修正：某些主机ssh服务不支持查询所支持的认证方式，导致无法进行ssh连接。

server/tp_core/protocol/ssh/ssh_session.cpp

@@ -249,7 +249,8 @@ int SshSession::_on_auth_password_request(ssh_session session, const char *user,
 
 		// 因为是从sftp会话得来的登录数据，因此限制本会话只能用于sftp，不允许再使用shell了。
 		_this->_enter_sftp_mode();
-	} else {
+	}
+	else {
 		_this->m_server_ip = sess_info->host_ip;
 		_this->m_server_port = sess_info->host_port;
 		_this->m_auth_mode = sess_info->auth_mode;
@@ -310,31 +311,41 @@ int SshSession::_on_auth_password_request(ssh_session session, const char *user,
 
 	// 检查服务端支持的认证协议
 	ssh_userauth_none(_this->m_srv_session, NULL);
-	int auth_methods = ssh_userauth_list(_this->m_srv_session, NULL);
+	// int auth_methods = ssh_userauth_list(_this->m_srv_session, NULL);
 
 	if (_this->m_auth_mode == TS_AUTH_MODE_PASSWORD) {
-		if (auth_methods & SSH_AUTH_METHOD_PASSWORD) {
 		rc = ssh_userauth_password(_this->m_srv_session, NULL, _this->m_user_auth.c_str());
-			if (rc != SSH_AUTH_SUCCESS) {
+		if (rc == SSH_AUTH_SUCCESS) {
+			_this->m_is_logon = true;
+			return SSH_AUTH_SUCCESS;
+		}
+		else if (rc == SSH_AUTH_ERROR) {
 			EXLOGE("[ssh] invalid password for password mode to login to real SSH server %s:%d.\n", _this->m_server_ip.c_str(), _this->m_server_port);
 			_this->m_have_error = true;
 			_this->m_retcode = SESS_STAT_ERR_AUTH_DENIED;
-				return SSH_AUTH_DENIED;
+			return SSH_AUTH_ERROR;
 		}
-		}
+
-		else if (auth_methods & SSH_AUTH_METHOD_INTERACTIVE) {
+		// 可能远程主机不允许用密码登录，试试交互式登录
-			bool is_login = false;
 		for (;;) {
 			rc = ssh_userauth_kbdint(_this->m_srv_session, NULL, NULL);
-				if (rc != SSH_AUTH_INFO)
+			if (rc != SSH_AUTH_INFO) {
+				EXLOGE("[ssh] try ssh interactive login failed at init, errcode=%d.\n", rc);
 				break;
+			}
 
-				if(ssh_userauth_kbdint_getnprompts(_this->m_srv_session) != 1)
+			if (ssh_userauth_kbdint_getnprompts(_this->m_srv_session) != 1) {
+				EXLOGE("[ssh] ssh interactive login, prompt count not 1.\n");
 				break;
+			}
 
 			rc = ssh_userauth_kbdint_setanswer(_this->m_srv_session, 0, _this->m_user_auth.c_str());
-				if (rc < 0)
+			if (rc != SSH_AUTH_SUCCESS) {
-					break;
+				EXLOGE("[ssh] invalid password for interactive mode to login to real SSH server %s:%d.\n", _this->m_server_ip.c_str(), _this->m_server_port);
+				_this->m_have_error = true;
+				_this->m_retcode = SESS_STAT_ERR_AUTH_DENIED;
+				return SSH_AUTH_ERROR;
+			}
 
 			// 有时候服务端会再发一个空的提示来完成交互
 			rc = ssh_userauth_kbdint(_this->m_srv_session, NULL, NULL);
@@ -346,68 +357,50 @@ int SshSession::_on_auth_password_request(ssh_session session, const char *user,
 					break;
 			}
 
-				if(rc == SSH_AUTH_SUCCESS)
+			if (rc == SSH_AUTH_SUCCESS) {
-					is_login = true;
+				_this->m_is_logon = true;
+				return SSH_AUTH_SUCCESS;
+			}
 			break;
 		}
 
-			if (!is_login) {
+		EXLOGE("[ssh] can not use password mode or interactive mode ot login to real SSH server %s:%d.\n", _this->m_server_ip.c_str(), _this->m_server_port);
-				EXLOGE("[ssh] invalid password for keyboard-interactive mode to login to real SSH server %s:%d.\n", _this->m_server_ip.c_str(), _this->m_server_port);
 		_this->m_have_error = true;
 		_this->m_retcode = SESS_STAT_ERR_AUTH_DENIED;
-				return SSH_AUTH_DENIED;
+		return SSH_AUTH_ERROR;
-			}
-		}
-		else {
-			EXLOGE("[ssh] real SSH server [%s:%d] does not support password or keyboard-interactive login.\n", _this->m_server_ip.c_str(), _this->m_server_port);
-			_this->m_have_error = true;
-			_this->m_retcode = SESS_STAT_ERR_AUTH_DENIED;
-			return SSH_AUTH_DENIED;
-		}
 	}
 	else if (_this->m_auth_mode == TS_AUTH_MODE_PRIVATE_KEY) {
-		if (auth_methods & SSH_AUTH_METHOD_PUBLICKEY) {
 		ssh_key key = NULL;
 		if (SSH_OK != ssh_pki_import_privkey_base64(_this->m_user_auth.c_str(), NULL, NULL, NULL, &key)) {
 			EXLOGE("[ssh] can not import private-key for auth.\n");
 			_this->m_have_error = true;
 			_this->m_retcode = SESS_STAT_ERR_BAD_SSH_KEY;
-				return SSH_AUTH_DENIED;
+			return SSH_AUTH_ERROR;
 		}
 
 		rc = ssh_userauth_publickey(_this->m_srv_session, NULL, key);
-			if (rc != SSH_OK) {
 		ssh_key_free(key);
-				EXLOGE("[ssh] invalid private-key for login to real SSH server %s:%d.\n", _this->m_server_ip.c_str(), _this->m_server_port);
-				_this->m_have_error = true;
-				_this->m_retcode = SESS_STAT_ERR_AUTH_DENIED;
-				return SSH_AUTH_DENIED;
-			}
 
-			ssh_key_free(key);
+		if (rc == SSH_AUTH_SUCCESS) {
+			_this->m_is_logon = true;
+			return SSH_AUTH_SUCCESS;
 		}
 		else {
-			EXLOGE("[ssh] real SSH server [%s:%d] does not support public key login.\n", _this->m_server_ip.c_str(), _this->m_server_port);
+			EXLOGE("[ssh] failed to use private-key to login to real SSH server %s:%d.\n", _this->m_server_ip.c_str(), _this->m_server_port);
 			_this->m_have_error = true;
 			_this->m_retcode = SESS_STAT_ERR_AUTH_DENIED;
-			return SSH_AUTH_DENIED;
+			return SSH_AUTH_ERROR;
 		}
-
 	}
-	else if (_this->m_auth_mode == TS_AUTH_MODE_NONE)
+	else if (_this->m_auth_mode == TS_AUTH_MODE_NONE) {
-	{
+		return SSH_AUTH_ERROR;
-		// do nothing.
-		return SSH_AUTH_DENIED;
 	}
 	else {
 		EXLOGE("[ssh] invalid auth mode.\n");
 		_this->m_have_error = true;
 		_this->m_retcode = SESS_STAT_ERR_AUTH_DENIED;
-		return SSH_AUTH_DENIED;
+		return SSH_AUTH_ERROR;
 	}
-
-	_this->m_is_logon = true;
-	return SSH_AUTH_SUCCESS;
 }
 
 ssh_channel SshSession::_on_new_channel_request(ssh_session session, void *userdata) {