refactor(core): create and use protobuf uvarint writer

core/src/apps/common/writers.py

@@ -99,3 +99,13 @@ def write_bitcoin_varint(w: Writer, n: int) -> None:
         w.append((n >> 8) & 0xFF)
         w.append((n >> 16) & 0xFF)
         w.append((n >> 24) & 0xFF)
+
+
+def write_uvarint(w: Writer, n: int) -> None:
+    ensure(n >= 0 and n <= 0xFFFF_FFFF_FFFF_FFFF)
+    shifted = 1
+    while shifted:
+        shifted = n >> 7
+        byte = (n & 0x7F) | (0x80 if shifted else 0x00)
+        w.append(byte)
+        n = shifted

core/src/apps/eos/actions/__init__.py

@@ -73,7 +73,7 @@ async def process_unknown_action(
     ctx: wire.Context, w: Writer, action: EosTxActionAck
 ) -> None:
     checksum = HashWriter(sha256())
-    writers.write_variant32(checksum, action.unknown.data_size)
+    writers.write_uvarint(checksum, action.unknown.data_size)
     checksum.extend(action.unknown.data_chunk)
 
     writers.write_bytes_unchecked(w, action.unknown.data_chunk)

core/src/apps/eos/sign_tx.py

@@ -28,7 +28,7 @@ async def sign_tx(ctx: wire.Context, msg: EosSignTx, keychain: Keychain) -> EosS
     sha = HashWriter(sha256())
     await _init(ctx, sha, msg)
     await _actions(ctx, sha, msg.num_actions)
-    writers.write_variant32(sha, 0)
+    writers.write_uvarint(sha, 0)
     writers.write_bytes_fixed(sha, bytearray(32), 32)
 
     digest = sha.get_digest()
@@ -42,8 +42,8 @@ async def sign_tx(ctx: wire.Context, msg: EosSignTx, keychain: Keychain) -> EosS
 async def _init(ctx: wire.Context, sha: HashWriter, msg: EosSignTx) -> None:
     writers.write_bytes_fixed(sha, msg.chain_id, 32)
     writers.write_header(sha, msg.header)
-    writers.write_variant32(sha, 0)
+    writers.write_uvarint(sha, 0)
-    writers.write_variant32(sha, msg.num_actions)
+    writers.write_uvarint(sha, msg.num_actions)
 
     await require_sign_tx(ctx, msg.num_actions)
 

core/src/apps/eos/writers.py

@@ -1,5 +1,3 @@
-from protobuf import dump_uvarint
-
 from apps.common.writers import (
     write_bytes_fixed,
     write_bytes_unchecked,
@@ -7,6 +5,7 @@ from apps.common.writers import (
     write_uint16_le,
     write_uint32_le,
     write_uint64_le,
+    write_uvarint,
 )
 
 if False:
@@ -33,19 +32,19 @@ if False:
 
 def write_auth(w: Writer, auth: EosAuthorization) -> None:
     write_uint32_le(w, auth.threshold)
-    write_variant32(w, len(auth.keys))
+    write_uvarint(w, len(auth.keys))
     for key in auth.keys:
-        write_variant32(w, key.type)
+        write_uvarint(w, key.type)
         write_bytes_fixed(w, key.key, 33)
         write_uint16_le(w, key.weight)
 
-    write_variant32(w, len(auth.accounts))
+    write_uvarint(w, len(auth.accounts))
     for account in auth.accounts:
         write_uint64_le(w, account.account.actor)
         write_uint64_le(w, account.account.permission)
         write_uint16_le(w, account.weight)
 
-    write_variant32(w, len(auth.waits))
+    write_uvarint(w, len(auth.waits))
     for wait in auth.waits:
         write_uint32_le(w, wait.wait_sec)
         write_uint16_le(w, wait.weight)
@@ -55,9 +54,9 @@ def write_header(hasher: Writer, header: EosTxHeader) -> None:
     write_uint32_le(hasher, header.expiration)
     write_uint16_le(hasher, header.ref_block_num)
     write_uint32_le(hasher, header.ref_block_prefix)
-    write_variant32(hasher, header.max_net_usage_words)
+    write_uvarint(hasher, header.max_net_usage_words)
     write_uint8(hasher, header.max_cpu_usage_ms)
-    write_variant32(hasher, header.delay_sec)
+    write_uvarint(hasher, header.delay_sec)
 
 
 def write_action_transfer(w: Writer, msg: EosActionTransfer) -> None:
@@ -106,7 +105,7 @@ def write_action_refund(w: Writer, msg: EosActionRefund) -> None:
 def write_action_voteproducer(w: Writer, msg: EosActionVoteProducer) -> None:
     write_uint64_le(w, msg.voter)
     write_uint64_le(w, msg.proxy)
-    write_variant32(w, len(msg.producers))
+    write_uvarint(w, len(msg.producers))
     for producer in msg.producers:
         write_uint64_le(w, producer)
 
@@ -146,7 +145,7 @@ def write_action_newaccount(w: Writer, msg: EosActionNewAccount) -> None:
 def write_action_common(w: Writer, msg: EosActionCommon) -> None:
     write_uint64_le(w, msg.account)
     write_uint64_le(w, msg.name)
-    write_variant32(w, len(msg.authorization))
+    write_uvarint(w, len(msg.authorization))
     for authorization in msg.authorization:
         write_uint64_le(w, authorization.actor)
         write_uint64_le(w, authorization.permission)
@@ -157,10 +156,6 @@ def write_asset(w: Writer, asset: EosAsset) -> None:
     write_uint64_le(w, asset.symbol)
 
 
-def write_variant32(w: Writer, value: int) -> None:
-    dump_uvarint(w.extend, value)
-
-
 def write_bytes_prefixed(w: Writer, data: bytes) -> None:
-    write_variant32(w, len(data))
+    write_uvarint(w, len(data))
     write_bytes_unchecked(w, data)