debian-mirror-gitlab/lib/gitlab/git_access.rb
2021-02-22 17:27:13 +05:30

568 lines
16 KiB
Ruby

# frozen_string_literal: true
# Check a user's access to perform a git action. All public methods in this
# class return an instance of `GitlabAccessStatus`
module Gitlab
class GitAccess
include Gitlab::Utils::StrongMemoize
ForbiddenError = Class.new(StandardError)
NotFoundError = Class.new(StandardError)
TimeoutError = Class.new(StandardError)
ProjectMovedError = Class.new(NotFoundError)
# Use the magic string '_any' to indicate we do not know what the
# changes are. This is also what gitlab-shell does.
ANY = '_any'
ERROR_MESSAGES = {
upload: 'You are not allowed to upload code for this project.',
download: 'You are not allowed to download code from this project.',
auth_upload: 'You are not allowed to upload code.',
auth_download: 'You are not allowed to download code.',
deploy_key_upload: 'This deploy key does not have write access to this project.',
no_repo: 'A repository for this project does not exist yet.',
project_not_found: 'The project you were looking for could not be found.',
command_not_allowed: "The command you're trying to execute is not allowed.",
upload_pack_disabled_over_http: 'Pulling over HTTP is not allowed.',
receive_pack_disabled_over_http: 'Pushing over HTTP is not allowed.',
read_only: 'The repository is temporarily read-only. Please try again later.',
cannot_push_to_read_only: "You can't push code to a read-only GitLab instance.",
push_code: 'You are not allowed to push code to this project.'
}.freeze
INTERNAL_TIMEOUT = 50.seconds.freeze
LOG_HEADER = <<~MESSAGE
Push operation timed out
Timing information for debugging purposes:
MESSAGE
DOWNLOAD_COMMANDS = %w{git-upload-pack git-upload-archive}.freeze
PUSH_COMMANDS = %w{git-receive-pack}.freeze
ALL_COMMANDS = DOWNLOAD_COMMANDS + PUSH_COMMANDS
attr_reader :actor, :protocol, :authentication_abilities,
:repository_path, :redirected_path, :auth_result_type,
:cmd, :changes
attr_accessor :container
def self.error_message(key)
self.ancestors.each do |cls|
return cls.const_get('ERROR_MESSAGES', false).fetch(key)
rescue NameError, KeyError
next
end
raise ArgumentError, "No error message defined for #{key}"
end
def initialize(actor, container, protocol, authentication_abilities:, repository_path: nil, redirected_path: nil, auth_result_type: nil)
@actor = actor
@container = container
@protocol = protocol
@authentication_abilities = Array(authentication_abilities)
@repository_path = repository_path
@redirected_path = redirected_path
@auth_result_type = auth_result_type
end
def check(cmd, changes)
@changes = changes
@cmd = cmd
check_protocol!
check_valid_actor!
check_active_user!
check_authentication_abilities!
check_command_disabled!
check_command_existence!
check_otp_session!
custom_action = check_custom_action
return custom_action if custom_action
check_db_accessibility!
check_container!
check_repository_existence!
case cmd
when *DOWNLOAD_COMMANDS
check_download_access!
when *PUSH_COMMANDS
check_push_access!
end
success_result
end
def logger
@logger ||= Checks::TimedLogger.new(timeout: INTERNAL_TIMEOUT, header: LOG_HEADER)
end
def guest_can_download_code?
Guest.can?(download_ability, container)
end
def deploy_key_can_download_code?
authentication_abilities.include?(:download_code) &&
deploy_key? &&
deploy_key.has_access_to?(container) &&
(project? && project&.repository_access_level != ::Featurable::DISABLED)
end
def user_can_download_code?
authentication_abilities.include?(:download_code) &&
user_access.can_do_action?(download_ability)
end
# @return [Symbol] the name of a Declarative Policy ability to check
def download_ability
raise NotImplementedError
end
# @return [Symbol] the name of a Declarative Policy ability to check
def push_ability
raise NotImplementedError
end
def build_can_download_code?
authentication_abilities.include?(:build_download_code) && user_access.can_do_action?(:build_download_code)
end
def request_from_ci_build?
return false unless protocol == 'http'
auth_result_type == :build || auth_result_type == :ci
end
def protocol_allowed?
Gitlab::ProtocolAccess.allowed?(protocol)
end
private
def check_container!
# Strict nil check, to avoid any surprises with Object#present?
# which can delegate to #empty?
raise NotFoundError, not_found_message if container.nil?
check_project! if project?
end
def check_project!
check_project_accessibility!
add_project_moved_message!
end
def check_custom_action
# no-op: Overridden in EE
end
def check_for_console_messages
return console_messages unless key?
key_status = Gitlab::Auth::KeyStatusChecker.new(actor)
if key_status.show_console_message?
console_messages.push(key_status.console_message)
else
console_messages
end
end
def console_messages
[]
end
def check_valid_actor!
return unless key?
unless actor.valid?
raise ForbiddenError, "Your SSH key #{actor.errors[:key].first}."
end
end
def check_protocol!
return if request_from_ci_build?
unless protocol_allowed?
raise ForbiddenError, "Git access over #{protocol.upcase} is not allowed"
end
end
def check_active_user!
return unless user
unless user_access.allowed?
message = Gitlab::Auth::UserAccessDeniedReason.new(user).rejection_message
raise ForbiddenError, message
end
end
def check_authentication_abilities!
case cmd
when *DOWNLOAD_COMMANDS
unless authentication_abilities.include?(:download_code) || authentication_abilities.include?(:build_download_code)
raise ForbiddenError, error_message(:auth_download)
end
when *PUSH_COMMANDS
unless authentication_abilities.include?(:push_code)
raise ForbiddenError, error_message(:auth_upload)
end
end
end
def check_project_accessibility!
raise NotFoundError, not_found_message unless can_read_project?
end
def not_found_message
error_message(:project_not_found)
end
def add_project_moved_message!
return if redirected_path.nil?
project_moved = Checks::ProjectMoved.new(repository, user, protocol, redirected_path)
project_moved.add_message
end
def check_command_disabled!
if upload_pack?
check_upload_pack_disabled!
elsif receive_pack?
check_receive_pack_disabled!
end
end
def check_upload_pack_disabled!
if http? && upload_pack_disabled_over_http?
raise ForbiddenError, error_message(:upload_pack_disabled_over_http)
end
end
def check_receive_pack_disabled!
if http? && receive_pack_disabled_over_http?
raise ForbiddenError, error_message(:receive_pack_disabled_over_http)
end
end
def check_command_existence!
unless ALL_COMMANDS.include?(cmd)
raise ForbiddenError, error_message(:command_not_allowed)
end
end
def check_otp_session!
return unless ssh?
return if !key? || deploy_key?
return unless Feature.enabled?(:two_factor_for_cli)
return unless user.two_factor_enabled?
if ::Gitlab::Auth::Otp::SessionEnforcer.new(actor).access_restricted?
message = "OTP verification is required to access the repository.\n\n"\
" Use: #{build_ssh_otp_verify_command}"
raise ForbiddenError, message
end
end
def build_ssh_otp_verify_command
user = "#{Gitlab.config.gitlab_shell.ssh_user}@" unless Gitlab.config.gitlab_shell.ssh_user.empty?
user_host = "#{user}#{Gitlab.config.gitlab_shell.ssh_host}"
if Gitlab.config.gitlab_shell.ssh_port != 22
"ssh #{user_host} -p #{Gitlab.config.gitlab_shell.ssh_port} 2fa_verify"
else
"ssh #{user_host} 2fa_verify"
end
end
def check_db_accessibility!
return unless receive_pack?
if Gitlab::Database.read_only?
raise ForbiddenError, push_to_read_only_message
end
end
def check_repository_existence!
raise NotFoundError, no_repo_message unless repository.exists?
end
def no_repo_message
error_message(:no_repo)
end
def check_download_access!
passed = deploy_key_can_download_code? ||
deploy_token? ||
user_can_download_code? ||
build_can_download_code? ||
guest_can_download_code?
unless passed
raise ForbiddenError, download_forbidden_message
end
end
def download_forbidden_message
error_message(:download)
end
def project?
# Strict nil check, to avoid any surprises with Object#present?
# which can delegate to #empty?
!project.nil?
end
def project
container if container.is_a?(::Project)
end
def check_push_access!
if project&.repository_read_only?
raise ForbiddenError, error_message(:read_only)
end
if deploy_key?
unless deploy_key.can_push_to?(project)
raise ForbiddenError, error_message(:deploy_key_upload)
end
elsif user
# User access is verified in check_change_access!
else
raise ForbiddenError, error_message(:upload)
end
check_change_access!
end
def user_can_push?
user_access.can_do_action?(push_ability)
end
def check_change_access!
return if deploy_key? && !deploy_keys_on_protected_branches_enabled?
if changes == ANY
can_push = (deploy_key? && deploy_keys_on_protected_branches_enabled?) ||
user_can_push? ||
project&.any_branch_allows_collaboration?(user_access.user)
unless can_push
raise ForbiddenError, error_message(:push_code)
end
else
# If there are worktrees with a HEAD pointing to a non-existent object,
# calls to `git rev-list --all` will fail in git 2.15+. This should also
# clear stale lock files.
project.repository.clean_stale_repository_files if project.present?
# Iterate over all changes to find if user allowed all of them to be applied
changes_list.each.with_index do |change, index|
first_change = index == 0
# If user does not have access to make at least one change, cancel all
# push by allowing the exception to bubble up
check_single_change_access(change, skip_lfs_integrity_check: !first_change)
end
end
end
def check_single_change_access(change, skip_lfs_integrity_check: false)
Checks::ChangeAccess.new(
change,
user_access: user_access,
project: project,
skip_lfs_integrity_check: skip_lfs_integrity_check,
protocol: protocol,
logger: logger
).validate!
rescue Checks::TimedLogger::TimeoutError
raise TimeoutError, logger.full_message
end
def deploy_key
actor if deploy_key?
end
def deploy_key?
actor.is_a?(DeployKey)
end
def deploy_token
actor if deploy_token?
end
def deploy_token?
actor.is_a?(DeployToken)
end
def ci?
actor == :ci
end
def key?
actor.is_a?(Key)
end
def can_read_project?
if deploy_key?
deploy_key.has_access_to?(project)
elsif deploy_token?
deploy_token.has_access_to?(project)
elsif user
user.can?(:read_project, project)
elsif ci?
true # allow CI (build without a user) for backwards compatibility
end || Guest.can?(:read_project, project)
end
def http?
protocol == 'http'
end
def ssh?
protocol == 'ssh'
end
def upload_pack?
cmd == 'git-upload-pack'
end
def receive_pack?
cmd == 'git-receive-pack'
end
def upload_pack_disabled_over_http?
!Gitlab.config.gitlab_shell.upload_pack
end
def receive_pack_disabled_over_http?
!Gitlab.config.gitlab_shell.receive_pack
end
protected
def error_message(key)
self.class.error_message(key)
end
def success_result
::Gitlab::GitAccessResult::Success.new(console_messages: check_for_console_messages)
end
def changes_list
@changes_list ||= Gitlab::ChangesList.new(changes == ANY ? [] : changes)
end
def user
strong_memoize(:user) do
case actor
when User
actor
when DeployKey
nil
when Key
actor.user
when :ci
nil
end
end
end
def user_access
@user_access ||= if ci?
CiAccess.new
elsif user && request_from_ci_build?
BuildAccess.new(user, container: container)
elsif deploy_key? && deploy_keys_on_protected_branches_enabled?
DeployKeyAccess.new(deploy_key, container: container)
else
UserAccess.new(user, container: container)
end
end
def push_to_read_only_message
error_message(:cannot_push_to_read_only)
end
def repository
container&.repository
end
def check_size_before_push!
if check_size_limit? && size_checker.above_size_limit?
raise ForbiddenError, size_checker.error_message.push_error
end
end
def check_push_size!
return unless check_size_limit?
# If there are worktrees with a HEAD pointing to a non-existent object,
# calls to `git rev-list --all` will fail in git 2.15+. This should also
# clear stale lock files.
repository.clean_stale_repository_files
# Use #check_repository_disk_size to get correct push size whenever a lot of changes
# gets pushed at the same time containing the same blobs. This is only
# doable if GIT_OBJECT_DIRECTORY_RELATIVE env var is set and happens
# when git push comes from CLI (not via UI and API).
#
# Fallback to determining push size using the changes_list so we can still
# determine the push size if env var isn't set (e.g. changes are made
# via UI and API).
if check_quarantine_size?
check_repository_disk_size
else
check_changes_size
end
end
def check_quarantine_size?
git_env = ::Gitlab::Git::HookEnv.all(repository.gl_repository)
git_env['GIT_OBJECT_DIRECTORY_RELATIVE'].present?
end
def check_repository_disk_size
check_size_against_limit(repository.object_directory_size)
end
def check_changes_size
changes_size = 0
changes_list.each do |change|
changes_size += repository.new_blobs(change[:newrev]).sum(&:size)
check_size_against_limit(changes_size)
end
end
def check_size_against_limit(size)
if size_checker.changes_will_exceed_size_limit?(size)
raise ForbiddenError, size_checker.error_message.new_changes_error
end
end
def check_size_limit?
strong_memoize(:check_size_limit) do
changes_list.any? { |change| !Gitlab::Git.blank_ref?(change[:newrev]) }
end
end
def size_checker
container.repository_size_checker
end
def deploy_keys_on_protected_branches_enabled?
Feature.enabled?(:deploy_keys_on_protected_branches, project)
end
end
end
Gitlab::GitAccess.prepend_if_ee('EE::Gitlab::GitAccess')