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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// terms that can be accessed at https://unidoc.io/eula/

package crypt ;import (_e "crypto/aes";_ae "crypto/cipher";_dd "crypto/md5";_ef "crypto/rand";_a "crypto/rc4";_g "fmt";_dg "github.com/unidoc/unipdf/v3/common";_af "github.com/unidoc/unipdf/v3/core/security";_f "io";);func init (){_ecd ("\u0041\u0045\u0053V\u0032",_cd )};
func (filterAES )EncryptBytes (buf []byte ,okey []byte )([]byte ,error ){_bg ,_eg :=_e .NewCipher (okey );if _eg !=nil {return nil ,_eg ;};_dg .Log .Trace ("A\u0045\u0053\u0020\u0045nc\u0072y\u0070\u0074\u0020\u0028\u0025d\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );
const _aec =_e .BlockSize ;_fea :=_aec -len (buf )%_aec ;for _eb :=0;_eb < _fea ;_eb ++{buf =append (buf ,byte (_fea ));};_dg .Log .Trace ("\u0050a\u0064d\u0065\u0064\u0020\u0074\u006f \u0025\u0064 \u0062\u0079\u0074\u0065\u0073",len (buf ));_gc :=make ([]byte ,_aec +len (buf ));
_bf :=_gc [:_aec ];if _ ,_ga :=_f .ReadFull (_ef .Reader ,_bf );_ga !=nil {return nil ,_ga ;};_ddf :=_ae .NewCBCEncrypter (_bg ,_bf );_ddf .CryptBlocks (_gc [_aec :],buf );buf =_gc ;_dg .Log .Trace ("\u0074\u006f\u0020(\u0025\u0064\u0029\u003a\u0020\u0025\u0020\u0078",len (buf ),buf );
return buf ,nil ;};func _aea (_dbc FilterDict )(Filter ,error ){if _dbc .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",_dbc .Length );
};if _dbc .Length < 5||_dbc .Length > 16{if _dbc .Length ==40||_dbc .Length ==64||_dbc .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",_dbc .Length );
_dbc .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",_dbc .Length );
};};return filterV2 {_add :_dbc .Length },nil ;};var _ Filter =filterV2 {};

// NewFilter creates CryptFilter from a corresponding dictionary.
func NewFilter (d FilterDict )(Filter ,error ){_bfc ,_dge :=_cgc (d .CFM );if _dge !=nil {return nil ,_dge ;};_afe ,_dge :=_bfc (d );if _dge !=nil {return nil ,_dge ;};return _afe ,nil ;};var _ Filter =filterAESV2 {};

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

// Name implements Filter interface.
func (filterV2 )Name ()string {return "\u0056\u0032"};func (filterIdentity )KeyLength ()int {return 0};type filterIdentity struct{};func init (){_ecd ("\u0041\u0045\u0053V\u0033",_db )};

// Name implements Filter interface.
func (filterAESV2 )Name ()string {return "\u0041\u0045\u0053V\u0032"};func (filterIdentity )EncryptBytes (p []byte ,okey []byte )([]byte ,error ){return p ,nil };

// MakeKey implements Filter interface.
func (filterAESV2 )MakeKey (objNum ,genNum uint32 ,ekey []byte )([]byte ,error ){return _df (objNum ,genNum ,ekey ,true );};

// PDFVersion implements Filter interface.
func (filterAESV2 )PDFVersion ()[2]int {return [2]int {1,5}};func (filterIdentity )HandlerVersion ()(V ,R int ){return ;};type filterV2 struct{_add int };func _cd (_fe FilterDict )(Filter ,error ){if _fe .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",_fe .Length );
_fe .Length /=8;};if _fe .Length !=0&&_fe .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",_fe .Length );
};return filterAESV2 {},nil ;};

// PDFVersion implements Filter interface.
func (filterAESV3 )PDFVersion ()[2]int {return [2]int {2,0}};func _db (_bd FilterDict )(Filter ,error ){if _bd .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",_bd .Length );
_bd .Length /=8;};if _bd .Length !=0&&_bd .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",_bd .Length );
};return filterAESV3 {},nil ;};

// 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 (_bfe ,_aef uint32 ,_ba []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 (_ca []byte ,_cdf []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 (_cg []byte ,_ddd []byte )([]byte ,error );};

// FilterDict represents information from a CryptFilter dictionary.
type FilterDict struct{CFM string ;AuthEvent _af .AuthEvent ;Length int ;};func init (){_ecd ("\u0056\u0032",_aea )};

// MakeKey implements Filter interface.
func (_cdd filterV2 )MakeKey (objNum ,genNum uint32 ,ekey []byte )([]byte ,error ){return _df (objNum ,genNum ,ekey ,false );};var _ Filter =filterAESV3 {};

// KeyLength implements Filter interface.
func (_adb filterV2 )KeyLength ()int {return _adb ._add };

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

// NewFilterAESV3 creates an AES-based filter with a 256 bit key (AESV3).
func NewFilterAESV3 ()Filter {_b ,_bc :=_db (FilterDict {});if _bc !=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",_bc );
return filterAESV3 {};};return _b ;};

// HandlerVersion implements Filter interface.
func (_ged filterV2 )HandlerVersion ()(V ,R int ){V ,R =2,3;return ;};type filterAES struct{};

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

// EncryptBytes implements Filter interface.
func (filterV2 )EncryptBytes (buf []byte ,okey []byte )([]byte ,error ){_cb ,_ecg :=_a .NewCipher (okey );if _ecg !=nil {return nil ,_ecg ;};_dg .Log .Trace ("\u0052\u00434\u0020\u0045\u006ec\u0072\u0079\u0070\u0074\u003a\u0020\u0025\u0020\u0078",buf );
_cb .XORKeyStream (buf ,buf );_dg .Log .Trace ("\u0074o\u003a\u0020\u0025\u0020\u0078",buf );return buf ,nil ;};

// MakeKey implements Filter interface.
func (filterAESV3 )MakeKey (_ ,_ uint32 ,ekey []byte )([]byte ,error ){return ekey ,nil };type filterFunc func (_cde FilterDict )(Filter ,error );func (filterIdentity )DecryptBytes (p []byte ,okey []byte )([]byte ,error ){return p ,nil };func (filterIdentity )MakeKey (objNum ,genNum uint32 ,fkey []byte )([]byte ,error ){return fkey ,nil };
func (filterAES )DecryptBytes (buf []byte ,okey []byte )([]byte ,error ){_gce ,_afa :=_e .NewCipher (okey );if _afa !=nil {return nil ,_afa ;};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 ));};_dga :=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 (_dga ),_dga );
_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 ));
};_feaf :=_ae .NewCBCDecrypter (_gce ,_dga );_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 );
_feaf .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 ;};_gg :=int (buf [len (buf )-1]);if _gg > 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",_gg ,len (buf ));
return buf ,_g .Errorf ("\u0069n\u0076a\u006c\u0069\u0064\u0020\u0070a\u0064\u0020l\u0065\u006e\u0067\u0074\u0068");};buf =buf [:len (buf )-_gg ];return buf ,nil ;};

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

// NewFilterAESV2 creates an AES-based filter with a 128 bit key (AESV2).
func NewFilterAESV2 ()Filter {_c ,_fc :=_cd (FilterDict {});if _fc !=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",_fc );
return filterAESV2 {};};return _c ;};func _df (_geg ,_ggc uint32 ,_fed []byte ,_afg bool )([]byte ,error ){_dee :=make ([]byte ,len (_fed )+5);copy (_dee ,_fed );for _ad :=0;_ad < 3;_ad ++{_be :=byte ((_geg >>uint32 (8*_ad ))&0xff);_dee [_ad +len (_fed )]=_be ;
};for _ed :=0;_ed < 2;_ed ++{_ebc :=byte ((_ggc >>uint32 (8*_ed ))&0xff);_dee [_ed +len (_fed )+3]=_ebc ;};if _afg {_dee =append (_dee ,0x73);_dee =append (_dee ,0x41);_dee =append (_dee ,0x6C);_dee =append (_dee ,0x54);};_bfa :=_dd .New ();_bfa .Write (_dee );
_cc :=_bfa .Sum (nil );if len (_fed )+5< 16{return _cc [0:len (_fed )+5],nil ;};return _cc ,nil ;};

// HandlerVersion implements Filter interface.
func (filterAESV2 )HandlerVersion ()(V ,R int ){V ,R =4,4;return ;};func _ecd (_gcd string ,_afed filterFunc ){if _ ,_afd :=_gf [_gcd ];_afd {panic ("\u0061l\u0072e\u0061\u0064\u0079\u0020\u0072e\u0067\u0069s\u0074\u0065\u0072\u0065\u0064");};_gf [_gcd ]=_afed ;
};

// KeyLength implements Filter interface.
func (filterAESV2 )KeyLength ()int {return 128/8};func (filterIdentity )Name ()string {return "\u0049\u0064\u0065\u006e\u0074\u0069\u0074\u0079"};func (filterIdentity )PDFVersion ()[2]int {return [2]int {}};func _cgc (_gag string )(filterFunc ,error ){_ebb :=_gf [_gag ];
if _ebb ==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",_gag );};return _ebb ,nil ;};var (_gf =make (map[string ]filterFunc );
);type filterAESV2 struct{filterAES };type filterAESV3 struct{filterAES };

// NewFilterV2 creates a RC4-based filter with a specified key length (in bytes).
func NewFilterV2 (length int )Filter {_ge ,_ee :=_aea (FilterDict {Length :length });if _ee !=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",_ee );
return filterV2 {_add :length };};return _ge ;};

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