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base64.c
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base64.c
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//=================================================_
// Base64 Encoding and Decoding Tool |_
// Author: @SynActktraa [Mikey] |_
// (Cli Wizard) base64 algorithm implemented in C. |_
// © This tool is based on ASCII charset. |_
//=======================================================
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "utils.h"
void encode(char* plaintext, char* flag, char* out){
int buffer_len;
buffer_len = Strlen(plaintext);
// calculates space for base64 encoded string
int base64_val_space = (0.4*(buffer_len+1))+buffer_len+2;
// calculates space for binary dump of input string
int bin_dump_space = (buffer_len * 8)+1;
char six_bit_bin[7], Ox49_val_bin[9];
char *base64_val = (char*)malloc(sizeof(char) * base64_val_space);
char *bin_dump = (char*)malloc(sizeof(char) * bin_dump_space);
int i, j, k, bin_dump_len;
memset(Ox49_val_bin, 0, Strlen(Ox49_val_bin));
memset(bin_dump, 0, Strlen(bin_dump));
for( i=0; plaintext[i] != '\0'; ++i ) {
/*
charValidate checks for non-ascii characters
*/
if( charValidate(plaintext[i]) == -1 ){
fprintf(stderr, "InputError: can't take non-ascii characters");
putchar(ch);
exit(1);
}
strcpy(Ox49_val_bin, decToBin(plaintext[i]));
while( Strlen(Ox49_val_bin)%8 != 0 ){
/*
checks for 8 bit binary, if not it starts
adding zeroes from the 0th index until it's
8 bit binary value.
*/
k = insert(Ox49_val_bin, 0, '0', Strlen(Ox49_val_bin), Strlen(Ox49_val_bin)+1);
Ox49_val_bin[k] = '\0';
}
//concatenates the 8 bit binary in bin_dump to create
//a binary dump which will be manipulated later
strcat(bin_dump, Ox49_val_bin);
memset(Ox49_val_bin, 0, Strlen(Ox49_val_bin));
}
if(!strcmp(flag, "-f"))
free(plaintext);
bin_dump_len = Strlen(bin_dump);
while( bin_dump_len%6 != 0 )
/*
checks if the length of binary dump is in the
multiplication of 6, coz base64 -> 2^6 = 64
*/
bin_dump_len = insert(bin_dump, bin_dump_len, '0', bin_dump_len, Strlen(bin_dump)+1);
i = 0, j = 0;
while( i[bin_dump]!='\0' ){
/*
moves 6 bits from bin_dump to six_bit_bin,
converts the 6 bit binary to decimal and stores
it in ascii_val and do some comparisions, then
adds accordingly and stores it in base64_val string
and increments i by 6.
*/
memset(six_bit_bin, 0, Strlen(six_bit_bin));
memmove(six_bit_bin, bin_dump+i, 6);
six_bit_bin[6] = 0;
int ascii_val = binToDec(six_bit_bin);
if( ascii_val>=0 && ascii_val<=25 )
base64_val[j] = ascii_val+65;
else if( ascii_val>=26 && ascii_val<=51 )
base64_val[j] = ascii_val+71;
else if( ascii_val>=52 && ascii_val<=61 )
base64_val[j] = ascii_val-4;
else if( ascii_val==62 )
base64_val[j] = ascii_val-19;
else if( ascii_val==63 )
base64_val[j] = ascii_val-16;
j++; i += 6;
}
base64_val[j] = '\0';
free(bin_dump);
while( Strlen(base64_val)%4 != 0 )
/*
inserts '=' at the end of the base64 encoded string until
the length is in the multiplication of 4.
*/
insert(base64_val, Strlen(base64_val), 0x3d, Strlen(base64_val), base64_val_space);
if ( out == NULL ){
/*
if outfile is not given, print the output
in cli/terminal
*/
fwrite(base64_val, 1, Strlen(base64_val), stdout);
putc(ch, stdout);
} else {
/*
else writes the ouput to the file
*/
FILE * fp = fopen(out, "w");
fputs(base64_val, fp);
}
free(base64_val);
}
void decode(char* base64_data, char* flag, char* out){
int i, j;
int buffer_len;
buffer_len = Strlen(base64_data);
// calculates space for base64 encoded string
int decData_val_space = (buffer_len+2)-(0.15*buffer_len);
// calculates space for binary dump of input string
int bin_dump_space = (buffer_len * 6)+1;
char Ox49_val_bin[9], byte_bin[9];
char *bin_dump = (char*)malloc(sizeof(char) * bin_dump_space);
char *decodeData = (char*)malloc(sizeof(char) * decData_val_space);
delspace(base64_data);
buffer_len = Strlen(base64_data);
while(*(base64_data+(buffer_len-1)) == '='){
/*
checks for '=' from the end of the input encoded string
and deletes the padding
*/
buffer_len = delete(base64_data, buffer_len-1, buffer_len);
}
memset(bin_dump, 0, Strlen(bin_dump));
memset(Ox49_val_bin, 0, Strlen(Ox49_val_bin));
for( i=0; base64_data[i]!=0; ++i ){
if (base64Validate(base64_data[i]) == -1) {
fprintf(stderr, "InputError: the string to be decoded is not correctly encoded");
putc(ch, stdout);
exit(1);
}
/*
checks for encoded data simultaneously, then subtracts
and evaluated decimal to binary function, then copies it
in Ox49_val_bin
*/
if( base64_data[i]>='B' && base64_data[i]<='Z' )
strcpy(Ox49_val_bin, decToBin(base64_data[i]-65));
else if( base64_data[i]>='a' && base64_data[i]<='z' )
strcpy(Ox49_val_bin, decToBin(base64_data[i]-71));
else if( base64_data[i]>='0' && base64_data[i]<='9' )
strcpy(Ox49_val_bin, decToBin(base64_data[i]+4));
else if( base64_data[i]=='+')
strcpy(Ox49_val_bin, decToBin(base64_data[i]+19) );
else if( base64_data[i]=='/' )
strcpy(Ox49_val_bin, decToBin(base64_data[i]+16) );
else if( base64_data[i] == 'A' )
strcpy(Ox49_val_bin, "000000");
int k = Strlen(Ox49_val_bin);
while( k%6 != 0 ){
/*
checks if the length of binary is in the
multiplication of 6, coz base64 -> 2^6 = 64
*/
k = insert(Ox49_val_bin, 0, '0', k, sizeof(Ox49_val_bin));
}
strcat(bin_dump, Ox49_val_bin);
memset(Ox49_val_bin, 0, Strlen(Ox49_val_bin));
}
if(!strcmp(flag, "-f"))
free(base64_data);
int bin_dump_len = Strlen(bin_dump);
while( bin_dump_len%8 != 0 ){
/*
checks for 8 bit binary, if not it starts
adding zeroes from the 0th index until it's
8 bit binary value.
*/
bin_dump_len = insert(bin_dump, bin_dump_len , '0', bin_dump_len, bin_dump_space);
}
*(bin_dump+bin_dump_len) = '\0';
i = 0, j = 0;
while( bin_dump[i]!='\0' ){
/*
moves 1 byte from bin_dump to byte_bin,
converts that byte binary to decimal and stores
it in decodeData and increments i by 8.
*/
memset(byte_bin, 0, Strlen(byte_bin));
memmove(byte_bin, bin_dump+i, 8);
byte_bin[8] = 0;
decodeData[j] = binToDec(byte_bin);
j++; i += 8;
}
decodeData[j] = '\0';
free(bin_dump);
if( out == NULL){
/*
if outfile is not given, print the output
in cli/terminal
*/
fwrite(decodeData, 1, Strlen(decodeData), stdout);
putc(ch, stdout);
} else {
/*
else writes the ouput to the file
*/
FILE * fp = fopen(out, "w");
fputs(decodeData, fp);
}
free(decodeData);
}
int main(int argc, char* argv[]){
char *string=NULL, *file=NULL, *out=NULL, *flag=NULL, *exe = basename(argv[0], slash);
int e_flag = 0, d_flag = 0, o_flag = 0, i_flag = 0, f_flag = 0,i = 0;
if ( argc==2 && !strcmp(argv[1], "-h") ) {
fprintf(stdout, "[Imp]: Put space separated data in quotes.\
\nUsage: %s [-e|-d] [-i|-f] [string|file]\n|CLI options|:-\
\n -e encodes the data string\
\n -d decodes the data string\
\n -i specify data string for manipulation\
\n -f specify filename for manipulation\
\n -o specify filename to store the result\
\n [if filename isn't specified, it defaults to base64Out]", exe);
putc(ch, stdout);
free(exe);
exe = NULL;
}else if ( argc >= 4 && argc <= 6 ) {
for(; i < argc; ++i){
if(!strcmp(argv[i], "-i")){
i_flag = 1;
flag="-i";
if( argv[i+1] == NULL ){
fprintf(stderr, "InputError: no data detected");
putc(ch, stdout);
return 1;
}
string = argv[i+1];
}
}
for(i=0; i < argc; ++i){
if(!strcmp(argv[i], "-f")){
f_flag = 1;
flag="-f";
if( argv[i+1] == NULL ){
fprintf(stderr, "FileError: no file detected");
putc(ch, stdout);
return 1;
}
file = argv[i+1];
}
}
if (!i_flag && !f_flag){
fprintf(stderr, "FlagError: data or file flag not detected");
putc(ch, stdout);
return 1;
}
if (i_flag && f_flag){
fprintf(stderr, "FlagError: can't manipulate two data at once.");
putc(ch, stdout);
return 1;
}
for(i = 0; i < argc; ++i) {
if(!strcmp(argv[i], "-e")){
e_flag += 1;
}
}
for(i = 0; i < argc; ++i) {
if(!strcmp(argv[i], "-d")){
d_flag += 1;
}
}
if(e_flag == 0 && d_flag == 0){
fprintf(stderr, "MethodError: conversion method not specified");
putc(ch, stdout);
return 1;
}
if(e_flag > 1 || d_flag > 1){
fprintf(stderr, "FlagError: can't use same flags more than once");
putc(ch, stdout);
return 1;
}
if(e_flag && d_flag){
fprintf(stderr, "MethodError: specify only one conversion method");
putc(ch, stdout);
return 1;
}
for( i = 0; i < argc; ++i) {
if(!strcmp(argv[i], "-o")) {
o_flag = 1;
if( argv[i+1] == NULL ){
out = "base64Out";
} else out = argv[i+1];
break;
}
}
if(o_flag == 0)
out=NULL;
if(f_flag){
string=retrieve(file);
}
if ( e_flag ) {
encode(string, flag, out);
} else if ( d_flag ) {
decode(string, flag, out);
}
} else {
fprintf(stderr, "\nUsage: %s -e/-d -i/-f <data>/<file>\
\nFor more, check help section:\
\n %s -h\n", exe, exe);
free(exe);
exe = NULL;
putc(ch, stdout);
}
free(exe);
exe = NULL;
return 0;
}
// https://dev.to/rdentato/utf-8-strings-in-c-1-3-42a4