b8a00ee · typeable/entropy

git.iko.soy/typeable/entropy

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Fix (?) the windows build

b8a00eeThomas M. DuBuisson13 years ago

System/Entropy.hs+43−8

compare with main

unifiedsplit

@@ -41,12 +41,28 @@ import Data.ByteString.Internal as BI

41import Data.Int (Int32)

42import Data.Word (Word32, Word8)

43import Foreign.C.String (CString, withCString)

44−import Foreign.Ptr (Ptr, nullPtr)

44+import Foreign.C.Types

45+import Foreign.Ptr (Ptr, nullPtr, castPtr)

45import Foreign.Marshal.Alloc (alloca)

46import Foreign.Marshal.Alloc (alloca)

46import Foreign.Marshal.Utils (toBool)

47import Foreign.Marshal.Utils (toBool)

47import Foreign.Storable (peek)

48import Foreign.Storable (peek)

50+#ifdef arch_x86_64

51+foreign import ccall unsafe "cpu_has_rdrand"

52+ c_cpu_has_rdrand :: IO CInt

53+

54+foreign import ccall unsafe "get_rand_bytes"

55+ c_get_rand_bytes :: Ptr CUChar -> CSize -> IO CInt

56+

57+cpuHasRdRand :: IO Bool

58+cpuHasRdRand = (/= 0) `fmap` c_cpu_has_rdrand

59+#endif

60+

49−newtype CryptHandle = CH Word32

61+newtype CryptHandle

62+ = CH Word32

63+#ifdef arch_x86_64

64+ | UseRdRand

65+#endif

51-- Define the constants we need from WinCrypt.h

67-- Define the constants we need from WinCrypt.h

52msDefProv :: String

68msDefProv :: String

@@ -95,6 +111,11 @@ cryptReleaseCtx h = do

95-- on platforms without a secure RNG!

111-- on platforms without a secure RNG!

96getEntropy :: Int -> IO B.ByteString

112getEntropy :: Int -> IO B.ByteString

97getEntropy n = do

113getEntropy n = do

114+#ifdef arch_x86_64

115+ b <- cpuHasRdRand

116+ if b then hGetEntropy UseRdRand n

117+ else do

118+#endif

98 h <- cryptAcquireCtx

119 h <- cryptAcquireCtx

99 bs <- cryptGenRandom h n

120 bs <- cryptGenRandom h n

100 let !bs' = bs

121 let !bs' = bs

@@ -103,7 +124,13 @@ getEntropy n = do

103

124

104-- |Open a handle from which random data can be read

125-- |Open a handle from which random data can be read

105openHandle :: IO CryptHandle

126openHandle :: IO CryptHandle

127+openHandle = do

128+#ifdef arch_x86_64

129+ b <- cpuHasRdRand

130+ if b then return UseRdRand

131+ else do

132+#endif

106−openHandle = liftM CH cryptAcquireCtx

133+ liftM CH cryptAcquireCtx

107

134

108-- |Close the `CryptHandle`

135-- |Close the `CryptHandle`

109closeHandle (CH h) = cryptReleaseCtx h

136closeHandle (CH h) = cryptReleaseCtx h

@@ -111,6 +138,13 @@ closeHandle (CH h) = cryptReleaseCtx h

111-- |Read from `CryptHandle`

138-- |Read from `CryptHandle`

112hGetEntropy :: CryptHandle -> Int -> IO B.ByteString

139hGetEntropy :: CryptHandle -> Int -> IO B.ByteString

113hGetEntropy (CH h) = cryptGenRandom h

140hGetEntropy (CH h) = cryptGenRandom h

141+#ifdef arch_x86_64

142+hGetEntropy UseRdRand =

143+ B.create n $ \ptr -> do

144+ r <- c_get_rand_bytes (castPtr ptr) (fromIntegral n)

145+ when (r /= 0)

146+ (fail "RDRand failed to gather entropy")

147+#endif

114

148

115#else

149#else

116{- Not windows, assuming nix with a /dev/urandom -}

150{- Not windows, assuming nix with a /dev/urandom -}

@@ -122,7 +156,11 @@ source :: FilePath

122source = "/dev/urandom"

156source = "/dev/urandom"

123

157

124-- |Handle for manual resource mangement

158-- |Handle for manual resource mangement

125−data CryptHandle = CH Handle | UseRdRand

159+data CryptHandle

160+ = CH Handle

161+#ifdef arch_x86_64

162+ | UseRdRand

163+#endif

126

164

127-- |Open a `CryptHandle`

165-- |Open a `CryptHandle`

128openHandle :: IO CryptHandle

166openHandle :: IO CryptHandle

@@ -173,10 +211,7 @@ getEntropy :: Int -> IO B.ByteString

173getEntropy n = do

211getEntropy n = do

174#if arch_x86_64

212#if arch_x86_64

175 b <- cpuHasRdRand

213 b <- cpuHasRdRand

176− if b then B.create n $ \ptr -> do

214+ if b then hGetEntropy UseRdRand n

177− r <- c_get_rand_bytes (castPtr ptr) (fromIntegral n)

178− when (r /= 0)

179− (fail "RDRand failed to gather entropy")

180 else do

215 else do

181#endif

216#endif

182{- arch_x86 -}

217{- arch_x86 -}