github.com/unidoc/unipdf/v3@v3.55.0/core/security/crypt/crypt.go

//
// Copyright 2020 FoxyUtils ehf. All rights reserved.
//
// This is a commercial product and requires a license to operate.
// A trial license can be obtained at https://unidoc.io
//
// DO NOT EDIT: generated by unitwist Go source code obfuscator.
//
// Use of this source code is governed by the UniDoc End User License Agreement
// terms that can be accessed at https://unidoc.io/eula/

package crypt ;import (_a "crypto/aes";_fg "crypto/cipher";_ae "crypto/md5";_aa "crypto/rand";_d "crypto/rc4";_g "fmt";_dg "github.com/unidoc/unipdf/v3/common";_dc "github.com/unidoc/unipdf/v3/core/security";_e "io";);func init (){_gf ("\u0041\u0045\u0053V\u0032",_fc )};


// NewFilterV2 creates a RC4-based filter with a specified key length (in bytes).
func NewFilterV2 (length int )Filter {_abg ,_ea :=_gc (FilterDict {Length :length });if _ea !=nil {_dg .Log .Error ("E\u0052\u0052\u004f\u0052\u003a\u0020\u0063\u006f\u0075l\u0064\u0020\u006e\u006f\u0074\u0020\u0063re\u0061\u0074\u0065\u0020R\u0043\u0034\u0020\u0056\u0032\u0020\u0063\u0072\u0079pt\u0020\u0066i\u006c\u0074\u0065\u0072\u003a\u0020\u0025\u0076",_ea );
return filterV2 {_dbc :length };};return _abg ;};var _ Filter =filterAESV2 {};

// Filter is a common interface for crypt filter methods.
type Filter interface{

// Name returns a name of the filter that should be used in CFM field of Encrypt dictionary.
Name ()string ;

// KeyLength returns a length of the encryption key in bytes.
KeyLength ()int ;

// PDFVersion reports the minimal version of PDF document that introduced this filter.
PDFVersion ()[2]int ;

// HandlerVersion reports V and R parameters that should be used for this filter.
HandlerVersion ()(V ,R int );

// MakeKey generates a object encryption key based on file encryption key and object numbers.
// Used only for legacy filters - AESV3 doesn't change the key for each object.
MakeKey (_ecff ,_fde uint32 ,_eab []byte )([]byte ,error );

// EncryptBytes encrypts a buffer using object encryption key, as returned by MakeKey.
// Implementation may reuse a buffer and encrypt data in-place.
EncryptBytes (_bed []byte ,_dd []byte )([]byte ,error );

// DecryptBytes decrypts a buffer using object encryption key, as returned by MakeKey.
// Implementation may reuse a buffer and decrypt data in-place.
DecryptBytes (_de []byte ,_bdg []byte )([]byte ,error );};var _ Filter =filterV2 {};

// PDFVersion implements Filter interface.
func (filterAESV3 )PDFVersion ()[2]int {return [2]int {2,0}};

// KeyLength implements Filter interface.
func (_ee filterV2 )KeyLength ()int {return _ee ._dbc };func _gc (_bg FilterDict )(Filter ,error ){if _bg .Length %8!=0{return nil ,_g .Errorf ("\u0063\u0072\u0079p\u0074\u0020\u0066\u0069\u006c\u0074\u0065\u0072\u0020\u006c\u0065\u006e\u0067\u0074\u0068\u0020\u006e\u006f\u0074\u0020\u006d\u0075\u006c\u0074\u0069\u0070\u006c\u0065\u0020o\u0066\u0020\u0038\u0020\u0028\u0025\u0064\u0029",_bg .Length );
};if _bg .Length < 5||_bg .Length > 16{if _bg .Length ==40||_bg .Length ==64||_bg .Length ==128{_dg .Log .Debug ("\u0053\u0054\u0041\u004e\u0044AR\u0044\u0020V\u0049\u004f\u004c\u0041\u0054\u0049\u004f\u004e\u003a\u0020\u0043\u0072\u0079\u0070\u0074\u0020\u004c\u0065\u006e\u0067\u0074\u0068\u0020\u0061\u0070\u0070\u0065\u0061\u0072s\u0020\u0074\u006f \u0062\u0065\u0020\u0069\u006e\u0020\u0062\u0069\u0074\u0073\u0020\u0072\u0061t\u0068\u0065\u0072\u0020\u0074h\u0061\u006e\u0020\u0062\u0079\u0074\u0065\u0073\u0020-\u0020\u0061s\u0073u\u006d\u0069\u006e\u0067\u0020\u0062\u0069t\u0073\u0020\u0028\u0025\u0064\u0029",_bg .Length );
_bg .Length /=8;}else {return nil ,_g .Errorf ("\u0063\u0072\u0079\u0070\u0074\u0020\u0066\u0069\u006c\u0074\u0065\u0072\u0020\u006c\u0065\u006e\u0067\u0074h\u0020\u006e\u006f\u0074\u0020\u0069\u006e \u0072\u0061\u006e\u0067\u0065\u0020\u0034\u0030\u0020\u002d\u00201\u0032\u0038\u0020\u0062\u0069\u0074\u0020\u0028\u0025\u0064\u0029",_bg .Length );
};};return filterV2 {_dbc :_bg .Length },nil ;};type filterAES struct{};func _bgg (_aee ,_ga uint32 ,_bga []byte ,_bd bool )([]byte ,error ){_ecd :=make ([]byte ,len (_bga )+5);copy (_ecd ,_bga );for _cc :=0;_cc < 3;_cc ++{_ed :=byte ((_aee >>uint32 (8*_cc ))&0xff);
_ecd [_cc +len (_bga )]=_ed ;};for _ad :=0;_ad < 2;_ad ++{_adf :=byte ((_ga >>uint32 (8*_ad ))&0xff);_ecd [_ad +len (_bga )+3]=_adf ;};if _bd {_ecd =append (_ecd ,0x73);_ecd =append (_ecd ,0x41);_ecd =append (_ecd ,0x6C);_ecd =append (_ecd ,0x54);};_adc :=_ae .New ();
_adc .Write (_ecd );_cf :=_adc .Sum (nil );if len (_bga )+5< 16{return _cf [0:len (_bga )+5],nil ;};return _cf ,nil ;};func init (){_gf ("\u0041\u0045\u0053V\u0033",_ffb )};

// Name implements Filter interface.
func (filterV2 )Name ()string {return "\u0056\u0032"};type filterAESV2 struct{filterAES };var _ Filter =filterAESV3 {};

// HandlerVersion implements Filter interface.
func (_gcc filterV2 )HandlerVersion ()(V ,R int ){V ,R =2,3;return ;};type filterAESV3 struct{filterAES };func (filterAES )EncryptBytes (buf []byte ,okey []byte )([]byte ,error ){_db ,_be :=_a .NewCipher (okey );if _be !=nil {return nil ,_be ;};_dg .Log .Trace ("A\u0045\u0053\u0020\u0045nc\u0072y\u0070\u0074\u0020\u0028\u0025d\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );
const _df =_a .BlockSize ;_ebd :=_df -len (buf )%_df ;for _af :=0;_af < _ebd ;_af ++{buf =append (buf ,byte (_ebd ));};_dg .Log .Trace ("\u0050a\u0064d\u0065\u0064\u0020\u0074\u006f \u0025\u0064 \u0062\u0079\u0074\u0065\u0073",len (buf ));_aac :=make ([]byte ,_df +len (buf ));
_dgfc :=_aac [:_df ];if _ ,_c :=_e .ReadFull (_aa .Reader ,_dgfc );_c !=nil {return nil ,_c ;};_gd :=_fg .NewCBCEncrypter (_db ,_dgfc );_gd .CryptBlocks (_aac [_df :],buf );buf =_aac ;_dg .Log .Trace ("\u0074\u006f\u0020(\u0025\u0064\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );
return buf ,nil ;};

// NewIdentity creates an identity filter that bypasses all data without changes.
func NewIdentity ()Filter {return filterIdentity {}};

// HandlerVersion implements Filter interface.
func (filterAESV3 )HandlerVersion ()(V ,R int ){V ,R =5,6;return ;};

// HandlerVersion implements Filter interface.
func (filterAESV2 )HandlerVersion ()(V ,R int ){V ,R =4,4;return ;};func _fgeg (_afc string )(filterFunc ,error ){_aab :=_cce [_afc ];if _aab ==nil {return nil ,_g .Errorf ("\u0075\u006e\u0073\u0075p\u0070\u006f\u0072\u0074\u0065\u0064\u0020\u0063\u0072\u0079p\u0074 \u0066\u0069\u006c\u0074\u0065\u0072\u003a \u0025\u0071",_afc );
};return _aab ,nil ;};func (filterAES )DecryptBytes (buf []byte ,okey []byte )([]byte ,error ){_dbd ,_fa :=_a .NewCipher (okey );if _fa !=nil {return nil ,_fa ;};if len (buf )< 16{_dg .Log .Debug ("\u0045R\u0052\u004f\u0052\u0020\u0041\u0045\u0053\u0020\u0069\u006e\u0076a\u006c\u0069\u0064\u0020\u0062\u0075\u0066\u0020\u0025\u0073",buf );
return buf ,_g .Errorf ("\u0041\u0045\u0053\u003a B\u0075\u0066\u0020\u006c\u0065\u006e\u0020\u003c\u0020\u0031\u0036\u0020\u0028\u0025d\u0029",len (buf ));};_ebdc :=buf [:16];buf =buf [16:];if len (buf )%16!=0{_dg .Log .Debug ("\u0020\u0069\u0076\u0020\u0028\u0025\u0064\u0029\u003a\u0020\u0025\u0020\u0078",len (_ebdc ),_ebdc );
_dg .Log .Debug ("\u0062\u0075\u0066\u0020\u0028\u0025\u0064\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );return buf ,_g .Errorf ("\u0041\u0045\u0053\u0020\u0062\u0075\u0066\u0020\u006c\u0065\u006e\u0067\u0074\u0068\u0020\u006e\u006f\u0074\u0020\u006d\u0075\u006c\u0074\u0069p\u006c\u0065\u0020\u006f\u0066 \u0031\u0036 \u0028\u0025\u0064\u0029",len (buf ));
};_ec :=_fg .NewCBCDecrypter (_dbd ,_ebdc );_dg .Log .Trace ("A\u0045\u0053\u0020\u0044ec\u0072y\u0070\u0074\u0020\u0028\u0025d\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );_dg .Log .Trace ("\u0063\u0068\u006f\u0070\u0020\u0041\u0045\u0053\u0020\u0044\u0065c\u0072\u0079\u0070\u0074\u0020\u0028\u0025\u0064\u0029\u003a \u0025\u0020\u0078",len (buf ),buf );
_ec .CryptBlocks (buf ,buf );_dg .Log .Trace ("\u0074\u006f\u0020(\u0025\u0064\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );if len (buf )==0{_dg .Log .Trace ("\u0045\u006d\u0070\u0074\u0079\u0020b\u0075\u0066\u002c\u0020\u0072\u0065\u0074\u0075\u0072\u006e\u0069\u006e\u0067 \u0065\u006d\u0070\u0074\u0079\u0020\u0073t\u0072\u0069\u006e\u0067");
return buf ,nil ;};_fd :=int (buf [len (buf )-1]);if _fd > len (buf ){_dg .Log .Debug ("\u0049\u006c\u006c\u0065g\u0061\u006c\u0020\u0070\u0061\u0064\u0020\u006c\u0065\u006eg\u0074h\u0020\u0028\u0025\u0064\u0020\u003e\u0020%\u0064\u0029",_fd ,len (buf ));
return buf ,_g .Errorf ("\u0069n\u0076a\u006c\u0069\u0064\u0020\u0070a\u0064\u0020l\u0065\u006e\u0067\u0074\u0068");};buf =buf [:len (buf )-_fd ];return buf ,nil ;};

// NewFilterAESV2 creates an AES-based filter with a 128 bit key (AESV2).
func NewFilterAESV2 ()Filter {_dcb ,_eb :=_fc (FilterDict {});if _eb !=nil {_dg .Log .Error ("E\u0052\u0052\u004f\u0052\u003a\u0020\u0063\u006f\u0075l\u0064\u0020\u006e\u006f\u0074\u0020\u0063re\u0061\u0074\u0065\u0020A\u0045\u0053\u0020\u0056\u0032\u0020\u0063\u0072\u0079pt\u0020\u0066i\u006c\u0074\u0065\u0072\u003a\u0020\u0025\u0076",_eb );
return filterAESV2 {};};return _dcb ;};func init (){_gf ("\u0056\u0032",_gc )};func _gf (_gae string ,_fda filterFunc ){if _ ,_gcb :=_cce [_gae ];_gcb {panic ("\u0061l\u0072e\u0061\u0064\u0079\u0020\u0072e\u0067\u0069s\u0074\u0065\u0072\u0065\u0064");};
_cce [_gae ]=_fda ;};type filterIdentity struct{};

// MakeKey implements Filter interface.
func (filterAESV3 )MakeKey (_ ,_ uint32 ,ekey []byte )([]byte ,error ){return ekey ,nil };

// KeyLength implements Filter interface.
func (filterAESV3 )KeyLength ()int {return 256/8};

// KeyLength implements Filter interface.
func (filterAESV2 )KeyLength ()int {return 128/8};

// NewFilter creates CryptFilter from a corresponding dictionary.
func NewFilter (d FilterDict )(Filter ,error ){_dee ,_gcca :=_fgeg (d .CFM );if _gcca !=nil {return nil ,_gcca ;};_ag ,_gcca :=_dee (d );if _gcca !=nil {return nil ,_gcca ;};return _ag ,nil ;};type filterV2 struct{_dbc int };var (_cce =make (map[string ]filterFunc );
);func (filterIdentity )KeyLength ()int {return 0};

// Name implements Filter interface.
func (filterAESV2 )Name ()string {return "\u0041\u0045\u0053V\u0032"};type filterFunc func (_aef FilterDict )(Filter ,error );

// PDFVersion implements Filter interface.
func (_aae filterV2 )PDFVersion ()[2]int {return [2]int {}};func _fc (_ab FilterDict )(Filter ,error ){if _ab .Length ==128{_dg .Log .Debug ("\u0041\u0045S\u0056\u0032\u0020c\u0072\u0079\u0070\u0074\u0020f\u0069\u006c\u0074\u0065\u0072 l\u0065\u006e\u0067\u0074\u0068\u0020\u0061\u0070\u0070\u0065\u0061\u0072\u0073\u0020\u0074\u006f\u0020\u0062e\u0020i\u006e\u0020\u0062\u0069\u0074\u0073 ra\u0074\u0068\u0065\u0072\u0020\u0074\u0068\u0061\u006e\u0020\u0062\u0079te\u0073 \u002d\u0020\u0061\u0073s\u0075m\u0069n\u0067\u0020b\u0069\u0074s \u0028\u0025\u0064\u0029",_ab .Length );
_ab .Length /=8;};if _ab .Length !=0&&_ab .Length !=16{return nil ,_g .Errorf ("\u0069\u006e\u0076\u0061\u006c\u0069\u0064\u0020\u0041\u0045\u0053\u0056\u0032\u0020\u0063\u0072\u0079\u0070\u0074\u0020\u0066\u0069\u006c\u0074e\u0072\u0020\u006c\u0065\u006eg\u0074\u0068 \u0028\u0025\u0064\u0029",_ab .Length );
};return filterAESV2 {},nil ;};

// EncryptBytes implements Filter interface.
func (filterV2 )EncryptBytes (buf []byte ,okey []byte )([]byte ,error ){_gb ,_dbcb :=_d .NewCipher (okey );if _dbcb !=nil {return nil ,_dbcb ;};_dg .Log .Trace ("\u0052\u00434\u0020\u0045\u006ec\u0072\u0079\u0070\u0074\u003a\u0020\u0025\u0020\u0078",buf );
_gb .XORKeyStream (buf ,buf );_dg .Log .Trace ("\u0074o\u003a\u0020\u0025\u0020\u0078",buf );return buf ,nil ;};func (filterIdentity )MakeKey (objNum ,genNum uint32 ,fkey []byte )([]byte ,error ){return fkey ,nil };func (filterIdentity )EncryptBytes (p []byte ,okey []byte )([]byte ,error ){return p ,nil };


// FilterDict represents information from a CryptFilter dictionary.
type FilterDict struct{CFM string ;AuthEvent _dc .AuthEvent ;Length int ;};

// NewFilterAESV3 creates an AES-based filter with a 256 bit key (AESV3).
func NewFilterAESV3 ()Filter {_fcc ,_ff :=_ffb (FilterDict {});if _ff !=nil {_dg .Log .Error ("E\u0052\u0052\u004f\u0052\u003a\u0020\u0063\u006f\u0075l\u0064\u0020\u006e\u006f\u0074\u0020\u0063re\u0061\u0074\u0065\u0020A\u0045\u0053\u0020\u0056\u0033\u0020\u0063\u0072\u0079pt\u0020\u0066i\u006c\u0074\u0065\u0072\u003a\u0020\u0025\u0076",_ff );
return filterAESV3 {};};return _fcc ;};func (filterIdentity )PDFVersion ()[2]int {return [2]int {}};

// DecryptBytes implements Filter interface.
func (filterV2 )DecryptBytes (buf []byte ,okey []byte )([]byte ,error ){_ba ,_dbda :=_d .NewCipher (okey );if _dbda !=nil {return nil ,_dbda ;};_dg .Log .Trace ("\u0052\u00434\u0020\u0044\u0065c\u0072\u0079\u0070\u0074\u003a\u0020\u0025\u0020\u0078",buf );
_ba .XORKeyStream (buf ,buf );_dg .Log .Trace ("\u0074o\u003a\u0020\u0025\u0020\u0078",buf );return buf ,nil ;};

// MakeKey implements Filter interface.
func (filterAESV2 )MakeKey (objNum ,genNum uint32 ,ekey []byte )([]byte ,error ){return _bgg (objNum ,genNum ,ekey ,true );};func (filterIdentity )HandlerVersion ()(V ,R int ){return ;};func _ffb (_b FilterDict )(Filter ,error ){if _b .Length ==256{_dg .Log .Debug ("\u0041\u0045S\u0056\u0033\u0020c\u0072\u0079\u0070\u0074\u0020f\u0069\u006c\u0074\u0065\u0072 l\u0065\u006e\u0067\u0074\u0068\u0020\u0061\u0070\u0070\u0065\u0061\u0072\u0073\u0020\u0074\u006f\u0020\u0062e\u0020i\u006e\u0020\u0062\u0069\u0074\u0073 ra\u0074\u0068\u0065\u0072\u0020\u0074\u0068\u0061\u006e\u0020\u0062\u0079te\u0073 \u002d\u0020\u0061\u0073s\u0075m\u0069n\u0067\u0020b\u0069\u0074s \u0028\u0025\u0064\u0029",_b .Length );
_b .Length /=8;};if _b .Length !=0&&_b .Length !=32{return nil ,_g .Errorf ("\u0069\u006e\u0076\u0061\u006c\u0069\u0064\u0020\u0041\u0045\u0053\u0056\u0033\u0020\u0063\u0072\u0079\u0070\u0074\u0020\u0066\u0069\u006c\u0074e\u0072\u0020\u006c\u0065\u006eg\u0074\u0068 \u0028\u0025\u0064\u0029",_b .Length );
};return filterAESV3 {},nil ;};func (filterIdentity )Name ()string {return "\u0049\u0064\u0065\u006e\u0074\u0069\u0074\u0079"};

// PDFVersion implements Filter interface.
func (filterAESV2 )PDFVersion ()[2]int {return [2]int {1,5}};func (filterIdentity )DecryptBytes (p []byte ,okey []byte )([]byte ,error ){return p ,nil };

// Name implements Filter interface.
func (filterAESV3 )Name ()string {return "\u0041\u0045\u0053V\u0033"};

// MakeKey implements Filter interface.
func (_bef filterV2 )MakeKey (objNum ,genNum uint32 ,ekey []byte )([]byte ,error ){return _bgg (objNum ,genNum ,ekey ,false );};