Module: Blockstack

Defined in:
lib/blockstack.rb,
lib/blockstack/version.rb

Defined Under Namespace

Classes: InvalidAuthResponse

Constant Summary collapse

USER_AGENT =
"blockstack-ruby #{VERSION}"
ALGORITHM =
"ES256K"
REQUIRED_CLAIMS =
%w(iss iat jti exp username profile public_keys)
DEFAULT_LEEWAY =

seconds

30
DEFAULT_VALID_WITHIN =

seconds

30
DEFAULT_API =
"http://localhost:6270"
VERSION =
"0.5.9"

Class Method Summary collapse

Class Method Details

.apiObject



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# File 'lib/blockstack.rb', line 21

def self.api
  @@api
end

.api=(api) ⇒ Object



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# File 'lib/blockstack.rb', line 17

def self.api=(api)
  @@api = api.nil? ? DEFAULT_API : api
end

.get_address_from_did(decentralized_id) ⇒ Object



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# File 'lib/blockstack.rb', line 91

def self.get_address_from_did(decentralized_id)
  did_type = get_did_type(decentralized_id)
  return nil if did_type != 'btc-addr'
  decentralized_id.split(':')[2]
end

.get_did_type(decentralized_id) ⇒ Object



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# File 'lib/blockstack.rb', line 84

def self.get_did_type(decentralized_id)
  did_parts = decentralized_id.split(':')
  raise 'Decentralized IDs must have 3 parts' if did_parts.length != 3
  raise 'Decentralized IDs must start with "did"' if did_parts[0].downcase != 'did'
  did_parts[1].downcase
end

.leewayObject



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# File 'lib/blockstack.rb', line 29

def self.leeway
  @@leeway
end

.leeway=(leeway) ⇒ Object



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# File 'lib/blockstack.rb', line 25

def self.leeway=(leeway)
  @@leeway = leeway.nil? ? DEFAULT_LEEWAY : leeway
end

.valid_withinObject



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# File 'lib/blockstack.rb', line 37

def self.valid_within
  @@valid_within
end

.valid_within=(valid_within) ⇒ Object



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# File 'lib/blockstack.rb', line 33

def self.valid_within=(valid_within)
  @@valid_within = valid_within.nil? ? DEFAULT_VALID_WITHIN : valid_within
end

.verify_auth_response(auth_token) ⇒ Object



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# File 'lib/blockstack.rb', line 41

def self.verify_auth_response(auth_token)
  # decode & verify token without checking signature so we can extract
  # public keys
  public_key = nil
  verify = false
  decoded_tokens = JWTB.decode auth_token, public_key, verify, algorithm: ALGORITHM
  decoded_token = decoded_tokens[0]

  REQUIRED_CLAIMS.each do |field|
    raise InvalidAuthResponse.new("Missing required '#{field}' claim.") if !decoded_token.key?(field.to_s)
  end
  raise InvalidAuthResponse.new("Missing required 'iat' claim.") if !decoded_token["iat"]
  raise InvalidAuthResponse.new("'iat' timestamp claim is skewed too far from present.") if (Time.now.to_i - decoded_token["iat"]).abs > self.valid_within

  public_keys = decoded_token['public_keys']

  raise InvalidAuthResponse.new("Invalid public_keys array: only 1 key is supported") unless public_keys.length == 1

  compressed_hex_public_key = public_keys[0]
  bignum = OpenSSL::BN.new(compressed_hex_public_key, 16)
  group = OpenSSL::PKey::EC::Group.new 'secp256k1'
  public_key = OpenSSL::PKey::EC::Point.new(group, bignum)
  ecdsa_key = OpenSSL::PKey::EC.new 'secp256k1'
  ecdsa_key.public_key = public_key
  verify = true

  # decode & verify signature
  decoded_tokens = JWTB.decode auth_token, ecdsa_key, verify, algorithm: ALGORITHM, exp_leeway: self.leeway
  decoded_token = decoded_tokens[0]

  raise InvalidAuthResponse.new("Public keys don't match issuer address") unless self.public_keys_match_issuer?(decoded_token)

  raise InvalidAuthResponse.new("Public keys don't match owner of claimed username") unless self.public_keys_match_username?(decoded_token)

  return decoded_token
rescue JWTB::VerificationError => error
  raise InvalidAuthResponse.new("Signature on JWT is invalid")
rescue JWTB::DecodeError => error
  raise InvalidAuthResponse.new("Unable to decode JWT")
rescue RuntimeError => error
  raise InvalidAuthResponse.new(error.message)
end