1 files changed, 126 insertions, 0 deletions

diff --git a/swaylock/password.c b/swaylock/password.c
new file mode 100644
index 00000000..1839f991
--- /dev/null
+++ b/swaylock/password.c
@@ -0,0 +1,126 @@
+#include <assert.h>
+#include <pwd.h>
+#include <security/pam_appl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <wlr/util/log.h>
+#include <xkbcommon/xkbcommon.h>
+#include "swaylock/swaylock.h"
+#include "swaylock/seat.h"
+#include "unicode.h"
+
+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 = pw->buffer;
+                        break;
+                case PAM_ERROR_MSG:
+                case PAM_TEXT_INFO:
+                        break;
+                }
+        }
+        return PAM_SUCCESS;
+}
+
+static 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(L_ERROR, "PAM returned error %d", pam_err);
+        }
+        if ((pam_err = pam_authenticate(local_auth_handle, 0)) != PAM_SUCCESS) {
+                wlr_log(L_ERROR, "pam_authenticate failed");
+                goto fail;
+        }
+        if ((pam_err = pam_end(local_auth_handle, pam_err)) != PAM_SUCCESS) {
+                wlr_log(L_ERROR, "pam_end failed");
+                goto fail;
+        }
+        // PAM frees this
+        pw->buffer = NULL;
+        pw->len = pw->size = 0;
+        return true;
+fail:
+        // PAM frees this
+        pw->buffer = NULL;
+        pw->len = pw->size = 0;
+        return false;
+}
+
+static bool backspace(struct swaylock_password *pw) {
+        if (pw->len != 0) {
+                pw->buffer[--pw->len] = 0;
+                return true;
+        }
+        return false;
+}
+
+static void append_ch(struct swaylock_password *pw, uint32_t codepoint) {
+        if (!pw->buffer) {
+                pw->size = 8;
+                if (!(pw->buffer = malloc(pw->size))) {
+                        // TODO: Display error
+                        return;
+                }
+                pw->buffer[0] = 0;
+        }
+        size_t utf8_size = utf8_chsize(codepoint);
+        if (pw->len + utf8_size + 1 >= pw->size) {
+                size_t size = pw->size * 2;
+                char *buffer = realloc(pw->buffer, size);
+                if (!buffer) {
+                        // TODO: Display error
+                        return;
+                }
+                pw->size = size;
+                pw->buffer = buffer;
+        }
+        utf8_encode(&pw->buffer[pw->len], codepoint);
+        pw->buffer[pw->len + utf8_size] = 0;
+        pw->len += utf8_size;
+}
+
+void swaylock_handle_key(struct swaylock_state *state,
+                xkb_keysym_t keysym, uint32_t codepoint) {
+        switch (keysym) {
+                case XKB_KEY_KP_Enter: /* fallthrough */
+                case XKB_KEY_Return:
+                        state->auth_state = AUTH_STATE_VALIDATING;
+                        render_frames(state);
+                        wl_display_roundtrip(state->display);
+                        if (attempt_password(&state->password)) {
+                                state->run_display = false;
+                                break;
+                        }
+                        state->auth_state = AUTH_STATE_INVALID;
+                        render_frames(state);
+                        break;
+                case XKB_KEY_BackSpace:
+                        if (backspace(&state->password)) {
+                                state->auth_state = AUTH_STATE_BACKSPACE;
+                                render_frames(state);
+                        }
+                        break;
+                default:
+                        if (codepoint) {
+                                append_ch(&state->password, codepoint);
+                                state->auth_state = AUTH_STATE_INPUT;
+                                render_frames(state);
+                        }
+                        break;
+        }
+}