazon introduced its s2n library, an open-source TLS library that prioritizes simplicity. A stated benefit of this simplicity is ease of auditing and testing. Galois recently collaborated with Amazon to show that this benefit extends to verifiability by proving the correctness of s2n’s implementation of the keyed-Hash Message Authentication Code (HMAC) algorithm. To construct this […]

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