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/*
* Copyright (c) 2011-2014 Yubico AB
* All rights reserved.
*
* Author : Fredrik Thulin <fredrik@yubico.com>
*
* Based on ykchalresp.c from yubikey-personalization.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <string.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <ykpers.h>
#include "util.h"
#define ACTION_ADD_HMAC_CHALRESP "add_hmac_chalresp"
#define ACTION_MAX_LEN 1024
const char *usage =
"Usage: ykpamcfg [options]\n"
"\n"
"Options :\n"
"\n"
"\t-1 Send challenge to slot 1. This is the default.\n"
"\t-2 Send challenge to slot 2.\n"
"\t-A action What to do.\n"
"\t-p path Specify an output path for the challenge file.\n"
"\t-i iters Number of iterations to use for pbkdf2 (defaults to 10000)\n"
"\n"
"\t-v Increase verbosity\n"
"\t-V Show version and exit\n"
"\t-h Show help (this text) and exit\n"
"\n"
"Actions :\n"
"\n"
"\t" ACTION_ADD_HMAC_CHALRESP "\tAdds a challenge-response state file for a connected YubiKey (default)\n"
"\n"
"\n"
;
const char *optstring = "12A:p:i:vVh";
static void
report_yk_error(void)
{
if (ykp_errno)
fprintf(stderr, "Yubikey personalization error: %s\n",
ykp_strerror(ykp_errno));
if (yk_errno) {
if (yk_errno == YK_EUSBERR) {
fprintf(stderr, "USB error: %s\n",
yk_usb_strerror());
} else {
fprintf(stderr, "Yubikey core error: %s\n",
yk_strerror(yk_errno));
}
}
}
static int
parse_args(int argc, char **argv,
int *slot, bool *verbose,
char **action, char **output_dir,
unsigned int *iterations)
{
int c;
while((c = getopt(argc, argv, optstring)) != -1) {
switch (c) {
case '1':
*slot = 1;
break;
case '2':
*slot = 2;
break;
case 'A':
strncpy(*action, optarg, ACTION_MAX_LEN);
break;
case 'p':
*output_dir = optarg;
break;
case 'i':
{
char *endptr;
*iterations = strtoul(optarg, &endptr, 10);
if(*endptr != '\0') {
fprintf(stderr, "iterations must be numeric, %s isn't.\n", optarg);
exit(1);
}
}
break;
case 'v':
*verbose = true;
break;
case 'V':
printf("%s\n", VERSION);
exit(0);
case 'h':
default:
fputs(usage, stderr);
exit(0);
}
}
return 1;
}
static int
do_add_hmac_chalresp(YK_KEY *yk, uint8_t slot, bool verbose, char *output_dir, unsigned int iterations, int *exit_code)
{
char buf[CR_RESPONSE_SIZE + 16];
CR_STATE state;
int ret = 0;
unsigned int response_len;
char *fn;
struct passwd *p;
FILE *f = NULL;
struct stat st;
state.iterations = iterations;
state.slot = slot;
*exit_code = 1;
p = getpwuid (getuid ());
if (! p) {
fprintf (stderr, "Who am I???");
goto out;
}
/*
* Create default output directory for the user
*/
if (!output_dir){
char fullpath[256];
snprintf(fullpath, 256,"%s/.yubico",p->pw_dir);
//check if directory exists
if (stat(fullpath,&st)!=0 ){
if(mkdir(fullpath, S_IRWXU)==-1){
fprintf(stderr, "Failed creating directory '%s' :%s\n",
fullpath, strerror(errno));
}
if(verbose){
printf("Directory %s created successfully.\n", fullpath);
}
}
else{
if(!S_ISDIR(st.st_mode)){
fprintf(stderr, "Destination %s already exist and is not a directory.\n",
fullpath);
goto out;
}
}
}
if (! get_user_challenge_file(yk, output_dir, p, &fn, stdout)) {
fprintf (stderr, "Failed getting chalresp state filename\n");
goto out;
}
if (stat(fn, &st) == 0) {
fprintf(stderr, "File %s already exists, refusing to overwrite.\n", fn);
goto out;
}
if (generate_random(state.challenge, CR_CHALLENGE_SIZE)) {
fprintf (stderr, "FAILED getting %i bytes of random data\n", CR_CHALLENGE_SIZE);
goto out;
}
state.challenge_len = CR_CHALLENGE_SIZE;
if (! challenge_response(yk, state.slot, state.challenge, CR_CHALLENGE_SIZE,
true, true, verbose,
buf, sizeof(buf), &response_len))
goto out;
/* Make sure we get different responses for different challenges
There is a firmware bug in YubiKey 2.2 that makes it issue same
response for all challenges unless HMAC_LT64 is set. */
{
char buf2[CR_RESPONSE_SIZE + 16];
char challenge[CR_CHALLENGE_SIZE];
if (generate_random(challenge, CR_CHALLENGE_SIZE)) {
fprintf (stderr, "FAILED getting %i bytes of random data\n", CR_CHALLENGE_SIZE);
goto out;
}
if (! challenge_response(yk, state.slot, challenge, CR_CHALLENGE_SIZE,
true, true, verbose,
buf2, sizeof(buf2), &response_len))
goto out;
if (memcmp(buf, buf2, response_len) == 0) {
fprintf (stderr, "FAILED YubiKey is outputting the same response for different challenges."
"Make sure you configure the key with the option HMAC_LT64.\n");
goto out;
}
}
if (response_len > sizeof (state.response)) {
fprintf (stderr, "Got too long response ??? (%u/%lu)", response_len, (unsigned long) sizeof(state.response));
goto out;
}
memcpy (state.response, buf, response_len);
state.response_len = response_len;
umask(077);
f = fopen (fn, "w");
if (! f) {
fprintf (stderr, "Failed opening '%s' for writing : %s\n", fn, strerror (errno));
goto out;
}
if (! write_chalresp_state (f, &state))
goto out;
printf ("Stored initial challenge and expected response in '%s'.\n", fn);
*exit_code = 0;
ret = 1;
out:
if (f)
fclose (f);
return ret;
}
int
main(int argc, char **argv)
{
YK_KEY *yk = NULL;
bool error = true;
int exit_code = 0;
/* Options */
bool verbose = false;
char action[ACTION_MAX_LEN];
char *ptr = action;
char *output_dir = NULL;
int slot = 1;
unsigned int iterations = CR_DEFAULT_ITERATIONS;
ykp_errno = 0;
yk_errno = 0;
strcpy (action, ACTION_ADD_HMAC_CHALRESP);
if (! parse_args(argc, argv,
&slot, &verbose,
&ptr, &output_dir,
&iterations))
goto err;
exit_code = 1;
if (! strncmp(action, ACTION_ADD_HMAC_CHALRESP, ACTION_MAX_LEN)) {
/*
* Set up challenge-response login authentication
*/
if (! init_yubikey (&yk))
goto err;
if (! check_firmware_version(yk, verbose, false, stdout))
goto err;
if (! do_add_hmac_chalresp (yk, slot, verbose, output_dir, iterations, &exit_code))
goto err;
} else {
fprintf (stderr, "Unknown action '%s'\n", action);
goto err;
}
exit_code = 0;
error = false;
err:
if (error || exit_code != 0) {
report_yk_error ();
}
if (yk && !yk_close_key (yk)) {
report_yk_error ();
exit_code = 2;
}
if (!yk_release ()) {
report_yk_error ();
exit_code = 2;
}
exit (exit_code);
}