security

Documentation

Index

• Constants
• type AuthEvent
• type Permissions
  • func (p Permissions) Allowed(p2 Permissions) bool
• type StdEncryptDict
• type StdHandler
  • func NewHandlerR4(id0 string, length int) StdHandler
  • func NewHandlerR6() StdHandler

Constants

const (
	// EventDocOpen is an event triggered when opening the document.
	EventDocOpen = AuthEvent("DocOpen")
	// EventEFOpen is an event triggered when accessing an embedded file.
	EventEFOpen = AuthEvent("EFOpen")
)

const (
	// PermOwner grants all permissions.
	PermOwner = Permissions(math.MaxUint32)

	// PermPrinting allows printing the document with a low quality.
	PermPrinting = Permissions(1 << 2)
	// PermModify allows to modify the document.
	PermModify = Permissions(1 << 3)
	// PermExtractGraphics allows to extract graphics from the document.
	PermExtractGraphics = Permissions(1 << 4)
	// PermAnnotate allows annotating the document.
	PermAnnotate = Permissions(1 << 5)
	// PermFillForms allow form filling, if annotation is disabled?  If annotation enabled, is not looked at.
	PermFillForms = Permissions(1 << 8)
	// PermDisabilityExtract allows to extract graphics in accessibility mode.
	PermDisabilityExtract = Permissions(1 << 9)
	// PermRotateInsert allows rotating, editing page order.
	PermRotateInsert = Permissions(1 << 10)
	// PermFullPrintQuality limits print quality (lowres), assuming Printing bit is set.
	PermFullPrintQuality = Permissions(1 << 11)
)

Types

type AuthEvent

type AuthEvent string

AuthEvent is an event type that triggers authentication.

type Permissions

type Permissions uint32

Permissions is a bitmask of access permissions for a PDF file.

func (Permissions) Allowed

func (p Permissions) Allowed(p2 Permissions) bool

Allowed checks if a set of permissions can be granted.

type StdEncryptDict

type StdEncryptDict struct {
	R int // (Required) A number specifying which revision of the standard security handler shall be used.

	P               Permissions
	EncryptMetadata bool // Indicates whether the document-level metadata stream shall be encrypted.

	O, U   []byte
	OE, UE []byte // R=6
	Perms  []byte // An encrypted copy of P (16 bytes). Used to verify permissions. R=6
}

StdEncryptDict is a set of additional fields used in standard encryption dictionary.

type StdHandler

type StdHandler interface {
	// GenerateParams uses owner and user passwords to set encryption parameters and generate an encryption key.
	// It assumes that R, P and EncryptMetadata are already set.
	GenerateParams(d *StdEncryptDict, ownerPass, userPass []byte) ([]byte, error)

	// Authenticate uses encryption dictionary parameters and the password to calculate
	// the document encryption key. It also returns permissions that should be granted to a user.
	// In case of failed authentication, it returns empty key and zero permissions with no error.
	Authenticate(d *StdEncryptDict, pass []byte) ([]byte, Permissions, error)
}

StdHandler is an interface for standard security handlers.

func NewHandlerR4

func NewHandlerR4(id0 string, length int) StdHandler

NewHandlerR4 creates a new standard security handler for R<=4.

func NewHandlerR6

func NewHandlerR6() StdHandler

NewHandlerR6 creates a new standard security handler for R=5 and R=6.