From bee5b228b09b2b073409cd408b65122717992581 Mon Sep 17 00:00:00 2001
From: Yeol <136407746+13m0n4de@users.noreply.github.com>
Date: Fri, 18 Oct 2024 10:26:25 +0800
Subject: [PATCH] =?UTF-8?q?feat(pwn/srand):=20=E6=B7=BB=E5=8A=A0=E9=95=9C?=
 =?UTF-8?q?=E5=83=8F=E6=9E=84=E5=BB=BA=E6=96=87=E4=BB=B6?=
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---
 challenges/pwn/srand/build/Dockerfile  | 48 ++++++++++++++++++++++++++
 challenges/pwn/srand/build/init.sh     |  7 ++++
 challenges/pwn/srand/build/xinetd.conf | 17 +++++++++
 3 files changed, 72 insertions(+)
 create mode 100644 challenges/pwn/srand/build/Dockerfile
 create mode 100644 challenges/pwn/srand/build/init.sh
 create mode 100644 challenges/pwn/srand/build/xinetd.conf

diff --git a/challenges/pwn/srand/build/Dockerfile b/challenges/pwn/srand/build/Dockerfile
new file mode 100644
index 0000000..ca76040
--- /dev/null
+++ b/challenges/pwn/srand/build/Dockerfile
@@ -0,0 +1,48 @@
+FROM ubuntu:22.04 AS builder
+
+RUN apt-get update && apt-get install -y gcc make
+
+WORKDIR /build
+
+COPY src/* ./
+
+RUN make
+
+FROM ghcr.io/svuctf/base-v2/xinetd:latest
+
+# Copy initialization script and xinetd configuration
+COPY --chmod=500 init.sh /init.sh
+COPY xinetd.conf /etc/xinetd.conf
+
+# Set up the CTF environment
+RUN chmod -R 750 /home/ctf && \
+    mkdir -p /home/ctf/lib64 && \
+    mkdir -p /home/ctf/dev && \
+    mkdir -p /home/ctf/bin && \
+    mkdir -p /home/ctf/lib/x86_64-linux-gnu && \
+    mkdir -p /home/ctf/lib32
+
+# Copy necessary libraries from builder stage
+COPY --from=builder /lib/x86_64-linux-gnu/libc.so.6 /home/ctf/lib/x86_64-linux-gnu/
+COPY --from=builder /lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 /home/ctf/lib64/
+
+# Copy the challenge binary
+COPY --from=builder --chmod=500 /build/game /home/ctf/game
+
+# Set up device nodes
+RUN mknod /home/ctf/dev/null c 1 3 && \
+    mknod /home/ctf/dev/zero c 1 5 && \
+    mknod /home/ctf/dev/random c 1 8 && \
+    mknod /home/ctf/dev/urandom c 1 9 && \
+    chmod 666 /home/ctf/dev/*
+
+# Copy necessary binaries abd binaries
+RUN cp /lib/ld-musl-x86_64.so.1 /home/ctf/lib/ && \
+    cp /bin/sh /home/ctf/bin && \
+    cp /bin/ls /home/ctf/bin && \
+    cp /bin/cat /home/ctf/bin && \
+    cp /bin/base64 /home/ctf/bin 
+
+RUN chown -R ctf:ctf /home/ctf 
+
+CMD ["xinetd", "-dontfork"]
diff --git a/challenges/pwn/srand/build/init.sh b/challenges/pwn/srand/build/init.sh
new file mode 100644
index 0000000..1a0acaf
--- /dev/null
+++ b/challenges/pwn/srand/build/init.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+echo $GZCTF_FLAG > /home/ctf/flag
+chown -R ctf:ctf /home/ctf/flag
+unset GZCTF_FLAG
+
+/usr/sbin/chroot /home/ctf/ /game
diff --git a/challenges/pwn/srand/build/xinetd.conf b/challenges/pwn/srand/build/xinetd.conf
new file mode 100644
index 0000000..d54df8f
--- /dev/null
+++ b/challenges/pwn/srand/build/xinetd.conf
@@ -0,0 +1,17 @@
+service ctf
+{
+    disable     = no
+    id          = xinetd
+    socket_type = stream
+    protocol    = tcp
+    wait        = no
+    user        = root
+    type        = UNLISTED
+    port        = 70
+    bind        = 0.0.0.0
+    server      = /init.sh
+    # safety options
+    per_source  = 10 # the maximum instances of this service per source IP address
+    rlimit_cpu  = 20 # the maximum number of CPU seconds that the service may use
+    rlimit_as   = 100M # the Address Space resource limit for the service
+}