1 files changed, 116 insertions, 0 deletions
diff --git a/src/pinentry/util.cpp b/src/pinentry/util.cpp
new file mode 100644
index 00000000..f1bac4ba
--- /dev/null
+++ b/src/pinentry/util.cpp
@@ -0,0 +1,116 @@
+/* Quintuple Agent
+ * Copyright (C) 1999 Robert Bihlmeyer <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define _GNU_SOURCE 1
+
+#include <unistd.h>
+#ifndef WINDOWS
+# include <errno.h>
+#endif
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include "util.h"
+
+#ifndef HAVE_DOSISH_SYSTEM
+static int uid_set = 0;
+static uid_t real_uid, file_uid;
+#endif /*!HAVE_DOSISH_SYSTEM*/
+
+/* Write DATA of size BYTES to FD, until all is written or an error
+   occurs.  */
+ssize_t
+xwrite(int fd, const void *data, size_t bytes)
+{
+  char *ptr;
+  size_t todo;
+  ssize_t written = 0;
+
+  for (ptr = (char *)data, todo = bytes; todo; ptr += written, todo -= written)
+    {
+      do
+        written = write (fd, ptr, todo);
+      while (
+#ifdef WINDOWS
+             0
+#else
+             written == -1 && errno == EINTR
+#endif
+             );
+      if (written < 0)
+        break;
+    }
+  return written;
+}
+
+#if 0
+extern int debug;
+
+int
+debugmsg(const char *fmt, ...)
+{
+  va_list va;
+  int ret;
+
+  if (debug) {
+    va_start(va, fmt);
+    fprintf(stderr, "\e[4m");
+    ret = vfprintf(stderr, fmt, va);
+    fprintf(stderr, "\e[24m");
+    va_end(va);
+    return ret;
+  } else
+    return 0;
+}
+#endif
+
+/* initialize uid variables */
+#ifndef HAVE_DOSISH_SYSTEM
+static void
+init_uids(void)
+{
+  real_uid = getuid();
+  file_uid = geteuid();
+  uid_set = 1;
+}
+#endif
+
+
+/* drop all additional privileges */
+void
+drop_privs(void)
+{
+#ifndef HAVE_DOSISH_SYSTEM
+  if (!uid_set)
+    init_uids();
+  if (real_uid != file_uid) {
+    if (setuid(real_uid) < 0) {
+      perror("dropping privileges failed");
+      exit(EXIT_FAILURE);
+    }
+    file_uid = real_uid;
+  }
+#endif
+}