Fix multiple password changes in one session

src/clientiface.cpp

@@ -19,6 +19,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include <sstream>
 #include "clientiface.h"
+#include "debug.h"
 #include "network/connection.h"
 #include "network/serveropcodes.h"
 #include "remoteplayer.h"
@@ -31,6 +32,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "server/player_sao.h"
 #include "log.h"
 #include "util/srp.h"
+#include "util/string.h"
 #include "face_position_cache.h"
 
 static std::string string_sanitize_ascii(const std::string &s, u32 max_length)
@@ -649,6 +651,14 @@ void RemoteClient::resetChosenMech()
 	chosen_mech = AUTH_MECHANISM_NONE;
 }
 
+void RemoteClient::setEncryptedPassword(const std::string& pwd)
+{
+	FATAL_ERROR_IF(!str_starts_with(pwd, "#1#"), "must be srp");
+	enc_pwd = pwd;
+	// We just set SRP encrypted password, we accept only it now
+	allowed_auth_mechs = AUTH_MECHANISM_SRP;
+}
+
 void RemoteClient::setVersionInfo(u8 major, u8 minor, u8 patch, const std::string &full)
 {
 	m_version_major = major;

src/clientiface.h

@@ -243,15 +243,14 @@ public:
 	AuthMechanism chosen_mech  = AUTH_MECHANISM_NONE;
 	void *auth_data = nullptr;
 	u32 allowed_auth_mechs = 0;
-	u32 allowed_sudo_mechs = 0;
 
 	void resetChosenMech();
 
-	bool isSudoMechAllowed(AuthMechanism mech)
-	{ return allowed_sudo_mechs & mech; }
 	bool isMechAllowed(AuthMechanism mech)
 	{ return allowed_auth_mechs & mech; }
 
+	void setEncryptedPassword(const std::string& pwd);
+
 	RemoteClient();
 	~RemoteClient() = default;
 

src/network/serverpackethandler.cpp

@@ -1515,8 +1515,7 @@ void Server::handleCommand_FirstSrp(NetworkPacket* pkt)
 			return;
 		}
 
-		std::string initial_ver_key;
-		initial_ver_key = encode_srp_verifier(verification_key, salt);
+		std::string encpwd = encode_srp_verifier(verification_key, salt);
 
 		// It is possible for multiple connections to get this far with the same
 		// player name. In the end only one player with a given name will be emerged
@@ -1529,9 +1528,11 @@ void Server::handleCommand_FirstSrp(NetworkPacket* pkt)
 			DenyAccess(peer_id, SERVER_ACCESSDENIED_ALREADY_CONNECTED);
 			return;
 		}
-		m_script->createAuth(playername, initial_ver_key);
-		m_script->on_authplayer(playername, addr_s, true);
 
+		m_script->createAuth(playername, encpwd);
+		client->setEncryptedPassword(encpwd);
+
+		m_script->on_authplayer(playername, addr_s, true);
 		acceptAuth(peer_id, false);
 	} else {
 		if (cstate < CS_SudoMode) {
@@ -1550,12 +1551,13 @@ void Server::handleCommand_FirstSrp(NetworkPacket* pkt)
 			return;
 		}
 
-		std::string pw_db_field = encode_srp_verifier(verification_key, salt);
-		bool success = m_script->setPassword(playername, pw_db_field);
+		std::string encpwd = encode_srp_verifier(verification_key, salt);
+		bool success = m_script->setPassword(playername, encpwd);
 		if (success) {
 			actionstream << playername << " changes password" << std::endl;
 			SendChatMessage(peer_id, ChatMessage(CHATMESSAGE_TYPE_SYSTEM,
 				L"Password change successful."));
+			client->setEncryptedPassword(encpwd);
 		} else {
 			actionstream << playername <<
 				" tries to change password but it fails" << std::endl;
@@ -1606,7 +1608,8 @@ void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
 		AUTH_MECHANISM_LEGACY_PASSWORD : AUTH_MECHANISM_SRP;
 
 	if (wantSudo) {
-		if (!client->isSudoMechAllowed(chosen)) {
+		// Right now, the auth mechs don't change between login and sudo mode.
+		if (!client->isMechAllowed(chosen)) {
 			actionstream << "Server: Player \"" << client->getName() <<
 				"\" at " << getPeerAddress(peer_id).serializeString() <<
 				" tried to change password using unallowed mech " << chosen <<

src/server.cpp

@@ -2902,13 +2902,9 @@ void Server::acceptAuth(session_t peer_id, bool forSudoMode)
 
 		NetworkPacket resp_pkt(TOCLIENT_AUTH_ACCEPT, 1 + 6 + 8 + 4, peer_id);
 
-		// Right now, the auth mechs don't change between login and sudo mode.
-		u32 sudo_auth_mechs = client->allowed_auth_mechs;
-		client->allowed_sudo_mechs = sudo_auth_mechs;
-
 		resp_pkt << v3f(0,0,0) << (u64) m_env->getServerMap().getSeed()
 				<< g_settings->getFloat("dedicated_server_step")
-				<< sudo_auth_mechs;
+				<< client->allowed_auth_mechs;
 
 		Send(&resp_pkt);
 		m_clients.event(peer_id, CSE_AuthAccept);