Protocol Class Reference

Detailed Description

Ubirch Protocol: handle signatures and UPP's and create message objects.

Inheritance diagram for Protocol:

Constructor & Destructor Documentation

__init__()

None __init__	(		self,
		dict	signatures = None
	)

Initialize the protocol.

Parameters

signatures

Previously known signatures

Member Function Documentation

_hash()

bytes _hash (   self, bytes  message  )

private

Hash the message before signing.

Override this method if a different hash algorithm is used. Default is SHA512.

Parameters

message

The message bytes

Returns

The digest in bytes

_sign()

bytes _sign (   self, UUID  uuid, bytes  message  )

private

Sign the request when finished.

Note

IMPORTANT: This function needs to be implemented with the Keystore of choice and its .find_signing_key() and .sign() functions

This function also takes care of the hashing, before signing, depending on the key type.

Parameters

uuid	The uuid of the sender to identify the correct key pair
message	The bytes to sign

Returns

NotImplementedError

Reimplemented in Proto.

_verify()

def _verify (   self, UUID  uuid, bytes  message, bytes  signature  )

private

Verify the message.

Note

IMPORTANT: This function needs to be implemented with the Keystore of choice and its .find_verifying_key() and .verify() functions

Throws exception if not verifiable. This function also takes care of the hashing, before verifying, depending on the key type.

Parameters

uuid	The uuid of the sender to identify the correct key pair
message	The message bytes to verify
signature	The signature to use for verification

Returns

NotImplementedError

Reimplemented in Proto.

get_saved_signatures()

dict get_saved_signatures

(

self

)

Get the saved signatures to store them persistently.

Returns

A dictionary of signatures (uuid -> bytes)

get_unpacked_index()

int get_unpacked_index	(		self,
		int	versionByte,
		int	targetField
	)

Get the index of a given target field for a UPP with the given version byte Throws a ValueError if the version byte (lower four bits) is invalid.

Parameters

versionByte	The first byte of an unpacked upp (first element of the list)
targetField	One off "UNPACKED_UPP_*"

Returns

The index of the field on success

keyreg_jsonstr_signed()

str keyreg_jsonstr_signed	(		self,
		UUID	uuid,
		dict	keyinfo_dict
	)

Takes a keyinfo-json-str and embeds into a signed json keyreg message.

:param uuid: the uuid of the device the keyinfo belongs to :param keyinfo_dict: the public key info object :return: the keyreg json as string

message_chained()

bytes message_chained	(		self,
		UUID	uuid,
		int	type,
		any	payload
	)

Create a new chained ubirch-protocol message.

Stores the context, the last signature, to be included in the next message.

Parameters

uuid	The uuid of the device that sends the message, part of the envelope
type	A hint of the type of message sent (0-255)
payload	The actual message payload

Returns

The encoded and signed message

message_signed()

bytes message_signed	(		self,
		UUID	uuid,
		int	type,
		any	payload,
		bool	save_signature = False
	)

Create a new signed ubirch-protocol message.

Parameters

uuid	The uuid of the device that sends the message, part of the envelope
type	A hint of the type of message sent (0-255)
payload	The actual message payload
save_signature	Save the signature of the created message so the next chained message contains it

Returns

The encoded and signed message

reset_signature()

None reset_signature	(		self,
		UUID	uuid
	)

Reset the last saved signature for this UUID.

Parameters

uuid	The UUID to reset

set_saved_signatures()

None set_saved_signatures	(		self,
		dict	signatures
	)

Set known signatures from devices we have talked to.

Parameters

signatures

The saved signatures as a dictionary (uuid -> bytes)

unpack_upp()

list unpack_upp	(		self,
		bytes	msgpackUPP
	)

Unpack a UPP (msgpack) Throws an exception if the UPP can't be unpacked Returns The unpacked upp as a list.

Parameters

msgpackUPP

The msgpack encoded message

Returns

The unpacked message

upp_msgpack_split_signature()

(bytes, bytes) upp_msgpack_split_signature	(		self,
			msgpackUPP
	)

Separate the signature from the msgpack.

Parameters

msgpackUPP

The msgpack encoded upp

Returns

A tuple consisting of the message without the signature and the signature

verify_signature()

bool verify_signature	(		self,
		UUID	uuid,
		bytes	msgpackUPP
	)

Verify the integrity of the message and decode the contents Raises an value error when the message is too short.

Parameters

uuid	The uuid of the sender of the message
msgpackUPP	The msgpack encoded message

Returns

The decoded message

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The documentation for this class was generated from the following file:

• /github/workspace/ubirch/ubirch_protocol.py