unipdf/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.
//
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package crypt ;import (_e "crypto/aes";_c "crypto/cipher";_fd "crypto/md5";_fe "crypto/rand";_be "crypto/rc4";_f "fmt";_d "github.com/unidoc/unipdf/v3/common";_dd "github.com/unidoc/unipdf/v3/core/security";_b "io";);func init (){_dff ("\u0041\u0045\u0053V\u0032",_bec )};

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

// 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 (_ge ,_bfga uint32 ,_gab []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 (_gdf []byte ,_fbg []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 (_fec []byte ,_db []byte )([]byte ,error );};

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

// Name implements Filter interface.
func (filterV2 )Name ()string {return "\u0056\u0032"};

// HandlerVersion implements Filter interface.
func (_dde filterV2 )HandlerVersion ()(V ,R int ){V ,R =2,3;return ;};func _ff (_ab FilterDict )(Filter ,error ){if _ab .Length %8!=0{return nil ,_f .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",_ab .Length );};if _ab .Length < 5||_ab .Length > 16{if _ab .Length ==40||_ab .Length ==64||_ab .Length ==128{_d .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",_ab .Length );_ab .Length /=8;}else {return nil ,_f .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",_ab .Length );};};return filterV2 {_ed :_ab .Length },nil ;};type filterAESV2 struct{filterAES };func (filterIdentity )DecryptBytes (p []byte ,okey []byte )([]byte ,error ){return p ,nil };

// DecryptBytes implements Filter interface.
func (filterV2 )DecryptBytes (buf []byte ,okey []byte )([]byte ,error ){_ea ,_gge :=_be .NewCipher (okey );if _gge !=nil {return nil ,_gge ;};_d .Log .Trace ("\u0052\u00434\u0020\u0044\u0065c\u0072\u0079\u0070\u0074\u003a\u0020\u0025\u0020\u0078",buf );_ea .XORKeyStream (buf ,buf );_d .Log .Trace ("\u0074o\u003a\u0020\u0025\u0020\u0078",buf );return buf ,nil ;};func init (){_dff ("\u0041\u0045\u0053V\u0033",_da )};func (filterAES )DecryptBytes (buf []byte ,okey []byte )([]byte ,error ){_bc ,_cg :=_e .NewCipher (okey );if _cg !=nil {return nil ,_cg ;};if len (buf )< 16{_d .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 ,_f .Errorf ("\u0041\u0045\u0053\u003a B\u0075\u0066\u0020\u006c\u0065\u006e\u0020\u003c\u0020\u0031\u0036\u0020\u0028\u0025d\u0029",len (buf ));};_af :=buf [:16];buf =buf [16:];if len (buf )%16!=0{_d .Log .Debug ("\u0020\u0069\u0076\u0020\u0028\u0025\u0064\u0029\u003a\u0020\u0025\u0020\u0078",len (_af ),_af );_d .Log .Debug ("\u0062\u0075\u0066\u0020\u0028\u0025\u0064\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );return buf ,_f .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 ));};_bfd :=_c .NewCBCDecrypter (_bc ,_af );_d .Log .Trace ("A\u0045\u0053\u0020\u0044ec\u0072y\u0070\u0074\u0020\u0028\u0025d\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );_d .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 );_bfd .CryptBlocks (buf ,buf );_d .Log .Trace ("\u0074\u006f\u0020(\u0025\u0064\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );if len (buf )==0{_d .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 ;};_dg :=int (buf [len (buf )-1]);if _dg > len (buf ){_d .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",_dg ,len (buf ));return buf ,_f .Errorf ("\u0069n\u0076a\u006c\u0069\u0064\u0020\u0070a\u0064\u0020l\u0065\u006e\u0067\u0074\u0068");};buf =buf [:len (buf )-_dg ];return buf ,nil ;};func (filterIdentity )HandlerVersion ()(V ,R int ){return ;};type filterAESV3 struct{filterAES };

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

// PDFVersion implements Filter interface.
func (filterAESV3 )PDFVersion ()[2]int {return [2]int {2,0}};func (filterAES )EncryptBytes (buf []byte ,okey []byte )([]byte ,error ){_fda ,_fc :=_e .NewCipher (okey );if _fc !=nil {return nil ,_fc ;};_d .Log .Trace ("A\u0045\u0053\u0020\u0045nc\u0072y\u0070\u0074\u0020\u0028\u0025d\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );const _ga =_e .BlockSize ;_fb :=_ga -len (buf )%_ga ;for _bfg :=0;_bfg < _fb ;_bfg ++{buf =append (buf ,byte (_fb ));};_d .Log .Trace ("\u0050a\u0064d\u0065\u0064\u0020\u0074\u006f \u0025\u0064 \u0062\u0079\u0074\u0065\u0073",len (buf ));_cfd :=make ([]byte ,_ga +len (buf ));_bb :=_cfd [:_ga ];if _ ,_bg :=_b .ReadFull (_fe .Reader ,_bb );_bg !=nil {return nil ,_bg ;};_ddd :=_c .NewCBCEncrypter (_fda ,_bb );_ddd .CryptBlocks (_cfd [_ga :],buf );buf =_cfd ;_d .Log .Trace ("\u0074\u006f\u0020(\u0025\u0064\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );return buf ,nil ;};

// Name implements Filter interface.
func (filterAESV2 )Name ()string {return "\u0041\u0045\u0053V\u0032"};func _bec (_df FilterDict )(Filter ,error ){if _df .Length ==128{_d .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",_df .Length );_df .Length /=8;};if _df .Length !=0&&_df .Length !=16{return nil ,_f .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",_df .Length );};return filterAESV2 {},nil ;};

// NewFilterAESV3 creates an AES-based filter with a 256 bit key (AESV3).
func NewFilterAESV3 ()Filter {_eb ,_gd :=_da (FilterDict {});if _gd !=nil {_d .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",_gd );return filterAESV3 {};};return _eb ;};func _fff (_bbg ,_bgb uint32 ,_ceb []byte ,_bbc bool )([]byte ,error ){_beb :=make ([]byte ,len (_ceb )+5);for _dgb :=0;_dgb < len (_ceb );_dgb ++{_beb [_dgb ]=_ceb [_dgb ];};for _abe :=0;_abe < 3;_abe ++{_cd :=byte ((_bbg >>uint32 (8*_abe ))&0xff);_beb [_abe +len (_ceb )]=_cd ;};for _ba :=0;_ba < 2;_ba ++{_ae :=byte ((_bgb >>uint32 (8*_ba ))&0xff);_beb [_ba +len (_ceb )+3]=_ae ;};if _bbc {_beb =append (_beb ,0x73);_beb =append (_beb ,0x41);_beb =append (_beb ,0x6C);_beb =append (_beb ,0x54);};_cebb :=_fd .New ();_cebb .Write (_beb );_ca :=_cebb .Sum (nil );if len (_ceb )+5< 16{return _ca [0:len (_ceb )+5],nil ;};return _ca ,nil ;};

// KeyLength implements Filter interface.
func (filterAESV3 )KeyLength ()int {return 256/8};func (filterIdentity )KeyLength ()int {return 0};func init (){_dff ("\u0056\u0032",_ff )};func _dff (_gfb string ,_cef filterFunc ){if _ ,_bfc :=_agb [_gfb ];_bfc {panic ("\u0061l\u0072e\u0061\u0064\u0079\u0020\u0072e\u0067\u0069s\u0074\u0065\u0072\u0065\u0064");};_agb [_gfb ]=_cef ;};var _ Filter =filterAESV3 {};var _ Filter =filterAESV2 {};

// MakeKey implements Filter interface.
func (filterAESV2 )MakeKey (objNum ,genNum uint32 ,ekey []byte )([]byte ,error ){return _fff (objNum ,genNum ,ekey ,true );};func (filterIdentity )Name ()string {return "\u0049\u0064\u0065\u006e\u0074\u0069\u0074\u0079"};

// EncryptBytes implements Filter interface.
func (filterV2 )EncryptBytes (buf []byte ,okey []byte )([]byte ,error ){_beg ,_gg :=_be .NewCipher (okey );if _gg !=nil {return nil ,_gg ;};_d .Log .Trace ("\u0052\u00434\u0020\u0045\u006ec\u0072\u0079\u0070\u0074\u003a\u0020\u0025\u0020\u0078",buf );_beg .XORKeyStream (buf ,buf );_d .Log .Trace ("\u0074o\u003a\u0020\u0025\u0020\u0078",buf );return buf ,nil ;};type filterAES struct{};type filterIdentity struct{};

// FilterDict represents information from a CryptFilter dictionary.
type FilterDict struct{CFM string ;AuthEvent _dd .AuthEvent ;Length int ;};func (filterIdentity )MakeKey (objNum ,genNum uint32 ,fkey []byte )([]byte ,error ){return fkey ,nil };var (_agb =make (map[string ]filterFunc ););

// HandlerVersion implements Filter interface.
func (filterAESV2 )HandlerVersion ()(V ,R int ){V ,R =4,4;return ;};func (filterIdentity )PDFVersion ()[2]int {return [2]int {}};

// PDFVersion implements Filter interface.
func (filterAESV2 )PDFVersion ()[2]int {return [2]int {1,5}};func _da (_ad FilterDict )(Filter ,error ){if _ad .Length ==256{_d .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",_ad .Length );_ad .Length /=8;};if _ad .Length !=0&&_ad .Length !=32{return nil ,_f .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",_ad .Length );};return filterAESV3 {},nil ;};type filterV2 struct{_ed int };type filterFunc func (_de FilterDict )(Filter ,error );

// NewFilter creates CryptFilter from a corresponding dictionary.
func NewFilter (d FilterDict )(Filter ,error ){_ffa ,_adf :=_dgg (d .CFM );if _adf !=nil {return nil ,_adf ;};_gf ,_adf :=_ffa (d );if _adf !=nil {return nil ,_adf ;};return _gf ,nil ;};var _ Filter =filterV2 {};

// NewFilterV2 creates a RC4-based filter with a specified key length (in bytes).
func NewFilterV2 (length int )Filter {_cea ,_cbd :=_ff (FilterDict {Length :length });if _cbd !=nil {_d .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",_cbd );return filterV2 {_ed :length };};return _cea ;};

// NewFilterAESV2 creates an AES-based filter with a 128 bit key (AESV2).
func NewFilterAESV2 ()Filter {_cf ,_gc :=_bec (FilterDict {});if _gc !=nil {_d .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",_gc );return filterAESV2 {};};return _cf ;};

// PDFVersion implements Filter interface.
func (_ec filterV2 )PDFVersion ()[2]int {return [2]int {}};

// MakeKey implements Filter interface.
func (_cgg filterV2 )MakeKey (objNum ,genNum uint32 ,ekey []byte )([]byte ,error ){return _fff (objNum ,genNum ,ekey ,false );};func (filterIdentity )EncryptBytes (p []byte ,okey []byte )([]byte ,error ){return p ,nil };

// HandlerVersion implements Filter interface.
func (filterAESV3 )HandlerVersion ()(V ,R int ){V ,R =5,6;return ;};func _dgg (_eg string )(filterFunc ,error ){_cbdb :=_agb [string (_eg )];if _cbdb ==nil {return nil ,_f .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",_eg );};return _cbdb ,nil ;};

// KeyLength implements Filter interface.
func (_bce filterV2 )KeyLength ()int {return _bce ._ed };

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