Module org.sejda.sambox

Package org.sejda.sambox.pdmodel.encryption

Class StandardSecurityHandler

java.lang.Object

org.sejda.sambox.pdmodel.encryption.SecurityHandler

org.sejda.sambox.pdmodel.encryption.StandardSecurityHandler

public final class StandardSecurityHandler
extends SecurityHandler

The standard security handler. This security handler protects document with password.

See Also:

• to see how to protect document with this security handler.

Field Summary

Fields

Modifier and Type	Field	Description
private static final byte[]	ENCRYPT_PADDING	Standard padding for encryption.
static final String	FILTER	Type of security handler.
private static final String[]	HASHES_2B
private static final org.slf4j.Logger	LOG
static final Class<?>	PROTECTION_POLICY_CLASS	Protection policy class for this handler.

Fields inherited from class org.sejda.sambox.pdmodel.encryption.SecurityHandler

keyLength

Constructor Summary

Constructors

Constructor	Description
StandardSecurityHandler()	Constructor.

Method Summary

Modifier and Type	Method	Description
byte[]	computeEncryptedKey(byte[] password, byte[] o, byte[] u, byte[] oe, byte[] ue, int permissions, byte[] id, int encRevision, int length, boolean encryptMetadata, boolean isOwnerPassword)	Compute the encryption key.
private byte[]	computeEncryptedKeyRev234(byte[] password, byte[] o, int permissions, byte[] id, boolean encryptMetadata, int length, int encRevision)
private byte[]	computeEncryptedKeyRev56(byte[] password, boolean isOwnerPassword, byte[] o, byte[] u, byte[] oe, byte[] ue, int encRevision)
private byte[]	computeHash2A(byte[] password, byte[] salt, byte[] u)
private static byte[]	computeHash2B(byte[] input, byte[] password, byte[] userKey)
byte[]	computeOwnerPassword(byte[] ownerPassword, byte[] userPassword, int encRevision, int length)	Compute the owner entry in the encryption dictionary.
private byte[]	computeRC4key(byte[] ownerPassword, int encRevision, int length)
private static byte[]	computeSHA256(byte[] input, byte[] password, byte[] userKey)
byte[]	computeUserPassword(byte[] password, byte[] owner, int permissions, byte[] id, int encRevision, int length, boolean encryptMetadata)	This will compute the user password hash.
private static byte[]	concat(byte[] a, byte[] b, byte[] c)
private byte[]	getDocumentIDBytes(COSArray documentIDArray)
byte[]	getUserPassword(byte[] ownerPassword, byte[] owner, int encRevision, int length)	Get the user password based on the owner password.
boolean	isOwnerPassword(byte[] ownerPassword, byte[] user, byte[] owner, int permissions, byte[] id, int encRevision, int length, boolean encryptMetadata)	Check for owner password.
boolean	isOwnerPassword(String password, byte[] user, byte[] owner, int permissions, byte[] id, int encRevision, int length, boolean encryptMetadata)	Check for owner password.
boolean	isUserPassword(byte[] password, byte[] user, byte[] owner, int permissions, byte[] id, int encRevision, int length, boolean encryptMetadata)	Check if a plaintext password is the user password.
boolean	isUserPassword(String password, byte[] user, byte[] owner, int permissions, byte[] id, int encRevision, int length, boolean encryptMetadata)	Check if a plaintext password is the user password.
void	prepareForDecryption(PDEncryption encryption, COSArray documentIDArray, DecryptionMaterial decryptionMaterial)	Prepares everything to decrypt the document.
private static byte[]	truncate127(byte[] in)
private byte[]	truncateOrPad(byte[] password)	This will take the password and truncate or pad it as necessary.
private void	validatePerms(PDEncryption encryption, int dicPermissions, boolean encryptMetadata)

Methods inherited from class org.sejda.sambox.pdmodel.encryption.SecurityHandler

decrypt, decryptDataRC4, decryptDataRC4, decryptStream, getCurrentAccessPermission, getEncryptionKey, getKeyLength, isAES, isDecryptMetadata, setAES, setCurrentAccessPermission, setDecryptMetadata, setEncryptionKey, setKeyLength, setStreamFilterName, setStringFilterName

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

LOG

private static final org.slf4j.Logger LOG

FILTER

public static final String FILTER

Type of security handler.

See Also:

• Constant Field Values

PROTECTION_POLICY_CLASS

public static final Class<?> PROTECTION_POLICY_CLASS

Protection policy class for this handler.

ENCRYPT_PADDING

private static final byte[] ENCRYPT_PADDING

Standard padding for encryption.

HASHES_2B

private static final String[] HASHES_2B

Constructor Details

StandardSecurityHandler

public StandardSecurityHandler()

Constructor.

Method Details

prepareForDecryption

public void prepareForDecryption(PDEncryption encryption,
 COSArray documentIDArray,
 DecryptionMaterial decryptionMaterial)
                          throws InvalidPasswordException,
IOException

Prepares everything to decrypt the document.

Only if decryption of single objects is needed this should be called.

Specified by:

prepareForDecryption in class SecurityHandler

Parameters:

encryption - encryption dictionary

documentIDArray - document id

decryptionMaterial - Information used to decrypt the document.

Throws:

InvalidPasswordException - If the password is incorrect.

IOException - If there is an error accessing data.

getDocumentIDBytes

private byte[] getDocumentIDBytes(COSArray documentIDArray)

validatePerms

private void validatePerms(PDEncryption encryption,
 int dicPermissions,
 boolean encryptMetadata)
                    throws IOException

Throws:

IOException

isOwnerPassword

public boolean isOwnerPassword(byte[] ownerPassword,
 byte[] user,
 byte[] owner,
 int permissions,
 byte[] id,
 int encRevision,
 int length,
 boolean encryptMetadata)
                        throws IOException

Check for owner password.

Parameters:

ownerPassword - The owner password.

user - The u entry of the encryption dictionary.

owner - The o entry of the encryption dictionary.

permissions - The set of permissions on the document.

id - The document id.

encRevision - The encryption algorithm revision.

length - The encryption key length.

encryptMetadata - The encryption metadata

Returns:

True If the ownerPassword param is the owner password.

Throws:

IOException - If there is an error accessing data.

getUserPassword

public byte[] getUserPassword(byte[] ownerPassword,
 byte[] owner,
 int encRevision,
 int length)
                       throws IOException

Get the user password based on the owner password.

Parameters:

ownerPassword - The plaintext owner password.

owner - The o entry of the encryption dictionary.

encRevision - The encryption revision number.

length - The key length.

Returns:

The u entry of the encryption dictionary.

Throws:

IOException - If there is an error accessing data while generating the user password.

computeEncryptedKey

public byte[] computeEncryptedKey(byte[] password,
 byte[] o,
 byte[] u,
 byte[] oe,
 byte[] ue,
 int permissions,
 byte[] id,
 int encRevision,
 int length,
 boolean encryptMetadata,
 boolean isOwnerPassword)
                           throws IOException

Compute the encryption key.

Parameters:

password - The password to compute the encrypted key.

o - The O entry of the encryption dictionary.

u - The U entry of the encryption dictionary.

oe - The OE entry of the encryption dictionary.

ue - The UE entry of the encryption dictionary.

permissions - The permissions for the document.

id - The document id.

encRevision - The revision of the encryption algorithm.

length - The length of the encryption key.

encryptMetadata - The encryption metadata

isOwnerPassword - whether the password given is the owner password (for revision 6)

Returns:

The encrypted key bytes.

Throws:

IOException - If there is an error with encryption.

computeEncryptedKeyRev234

private byte[] computeEncryptedKeyRev234(byte[] password,
 byte[] o,
 int permissions,
 byte[] id,
 boolean encryptMetadata,
 int length,
 int encRevision)

computeEncryptedKeyRev56

private byte[] computeEncryptedKeyRev56(byte[] password,
 boolean isOwnerPassword,
 byte[] o,
 byte[] u,
 byte[] oe,
 byte[] ue,
 int encRevision)
                                 throws IOException

Throws:

IOException

computeUserPassword

public byte[] computeUserPassword(byte[] password,
 byte[] owner,
 int permissions,
 byte[] id,
 int encRevision,
 int length,
 boolean encryptMetadata)
                           throws IOException

This will compute the user password hash.

Parameters:

password - The plain text password.

owner - The owner password hash.

permissions - The document permissions.

id - The document id.

encRevision - The revision of the encryption.

length - The length of the encryption key.

encryptMetadata - The encryption metadata

Returns:

The user password.

Throws:

IOException - if the password could not be computed

computeOwnerPassword

public byte[] computeOwnerPassword(byte[] ownerPassword,
 byte[] userPassword,
 int encRevision,
 int length)
                            throws IOException

Compute the owner entry in the encryption dictionary.

Parameters:

ownerPassword - The plaintext owner password.

userPassword - The plaintext user password.

encRevision - The revision number of the encryption algorithm.

length - The length of the encryption key.

Returns:

The o entry of the encryption dictionary.

Throws:

IOException - if the owner password could not be computed

computeRC4key

private byte[] computeRC4key(byte[] ownerPassword,
 int encRevision,
 int length)

truncateOrPad

private byte[] truncateOrPad(byte[] password)

This will take the password and truncate or pad it as necessary.

Parameters:

password - The password to pad or truncate.

Returns:

The padded or truncated password.

isUserPassword

public boolean isUserPassword(byte[] password,
 byte[] user,
 byte[] owner,
 int permissions,
 byte[] id,
 int encRevision,
 int length,
 boolean encryptMetadata)
                       throws IOException

Check if a plaintext password is the user password.

Parameters:

password - The plaintext password.

user - The u entry of the encryption dictionary.

owner - The o entry of the encryption dictionary.

permissions - The permissions set in the PDF.

id - The document id used for encryption.

encRevision - The revision of the encryption algorithm.

length - The length of the encryption key.

encryptMetadata - The encryption metadata

Returns:

true If the plaintext password is the user password.

Throws:

IOException - If there is an error accessing data.

isUserPassword

public boolean isUserPassword(String password,
 byte[] user,
 byte[] owner,
 int permissions,
 byte[] id,
 int encRevision,
 int length,
 boolean encryptMetadata)
                       throws IOException

Check if a plaintext password is the user password.

Parameters:

password - The plaintext password.

user - The u entry of the encryption dictionary.

owner - The o entry of the encryption dictionary.

permissions - The permissions set in the PDF.

id - The document id used for encryption.

encRevision - The revision of the encryption algorithm.

length - The length of the encryption key.

encryptMetadata - The encryption metadata

Returns:

true If the plaintext password is the user password.

Throws:

IOException - If there is an error accessing data.

isOwnerPassword

public boolean isOwnerPassword(String password,
 byte[] user,
 byte[] owner,
 int permissions,
 byte[] id,
 int encRevision,
 int length,
 boolean encryptMetadata)
                        throws IOException

Check for owner password.

Parameters:

password - The owner password.

user - The u entry of the encryption dictionary.

owner - The o entry of the encryption dictionary.

permissions - The set of permissions on the document.

id - The document id.

encRevision - The encryption algorithm revision.

length - The encryption key length.

encryptMetadata - The encryption metadata

Returns:

True If the ownerPassword param is the owner password.

Throws:

IOException - If there is an error accessing data.

computeHash2A

private byte[] computeHash2A(byte[] password,
 byte[] salt,
 byte[] u)
                      throws IOException

Throws:

IOException

computeHash2B

private static byte[] computeHash2B(byte[] input,
 byte[] password,
 byte[] userKey)
                             throws IOException

Throws:

IOException

computeSHA256

private static byte[] computeSHA256(byte[] input,
 byte[] password,
 byte[] userKey)

concat

private static byte[] concat(byte[] a,
 byte[] b,
 byte[] c)

truncate127

private static byte[] truncate127(byte[] in)