model

package
v0.27.0 Latest Latest
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 Go to latest Published: Feb 26, 2024 License: MIT Imports: 24 Imported by: 9

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Index

Constants

View Source 
const (
	InvalidEd25519PublicKey    = Error("InvalidEd25519PublicKey")
	InconsistentKeyBundleError = Error("InconsistentKeyBundleError")
)

Error definitions

View Source 
const (

	// BundleType - the attribute under which the signed server bundle is stored...
	BundleType = KeyType("server_key_bundle")

	// KeyTypeServerOnion - a cwtch address
	KeyTypeServerOnion = KeyType("bulletin_board_onion") // bulletin board

	// KeyTypeTokenOnion - a cwtch peer with a PoW based token protocol
	KeyTypeTokenOnion = KeyType("token_service_onion")

	//KeyTypePrivacyPass - a privacy pass based token server
	KeyTypePrivacyPass = KeyType("privacy_pass_public_key")
)
View Source 
const CurrentGroupVersion = 4

CurrentGroupVersion is used to set the version of newly created groups and make sure group structs stored are correct and up to date

View Source 
const GroupInvitePrefix = "torv3"

GroupInvitePrefix identifies a particular string as being a serialized group invite.

View Source 
const MaxGroupMessageLength = 1800

MaxGroupMessageLength is the maximum length of a message posted to a server group. TODO: Should this be per server?

View Source 
const MessageBaseSize float64 = 463

MessageBaseSize 2021.06 byte size of an *empty* message json serialized

View Source 
const OverlayChat = 1

OverlayChat is the canonical identifier for chat overlays

View Source 
const OverlayFileSharing = 200

OverlayFileSharing is the canonical identifier for the file sharing overlay

View Source 
const OverlayInviteContact = 100

OverlayInviteContact is the canonical identifier for the contact invite overlay

View Source 
const OverlayInviteGroup = 101

OverlayInviteGroup is the canonical identifier for the group invite overlay

Variables

This section is empty.

Functions

func CalculateContentHash added in v0.14.0 

func CalculateContentHash(author string, messageBody string) string

CalculateContentHash derives a hash using the author and the message body. It is intended to be globally referencable in the context of a single conversation

func EncryptMessageToGroup added in v0.14.0 

func EncryptMessageToGroup(message string, author primitives.Identity, group *Group, prevSig string) ([]byte, []byte, *groups.DecryptedGroupMessage, error)

EncryptMessageToGroup when given a message and a group, encrypts and signs the message under the group and profile

func GenerateRandomID added in v0.3.7 

func GenerateRandomID() string

GenerateRandomID generates a random 16 byte hex id code

func ValidateInvite added in v0.8.0 

func ValidateInvite(invite string) (*groups.GroupInvite, error)

ValidateInvite takes in a serialized invite and returns the invite structure if it is cryptographically valid and an error if it is not

Types

type AccessControl added in v0.14.0 

type AccessControl struct {
	Blocked bool // Any attempts from this handle to connect are blocked overrides all other settings

	// Basic Conversation Rights
	Read   bool // Allows a handle to access the conversation
	Append bool // Allows a handle to append new messages to the conversation

	AutoConnect        bool // Profile should automatically try to connect with peer
	ExchangeAttributes bool // Profile should automatically exchange attributes like Name, Profile Image, etc.

	// Extension Related Permissions
	ShareFiles   bool // Allows a handle to share files to a conversation
	RenderImages bool // Indicates that certain filetypes should be autodownloaded and rendered when shared by this contact
}

AccessControl is a type determining client assigned authorization to a peer for a given conversation

func DefaultP2PAccessControl added in v0.14.0 

func DefaultP2PAccessControl() AccessControl

DefaultP2PAccessControl defaults to a semi-trusted peer with no access to special extensions.

type AccessControlList added in v0.14.0 

type AccessControlList map[string]AccessControl

AccessControlList represents an access control list for a conversation. Mapping handles to conversation functions

func DeserializeAccessControlList added in v0.14.0 

func DeserializeAccessControlList(data []byte) (AccessControlList, error)

DeserializeAccessControlList takes in JSON and returns an AccessControlList

func (*AccessControlList) Serialize added in v0.14.0 

func (acl *AccessControlList) Serialize() []byte

Serialize transforms the ACL into json.

type Attributes added in v0.14.0 

type Attributes map[string]string

Attributes a type-driven encapsulation of an Attribute map.

func DeserializeAttributes added in v0.14.0 

func DeserializeAttributes(data []byte) Attributes

DeserializeAttributes converts a JSON struct into an Attributes map

func (*Attributes) Serialize added in v0.14.0 

func (a *Attributes) Serialize() []byte

Serialize transforms an Attributes map into a JSON struct

type Authorization added in v0.3.14 

type Authorization string

Authorization is a type determining client assigned authorization to a peer Deprecated - Only used for Importing legacy profile formats Still used in some APIs in UI but will be replaced prior to full deprecation 

const (
	// AuthUnknown is an initial state for a new unseen peer
	AuthUnknown Authorization = "unknown"
	// AuthApproved means the client has approved the peer, it can send messages to us, perform GetVals, etc
	AuthApproved Authorization = "approved"
	// AuthBlocked means the client has blocked the peer, it's messages and connections should be rejected
	AuthBlocked Authorization = "blocked"
)

type Conversation added in v0.14.0 

type Conversation struct {
	ID         int
	Handle     string
	Attributes Attributes
	ACL        AccessControlList

	// Deprecated, please use ACL for permissions related functions
	Accepted bool
}

Conversation encapsulates high-level information about a conversation, including the handle, any set attributes, the access control list associated with the message tree and the accepted status of the conversation (whether the user has consented into the conversation).

func (*Conversation) GetAttribute added in v0.14.0 

func (ci *Conversation) GetAttribute(scope attr.Scope, zone attr.Zone, key string) (string, bool)

GetAttribute is a helper function that fetches a conversation attribute by scope, zone and key

func (*Conversation) GetPeerAC added in v0.26.0 

func (ci *Conversation) GetPeerAC() AccessControl

GetPeerAC returns a suitable Access Control object for a the given peer conversation If this is called for a group conversation, this method will error and return a safe default AC.

func (*Conversation) IsGroup added in v0.14.0 

func (ci *Conversation) IsGroup() bool

IsGroup is a helper attribute that identifies whether a conversation is a legacy group

func (*Conversation) IsServer added in v0.14.0 

func (ci *Conversation) IsServer() bool

IsServer is a helper attribute that identifies whether a conversation is with a server

func (*Conversation) ServerSyncProgress added in v0.15.2 

func (ci *Conversation) ServerSyncProgress() float64

ServerSyncProgress is only valid during a server being in the AUTHENTICATED state and therefor in the syncing process it returns a double (0-1) representing the estimated progress of the syncing

type ConversationMessage added in v0.14.0 

type ConversationMessage struct {
	ID          int
	Body        string
	Attr        Attributes
	Signature   string
	ContentHash string
}

ConversationMessage bundles an instance of a conversation message row

type Error added in v0.4.1 

type Error string

Error models some common errors that need to be handled by applications that use Cwtch

func (Error) Error added in v0.4.1 

func (e Error) Error() string

Error is the error interface

type Experiments added in v0.19.0 

type Experiments struct {
	// contains filtered or unexported fields
}

Experiments are optional functionality that can be enabled/disabled by an application either completely or individually. examples of experiments include File Sharing, Profile Images and Groups.

func InitExperiments added in v0.19.0 

func InitExperiments(enabled bool, experiments map[string]bool) Experiments

InitExperiments encapsulates a set of experiments separate from their storage in GlobalSettings.

func (*Experiments) IsEnabled added in v0.19.0 

func (e *Experiments) IsEnabled(experiment string) bool

IsEnabled is a convenience function that takes in an experiment and returns true if it is enabled. Experiments are only enabled if both global experiments are turned on and if the specific experiment is also turned on. The one exception to this is experiments that have been promoted to default functionality which may be turned on even if experiments turned off globally. These experiments are defined by DefaultEnabledFunctionality.

type Group 

type Group struct {
	// GroupID is now derived from the GroupKey and the GroupServer
	GroupID     string
	GroupName   string
	GroupKey    [32]byte
	GroupServer string
	Attributes  map[string]string //legacy to not use
	Version     int
	Timeline    Timeline `json:"-"`
	LocalID     string
}

Group defines and encapsulates Cwtch's conception of group chat. Which are sessions tied to a server under a given group key. Each group has a set of Messages.

func NewGroup 

func NewGroup(server string) (*Group, error)

NewGroup initializes a new group associated with a given CwtchServer

func (*Group) AttemptDecryption added in v0.14.0 

func (g *Group) AttemptDecryption(ciphertext []byte, signature []byte) (bool, *groups.DecryptedGroupMessage)

AttemptDecryption takes a ciphertext and signature and attempts to decrypt it under known groups. If successful, adds the message to the group's timeline

func (*Group) CheckGroup added in v0.8.0 

func (g *Group) CheckGroup() bool

CheckGroup returns true only if the ID of the group is cryptographically valid.

func (*Group) DecryptMessage 

func (g *Group) DecryptMessage(ciphertext []byte) (bool, *groups.DecryptedGroupMessage)

DecryptMessage takes a ciphertext and returns true and the decrypted message if the cipher text can be successfully decrypted,else false.

func (*Group) EncryptMessage 

func (g *Group) EncryptMessage(message *groups.DecryptedGroupMessage) ([]byte, error)

EncryptMessage takes a message and encrypts the message under the group key.

func (*Group) Invite 

func (g *Group) Invite() (string, error)

Invite generates a invitation that can be sent to a cwtch peer

func (*Group) VerifyGroupMessage added in v0.14.0 

func (g *Group) VerifyGroupMessage(onion string, groupID string, message string, signature []byte) bool

VerifyGroupMessage confirms the authenticity of a message given an sender onion, message and signature. The goal of this function is 2-fold:

  1. We confirm that the sender referenced in the group text is the actual sender of the message (or at least knows the senders private key)
  2. Secondly, we confirm that the sender sent the message to a particular group id on a specific server (it doesn't matter if we actually received this message from the server or from a hybrid protocol, all that matters is that the sender and receivers agree that this message was intended for the group

The 2nd point is important as it prevents an attack documented in the original Cwtch paper (and later at https://docs.openprivacy.ca/cwtch-security-handbook/groups.html) in which a malicious profile sets up 2 groups on two different servers with the same key and then forwards messages between them to convince the parties in each group that they are actually in one big group (with the intent to later censor and/or selectively send messages to each group).

type Key added in v0.4.0 

type Key string

Key provides a wrapper for a generic public key identifier (could be an onion address, a zcash address etc.)

type KeyBundle added in v0.4.0 

type KeyBundle struct {
	Keys      map[KeyType]Key
	Signature []byte
}

KeyBundle manages a collection of related keys for various different services.

func DeserializeAndVerify added in v0.4.1 

func DeserializeAndVerify(bundle []byte) (*KeyBundle, error)

DeserializeAndVerify takes in a json formatted bundle and only returns a valid key bundle if it has been signed by the server.

func NewKeyBundle added in v0.4.1 

func NewKeyBundle() *KeyBundle

NewKeyBundle creates a new KeyBundle initialized with no keys.

func (*KeyBundle) AttributeBundle added in v0.4.0 

func (kb *KeyBundle) AttributeBundle() map[string]string

AttributeBundle returns a map that can be used as part of a peer attribute bundle

func (*KeyBundle) GetKey added in v0.4.0 

func (kb *KeyBundle) GetKey(keytype KeyType) (Key, error)

GetKey retrieves a key with a given type from the bundle

func (*KeyBundle) HasKeyType added in v0.4.0 

func (kb *KeyBundle) HasKeyType(keytype KeyType) bool

HasKeyType returns true if the bundle has a public key of a given type.

func (KeyBundle) Serialize added in v0.4.1 

func (kb KeyBundle) Serialize() []byte

Serialize produces a json encoded byte array.

func (*KeyBundle) Sign added in v0.4.1 

func (kb *KeyBundle) Sign(identity primitives.Identity)

Sign allows a server to authenticate a key bundle by signing it (this uses the tapir identity interface)

type KeyType added in v0.4.0 

type KeyType string

KeyType provides a wrapper for a generic public key type identifier (could be an onion address, a zcash address etc.)

type LocallyIndexedMessage added in v0.9.1 

type LocallyIndexedMessage struct {
	Message
	LocalIndex int
}

LocallyIndexedMessage is a type wrapper around a Message and a TimeLine Index that is local to this instance of the timeline.

type Message 

type Message struct {
	Timestamp          time.Time
	Received           time.Time
	PeerID             string
	Message            string
	Signature          []byte
	PreviousMessageSig []byte
	ReceivedByServer   bool   // messages sent to a server
	Acknowledged       bool   // peer to peer
	Error              string `json:",omitempty"`
	// Application specific flags, useful for storing small amounts of metadata
	Flags uint64
}

Message is a local representation of a given message sent over a group chat channel.

type MessageWrapper added in v0.11.0 

type MessageWrapper struct {
	Overlay int    `json:"o"`
	Data    string `json:"d"`

	// when the data was assembled
	SendTime *time.Time `json:"s,omitempty"`

	// when the data was transmitted (by protocol engine e.g. over Tor)
	TransitTime *time.Time `json:"t,omitempty"`

	// when the data was received
	RecvTime *time.Time `json:"r,omitempty"`
}

MessageWrapper is the canonical Cwtch overlay wrapper

func DeserializeMessage added in v0.27.0 

func DeserializeMessage(message string) (*MessageWrapper, error)

func (MessageWrapper) Channel added in v0.27.0 

func (mw MessageWrapper) Channel() int

Channel is defined as being the last 3 bits of the overlay id Channel 0 is reserved for the main conversation Channel 2 is reserved for conversation admin (managed groups) Channel 7 is reserved for streams (no ack, no store)

func (MessageWrapper) IsStream added in v0.27.0 

func (mw MessageWrapper) IsStream() bool

If Overlay is a Stream Message it should not be ackd, or stored.

type Profile 

type Profile struct {
	PublicProfile
	Contacts          map[string]*PublicProfile
	Ed25519PrivateKey ed25519.PrivateKey
	Groups            map[string]*Group
}

Profile encapsulates all the attributes necessary to be a Cwtch Peer. Deprecated - Only used for Importing legacy profile formats

func (*Profile) GetCopy 

func (p *Profile) GetCopy(timeline bool) *Profile

GetCopy returns a full deep copy of the Profile struct and its members (timeline inclusion control by arg)

type PublicProfile 

type PublicProfile struct {
	Name              string
	Ed25519PublicKey  ed25519.PublicKey
	Authorization     Authorization
	DeprecatedBlocked bool `json:"Blocked"`
	Onion             string
	Attributes        map[string]string
	Timeline          Timeline `json:"-"`
	LocalID           string   // used by storage engine
	State             string   `json:"-"`

	UnacknowledgedMessages map[string]int
	// contains filtered or unexported fields
}

PublicProfile is a local copy of a CwtchIdentity Deprecated - Only used for Importing legacy profile formats

type Timeline 

type Timeline struct {
	Messages      []Message
	SignedGroupID []byte
	// contains filtered or unexported fields
}

Timeline encapsulates a collection of ordered Messages, and a mechanism to access them in a threadsafe manner.

func (*Timeline) GetCopy 

func (t *Timeline) GetCopy() *Timeline

GetCopy returns a duplicate of the Timeline

func (*Timeline) GetMessages 

func (t *Timeline) GetMessages() []Message

GetMessages returns a copy of the entire timeline

func (*Timeline) GetMessagesByHash added in v0.9.1 

func (t *Timeline) GetMessagesByHash(contentHash string) ([]LocallyIndexedMessage, error)

GetMessagesByHash attempts to find messages that match the given content hash in the timeline. If successful it returns a list of messages as well as their local index , on failure it returns an error. We return a list of messages because content hashes are not guaranteed to be unique from a given Peer. This allows us to do things like: ensure that reply-to and quotes reference the last seen message from the message they are quoted in or detect duplicate messages from a peer.

func (*Timeline) Insert 

func (t *Timeline) Insert(mi *Message) int

Insert a message into the timeline in a thread safe way.

func (*Timeline) Len 

func (t *Timeline) Len() int

Len gets the length of the timeline

func (*Timeline) Less 

func (t *Timeline) Less(i, j int) bool

Less checks 2 Messages (i and j) in the timeline and returns true if i occurred before j, else false

func (*Timeline) SetMessages 

func (t *Timeline) SetMessages(messages []Message)

SetMessages sets the Messages of this timeline. Only to be used in loading/initialization

func (*Timeline) SetSendError added in v0.13.0 

func (t *Timeline) SetSendError(sig []byte, e string) bool

SetSendError marks a message has having some kind of application specific error. Note: The message here is indexed by signature.

func (*Timeline) Sort 

func (t *Timeline) Sort()

Sort sorts the timeline in a canonical order.

func (*Timeline) Swap 

func (t *Timeline) Swap(i, j int)

Swap swaps 2 Messages on the timeline.

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