X-Git-Url: http://git.euphorik.ch/?a=blobdiff_plain;f=labo2-fsharp%2FCryptoFile%2FCrypto.fs;h=560cd1316378b366fe731f3acbf07a55d2dee2b2;hb=2fcf3ed38874e9aa6d2ccd6b9917bd3113d76aee;hp=836d636af67b37e72fabf38ed5984659b518b75a;hpb=137157b6dbd5efb99b486a30da6e10b0a175f530;p=crypto_lab2.git

diff --git a/labo2-fsharp/CryptoFile/Crypto.fs b/labo2-fsharp/CryptoFile/Crypto.fs
index 836d636..560cd13 100644
--- a/labo2-fsharp/CryptoFile/Crypto.fs
+++ b/labo2-fsharp/CryptoFile/Crypto.fs
@@ -1,11 +1,11 @@
 namespace CryptoFile
 
+open System
+open System.IO
+open System.Security.Cryptography
+
 // Some cryptography primitives specific to CryptoFile.
 module internal Crypto =
-    open System
-    open System.IO
-    open System.Security.Cryptography
-
     type Data = byte[]
 
     let rsaKeySize = 2048
@@ -62,7 +62,7 @@ module internal Crypto =
     /// Returns an encrypted output stream.
     let encryptAES (key: byte[]) (iv: byte[]) (outputStream: Stream) : CryptoStream =
         assert (key.Length = 32 && iv.Length = 16)
-        use aes = new AesManaged ()
+        use aes = new AesCryptoServiceProvider () // Default mode is CBC.
         aes.KeySize <- 256
         let encryptor = aes.CreateEncryptor (key, iv)
         new CryptoStream (outputStream, encryptor, CryptoStreamMode.Write)
@@ -70,24 +70,18 @@ module internal Crypto =
     /// Returns a decrypted input stream.
     let decryptAES (key: byte[]) (iv: byte[]) (inputStream: Stream) : CryptoStream =
         assert (key.Length = 32 && iv.Length = 16)
-        use aes = new AesManaged ()
+        use aes = new AesCryptoServiceProvider ()
         aes.KeySize <- 256
         let decryptor = aes.CreateDecryptor (key, iv)
         new CryptoStream (inputStream, decryptor, CryptoStreamMode.Read)
 
+    // Create a stream to compute the HMAC-SHA256 against all data being written.
     let HMACStream (key: byte[]) (outputStream: Stream) : Stream * HMACSHA256 = 
         assert (key.Length = 32)
         let hmac = new HMACSHA256 (key)
         new CryptoStream (outputStream, hmac, CryptoStreamMode.Write) :> Stream, hmac
 
-    (*type HMACStream (buffer: byte[], output: Stream) =
-        inherit Stream () 
-        override this.CanRead with get () = false
-        override this.CanSeek with get () = false
-        override this.CanWrite with get () = true
-        override this.Length with get () = raise <| new NotSupportedException ()
-        override this.Position with get () = raise <| new NotSupportedException ()
-                               and set _ = raise <| new NotSupportedException ()
-        override this.Flush () =
-            output.Flush ()
-        override this.Read (_: byte[], _: int, _: int) = raise <| new NotSupportedException ()*)
\ No newline at end of file
+    let ComputeHMAC (key: byte[]) (inputStream: Stream) : byte[] =
+        assert (key.Length = 32)
+        let hmac = new HMACSHA256 (key)
+        hmac.ComputeHash inputStream
\ No newline at end of file