WPS: Added helper functions for generating and validating PINs

This commit is contained in:
Jouni Malinen 2008-11-29 14:02:09 +02:00
parent b01c18a8ef
commit e05716d0b0
2 changed files with 55 additions and 0 deletions

View file

@ -133,4 +133,8 @@ int wps_registrar_button_pushed(struct wps_registrar *reg);
void wps_registrar_probe_req_rx(struct wps_registrar *reg, const u8 *addr, void wps_registrar_probe_req_rx(struct wps_registrar *reg, const u8 *addr,
const struct wpabuf *wps_data); const struct wpabuf *wps_data);
unsigned int wps_pin_checksum(unsigned int pin);
unsigned int wps_pin_valid(unsigned int pin);
unsigned int wps_generate_pin(void);
#endif /* WPS_H */ #endif /* WPS_H */

View file

@ -247,3 +247,54 @@ struct wpabuf * wps_decrypt_encr_settings(struct wps_data *wps, const u8 *encr,
return decrypted; return decrypted;
} }
/**
* wps_pin_checksum - Compute PIN checksum
* @pin: Seven digit PIN (i.e., eight digit PIN without the checksum digit)
* Returns: Checksum digit
*/
unsigned int wps_pin_checksum(unsigned int pin)
{
unsigned int accum = 0;
while (pin) {
accum += 3 * (pin % 10);
pin /= 10;
accum += pin % 10;
pin /= 10;
}
return (10 - accum % 10) % 10;
}
/**
* wps_pin_valid - Check whether a PIN has a valid checksum
* @pin: Eight digit PIN (i.e., including the checksum digit)
* Returns: 1 if checksum digit is valid, or 0 if not
*/
unsigned int wps_pin_valid(unsigned int pin)
{
return wps_pin_checksum(pin / 10) == (pin % 10);
}
/**
* wps_generate_pin - Generate a random PIN
* Returns: Eight digit PIN (i.e., including the checksum digit)
*/
unsigned int wps_generate_pin(void)
{
unsigned int val;
/* Generate seven random digits for the PIN */
if (os_get_random((unsigned char *) &val, sizeof(val)) < 0) {
struct os_time now;
os_get_time(&now);
val = os_random() ^ now.sec ^ now.usec;
}
val %= 10000000;
/* Append checksum digit */
return val * 10 + wps_pin_checksum(val);
}