From 3e1ce94961200cc797f59740acc35013c8c0e78b Mon Sep 17 00:00:00 2001
From: Yuriy Glukhov <yuriy.glukhov@gmail.com>
Date: Mon, 5 Aug 2019 23:03:41 +0300
Subject: [PATCH] Moved Transaction encodings from nimbus

---
 eth/common/transaction.nim | 72 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 eth/common/transaction.nim

diff --git a/eth/common/transaction.nim b/eth/common/transaction.nim
new file mode 100644
index 0000000..63717e4
--- /dev/null
+++ b/eth/common/transaction.nim
@@ -0,0 +1,72 @@
+import
+  eth/[common, rlp, keys], nimcrypto
+
+proc initTransaction*(nonce: AccountNonce, gasPrice, gasLimit: GasInt, to: EthAddress,
+  value: UInt256, payload: Blob, V: byte, R, S: UInt256, isContractCreation = false): Transaction =
+  result.accountNonce = nonce
+  result.gasPrice = gasPrice
+  result.gasLimit = gasLimit
+  result.to = to
+  result.value = value
+  result.payload = payload
+  result.V = V
+  result.R = R
+  result.S = S
+  result.isContractCreation = isContractCreation
+
+type
+  TransHashObj = object
+    accountNonce:  AccountNonce
+    gasPrice:      GasInt
+    gasLimit:      GasInt
+    to {.rlpCustomSerialization.}: EthAddress
+    value:         UInt256
+    payload:       Blob
+    mIsContractCreation {.rlpIgnore.}: bool
+
+proc read(rlp: var Rlp, t: var TransHashObj, _: type EthAddress): EthAddress {.inline.} =
+  if rlp.blobLen != 0:
+    result = rlp.read(EthAddress)
+  else:
+    t.mIsContractCreation = true
+
+proc append(rlpWriter: var RlpWriter, t: TransHashObj, a: EthAddress) {.inline.} =
+  if t.mIsContractCreation:
+    rlpWriter.append("")
+  else:
+    rlpWriter.append(a)
+
+const
+  EIP155_CHAIN_ID_OFFSET = 35
+
+func rlpEncode*(transaction: Transaction): auto =
+  # Encode transaction without signature
+  return rlp.encode(TransHashObj(
+    accountNonce: transaction.accountNonce,
+    gasPrice: transaction.gasPrice,
+    gasLimit: transaction.gasLimit,
+    to: transaction.to,
+    value: transaction.value,
+    payload: transaction.payload,
+    mIsContractCreation: transaction.isContractCreation
+    ))
+
+func rlpEncodeEIP155*(tx: Transaction): auto =
+  let V = (tx.V.int - EIP155_CHAIN_ID_OFFSET) div 2
+  # Encode transaction without signature
+  return rlp.encode(Transaction(
+    accountNonce: tx.accountNonce,
+    gasPrice: tx.gasPrice,
+    gasLimit: tx.gasLimit,
+    to: tx.to,
+    value: tx.value,
+    payload: tx.payload,
+    isContractCreation: tx.isContractCreation,
+    V: V.byte,
+    R: 0.u256,
+    S: 0.u256
+    ))
+
+func txHashNoSignature*(tx: Transaction): Hash256 =
+  # Hash transaction without signature
+  return keccak256.digest(if tx.V.int >= EIP155_CHAIN_ID_OFFSET: tx.rlpEncodeEIP155 else: tx.rlpEncode)