libsparkcrypto is a formally verified implementation of several widely used
symmetric cryptographic algorithms using the SPARK programming language and
toolset. For the complete library proofs of the absence of run-time errors
like type range violations, division by zero and numerical overflows are
available. Some of its subprograms include proofs of partial correctness.

The distribution contains test cases for all implemented algorithms and a
benchmark to compare its performance with the OpenSSL library. The achieved
speed has been found to be very close to the optimized C and Assembler
implementations of OpenSSL.

WWW: http://senier.net/libsparkcrypto/