iolimits

Documentation

Index

• Constants
• func ReadAtMost(reader io.Reader, limit int) ([]byte, error)

Constants

const (

	// MaxManifestBodySize is the maximum allowed size of a manifest. The limit
	// of 4 MB aligns with the one of a Docker registry:
	// https://github.com/docker/distribution/blob/a8371794149d1d95f1e846744b05c87f2f825e5a/registry/handlers/manifests.go#L30
	MaxManifestBodySize = 4 * megaByte
	// MaxAuthTokenBodySize is the maximum allowed size of an auth token.
	// The limit of 1 MB is considered to be greatly sufficient.
	MaxAuthTokenBodySize = megaByte
	// MaxSignatureListBodySize is the maximum allowed size of a signature list.
	// The limit of 4 MB is considered to be greatly sufficient.
	MaxSignatureListBodySize = 4 * megaByte
	// MaxSignatureBodySize is the maximum allowed size of a signature.
	// The limit of 4 MB is considered to be greatly sufficient.
	MaxSignatureBodySize = 4 * megaByte
	// MaxErrorBodySize is the maximum allowed size of an error-response body.
	// The limit of 1 MB is considered to be greatly sufficient.
	MaxErrorBodySize = megaByte
	// MaxConfigBodySize is the maximum allowed size of a config blob.
	// The limit of 4 MB is considered to be greatly sufficient.
	MaxConfigBodySize = 4 * megaByte
	// MaxOpenShiftStatusBody is the maximum allowed size of an OpenShift status body.
	// The limit of 4 MB is considered to be greatly sufficient.
	MaxOpenShiftStatusBody = 4 * megaByte
	// MaxTarFileManifestSize is the maximum allowed size of a (docker save)-like manifest (which may contain multiple images)
	// The limit of 1 MB is considered to be greatly sufficient.
	MaxTarFileManifestSize = megaByte
)

All constants below are intended to be used as limits for `ReadAtMost`. The immediate use-case for limiting the size of in-memory copied data is to protect against OOM DOS attacks as described inCVE-2020-1702. Instead of copying data until running out of memory, we error out after hitting the specified limit.

Functions

func ReadAtMost

func ReadAtMost(reader io.Reader, limit int) ([]byte, error)

ReadAtMost reads from reader and errors out if the specified limit (in bytes) is exceeded.