Skip to content

Commit

Permalink
add automatic parsing of field-level decorators (field~decorator) and…
Browse files Browse the repository at this point in the history 
… update handling of field signatures

Signed-off-by: Andrew Whitehead <[email protected]>
  • Loading branch information
@andrewwhitehead
andrewwhitehead committed Jun 7, 2019
1 parent 2613140 commit 0b3769f
Show file tree
Hide file tree
Showing 7 changed files with 137 additions and 123 deletions.
145 changes: 47 additions & 98 deletions agent/indy_catalyst_agent/messaging/agent_message.py
View file
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
"""Agent message base class and schema."""

from collections import OrderedDict
from typing import Dict, Union
from typing import Union
import uuid

from marshmallow import (
Expand All @@ -17,6 +17,7 @@

from .decorators.base import BaseDecoratorSet
from .decorators.default import DecoratorSet
from .decorators.signature_decorator import SignatureDecorator
from .decorators.thread_decorator import ThreadDecorator
from .models.base import (
BaseModel,
Expand All @@ -25,7 +26,6 @@
resolve_class,
resolve_meta_property,
)
from .models.field_signature import FieldSignature


class AgentMessageError(BaseModelError):
Expand All @@ -42,19 +42,13 @@ class Meta:
schema_class = None
message_type = None

def __init__(
self,
_id: str = None,
_decorators: BaseDecoratorSet = None,
_signatures: Dict[str, FieldSignature] = None,
):
def __init__(self, _id: str = None, _decorators: BaseDecoratorSet = None):
"""
Initialize base agent message object.
Args:
_id: Agent message id
_decorators: Message decorators
_signatures: Message signatures
Raises:
TypeError: If message type is missing on subclass Meta class
Expand All @@ -68,7 +62,6 @@ def __init__(
self._message_id = str(uuid.uuid4())
self._message_new_id = True
self._message_decorators = _decorators or DecoratorSet()
self._message_signatures = _signatures.copy() if _signatures else {}
if not self.Meta.message_type:
raise TypeError(
"Can't instantiate abstract class {} with no message_type".format(
Expand Down Expand Up @@ -140,31 +133,20 @@ def _decorators(self, value: BaseDecoratorSet):
"""Fetch the message's decorator set."""
self._message_decorators = value

@property
def _signatures(self) -> Dict[str, FieldSignature]:
"""
Fetch the dictionary of defined field signatures.
Returns:
A copy of the message_signatures for this message.
"""
return self._message_signatures.copy()

def get_signature(self, field_name: str) -> FieldSignature:
def get_signature(self, field_name: str) -> SignatureDecorator:
"""
Get the signature for a named field.
Args:
field_name: Field name to get signatures for
field_name: Field name to get the signature for
Returns:
A FieldSignature for the requested field name
A SignatureDecorator for the requested field name
"""
return self._message_signatures.get(field_name)
return self._decorators.field(field_name).get("sig")

def set_signature(self, field_name: str, signature: FieldSignature):
def set_signature(self, field_name: str, signature: SignatureDecorator):
"""
Add or replace the signature for a named field.
Expand All @@ -173,11 +155,11 @@ def set_signature(self, field_name: str, signature: FieldSignature):
signature: Signature for the field
"""
self._message_signatures[field_name] = signature
self._decorators.field(field_name)["sig"] = signature

async def sign_field(
self, field_name: str, signer_verkey: str, wallet: BaseWallet, timestamp=None
) -> FieldSignature:
) -> SignatureDecorator:
"""
Create and store a signature for a named field.
Expand All @@ -188,20 +170,20 @@ async def sign_field(
timestamp: Optional timestamp for signature
Returns:
A FieldSignature for newly created signature
A SignatureDecorator for newly created signature
Raises:
ValueError: If field_name doesn't exist on this message
"""
value = getattr(self, field_name, None)
if value is None:
raise ValueError(
raise BaseModelError(
"{} field has no value for signature: {}".format(
self.__class__.__name__, field_name
)
)
sig = await FieldSignature.create(value, signer_verkey, wallet, timestamp)
sig = await SignatureDecorator.create(value, signer_verkey, wallet, timestamp)
self.set_signature(field_name, sig)
return sig

Expand All @@ -226,15 +208,15 @@ async def verify_signed_field(
provided verkey
"""
if field_name not in self._message_signatures:
raise ValueError("Missing field signature: {}".format(field_name))
sig = self._message_signatures[field_name]
sig = self.get_signature(field_name)
if not sig:
raise BaseModelError("Missing field signature: {}".format(field_name))
if not await sig.verify(wallet):
raise ValueError(
raise BaseModelError(
"Field signature verification failed: {}".format(field_name)
)
if signer_verkey is not None and sig.signer != signer_verkey:
raise ValueError(
raise BaseModelError(
"Signer verkey of signature does not match: {}".format(field_name)
)
return sig.signer
Expand All @@ -250,8 +232,8 @@ async def verify_signatures(self, wallet: BaseWallet) -> bool:
True if all signatures verify, else false
"""
for sig in self._message_signatures.values():
if not await sig.verify(wallet):
for field in self._decorators.fields.values():
if "sig" in field and not await field["sig"].verify(wallet):
return False
return True

Expand Down Expand Up @@ -341,13 +323,8 @@ def __init__(self, *args, **kwargs):

@pre_load
def extract_decorators(self, data):
"""Extract decorator values."""
return self._decorators.extract_decorators(data)

@pre_load
def parse_signed_fields(self, data):
"""
Pre-load hook to parse all of the signed fields.
Pre-load hook to extract the decorators and check the signed fields.
Args:
data: Incoming data to parse
Expand All @@ -356,39 +333,32 @@ def parse_signed_fields(self, data):
Parsed and modified data
Raises:
ValidationError: If the field name prefix does not exist
ValidationError: If the field signature does not correlate
ValidationError: If a field signature does not correlate
to a field in the message
ValidationError: If the message defines both a field signature
and a value
and a value for the same field
ValidationError: If there is a missing field signature
"""
processed = self._decorators.extract_decorators(data)

expect_fields = resolve_meta_property(self, "signed_fields") or ()
found_signatures = {}
processed = {}
for field_name, field_value in data.items():
if field_name.endswith("~sig"):
pfx = field_name[:-4]
if not pfx:
raise ValidationError("Unsupported message property: ~sig")
if pfx not in expect_fields:
for field_name, field in self._decorators.fields.items():
if "sig" in field:
if field_name not in expect_fields:
raise ValidationError(
"Encountered unexpected field signature: {}".format(pfx)
f"Encountered unexpected field signature: {field_name}"
)
if pfx in data:
if field_name in processed:
raise ValidationError(
"Message defines both field signature and value: {}".format(pfx)
f"Message defines both field signature and value: {field_name}"
)
sig = FieldSignature.deserialize(field_value)
found_signatures[pfx] = sig
processed[pfx], _ts = sig.decode()
else:
processed[field_name] = field_value
found_signatures[field_name] = field["sig"]
processed[field_name], _ts = field["sig"].decode()
for field_name in expect_fields:
if field_name not in found_signatures:
raise ValidationError("Expected field signature: {}".format(field_name))
self._signatures = found_signatures
raise ValidationError(f"Expected field signature: {field_name}")
return processed

@post_load
Expand All @@ -406,24 +376,8 @@ def populate_decorators(self, obj):
obj._decorators = self._decorators
return obj

@post_load
def populate_signatures(self, obj):
"""
Post-load hook to populate signatures on the message.
Args:
obj: The AgentMessage object
Returns:
The AgentMessage object with populated signatures
"""
for field_name, sig in self._signatures.items():
obj.set_signature(field_name, sig)
return obj

@pre_dump
def check_decorators(self, obj):
def check_dump_decorators(self, obj):
"""
Pre-dump hook to validate and load the message decorators.
Expand All @@ -434,28 +388,23 @@ def check_decorators(self, obj):
BaseModelError: If a decorator does not validate
"""
self._decorators_dict = obj._decorators.to_dict()
return obj

@pre_dump
def check_signatures(self, obj):
"""
Pre-dump hook to check for the presence of required message signatures.
Args:
obj: The AgentMessage object
decorators = obj._decorators.copy()
signatures = OrderedDict()
for name, field in decorators.fields.items():
if "sig" in field:
signatures[name] = field["sig"].serialize()
del field["sig"]
self._decorators_dict = decorators.to_dict()
self._signatures = signatures

Raises:
ValidationError: If a signature is missing
"""
self._signatures = obj._signatures
# check existence of signatures
expect_fields = resolve_meta_property(self, "signed_fields") or ()
for field_name in expect_fields:
if field_name not in self._signatures:
raise ValidationError(
raise BaseModelError(
"Missing signature for field: {}".format(field_name)
)

return obj

@post_dump
Expand Down Expand Up @@ -492,5 +441,5 @@ def replace_signatures(self, data):
"""
for field_name, sig in self._signatures.items():
del data[field_name]
data["{}~sig".format(field_name)] = sig.serialize()
data["{}~sig".format(field_name)] = sig
return data
Loading

0 comments on commit 0b3769f

Please sign in to comment.