feat: dtls connection using mbedtls (#10)

* feat: dtls connection using mbedtls

* refactor: change according to the stun protocol rework

* chore: rename init proc into new

* docs: adds object field comments

* chore: split dtls.nim into two files & renaming

* chore: remove useless code

* chore: remove TODOs as they were addressed with a Stun refactorization

* fix: oversight on dtls.new

* feat: add dtls test

* chore: added license & used pragma on testdtls

* fix: remove usage of deprecated TrackerCounter

* fix: trackers counter

* fix:
- add windows linking library
- make stun stop asynchronous (causing issue on macos)
- store private key and certificate

* chore: renaming test

* docs: update DtlsConn comment

* fix: remove code duplicate

* chore: update comment

* chore: remove duplication mbedtls initialization code in accept/connect and un-expose mbedtls context

* feat: add exception management to dtls_transport

* fix: check address family before handshake

* fix: exhaustive case

* fix: do not create dtlsConn if the address family is not IP

* chore: remove entropy from MbedTLSCtx

* chore: remove asyncspawn of cleanupdtlsconn

* chore: ctx is no longer public

* test: add a test with more than 2 nodes

* chore: started is now useful

* chore: update Dtls.stop

* chore: removed unecessary todos

* docs: add comments on DtlsConn.read and getters

* feat: add tracker for dtls connection and transport

* chore: privatize local and remote certificate

* style: use nph

* fix: remove laddr from dtls_conn (not used)

* style: sort imports

* chore: clean Dtls.stop

* fix: remote address is no longer exposed

* fix: raddr change oversight

* chore: change `verify` name

* chore: changed `sendFuture: Future[void]` into `dataToSend: seq[byte]`

* chore: avoid sequence copy

* chore: change assert message

---------

Co-authored-by: diegomrsantos <[email protected]>

tests/runalltests.nim

@@ -10,3 +10,4 @@
 {.used.}
 
 import teststun
+import testdtls

tests/testdtls.nim

@@ -0,0 +1,83 @@
+# Nim-WebRTC
+# Copyright (c) 2024 Status Research & Development GmbH
+# Licensed under either of
+#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
+#  * MIT license ([LICENSE-MIT](LICENSE-MIT))
+# at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+{.used.}
+
+import chronos
+import ../webrtc/udp_transport
+import ../webrtc/stun/stun_transport
+import ../webrtc/dtls/dtls_transport
+import ../webrtc/dtls/dtls_connection
+import ./asyncunit
+
+suite "DTLS":
+  teardown:
+    checkLeaks()
+
+  asyncTest "Two DTLS nodes connecting to each other, then sending/receiving data":
+    let
+      localAddr1 = initTAddress("127.0.0.1:4444")
+      localAddr2 = initTAddress("127.0.0.1:5555")
+      udp1 = UdpTransport.new(localAddr1)
+      udp2 = UdpTransport.new(localAddr2)
+      stun1 = Stun.new(udp1)
+      stun2 = Stun.new(udp2)
+      dtls1 = Dtls.new(stun1)
+      dtls2 = Dtls.new(stun2)
+      conn1Fut = dtls1.accept()
+      conn2 = await dtls2.connect(localAddr1)
+      conn1 = await conn1Fut
+
+    await conn1.write(@[1'u8, 2, 3, 4])
+    let seq1 = await conn2.read()
+    check seq1 == @[1'u8, 2, 3, 4]
+
+    await conn2.write(@[5'u8, 6, 7, 8])
+    let seq2 = await conn1.read()
+    check seq2 == @[5'u8, 6, 7, 8]
+    await allFutures(conn1.close(), conn2.close())
+    await allFutures(dtls1.stop(), dtls2.stop())
+    await allFutures(stun1.stop(), stun2.stop())
+    await allFutures(udp1.close(), udp2.close())
+
+  asyncTest "Two DTLS nodes connecting to the same DTLS server, sending/receiving data":
+    let
+      localAddr1 = initTAddress("127.0.0.1:4444")
+      localAddr2 = initTAddress("127.0.0.1:5555")
+      localAddr3 = initTAddress("127.0.0.1:6666")
+      udp1 = UdpTransport.new(localAddr1)
+      udp2 = UdpTransport.new(localAddr2)
+      udp3 = UdpTransport.new(localAddr3)
+      stun1 = Stun.new(udp1)
+      stun2 = Stun.new(udp2)
+      stun3 = Stun.new(udp3)
+      dtls1 = Dtls.new(stun1)
+      dtls2 = Dtls.new(stun2)
+      dtls3 = Dtls.new(stun3)
+      servConn1Fut = dtls1.accept()
+      servConn2Fut = dtls1.accept()
+      clientConn1 = await dtls2.connect(localAddr1)
+      clientConn2 = await dtls3.connect(localAddr1)
+      servConn1 = await servConn1Fut
+      servConn2 = await servConn2Fut
+
+    await servConn1.write(@[1'u8, 2, 3, 4])
+    await servConn2.write(@[5'u8, 6, 7, 8])
+    await clientConn1.write(@[9'u8, 10, 11, 12])
+    await clientConn2.write(@[13'u8, 14, 15, 16])
+    check:
+      (await clientConn1.read()) == @[1'u8, 2, 3, 4]
+      (await clientConn2.read()) == @[5'u8, 6, 7, 8]
+      (await servConn1.read()) == @[9'u8, 10, 11, 12]
+      (await servConn2.read()) == @[13'u8, 14, 15, 16]
+    await allFutures(servConn1.close(), servConn2.close())
+    await allFutures(clientConn1.close(), clientConn2.close())
+    await allFutures(dtls1.stop(), dtls2.stop(), dtls3.stop())
+    await allFutures(stun1.stop(), stun2.stop(), stun3.stop())
+    await allFutures(udp1.close(), udp2.close(), udp3.close())

tests/teststun.nim

@@ -55,7 +55,7 @@ suite "Stun message encoding/decoding":
       decoded == msg
       messageIntegrity.attributeType == AttrMessageIntegrity.uint16
       fingerprint.attributeType == AttrFingerprint.uint16
-    conn.close()
+    await conn.close()
     await udp.close()
 
   asyncTest "Get BindingResponse from BindingRequest + encode & decode":
@@ -82,7 +82,7 @@ suite "Stun message encoding/decoding":
       bindingResponse == decoded
       messageIntegrity.attributeType == AttrMessageIntegrity.uint16
       fingerprint.attributeType == AttrFingerprint.uint16
-    conn.close()
+    await conn.close()
     await udp.close()
 
 suite "Stun checkForError":
@@ -114,7 +114,7 @@ suite "Stun checkForError":
 
     check:
       errorMissUsername.getAttribute(ErrorCode).get().getErrorCode() == ECBadRequest
-    conn.close()
+    await conn.close()
     await udp.close()
 
   asyncTest "checkForError: UsernameChecker returns false":
@@ -136,5 +136,5 @@ suite "Stun checkForError":
 
     check:
       error.getAttribute(ErrorCode).get().getErrorCode() == ECUnauthorized
-    conn.close()
+    await conn.close()
     await udp.close()

webrtc.nimble

@@ -17,12 +17,15 @@ let lang = getEnv("NIMLANG", "c") # Which backend (c/cpp/js)
 let flags = getEnv("NIMFLAGS", "") # Extra flags for the compiler
 let verbose = getEnv("V", "") notin ["", "0"]
 
-let cfg =
+var cfg =
   " --styleCheck:usages --styleCheck:error" &
   (if verbose: "" else: " --verbosity:0 --hints:off") &
   " --skipParentCfg --skipUserCfg -f" &
   " --threads:on --opt:speed"
 
+when defined(windows):
+  cfg = cfg & " --clib:ws2_32"
+
 import hashes
 
 proc runTest(filename: string) =