Added a simple rop problem

Needs to be built on a linux machine and the binary put in the
files/description so that its easier to solve. Also needs to be put on
the shell.

simple-rop/Makefile

@@ -0,0 +1,2 @@
+(all):
+	gcc -m32 -o simple-rop -fno-stack-protector -O0 simple-rop.c

simple-rop/description.md

@@ -0,0 +1,3 @@
+On the shell there is a folder `<insert location>`.
+Read flag.txt
+[Source](${simple-rop.c})

simple-rop/flag.txt

@@ -0,0 +1 @@
+easyctf{r0p_7o_v1ct0ry}

simple-rop/grader.py

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+def grade(random, key):
+    if key.find("r0p_7o_v1ct0ry") != -1:
+        return True, "Correct!"
+    return False, "Nope."

simple-rop/problem.yml

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+title: Simple Rop
+category: Binary Exploitation
+value: 75
+author: r3ndom
+autogen: false
+files:
+  - simple-rop.c

simple-rop/simple-rop.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+void print_flag();
+void what_did_you_say();
+
+int main(int argc, char* argv[])
+{
+    gid_t gid = getegid();
+    setresgid(gid, gid, gid);
+    what_did_you_say();
+    return 0;
+}
+
+void print_flag()
+{
+    system("cat flag.txt");
+}
+
+void what_did_you_say()
+{
+    char buff[64];
+    gets(buff);
+    printf("You said: %s\n", buff);
+}