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/*
* Off-the-Record Messaging library
* Copyright (C) 2004-2015 Ian Goldberg, 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
*/
/* system headers */
#include <stdio.h>
#include <stdlib.h>
/* libgcrypt headers */
#include <gcrypt.h>
/* libotr headers */
#include "instag.h"
#include "userstate.h"
/* Forget the given instag. */
void otrl_instag_forget(OtrlInsTag* instag) {
if (!instag) return;
if (instag->accountname) free(instag->accountname);
if (instag->protocol) free(instag->protocol);
/* Re-link the list */
*(instag->tous) = instag->next;
if (instag->next) {
instag->next->tous = instag->tous;
}
free(instag);
}
/* Forget all instags in a given OtrlUserState. */
void otrl_instag_forget_all(OtrlUserState us) {
while(us->instag_root) {
otrl_instag_forget(us->instag_root);
}
}
/* Fetch the instance tag from the given OtrlUserState associated with
* the given account */
OtrlInsTag * otrl_instag_find(OtrlUserState us, const char *accountname,
const char *protocol)
{
OtrlInsTag *p;
for(p=us->instag_root; p; p=p->next) {
if (!strcmp(p->accountname, accountname) &&
!strcmp(p->protocol, protocol)) {
return p;
}
}
return NULL;
}
/* Read our instance tag from a file on disk into the given
* OtrlUserState. */
gcry_error_t otrl_instag_read(OtrlUserState us, const char *filename)
{
gcry_error_t err;
FILE *instf;
/* Open the instance tag file. */
instf = fopen(filename, "rb");
if (!instf) {
return gcry_error_from_errno(errno);
}
err = otrl_instag_read_FILEp(us, instf);
fclose(instf);
return err;
}
/* Read our instance tag from a file on disk into the given
* OtrlUserState. The FILE* must be open for reading. */
gcry_error_t otrl_instag_read_FILEp(OtrlUserState us, FILE *instf)
{
if (!instf) return gcry_error(GPG_ERR_NO_ERROR);
OtrlInsTag *p;
char storeline[1000];
size_t maxsize = sizeof(storeline);
while(fgets(storeline, maxsize, instf)) {
char *prevpos;
char *pos;
unsigned int instag = 0;
p = malloc(sizeof(*p));
if (!p) {
return gcry_error(GPG_ERR_ENOMEM);
}
/* Parse the line, which should be of the form:
* accountname\tprotocol\t40_hex_nybbles\n */
prevpos = storeline;
pos = strchr(prevpos, '\t');
if (!pos) {
free(p);
continue;
}
*pos = '\0';
pos++;
p->accountname = malloc(pos - prevpos);
if (!(p->accountname)) {
free(p);
return gcry_error(GPG_ERR_ENOMEM);
}
memmove(p->accountname, prevpos, pos - prevpos);
prevpos = pos;
pos = strchr(prevpos, '\t');
if (!pos) {
free(p->accountname);
free(p);
continue;
}
*pos = '\0';
pos++;
p->protocol = malloc(pos - prevpos);
if (!(p->protocol)) {
free(p->accountname);
free(p);
return gcry_error(GPG_ERR_ENOMEM);
}
memmove(p->protocol, prevpos, pos - prevpos);
prevpos = pos;
pos = strchr(prevpos, '\r');
if (!pos) pos = strchr(prevpos, '\n');
if (!pos) {
free(p->accountname);
free(p->protocol);
free(p);
continue;
}
*pos = '\0';
pos++;
/* hex str of length 8 */
if (strlen(prevpos) != 8) {
free(p->accountname);
free(p->protocol);
free(p);
continue;
}
sscanf(prevpos, "%08x", &instag);
if (instag < OTRL_MIN_VALID_INSTAG) {
free(p->accountname);
free(p->protocol);
free(p);
continue;
}
p->instag = instag;
/* Link it up */
p->next = us->instag_root;
if (p->next) {
p->next->tous = &(p->next);
}
p->tous = &(us->instag_root);
us->instag_root = p;
}
return gcry_error(GPG_ERR_NO_ERROR);
}
/* Generate a new instance tag for the given account and write to file */
gcry_error_t otrl_instag_generate(OtrlUserState us, const char *filename,
const char *accountname, const char *protocol)
{
gcry_error_t err;
FILE *instf;
/* Open the instance tag file. */
instf = fopen(filename, "wb");
if (!instf) {
return gcry_error_from_errno(errno);
}
err = otrl_instag_generate_FILEp(us, instf, accountname, protocol);
fclose(instf);
return err;
}
/* Return a new valid instance tag */
otrl_instag_t otrl_instag_get_new()
{
otrl_instag_t result = 0;
while(result < OTRL_MIN_VALID_INSTAG) {
otrl_instag_t * instag = (otrl_instag_t *)gcry_random_bytes(
sizeof(otrl_instag_t), GCRY_STRONG_RANDOM);
result = *instag;
gcry_free(instag);
}
return result;
}
/* Generate a new instance tag for the given account and write to file
* The FILE* must be open for writing. */
gcry_error_t otrl_instag_generate_FILEp(OtrlUserState us, FILE *instf,
const char *accountname, const char *protocol)
{
OtrlInsTag *p;
if (!accountname || !protocol) return gcry_error(GPG_ERR_NO_ERROR);
p = (OtrlInsTag *)malloc(sizeof(OtrlInsTag));
p->accountname = strdup(accountname);
p->protocol = strdup(protocol);
p->instag = otrl_instag_get_new();
/* Add to our list in OtrlUserState */
p->next = us->instag_root;
if (p->next) {
p->next->tous = &(p->next);
}
p->tous = &(us->instag_root);
us->instag_root = p;
otrl_instag_write_FILEp(us, instf);
return gcry_error(GPG_ERR_NO_ERROR);
}
/* Write our instance tags to a file on disk. */
gcry_error_t otrl_instag_write(OtrlUserState us, const char *filename)
{
gcry_error_t err;
FILE *instf;
/* Open the instance tag file. */
instf = fopen(filename, "wb");
if (!instf) {
return gcry_error_from_errno(errno);
}
err = otrl_instag_write_FILEp(us, instf);
fclose(instf);
return err;
}
/* Write our instance tags to a file on disk.
* The FILE* must be open for writing. */
gcry_error_t otrl_instag_write_FILEp(OtrlUserState us, FILE *instf)
{
OtrlInsTag *p;
/* This line should be ignored when read back in, since there are no
tabs. */
fprintf(instf, "# WARNING! You shouldn't copy this file to another"
" computer. It is unnecessary and can cause problems.\n");
for(p=us->instag_root; p; p=p->next) {
fprintf(instf, "%s\t%s\t%08x\n", p->accountname, p->protocol,
p->instag);
}
return gcry_error(GPG_ERR_NO_ERROR);
}