Set 1/A1

Makefile

@@ -0,0 +1,5 @@
+all:
+	gcc -g -c utils/hex_to_base64.cpp -o obj/hex_to_base64.o
+	gcc -g -c utils/utils_tester.cpp -o obj/utils_tester.o
+	gcc -g -o utils_tester obj/hex_to_base64.o obj/utils_tester.o
+	

utils/hex_to_base64.cpp

@@ -0,0 +1,135 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MIN(a,b) a<b ? a : b
+
+unsigned short char_to_hex[256] = { 
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+	// 50
+	0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
+	0x0f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a, 0x0b, 0x0c,
+    0x0d, 0x0e, 0x0f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+
+	// 100: this rest shouldn't be needed 
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+unsigned char int_to_base64[65] = {
+	'A','B','C','D','E','F','G','H','I','J',
+	'K','L','M','N','O','P','Q','R','S','T',
+	'U','V','W','X','Y','Z','a','b','c','d',
+	'e','f','g','h','i','j','k','l','m','n',
+	'o','p','q','r','s','t','u','v','w','x',
+	'y','z','0','1','2','3','4','5','6','7',
+	'8','9','+','/','='
+};
+
+// data stores 24 bits
+struct int24 {
+	unsigned int data:24;
+};
+
+void read_bytes(const char* hex_buff, int24& o_data, unsigned len=3)
+{
+	unsigned char hex;
+	for(int i=0; i<len; ++i)
+	{
+		o_data.data <<= 8;
+
+		hex  = char_to_hex[ hex_buff[0+(i*2)] ] * 16;
+		hex += char_to_hex[ hex_buff[1+(i*2)] ];
+		o_data.data |= hex;
+	}
+}
+
+/* -----------------------------------------------------------------------------
+ * @brief   Converts HEX to Base64      
+ *          
+ * @param   hex_buf     : 	buffer with hexes to be converted
+ *			base64_buff :	output buffer. has to be \0 initialized
+ *			hex_buff_len: 	length of hex_buff
+ *          
+ * @returns number of characters written to base64_buf
+ *
+ * @remarks remarks 
+ *
+ *------------------------------------------------------------------------------ */
+unsigned hex_to_base64(const char* hex_buff, char*& base64_buff, unsigned hex_buff_len ) 
+{		
+	unsigned j=0;
+	const unsigned unaligned = hex_buff_len % 6;	
+	unsigned len_aligned = hex_buff_len - unaligned;
+
+	int24 data;
+	unsigned char idx1,idx2,idx3,idx4;
+	for(unsigned i=0; i<len_aligned; i+=6) 
+	{
+		data.data = 0;
+		read_bytes(hex_buff+i, data, 3);
+
+		idx1 = 0x3F & (data.data >> 6*3);
+		idx2 = 0x3F & (data.data >> 6*2);
+		idx3 = 0x3F & (data.data >> 6);
+		idx4 = 0x3F & data.data;
+
+		base64_buff[j++] = int_to_base64[idx1];
+		base64_buff[j++] = int_to_base64[idx2];
+		base64_buff[j++] = int_to_base64[idx3];
+		base64_buff[j++] = int_to_base64[idx4];
+	}
+
+	if(unaligned)
+	{
+		const unsigned rest_bytes = unaligned/2;
+		data.data = 0;
+		read_bytes(hex_buff+len_aligned, data, rest_bytes);
+
+		if(rest_bytes==1)
+		{
+			if( ( data.data & (data.data & 0x3F) ) == data.data)
+			{
+				base64_buff[j++] = int_to_base64[ data.data ];	
+			}
+			else
+			{
+				idx1 =(data.data >> 2 ) & 0x3F;
+				idx2 = data.data & 0x3;
+				base64_buff[j++] = int_to_base64[ idx1 ];
+				base64_buff[j++] = int_to_base64[ idx2 ];
+			}
+		}
+		else if(rest_bytes==2)
+		{
+			idx1 =(data.data >> 10 ) & 0x3F;
+			idx2 =(data.data >>  4 ) & 0x3F;
+			idx3 =(data.data ) & 15;
+
+			base64_buff[j++] = int_to_base64[ idx1 ];
+			base64_buff[j++] = int_to_base64[ idx2 ];
+			base64_buff[j++] = int_to_base64[ idx3 ];
+		}
+	}
+	return j;
+}

utils/hex_to_base64.h

@@ -0,0 +1 @@
+unsigned hex_to_base64(const char* hex_buff, char*& base64_buff, unsigned hex_buff_len );

utils/utils_tester.cpp

@@ -0,0 +1,49 @@
+#include "hex_to_base64.h"
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+
+void hex_to_base64_text() {
+	const char test_buff1[]		="49276d206b696c6c696e6720796f757220627261696e206c696b65206120706f69736f6e6f7573206d757368726f6f6d"; 
+	const char expected_buff1[]	="SSdtIGtpbGxpbmcgeW91ciBicmFpbiBsaWtlIGEgcG9pc29ub3VzIG11c2hyb29t";
+
+	const char test_buff2[]		="4927"; 
+	const char expected_buff2[]	="SSH";
+
+	const char test_buff3[]		="49"; 
+	const char expected_buff3[]	="SB";
+
+	const char test_buff4[]		="33"; 
+	const char expected_buff4[]	="z";
+
+	char output[256];
+	char* po=output;
+
+	memset (output,'\0', 256);
+	hex_to_base64(test_buff1, po, strlen(test_buff1) );
+//	printf("%s\n", output);
+	assert( memcmp(expected_buff1, output, strlen(expected_buff1)) == 0 );
+	assert( strlen(expected_buff1) == strlen(output));
+	
+	// test case  when there are 2 hex'es
+	memset (output,'\0', 256);
+	hex_to_base64(test_buff2, po, strlen(test_buff2) );
+	assert( memcmp(expected_buff2, output, strlen(expected_buff2)) == 0 );
+	assert( strlen(expected_buff2) == strlen(output));
+
+	// test case  when there is 1 hex
+	memset (output,'\0', 256);
+	hex_to_base64(test_buff3, po, strlen(test_buff3) );
+	assert( memcmp(expected_buff3, output, strlen(expected_buff3)) == 0 );
+	assert( strlen(expected_buff3) == strlen(output));
+
+	// test case  when there is 1 char
+	memset (output,'\0', 256);
+	hex_to_base64(test_buff4, po, strlen(test_buff4) );
+	assert( memcmp(expected_buff4, output, strlen(expected_buff4)) == 0 );
+	assert( strlen(expected_buff4) == strlen(output));
+}
+
+int main() {
+	hex_to_base64_text();
+}