Remove tests of private fields + Hide privat fields for real

eth_keys.nimble

@@ -26,11 +26,6 @@ task test_cpp, "Run all tests - C++ only & libsecp256k1 backend":
   test "all_tests", "cpp"
 
 task test, "Run all tests - C and C++ & libsecp256k1 backend":
-  ## TODO: This only runs the C++ tests ...
-  # block:
-  #   test "all_tests"
-  # block:
-  #   test "all_tests", "cpp"
   exec "nimble test_c"
   exec "rm ./nimcache/*"
   exec "nimble test_cpp"

src/datatypes.nim

@@ -13,23 +13,52 @@ import ./private/conversion_bytes
 # See private field access issue: https://github.com/nim-lang/Nim/issues/7390
 type
   PublicKey* = object
-    Fraw_key*: array[64, byte]
+    Fraw_key: array[64, byte]
 
   PrivateKey* = object
-    Fraw_key*: array[32, byte]
+    Fraw_key: array[32, byte]
-    Fpublic_key*: PublicKey
+    Fpublic_key: PublicKey   # This is exported publicly through public_key
-
 
 type
-  Scalar256 = array[32, byte]
+  Scalar256 = distinct array[32, byte]
     # Secp256k1 makes the signature an opaque "implementation dependent".
     #
-    # Scalar256 is opaque/distinct too as in practice, they are uint256
+    # Scalar256 is opaque/distinct too as in practice it's uint256
-    # and by default we don't load any.
+    # and by default we don't load any uint256 library.
     # See implementation details in datatypes.md.
 
   Signature* {.packed.}= object
-    Fr*: Scalar256
+    Fr: Scalar256
-    Fs*: Scalar256
+    Fs: Scalar256
-    Fv*: range[0.byte .. 1.byte] # This should be 27..28 as per Ethereum but it's 0..1 in eth-keys ...
+    Fv: range[0.byte .. 1.byte] # This should be 27..28 as per Ethereum but it's 0..1 in eth-keys ...
 
+# Hide the private fields and generate accessors.
+# This is needed to:
+#   - Be able to not store the public_key in PrivateKey in the future and replace it by
+#     an on-the-fly computation
+#   - Signature: have different data representation
+
+template genAccessors(name: untyped, fieldType, objType: typedesc): untyped =
+  # Access
+  proc name*(obj: objType): fieldType {.noSideEffect, inline, noInit.} =
+    obj.`F name`
+
+  # Assignement
+  proc `name=`*(obj: var objType, value: fieldType) {.noSideEffect, inline.} =
+    obj.`F name` = value
+
+  # Mutable
+  proc `name`*(obj: var objType): var fieldType {.noSideEffect, inline.} =
+    obj.`F name`
+
+genAccessors(raw_key, array[64, byte], PublicKey)
+genAccessors(raw_key, array[32, byte], PrivateKey)
+genAccessors(public_key, PublicKey, PrivateKey)
+
+
+## If we hide the fields we need to provide a custom `==` proc
+## Because Nim `==` template will not be able to access the fields
+
+proc `==`*(x, y: Scalar256): bool {.noSideEffect, inline, borrow.}
+proc `==`*(x, y: PublicKey or PrivateKey or Signature): bool {.noSideEffect, inline.} =
+  system.`==`(x, y)

src/datatypes_interface.nim

@@ -31,8 +31,8 @@ else:
 # Initialization
 
 proc initPrivateKey*(hexString: string): PrivateKey {.noInit.} =
-  hexToByteArrayBE(hexString, result.Fraw_key)
+  hexToByteArrayBE(hexString, result.raw_key)
-  result.Fpublic_key = private_key_to_public_key(result)
+  result.public_key = private_key_to_public_key(result)
 
 proc initPublicKey*(hexString: string): PublicKey {.noInit.} =
   var b: array[65, byte]
@@ -68,4 +68,4 @@ proc sign_msg*(key: PrivateKey, message_hash: Hash[256]): Signature {.inline.} =
   ecdsa_sign(key, message_hash)
 
 proc `$`*(key: PrivateKey): string {.inline.} =
-  key.Fraw_key.toHex()
+  key.raw_key.toHex()

src/eth_keys.nim

@@ -8,7 +8,7 @@
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
 import ./datatypes
-export PublicKey, PrivateKey, Signature
+export PublicKey, PrivateKey, Signature, public_key, `==`
 
 import ./datatypes_interface
 export datatypes_interface

tests/test_key_and_signature_datastructures.nim

@@ -14,41 +14,13 @@ import  unittest
 
 suite "Test key and signature data structure":
 
-  # TODO: For now due to needing hex <-> uint256 conversion
-  # Testing r, s, v direct access is disabled
-  #
-  # test "Signing from private key object":
-  #   for person in [alice, bob, eve]:
-  #     let
-  #       pk = initPrivateKey(person.privkey)
-  #       signature = pk.sign_msg(MSG)
-
-  #     check:
-  #       signature.Fv == person.raw_sig.v
-  #       signature.Fr == hexToByteArrayBE[32](person.raw_sig.r)
-  #       signature.Fs == hexToByteArrayBE[32](person.raw_sig.s)
-
   test "Signing from private key object (ported from official eth-keys)":
     for person in [alice, bob, eve]:
       let
         pk = initPrivateKey(person.privkey)
         signature = pk.sign_msg(MSG)
 
-      check: verify_msg(pk.Fpublic_key, MSG, signature)
+      check: verify_msg(pk.public_key, MSG, signature)
-
-  # TODO: For now due to needing hex <-> uint256 conversion
-  # Testing r, s, v direct access is disabled
-  #
-  # test "Hash signing from private key object":
-  #   for person in [alice, bob, eve]:
-  #     let
-  #       pk = initPrivateKey(person.privkey)
-  #       signature = pk.sign_msg(MSG)
-
-  #     check:
-  #       signature.Fv == person.raw_sig.v
-  #       signature.Fr == hexToByteArrayBE[32](person.raw_sig.r)
-  #       signature.Fs == hexToByteArrayBE[32](person.raw_sig.s)
 
   test "Hash signing from private key object (ported from official eth-keys)":
     for person in [alice, bob, eve]:
@@ -56,7 +28,7 @@ suite "Test key and signature data structure":
         pk = initPrivateKey(person.privkey)
         signature = pk.sign_msg(MSGHASH)
 
-      check: verify_msg(pk.Fpublic_key, MSGHASH, signature)
+      check: verify_msg(pk.public_key, MSGHASH, signature)
 
   test "Recover public key from message":
     for person in [alice, bob, eve]:
@@ -66,7 +38,7 @@ suite "Test key and signature data structure":
 
         recovered_pubkey = recover_pubkey_from_msg(MSG, signature)
 
-      check: pk.Fpublic_key == recovered_pubkey
+      check: pk.public_key == recovered_pubkey
 
   test "Recover public key from message hash":
     for person in [alice, bob, eve]:
@@ -76,7 +48,7 @@ suite "Test key and signature data structure":
 
         recovered_pubkey = recover_pubkey_from_msg(MSGHASH, signature)
 
-      check: pk.Fpublic_key == recovered_pubkey
+      check: pk.public_key == recovered_pubkey
 
   test "Signature serialization and deserialization":
     for person in [alice, bob, eve]:

tests/test_private_public_key_consistency.nim

@@ -17,6 +17,6 @@ suite "Testing private -> public key conversion":
     for person in [alice, bob, eve]:
       let privkey = initPrivateKey(person.privkey)
 
-      let computed_pubkey = $privkey.Fpublic_key
+      let computed_pubkey = $privkey.public_key
 
       check: computed_pubkey == person.pubkey