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|
# frozen_string_literal: true
require 'aws-sigv4'
module Aws
module Plugins
# @api private
class Sign < Seahorse::Client::Plugin
# These once had defaults. But now they are used as overrides to
# new endpoint and auth resolution.
option(:sigv4_signer)
option(:sigv4_name)
option(:sigv4_region)
option(:unsigned_operations, default: [])
supported_auth_types = %w[sigv4 bearer none]
supported_auth_types += ['sigv4a'] if Aws::Sigv4::Signer.use_crt?
SUPPORTED_AUTH_TYPES = supported_auth_types.freeze
def add_handlers(handlers, cfg)
operations = cfg.api.operation_names - cfg.unsigned_operations
handlers.add(Handler, step: :sign, operations: operations)
end
# @api private
# Return a signer with the `sign(context)` method
def self.signer_for(auth_scheme, config, region_override = nil)
case auth_scheme['name']
when 'sigv4', 'sigv4a'
SignatureV4.new(auth_scheme, config, region_override)
when 'bearer'
Bearer.new
else
NullSigner.new
end
end
class Handler < Seahorse::Client::Handler
def call(context)
signer = Sign.signer_for(
context[:auth_scheme],
context.config,
context[:sigv4_region]
)
signer.sign(context)
@handler.call(context)
end
end
# @api private
class Bearer
def initialize
end
def sign(context)
if context.http_request.endpoint.scheme != 'https'
raise ArgumentError,
'Unable to use bearer authorization on non https endpoint.'
end
token_provider = context.config.token_provider
raise Errors::MissingBearerTokenError unless token_provider&.set?
context.http_request.headers['Authorization'] =
"Bearer #{token_provider.token.token}"
end
def presign_url(*args)
raise ArgumentError, 'Bearer auth does not support presigned urls'
end
def sign_event(*args)
raise ArgumentError, 'Bearer auth does not support event signing'
end
end
# @api private
class SignatureV4
def initialize(auth_scheme, config, region_override = nil)
scheme_name = auth_scheme['name']
unless %w[sigv4 sigv4a].include?(scheme_name)
raise ArgumentError,
"Expected sigv4 or sigv4a auth scheme, got #{scheme_name}"
end
region = if scheme_name == 'sigv4a'
auth_scheme['signingRegionSet'].first
else
auth_scheme['signingRegion']
end
begin
@signer = Aws::Sigv4::Signer.new(
service: config.sigv4_name || auth_scheme['signingName'],
region: region_override || config.sigv4_region || region,
credentials_provider: config.credentials,
signing_algorithm: scheme_name.to_sym,
uri_escape_path: !!!auth_scheme['disableDoubleEncoding'],
unsigned_headers: %w[content-length user-agent x-amzn-trace-id]
)
rescue Aws::Sigv4::Errors::MissingCredentialsError
raise Aws::Errors::MissingCredentialsError
end
end
def sign(context)
req = context.http_request
apply_authtype(context, req)
reset_signature(req)
apply_clock_skew(context, req)
# compute the signature
begin
signature = @signer.sign_request(
http_method: req.http_method,
url: req.endpoint,
headers: req.headers,
body: req.body
)
rescue Aws::Sigv4::Errors::MissingCredentialsError
# Necessary for when credentials is explicitly set to nil
raise Aws::Errors::MissingCredentialsError
end
# apply signature headers
req.headers.update(signature.headers)
# add request metadata with signature components for debugging
context[:canonical_request] = signature.canonical_request
context[:string_to_sign] = signature.string_to_sign
end
def presign_url(*args)
@signer.presign_url(*args)
end
def sign_event(*args)
@signer.sign_event(*args)
end
private
def apply_authtype(context, req)
if context.operation['authtype'].eql?('v4-unsigned-body') &&
req.endpoint.scheme.eql?('https')
req.headers['X-Amz-Content-Sha256'] ||= 'UNSIGNED-PAYLOAD'
end
end
def reset_signature(req)
# in case this request is being re-signed
req.headers.delete('Authorization')
req.headers.delete('X-Amz-Security-Token')
req.headers.delete('X-Amz-Date')
req.headers.delete('x-Amz-Region-Set')
end
def apply_clock_skew(context, req)
if context.config.respond_to?(:clock_skew) &&
context.config.clock_skew &&
context.config.correct_clock_skew
endpoint = context.http_request.endpoint
skew = context.config.clock_skew.clock_correction(endpoint)
if skew.abs.positive?
req.headers['X-Amz-Date'] =
(Time.now.utc + skew).strftime('%Y%m%dT%H%M%SZ')
end
end
end
end
# @api private
class NullSigner
def sign(context)
end
def presign_url(*args)
end
def sign_event(*args)
end
end
end
end
end
|
