Compute

Computes the PDF encryption data.

Table of contents

Namespace: Com\Tecnick\Pdf\Encrypt

abstract class Compute extends Data

Extends: Data

Source: src/Compute.php:38

Computes the PDF encryption data.

Methods

encrypt()

Encrypt data using the specified encrypt type.

public encrypt(
    int|string $type,
    string $data = '',
    string $key = '',
    int $objnum = 0,
    int $gennum = 0
): string

Parameters:

  • $type (int|string): Encrypt type.
  • $data (string): Data string to encrypt.
  • $key (string): Encryption key.
  • $objnum (int): Object number.
  • $gennum (int): Object generation number.

Returns: string

Throws:

Source: src/Compute.php:51

getEncPermissionsString()

Convert encryption P value to a string of bytes, low-order byte first.

public getEncPermissionsString(int $protection): string

Parameters:

  • $protection (int): 32bit encryption permission value (P value).

Returns: string

Source: src/Compute.php:239

getObjectKey()

Compute encryption key depending on object number where the encrypted data is stored.

This is used for all strings and streams without crypt filter specifier.

public getObjectKey(int $objnum, int $gennum = 0): string

Parameters:

  • $objnum (int): Object number.
  • $gennum (int): Object generation number.

Returns: string

Throws:

  • Exception: When either number is out of range.

Source: src/Compute.php:211

getPubKeyPermissionsString()

Convert encryption P value to the four bytes carried by a public-key recipient envelope, high-order byte first.

The byte order is the opposite of the /P key material of getEncPermissionsString().

public getPubKeyPermissionsString(int $protection): string

Parameters:

  • $protection (int): 32bit encryption permission value (P value).

Returns: string

Source: src/Compute.php:253

getUserPermissionCode()

Return the permission code used on encryption (P value).

The returned value is a signed 32-bit integer as required by Table 22: reserved bits 7, 8 and 13 to 32 are set, bits 1 and 2 are clear, and every granted permission bit is set.

public getUserPermissionCode(string[] $permissions, int $mode): int

Parameters:

  • $permissions (string[]): The set of permissions (specify the ones you want to block).
  • $mode (int): Encryption strength: 0 = RC4-40 (deprecated); 1 = RC4-128 (deprecated); 2 = AES-128; 3 = AES-256 R5; 4 = AES-256 R6 (PDF 2.0 / ISO 32000-2). Revision 2 defines fewer permission bits than the others.

Returns: int

Throws:

  • Exception: When a permission name is not recognised.

Source: src/Compute.php:285

Inherited members

From Data

  • DEFAULTPERMS: Permission set applied when the caller does not choose one.

From Output