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-rw-r--r--main.c0
-rw-r--r--set1.h0
-rw-r--r--task1_hex_to_base64.c364
-rw-r--r--task2_fixed_xor.c0
4 files changed, 0 insertions, 364 deletions
diff --git a/main.c b/main.c
deleted file mode 100644
index e69de29..0000000
--- a/main.c
+++ /dev/null
diff --git a/set1.h b/set1.h
deleted file mode 100644
index e69de29..0000000
--- a/set1.h
+++ /dev/null
diff --git a/task1_hex_to_base64.c b/task1_hex_to_base64.c
deleted file mode 100644
index 8e19f74..0000000
--- a/task1_hex_to_base64.c
+++ /dev/null
@@ -1,364 +0,0 @@
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <ctype.h>
-
-static const unsigned char base64_encode[] =
- "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
- "abcdefghijklmnopqrstuvwxyz"
- "0123456789+/";
-
-static const unsigned char hex_encode[] =
- "0123456789abcdef";
-
-/*
- * This functions accepts a string and returns it base64 encoded
-*/
-void three_bytes_to_base64(char * encode, int bytes_to_print, char *result)
-{
- unsigned char one, two, three, four;
- unsigned char tmp;
- char ret[4];
-
- // first six bits
- one = encode[0] >> 2;
- ret[0] = base64_encode[one];
- if(bytes_to_print-- > 0)
- result[0] = ret[0];
- // second six bits
- // two last bits of first byte
- tmp = encode[0] & 0x03;
- two = encode[1] >> 4;
- tmp = tmp << 4;
- two = tmp | two;
- ret[1] = base64_encode[two];
- if(bytes_to_print-- > 0)
- result[1] = ret[1];
- // second six bits
- // two last bits of first byte
- // third six bits
- tmp = encode[1] & 0x0F;
- tmp = tmp << 2;
- three = encode[2] & 0xC0;
- three = three >> 6;
- three = tmp | three;
- ret[2] = base64_encode[three];
- if(bytes_to_print-- > 0)
- result[2] = ret[2];
- // last six bit11s
- four = encode[2] & 0x3F;
- ret[3] = base64_encode[four];
- ret[4] = '\0';
- if(bytes_to_print-- > 0)
- result[3] = ret[3];
- }
-
-
-
-
-static char string_to_hex_map[] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
- 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D,
- 0x0E, 0x0F};
-/*
- * This function converts the first char of a string into its corresponding
- * hex value
- *
- * @return On Sucess return 0, if char is no valid hex value returns -1
- */
-int hex_char_to_bit(char toEncode)
-{
- char encode;
- switch(toEncode) {
- case '0':
- encode = string_to_hex_map[0];
- break;
- case '1':
- encode = string_to_hex_map[1];
- break;
- case '2':
- encode = string_to_hex_map[2];
- break;
- case '3':
- encode = string_to_hex_map[3];
- break;
- case '4':
- encode = string_to_hex_map[4];
- break;
- case '5':
- encode = string_to_hex_map[5];
- break;
- case '6':
- encode = string_to_hex_map[6];
- break;
- case '7':
- encode = string_to_hex_map[7];
- break;
- case '8':
- encode = string_to_hex_map[8];
- break;
- case '9':
- encode = string_to_hex_map[9];
- break;
- case 'a':
- encode = string_to_hex_map[10];
- break;
- case 'b':
- encode = string_to_hex_map[11];
- break;
- case 'c':
- encode = string_to_hex_map[12];
- break;
- case 'd':
- encode = string_to_hex_map[13];
- break;
- case 'e':
- encode = string_to_hex_map[14];
- break;
- case 'f':
- encode = string_to_hex_map[15];
- break;
- default:
- return -1;
- }
-
- return encode;
-
-}
-
-
-void two_char_hex(char *start, char *result)
-{
- char first = hex_char_to_bit(start[0]);
- char second = hex_char_to_bit(start[1]);
-
- *result = first;
- *result = *result << 4;
- *result = *result | second;
-}
-
-int convert_hex_string_to_character_string(char *encode, char* result)
-{
- int i;
- int length = strlen(encode);
-
- for(i = 0;i< length/2;i++)
- two_char_hex(&encode[i*2], &result[i]);
-
- return i;
-}
-
-int convert_to_base64(char *encode, char *result)
-{
- int length = strlen(encode);
-
- int rounds = length / 3;
- int bytes_last_round = length % 3;
- int i;
-
- for (i=0;i<rounds;i++) {
- three_bytes_to_base64(encode + i*3,4, &result[i*4]);
- }
- // in der letzen runde nicht mehr alle ausgeben
- // nur noch 3-leftover
- if (bytes_last_round > 0) {
- three_bytes_to_base64(encode + i*3, 1+bytes_last_round, &result[i*4]);
-
- for(i=0;i<(3-bytes_last_round);i++)
- result[i*4+(1+bytes_last_round)] = '=';
- }
-
-}
-
-void xor_string(char *str1, char *key, char *result)
-{
- int i, j;
- int length_key = strlen(key);
-
- for(i=0, j=0;i<strlen(str1);i++,j++) {
- if (j >= length_key)
- j = 0;
-
- result[i] = str1[i] ^ key[j];
- }
-}
-
-void xor_string_equal_length(char *str1, char* str2, char *result, int length) {
- int i;
-
- for(i=0;i<length;i++)
- result[i] = str1[i] ^ str2[i];
-
- return;
-
-}
-
-
-void xor_string_single_byte(char byte, char* string, char *result, int length) {
- int i;
-
- for(i=0;i<length;i++)
- result[i] = string[i] ^ byte;
-
- result[i] = '\0';
-
- return;
-}
-
-/**
- * results must be to times bigger than str1
- */
-void hex_binary_to_string(char *str1, char *result, int length)
-{
- int i;
- int tmp = 0;
-
- for(i=0;i<length/2;i++) {
- tmp = str1[i] & 0xF0;
- tmp = tmp >> 4;
- result[i*2] = hex_encode[tmp];
- tmp = str1[i] & 0x0F;
- result[(i*2)+1] = hex_encode[tmp];
- }
-
- result[i*2] = '\0';
-}
-
-
-
-int score_based_on_frequent_characters(char *string, int length)
-{
- int number = 0;
- int i;
- char tmp;
-
- for(i=0;i<length;i++) {
- tmp = tolower(string[i]);
- if( tmp == 'e' || tmp == 'a' || tmp == 'i' || tmp == 'o'
- || tmp == 'u' )
- number++;
- }
-
- return ((number*100)/length);
-}
-
-int isprintable(char *string, int length)
-{
- int i;
-
- for(i=0;i<length;i++) {
- if(!(isprint(string[i]) || isspace(string[i]))) {
- return 0;
- }
- }
-
- return 1;
-}
-
-void string_looks_like_it_is_english(char *string, int length)
-{
- char *xor_tmp = malloc(strlen(string));
- int i;
-
- for(i= 0; i< 255; i++) {
- xor_string_single_byte((char) i, string, xor_tmp, length);
- if (!isprintable(xor_tmp, length))
- continue;
- int score = score_based_on_frequent_characters(xor_tmp, length);
- if(score > 20)
- printf("char: %c, score: %i, string: %s\n", (char) i, score, xor_tmp);
- }
-
- //free(xor_tmp);
-}
-
-void task4() {
- /** read the file */
- FILE *fp;
- int bytes_read;
- int malloc_size = 62;
- int line_number = 0;
- int j;
- char *string = malloc(malloc_size);
- char *string2 = malloc(malloc_size);
-
- fp = fopen("4.txt", "r");
-
- if (fp == NULL) {
- printf("Error open file\n");
- exit(1);
- }
-
- while (fscanf(fp, "%61c", string) != EOF) {
- j = convert_hex_string_to_character_string(string, string2);
- printf("line number: %i, length: %i,\n", line_number, j);
- string_looks_like_it_is_english(string2, j);
- line_number++;
- }
-
- fclose(fp);
-
-}
-
-void task5()
-{
- char *stanze = "Burning 'em, if you ain't quick and nimble\nI go crazy when I hear a cymbal";
-
- //printf("%s\n", stanze);
- char *result = malloc(strlen(stanze));
- char *printable = malloc(strlen(stanze)*5);
- xor_string(stanze, "ICE", result);
- hex_binary_to_string(result, printable, 2*strlen(stanze));
- printf("%s\n", printable);
-}
-
-
-int main(int argc, char **argv)
-{
- if (argc == 3 ) {
- int length = strlen(argv[1]);
- char *tmp = malloc(length);
- char *tmp2 = malloc(length);
- char *base64= malloc(length);
- char *__xor_string = malloc(length);
- char *back_hex = malloc(length);
- int i = convert_hex_string_to_character_string(argv[1], tmp);
- int j = convert_hex_string_to_character_string(argv[2], tmp2);
- xor_string_equal_length(tmp, tmp2, __xor_string, strlen(argv[2]));
- // convert the __xor_string to printable charaters
- hex_binary_to_string(tmp2, back_hex, strlen(argv[2]));
- printf("***************************\n");
- printf("set 1, challelnge 1:\n");
- printf("input string 1:\n");
- printf("%s\n", argv[1]);
- printf("input string 2:\n");
- printf("%s\n", argv[2]);
-
- printf("char string of arg 1:\n");
- printf("%s\n", tmp);
- printf("char string of arg 2:\n");
- printf("%s\n", tmp2);
-
- printf("string 2 from hex back to printable charaters:\n");
- printf("%s\n", back_hex);
- printf("***************************\n");
- printf("set 1, challenge 2\n");
- printf("xor string:\n");
- hex_binary_to_string(__xor_string, back_hex, strlen(argv[2]));
- printf("%s\n", back_hex);
-
- printf("***************************\n");
- printf("set 1, challenge 3\n");
- //string_looks_
-
- }
-/*
- printf("***************************\n");
- printf("set 1, challenge 4\n");
- task4();
-*/
- //printf("***************************\n");
- //printf("set 1, challenge 5\n");
- task5();
-
-
-}
diff --git a/task2_fixed_xor.c b/task2_fixed_xor.c
deleted file mode 100644
index e69de29..0000000
--- a/task2_fixed_xor.c
+++ /dev/null
generated by cgit v1.2.3-70-g09d2 (git 2.52.0) at 2025-12-08 19:07:36 +0000