Add crypto backend using various reference librariesHEADmaster

1 files changed, 19 insertions, 0 deletions

diff --git a/src/crypto/reflibs/Crypto/Random/Entropy.hs b/src/crypto/reflibs/Crypto/Random/Entropy.hs
new file mode 100644
index 0000000..d0685e4
--- /dev/null
+++ b/src/crypto/reflibs/Crypto/Random/Entropy.hs
@@ -0,0 +1,19 @@
+module Crypto.Random.Entropy (
+    getEntropy,
+) where
+
+import Foreign.C.Error
+import Foreign.C.Types
+import Foreign.Marshal.Alloc
+import Foreign.Ptr
+
+import Data.ByteString (ByteString)
+import Data.ByteString.Unsafe
+
+getEntropy :: Int -> IO ByteString
+getEntropy n = do
+    bytes <- mallocBytes n
+    throwErrnoIfMinus1_ "getentropy" $ c_getentropy bytes (fromIntegral n)
+    unsafePackMallocCStringLen ( bytes, n )
+
+foreign import ccall "unistd.h getentropy" c_getentropy :: Ptr CChar -> CSize -> IO CInt