Method hashdata

pgpy/pgp.py:397–562

(self, subject)

        return h.digest() in self.attested_certifications

    def hashdata(self, subject):
        _data = bytearray()

        if isinstance(subject, str):
            try:
                subject = subject.encode('utf-8')
            except UnicodeEncodeError:
                subject = subject.encode('charmap')

        """
        All signatures are formed by producing a hash over the signature
        data, and then using the resulting hash in the signature algorithm.
        """

        if self.type == SignatureType.BinaryDocument:
            """
            For binary document signatures (type 0x00), the document data is
            hashed directly.
            """
            if isinstance(subject, (SKEData, IntegrityProtectedSKEData)):
                _data += subject.__bytearray__()
            else:
                _data += bytearray(subject)

        if self.type == SignatureType.CanonicalDocument:
            """
            For text document signatures (type 0x01), the
            document is canonicalized by converting line endings to <CR><LF>,
            and the resulting data is hashed.
            """
            _data += re.subn(br'\r?\n', b'\r\n', subject)[0]

        if self.type in {SignatureType.Generic_Cert, SignatureType.Persona_Cert, SignatureType.Casual_Cert,
                         SignatureType.Positive_Cert, SignatureType.CertRevocation, SignatureType.Subkey_Binding,
                         SignatureType.PrimaryKey_Binding}:
            """
            When a signature is made over a key, the hash data starts with the
            octet 0x99, followed by a two-octet length of the key, and then body
            of the key packet.  (Note that this is an old-style packet header for
            a key packet with two-octet length.) ...
            Key revocation signatures (types 0x20 and 0x28)
            hash only the key being revoked.
            """
            _s = b''
            if isinstance(subject, PGPUID):
                _s = subject._parent.hashdata

            elif isinstance(subject, PGPKey) and not subject.is_primary:
                _s = subject._parent.hashdata

            elif isinstance(subject, PGPKey) and subject.is_primary:
                _s = subject.hashdata

            if len(_s) > 0:
                _data += b'\x99' + self.int_to_bytes(len(_s), 2) + _s

        if self.type in {SignatureType.Subkey_Binding, SignatureType.PrimaryKey_Binding}:
            """