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/*
* Off-the-Record Messaging library
* Copyright (C) 2004-2014 Ian Goldberg, David Goulet, Rob Smits,
* Chris Alexander, Willy Lew, Lisa Du,
* Nikita Borisov
* <otr@cypherpunks.ca>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of version 2.1 of the GNU Lesser General
* Public License as published by the Free Software Foundation.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __CONTEXT_H__
#define __CONTEXT_H__
#include "context_priv.h"
#include <gcrypt.h>
#include "dh.h"
#include "auth.h"
#include "sm.h"
typedef struct context ConnContext; /* Forward declare */
#include "instag.h"
typedef enum {
OTRL_MSGSTATE_PLAINTEXT, /* Not yet started an encrypted
conversation */
OTRL_MSGSTATE_ENCRYPTED, /* Currently in an encrypted
conversation */
OTRL_MSGSTATE_FINISHED /* The remote side has sent us a
notification that he has ended
his end of the encrypted
conversation; prevent any
further messages from being
sent to him. */
} OtrlMessageState;
typedef struct s_fingerprint {
struct s_fingerprint *next; /* The next fingerprint in the list */
struct s_fingerprint **tous; /* A pointer to the pointer to us */
unsigned char *fingerprint; /* The fingerprint, or NULL */
struct context *context; /* The context to which we belong */
char *trust; /* The trust level of the fingerprint */
} Fingerprint;
struct context {
struct context * next; /* Linked list pointer */
struct context ** tous; /* A pointer to the pointer to us */
/* Context information that is meant for internal use */
ConnContextPriv *context_priv;
/* Context information that is meant for application use */
char * username; /* The user this context is for */
char * accountname; /* The username is relative to
this account... */
char * protocol; /* ... and this protocol */
struct context *m_context; /* If this is a child context, this
field will point to the master
context. Otherwise it will point to
itself. */
struct context *recent_rcvd_child; /* If this is a master context, this
points to the child context that
has received a message most recently.
By default, it will point to the
master context. In child contexts
this field is NULL. */
struct context *recent_sent_child; /* Similar to above, but it points to
the child who has sent most
recently. */
struct context *recent_child; /* Similar to above, but will point to
the most recent of recent_rcvd_child
and recent_sent_child */
otrl_instag_t our_instance; /* Our instance tag for this computer*/
otrl_instag_t their_instance; /* The user's instance tag */
OtrlMessageState msgstate; /* The state of message disposition
with this user */
OtrlAuthInfo auth; /* The state of ongoing
authentication with this user */
Fingerprint fingerprint_root; /* The root of a linked list of
Fingerprints entries. This list will
only be populated in master contexts.
For child contexts,
fingerprint_root.next will always
point to NULL. */
Fingerprint *active_fingerprint; /* Which fingerprint is in use now?
A pointer into the above list */
unsigned char sessionid[20]; /* The sessionid and bold half */
size_t sessionid_len; /* determined when this private */
OtrlSessionIdHalf sessionid_half; /* connection was established. */
unsigned int protocol_version; /* The version of OTR in use */
enum {
OFFER_NOT,
OFFER_SENT,
OFFER_REJECTED,
OFFER_ACCEPTED
} otr_offer; /* Has this correspondent repsponded to our
OTR offers? */
/* Application data to be associated with this context */
void *app_data;
/* A function to free the above data when we forget this context */
void (*app_data_free)(void *);
OtrlSMState *smstate; /* The state of the current
socialist millionaires exchange */
};
#include "userstate.h"
/* Look up a connection context by name/account/protocol/instance from the
* given OtrlUserState. If add_if_missing is true, allocate and return a
* new context if one does not currently exist. In that event, call
* add_app_data(data, context) so that app_data and app_data_free can be
* filled in by the application, and set *addedp to 1.
* In the 'their_instance' field note that you can also specify a 'meta-
* instance' value such as OTRL_INSTAG_MASTER, OTRL_INSTAL_RECENT,
* OTRL_INSTAG_RECENT_RECEIVED and OTRL_INSTAG_RECENT_SENT. */
ConnContext * otrl_context_find(OtrlUserState us, const char *user,
const char *accountname, const char *protocol,
otrl_instag_t their_instance, int add_if_missing, int *addedp,
void (*add_app_data)(void *data, ConnContext *context), void *data);
/* Return true iff the given fingerprint is marked as trusted. */
int otrl_context_is_fingerprint_trusted(Fingerprint *fprint);
/* This method gets called after sending or receiving a message, to
* update the master context's "recent context" pointers. */
void otrl_context_update_recent_child(ConnContext *context,
unsigned int sent_msg);
/* Find a fingerprint in a given context, perhaps adding it if not
* present. */
Fingerprint *otrl_context_find_fingerprint(ConnContext *context,
unsigned char fingerprint[20], int add_if_missing, int *addedp);
/* Set the trust level for a given fingerprint */
void otrl_context_set_trust(Fingerprint *fprint, const char *trust);
/* Force a context into the OTRL_MSGSTATE_FINISHED state. */
void otrl_context_force_finished(ConnContext *context);
/* Force a context into the OTRL_MSGSTATE_PLAINTEXT state. */
void otrl_context_force_plaintext(ConnContext *context);
/* Forget a fingerprint (so long as it's not the active one. If it's a
* fingerprint_root, forget the whole context (as long as
* and_maybe_context is set, and it's PLAINTEXT). Also, if it's not
* the fingerprint_root, but it's the only fingerprint, and we're
* PLAINTEXT, forget the whole context if and_maybe_context is set. */
void otrl_context_forget_fingerprint(Fingerprint *fprint,
int and_maybe_context);
/* Forget a whole context, so long as it's PLAINTEXT. If a context has child
* instances, don't remove this instance unless children are also all in
* PLAINTEXT state. In this case, the children will also be removed.
* Returns 0 on success, 1 on failure. */
int otrl_context_forget(ConnContext *context);
/* Forget all the contexts in a given OtrlUserState. */
void otrl_context_forget_all(OtrlUserState us);
/* Find requested recent instance */
ConnContext * otrl_context_find_recent_instance(ConnContext * context,
otrl_instag_t recent_instag);
/* Find the instance of this context that has the best security level, and for
* which we have most recently received a message from. Note that most recent
* in this case is limited to a one-second resolution. */
ConnContext * otrl_context_find_recent_secure_instance(ConnContext * context);
#endif
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