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# frozen_string_literal: true
require 'rubygems'
require 'rubygems/request'
require 'rubygems/uri_formatter'
require 'rubygems/user_interaction'
require 'rubygems/request/connection_pools'
require 'resolv'
##
# RemoteFetcher handles the details of fetching gems and gem information from
# a remote source.
class Gem::RemoteFetcher
include Gem::UserInteraction
##
# A FetchError exception wraps up the various possible IO and HTTP failures
# that could happen while downloading from the internet.
class FetchError < Gem::Exception
##
# The URI which was being accessed when the exception happened.
attr_accessor :uri
def initialize(message, uri)
super message
begin
uri = URI(uri)
uri.password = 'REDACTED' if uri.password
@uri = uri.to_s
rescue URI::InvalidURIError, ArgumentError
@uri = uri
end
end
def to_s # :nodoc:
"#{super} (#{uri})"
end
end
##
# A FetchError that indicates that the reason for not being
# able to fetch data was that the host could not be contacted
class UnknownHostError < FetchError
end
@fetcher = nil
##
# Cached RemoteFetcher instance.
def self.fetcher
@fetcher ||= self.new Gem.configuration[:http_proxy]
end
attr_accessor :headers
##
# Initialize a remote fetcher using the source URI and possible proxy
# information.
#
# +proxy+
# * [String]: explicit specification of proxy; overrides any environment
# variable setting
# * nil: respect environment variables (HTTP_PROXY, HTTP_PROXY_USER,
# HTTP_PROXY_PASS)
# * <tt>:no_proxy</tt>: ignore environment variables and _don't_ use a proxy
#
# +dns+: An object to use for DNS resolution of the API endpoint.
# By default, use Resolv::DNS.
#
# +headers+: A set of additional HTTP headers to be sent to the server when
# fetching the gem.
def initialize(proxy=nil, dns=Resolv::DNS.new, headers={})
require 'net/http'
require 'stringio'
require 'time'
require 'uri'
Socket.do_not_reverse_lookup = true
@proxy = proxy
@pools = {}
@pool_lock = Mutex.new
@cert_files = Gem::Request.get_cert_files
@dns = dns
@headers = headers
end
##
# Given a source at +uri+, calculate what hostname to actually
# connect to query the data for it.
def api_endpoint(uri)
host = uri.host
begin
res = @dns.getresource "_rubygems._tcp.#{host}",
Resolv::DNS::Resource::IN::SRV
rescue Resolv::ResolvError => e
verbose "Getting SRV record failed: #{e}"
uri
else
target = res.target.to_s.strip
if /\.#{Regexp.quote(host)}\z/ =~ target
return URI.parse "#{uri.scheme}://#{target}#{uri.path}"
end
uri
end
end
##
# Given a name and requirement, downloads this gem into cache and returns the
# filename. Returns nil if the gem cannot be located.
#--
# Should probably be integrated with #download below, but that will be a
# larger, more encompassing effort. -erikh
def download_to_cache dependency
found, _ = Gem::SpecFetcher.fetcher.spec_for_dependency dependency
return if found.empty?
spec, source = found.max_by { |(s,_)| s.version }
download spec, source.uri.to_s
end
##
# Moves the gem +spec+ from +source_uri+ to the cache dir unless it is
# already there. If the source_uri is local the gem cache dir copy is
# always replaced.
def download(spec, source_uri, install_dir = Gem.dir)
cache_dir =
if Dir.pwd == install_dir then # see fetch_command
install_dir
elsif File.writable? install_dir then
File.join install_dir, "cache"
else
File.join Gem.user_dir, "cache"
end
gem_file_name = File.basename spec.cache_file
local_gem_path = File.join cache_dir, gem_file_name
FileUtils.mkdir_p cache_dir rescue nil unless File.exist? cache_dir
# Always escape URI's to deal with potential spaces and such
# It should also be considered that source_uri may already be
# a valid URI with escaped characters. e.g. "{DESede}" is encoded
# as "%7BDESede%7D". If this is escaped again the percentage
# symbols will be escaped.
unless source_uri.is_a?(URI::Generic)
begin
source_uri = URI.parse(source_uri)
rescue
source_uri = URI.parse(URI.const_defined?(:DEFAULT_PARSER) ?
URI::DEFAULT_PARSER.escape(source_uri.to_s) :
URI.escape(source_uri.to_s))
end
end
scheme = source_uri.scheme
# URI.parse gets confused by MS Windows paths with forward slashes.
scheme = nil if scheme =~ /^[a-z]$/i
# REFACTOR: split this up and dispatch on scheme (eg download_http)
# REFACTOR: be sure to clean up fake fetcher when you do this... cleaner
case scheme
when 'http', 'https', 's3' then
unless File.exist? local_gem_path then
begin
verbose "Downloading gem #{gem_file_name}"
remote_gem_path = source_uri + "gems/#{gem_file_name}"
self.cache_update_path remote_gem_path, local_gem_path
rescue Gem::RemoteFetcher::FetchError
raise if spec.original_platform == spec.platform
alternate_name = "#{spec.original_name}.gem"
verbose "Failed, downloading gem #{alternate_name}"
remote_gem_path = source_uri + "gems/#{alternate_name}"
self.cache_update_path remote_gem_path, local_gem_path
end
end
when 'file' then
begin
path = source_uri.path
path = File.dirname(path) if File.extname(path) == '.gem'
remote_gem_path = correct_for_windows_path(File.join(path, 'gems', gem_file_name))
FileUtils.cp(remote_gem_path, local_gem_path)
rescue Errno::EACCES
local_gem_path = source_uri.to_s
end
verbose "Using local gem #{local_gem_path}"
when nil then # TODO test for local overriding cache
source_path = if Gem.win_platform? && source_uri.scheme &&
!source_uri.path.include?(':') then
"#{source_uri.scheme}:#{source_uri.path}"
else
source_uri.path
end
source_path = Gem::UriFormatter.new(source_path).unescape
begin
FileUtils.cp source_path, local_gem_path unless
File.identical?(source_path, local_gem_path)
rescue Errno::EACCES
local_gem_path = source_uri.to_s
end
verbose "Using local gem #{local_gem_path}"
else
raise ArgumentError, "unsupported URI scheme #{source_uri.scheme}"
end
local_gem_path
end
##
# File Fetcher. Dispatched by +fetch_path+. Use it instead.
def fetch_file uri, *_
Gem.read_binary correct_for_windows_path uri.path
end
##
# HTTP Fetcher. Dispatched by +fetch_path+. Use it instead.
def fetch_http uri, last_modified = nil, head = false, depth = 0
fetch_type = head ? Net::HTTP::Head : Net::HTTP::Get
response = request uri, fetch_type, last_modified do |req|
headers.each { |k,v| req.add_field(k,v) }
end
case response
when Net::HTTPOK, Net::HTTPNotModified then
response.uri = uri if response.respond_to? :uri
head ? response : response.body
when Net::HTTPMovedPermanently, Net::HTTPFound, Net::HTTPSeeOther,
Net::HTTPTemporaryRedirect then
raise FetchError.new('too many redirects', uri) if depth > 10
unless location = response['Location']
raise FetchError.new("redirecting but no redirect location was given", uri)
end
location = URI.parse response['Location']
if https?(uri) && !https?(location)
raise FetchError.new("redirecting to non-https resource: #{location}", uri)
end
fetch_http(location, last_modified, head, depth + 1)
else
raise FetchError.new("bad response #{response.message} #{response.code}", uri)
end
end
alias :fetch_https :fetch_http
##
# Downloads +uri+ and returns it as a String.
def fetch_path(uri, mtime = nil, head = false)
uri = URI.parse uri unless URI::Generic === uri
raise ArgumentError, "bad uri: #{uri}" unless uri
unless uri.scheme
raise ArgumentError, "uri scheme is invalid: #{uri.scheme.inspect}"
end
data = send "fetch_#{uri.scheme}", uri, mtime, head
if data and !head and uri.to_s =~ /\.gz$/
begin
data = Gem.gunzip data
rescue Zlib::GzipFile::Error
raise FetchError.new("server did not return a valid file", uri.to_s)
end
end
data
rescue FetchError
raise
rescue Timeout::Error
raise UnknownHostError.new('timed out', uri.to_s)
rescue IOError, SocketError, SystemCallError => e
if e.message =~ /getaddrinfo/
raise UnknownHostError.new('no such name', uri.to_s)
else
raise FetchError.new("#{e.class}: #{e}", uri.to_s)
end
end
def fetch_s3(uri, mtime = nil, head = false)
public_uri = sign_s3_url(uri)
fetch_https public_uri, mtime, head
end
##
# Downloads +uri+ to +path+ if necessary. If no path is given, it just
# passes the data.
def cache_update_path uri, path = nil, update = true
mtime = path && File.stat(path).mtime rescue nil
data = fetch_path(uri, mtime)
if data == nil # indicates the server returned 304 Not Modified
return Gem.read_binary(path)
end
if update and path
Gem.write_binary(path, data)
end
data
end
##
# Returns the size of +uri+ in bytes.
def fetch_size(uri) # TODO: phase this out
response = fetch_path(uri, nil, true)
response['content-length'].to_i
end
def correct_for_windows_path(path)
if path[0].chr == '/' && path[1].chr =~ /[a-z]/i && path[2].chr == ':'
path[1..-1]
else
path
end
end
##
# Performs a Net::HTTP request of type +request_class+ on +uri+ returning
# a Net::HTTP response object. request maintains a table of persistent
# connections to reduce connect overhead.
def request(uri, request_class, last_modified = nil)
proxy = proxy_for @proxy, uri
pool = pools_for(proxy).pool_for uri
request = Gem::Request.new uri, request_class, last_modified, pool
request.fetch do |req|
yield req if block_given?
end
end
def https?(uri)
uri.scheme.downcase == 'https'
end
def close_all
@pools.each_value {|pool| pool.close_all}
end
protected
# we have our own signing code here to avoid a dependency on the aws-sdk gem
# fortunately, a simple GET request isn't too complex to sign properly
def sign_s3_url(uri, expiration = nil)
require 'base64'
require 'openssl'
unless uri.user && uri.password
raise FetchError.new("credentials needed in s3 source, like s3://key:secret@bucket-name/", uri.to_s)
end
expiration ||= s3_expiration
canonical_path = "/#{uri.host}#{uri.path}"
payload = "GET\n\n\n#{expiration}\n#{canonical_path}"
digest = OpenSSL::HMAC.digest('sha1', uri.password, payload)
# URI.escape is deprecated, and there isn't yet a replacement that does quite what we want
signature = Base64.encode64(digest).gsub("\n", '').gsub(/[\+\/=]/) { |c| BASE64_URI_TRANSLATE[c] }
URI.parse("https://#{uri.host}.s3.amazonaws.com#{uri.path}?AWSAccessKeyId=#{uri.user}&Expires=#{expiration}&Signature=#{signature}")
end
def s3_expiration
(Time.now + 3600).to_i # one hour from now
end
BASE64_URI_TRANSLATE = { '+' => '%2B', '/' => '%2F', '=' => '%3D' }.freeze
private
def proxy_for proxy, uri
Gem::Request.proxy_uri(proxy || Gem::Request.get_proxy_from_env(uri.scheme))
end
def pools_for proxy
@pool_lock.synchronize do
@pools[proxy] ||= Gem::Request::ConnectionPools.new proxy, @cert_files
end
end
end