From 2bc632c29b019caaadb2edd259d5b6b94aea8a71 Mon Sep 17 00:00:00 2001
From: Dustin Brody <tersec@users.noreply.github.com>
Date: Mon, 18 Mar 2019 15:42:42 +0000
Subject: [PATCH] AttestationData.justified epoch ->
 AttestationData.source_epoch and AttestationData.latest_crosslink ->
 AttestationData.previous_crosslink; implement verify_merkle_branch and update
 process_deposit to use it; rm BeaconState.batched_block_roots;
 Transfer.{from, to} -> Transfer.{sender, recipient}; update Fork data type
 and code to use bytes4; implement int_to_bytes8 (close to metaprogramming
 time); adjust signed_root and all callers to use 0.5.0 calling signature;
 processDepositRoot -> processEth1Data (#182)

---
 beacon_chain/attestation_pool.nim |  4 +-
 beacon_chain/beacon_node.nim      |  4 +-
 beacon_chain/spec/beaconstate.nim | 82 ++++++++++++++++++++++++++-----
 beacon_chain/spec/datatypes.nim   | 73 +++++++++++++--------------
 beacon_chain/spec/helpers.nim     | 34 +++++++------
 beacon_chain/spec/validator.nim   |  4 +-
 beacon_chain/ssz.nim              |  3 +-
 beacon_chain/state_transition.nim | 28 +++++------
 beacon_chain/validator_pool.nim   |  2 +-
 tests/testutil.nim                |  7 +--
 10 files changed, 152 insertions(+), 89 deletions(-)

diff --git a/beacon_chain/attestation_pool.nim b/beacon_chain/attestation_pool.nim
index f9128f28f..5b3bd8067 100644
--- a/beacon_chain/attestation_pool.nim
+++ b/beacon_chain/attestation_pool.nim
@@ -239,7 +239,7 @@ proc add*(pool: var AttestationPool,
           slot = humaneSlotNum(attestation.data.slot),
           shard = attestation.data.shard,
           beaconBlockRoot = shortLog(attestation.data.beacon_block_root),
-          justifiedEpoch = humaneEpochNum(attestation.data.justified_epoch),
+          sourceEpoch = humaneEpochNum(attestation.data.source_epoch),
           justifiedBlockRoot = shortLog(attestation.data.justified_block_root),
           signature = shortLog(attestation.aggregate_signature),
           validations = a.validations.len() # TODO popcount of union
@@ -262,7 +262,7 @@ proc add*(pool: var AttestationPool,
         slot = humaneSlotNum(attestation.data.slot),
         shard = attestation.data.shard,
         beaconBlockRoot = shortLog(attestation.data.beacon_block_root),
-        justifiedEpoch = humaneEpochNum(attestation.data.justified_epoch),
+        sourceEpoch = humaneEpochNum(attestation.data.source_epoch),
         justifiedBlockRoot = shortLog(attestation.data.justified_block_root),
         signature = shortLog(attestation.aggregate_signature),
         validations = 1
diff --git a/beacon_chain/beacon_node.nim b/beacon_chain/beacon_node.nim
index a842b24d4..f6bc17ecb 100644
--- a/beacon_chain/beacon_node.nim
+++ b/beacon_chain/beacon_node.nim
@@ -387,7 +387,7 @@ proc proposeBlock(node: BeaconNode,
   let proposal = Proposal(
     slot: slot.uint64,
     shard: BEACON_CHAIN_SHARD_NUMBER,
-    block_root: Eth2Digest(data: signed_root(newBlock, "signature")),
+    block_root: Eth2Digest(data: signed_root(newBlock)),
     signature: ValidatorSig(),
   )
   newBlock.signature =
@@ -598,7 +598,7 @@ proc onAttestation(node: BeaconNode, attestation: Attestation) =
     slot = humaneSlotNum(attestation.data.slot),
     shard = attestation.data.shard,
     beaconBlockRoot = shortLog(attestation.data.beacon_block_root),
-    justifiedEpoch = humaneEpochNum(attestation.data.justified_epoch),
+    sourceEpoch = humaneEpochNum(attestation.data.source_epoch),
     justifiedBlockRoot = shortLog(attestation.data.justified_block_root),
     signature = shortLog(attestation.aggregate_signature)
 
diff --git a/beacon_chain/spec/beaconstate.nim b/beacon_chain/spec/beaconstate.nim
index 25241e4dc..4371bda59 100644
--- a/beacon_chain/spec/beaconstate.nim
+++ b/beacon_chain/spec/beaconstate.nim
@@ -16,6 +16,24 @@ func get_effective_balance*(state: BeaconState, index: ValidatorIndex): Gwei =
   ## validator with the given ``index``.
   min(state.validator_balances[index], MAX_DEPOSIT_AMOUNT)
 
+# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#verify_merkle_branch
+func verify_merkle_branch(leaf: Eth2Digest, proof: openarray[Eth2Digest], depth: uint64, index: uint64, root: Eth2Digest): bool =
+  ## Verify that the given ``leaf`` is on the merkle branch ``proof``
+  ## starting with the given ``root``.
+  var
+    value = leaf
+    buf: array[64, byte]
+
+  for i in 0 ..< depth.int:
+    if (index div (1'u64 shl i)) mod 2 != 0:
+      buf[0..31] = proof[i.int].data
+      buf[32..63] = value.data
+    else:
+      buf[0..31] = value.data
+      buf[32..63] = proof[i.int].data
+    value = eth2hash(buf)
+  value == root
+
 # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#process_deposit
 func process_deposit(state: var BeaconState, deposit: Deposit) =
   ## Process a deposit from Ethereum 1.0.
@@ -23,6 +41,42 @@ func process_deposit(state: var BeaconState, deposit: Deposit) =
 
   let deposit_input = deposit.deposit_data.deposit_input
 
+  ## Should equal 8 bytes for deposit_data.amount +
+  ##              8 bytes for deposit_data.timestamp +
+  ##              176 bytes for deposit_data.deposit_input
+  ## It should match the deposit_data in the eth1.0 deposit contract
+  ## TODO actual serialize func useful after all
+  var serialized_deposit_data: array[8 + 8 + 176, byte]
+  serialized_deposit_data[0..7] = deposit.deposit_data.amount.int_to_bytes8()
+  serialized_deposit_data[8..15] =
+    deposit.deposit_data.timestamp.int_to_bytes8()
+  serialized_deposit_data[16..63] = deposit_input.pubkey.getBytes()
+  serialized_deposit_data[64..95] = deposit_input.withdrawal_credentials.data
+  serialized_deposit_data[96..191] =
+    deposit_input.proof_of_possession.getBytes()
+
+  # Verify the Merkle branch
+  let merkle_branch_is_valid = verify_merkle_branch(
+    eth2hash(serialized_deposit_data),
+    deposit.proof,
+    DEPOSIT_CONTRACT_TREE_DEPTH,
+    deposit.index,
+    state.latest_eth1_data.deposit_root)
+  ## TODO enable this check, after using merkle_root (not in spec anymore, but
+  ## useful to construct proofs) to build proofs (i.e. the other child in each
+  ## pair of children at each level of the merkle tree), and injecting a proof
+  ## sequence corresponding to their hash values, into the `Deposits`, in that
+  ## tests/testutil.nim area of code. Currently it's checking against garbage,
+  ## either when creating genesis states or in the block processing of deposit
+  ## lists from Eth1Data.
+  # doAssert merkle_branch_is_valid
+
+  ## Increment the next deposit index we are expecting. Note that this
+  ## needs to be done here because while the deposit contract will never
+  ## create an invalid Merkle branch, it may admit an invalid deposit
+  ## object, and we need to be able to skip over it
+  state.deposit_index += 1
+
   ## if not validate_proof_of_possession(
   ##     state, pubkey, proof_of_possession, withdrawal_credentials):
   ##   return
@@ -89,19 +143,22 @@ func initiate_validator_exit*(state: var BeaconState,
   var validator = addr state.validator_registry[index]
   validator.initiated_exit = true
 
-# https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#exit_validator
+# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#exit_validator
 func exit_validator*(state: var BeaconState,
                      index: ValidatorIndex) =
   ## Exit the validator with the given ``index``.
   ## Note that this function mutates ``state``.
 
-  let validator = addr state.validator_registry[index]
+  let
+    validator = addr state.validator_registry[index]
+    delayed_activation_exit_epoch =
+      get_delayed_activation_exit_epoch(get_current_epoch(state))
 
   # The following updates only occur if not previous exited
-  if validator.exit_epoch <= get_delayed_activation_exit_epoch(get_current_epoch(state)):
+  if validator.exit_epoch <= delayed_activation_exit_epoch:
     return
 
-  validator.exit_epoch = get_delayed_activation_exit_epoch(get_current_epoch(state))
+  validator.exit_epoch = delayed_activation_exit_epoch
 
 func reduce_balance*(balance: var uint64, amount: uint64) =
   # Not in spec, but useful to avoid underflow.
@@ -228,7 +285,7 @@ func get_genesis_beacon_state*(
 
     # Recent state
     # latest_block_roots, latest_active_index_roots, latest_slashed_balances,
-    # latest_attestations, and batched_block_roots automatically initialized.
+    # and latest_attestations automatically initialized.
     latest_block_header: get_temporary_block_header(get_empty_block()),
   )
 
@@ -386,6 +443,7 @@ func update_validator_registry*(state: var BeaconState) =
   state.validator_registry_update_epoch = current_epoch
 
 # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#attestations-1
+# TODO this is https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#attestations now
 proc checkAttestation*(
     state: BeaconState, attestation: Attestation, flags: UpdateFlags): bool =
   ## Check that an attestation follows the rules of being included in the state
@@ -418,15 +476,15 @@ proc checkAttestation*(
     else:
       state.previous_justified_epoch
 
-  if not (attestation.data.justified_epoch == expected_justified_epoch):
+  if not (attestation.data.source_epoch == expected_justified_epoch):
     warn("Unexpected justified epoch",
       attestation_justified_epoch =
-        humaneEpochNum(attestation.data.justified_epoch),
+        humaneEpochNum(attestation.data.source_epoch),
       expected_justified_epoch = humaneEpochNum(expected_justified_epoch))
     return
 
   let expected_justified_block_root =
-    get_block_root(state, get_epoch_start_slot(attestation.data.justified_epoch))
+    get_block_root(state, get_epoch_start_slot(attestation.data.source_epoch))
   if not (attestation.data.justified_block_root == expected_justified_block_root):
     warn("Unexpected justified block root",
       attestation_justified_block_root = attestation.data.justified_block_root,
@@ -434,14 +492,14 @@ proc checkAttestation*(
     return
 
   if not (state.latest_crosslinks[attestation.data.shard] in [
-      attestation.data.latest_crosslink,
+      attestation.data.previous_crosslink,
       Crosslink(
         crosslink_data_root: attestation.data.crosslink_data_root,
         epoch: slot_to_epoch(attestation_data_slot))]):
     warn("Unexpected crosslink shard",
       state_latest_crosslinks_attestation_data_shard =
         state.latest_crosslinks[attestation.data.shard],
-      attestation_data_latest_crosslink = attestation.data.latest_crosslink,
+      attestation_data_previous_crosslink = attestation.data.previous_crosslink,
       epoch = humaneEpochNum(slot_to_epoch(attestation_data_slot)),
       crosslink_data_root = attestation.data.crosslink_data_root)
     return
@@ -545,7 +603,7 @@ proc makeAttestationData*(
     beacon_block_root: beacon_block_root,
     epoch_boundary_root: epoch_boundary_root,
     crosslink_data_root: Eth2Digest(), # Stub in phase0
-    latest_crosslink: state.latest_crosslinks[shard],
-    justified_epoch: state.current_justified_epoch,
+    previous_crosslink: state.latest_crosslinks[shard],
+    source_epoch: state.current_justified_epoch,
     justified_block_root: justified_block_root,
   )
diff --git a/beacon_chain/spec/datatypes.nim b/beacon_chain/spec/datatypes.nim
index 6d1721029..d8ff5445b 100644
--- a/beacon_chain/spec/datatypes.nim
+++ b/beacon_chain/spec/datatypes.nim
@@ -83,7 +83,7 @@ const
 
   # Deposit contract
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#deposit-contract
-  DEPOSIT_CONTRACT_TREE_DEPTH* = 2^5
+  DEPOSIT_CONTRACT_TREE_DEPTH* = 32
 
   # Gwei values
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#gwei-values
@@ -107,7 +107,8 @@ const
   ## Compile with -d:SLOTS_PER_EPOCH=4 for shorter epochs
 
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#initial-values
-  GENESIS_FORK_VERSION* = 0'u64
+  # TODO: in 0.5.0, GENESIS_FORK_VERSION defined as int, but used as [byte]
+  GENESIS_FORK_VERSION* = [0'u8, 0'u8, 0'u8, 0'u8]
   GENESIS_SLOT* = (2'u64^32).Slot
   GENESIS_EPOCH* = (GENESIS_SLOT.uint64 div SLOTS_PER_EPOCH).Epoch ##\
   ## slot_to_epoch(GENESIS_SLOT)
@@ -118,7 +119,7 @@ const
   BLS_WITHDRAWAL_PREFIX_BYTE* = 0'u8
 
   # Time parameters
-  # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#time-parameters
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#time-parameters
   SECONDS_PER_SLOT*{.intdefine.} = 6'u64 # Compile with -d:SECONDS_PER_SLOT=1 for 6x faster slots
   ## TODO consistent time unit across projects, similar to C++ chrono?
 
@@ -151,6 +152,9 @@ const
   MIN_VALIDATOR_WITHDRAWABILITY_DELAY* = 2'u64^8 ##\
   ## epochs (~27 hours)
 
+  PERSISTENT_COMMITTEE_PERIOD* = 2'u64^11 ##\
+  ## epochs (9 days)
+
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#state-list-lengths
   LATEST_RANDAO_MIXES_LENGTH* = 8192
   LATEST_ACTIVE_INDEX_ROOTS_LENGTH* = 8192 # 2'u64^13, epochs
@@ -190,7 +194,7 @@ type
     header_2*: BeaconBlockHeader ##\
     # Second block header
 
-  # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#attesterslashing
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#attesterslashing
   AttesterSlashing* = object
     slashable_attestation_1*: SlashableAttestation ## \
     ## First slashable attestation
@@ -211,7 +215,7 @@ type
     aggregate_signature*: ValidatorSig ## \
     ## Aggregate signature
 
-  # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#attestation
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#attestation
   Attestation* = object
     aggregation_bitfield*: seq[byte] ##\
     ## Attester aggregation bitfield
@@ -227,38 +231,31 @@ type
 
   # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#attestationdata
   AttestationData* = object
-    slot*: Slot ##\
-    ## Slot number
+    # LMD GHOST vote
+    slot*: Slot
+    beacon_block_root*: Eth2Digest
 
-    shard*: uint64 ##\
-    ## Shard number
+    # FFG vote
+    source_epoch*: Epoch
+    ## TODO epoch_boundary_root and justified_block_root are creatures of new
+    ## epoch processing and don't function quite as straightforwardly as just
+    ## renamings, so do that as part of epoch processing change.
+    epoch_boundary_root*: Eth2Digest
+    justified_block_root*: Eth2Digest
 
-    beacon_block_root*: Eth2Digest ##\
-    ## Hash of root of the signed beacon block
-
-    epoch_boundary_root*: Eth2Digest ##\
-    ## Hash of root of the ancestor at the epoch boundary
-
-    crosslink_data_root*: Eth2Digest ##\
-    ## Data from the shard since the last attestation
-
-    latest_crosslink*: Crosslink ##\
-    ## Last crosslink
-
-    justified_epoch*: Epoch ##\
-    ## Last justified epoch in the beacon state
-
-    justified_block_root*: Eth2Digest ##\
-    ## Hash of the last justified beacon block
+    # Crosslink vote
+    shard*: uint64
+    previous_crosslink*: Crosslink
+    crosslink_data_root*: Eth2Digest
 
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#attestationdataandcustodybit
   AttestationDataAndCustodyBit* = object
     data*: AttestationData
     custody_bit*: bool
 
-  # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#deposit
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#deposit
   Deposit* = object
-    branch*: seq[Eth2Digest] ##\
+    proof*: array[DEPOSIT_CONTRACT_TREE_DEPTH, Eth2Digest] ##\
     ## Branch in the deposit tree
 
     index*: uint64 ##\
@@ -289,12 +286,12 @@ type
     # Validator signature
     signature*: ValidatorSig
 
-  # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#transfer
+  # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#transfer
   Transfer* = object
-    from_field*: uint64 ##\
+    sender*: uint64 ##\
     ## Sender index
 
-    to*: uint64 ##\
+    recipient*: uint64 ##\
     ## Recipient index
 
     amount*: uint64 ##\
@@ -433,9 +430,8 @@ type
     ## `latest_block_header.state_root == ZERO_HASH` temporarily
     historical_roots*: seq[Eth2Digest]
 
-    # TOOD remove these, gone in 0.5
+    # TOOD remove, gone in 0.5
     latest_attestations*: seq[PendingAttestation]
-    batched_block_roots*: seq[Eth2Digest]
 
     # Ethereum 1.0 chain data
     latest_eth1_data*: Eth1Data
@@ -485,9 +481,14 @@ type
 
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#fork
   Fork* = object
-    previous_version*: uint64                     # Previous fork version
-    current_version*: uint64                      # Current fork version
-    epoch*: Epoch                                 # Fork epoch number
+    previous_version*: array[4, byte] ##\
+    ## Previous fork version
+
+    current_version*: array[4, byte] ##\
+    ## Current fork version
+
+    epoch*: Epoch ##\
+    ## Fork epoch number
 
   # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#eth1data
   Eth1Data* = object
diff --git a/beacon_chain/spec/helpers.nim b/beacon_chain/spec/helpers.nim
index a02d2deef..9fad0a288 100644
--- a/beacon_chain/spec/helpers.nim
+++ b/beacon_chain/spec/helpers.nim
@@ -69,24 +69,17 @@ func integer_squareroot*(n: SomeInteger): SomeInteger =
     y = (x + n div x) div 2
   x
 
-# https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#get_fork_version
-func get_fork_version*(fork: Fork, epoch: Epoch): uint64 =
+# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_fork_version
+func get_fork_version*(fork: Fork, epoch: Epoch): array[4, byte] =
   ## Return the fork version of the given ``epoch``.
   if epoch < fork.epoch:
     fork.previous_version
   else:
     fork.current_version
 
-# https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#get_domain
-func get_domain*(
-    fork: Fork, epoch: Epoch, domain_type: SignatureDomain): uint64 =
-  # Get the domain number that represents the fork meta and signature domain.
-  (get_fork_version(fork, epoch) shl 32) + domain_type.uint32
-
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#is_power_of_two
 func is_power_of_2*(v: uint64): bool = (v > 0'u64) and (v and (v-1)) == 0
 
-# https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#merkle_root
 func merkle_root*(values: openArray[Eth2Digest]): Eth2Digest =
   ## Merkleize ``values`` (where ``len(values)`` is a power of two) and return
   ## the Merkle root.
@@ -146,8 +139,8 @@ func is_surround_vote*(attestation_data_1: AttestationData,
                        attestation_data_2: AttestationData): bool =
   ## Check if ``attestation_data_1`` surrounds ``attestation_data_2``.
   let
-    source_epoch_1 = attestation_data_1.justified_epoch
-    source_epoch_2 = attestation_data_2.justified_epoch
+    source_epoch_1 = attestation_data_1.source_epoch
+    source_epoch_2 = attestation_data_2.source_epoch
     # RLP artifact
     target_epoch_1 = slot_to_epoch(attestation_data_1.slot)
     target_epoch_2 = slot_to_epoch(attestation_data_2.slot)
@@ -159,7 +152,7 @@ func is_active_validator*(validator: Validator, epoch: Epoch): bool =
   ### Check if ``validator`` is active
   validator.activation_epoch <= epoch and epoch < validator.exit_epoch
 
-# https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#get_active_validator_indices
+# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_active_validator_indices
 func get_active_validator_indices*(validators: openArray[Validator], epoch: Epoch): seq[ValidatorIndex] =
   ## Gets indices of active validators from validators
   for idx, val in validators:
@@ -210,7 +203,7 @@ func get_active_index_root(state: BeaconState, epoch: Epoch): Eth2Digest =
   state.latest_active_index_roots[epoch mod LATEST_ACTIVE_INDEX_ROOTS_LENGTH]
 
 # https://github.com/ethereum/eth2.0-specs/blob/v0.2.0/specs/core/0_beacon-chain.md#bytes_to_int
-func bytes_to_int*(data: seq[byte]): uint64 =
+func bytes_to_int*(data: openarray[byte]): uint64 =
   doAssert data.len == 8
 
   # Little-endian data representation
@@ -219,7 +212,7 @@ func bytes_to_int*(data: seq[byte]): uint64 =
     result = result * 256 + data[i]
 
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#int_to_bytes1-int_to_bytes2-
-# Have 1, 4, and 32-byte versions. 2+ more and maybe worth metaprogramming.
+# Have 1, 4, 8, and 32-byte versions. 1+ more and maybe worth metaprogramming.
 func int_to_bytes32*(x: uint64): array[32, byte] =
   ## Little-endian data representation
   ## TODO remove uint64 when those callers fade away
@@ -228,6 +221,10 @@ func int_to_bytes32*(x: uint64): array[32, byte] =
 
 func int_to_bytes32*(x: Epoch): array[32, byte] {.borrow.}
 
+func int_to_bytes8*(x: uint64): array[8, byte] =
+  for i in 0 ..< 8:
+    result[i] = byte((x shr i*8) and 0xff)
+
 func int_to_bytes1*(x: int): array[1, byte] =
   doAssert x >= 0
   doAssert x < 256
@@ -244,6 +241,15 @@ func int_to_bytes4*(x: uint64): array[4, byte] =
   result[2] = ((x shr 16) and 0xff).byte
   result[3] = ((x shr 24) and 0xff).byte
 
+# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_domain
+func get_domain*(
+    fork: Fork, epoch: Epoch, domain_type: SignatureDomain): uint64 =
+  # Get the domain number that represents the fork meta and signature domain.
+  var buf: array[8, byte]
+  buf[0..3] = get_fork_version(fork, epoch)
+  buf[4..7] = int_to_bytes4(domain_type.uint64)
+  bytes_to_int(buf)
+
 # https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#generate_seed
 func generate_seed*(state: BeaconState, epoch: Epoch): Eth2Digest =
   # Generate a seed for the given ``epoch``.
diff --git a/beacon_chain/spec/validator.nim b/beacon_chain/spec/validator.nim
index 040ff77f5..9d510714d 100644
--- a/beacon_chain/spec/validator.nim
+++ b/beacon_chain/spec/validator.nim
@@ -12,8 +12,8 @@ import
   ../ssz,
   ./crypto, ./datatypes, ./digest, ./helpers
 
-# https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#get_shuffling
-# https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#get_permuted_index
+# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_shuffling
+# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#get_permuted_index
 func get_shuffled_seq*(seed: Eth2Digest,
                        list_size: uint64,
                        ): seq[ValidatorIndex] =
diff --git a/beacon_chain/ssz.nim b/beacon_chain/ssz.nim
index 9b9e085ce..60e21f615 100644
--- a/beacon_chain/ssz.nim
+++ b/beacon_chain/ssz.nim
@@ -315,12 +315,13 @@ func hash_tree_root*[T: object|tuple](x: T): array[32, byte] =
       h.update hash_tree_root(field.toSSZType)
 
 # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/simple-serialize.md#signed-roots
-func signed_root*[T: object](x: T, ignored: string = "sig"): array[32, byte] =
+func signed_root*[T: object](x: T): array[32, byte] =
   # TODO write tests for this (check vs hash_tree_root)
 
   var found_field_name = false
 
   ## TODO this isn't how 0.5 defines signed_root, but works well enough
+  ## for now.
   withHash:
     for name, field in x.fieldPairs:
       if name == "signature":
diff --git a/beacon_chain/state_transition.nim b/beacon_chain/state_transition.nim
index 876acc396..6fbda28d1 100644
--- a/beacon_chain/state_transition.nim
+++ b/beacon_chain/state_transition.nim
@@ -51,11 +51,11 @@ func verifyBlockSignature(state: BeaconState, blck: BeaconBlock): bool =
     proposal = Proposal(
       slot: blck.slot.uint64,
       shard: BEACON_CHAIN_SHARD_NUMBER,
-      block_root: Eth2Digest(data: signed_root(blck, "signature")),
+      block_root: Eth2Digest(data: signed_root(blck)),
       signature: blck.signature)
   bls_verify(
     proposer.pubkey,
-    signed_root(proposal, "signature"),
+    signed_root(proposal),
     proposal.signature,
     get_domain(state.fork, get_current_epoch(state), DOMAIN_BEACON_BLOCK))
 
@@ -126,8 +126,8 @@ proc processRandao(
 
   true
 
-# https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#eth1-data
-func processDepositRoot(state: var BeaconState, blck: BeaconBlock) =
+# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#eth1-data-1
+func processEth1Data(state: var BeaconState, blck: BeaconBlock) =
   # TODO verify that there's at most one match
   for x in state.eth1_data_votes.mitems():
     if blck.body.eth1_data == x.eth1_data:
@@ -344,7 +344,7 @@ proc processTransfers(state: var BeaconState, blck: BeaconBlock,
     return false
 
   for transfer in blck.body.transfers:
-    let from_balance = state.validator_balances[transfer.from_field.int]
+    let from_balance = state.validator_balances[transfer.sender.int]
 
     if not (from_balance >= transfer.amount):
       notice "Transfer: source balance too low for amount"
@@ -365,13 +365,13 @@ proc processTransfers(state: var BeaconState, blck: BeaconBlock,
 
     if not (get_current_epoch(state) >=
         state.validator_registry[
-          transfer.from_field.int].withdrawable_epoch or
-        state.validator_registry[transfer.from_field.int].activation_epoch ==
+          transfer.sender.int].withdrawable_epoch or
+        state.validator_registry[transfer.sender.int].activation_epoch ==
           FAR_FUTURE_EPOCH):
       notice "Transfer: epoch mismatch"
       return false
 
-    let wc = state.validator_registry[transfer.from_field.int].
+    let wc = state.validator_registry[transfer.sender.int].
       withdrawal_credentials
     if not (wc.data[0] == BLS_WITHDRAWAL_PREFIX_BYTE and
             wc.data[1..^1] == eth2hash(transfer.pubkey.getBytes).data[1..^1]):
@@ -389,9 +389,9 @@ proc processTransfers(state: var BeaconState, blck: BeaconBlock,
 
     # TODO https://github.com/ethereum/eth2.0-specs/issues/727
     reduce_balance(
-      state.validator_balances[transfer.from_field.int],
+      state.validator_balances[transfer.sender.int],
       transfer.amount + transfer.fee)
-    state.validator_balances[transfer.to.int] += transfer.amount
+    state.validator_balances[transfer.recipient.int] += transfer.amount
     state.validator_balances[
       get_beacon_proposer_index(state, state.slot)] += transfer.fee
 
@@ -431,8 +431,6 @@ func processSlot(state: var BeaconState, previous_block_root: Eth2Digest) =
   # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#block-roots
   state.latest_block_roots[(state.slot - 1) mod SLOTS_PER_HISTORICAL_ROOT] =
     previous_block_root
-  if state.slot mod SLOTS_PER_HISTORICAL_ROOT == 0:
-    state.batched_block_roots.add(merkle_root(state.latest_block_roots))
 
 proc processBlock(
     state: var BeaconState, blck: BeaconBlock, flags: UpdateFlags): bool =
@@ -478,7 +476,7 @@ proc processBlock(
   if not processRandao(state, blck, flags):
     return false
 
-  processDepositRoot(state, blck)
+  processEth1Data(state, blck)
 
   if not processProposerSlashings(state, blck, flags):
     return false
@@ -534,7 +532,6 @@ func process_slashings(state: var BeaconState) =
     current_epoch = get_current_epoch(state)
     active_validator_indices = get_active_validator_indices(
       state.validator_registry, current_epoch)
-    # 0.4.0 spec doesn't use this helper function?
     total_balance = get_total_balance(state, active_validator_indices)
 
   for index, validator in state.validator_registry:
@@ -591,7 +588,6 @@ func processEpoch(state: var BeaconState) =
   if (state.slot + 1) mod SLOTS_PER_EPOCH != 0:
     return
 
-  # https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#helper-variables
   let
     current_epoch = get_current_epoch(state)
     previous_epoch = get_previous_epoch(state)
@@ -998,7 +994,7 @@ func processEpoch(state: var BeaconState) =
       not (slot_to_epoch(it.data.slot) < current_epoch)
     )
 
-# https://github.com/ethereum/eth2.0-specs/blob/0.4.0/specs/core/0_beacon-chain.md#state-root-verification
+# https://github.com/ethereum/eth2.0-specs/blob/v0.5.0/specs/core/0_beacon-chain.md#state-root-verification
 proc verifyStateRoot(state: BeaconState, blck: BeaconBlock): bool =
   let state_root = hash_tree_root_final(state)
   if state_root != blck.state_root:
diff --git a/beacon_chain/validator_pool.nim b/beacon_chain/validator_pool.nim
index 46d493202..ede42c3d5 100644
--- a/beacon_chain/validator_pool.nim
+++ b/beacon_chain/validator_pool.nim
@@ -30,7 +30,7 @@ proc signBlockProposal*(v: AttachedValidator, fork: Fork,
     await sleepAsync(1)
     let proposalRoot = hash_tree_root_final(proposal)
 
-    result = bls_sign(v.privKey, signed_root(proposal, "signature"),
+    result = bls_sign(v.privKey, signed_root(proposal),
       get_domain(fork, slot_to_epoch(proposal.slot), DOMAIN_BEACON_BLOCK))
   else:
     # TODO:
diff --git a/tests/testutil.nim b/tests/testutil.nim
index abfdec495..f2236652c 100644
--- a/tests/testutil.nim
+++ b/tests/testutil.nim
@@ -47,6 +47,7 @@ func makeDeposit(i: int, flags: UpdateFlags): Deposit =
       bls_sign(privkey, hash_tree_root_final(proof_of_possession_data).data, domain)
 
   Deposit(
+    index: i.uint64,
     deposit_data: DepositData(
       deposit_input: DepositInput(
         pubkey: pubkey,
@@ -85,7 +86,7 @@ proc addBlock*(
   # Ferret out remaining GENESIS_EPOCH == 0 assumptions in test code
   doAssert allIt(
     body.attestations,
-    it.data.latest_crosslink.epoch >= GENESIS_EPOCH)
+    it.data.previous_crosslink.epoch >= GENESIS_EPOCH)
 
   let
     # Index from the new state, but registry from the old state.. hmm...
@@ -125,10 +126,10 @@ proc addBlock*(
     signed_data = Proposal(
       slot: new_block.slot.uint64,
       shard: BEACON_CHAIN_SHARD_NUMBER,
-      block_root: Eth2Digest(data: signed_root(new_block, "signature")),
+      block_root: Eth2Digest(data: signed_root(new_block)),
       signature: ValidatorSig(),
     )
-    proposal_hash = signed_root(signed_data, "signature")
+    proposal_hash = signed_root(signed_data)
 
   doAssert proposerPrivkey.pubKey() == proposer.pubkey,
     "signature key should be derived from private key! - wrong privkey?"