integer-openssl

Implementation of the GHC.Integer type using the OpenSSL BIGNUM arbitrary size integer library contained in libcrypto.

Work in progress

This is currently in development and not yet ready for production. Integration with GHC is discussed here. If things work out, this would be a free BSD-licensed alternative to the LGPL-licensed integer-gmp - used by default in GHC - with performance significantly faster than integer-simple - a BSD-licensed Haskell-only integer library.

The test suite gives a rough estimate what currently works as each function is checked against the builtin library.

Recent benchmarks of small, 128bit and 4096bit integers multiplication and division indicate a 10-20% performance hit against integer-gmp but significant speedup compared to integer-simple:

• integer-openssl vs. integer-gmp
• integer-openssl vs. integer-simple

License

The source code for integer-openssl is released under the BSD-3-Clause License.

TODO and ideas

• [ ] Implement the portable GHC.Integer interface
• [ ] Test suite covering all functions
  • [ ] encodeDoubleInteger fails for newer LTS / GHC?
  • [ ] test gcdInteger
  • [ ] test lcmInteger
• [ ] 32bit support
  • [ ] implement and test int64ToInteger
  • [ ] implement and test word64ToInteger
  • [ ] implement and test integerToInt64
  • [ ] implement and test integerToWord64
• [ ] Add some more short cuts
• [ ] Look into strictness/lazyness
• [ ] Common Natural implementation with integer-gmp (as its the same small/big abstraction)
• [ ] DRY code with integer-gmp
  • [ ] Integer functions in base and only BigNat/BigNum in libs?
  • [ ] Re-use BigNat/BigNum and exchange/use FFI/C parts if possible
• [ ] Rename library and flags to integer-crypto?
• [ ] Statically link libcrypto into GHC?