Fstrings (#13)

* 32Bit Fstrings

* Move Demo to 32Bit

* First Format Strings Target Done

* Trget 1 Added

* first Challenge Added

Week7_Fstrings/ChallengeOne/builder/Dockerfile

@@ -0,0 +1,19 @@
+FROM ghcr.io/coventryuniversity/6048builder as ClientBuilder
+
+RUN apt install -y --no-install-recommends python3 python3-jinja2
+
+ADD src /opt
+
+WORKDIR /opt
+
+#We want to rebuld this each time
+#ADD "https://www.random.org/cgi-bin/randbyte?nbytes=10&format=h" skipcache
+
+RUN python3 /opt/process.py && gcc -fno-stack-protector  /opt/target.c -o /opt/target
+
+FROM ghcr.io/coventryuniversity/6048server
+COPY --from=ClientBuilder /opt/target /home/cueh/target
+
+ADD runserver.sh /opt/
+
+CMD ["/bin/bash", "/opt/runserver.sh"]

Week7_Fstrings/ChallengeOne/builder/runserver.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+echo "Starting Remote Service on port 1337"
+
+/opt/server /home/cueh/target

Week7_Fstrings/ChallengeOne/builder/src/process.py

@@ -0,0 +1,38 @@
+import logging
+import random
+import string
+
+import jinja2
+
+def create_target():
+    """
+    Create the Target C File
+
+    @param seed:  Seed for the target, between 0 and 32
+    """
+
+    env = jinja2.Environment(loader=jinja2.FileSystemLoader(searchpath="."))
+
+    template = env.get_template("target.jinja2")
+
+    username = random.choice(["Zaphod",
+                              "Ford",
+                              "Arthur",
+                              "Tricia"])
+
+    logging.debug("User is %s", username)
+    password = "".join(random.choice(string.ascii_letters) for x in range(16))
+    logging.debug("Password is %s", password)
+
+    result = template.render(username = username,
+                             password = password)
+
+    with open("target.c", "w") as fd:
+        fd.write(result)
+
+
+if __name__ == "__main__":
+
+    logging.basicConfig(level=logging.DEBUG)
+
+    create_target()

Week7_Fstrings/ChallengeOne/builder/src/target.jinja2

@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+int BUFFER = 32;
+
+
+int main(int argc, char* argv[]){
+  setvbuf(stdout, NULL, _IONBF, 0);
+  char username[16] = "{{ username }}";
+  char password[32] = "{{ password }}";
+  int attempts = 3;
+  char user[BUFFER];
+  char pass[BUFFER];
+
+  /* Main Function*/
+  while (attempts > 0){
+    //Get Data
+    printf("Enter Username >");
+    scanf("%32s", user);
+    printf("Enter Password >");
+    scanf("%32s", pass);
+
+    //Compare user
+    if(strcmp(username, user)){
+      printf("Incorrect Username ");
+      printf(user);
+      printf("\n");
+      attempts -= 1;
+    }
+    else{
+      //Compare Password
+      if(strcmp(pass, password)){
+	//A Non Zero == Fail
+	printf("Access Denied\n");
+	attempts -= 1;
+      }
+      else{
+	printf("Access Granted\n");
+	return 1;
+      }
+    }
+    printf("\n%d Attempts Remain\n", attempts);
+  }
+  return 0;
+}

Week7_Fstrings/ChallengeOne/docker-compose.yaml

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+version: "3.7"
+
+services:
+  server:
+    build:
+      context: builder
+      args:
+        CACHE: "$(date)"
+    ports:
+      - "1337:1337"
+#      - "22:22"

Week7_Fstrings/ChallengeOne/target.c

@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+int BUFFER = 32;
+
+
+int main(int argc, char* argv[]){
+  setvbuf(stdout, NULL, _IONBF, 0);
+  char username[32] = "Someone";    //0-16 Letter Username
+  char password[32] = "sECcuzDyeFmiXXbN"; // 0-16 Letter Password
+  int attempts = 3;
+  char user[BUFFER];
+  char pass[BUFFER];
+
+  /* Main Function*/
+  while (attempts > 0){
+    //Get Data
+    printf("Enter Username >");
+    scanf("%32s", user);
+    printf("Enter Password >");
+    scanf("%32s", pass);
+
+    //Compare user
+    if(strcmp(username, user)){
+      printf("Incorrect Username ");
+      printf(user);
+      printf("\n");
+      attempts -= 1;
+    }
+    else{
+      //Compare Password
+      if(strcmp(pass, password)){
+	//A Non Zero == Fail
+	printf("Access Denied\n");
+	attempts -= 1;
+      }
+      else{
+	printf("Access Granted\n");
+	return 1;
+      }
+    }
+    printf("\n%d Attempts Remain\n", attempts);
+  }
+  return 0;
+}