errors.py

# PSPTool - Display, extract and manipulate PSP firmware inside UEFI images
# Copyright (C) 2021 Christian Werling, Robert Buhren, Hans Niklas Jacob
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

from .crypto import PublicKey


class NoCertifyingKey(Exception):
    def __init__(self, signed_entity):
        self.signed_entity = signed_entity

    def __str__(self):
        key_id = self.signed_entity.certifying_key
        return f'There is no key with id {key_id.as_string()}, so {self.signed_entity} could not be verified!'


class SignatureInvalid(Exception):
    def __init__(self, signed_entity, pubkey: PublicKey):
        self.signed_entity = signed_entity
        self.pubkey = pubkey

    def __str__(self):
        return f'Signature for {self.signed_entity} is not signed by {self.pubkey}!'


class SignatureInconsistent(SignatureInvalid):
    def __str__(self):
        return f'Signature for {self.signed_entity} was verified successfully at least once, but could not be ' \
               f'verified by {self.pubkey}!'



class NonUniqueSignedEntity(Exception):
    def __init__(self, existing, new):
        self.existing = existing
        self.new = new

    def __str__(self):
        start = self.existing.body.get_address()
        end = start + self.existing.body.buffer_size
        return f'There was anlready a SignedEntity at {hex(start)}:{hex(end)} (existing={self.existing}, new={self.new})!'


class NonUniquePublicKeyEntity(Exception):
    def __init__(self, existing, new):
        self.existing = existing
        self.new = new

    def __str__(self):
        start = self.existing.key_id.get_address()
        return f'There was anlready a PublicKeyEntity with key_id at {hex(start)} (existing={self.existing}, new={self.new})!'