wip: modeling secio

libp2p/protocols/secure/secio.nim

@@ -7,26 +7,85 @@
 ## This file may not be copied, modified, or distributed except according to
 ## those terms.
 
-import chronos
-import secure,
-       ../../connection
+import chronos, chronicles, nimcrypto/sysrand
+import secure, ../../connection, ../../crypto/crypto
 
-const SecioCodec* = "/plaintext/1.0.0"
+logScope:
+  topic = "secio"
+
+const
+  SecioCodec* = "/secio/1.0.0"
+  SecioMaxMessageSize = 8 * 1024 * 1024 ## 8mb
+  SecioNonceSize = 16
+  SecioExchanges = "P-256,P-384,P-521"
+  SecioCiphers = "AES-256,AES-128"
+  SecioHashes = "SHA-256,SHA-512"
 
 type
   Secio = ref object of Secure
+    localPublicKey: PublicKey
 
-proc encodeProposalMsg*() = discard
-proc decodeProposalMsg*() = discard
+proc transactMessage(conn: Connection,
+                     msg: seq[byte]): Future[seq[byte]] {.async.} =
+  var buf = newSeq[byte](4)
+  try:
+    debug "Sending proposal", message = toHex(msg)
+    await conn.write(msg)
+    await conn.readExactly(addr buf[0], 4)
+    let length = (int(buf[0]) shl 24) or (int(buf[1]) shl 16) or
+                 (int(buf[2]) shl 8) or (int(buf[3]))
+    debug "Recieved message header", header = toHex(buf), length = length
+    if length <= SecioMaxMessageSize:
+      buf.setLen(length)
+      await conn.readExactly(addr buf[0], length)
+      debug "Received message body", conn = conn, length = length
+      result = buf
+    else:
+      debug "Received size of message exceed limits", conn = conn,
+                                                      length = length
+  except AsyncStreamIncompleteError:
+    debug "Connection dropped while reading", conn = conn
+  except AsyncStreamReadError:
+    debug "Error reading from connection", conn = conn
+  except AsyncStreamWriteError:
+    debug "Could not write to connection", conn = conn
+
+proc handshake*(p: Secio, conn: Connection) {.async.} =
+  var nonce: array[SecioNonceSize, byte]
+  var pk = p.localPublicKey.getBytes()
+  echo toHex(pk)
+  if randomBytes(nonce) != SecioNonceSize:
+    raise newException(CatchableError, "Could not generate random data")
+  
+  debug "Local proposal", schemes = SecioExchanges, ciphers = SecioCiphers,
+                          hashes = SecioHashes, nonce = toHex(nonce),
+                          pubkey = toHex(pk)
+  
+  echo "local proposal"
+
+  var answer = await transactMessage(conn,
+    createProposal(nonce, pk, SecioExchanges, SecioCiphers, SecioHashes)
+  )
+
+  echo toHex(answer)
+
+  if len(answer) == 0:
+    debug "Proposal exchange failed", conn = conn
+    return
 
 method init(p: Secio) {.gcsafe.} =
   proc handle(conn: Connection, proto: string) {.async, gcsafe.} = 
-    discard
+    echo "HERE"
 
   p.codec = SecioCodec
   p.handler = handle
 
-proc newSecio*(): Secio =
+method secure*(p: Secio, conn: Connection): Future[Connection] {.async, gcsafe.} =
+  echo "handshaking"
+  await p.handshake(conn)
+
+proc newSecio*(localPublicKey: PublicKey): Secio =
   new result
+  result.localPublicKey = localPublicKey
   result.init()
 

libp2p/protocols/secure/secure.nim

@@ -15,7 +15,6 @@ const PlainTextCodec* = "/plaintext/1.0.0"
 
 type
   Secure* = ref object of LPProtocol # base type for secure managers
-
   PlainText* = ref object of Secure
 
 method init(p: PlainText) {.gcsafe.} =
@@ -26,7 +25,7 @@ method init(p: PlainText) {.gcsafe.} =
   p.codec = PlainTextCodec
   p.handler = handle
 
-method secure(p: Secure, conn: Connection): Future[Connection] 
+method secure*(p: Secure, conn: Connection): Future[Connection]
   {.base, async, gcsafe.} = discard
 
 proc newPlainText*(): PlainText =