Metadata-Version: 2.1
Name: drb-client
Version: 0.3.0
Summary: Distributed Randomness Beacon client
Home-page: https://github.com/Snawoot/drb-client
Author: Vladislav Yarmak
Author-email: vladislav-ex-src@vm-0.com
License: MIT
Description: # drb-client
        
        Distributed Randomness Beacon client
        
        Gathers entropy from multiple [drand](https://github.com/dedis/drand) instances, securely mixes responses and outputs to kernel entropy pool or stdout. Suitable for use with [League of Entropy](https://www.cloudflare.com/leagueofentropy/) servers (see "Running" section).
        
        `drb-client` can be used as a standalone source of high-quality random number, or as additional source for entropy pool in Linux kernel. Produced amount of entropy should be sufficient to derail attacks based on RNG predictability.
        
        ## Cryptography background
        
        `drb-client` polls list of `drand` servers with given interval and requests private entropy data portion from each one. Communication between `drb-client` and `drand` is protected with AES256-GCM encryption derived on BN-256 curve on top of TLS (this is imposed by `drand` API format).
        
        `drb-client` constructs each output of entropy from at least `quorum` (`-Q` option) distinct inputs. It is assumed at least `node_count - quorum + 1` nodes produce truly unpredictable secure random numbers, so any `quorum` of distinct responses definitely contain at least one truly random input (due to [pigeonhole principle](https://en.wikipedia.org/wiki/Pigeonhole_principle)).
        
        Entropy portions from beacon servers are mixed using stateful HKDF-based mixer. Each sufficient set of random responses is used to produce random output and new salt value for HKDF mixer. Therefore, mixer output becomes unpredictable after successful generation of first output, even if all beacon servers get compromised and start feeding client with biased data.
        
        Default poll interval is 60 seconds and such interval is chosen for a reason. `drand` generates entropy for each response using its `/dev/urandom`. On Linux `urandom` gets reinitialized from `/dev/random` each 1 minute. So there is no reason to fetch random data more often: responses between reinitializations are in functional dependence.
        
        ## Installation
        
        Requires Python 3.5.3+
        
        ### From PyPI
        
        ```
        pip3 install drb-client
        ```
        
        ### From source
        
        Download or clone repository and run following command in source code directory:
        
        ```
        pip3 install .
        ```
        
        ## Running
        
        There are few available entropy sinks (option `-O`):
        
        * `devrandom` - (default) writes collected entropy into `/dev/random` device, without increment of kernel counter of available entropy in pool.
        * `stdout` - writes collected entropy into standard output.
        * `rndaddentropy` - writes collected entropy into `/dev/random` device with increment of kernel counter of available entropy in pool. Requires superuser privileges to operate.
        
        You may obtain latest `group.toml` config with list of League of Entropy servers [here](https://github.com/dedis/drand/tree/master/deploy).
        
        Run with default sink:
        
        ```
        drb-client group.toml
        ```
        
        Contribute into `/dev/random` and increment entropy counter:
        
        ```
        sudo drb-client -O rndaddentropy group.toml
        ```
        
        For logging into file see "Synopsis" section.
        
        ## Synopsis
        
        ```
        $ drb-client --help
        usage: drb-client [-h] [-v {debug,info,warn,error,fatal}] [-l FILE]
                          [-Q QUORUM] [-T PERIOD] [-w TIMEOUT]
                          [-O {stdout,rndaddentropy,devrandom}]
                          group_config
        
        Distributed Randomness Beacon client
        
        positional arguments:
          group_config          group config
        
        optional arguments:
          -h, --help            show this help message and exit
          -v {debug,info,warn,error,fatal}, --verbosity {debug,info,warn,error,fatal}
                                logging verbosity (default: info)
          -l FILE, --logfile FILE
                                log file location (default: None)
        
        poll options:
          -Q QUORUM, --quorum QUORUM
                                minimal answers required on each poll. Default value
                                is (node_count // 2 + 1). (default: None)
          -T PERIOD, --period PERIOD
                                poll interval for each source (default: 60)
          -w TIMEOUT, --timeout TIMEOUT
                                timeout for each request (default: 4)
        
        output options:
          -O {stdout,rndaddentropy,devrandom}, --output {stdout,rndaddentropy,devrandom}
                                entropy output (default: devrandom)
        ```
        
        ## Deployment
        
        You may obtain latest `group.toml` config with list of League of Entropy servers [here](https://github.com/dedis/drand/tree/master/deploy).
        
        See [deploy/drb-client.service](https://github.com/Snawoot/drb-client/blob/master/deploy/drb-client.service) for example of systemd unit file.
        
        
        ## Credits
        
        * [League of Entropy](https://www.cloudflare.com/leagueofentropy/) project
        * [drand](https://github.com/dedis/drand) project
        * Jack Lloyd for [BN256 implementation for Python](https://github.com/randombit/pairings.py)
        
Platform: UNKNOWN
Classifier: Programming Language :: Python :: 3.5
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: POSIX :: Linux
Classifier: Development Status :: 4 - Beta
Classifier: Environment :: No Input/Output (Daemon)
Classifier: Intended Audience :: System Administrators
Classifier: Natural Language :: English
Classifier: Topic :: Internet
Classifier: Topic :: Security
Classifier: Topic :: System :: Operating System Kernels :: Linux
Classifier: Topic :: Security :: Cryptography
Classifier: Topic :: Utilities
Requires-Python: >=3.5.3
Description-Content-Type: text/markdown
