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base64: add possibility for the decoding strings to not have padding characters 

Add Base64::RequirePaddingOnDecodedStrings(bool) method.

while here:
- add Decode(...) methods taking wide characters as the input string
This commit is contained in:
Tomasz Sowa 2022-10-28 14:18:18 +02:00
parent a3438f4ae0
commit 1cd2b4cafa
2 changed files with 112 additions and 51 deletions
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76
src/base64.cpp
View File

@ -5,7 +5,7 @@
*/
/*
* Copyright (c) 2012, Tomasz Sowa
* Copyright (c) 2012-2022, Tomasz Sowa
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -50,6 +50,7 @@ Base64::Base64()
padding = '=';
tabbase64_len = 64;
not_existing = 256; // first 8 bits are zero
require_padding_on_decoded_strings = true;
}
@ -64,6 +65,14 @@ void Base64::SetPadding(char c)
}
void Base64::RequirePaddingOnDecodedStrings(bool require)
{
this->require_padding_on_decoded_strings = require;
}
void Base64::Convert3to4Pieces(const char * s, size_t len, unsigned int * tab4)
{
const unsigned char * tab3 = reinterpret_cast<const unsigned char*>(s);
@ -155,20 +164,6 @@ bool Base64::CharFromBase64(unsigned int from, unsigned int & to)
bool Base64::Make4pieces(const char * s, unsigned int * tab4)
{
for(size_t i=0 ; i<4 ; ++i)
{
if( s[i] == padding )
tab4[i] = not_existing;
else
if( !CharFromBase64(s[i], tab4[i]) )
return false;
}
return true;
}
@ -185,15 +180,6 @@ void Base64::Save4PiecesToString(std::string & s, const unsigned int * tab4)
void Base64::Save3PiecesToString(std::string & s, const unsigned int * tab3)
{
for(int i=0 ; i<3 ; ++i)
{
if( tab3[i] != not_existing )
s += tab3[i];
}
}
@ -229,31 +215,9 @@ void Base64::Encode(const std::string & in, std::string & out)
bool Base64::Decode(const char * in, size_t len, std::string & out)
{
unsigned int tab3[3];
unsigned int tab4[4];
out.clear();
size_t new_size = len - len/3 + 3;
out.reserve(new_size);
if( len % 4 != 0 )
return false;
for(size_t i=0 ; i<len ; i+=4)
{
if( !Make4pieces(in+i, tab4) )
return false;
ConvertFrom4to3Pieces(tab4, tab3);
Save3PiecesToString(out, tab3);
}
return true;
return DecodeRaw(in, len, out);
}
@ -270,6 +234,24 @@ bool Base64::Decode(const std::string & in, std::string & out)
}
bool Base64::Decode(const wchar_t * in, size_t len, std::string & out)
{
return DecodeRaw(in, len, out);
}
bool Base64::Decode(const wchar_t * in, std::string & out)
{
size_t len = wcslen(in);
return Decode(in, len, out);
}
bool Base64::Decode(const std::wstring & in, std::string & out)
{
return Decode(in.c_str(), in.size(), out);
}
} // namespace Tito

87
src/base64.h
View File

@ -5,7 +5,7 @@
*/
/*
* Copyright (c) 2012, Tomasz Sowa
* Copyright (c) 2012-2022, Tomasz Sowa
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -48,9 +48,18 @@ public:
Base64();
// default '=';
/*
* padding character
* default '=';
*/
void SetPadding(char c);
/*
* if false then allow the strings passed to Decode(...) methods to now have the trailing padding characters ('=')
* default: true
*/
void RequirePaddingOnDecodedStrings(bool require);
void Encode(const char * in, size_t len, std::string & out);
void Encode(const char * in, std::string & out);
void Encode(const std::string & in, std::string & out);
@ -59,6 +68,9 @@ public:
bool Decode(const char * in, std::string & out);
bool Decode(const std::string & in, std::string & out);
bool Decode(const wchar_t * in, size_t len, std::string & out);
bool Decode(const wchar_t * in, std::string & out);
bool Decode(const std::wstring & in, std::string & out);
private:
@ -67,17 +79,84 @@ private:
size_t tabbase64_len;
char padding;
unsigned int not_existing;
bool require_padding_on_decoded_strings;
void Convert3to4Pieces(const char * s, size_t len, unsigned int * tab4);
void ConvertFrom4to3Pieces(const unsigned int * tab4, unsigned int * tab3);
bool CharFromBase64(unsigned int from, unsigned int & to);
bool Make4pieces(const char * s, unsigned int * tab4);
void Save4PiecesToString(std::string & s, const unsigned int * tab4);
void Save3PiecesToString(std::string & s, const unsigned int * tab3);
template<typename CharType>
bool Make4pieces(const CharType * s, size_t len, unsigned int * tab4);
template<typename StringType>
void Save3PiecesToString(const unsigned int * tab3, StringType & s);
template<typename CharType, typename StringType>
bool DecodeRaw(const CharType * in, size_t len, StringType & out);
};
template<typename CharType>
bool Base64::Make4pieces(const CharType * s, size_t len, unsigned int * tab4)
{
for(size_t i=0 ; i<4 ; ++i)
{
if( i >= len || s[i] == padding )
tab4[i] = not_existing;
else
if( !CharFromBase64(static_cast<unsigned int>(s[i]), tab4[i]) )
return false;
}
return true;
}
template<typename StringType>
void Base64::Save3PiecesToString(const unsigned int * tab3, StringType & s)
{
for(int i=0 ; i<3 ; ++i)
{
if( tab3[i] != not_existing )
s += tab3[i];
}
}
template<typename CharType, typename StringType>
bool Base64::DecodeRaw(const CharType * in, size_t len, StringType & out)
{
unsigned int tab3[3];
unsigned int tab4[4];
out.clear();
size_t new_size = len - len/3 + 3;
out.reserve(new_size);
if( require_padding_on_decoded_strings && len % 4 != 0 )
return false;
while( len > 0 )
{
if( !Make4pieces(in, len, tab4) )
return false;
ConvertFrom4to3Pieces(tab4, tab3);
Save3PiecesToString(tab3, out);
in += 4;
len = (len >= 4) ? len - 4 : 0;
}
return true;
}
} // namespace Tito