1 files changed, 84 insertions, 0 deletions
diff --git a/src/apop.c b/src/apop.c
new file mode 100644
index 0000000..ce423a5
--- /dev/null
+++ b/src/apop.c
@@ -0,0 +1,84 @@
+/* This file is part of tagr.
+   Copyright (C) 2009 Sergey Poznyakoff
+
+   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 3, 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 <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <tagr.h>
+
+#include <md5.h>
+
+static char *msg_id;
+
+const char *
+tagr_auth_init ()
+{
+  asprintf (&msg_id, "<%lu.%lu@%s>",
+	    (unsigned long) getpid (),
+	    (unsigned long) time (NULL),
+	    hostname);
+  return msg_id;
+}
+
+static int
+verify_apop (const char *password, const char *user_digest)
+{
+  int i;
+  struct md5_ctx md5context;
+  unsigned char md5digest[16];
+  char buf[sizeof (md5digest) * 2 + 1];
+  char *p;
+
+  md5_init_ctx (&md5context);
+  md5_process_bytes (msg_id, strlen (msg_id), &md5context);
+  md5_process_bytes (password, strlen (password), &md5context);
+  md5_finish_ctx (&md5context, md5digest);
+
+  for (i = 0, p = buf; i < 16; i++, p += 2)
+    sprintf (p, "%02x", md5digest[i]);
+  return strcmp (user_digest, buf);
+}
+
+int
+tagr_auth (const char *username, const char *authstr)
+{
+  int rc = 1;
+  char *password;
+
+  rc = udb_get_password (username, &password);
+  if (rc == 1)
+    {
+      logmsg (L_ERR, _("no such user `%s'"), username);
+    }
+  else if (rc == 0)
+    {
+      rc = verify_apop (password, authstr);
+      if (rc) 
+	logmsg (L_ERR, _("authentication failed for `%s'"),
+		username);
+      else
+	verbose (1, _("%s authenticated"), username);
+      udb_free_password (password);
+    }
+  return rc;
+}
+