deserialize block

codexvalidator/blocks.nim

@@ -5,8 +5,10 @@ export blockid
 export blck except hash
 
 import ./blocks/serialization
+import ./blocks/deserialization
 
 export serialization.toBytes
+export deserialization.fromBytes
 
 import ./blocks/hashing
 

codexvalidator/blocks/deserialization.nim

@@ -0,0 +1,46 @@
+import ../basics
+import ../signatures
+import ../hashing
+import ../transaction
+import ../transaction/deserialization
+import ./blck
+import ./blockid
+import ./serialization
+
+func init*(
+  _: type BlockId,
+  message: BlockIdMessage
+): ?!BlockId =
+  success BlockId.init(
+    CommitteeMember(message.author),
+    message.round,
+    ? Hash.fromBytes(message.hash)
+  )
+
+func init*(
+  _: type Block,
+  message: BlockMessage
+): ?!Block =
+  success Block(
+    author: CommitteeMember(message.author),
+    round: message.round,
+    parents: message.parents.mapIt(? BlockId.init(it)),
+    transactions: message.transactions.mapIt(? Transaction.init(it))
+  )
+
+func init*(
+  _: type Signed[Block],
+  message: SignedBlockMessage
+): ?!Signed[Block] =
+  success Signed[Block].init(
+    ? Block.init(message.blck),
+    ? Identifier.fromBytes(message.signer),
+    ? Signature.fromBytes(message.signature)
+  )
+
+func fromBytes*(
+  _: type Signed[Block],
+  bytes: openArray[byte]
+): ?!Signed[Block] =
+  let message = ? Protobuf.decode(bytes, SignedBlockMessage).catch()
+  Signed[Block].init(message)

codexvalidator/hashing.nim

@@ -1,5 +1,6 @@
 import pkg/nimcrypto/sha2
 import pkg/nimcrypto/hash
+import ./basics
 
 export hash.`$`
 
@@ -12,5 +13,12 @@ func hash*(_: type Hash, bytes: openArray[byte]): Hash =
   result = context.finish()
   context.clear()
 
-func toBytes*(hash: Hash): auto =
-  hash.data
+func toBytes*(hash: Hash): seq[byte] =
+  @(hash.data)
+
+func fromBytes*(_: type Hash, bytes: openArray[byte]): ?!Hash =
+  if bytes.len != 32:
+    return failure "expected hash of 32 bytes, but got: " & $bytes.len
+  var data: array[32, byte]
+  data[0..<32] = bytes[0..<32]
+  success Hash(data: data)

codexvalidator/transaction/deserialization.nim

@@ -55,7 +55,7 @@ func init(_: type Groth16Proof, message: Groth16ProofMessage): Groth16Proof =
     )
   )
 
-func init(_: type Transaction, message: TransactionMessage): ?!Transaction =
+func init*(_: type Transaction, message: TransactionMessage): ?!Transaction =
   if message.version != TransactionVersion.version0.uint32:
     return failure "unsupported transaction version: " & $message.version
   let proofInput = ? StorageProofInput.init(message.proofInput)

tests/codexvalidator/blocks/testSerialization.nim

@@ -1,6 +1,7 @@
 import ../basics
 import codexvalidator/blocks
 import codexvalidator/blocks/serialization
+import codexvalidator/transaction
 import codexvalidator/transaction/serialization
 import codexvalidator/hashing
 import codexvalidator/signatures
@@ -35,3 +36,54 @@ suite "Block serialization":
     check protobuf.blck == BlockMessage.init(blck)
     check protobuf.signer == signed.signer.toBytes()
     check protobuf.signature == signed.signature.toBytes()
+
+  test "deserializes a signed block":
+    let signed = Signed[Block].example
+    let serialized = signed.toBytes()
+    let deserialized = Signed[Block].fromBytes(serialized)
+    check deserialized == success signed
+
+  test "deserialization fails when protobuf encoding is invalid":
+    let invalid = seq[byte].example
+    let deserialized = Signed[Block].fromBytes(invalid)
+    check deserialized.isFailure
+    check deserialized.errorOption.?msg == some "Invalid wire type"
+
+  test "deserialization fails when signer is invalid":
+    let signed = Signed[Block].example
+    var message = SignedBlockMessage.init(signed)
+    message.signer &= 42'u8
+    let invalid = Protobuf.encode(message)
+    let deserialized = Signed[Block].fromBytes(invalid)
+    check deserialized.isFailure
+    check deserialized.errorOption.?msg == some "invalid identifier"
+
+  test "deserialization fails when signature is invalid":
+    let signed = Signed[Block].example
+    var message = SignedBlockMessage.init(signed)
+    message.signature &= 42'u8
+    let invalid = Protobuf.encode(message)
+    let deserialized = Signed[Block].fromBytes(invalid)
+    check deserialized.isFailure
+    check deserialized.errorOption.?msg == some "invalid signature"
+
+  test "deserialization fails when parent block id is invalid":
+    let signed = Signed[Block].example
+    var message = SignedBlockMessage.init(signed)
+    let hash = array[32, byte].example
+    message.blck.parents &= BlockIdMessage(hash: @hash & 42'u8)
+    let invalid = Protobuf.encode(message)
+    let deserialized = Signed[Block].fromBytes(invalid)
+    check deserialized.isFailure
+    check deserialized.errorOption.?msg == some "expected hash of 32 bytes, but got: 33"
+
+  test "deserialization fails when transaction is invalid":
+    let signed = Signed[Block].example
+    var message = SignedBlockMessage.init(signed)
+    var transaction = TransactionMessage.init(Transaction.example)
+    transaction.version = 42'u8
+    message.blck.transactions &= transaction
+    let invalid = Protobuf.encode(message)
+    let deserialized = Signed[Block].fromBytes(invalid)
+    check deserialized.isFailure
+    check deserialized.errorOption.?msg == some "unsupported transaction version: 42"

tests/codexvalidator/testHashing.nim

@@ -0,0 +1,24 @@
+import ./basics
+import codexvalidator/hashing
+
+suite "Hashing":
+
+  test "serializes a hash to bytes":
+    let hash = Hash.example
+    let serialized = hash.toBytes()
+    check serialized == hash.data
+
+  test "deserializes a hash from bytes":
+    let hash = Hash.example
+    let serialized = hash.toBytes()
+    let deserialized = Hash.fromBytes(serialized)
+    check deserialized == success hash
+
+  test "deserialization fails when number of bytes is not 32":
+    let hash = Hash.example
+    let serialized = hash.toBytes()
+    let invalid = serialized & 42'u8
+    let deserialized = Hash.fromBytes(invalid)
+    check deserialized.isFailure
+    check deserialized.errorOption.?msg == some "expected hash of 32 bytes, but got: 33"
+

tests/tests.nim

@@ -1,4 +1,5 @@
 import ./codexvalidator/testSignatures
+import ./codexvalidator/testHashing
 import ./codexvalidator/transaction/testTransaction
 import ./codexvalidator/transaction/testSerialization
 import ./codexvalidator/transaction/testHashing