Initial commit of Troll Hunter challenge

archcloudlabs · Oct 2, 2019 · c6dc468 · c6dc468
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diff --git a/LICENSE b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2019 Jared
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/Makefile b/Makefile
@@ -0,0 +1,9 @@
+CC=gcc 
+FLAGS=-ggdb -O0 -m64
+
+release:
+	mkdir -p ./bin/
+	$(CC) $(FLAGS) ./src/main.c -o ./bin/dungeons_and_hackers-lvl-1
+
+clean:
+	rm ./bin/dungeons_and_hackers-lvl-1
diff --git a/README.md b/README.md
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+# Dungeons & Hackers: Troll Hunter
+Hack Fortress DEFCON 2019 RE challenge 1, "Troll Hunter".
+
+#### Requirements
+* gcc
+* make
+
+#### To Build
+```
+make
+```
+#### Walkthrough
+[Arch Cloud Labs' Walkthrough](https://www.archcloudlabs.com/re-1/)
diff --git a/src/main.c b/src/main.c
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+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+/**
+ *@brief get a random value via seed from /dev/urandom.
+ *@param N/A
+ *@return integer value
+ */
+int roll() 
+{
+    char *buff = (char *) malloc(100);
+    int fd = open("/dev/urandom", O_RDONLY);
+    read(fd, buff, 100);
+    close(fd);
+
+    srand( (int) buff);
+    int val = rand();
+    free(buff);
+
+    return val;
+}
+
+/**
+ *@brief XoR decode and print of char pointer
+ *@param [val] char pointer 
+ *@return N/A
+ */
+void decode(char *val) {
+
+    for (int i = 0; i < 22; i++) {
+        printf("%c",(val[i] ^ 51)); 
+    }
+    printf("\n");
+
+}
+
+int main(int argc, char *argv[])
+{
+
+    char *title = 
+    "██████╗ ██╗   ██╗███╗   ██╗ ██████╗ ███████╗ ██████╗ ███╗   ██╗███████╗       ██╗       ██╗  ██╗ █████╗  ██████╗██╗  ██╗███████╗██████╗ ███████╗\n"
+    "██╔══██╗██║   ██║████╗  ██║██╔════╝ ██╔════╝██╔═══██╗████╗  ██║██╔════╝       ██║       ██║  ██║██╔══██╗██╔════╝██║ ██╔╝██╔════╝██╔══██╗██╔════╝\n"
+    "██║  ██║██║   ██║██╔██╗ ██║██║  ███╗█████╗  ██║   ██║██╔██╗ ██║███████╗    ████████╗    ███████║███████║██║     █████╔╝ █████╗  ██████╔╝███████╗\n"
+    "██║  ██║██║   ██║██║╚██╗██║██║   ██║██╔══╝  ██║   ██║██║╚██╗██║╚════██║    ██╔═██╔═╝    ██╔══██║██╔══██║██║     ██╔═██╗ ██╔══╝  ██╔══██╗╚════██║\n"
+    "██████╔╝╚██████╔╝██║ ╚████║╚██████╔╝███████╗╚██████╔╝██║ ╚████║███████║    ██████║      ██║  ██║██║  ██║╚██████╗██║  ██╗███████╗██║  ██║███████║\n"
+    "╚═════╝  ╚═════╝ ╚═╝  ╚═══╝ ╚═════╝ ╚══════╝ ╚═════╝ ╚═╝  ╚═══╝╚══════╝    ╚═════╝      ╚═╝  ╚═╝╚═╝  ╚═╝ ╚═════╝╚═╝  ╚═╝╚══════╝╚═╝  ╚═╝╚══════╝\n";
+    printf("%s",title);
+    printf("\t\t\t\t\t\t\t[==== D&H Adventure Simulator - 3000 ====]\n");
+    printf("\t\t\t\t\t\t\t[=====     Troll Hunter Edition     =====]\n");
+
+    char hostname[200];
+    gethostname(hostname, 200);
+
+    //char *flag = "flag{troll_destroyer_!!}";
+    char *flag="U_RTHGA\\__lWV@GA\\JVAlN";
+    char *story = "You're venturing through the woods of memes. Suddenly a "\
+        "troll appears!\nA troll throws a mighty fist at your skull!\nAuto" \
+        "rolling to dodge!\n";
+
+    printf("[*] Welcome mighty challenger who hails from %s!\n", hostname);
+    printf("%s", story);
+
+    char buffer[10];
+    int num = roll(); // Value you're going to try to modify via r2
+    num = num % 20;
+
+    printf("\nClick to roll> ");
+    gets(buffer);
+    printf("\nYou auto rolled a %d!", num);
+
+    char *winning = "\nWith a mighty swing of your sword, you defeat the troll!";
+    char *you_win = "[+] You win!!\n";
+    char *losing= "\nThe troll swings his club and knocks you into next Tuesday!";
+
+
+    if (num != 9000)  {
+        printf("%s", losing);
+        printf("\n[!] Oh dear, you died! Better luck next time friend.");
+        exit(31337);
+    }
+    else {
+        printf("%s", winning);
+        printf("%s", you_win);
+        decode(flag);
+        return 0;
+    }
+    return 1;
+}