From 4e86fcb581c621de3ce7bb5f0c4d39303f0885b6 Mon Sep 17 00:00:00 2001
From: Mark Spanbroek <mark@spanbroek.net>
Date: Mon, 16 Dec 2024 17:27:17 +0100
Subject: [PATCH] deserialization of signatures and identifiers

---
 codexvalidator/basics.nim                     |  2 ++
 codexvalidator/signatures.nim                 |  2 ++
 codexvalidator/signatures/deserialization.nim | 18 +++++++++++++++
 tests/codexvalidator/basics.nim               | 10 ++++++---
 tests/codexvalidator/examples.nim             |  6 +++++
 tests/codexvalidator/testSignatures.nim       | 22 +++++++++++++++++++
 6 files changed, 57 insertions(+), 3 deletions(-)
 create mode 100644 codexvalidator/signatures/deserialization.nim

diff --git a/codexvalidator/basics.nim b/codexvalidator/basics.nim
index fe8adad..674299e 100644
--- a/codexvalidator/basics.nim
+++ b/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
diff --git a/codexvalidator/signatures.nim b/codexvalidator/signatures.nim
index c8d637f..53313bf 100644
--- a/codexvalidator/signatures.nim
+++ b/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
diff --git a/codexvalidator/signatures/deserialization.nim b/codexvalidator/signatures/deserialization.nim
new file mode 100644
index 0000000..07c82d4
--- /dev/null
+++ b/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"
diff --git a/tests/codexvalidator/basics.nim b/tests/codexvalidator/basics.nim
index f8e4c5b..38dcb09 100644
--- a/tests/codexvalidator/basics.nim
+++ b/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
diff --git a/tests/codexvalidator/examples.nim b/tests/codexvalidator/examples.nim
index 498bb1e..b5949f3 100644
--- a/tests/codexvalidator/examples.nim
+++ b/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)
 
diff --git a/tests/codexvalidator/testSignatures.nim b/tests/codexvalidator/testSignatures.nim
index 1489bfc..730df27 100644
--- a/tests/codexvalidator/testSignatures.nim
+++ b/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)