From 1cd2b4cafa4bb22004b85fc783111803f20e5f2e Mon Sep 17 00:00:00 2001
From: Tomasz Sowa <t.sowa@ttmath.org>
Date: Fri, 28 Oct 2022 14:18:18 +0200
Subject: [PATCH] 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
---
 src/base64.cpp | 76 +++++++++++++++++--------------------------
 src/base64.h   | 87 +++++++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 112 insertions(+), 51 deletions(-)

diff --git a/src/base64.cpp b/src/base64.cpp
index 8f7deb0..deec14e 100644
--- a/src/base64.cpp
+++ b/src/base64.cpp
@@ -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
diff --git a/src/base64.h b/src/base64.h
index 8b53e24..a70885d 100644
--- a/src/base64.h
+++ b/src/base64.h
@@ -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