module Distribution.Nixpkgs.Hashes ( printSHA256, packHex ) where
import Control.Exception ( assert )
import Data.Bits
import Data.ByteString ( ByteString )
import qualified Data.ByteString as BS
import qualified Data.ByteString.Char8 as BSC
import Data.Char
import Data.Word
base32chars :: ByteString
base32chars :: ByteString
base32chars = String -> ByteString
BSC.pack String
"0123456789abcdfghijklmnpqrsvwxyz";
printSHA256 :: ByteString -> String
printSHA256 :: ByteString -> String
printSHA256 ByteString
buf = Bool -> String -> String
forall a. (?callStack::CallStack) => Bool -> a -> a
assert (ByteString -> Int
BS.length ByteString
buf Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
32) (String -> String) -> String -> String
forall a b. (a -> b) -> a -> b
$
(Int -> Char) -> [Int] -> String
forall a b. (a -> b) -> [a] -> [b]
map (ByteString -> Int -> Char
BSC.index ByteString
base32chars (Int -> Char) -> (Int -> Int) -> Int -> Char
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Word8 -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Word8 -> Int) -> (Int -> Word8) -> Int -> Int
forall b c a. (b -> c) -> (a -> b) -> a -> c
. ByteString -> Int -> Word8
getQuintet ByteString
buf) [Int
51,Int
50..Int
0]
getQuintet :: ByteString -> Int -> Word8
getQuintet :: ByteString -> Int -> Word8
getQuintet ByteString
buf Int
n = (Word8
c1 Word8 -> Word8 -> Word8
forall a. Bits a => a -> a -> a
.|. Word8
c2) Word8 -> Word8 -> Word8
forall a. Bits a => a -> a -> a
.&. Word8
0x1f
where
b :: Int
b = Int
n Int -> Int -> Int
forall a. Num a => a -> a -> a
* Int
5
(Int
i,Int
j) = Int
b Int -> Int -> (Int, Int)
forall a. Integral a => a -> a -> (a, a)
`divMod` Int
8
c1 :: Word8
c1 = ByteString -> Int -> Word8
BS.index ByteString
buf Int
i Word8 -> Int -> Word8
forall a. Bits a => a -> Int -> a
`shiftR` Int
j
c2 :: Word8
c2 = if Int
i Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
>= Int
31 then Word8
0 else ByteString -> Int -> Word8
BS.index ByteString
buf (Int
iInt -> Int -> Int
forall a. Num a => a -> a -> a
+Int
1) Word8 -> Int -> Word8
forall a. Bits a => a -> Int -> a
`shiftL` (Int
8Int -> Int -> Int
forall a. Num a => a -> a -> a
-Int
j)
packHex :: String -> ByteString
packHex :: String -> ByteString
packHex = [Word8] -> ByteString
BS.pack ([Word8] -> ByteString)
-> (String -> [Word8]) -> String -> ByteString
forall b c a. (b -> c) -> (a -> b) -> a -> c
. String -> [Word8]
hex2bin
hex2bin :: String -> [Word8]
hex2bin :: String -> [Word8]
hex2bin String
input = String -> [Word8]
f (String -> [Word8]) -> String -> [Word8]
forall a b. (a -> b) -> a -> b
$ (if Int -> Bool
forall a. Integral a => a -> Bool
even (String -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length String
input) then String -> String
forall a. a -> a
id else (Char
'0'Char -> String -> String
forall a. a -> [a] -> [a]
:)) String
input
where
f :: String -> [Word8]
f :: String -> [Word8]
f [] = []
f [Char
x] = [Char -> Word8
digit Char
x]
f (Char
x1:Char
x2:String
xs) = ((Char -> Word8
digit Char
x1 Word8 -> Int -> Word8
forall a. Bits a => a -> Int -> a
`shiftL` Int
4) Word8 -> Word8 -> Word8
forall a. Bits a => a -> a -> a
.|. Char -> Word8
digit Char
x2) Word8 -> [Word8] -> [Word8]
forall a. a -> [a] -> [a]
: String -> [Word8]
f String
xs
digit :: Char -> Word8
digit :: Char -> Word8
digit = Int -> Word8
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Int -> Word8) -> (Char -> Int) -> Char -> Word8
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Char -> Int
digitToInt