Greenbone Vulnerability Manager
22.4.0~dev1
|
 # Greenbone Vulnerability Manager [](https://github.com/greenbone/gvmd/releases) [](https://codecov.io/gh/greenbone/gvmd) [](https://github.com/greenbone/gvmd/actions/workflows/build-and-test.yml) [](https://hub.docker.com/r/greenbone/gvmd/) [](https://hub.docker.com/r/greenbone/gvmd/) [](https://twitter.com/openvas) The Greenbone Vulnerability Manager is the central management service between security scanners and the user clients. It manages the storage of any vulnerability management configurations and of the scan results. Access to data, control commands and workflows is offered via the XML-based Greenbone Management Protocol (GMP). Controlling scanners like *[OpenVAS](https://github.com/greenbone/openvas)* is done via the Open Scanner Protocol (OSP). ## Releases All [release files](https://github.com/greenbone/gvmd/releases) are signed with the [Greenbone Community Feed integrity key](https://community.greenbone.net/t/gcf-managing-the-digital-signatures/101). This gpg key can be downloaded at https://www.greenbone.net/GBCommunitySigningKey.asc and the fingerprint is `8AE4 BE42 9B60 A59B 311C 2E73 9823 FAA6 0ED1 E580`. ## Installation and Usage This module can be configured, built and installed with following commands: ```sh cmake . make install ``` For detailed installation requirements and instructions, please see the file [INSTALL.md](INSTALL.md). The file also contains instructions for setting up `gvmd` and for connecting `gvmd` to vulnerability scanners and to the *[GSA](https://github.com/greenbone/gsa)* web interface. In case everything was installed using the defaults, then starting the manager daemon can be done with this simple command: ```sh gvmd ``` To see all available command line options of gvmd enter this command: ```sh gvmd --help ``` If you are not familiar or comfortable building from source code, we recommend that you use the Greenbone Enterprise TRIAL, a prepared virtual machine with a readily available setup. Information regarding the virtual machine is available at <https://www.greenbone.net/en/testnow>. ## Support For any question on the usage of `gvmd` please use the [Greenbone Community Portal](https://community.greenbone.net/). If you found a problem with the software, please [create an issue](https://github.com/greenbone/gvmd/issues) on GitHub. If you are a Greenbone customer you may alternatively or additionally forward your issue to the Greenbone Support Portal. ## Maintainer This project is maintained by [Greenbone Networks GmbH](https://www.greenbone.net/). ## Contributing Your contributions are highly appreciated. Please [create a pull request](https://github.com/greenbone/gvmd/pulls) on GitHub. Bigger changes need to be discussed with the development team via the [issues section at GitHub](https://github.com/greenbone/gvmd/issues) first. ## License Copyright (C) 2009-2022 [Greenbone Networks GmbH](https://www.greenbone.net/) Licensed under the [GNU Affero General Public License v3.0 or later](COPYING).
# INSTALLATION INSTRUCTIONS FOR GREENBONE VULNERABILITY MANAGER Please note: The reference system used by most of the developers is Debian GNU/Linux 'Buster' 10. The build might fail on any other system. Also, it is necessary to install dependent development packages. ## Prerequisites for Greenbone Vulnerability Manager Prerequisites: * GCC (Debian package: gcc) * cmake >= 3.0 (Debian package: cmake) * glib-2.0 >= 2.42 (Debian package: libglib2.0-dev) * gnutls >= 3.2.15 (Debian package: libgnutls28-dev) * libgvm_base, libgvm_util, libgvm_osp, libgvm_gmp >= 20.08.0 ([gvm-libs](https://github.com/greenbone/gvm-libs/tree/gvm-libs-20.08) component) * PostgreSQL database >= 9.6 (Debian packages: libpq-dev postgresql-server-dev-11) * pkg-config (Debian package: pkg-config) * libical >= 1.0.0 (Debian package: libical-dev) * xsltproc (Debian package: xsltproc) * gpgme Install these prerequisites on Debian GNU/Linux 'Buster' 10: apt-get install gcc cmake libglib2.0-dev libgnutls28-dev libpq-dev postgresql-server-dev-11 pkg-config libical-dev xsltproc libgpgme-dev Prerequisites for building documentation: * Doxygen * xsltproc (for building the GMP HTML documentation) * xmltoman (optional, for building man page) Prerequisites for building tests: * Cgreen (optional, for building tests) Please see the section "Prerequisites for Optional Features" below additional optional prerequisites. ## Compiling Greenbone Vulnerability Manager If you have installed required libraries to a non-standard location, remember to set the `PKG_CONFIG_PATH` environment variable to the location of you pkg-config files before configuring: export PKG_CONFIG_PATH=/your/location/lib/pkgconfig:$PKG_CONFIG_PATH Create a build directory and change into it with: mkdir build cd build Then configure the build with: cmake -DCMAKE_INSTALL_PREFIX=/path/to/your/installation .. Or (if you want to use the default installation path `/usr/local/`): cmake .. This only needs to be done once. Thereafter, the following commands are useful: make # build the scanner make doc # build the documentation make doc-full # build more developer-oriented documentation make tests # build tests make install # install the build make rebuild_cache # rebuild the cmake cache Please note that you may have to execute `make install` as root, especially if you have specified a prefix for which your user does not have full permissions. To clean up the build environment, simply remove the contents of the `build` directory you created above. ## Choosing the Connection Type Greenbone Vulnerability Manager can serve client connections on either a TCP socket or a UNIX domain socket. The default is a UNIX domain socket at: <install-prefix>/var/run/gvmd.sock This location can be overridden with the `--unix-socket` option, and the permissions of the socket can be specified with the `--listen-owner`, `--listen-group` and `--listen-mode` options. To use a TCP socket, call gvmd with the --listen option, for example: gvmd --listen=127.0.0.1 ## Certificate Generation All TCP-based communication with Greenbone Vulnerability Manager uses the TLS protocol to establish secure connections and for authentication and authorization. This requires the presence of a certificate infrastructure consisting of a certificate authority (CA) and a server and client certificate signed by the CA. Greenbone Vulnerability Manager uses a client certificate when connecting to a scanner via the OSP protocol. The easiest way to generate this certificate is to use the `gvm-manage-certs` script. A quick way to set up required certificates on the local system is to execute the command `gvm-manage-certs -a`. If you intend to use OSP scanners and Manager on separate systems you need to make sure that the mutual trust is properly configured via the TLS certificates. The `gvm-manage-certs` script can assist you in setting up your infrastructure. Please refer to the documentation provided with the script for usage details. If certificates have expired or in other ways there is need to update certificates for scanners, please see also section `Updating Scanner Certificates`. ## Configure PostgreSQL Database Backend ### Setting up the PostgreSQL database 1. Install Postgres. ```sh apt install postgresql postgresql-contrib postgresql-server-dev-all ``` 2. Install the pg-gvm extension. Install the pg-gvm extension library (https://github.com/greenbone/pg-gvm). For instructions on how to do this, see the README file there. 3. Run cmake and build gvmd as usual. 4. Setup Postgres User and DB (`/usr/share/doc/postgresql-common/README.Debian.gz`) ```sh sudo -u postgres bash createuser -DRS mattm # mattm is your OS login name createdb -O mattm gvmd ``` 5. Setup permissions. ```sh sudo -u postgres bash # if you logged out after step 4 psql gvmd create role dba with superuser noinherit; grant dba to mattm; # mattm is the user created in step 4 ``` 6. Make Postgres aware of the gvm libraries if not installed in a ld-aware directory. For example create file `/etc/ld.so.conf.d/gvm.conf` with appropriate path and then run `ldconfig`. 7. Run Manager as usual. 8. To run SQL on the database. ```sh psql gvmd ``` ### Switching between releases There are two factors for developers to consider when switching between releases: 1. gvmd uses C server-side extensions that link to gvm-libs, so Postgres needs to be able to find the version of gvm-libs that goes with gvmd. One way to do this is to modify `ld.so.conf` and run `ldconfig` after installing the desired gvmd version. 2. The Postgres database "gvmd" must be the version that is supported by gvmd. If it is too high, gvmd will refuse to run. If it is too low gvmd will only run if the database is migrated to the higher version. One way to handle this is to switch between different versions of the database using RENAME: ```sh sudo -u postgres psql -q --command='ALTER DATABASE gvmd RENAME TO gvmd_10;' sudo -u postgres psql -q --command='ALTER DATABASE gvmd_master RENAME TO gvmd;' ``` ### Analyzing the size of the tables In case the database grows in size and you want to understand which of the tables is responsible for it, there are two queries to check table sizes: Biggest relations: ```sql SELECT nspname || '.' || relname AS "relation", pg_size_pretty(pg_relation_size(C.oid)) AS "size" FROM pg_class C LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace) WHERE nspname NOT IN ('pg_catalog', 'information_schema') ORDER BY pg_relation_size(C.oid) DESC LIMIT 20; ``` Biggest tables: ```sql SELECT nspname || '.' || relname AS "relation", pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size" FROM pg_class C LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace) WHERE nspname NOT IN ('pg_catalog', 'information_schema') AND C.relkind <> 'i' AND nspname !~ '^pg_toast' ORDER BY pg_total_relation_size(C.oid) DESC LIMIT 20; ``` These queries were taken from https://wiki.postgresql.org/wiki/Disk_Usage ## Migrating the Database (e.g. during an upgrade of GVM) If you have used Manager before (e.g. an older version which got upgraded to a newer major release), you might get the following error in your `gvmd.log` during startup: gvmd: database is wrong version If this is happening you need to migrate the database to the current data model. Use this command to run the migration: gvmd --migrate ## Creating an administrator user for GVM You can create an administrator user with the `--create-user` option of `gvmd`: gvmd --create-user=myuser The new user's password is printed on success. An administrator user can later create further users or administrators via clients like the Greenbone Security Assistant (GSA). Also, the new user can change their password via GSA. ## Set the Feed Import Owner Certain resources that were previously part of the gvmd source code are now shipped via the feed. An example is the config "Full and Fast". gvmd will only create these resources if a "Feed Import Owner" is configured: gvmd --modify-setting 78eceaec-3385-11ea-b237-28d24461215b --value <uuid_of_user> The UUIDs of all created users can be found using gvmd --get-users --verbose ## Keeping the feeds up-to-date The `gvmd Data`, `SCAP` and `CERT` Feeds should be kept up-to-date by calling the `greenbone-feed-sync` script regularely (e.g. via a cron entry): greenbone-feed-sync --type GVMD_DATA greenbone-feed-sync --type SCAP greenbone-feed-sync --type CERT Please note: The `CERT` feed sync depends on data provided by the `SCAP` feed and should be called after syncing the latter. You will need the `rsync` tool for a successful synchronization. ## Configure the default OSPD scanner socket path By default, Manager tries to connect to the default OSPD scanner via the following path: /var/run/ospd/ospd.sock If this path doesn't match your setup you need to change the socket path accordingly. Get the UUID of the `OpenVAS Default` scanner: gvmd --get-scanners Update the path (example, path needs to be adapted accordingly): gvmd --modify-scanner=<uuid of OpenVAS Default scanner> --scanner-host=<install-prefix>/var/run/ospd/ospd-openvas.sock ## Logging Configuration By default, Manager writes logs to the file <install-prefix>/var/log/gvm/gvmd.log Logging is configured entirely by the file <install-prefix>/etc/gvm/gvmd_log.conf The configuration is divided into domains like this one [md main] prepend=%t %p prepend_time_format=%Y-%m-%d %Hh%M.%S %Z file=/var/log/gvm/gvmd.log level=128 The `level` field controls the amount of logging that is written. The value of `level` can be 4 Errors. 8 Critical situation. 16 Warnings. 32 Messages. 64 Information. 128 Debug. (Lots of output.) Enabling any level includes all the levels above it. So enabling Information will include Warnings, Critical situations and Errors. To get absolutely all logging, set the level to 128 for all domains in the configuration file. Logging to `syslog` can be enabled in each domain like: [md main] prepend=%t %p prepend_time_format=%Y-%m-%d %Hh%M.%S %Z file=syslog syslog_facility=daemon level=128 ## Optimizing the database Greenbone Vulnerability Manager offers the command line option `--optimize=<name>` to run various optimization of the database. The currently supported values for `<name>` are: - `vacuum` This option can reduce the file size by freeing some unused storage space in the database. For more information see the documentation for the `VACUUM` command of the database back-end you are using. - `analyze` This option updates various internal statistics of the database used to optimize queries. For more information see the documentation for the `ANALYZE` command of the database back-end you are using. - `add-feed-permissions` This option adds new read permissions on all feed data objects for the roles defined in the "Feed Import Roles" setting if they do not exist. The new permissions will be owned by the same user as the data objects, usually the feed import owner. This does not affect the command permissions, any permissions created for users or groups, or other types of permissions like modify or delete. - `cleanup-config-prefs` This option removes duplicate preferences from Scan Configs and corrects some broken preference values. For the latter, the NVT preferences in the database must be up to date (if Manager and Scanner are both running, then this should happen automatically). - `cleanup-feed-permissions` This option removes permissions on all feed data objects for all roles that are not defined in the "Feed Import Roles" setting. This does not affect the command permissions, any permissions created for users or groups, or other types of permissions like modify or delete. - `cleanup-port-names` This cleans up the ports of results as stored in the database by removing parts that do not conform to the format `<port>/<protocol>`. For example the application name will be removed from a port using the old format `telnet (23/tcp)`, reducing it to the new format `23/tcp`. This makes filtering results and delta reports more consistent. - `cleanup-report-formats` This cleans up references to report formats that have been removed without using the DELETE_REPORT_FORMAT GMP command, for example after a built-in report format has been removed. - `cleanup-result-nvts` This cleans up results with missing result_nvt entries which can result in filters and overrides not working properly. - `cleanup-result-severities` This cleans up results with no severity by assigning the default severity set by the user owning the result. All new results should have a severity assigned but this was not ensured in older versions, so this function can be used to correct missing severity scores in older reports. - `cleanup-sequences` This cleans up id sequences that are likely to run out due to regular feed updates like the ids for config preferences. - `migrate-relay-sensors` If relays are active, this can be used to make sure all sensor type scanners have a matching relay, i.e. OSP sensors have an OSP relay and GMP scanners have a GMP relay. GMP scanners are migrated to OSP sensors if an OSP relay is available. - `rebuild-report-cache` This clears the cache containing the unfiltered result counts of all reports and fully rebuilds it. - `update-report-cache` This creates the cache containing the unfiltered result counts of all reports that are not cached yet. ## Encrypted Credentials By default, the Manager stores private key and password parts of target credentials encrypted in the database. This avoids leaking such keys via backups. To be able to do a proper restore of the data, it is important to also backup the encryption key. The easiest way to do this is to create backup of the entire directory tree <install-prefix>/var/lib/gvm/gvmd/gnupg/ and store it at a safe place independent of the database backups. This needs to be done only once after the key has been created or changed. The Manager creates the key at startup if it does not exist. To check whether the key has been generated you may use the command: gpg --homedir <install-prefix>/var/lib/gvm/gvmd/gnupg --list-secret-keys An example output would be: sec 2048R/1B55390F 2013-01-18 uid GVM Credential Encryption Your key will have the same user ID (`GVM Credential Encryption`) but another keyid (1B55390F) and another creation date (2013-01-18). Older versions of the Manager didn't used encrypted credentials. Thus, for old installations the database may hold a mix of cleartext and encrypted credentials. Note, that after changing a cleartext credential it will be saved encrypted. To encrypt all existing credentials you may use: gvmd --encrypt-all-credentials Key change: If you disable the current key (see also the gpg manual) and create a new key, this command will decrypt using the old but disabled key and then re-encrypt using the new key. The command `--decrypt-all-credentials` may be used to revert to plaintext credentials: gpg --homedir /var/lib/gvm/gvmd/gnupg -K Look for the current key and remember its keyid. Then: gpg --homedir /var/lib/gvm/gvmd/gnupg --edit-key KEYID At the prompt enter `disable` followed by `save` and `quit`. Then create a new key and re-encrypt all passwords: gvmd --create-credentials-encryption-key gvmd --encrypt-all-credentials No encryption: If for backward compatibility reasons encrypted credentials are not desired, the manager must _always_ be started with the option `--disable-encrypted-credentials`. ## Resetting Credentials Encryption Key If you lost some part of the encryption key, neither a regular migration nor a simple creation might work. In this case you need to reset the encryption key with the following procedure. There is no way to get the encrypted credentials back. You will need to enter all of them anew afterwards. Get the key fingerprint: gpg --homedir <install-prefix>/var/lib/gvm/gvmd/gnupg --list-secret-keys Remove the secret key: gpg --homedir=<prefix>/etc/openvas/gnupg --delete-secret-keys KEYID Remove the key: gpg --homedir=<prefix>/etc/openvas/gnupg --delete-keys KEYID Create a new key: gvmd --create-credentials-encryption-key Finally, reset all credentials, by hand. ## Updating Scanner Certificates If you have changed the CA certificate used to sign the server and client certificates or the client certificate itself you will need to update the certificates in Manager database as well. The database can be updated using the following command: gvmd --modify-scanner <uuid> \ --scanner-ca-pub <cacert> \ --scanner-key-pub <clientcert> \ --scanner-key-priv <clientkey> Where: - `<uuid>` refers to the UUID used by OpenVAS Manager to identify the scanner; the UUID can be retrieved with `gvmd --get-scanners`. - `<cacert>` refers to the certificate of the CA used to sign the scanner certificate. Leaving this empty will delete the CA certificate of the scanner. This option can be dropped if the scanner uses a certificate that corresponds with the default CA certificate of Manager. - `<clientcert>` refers to the certificate Manager uses to authenticate when connecting to the scanner. For a default OSP scanner setup with self-signed certificates this would be `/var/lib/gvm/CA/clientcert.pem`. - `<clientkey>` refers to the private key Manager uses to authenticate when connecting to the scanner. For a default OSP scanner setup with self-signed certificates this would be `/var/lib/gvm/private/CA/clientkey.pem`. To set just a new default CA certificate: gvmd --modify-setting 9ac801ea-39f8-11e6-bbaa-28d24461215b \ --value "`cat /var/lib/gvm/CA/cacert.pem`" Replace the path to the pem-file with the one of your setup. The UUID is the fixed one of the immutable global setting for the default CA certificate and thus does not need to be changed. ## Changing the Maximum Number of Rows per Page The maximum number of rows returned by the GMP `GET` commands, like `GET_TARGETS`, is controlled by the GMP setting "Max Rows Per Page". This setting is an upper limit on the number of resources returned by any `GET` command, regardless of the value given for `rows` in the command's filter. The default value for "Max Rows Per Page" is 1000. 0 indicates no limit. This setting can not be changed via GMP. However, the gvmd option `--modify-setting` can be used to change it. gvmd --modify-setting 76374a7a-0569-11e6-b6da-28d24461215b \ --value 100 This changes the global value of the setting, and so applies to all users. Adding `--user` to the command will set a value for maximum rows only for that user. ## Prerequisites for Optional Features Certain features of the Manager also require some programs at run time: Prerequisites for generating PDF reports: * pdflatex On Debian GNU/Linux 'Stretch' 9 the following packages can be installed to fulfill this prerequisite: apt-get install texlive-latex-extra --no-install-recommends apt-get install texlive-fonts-recommended Prerequisites for generating HTML reports: * xsltproc Prerequisites for generating verinice reports: * xsltproc, xmlstarlet, zip Prerequisites for generating credential RPM packages: * rpm * fakeroot Prerequisites for generating credential DEB packages: * dpkg * fakeroot Prerequisites for generating credentials .exe packages: * makensis (usually distributed as part of nsis) Prerequisites for generating system reports: * A program in the `PATH`, with usage `gvmcg seconds type`, where seconds is the number of seconds before now that the report covers, and type is the type of report. When called with type `titles` the script must print a list of possible types, where the name of the type is everything up to the first space and everything else is a title for the report. When called with one of these types, `gvmcg` must print a PNG in base64 encoding. When called with the special type `blank`, gvmcg must print a PNG in base64 for the Manager to use when a request for one of the titled types fails. `gvmcg` may indicate failure by simply refraining from printing. Prerequisites for signature verification: * gnupg Prerequisites for HTTP alerts: * wget Prerequisites for Alemba vFire alert: * A program in the `PATH` called `greenbone_vfire_connector` that takes the path to an XML file as described by doc/vfire-data-xml.rnc as an argument. Prerequisites for Sourcefire Connector alert: * A program in the `PATH` called `greenbone_sourcefire_connector` that takes args IP, port, PKCS12 file and report file in Sourcefire format. Prerequisites for verinice .PRO Connector alert: * A program in the `PATH` called `greenbone_verinice_connector` that takes args IP, port, username, password and report file in verinice .PRO format. Prerequisites for SCP alert: * sshpass * scp Prerequisites for Send alert: * socat Prerequisites for SNMP alert: * snmp Prerequisites for SMB alert: * python3 * smbclient Prerequisites for Tipping Point alert: * python3 * python3-lxml Prerequisites for key generation on systems with low entropy: * haveged (or a similar tool) Prerequisites for S/MIME support (e.g. email encryption): * GNU privacy guard - S/MIME version (Debian package: gpgsm) Prerequisites for certificate generation: * GnuTLS certtool (Debian package: gnutls-bin) Prerequisites (recommended) to lower sync RAM usage * xml_split (Debian package: xml-twig-tools) ## Static code analysis with the Clang Static Analyzer If you want to use the Clang Static Analyzer (https://clang-analyzer.llvm.org/) to do a static code analysis, you can do so by prefixing the configuration and build commands with `scan-build`: scan-build cmake .. scan-build make The tool will provide a hint on how to launch a web browser with the results. It is recommended to do this analysis in a separate, empty build directory and to empty the build directory before `scan-build` call.
The command line entry to the manager is defined in src/gvmd.c. The manager is a GMP server.
The GMP server is defined in src/gmpd.c. The GMP library is defined in src/gmp.c. The GMP library use the Manage library to manage credentials and tasks. The manage library is defined in src/manage.c and src/manage_sql.c .
The main daemon manager process will fork for every incoming connection and for every scheduled task.
GNU AFFERO GENERAL PUBLIC LICENSE Version 3, 19 November 2007 Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/> Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble The GNU Affero General Public License is a free, copyleft license for software and other kinds of works, specifically designed to ensure cooperation with the community in the case of network server software. The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, our General Public Licenses are intended to guarantee your freedom to share and change all versions of a program--to make sure it remains free software for all its users. When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things. Developers that use our General Public Licenses protect your rights with two steps: (1) assert copyright on the software, and (2) offer you this License which gives you legal permission to copy, distribute and/or modify the software. A secondary benefit of defending all users' freedom is that improvements made in alternate versions of the program, if they receive widespread use, become available for other developers to incorporate. Many developers of free software are heartened and encouraged by the resulting cooperation. However, in the case of software used on network servers, this result may fail to come about. The GNU General Public License permits making a modified version and letting the public access it on a server without ever releasing its source code to the public. The GNU Affero General Public License is designed specifically to ensure that, in such cases, the modified source code becomes available to the community. It requires the operator of a network server to provide the source code of the modified version running there to the users of that server. Therefore, public use of a modified version, on a publicly accessible server, gives the public access to the source code of the modified version. An older license, called the Affero General Public License and published by Affero, was designed to accomplish similar goals. This is a different license, not a version of the Affero GPL, but Affero has released a new version of the Affero GPL which permits relicensing under this license. The precise terms and conditions for copying, distribution and modification follow. TERMS AND CONDITIONS 0. Definitions. "This License" refers to version 3 of the GNU Affero General Public License. "Copyright" also means copyright-like laws that apply to other kinds of works, such as semiconductor masks. "The Program" refers to any copyrightable work licensed under this License. Each licensee is addressed as "you". "Licensees" and "recipients" may be individuals or organizations. To "modify" a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the making of an exact copy. The resulting work is called a "modified version" of the earlier work or a work "based on" the earlier work. A "covered work" means either the unmodified Program or a work based on the Program. To "propagate" a work means to do anything with it that, without permission, would make you directly or secondarily liable for infringement under applicable copyright law, except executing it on a computer or modifying a private copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as well. To "convey" a work means any kind of propagation that enables other parties to make or receive copies. Mere interaction with a user through a computer network, with no transfer of a copy, is not conveying. An interactive user interface displays "Appropriate Legal Notices" to the extent that it includes a convenient and prominently visible feature that (1) displays an appropriate copyright notice, and (2) tells the user that there is no warranty for the work (except to the extent that warranties are provided), that licensees may convey the work under this License, and how to view a copy of this License. If the interface presents a list of user commands or options, such as a menu, a prominent item in the list meets this criterion. 1. Source Code. The "source code" for a work means the preferred form of the work for making modifications to it. "Object code" means any non-source form of a work. A "Standard Interface" means an interface that either is an official standard defined by a recognized standards body, or, in the case of interfaces specified for a particular programming language, one that is widely used among developers working in that language. The "System Libraries" of an executable work include anything, other than the work as a whole, that (a) is included in the normal form of packaging a Major Component, but which is not part of that Major Component, and (b) serves only to enable use of the work with that Major Component, or to implement a Standard Interface for which an implementation is available to the public in source code form. A "Major Component", in this context, means a major essential component (kernel, window system, and so on) of the specific operating system (if any) on which the executable work runs, or a compiler used to produce the work, or an object code interpreter used to run it. The "Corresponding Source" for a work in object code form means all the source code needed to generate, install, and (for an executable work) run the object code and to modify the work, including scripts to control those activities. However, it does not include the work's System Libraries, or general-purpose tools or generally available free programs which are used unmodified in performing those activities but which are not part of the work. For example, Corresponding Source includes interface definition files associated with source files for the work, and the source code for shared libraries and dynamically linked subprograms that the work is specifically designed to require, such as by intimate data communication or control flow between those subprograms and other parts of the work. The Corresponding Source need not include anything that users can regenerate automatically from other parts of the Corresponding Source. The Corresponding Source for a work in source code form is that same work. 2. Basic Permissions. All rights granted under this License are granted for the term of copyright on the Program, and are irrevocable provided the stated conditions are met. This License explicitly affirms your unlimited permission to run the unmodified Program. The output from running a covered work is covered by this License only if the output, given its content, constitutes a covered work. This License acknowledges your rights of fair use or other equivalent, as provided by copyright law. You may make, run and propagate covered works that you do not convey, without conditions so long as your license otherwise remains in force. You may convey covered works to others for the sole purpose of having them make modifications exclusively for you, or provide you with facilities for running those works, provided that you comply with the terms of this License in conveying all material for which you do not control copyright. Those thus making or running the covered works for you must do so exclusively on your behalf, under your direction and control, on terms that prohibit them from making any copies of your copyrighted material outside their relationship with you. Conveying under any other circumstances is permitted solely under the conditions stated below. Sublicensing is not allowed; section 10 makes it unnecessary. 3. Protecting Users' Legal Rights From Anti-Circumvention Law. No covered work shall be deemed part of an effective technological measure under any applicable law fulfilling obligations under article 11 of the WIPO copyright treaty adopted on 20 December 1996, or similar laws prohibiting or restricting circumvention of such measures. When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License with respect to the covered work, and you disclaim any intention to limit operation or modification of the work as a means of enforcing, against the work's users, your or third parties' legal rights to forbid circumvention of technological measures. 4. Conveying Verbatim Copies. You may convey verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice; keep intact all notices stating that this License and any non-permissive terms added in accord with section 7 apply to the code; keep intact all notices of the absence of any warranty; and give all recipients a copy of this License along with the Program. You may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee. 5. Conveying Modified Source Versions. You may convey a work based on the Program, or the modifications to produce it from the Program, in the form of source code under the terms of section 4, provided that you also meet all of these conditions: a) The work must carry prominent notices stating that you modified it, and giving a relevant date. b) The work must carry prominent notices stating that it is released under this License and any conditions added under section 7. This requirement modifies the requirement in section 4 to "keep intact all notices". c) You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged. This License gives no permission to license the work in any other way, but it does not invalidate such permission if you have separately received it. d) If the work has interactive user interfaces, each must display Appropriate Legal Notices; however, if the Program has interactive interfaces that do not display Appropriate Legal Notices, your work need not make them do so. A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an "aggregate" if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation's users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate. 6. Conveying Non-Source Forms. You may convey a covered work in object code form under the terms of sections 4 and 5, provided that you also convey the machine-readable Corresponding Source under the terms of this License, in one of these ways: a) Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by the Corresponding Source fixed on a durable physical medium customarily used for software interchange. b) Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by a written offer, valid for at least three years and valid for as long as you offer spare parts or customer support for that product model, to give anyone who possesses the object code either (1) a copy of the Corresponding Source for all the software in the product that is covered by this License, on a durable physical medium customarily used for software interchange, for a price no more than your reasonable cost of physically performing this conveying of source, or (2) access to copy the Corresponding Source from a network server at no charge. c) Convey individual copies of the object code with a copy of the written offer to provide the Corresponding Source. This alternative is allowed only occasionally and noncommercially, and only if you received the object code with such an offer, in accord with subsection 6b. d) Convey the object code by offering access from a designated place (gratis or for a charge), and offer equivalent access to the Corresponding Source in the same way through the same place at no further charge. You need not require recipients to copy the Corresponding Source along with the object code. If the place to copy the object code is a network server, the Corresponding Source may be on a different server (operated by you or a third party) that supports equivalent copying facilities, provided you maintain clear directions next to the object code saying where to find the Corresponding Source. Regardless of what server hosts the Corresponding Source, you remain obligated to ensure that it is available for as long as needed to satisfy these requirements. e) Convey the object code using peer-to-peer transmission, provided you inform other peers where the object code and Corresponding Source of the work are being offered to the general public at no charge under subsection 6d. A separable portion of the object code, whose source code is excluded from the Corresponding Source as a System Library, need not be included in conveying the object code work. A "User Product" is either (1) a "consumer product", which means any tangible personal property which is normally used for personal, family, or household purposes, or (2) anything designed or sold for incorporation into a dwelling. In determining whether a product is a consumer product, doubtful cases shall be resolved in favor of coverage. For a particular product received by a particular user, "normally used" refers to a typical or common use of that class of product, regardless of the status of the particular user or of the way in which the particular user actually uses, or expects or is expected to use, the product. A product is a consumer product regardless of whether the product has substantial commercial, industrial or non-consumer uses, unless such uses represent the only significant mode of use of the product. "Installation Information" for a User Product means any methods, procedures, authorization keys, or other information required to install and execute modified versions of a covered work in that User Product from a modified version of its Corresponding Source. The information must suffice to ensure that the continued functioning of the modified object code is in no case prevented or interfered with solely because modification has been made. If you convey an object code work under this section in, or with, or specifically for use in, a User Product, and the conveying occurs as part of a transaction in which the right of possession and use of the User Product is transferred to the recipient in perpetuity or for a fixed term (regardless of how the transaction is characterized), the Corresponding Source conveyed under this section must be accompanied by the Installation Information. But this requirement does not apply if neither you nor any third party retains the ability to install modified object code on the User Product (for example, the work has been installed in ROM). The requirement to provide Installation Information does not include a requirement to continue to provide support service, warranty, or updates for a work that has been modified or installed by the recipient, or for the User Product in which it has been modified or installed. Access to a network may be denied when the modification itself materially and adversely affects the operation of the network or violates the rules and protocols for communication across the network. Corresponding Source conveyed, and Installation Information provided, in accord with this section must be in a format that is publicly documented (and with an implementation available to the public in source code form), and must require no special password or key for unpacking, reading or copying. 7. Additional Terms. "Additional permissions" are terms that supplement the terms of this License by making exceptions from one or more of its conditions. Additional permissions that are applicable to the entire Program shall be treated as though they were included in this License, to the extent that they are valid under applicable law. If additional permissions apply only to part of the Program, that part may be used separately under those permissions, but the entire Program remains governed by this License without regard to the additional permissions. When you convey a copy of a covered work, you may at your option remove any additional permissions from that copy, or from any part of it. (Additional permissions may be written to require their own removal in certain cases when you modify the work.) You may place additional permissions on material, added by you to a covered work, for which you have or can give appropriate copyright permission. Notwithstanding any other provision of this License, for material you add to a covered work, you may (if authorized by the copyright holders of that material) supplement the terms of this License with terms: a) Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License; or b) Requiring preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed by works containing it; or c) Prohibiting misrepresentation of the origin of that material, or requiring that modified versions of such material be marked in reasonable ways as different from the original version; or d) Limiting the use for publicity purposes of names of licensors or authors of the material; or e) Declining to grant rights under trademark law for use of some trade names, trademarks, or service marks; or f) Requiring indemnification of licensors and authors of that material by anyone who conveys the material (or modified versions of it) with contractual assumptions of liability to the recipient, for any liability that these contractual assumptions directly impose on those licensors and authors. All other non-permissive additional terms are considered "further restrictions" within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document contains a further restriction but permits relicensing or conveying under this License, you may add to a covered work material governed by the terms of that license document, provided that the further restriction does not survive such relicensing or conveying. If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the additional terms that apply to those files, or a notice indicating where to find the applicable terms. Additional terms, permissive or non-permissive, may be stated in the form of a separately written license, or stated as exceptions; the above requirements apply either way. 8. Termination. You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License (including any patent licenses granted under the third paragraph of section 11). However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice. Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, you do not qualify to receive new licenses for the same material under section 10. 9. Acceptance Not Required for Having Copies. You are not required to accept this License in order to receive or run a copy of the Program. Ancillary propagation of a covered work occurring solely as a consequence of using peer-to-peer transmission to receive a copy likewise does not require acceptance. However, nothing other than this License grants you permission to propagate or modify any covered work. These actions infringe copyright if you do not accept this License. Therefore, by modifying or propagating a covered work, you indicate your acceptance of this License to do so. 10. Automatic Licensing of Downstream Recipients. Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and propagate that work, subject to this License. You are not responsible for enforcing compliance by third parties with this License. An "entity transaction" is a transaction transferring control of an organization, or substantially all assets of one, or subdividing an organization, or merging organizations. If propagation of a covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party's predecessor in interest had or could give under the previous paragraph, plus a right to possession of the Corresponding Source of the work from the predecessor in interest, if the predecessor has it or can get it with reasonable efforts. You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you may not impose a license fee, royalty, or other charge for exercise of rights granted under this License, and you may not initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed by making, using, selling, offering for sale, or importing the Program or any portion of it. 11. Patents. A "contributor" is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. The work thus licensed is called the contributor's "contributor version". A contributor's "essential patent claims" are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version, but do not include claims that would be infringed only as a consequence of further modification of the contributor version. For purposes of this definition, "control" includes the right to grant patent sublicenses in a manner consistent with the requirements of this License. Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version. In the following three paragraphs, a "patent license" is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a patent or covenant not to sue for patent infringement). To "grant" such a patent license to a party means to make such an agreement or commitment not to enforce a patent against the party. If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available for anyone to copy, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means, then you must either (1) cause the Corresponding Source to be so available, or (2) arrange to deprive yourself of the benefit of the patent license for this particular work, or (3) arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients. "Knowingly relying" means you have actual knowledge that, but for the patent license, your conveying the covered work in a country, or your recipient's use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid. If, pursuant to or in connection with a single transaction or arrangement, you convey, or propagate by procuring conveyance of, a covered work, and grant a patent license to some of the parties receiving the covered work authorizing them to use, propagate, modify or convey a specific copy of the covered work, then the patent license you grant is automatically extended to all recipients of the covered work and works based on it. A patent license is "discriminatory" if it does not include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or (b) primarily for and in connection with specific products or compilations that contain the covered work, unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007. Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law. 12. No Surrender of Others' Freedom. If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program. 13. Remote Network Interaction; Use with the GNU General Public License. Notwithstanding any other provision of this License, if you modify the Program, your modified version must prominently offer all users interacting with it remotely through a computer network (if your version supports such interaction) an opportunity to receive the Corresponding Source of your version by providing access to the Corresponding Source from a network server at no charge, through some standard or customary means of facilitating copying of software. This Corresponding Source shall include the Corresponding Source for any work covered by version 3 of the GNU General Public License that is incorporated pursuant to the following paragraph. Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the work with which it is combined will remain governed by version 3 of the GNU General Public License. 14. Revised Versions of this License. The Free Software Foundation may publish revised and/or new versions of the GNU Affero General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU Affero General Public License "or any later version" applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU Affero General Public License, you may choose any version ever published by the Free Software Foundation. If the Program specifies that a proxy can decide which future versions of the GNU Affero General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program. Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version. 15. Disclaimer of Warranty. THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 16. Limitation of Liability. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 17. Interpretation of Sections 15 and 16. If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee. END OF TERMS AND CONDITIONS How to Apply These Terms to Your New Programs If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found. <one line to give the program's name and a brief idea of what it does.> Copyright (C) <year> <name of author> This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 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 Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see <https://www.gnu.org/licenses/>. Also add information on how to contact you by electronic and paper mail. If your software can interact with users remotely through a computer network, you should also make sure that it provides a way for users to get its source. For example, if your program is a web application, its interface could display a "Source" link that leads users to an archive of the code. There are many ways you could offer source, and different solutions will be better for different programs; see section 13 for the specific requirements. You should also get your employer (if you work as a programmer) or school, if any, to sign a "copyright disclaimer" for the program, if necessary. For more information on this, and how to apply and follow the GNU AGPL, see <https://www.gnu.org/licenses/>.