Correct parsing of the `weak-subjectivity-checkpoint` parameter (#3765)

beacon_chain/conf.nim

@@ -958,11 +958,14 @@ func completeCmdArg*(T: type PubKey0x, input: string): seq[string] =
 func parseCmdArg*(T: type Checkpoint, input: string): T
                  {.raises: [ValueError, Defect].} =
   let sepIdx = find(input, ':')
-  if sepIdx == -1:
+  if sepIdx == -1 or sepIdx == input.len - 1:
     raise newException(ValueError,
       "The weak subjectivity checkpoint must be provided in the `block_root:epoch_number` format")
-  T(root: Eth2Digest.fromHex(input[0 ..< sepIdx]),
-    epoch: parseBiggestUInt(input[sepIdx .. ^1]).Epoch)
+
+  var root: Eth2Digest
+  hexToByteArrayStrict(input.toOpenArray(0, sepIdx - 1), root.data)
+
+  T(root: root, epoch: parseBiggestUInt(input[sepIdx + 1 .. ^1]).Epoch)
 
 func completeCmdArg*(T: type Checkpoint, input: string): seq[string] =
   return @[]

tests/all_tests.nim

@@ -19,6 +19,7 @@ import # Unit test
   ./test_block_dag,
   ./test_block_processor,
   ./test_block_quarantine,
+  ./test_conf,
   ./test_datatypes,
   ./test_discovery,
   ./test_engine_authentication,

tests/test_conf.nim

@@ -0,0 +1,60 @@
+import
+  unittest2,
+  ../beacon_chain/conf
+
+template reject(val: string) =
+  expect CatchableError:
+    echo Checkpoint.parseCmdArg(val)
+
+suite "Configuration parsing":
+  suite "weak-subjectivity-checkpoint":
+    test "Correct values":
+      let
+        c1 = Checkpoint.parseCmdArg("0x3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb5:31714")
+        c2 = Checkpoint.parseCmdArg("3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb5:31714")
+     
+      check:
+        c1.epoch == 31714
+        c1.root == Eth2Digest.fromHex("3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb5")
+        c1 == c2
+
+      #[
+      let
+        c3 = Checkpoint.parseCmdArg("3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb5:0")
+        c4 = Checkpoint.parseCmdArg("3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb5:1")
+
+      check:
+        c3.epoch == 0
+        c4.epoch == 1
+      ]#
+
+    test "missing separator":
+      reject ""
+      reject "3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb5"
+      reject "0x3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb5"
+      reject "3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb531714"
+
+    test "missing root":
+      reject ":31714"
+
+    test "shorter root":
+      reject "3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfe:31714"
+      reject "3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb:31714"
+
+    test "longer root":
+      reject "3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb50:31714"
+      reject "3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb500:31714"
+      
+    test "invalid characters in root":
+      reject "1x3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb5:31714"
+      reject "3g1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb5:31714"
+
+    test "missing epoch":
+      reject "3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb500:"
+      
+    test "non-number epoch":
+      reject "3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb500:123c"
+      reject "3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb500:а"
+
+    test "negative epoch":
+      reject "3c1e98bf132530c669723f58aa3d395be0d0bfaa653152eecb04605e203bfeb500:-1000"

vendor/nim-stew

@@ -1 +1 @@
-Subproject commit 419903c9a31ab253cf5cf19f24d9a912dc4b5154
+Subproject commit f75c0a273aa34880ae7ac99e7e0c5d16b26ef166