README.md (3219B)
1 # bech32 2 3 [](https://hackage.haskell.org/package/ppad-bech32) 4  5 [](https://docs.ppad.tech/bech32) 6 7 A pure Haskell implementation of bech32m and bech32 encoding/decoding on 8 strict ByteStrings, as specified by [BIP350][bi350] and [BIP173][bi173]. 9 10 ## Usage 11 12 A sample GHCi session: 13 14 ``` 15 > :set -XOverloadedStrings 16 > 17 > -- import qualified 18 > import qualified Data.ByteString.Bech32m as Bech32m 19 > 20 > -- create a bech32m-encoded string using a human-readable part (HRP) 21 > -- and some input 22 > let Just bech32m = Bech32m.encode "bc" "a standard word8 bytestring" 23 > bech32m 24 "bc1vys8xarpdejxzunyypmk7uny8qsxy7t5v4ehgunfdenswyuz0e" 25 > 26 > -- verify that a bech32m string has a valid checksum 27 > Bech32m.verify bech32 28 True 29 > 30 > -- tweaked stuff will obviously fail to verify (s/m/w below) 31 > Bech32m.verify "bc1vys8xarpdejxzunyypwk7uny8qsxy7t5v4ehgunfdenswyuz0e" 32 False 33 > 34 > -- decode bech32m-encoded input 35 > Bech32m.decode bech32m 36 Just ("bc","a standard word8 bytestring") 37 ``` 38 39 ## Documentation 40 41 Haddocks (API documentation, etc.) are hosted at 42 [docs.ppad.tech/bech32](https://docs.ppad.tech/bech32). 43 44 ## Performance 45 46 The aim is best-in-class performance for pure Haskell code. 47 48 Current benchmark figures on a M4 Silicon MacBook Air look like (use 49 `cabal bench` to run the benchmark suite): 50 51 ``` 52 benchmarking benchmarks/ppad-bech32/bech32 decode/120b 53 time 501.7 ns (497.7 ns .. 505.6 ns) 54 0.999 R² (0.999 R² .. 1.000 R²) 55 mean 494.4 ns (491.6 ns .. 498.0 ns) 56 std dev 10.81 ns (8.895 ns .. 12.98 ns) 57 variance introduced by outliers: 28% (moderately inflated) 58 59 benchmarking benchmarks/ppad-bech32/bech32 decode/120b 60 time 501.7 ns (497.7 ns .. 505.6 ns) 61 0.999 R² (0.999 R² .. 1.000 R²) 62 mean 494.4 ns (491.6 ns .. 498.0 ns) 63 std dev 10.81 ns (8.895 ns .. 12.98 ns) 64 variance introduced by outliers: 28% (moderately inflated) 65 ``` 66 67 You should compile with the 'llvm' flag for maximum performance. 68 69 ## Security 70 71 This library aims at the maximum security achievable in a 72 garbage-collected language under an optimizing compiler such as GHC, in 73 which strict constant-timeness can be challenging to achieve. 74 75 If you discover any vulnerabilities, please disclose them via 76 security@ppad.tech. 77 78 ## Development 79 80 You'll require [Nix][nixos] with [flake][flake] support enabled. Enter a 81 development shell with: 82 83 ``` 84 $ nix develop 85 ``` 86 87 Then do e.g.: 88 89 ``` 90 $ cabal repl ppad-bech32 91 ``` 92 93 to get a REPL for the main library. 94 95 ## Attribution 96 97 The base32 implementation used internally is more or less a pure 98 translation of the [base32][bas32] package on Hackage. 99 100 [nixos]: https://nixos.org/ 101 [flake]: https://nixos.org/manual/nix/unstable/command-ref/new-cli/nix3-flake.html 102 [bi173]: https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki 103 [bi350]: https://github.com/bitcoin/bips/blob/master/bip-0350.mediawiki 104 [bas32]: https://hackage.haskell.org/package/base32