relay: add command "handshake" in weechat relay protocol and nonce to prevent replay attacks (closes #1474)

This introduces a new command called "handshake" in the weechat relay protocol.
It should be sent by the client before the "init" command, to negotiate the way
to authenticate with a password.

3 new options are added:

* relay.network.auth_password
* relay.network.hash_iterations
* relay.network.nonce_size

1 files changed, 73 insertions, 0 deletions

diff --git a/src/plugins/relay/relay-auth.h b/src/plugins/relay/relay-auth.h
new file mode 100644
index 000000000..1b5cc597e
--- /dev/null
+++ b/src/plugins/relay/relay-auth.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2003-2020 Sébastien Helleu <flashcode@flashtux.org>
+ *
+ * This file is part of WeeChat, the extensible chat client.
+ *
+ * WeeChat 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 of the License, or
+ * (at your option) any later version.
+ *
+ * WeeChat 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 WeeChat.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef WEECHAT_PLUGIN_RELAY_AUTH_H
+#define WEECHAT_PLUGIN_RELAY_AUTH_H
+
+struct t_relay_client;
+
+enum t_relay_auth_password
+{
+    RELAY_AUTH_PASSWORD_PLAIN = 0,
+    RELAY_AUTH_PASSWORD_SHA256,
+    RELAY_AUTH_PASSWORD_SHA512,
+    RELAY_AUTH_PASSWORD_PBKDF2_SHA256,
+    RELAY_AUTH_PASSWORD_PBKDF2_SHA512,
+    /* number of password auths */
+    RELAY_NUM_PASSWORD_AUTHS,
+};
+
+extern char *relay_auth_password_name[];
+
+extern int relay_auth_password_search (const char *name);
+extern char *relay_auth_generate_nonce ();
+extern int relay_auth_check_password_plain (const char *password,
+                                            const char *relay_password);
+extern int relay_auth_password (struct t_relay_client *client,
+                                const char *password,
+                                const char *relay_password);
+extern void relay_auth_parse_sha (const char *parameters,
+                                  char **salt_hexa,
+                                  char **salt,
+                                  int *salt_size,
+                                  char **hash);
+extern void relay_auth_parse_pbkdf2 (const char *parameters,
+                                     char **salt_hexa,
+                                     char **salt,
+                                     int *salt_size,
+                                     int *iterations,
+                                     char **hash);
+extern int relay_auth_check_salt (struct t_relay_client *client,
+                                  const char *salt_hexa);
+extern int relay_auth_check_hash_sha (const char *hash_algo,
+                                      const char *salt,
+                                      int salt_size,
+                                      const char *hash_sha,
+                                      const char *relay_password);
+extern int relay_auth_check_hash_pbkdf2 (const char *hash_pbkdf2_algo,
+                                         const char *salt,
+                                         int salt_size,
+                                         int iterations,
+                                         const char *hash_pbkdf2,
+                                         const char *relay_password);
+extern int relay_auth_password_hash (struct t_relay_client *client,
+                                     const char *hashed_password,
+                                     const char *relay_password);
+
+#endif /* WEECHAT_PLUGIN_RELAY_AUTH_H */