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;
+	}
+}