skynet-accounts

skynet-accounts is a service that stores Skynet user account data. It uses MongoDB for data storage.

Setup steps

The .env file

All local secrets are loaded from a .env file in the root directory of the project.

Those are (example values):

ACCOUNTS_EMAIL_URI="smtps://<email address>:<email password>@<smtp server for email>/?skip_ssl_verify=false"
ACCOUNTS_JWKS_FILE="/accounts/conf/jwks.json"
COOKIE_DOMAIN="siasky.net"
COOKIE_HASH_KEY="any thirty-two byte string is ok"
COOKIE_ENC_KEY="any thirty-two byte string is ok"
PORTAL_DOMAIN="https://siasky.net"
SERVER_DOMAIN="eu-ger-1.siasky.net"
SKYNET_DB_HOST="localhost"
SKYNET_DB_PORT="27017"
SKYNET_DB_USER="username"
SKYNET_DB_PASS="password"
STRIPE_API_KEY="put-your-key-here"
STRIPE_WEBHOOK_SECRET="put-your-secret-here"

There are some optional ones, as well:

ACCOUNTS_EMAIL_FROM="norepl@siasky.net"
SKYNET_ACCOUNTS_LOG_LEVEL=trace
ACCOUNTS_MAX_NUM_API_KEYS_PER_USER=1000

Meaning of environment variables:

• ACCOUNTS_EMAIL_URI is the full email URI (including credentials) for sending emails. example ACCOUNTS_EMAIL_URI=smtps://hello@gmail.com:MYSUP3R$TRONGPW@smtp.gmail.com:465/?skip_ssl_verify=false
• ACCOUNTS_EMAIL_FROM allows us to set the FROM email on our outgoing emails. If it's not set we will use the user from ACCOUNTS_EMAIL_URI.
• ACCOUNTS_JWKS_FILE is the file which contains the JWKS accounts uses to sign the JWTs it issues for its users. It defaults to /accounts/conf/jwks.json. This file is required.
• COOKIE_DOMAIN defines the domain for which we set the login cookies. It usually matches PORTAL_DOMAIN.
• COOKIE_HASH_KEY and COOKIE_ENC_KEY are used for securing the cookie which holds the user's JWT token.
• PORTAL_DOMAIN is the domain for which we issue our JWTs.
• SERVER_DOMAIN defines the domain name of the current server in a cluster setup. In a single server setup it should match PORTAL_DOMAIN.
• SKYNET_ACCOUNTS_LOG_LEVEL defines the log level used by the service. It goes from trace to panic. The recommended value is info.
• SKYNET_DB_HOST, SKYNET_DB_PORT, SKYNET_DB_USER, and SKYNET_DB_PASS tell accounts how to connect to the MongoDB instance it's supposed to use.
• STRIPE_API_KEY, STRIPE_WEBHOOK_SECRET allow us to process user payments made via Stripe.
• ACCOUNTS_MAX_NUM_API_KEYS_PER_USER defines the maximum number of API keys a user can create. If a user needs to add a new key after reaching that number, they would need to first delete another.

Generating a JWKS and Cookie Keys

The JSON Web Key Set is a set of cryptographic keys used to sign the JSON Web Tokens accounts issues for its users. These tokens are used to authorize users in front of the service and are required for its operation.

You can generate the necessary jwks.json file and proper keys for the two COOKIE variables by cloning this repo and running:

git clone https://github.com/SkynetLabs/skynet-accounts.git
cd skynet-accounts
make docker-generate

This will generate the needed information in an output/ directory. The COOKIE variables are in the output/env file and the JWKS is in the output/jwks.json file.

Solving a challenge

Accounts support challenge-response based login and registration. The way that works is by first requesting a challenge (e.g. GET /login) and then sending a solution to that challenge (e.g. POST /login).

Here is some sample code which demonstrates how to solve the challenge:

package main

import (
	"crypto/ed25519"
	"encoding/hex"
	"fmt"

	"github.com/SkynetLabs/skynet-accounts/database"
	"go.sia.tech/siad/crypto"
)

type ChallengeResponse struct {
	Response  []byte
	Signature []byte
}

func solveChallenge(sk crypto.SecretKey, challenge, challengeType, recipient string) ChallengeResponse {
	challengeBytes, _ := hex.DecodeString(challenge)
	response := append([]byte{}, challengeBytes...)
	response = append(response, []byte(challengeType)...)
	response = append(response, []byte(recipient)...)
	sig := ed25519.Sign(ed25519.PrivateKey(sk[:]), response)
	return ChallengeResponse{
		Response:  response,
		Signature: sig,
	}
}

func main() {
	seedBytes, _ := hex.DecodeString("c7665dc134829be6953e4fc126f47bfabfbef2045e3b43cef2ed00879c545b8f")
	var seed [32]byte
	copy(seed[:], seedBytes)
	sk, _ := crypto.GenerateKeyPairDeterministic(seed)

	challengeHex := "818e7c0e2a3de6fbd71bebd53117dcc3959e069ffaf573724d5b27c1bc5357b4"
	challengeType := database.ChallengeTypeLogin

	recipient := "siasky.net"
	resp := solveChallenge(sk, challengeHex, challengeType, recipient)

	fmt.Println("Response:", hex.EncodeToString(resp.Response))
	fmt.Println("Signature:", hex.EncodeToString(resp.Signature))
}

License

Skynet Accounts uses a custom License. The Skynet License is a source code license that allows you to use, modify and distribute the software, but you must preserve the payment mechanism in the software.

For the purposes of complying with our code license, you can use the following Siacoin address:

fb6c9320bc7e01fbb9cd8d8c3caaa371386928793c736837832e634aaaa484650a3177d6714a

Recommended reading

• JSON and BSON
• Using the official MongoDB Go driver