follow-up prev. sanity check OP_RETURN outputs

based on 86c63a3a08

electrum/plugins/hw_wallet/plugin.py

@@ -26,7 +26,9 @@
 
 from electrum.plugin import BasePlugin, hook
 from electrum.i18n import _
-from electrum.bitcoin import is_address
+from electrum.bitcoin import is_address, TYPE_SCRIPT
+from electrum.util import bfh
+from electrum.transaction import opcodes
 
 
 class HW_PluginBase(BasePlugin):
@@ -87,3 +89,15 @@ def is_any_tx_output_on_change_branch(tx):
             if index[0] == 1:
                 return True
     return False
+
+
+def trezor_validate_op_return_output_and_get_data(_type, address, amount):
+    if _type != TYPE_SCRIPT:
+        raise Exception("Unexpected output type: {}".format(_type))
+    script = bfh(address)
+    if not (script[0] == opcodes.OP_RETURN and
+            script[1] == len(script) - 2 and script[1] <= 75):
+        raise Exception(_("Only OP_RETURN scripts, with one constant push, are supported."))
+    if amount != 0:
+        raise Exception(_("Amount for OP_RETURN output must be zero."))
+    return script[2:]

electrum/plugins/keepkey/keepkey.py

@@ -15,7 +15,7 @@ from electrum.wallet import Standard_Wallet
 from electrum.base_wizard import ScriptTypeNotSupported
 
 from ..hw_wallet import HW_PluginBase
-from ..hw_wallet.plugin import is_any_tx_output_on_change_branch
+from ..hw_wallet.plugin import is_any_tx_output_on_change_branch, trezor_validate_op_return_output_and_get_data
 
 
 # TREZOR initialization methods
@@ -382,7 +382,7 @@ class KeepKeyPlugin(HW_PluginBase):
             txoutputtype.amount = amount
             if _type == TYPE_SCRIPT:
                 txoutputtype.script_type = self.types.PAYTOOPRETURN
-                txoutputtype.op_return_data = bfh(address)[2:]
+                txoutputtype.op_return_data = trezor_validate_op_return_output_and_get_data(_type, address, amount)
             elif _type == TYPE_ADDRESS:
                 if is_segwit_address(address):
                     txoutputtype.script_type = self.types.PAYTOWITNESS

electrum/plugins/safe_t/safe_t.py

@@ -13,7 +13,7 @@ from electrum.keystore import Hardware_KeyStore, is_xpubkey, parse_xpubkey, xtyp
 from electrum.base_wizard import ScriptTypeNotSupported
 
 from ..hw_wallet import HW_PluginBase
-from ..hw_wallet.plugin import is_any_tx_output_on_change_branch
+from ..hw_wallet.plugin import is_any_tx_output_on_change_branch, trezor_validate_op_return_output_and_get_data
 
 
 # Safe-T mini initialization methods
@@ -453,7 +453,7 @@ class SafeTPlugin(HW_PluginBase):
             txoutputtype.amount = amount
             if _type == TYPE_SCRIPT:
                 txoutputtype.script_type = self.types.OutputScriptType.PAYTOOPRETURN
-                txoutputtype.op_return_data = bfh(address)[2:]
+                txoutputtype.op_return_data = trezor_validate_op_return_output_and_get_data(_type, address, amount)
             elif _type == TYPE_ADDRESS:
                 txoutputtype.script_type = self.types.OutputScriptType.PAYTOADDRESS
                 txoutputtype.address = address

electrum/plugins/trezor/trezor.py

@@ -13,7 +13,7 @@ from electrum.keystore import Hardware_KeyStore, is_xpubkey, parse_xpubkey, xtyp
 from electrum.base_wizard import ScriptTypeNotSupported
 
 from ..hw_wallet import HW_PluginBase
-from ..hw_wallet.plugin import is_any_tx_output_on_change_branch
+from ..hw_wallet.plugin import is_any_tx_output_on_change_branch, trezor_validate_op_return_output_and_get_data
 
 
 # TREZOR initialization methods
@@ -464,7 +464,7 @@ class TrezorPlugin(HW_PluginBase):
             txoutputtype.amount = amount
             if _type == TYPE_SCRIPT:
                 txoutputtype.script_type = self.types.OutputScriptType.PAYTOOPRETURN
-                txoutputtype.op_return_data = bfh(address)[2:]
+                txoutputtype.op_return_data = trezor_validate_op_return_output_and_get_data(_type, address, amount)
             elif _type == TYPE_ADDRESS:
                 txoutputtype.script_type = self.types.OutputScriptType.PAYTOADDRESS
                 txoutputtype.address = address