/** Generate a random challenge (ascii chars 0-9)
*
* @note This is really cryptocard-specific (automatic ASCII conversion
* @note and null termination).
*
* @param[out] challenge Buffer to write random string to.
* @param[in] len Number of random bytes to write to buffer.
*/
void otp_async_challenge(char challenge[OTP_MAX_CHALLENGE_LEN + 1],
size_t len)
{
uint8_t rawchallenge[OTP_MAX_CHALLENGE_LEN];
unsigned int i;
otp_get_random(rawchallenge, len);
/* Convert the raw bytes to ASCII decimal. */
for (i = 0; i < len; ++i) {
challenge[i] = '0' + rawchallenge[i] % 10;
}
challenge[len] = '\0';
}
/*
* Per-instance initialization
*/
static int mod_instantiate(CONF_SECTION *conf, void *instance)
{
rlm_otp_t *inst = instance;
/* Onetime initialization. */
if (!ninstance) {
/* Generate a random key, used to protect the State attribute. */
otp_get_random(inst->hmac_key, sizeof(inst->hmac_key));
/* Initialize the passcode encoding/checking functions. */
otp_pwe_init();
/*
* Don't do this again.
* Only the main thread instantiates and detaches instances,
* so this does not need mutex protection.
*/
ninstance++;
}
/* Verify ranges for those vars that are limited. */
if ((inst->challenge_len < 5) ||
(inst->challenge_len > OTP_MAX_CHALLENGE_LEN)) {
inst->challenge_len = 6;
WDEBUG("invalid challenge_length %d, "
"range 5-%d, using default of 6",
inst->challenge_len, OTP_MAX_CHALLENGE_LEN);
}
if (!inst->allow_sync && !inst->allow_async) {
cf_log_err_cs(conf, "at least one of {allow_async, "
"allow_sync} must be set");
return -1;
}
if ((inst->mschapv2_mppe_policy > 2) ||
(inst->mschapv2_mppe_policy < 0)) {
inst->mschapv2_mppe_policy = 2;
WDEBUG("Invalid value for mschapv2_mppe, "
"using default of 2");
}
if ((inst->mschapv2_mppe_types > 2) || (inst->mschapv2_mppe_types < 0)) {
inst->mschapv2_mppe_types = 2;
WDEBUG("Invalid value for "
"mschapv2_mppe_bits, using default of 2");
}
if ((inst->mschap_mppe_policy > 2) || (inst->mschap_mppe_policy < 0)) {
inst->mschap_mppe_policy = 2;
WDEBUG("Invalid value for mschap_mppe, "
"using default of 2");
}
if (inst->mschap_mppe_types != 2) {
inst->mschap_mppe_types = 2;
WDEBUG("Invalid value for "
"mschap_mppe_bits, using default of 2");
}
/* set the instance name (for use with authorize()) */
inst->name = cf_section_name2(conf);
if (!inst->name) inst->name = cf_section_name1(conf);
return 0;
}
