deserialization of signatures and identifiers

codexvalidator/basics.nim

@@ -1,7 +1,9 @@
 import std/sequtils
 import pkg/stint
 import pkg/questionable
+import pkg/questionable/results
 
 export sequtils
 export stint
 export questionable
+export results

codexvalidator/signatures.nim

@@ -2,8 +2,10 @@ import ./signatures/identity
 import ./signatures/signing
 import ./signatures/signed
 import ./signatures/serialization
+import ./signatures/deserialization
 
 export identity
 export signing
 export signed
 export serialization
+export deserialization

codexvalidator/signatures/deserialization.nim

@@ -0,0 +1,18 @@
+import pkg/blscurve
+import ../basics
+import ./identity
+import ./signing
+
+func fromBytes*(_: type Identifier, bytes: openArray[byte]): ?!Identifier =
+  var identifier: Identifier
+  if blscurve.fromBytes(identifier, bytes):
+    success identifier
+  else:
+    failure "invalid identifier"
+
+func fromBytes*(_: type Signature, bytes: openArray[byte]): ?!Signature =
+  var signature: Signature
+  if blscurve.fromBytes(signature, bytes):
+    success signature
+  else:
+    failure "invalid signature"

tests/codexvalidator/basics.nim

@@ -1,11 +1,15 @@
 import std/unittest
 import std/sequtils
-import pkg/stint
-
 export unittest
 export sequtils
+
+import pkg/stint
 export stint
 
-import ./examples
+import pkg/questionable
+import pkg/questionable/results
+export questionable
+export results
 
+import ./examples
 export examples

tests/codexvalidator/examples.nim

@@ -74,6 +74,12 @@ proc example*(_: type Transaction): Transaction =
 proc example*(_: type Identity): Identity =
   Identity.random(result)
 
+proc example*(_: type Identifier): Identifier =
+  Identity.example.identifier
+
+proc example*(_: type Signature): Signature =
+  Identity.example.sign(seq[byte].example)
+
 proc example*(_: type CommitteeMember): CommitteeMember =
   CommitteeMember(uint32.example.int)
 

tests/codexvalidator/testSignatures.nim

@@ -49,3 +49,25 @@ suite "Signature scheme":
     let hash = Hash.example
     let signature = identity.sign(hash)
     check signature.verify(identity.identifier, hash)
+
+  test "identifier can be serialized and deserialized":
+    let identifier = Identifier.example
+    let serialized = identifier.toBytes()
+    check Identifier.fromBytes(serialized) == success identifier
+
+  test "identifier deserialization fails when wrong number of bytes":
+    let identifier = Identifier.example
+    let serialized = identifier.toBytes()
+    let invalid = serialized & 42'u8
+    check isFailure Identifier.fromBytes(invalid)
+
+  test "signature can be serialized and deserialized":
+    let signature = Signature.example
+    let serialized = signature.toBytes()
+    check Signature.fromBytes(serialized) == success signature
+
+  test "signature deserialization fails when wrong number of bytes":
+    let signature = Signature.example
+    let serialized = signature.toBytes()
+    let invalid = serialized & 42'u8
+    check isFailure Signature.fromBytes(invalid)