diff --git a/codex.nim b/codex.nim
index 36ae7990..528e48d2 100644
--- a/codex.nim
+++ b/codex.nim
@@ -91,7 +91,7 @@ when isMainModule:
         waitFor server.stop()
         notice "Stopped Codex"
 
-      c_signal(SIGTERM, SIGTERMHandler)
+      c_signal(ansi_c.SIGTERM, SIGTERMHandler)
 
     waitFor server.start()
     notice "Exited codex"
diff --git a/codex/blockexchange/network/networkpeer.nim b/codex/blockexchange/network/networkpeer.nim
index c9b8405e..cef58bc5 100644
--- a/codex/blockexchange/network/networkpeer.nim
+++ b/codex/blockexchange/network/networkpeer.nim
@@ -7,6 +7,9 @@
 ## This file may not be copied, modified, or distributed except according to
 ## those terms.
 
+import pkg/upraises
+push: {.upraises: [].}
+
 import pkg/chronos
 import pkg/chronicles
 import pkg/libp2p
@@ -21,6 +24,8 @@ const
   MaxMessageSize = 100 * 1 shl 20 # manifest files can be big
 
 type
+  ConnProvider* = proc(): Future[Connection] {.gcsafe, closure.}
+
   RPCHandler* = proc(peer: NetworkPeer, msg: Message): Future[void] {.gcsafe.}
 
   NetworkPeer* = ref object of RootObj
diff --git a/codex/rng.nim b/codex/rng.nim
index b1f6266d..19452cd4 100644
--- a/codex/rng.nim
+++ b/codex/rng.nim
@@ -12,11 +12,11 @@ import pkg/upraises
 push: {.upraises: [].}
 
 import pkg/libp2p/crypto/crypto
-import pkg/bearssl
+import pkg/bearssl/rand
 
 type
   RngSampleError = object of CatchableError
-  Rng* = ref BrHmacDrbgContext
+  Rng* = ref HmacDrbgContext
 
 var rng {.threadvar.}: Rng
 
@@ -25,16 +25,15 @@ proc instance*(t: type Rng): Rng =
     rng = newRng()
   rng
 
-# Random helpers: similar as in stdlib, but with BrHmacDrbgContext rng
+# Random helpers: similar as in stdlib, but with HmacDrbgContext rng
 # TODO: Move these somewhere else?
 const randMax = 18_446_744_073_709_551_615'u64
 
 proc rand*(rng: Rng, max: Natural): int =
   if max == 0: return 0
 
-  var x: uint64
   while true:
-    brHmacDrbgGenerate(addr rng[], addr x, csize_t(sizeof(x)))
+    let x = rng[].generate(uint64)
     if x < randMax - (randMax mod (uint64(max) + 1'u64)): # against modulo bias
       return int(x mod (uint64(max) + 1'u64))
 
diff --git a/codex/streams/asyncstreamwrapper.nim b/codex/streams/asyncstreamwrapper.nim
index 81406bc3..a0829b7b 100644
--- a/codex/streams/asyncstreamwrapper.nim
+++ b/codex/streams/asyncstreamwrapper.nim
@@ -7,7 +7,8 @@
 ## This file may not be copied, modified, or distributed except according to
 ## those terms.
 
-{.push raises: [Defect].}
+import pkg/upraises
+push: {.upraises: [].}
 
 import pkg/chronos
 import pkg/chronicles
diff --git a/tests/codex/blockexchange/testnetwork.nim b/tests/codex/blockexchange/testnetwork.nim
index 8eda6a93..9f3c399e 100644
--- a/tests/codex/blockexchange/testnetwork.nim
+++ b/tests/codex/blockexchange/testnetwork.nim
@@ -158,9 +158,6 @@ suite "Network - Senders":
     done = newFuture[void]()
     switch1 = newStandardSwitch()
     switch2 = newStandardSwitch()
-    await switch1.start()
-    await switch2.start()
-
     network1 = BlockExcNetwork.new(
       switch = switch1)
     switch1.mount(network1)
@@ -169,6 +166,9 @@ suite "Network - Senders":
       switch = switch2)
     switch2.mount(network2)
 
+    await switch1.start()
+    await switch2.start()
+
     await switch1.connect(
       switch2.peerInfo.peerId,
       switch2.peerInfo.addrs)
@@ -271,8 +271,6 @@ suite "Network - Test Limits":
     done = newFuture[void]()
     switch1 = newStandardSwitch()
     switch2 = newStandardSwitch()
-    await switch1.start()
-    await switch2.start()
 
     network1 = BlockExcNetwork.new(
       switch = switch1,
@@ -283,6 +281,9 @@ suite "Network - Test Limits":
       switch = switch2)
     switch2.mount(network2)
 
+    await switch1.start()
+    await switch2.start()
+
     await switch1.connect(
       switch2.peerInfo.peerId,
       switch2.peerInfo.addrs)
diff --git a/tests/codex/helpers.nim b/tests/codex/helpers.nim
index 475bf7a1..6d431870 100644
--- a/tests/codex/helpers.nim
+++ b/tests/codex/helpers.nim
@@ -37,12 +37,11 @@ proc corruptBlocks*(
   manifest: Manifest,
   blks, bytes: int): Future[seq[int]] {.async.} =
   var pos: seq[int]
-  while true:
-    if pos.len >= blks:
-      break
 
-    var i = -1
-    if (i = Rng.instance.rand(manifest.len - 1); pos.find(i) >= 0):
+  doAssert blks < manifest.len
+  while pos.len < blks:
+    let i = Rng.instance.rand(manifest.len - 1)
+    if pos.find(i) >= 0:
       continue
 
     pos.add(i)
@@ -50,15 +49,12 @@ proc corruptBlocks*(
       blk = (await store.getBlock(manifest[i])).tryGet()
       bytePos: seq[int]
 
-    while true:
-      if bytePos.len > bytes:
-        break
-
-      var ii = -1
-      if (ii = Rng.instance.rand(blk.data.len - 1); bytePos.find(ii) >= 0):
+    doAssert bytes < blk.data.len
+    while bytePos.len <= bytes:
+      let ii = Rng.instance.rand(blk.data.len - 1)
+      if bytePos.find(ii) >= 0:
         continue
 
       bytePos.add(ii)
       blk.data[ii] = byte 0
-
   return pos