Class: Coinbase::Authenticator

Inherits:
Faraday::Middleware
  • Object
show all
Defined in:
lib/coinbase/authenticator.rb

Overview

A class that builds JWTs for authenticating with the Coinbase Platform APIs.

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ Authenticator

Initializes the Authenticator.

Parameters:

  • app (Faraday::Connection) —

    The Faraday connection



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# File 'lib/coinbase/authenticator.rb', line 13

def initialize(app)
  super(app)
  @app = app
end

Instance Method Details

#build_jwt(uri) ⇒ String

Builds the JWT for the given API endpoint URI. The JWT is signed with the API key’s private key.

Parameters:

  • uri (String) —

    The API endpoint URI

Returns:

  • (String) —

    The JWT



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# File 'lib/coinbase/authenticator.rb', line 32

def build_jwt(uri)
  header = {
    typ: 'JWT',
    kid: Coinbase.configuration.api_key_name,
    nonce: SecureRandom.hex(16)
  }

  claims = {
    sub: Coinbase.configuration.api_key_name,
    iss: 'coinbase-cloud',
    aud: ['cdp_service'],
    nbf: Time.now.to_i,
    exp: Time.now.to_i + 60, # Expiration time: 1 minute from now.
    uris: [uri]
  }

  private_key = OpenSSL::PKey.read(Coinbase.configuration.api_key_private_key)
  JWT.encode(claims, private_key, 'ES256', header)
end

#call(env) ⇒ Object

Processes the request by adding the JWT to the Authorization header.

Parameters:

  • env (Faraday::Env) —

    The Faraday request environment



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# File 'lib/coinbase/authenticator.rb', line 20

def call(env)
  method = env.method.downcase.to_sym
  uri = env.url.to_s
  uri_without_protocol = URI(uri).host
  token = build_jwt("#{method.upcase} #{uri_without_protocol}#{env.url.path}")
  env.request_headers['Authorization'] = "Bearer #{token}"
  @app.call(env)
end