Crypto Sanctions Server

An http server written in Rust that allows you to check whether a crypto wallet address is on the sanctions list via json api.

The server is designed to be simple, fast and used behind a reverse proxy or load balancer. However, some of this may change over time.

At the moment, the server does not support operation over the TLS protocol, and therefore should not be used for requests over the Internet without a part capable for terminating TLS traffic (for example, nginx).

Design Principles

Server must...

• Be as fast as possible without turning source into a mess of optimized write-only code
• Be secure and follow best security practices, but no more than is required for safe use
• Follow the HTTP protocol as much as possible because of the need to be able to work with any compatible client

Things to think about before releasing 1.0:

• Boot cache for quick server startup
• Socks proxy (tor?) for outgoing requests
• Health status support for load balancing
• Command line interface options
• JSON response format
• Requesting all database records
• Batch address check
• TLS support
• Code coverage and package release

Installation

Using Cargo

You can install the server locally using the cargo package manager command:

cargo install crypto-sanctions-server

Docker

The server can run inside a docker container. Several steps required:

Clone repository

git clone git@github.com:stdfox/crypto-sanctions-server.git

Build docker image

docker build -t crypto-sanctions-server .

Run container

docker run --detach --rm --name=crypto-sanctions-server -p 8000:8000 -t crypto-sanctions-server

Manual

Clone repository

git clone git@github.com:stdfox/crypto-sanctions-server.git

Build and run

cargo run

Or build and run in release mode, with optimizations:

cargo run --release

Run on custom port

You can start the http server on a custom host and port using the following command options:

cargo run -- --host 0.0.0.0 --port 3000

Usage

Check Address

You can check the crypto address using any available http1 client, curl for example:

curl http://127.0.0.1:8000/api/crypto-sanctions/1EpMiZkQVekM5ij12nMiEwttFPcDK9XhX6

This will print the response in JSON format like this:

{"address": "1EpMiZkQVekM5ij12nMiEwttFPcDK9XhX6", "sanctioned": true}

It works the same for all blockchains, for example for an Ethereum address:

curl http://127.0.0.1:8000/api/crypto-sanctions/0xf3701f445b6bdafedbca97d1e477357839e4120d

It will print:

{"address": "0xf3701f445b6bdafedbca97d1e477357839e4120d", "sanctioned": true}

Short Alias

If you prefer short console commands to use on desktop, you can add something like this to your shell configuration file (.bashrc, .zshrc, etc):

crypto-sanctions () {
    command curl http://127.0.0.1:8000/api/crypto-sanctions/$@
}

After that you can use the command as follows:

crypto-sanctions 0xf3701f445b6bdafedbca97d1e477357839e4120d

Performance

Since this server works with an in-memory database and does not use a serializer, it is quite performant. See the benchmark result on my good old 2017 MacBook Pro (3,1 GHz Dual-Core Intel Core i5) for release build:

% ab -k -c 100 -n 1000000 -q http://127.0.0.1:8000/api/crypto-sanctions/0xf3701f445b6bdafedbca97d1e477357839e4120d
This is ApacheBench, Version 2.3 <$Revision: 1903618 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient).....done


Server Software:
Server Hostname:        127.0.0.1
Server Port:            8000

Document Path:          /api/crypto-sanctions/0xf3701f445b6bdafedbca97d1e477357839e4120d
Document Length:        77 bytes

Concurrency Level:      100
Time taken for tests:   14.328 seconds
Complete requests:      1000000
Failed requests:        0
Keep-Alive requests:    1000000
Total transferred:      209000000 bytes
HTML transferred:       77000000 bytes
Requests per second:    69793.78 [#/sec] (mean)
Time per request:       1.433 [ms] (mean)
Time per request:       0.014 [ms] (mean, across all concurrent requests)
Transfer rate:          14245.02 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       5
Processing:     0    1   0.4      1      16
Waiting:        0    1   0.4      1      16
Total:          0    1   0.4      1      16

Percentage of the requests served within a certain time (ms)
  50%      1
  66%      1
  75%      1
  80%      2
  90%      2
  95%      2
  98%      3
  99%      3
 100%     16 (longest request)

Contributing

Contributor License Agreement

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in a work by you, shall be licensed as MIT, without any additional terms or conditions.

Commit Message Guidelines

This project has a rule on how git commit messages can be formatted. This leads to messages that are more readable and easy to follow when looking through the project history.

Commit Message Format

Each commit message consists of mandatory type and a subject:

<type>: <subject>

Any line of the commit message cannot be longer 100 characters.

Examples:

docs: add contributing guidelines to readme file

build: remove unused dependencies

Revert

If the commit reverts a previous commit, it should begin with revert:, followed by the header of the reverted commit.

Type

Must be one of the following:

• build: Changes that affect the build system or external dependencies
• docs: Documentation only changes
• feat: A new feature
• fix: A bug fix
• perf: A code change that improves performance
• refactor: A code change that neither fixes a bug nor adds a feature
• style: Changes that do not affect the meaning of the code
• test: Adding missing tests or correcting existing tests

Subject

The subject contains a brief description of the change:

• use the imperative, present tense: "change" not "changed" nor "changes"
• don't capitalize the first letter
• no dot (.) at the end

License

This project is licensed under the MIT License.