core: WebRTC frames encryption (#1942)

* core: WebRTC frames encryption

* test

tests/Test.hs

@@ -8,6 +8,7 @@ import ProtocolTests
 import SchemaDump
 import Test.Hspec
 import UnliftIO.Temporary (withTempDirectory)
+import WebRTCTests
 
 main :: IO ()
 main = do
@@ -15,6 +16,7 @@ main = do
   withGlobalLogging logCfg . hspec $ do
     describe "SimpleX chat markdown" markdownTests
     describe "SimpleX chat protocol" protocolTests
+    describe "WebRTC encryption" webRTCTests
     describe "Schema dump" schemaDumpTest
     around testBracket $ do
       describe "Mobile API Tests" mobileTests

tests/WebRTCTests.hs

@@ -0,0 +1,18 @@
+module WebRTCTests where
+
+import Crypto.Random (getRandomBytes)
+import qualified Data.ByteString.Base64.URL as U
+import qualified Data.ByteString.Char8 as B
+import Simplex.Chat.Mobile.WebRTC
+import Test.Hspec
+
+webRTCTests :: Spec
+webRTCTests = describe "WebRTC crypto" $ do
+  it "encrypts and decrypts media" $ do
+    key <- U.encode <$> getRandomBytes 32
+    frame <- getRandomBytes 1000
+    let reservedSize = authTagSize + ivSize
+    frame' <- chatEncryptMedia key $ frame <> B.replicate reservedSize '\NUL'
+    B.length frame' `shouldBe` B.length frame + reservedSize
+    frame'' <- chatDecryptMedia key frame'
+    frame'' `shouldBe` frame <> B.replicate reservedSize '\NUL'