Merge pull request #189 from thenewboston-developers/BC-271-cv-to-cv-block-confirmation

Block confirmations

Author: dmugtasimov

node/blockchain/facade.py

@@ -141,7 +141,7 @@ def get_next_block_identifier(self) -> Optional[BlockIdentifier]:
 
     @staticmethod
     def get_block_by_number(number) -> Block:
-        block = get_block_model().objects.get_block_by_number(_id=number)
+        block = get_block_model().objects.get_block_by_number(number)
         return block.get_block() if block else None
 
     @staticmethod

node/blockchain/inner_models/__init__.py

@@ -1,5 +1,6 @@
 from .account_state import AccountState  # noqa: F401
 from .block import Block, CoinTransferBlock, GenesisBlock, NodeDeclarationBlock  # noqa: F401
+from .block_confirmation import BlockConfirmation, BlockConfirmationMessage  # noqa: F401
 from .block_message import (  # noqa: F401
     BlockMessage, BlockMessageUpdate, CoinTransferBlockMessage, GenesisBlockMessage, NodeDeclarationBlockMessage,
     PVScheduleUpdateBlockMessage

node/blockchain/inner_models/block.py

@@ -44,8 +44,7 @@ def validate_signature(cls, values):
         if cls == Block:  # only child classes signature validation makes sense
             return values
 
-        validate_signature_helper(values)
-        return values
+        return validate_signature_helper(values)
 
     def validate_business_logic(self):
         self.message.validate_business_logic()

node/blockchain/inner_models/block_confirmation.py

@@ -0,0 +1,53 @@
+from pydantic import root_validator
+
+from node.blockchain.mixins.crypto import SignableMixin, validate_signature_helper
+from node.blockchain.mixins.validatable import ValidatableMixin
+from node.core.exceptions import ValidationError
+from node.core.utils.cryptography import derive_public_key
+from node.core.utils.types import non_negative_int
+
+from ..types import AccountNumber, Hash, NodeRole, Signature
+from .base import BaseModel
+
+
+class BlockConfirmationMessage(BaseModel, SignableMixin):
+    number: non_negative_int
+    hash: Hash  # noqa: A003
+
+
+class BlockConfirmation(ValidatableMixin, BaseModel):
+    signer: AccountNumber
+    signature: Signature
+    message: BlockConfirmationMessage
+
+    @classmethod
+    def create(cls, number, hash_, signing_key):
+        message = BlockConfirmationMessage(number=number, hash=hash_)
+        signer = derive_public_key(signing_key)
+        signature = message.make_signature(signing_key)
+
+        return cls(signer=signer, signature=signature, message=message)
+
+    @root_validator
+    def validate_signature(cls, values):
+        return validate_signature_helper(values)
+
+    def get_number(self):
+        return self.message.number
+
+    def get_hash(self):
+        return self.message.hash
+
+    def validate_signer(self, blockchain_facade):
+        if not blockchain_facade.has_blocks():
+            return
+
+        cv_identifiers = (node.identifier for node in blockchain_facade.yield_nodes({NodeRole.CONFIRMATION_VALIDATOR}))
+        if self.signer not in cv_identifiers:
+            raise ValidationError('Invalid block signer')
+
+    def validate_business_logic(self):
+        pass
+
+    def validate_blockchain_state_dependent(self, blockchain_facade):
+        self.validate_signer(blockchain_facade)

node/blockchain/inner_models/signed_change_request/base.py

@@ -55,8 +55,7 @@ def validate_signature(cls, values):
         if cls == SignedChangeRequest:  # only child classes signature validation makes sense
             return values
 
-        validate_signature_helper(values)
-        return values
+        return validate_signature_helper(values)
 
     def validate_business_logic(self):
         self.message.validate_business_logic()

node/blockchain/mixins/crypto.py

@@ -19,6 +19,8 @@ def validate_signature_helper(values: dict):
         # TODO(dmu) LOW: Pydantic does not recognize custom ValidationError. Fix?
         raise ValueError('Invalid signature')
 
+    return values
+
 
 class CryptoAuxiliaryMixin:
 

node/blockchain/mixins/validatable.py

@@ -1,7 +1,11 @@
 class ValidatableMixin:
 
-    def validate_business_logic(self):  # validate() is used by pydantic
+    def validate_business_logic(self):  # validate() is used by pydantic there we use a longer name
         raise NotImplementedError('Must be implemented in child class')
 
     def validate_blockchain_state_dependent(self, blockchain_facade):
         raise NotImplementedError('Must be implemented in child class')
+
+    def validate_all(self, blockchain_facade):
+        self.validate_business_logic()
+        self.validate_blockchain_state_dependent(blockchain_facade)

node/blockchain/models/__init__.py

@@ -1,5 +1,6 @@
 from .account_state import AccountState  # noqa: F401
 from .block import Block  # noqa: F401
+from .block_confirmation import BlockConfirmation  # noqa: F401
 from .node import Node  # noqa: F401
 from .pending_block import PendingBlock  # noqa: F401
 from .schedule import Schedule  # noqa: F401

node/blockchain/models/block_confirmation.py

@@ -0,0 +1,21 @@
+import uuid
+
+from djongo import models
+
+from node.core.models import CustomModel
+
+
+class BlockConfirmation(CustomModel):
+
+    _id = models.UUIDField(primary_key=True, default=uuid.uuid4)  # noqa: A003
+    number = models.PositiveBigIntegerField()
+    hash = models.CharField(max_length=128)  # noqa: A003
+    signer = models.CharField(max_length=64)  # noqa: A003
+    body = models.BinaryField()
+
+    class Meta:
+        unique_together = ('number', 'hash', 'signer')
+        ordering = unique_together
+
+    def __str__(self):
+        return f'block_number={self.number}, hash={self.hash}, signer={self.signer}'

node/blockchain/serializers/block_confirmation.py

@@ -0,0 +1,14 @@
+from rest_framework import serializers
+
+from node.blockchain.inner_models import BlockConfirmation
+from node.core.fields import PydanticModelBackedJSONField
+from node.core.serializers import ValidateUnknownFieldsMixin
+
+
+class BlockConfirmationSerializer(serializers.Serializer, ValidateUnknownFieldsMixin):
+    signer = serializers.CharField()
+    signature = serializers.CharField()
+    message = PydanticModelBackedJSONField()
+
+    def create(self, validated_data):
+        return BlockConfirmation.parse_obj(validated_data)