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|
# 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
UnauthorizedError = Class.new(StandardError)
NotFoundError = Class.new(StandardError)
ProjectCreationError = Class.new(StandardError)
ProjectMovedError = Class.new(NotFoundError)
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.',
account_blocked: 'Your account has been blocked.',
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."
}.freeze
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, :project, :protocol, :authentication_abilities, :namespace_path, :project_path, :redirected_path, :auth_result_type
def initialize(actor, project, protocol, authentication_abilities:, namespace_path: nil, project_path: nil, redirected_path: nil, auth_result_type: nil)
@actor = actor
@project = project
@protocol = protocol
@authentication_abilities = authentication_abilities
@namespace_path = namespace_path
@project_path = project_path
@redirected_path = redirected_path
@auth_result_type = auth_result_type
end
def check(cmd, changes)
check_protocol!
check_valid_actor!
check_active_user!
check_authentication_abilities!(cmd)
check_command_disabled!(cmd)
check_command_existence!(cmd)
check_db_accessibility!(cmd)
ensure_project_on_push!(cmd, changes)
check_project_accessibility!
add_project_moved_message!
check_repository_existence!
case cmd
when *DOWNLOAD_COMMANDS
check_download_access!
when *PUSH_COMMANDS
check_push_access!(changes)
end
true
end
def guest_can_download_code?
Guest.can?(:download_code, project)
end
def user_can_download_code?
authentication_abilities.include?(:download_code) && user_access.can_do_action?(:download_code)
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_valid_actor!
return unless actor.is_a?(Key)
unless actor.valid?
raise UnauthorizedError, "Your SSH key #{actor.errors[:key].first}."
end
end
def check_protocol!
return if request_from_ci_build?
unless protocol_allowed?
raise UnauthorizedError, "Git access over #{protocol.upcase} is not allowed"
end
end
def check_active_user!
if user && !user_access.allowed?
raise UnauthorizedError, ERROR_MESSAGES[:account_blocked]
end
end
def check_authentication_abilities!(cmd)
case cmd
when *DOWNLOAD_COMMANDS
unless authentication_abilities.include?(:download_code) || authentication_abilities.include?(:build_download_code)
raise UnauthorizedError, ERROR_MESSAGES[:auth_download]
end
when *PUSH_COMMANDS
unless authentication_abilities.include?(:push_code)
raise UnauthorizedError, ERROR_MESSAGES[:auth_upload]
end
end
end
def check_project_accessibility!
if project.blank? || !can_read_project?
raise NotFoundError, ERROR_MESSAGES[:project_not_found]
end
end
def add_project_moved_message!
return if redirected_path.nil?
project_moved = Checks::ProjectMoved.new(project, user, protocol, redirected_path)
project_moved.add_message
end
def check_command_disabled!(cmd)
if upload_pack?(cmd)
check_upload_pack_disabled!
elsif receive_pack?(cmd)
check_receive_pack_disabled!
end
end
def check_upload_pack_disabled!
if http? && upload_pack_disabled_over_http?
raise UnauthorizedError, ERROR_MESSAGES[:upload_pack_disabled_over_http]
end
end
def check_receive_pack_disabled!
if http? && receive_pack_disabled_over_http?
raise UnauthorizedError, ERROR_MESSAGES[:receive_pack_disabled_over_http]
end
end
def check_command_existence!(cmd)
unless ALL_COMMANDS.include?(cmd)
raise UnauthorizedError, ERROR_MESSAGES[:command_not_allowed]
end
end
def check_db_accessibility!(cmd)
return unless receive_pack?(cmd)
if Gitlab::Database.read_only?
raise UnauthorizedError, push_to_read_only_message
end
end
def ensure_project_on_push!(cmd, changes)
return if project || deploy_key?
return unless receive_pack?(cmd) && changes == '_any' && authentication_abilities.include?(:push_code)
namespace = Namespace.find_by_full_path(namespace_path)
return unless user&.can?(:create_projects, namespace)
project_params = {
path: project_path,
namespace_id: namespace.id,
visibility_level: Gitlab::VisibilityLevel::PRIVATE
}
project = Projects::CreateService.new(user, project_params).execute
unless project.saved?
raise ProjectCreationError, "Could not create project: #{project.errors.full_messages.join(', ')}"
end
@project = project
user_access.project = @project
Checks::ProjectCreated.new(project, user, protocol).add_message
end
def check_repository_existence!
unless repository.exists?
raise NotFoundError, ERROR_MESSAGES[:no_repo]
end
end
def check_download_access!
passed = deploy_key? ||
user_can_download_code? ||
build_can_download_code? ||
guest_can_download_code?
unless passed
raise UnauthorizedError, ERROR_MESSAGES[:download]
end
end
def check_push_access!(changes)
if project.repository_read_only?
raise UnauthorizedError, ERROR_MESSAGES[:read_only]
end
if deploy_key?
unless deploy_key.can_push_to?(project)
raise UnauthorizedError, ERROR_MESSAGES[:deploy_key_upload]
end
elsif user
# User access is verified in check_change_access!
else
raise UnauthorizedError, ERROR_MESSAGES[:upload]
end
return if changes.blank? # Allow access this is needed for EE.
check_change_access!(changes)
end
def check_change_access!(changes)
# 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
changes_list = Gitlab::ChangesList.new(changes)
# 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
def check_single_change_access(change, skip_lfs_integrity_check: false)
Checks::ChangeAccess.new(
change,
user_access: user_access,
project: project,
skip_authorization: deploy_key?,
skip_lfs_integrity_check: skip_lfs_integrity_check,
protocol: protocol
).exec
end
def deploy_key
actor if deploy_key?
end
def deploy_key?
actor.is_a?(DeployKey)
end
def ci?
actor == :ci
end
def can_read_project?
if deploy_key?
deploy_key.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 upload_pack?(command)
command == 'git-upload-pack'
end
def receive_pack?(command)
command == '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 user
return @user if defined?(@user)
@user =
case actor
when User
actor
when DeployKey
nil
when Key
actor.user
when :ci
nil
end
end
def user_access
@user_access ||= if ci?
CiAccess.new
else
UserAccess.new(user, project: project)
end
end
def push_to_read_only_message
ERROR_MESSAGES[:cannot_push_to_read_only]
end
def repository
project.repository
end
end
end
|