mirror of
https://github.com/NickHu/sway
synced 2024-11-16 19:49:56 +01:00
c977349120
This involves setuid'ing swaylock, which then forks and drops perms on the parent process. The child process remains root and listens on a pipe for requests to validate passwords against /etc/shadow.
62 lines
1.8 KiB
C
62 lines
1.8 KiB
C
#define _XOPEN_SOURCE 500
|
|
#include <pwd.h>
|
|
#include <security/pam_appl.h>
|
|
#include <stdbool.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <wlr/util/log.h>
|
|
#include "swaylock/swaylock.h"
|
|
|
|
void initialize_pw_backend(void) {
|
|
// TODO: only call pam_start once. keep the same handle the whole time
|
|
}
|
|
|
|
static int function_conversation(int num_msg, const struct pam_message **msg,
|
|
struct pam_response **resp, void *data) {
|
|
struct swaylock_password *pw = data;
|
|
/* PAM expects an array of responses, one for each message */
|
|
struct pam_response *pam_reply = calloc(
|
|
num_msg, sizeof(struct pam_response));
|
|
*resp = pam_reply;
|
|
for (int i = 0; i < num_msg; ++i) {
|
|
switch (msg[i]->msg_style) {
|
|
case PAM_PROMPT_ECHO_OFF:
|
|
case PAM_PROMPT_ECHO_ON:
|
|
pam_reply[i].resp = strdup(pw->buffer); // PAM clears and frees this
|
|
break;
|
|
case PAM_ERROR_MSG:
|
|
case PAM_TEXT_INFO:
|
|
break;
|
|
}
|
|
}
|
|
return PAM_SUCCESS;
|
|
}
|
|
|
|
bool attempt_password(struct swaylock_password *pw) {
|
|
struct passwd *passwd = getpwuid(getuid());
|
|
char *username = passwd->pw_name;
|
|
const struct pam_conv local_conversation = {
|
|
function_conversation, pw
|
|
};
|
|
pam_handle_t *local_auth_handle = NULL;
|
|
int pam_err;
|
|
if ((pam_err = pam_start("swaylock", username,
|
|
&local_conversation, &local_auth_handle)) != PAM_SUCCESS) {
|
|
wlr_log(WLR_ERROR, "PAM returned error %d", pam_err);
|
|
}
|
|
if ((pam_err = pam_authenticate(local_auth_handle, 0)) != PAM_SUCCESS) {
|
|
wlr_log(WLR_ERROR, "pam_authenticate failed");
|
|
goto fail;
|
|
}
|
|
// TODO: only call pam_end once we succeed at authing. refresh tokens beforehand
|
|
if ((pam_err = pam_end(local_auth_handle, pam_err)) != PAM_SUCCESS) {
|
|
wlr_log(WLR_ERROR, "pam_end failed");
|
|
goto fail;
|
|
}
|
|
clear_password_buffer(pw);
|
|
return true;
|
|
fail:
|
|
clear_password_buffer(pw);
|
|
return false;
|
|
}
|