commit a03f90a4ba6a5e3b3daf7ee66a9c7573a30bc4c0 Author: Trance-0 Date: Wed Feb 11 17:06:45 2026 -0600 init diff --git a/.env b/.env new file mode 100644 index 0000000..24a0971 --- /dev/null +++ b/.env @@ -0,0 +1,6 @@ +NET_SUBNET=172.30.0.0/24 +SERVER_IP=172.30.0.10 +CLIENT_IP=172.30.0.11 +SERVER_PORT=3030 +INITIAL_VECTOR=807DEDFDE74B0C59 +SECRET_KEY=EA514659DC556DEECFFA5FD061363642 \ No newline at end of file diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..ddd9f5a --- /dev/null +++ b/.gitignore @@ -0,0 +1,9 @@ +# latex garbages +*.aux +*.fdb_latexmk +*.fls +*.log +*.synctex.gz + +# vscode garbage +.vscode \ No newline at end of file diff --git a/CSE433S_HW1_net_stream_cipher.docx.pdf b/CSE433S_HW1_net_stream_cipher.docx.pdf new file mode 100644 index 0000000..572bb39 Binary files /dev/null and b/CSE433S_HW1_net_stream_cipher.docx.pdf differ diff --git a/bin/client b/bin/client new file mode 100755 index 0000000..ff1e730 Binary files /dev/null and b/bin/client differ diff --git a/bin/server b/bin/server new file mode 100755 index 0000000..9f3957b Binary files /dev/null and b/bin/server differ diff --git a/client-log.sh b/client-log.sh new file mode 100644 index 0000000..d3c2268 --- /dev/null +++ b/client-log.sh @@ -0,0 +1 @@ +docker logs hw1-client \ No newline at end of file diff --git a/client-term.sh b/client-term.sh new file mode 100644 index 0000000..c967000 --- /dev/null +++ b/client-term.sh @@ -0,0 +1 @@ +docker exec -it hw1-client sh diff --git a/client.cpp b/client.cpp new file mode 100644 index 0000000..58083cf --- /dev/null +++ b/client.cpp @@ -0,0 +1,146 @@ +#include +#include +#include +#include + +// open ssl +#include +#include +#include + +#include // error handling +#include // for close() + +// load environment variables from .env file +#include +#include + +void load_env(const std::string& path) { + std::ifstream f(path); + std::string line; + while (std::getline(f, line)) { + if (line.empty() || line[0] == '#') continue; + auto pos = line.find('='); + if (pos == std::string::npos) continue; + + std::string key = line.substr(0, pos); + std::string val = line.substr(pos + 1); + + #ifdef _WIN32 + _putenv_s(key.c_str(), val.c_str()); + #else + setenv(key.c_str(), val.c_str(), 1); + #endif + } +} + +// steam cipher encryption function +int stream_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key, unsigned char *iv, unsigned char *ciphertext) { + /* Declare cipher context */ + EVP_CIPHER_CTX *ctx; + + int len, ciphertext_len; + + /* Create and initialise the context */ + ctx = EVP_CIPHER_CTX_new(); + + /* Initialise the encryption operation. */ + // choice for aes_256 ref: https://stackoverflow.com/questions/1220751/how-to-choose-an-aes-encryption-mode-cbc-ecb-ctr-ocb-cfb + EVP_EncryptInit_ex(ctx, EVP_aes_256_ctr(), NULL, key, iv); + + /* Provide the message to be encrypted, and obtain the encrypted output. EVP_EncryptUpdate can be called multiple times if necessary */ + EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len); + + /* Finalize the encryption. Further cipher text bytes may be written at this stage. */ + EVP_EncryptFinal_ex(ctx, ciphertext + len, &ciphertext_len); + + /* Clean up */ + EVP_CIPHER_CTX_free(ctx); + + return ciphertext_len; +} + +int main(void){ + load_env(".env"); + // Declare variables + const char *server_ip = std::getenv("SERVER_IP"); + const int server_port = std::atoi(std::getenv("SERVER_PORT")); + printf("Connecting to server %s:%d\n", server_ip, server_port); + + char client_message[1024]; + char server_message[1024]; + const char * custom_message="Zheyuan Wu: "; + + // encryption parameters + const char *inital_vector = std::getenv("INITIAL_VECTOR"); + const char *secret_key = std::getenv("SECRET_KEY"); + + // Create socket: + int client_socket = socket(AF_INET, SOCK_STREAM, 0); + if (client_socket == -1) { + perror("Failed to create socket"); + return 1; + }else{ + printf("Socket created successfully\n"); + } + + // Send connection request to server, be sure to set por tand IP the same as server-side + struct sockaddr_in server_addr; + server_addr.sin_family = AF_INET; + server_addr.sin_port = htons(server_port); + inet_pton(AF_INET, server_ip, &server_addr.sin_addr); + + if (connect(client_socket, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) { + perror("Failed to connect to server"); + close(client_socket); + return 1; + }else{ + printf("Connected to server successfully\n"); + } + + // Get input from the user: + printf("Enter message sent to the server (type \\quit to exit): "); + // clean the buffer + memset(client_message, 0, sizeof(client_message)); + if (fgets(client_message, sizeof(client_message), stdin) == NULL) { + // EOF or error reading from stdin, exit the loop + perror("Error reading from stdin"); + return 1; + } + + while (strcmp(client_message, "\\quit\n") != 0) { + + // Send the message to server: + // add my name in the front + char buffer[2048]; + std::snprintf(buffer, sizeof(buffer), "%s%s", custom_message, client_message); + + // encrypt message + char ciphertext[2048]; + int ciphertext_len = stream_encrypt((unsigned char*)buffer, sizeof(buffer), (unsigned char*)secret_key, (unsigned char*)inital_vector, (unsigned char*)ciphertext); + + send(client_socket, ciphertext, ciphertext_len, 0); + + // Receive the server's response: + recv(client_socket, server_message, sizeof(server_message), 0); + + printf("Server's response: %s\n", server_message); + + printf("Enter message sent to the server (type \\quit to exit): "); + + // clean the buffer + memset(client_message, 0, sizeof(client_message)); + memset(server_message, 0, sizeof(server_message)); + + if (fgets(client_message, sizeof(client_message), stdin) == NULL) { + // EOF or error reading from stdin, exit the loop + perror("Error reading from stdin"); + break; + } + } + + // Close the socket + close(client_socket); + + return 0; +} \ No newline at end of file diff --git a/compile.sh b/compile.sh new file mode 100755 index 0000000..3ced259 --- /dev/null +++ b/compile.sh @@ -0,0 +1,25 @@ +#!/usr/bin/env bash +set -euo pipefail + +mkdir -p bin + +# add libssl-dev if needed + +# apt-get update && apt-get install -y --no-install-recommends libssl-dev + +# Adjust flags as you like +CXXFLAGS="-std=c++17 -O2 -Wall -Wextra -pedantic" +OPENSSL_LIBS="-lssl -lcrypto" + +g++ ${CXXFLAGS} server.cpp -o bin/server ${OPENSSL_LIBS} +g++ ${CXXFLAGS} client.cpp -o bin/client ${OPENSSL_LIBS} + +echo "Built:" +file bin/server bin/client || true + +chmod a+x bin/server bin/client + +docker compose up -d server +docker compose run --rm -it client + +echo "Done." \ No newline at end of file diff --git a/docker-compose.yml b/docker-compose.yml new file mode 100644 index 0000000..a6cc8eb --- /dev/null +++ b/docker-compose.yml @@ -0,0 +1,38 @@ +services: + server: + image: debian:bookworm-slim + container_name: hw1-server + working_dir: /app + env_file: + - .env + networks: + net-hw1: + ipv4_address: ${SERVER_IP} + volumes: + - ./bin/server:/usr/local/bin/server:ro + entrypoint: ["bash", "-lc", "apt-get update && apt-get install -y --no-install-recommends libstdc++6 iproute2 libssl-dev; exec stdbuf -oL -eL /usr/local/bin/server"] + + client: + image: debian:bookworm-slim + container_name: hw1-client + working_dir: /app + env_file: + - .env + networks: + net-hw1: + ipv4_address: ${CLIENT_IP} + depends_on: + - server + stdin_open: true + tty: true + volumes: + - ./bin/client:/usr/local/bin/client:ro + entrypoint: ["bash", "-lc", "apt-get update && apt-get install -y --no-install-recommends libstdc++6 iproute2 libssl-dev; exec stdbuf -oL -eL /usr/local/bin/client"] + +networks: + net-hw1: + name: net-hw1 + driver: bridge + ipam: + config: + - subnet: ${NET_SUBNET} diff --git a/latex/H1_CSE4303_ZheyuanWu.out b/latex/H1_CSE4303_ZheyuanWu.out new file mode 100644 index 0000000..e69de29 diff --git a/latex/H1_CSE4303_ZheyuanWu.pdf b/latex/H1_CSE4303_ZheyuanWu.pdf new file mode 100644 index 0000000..b68b3e9 Binary files /dev/null and b/latex/H1_CSE4303_ZheyuanWu.pdf differ diff --git a/latex/H1_CSE4303_ZheyuanWu.tex b/latex/H1_CSE4303_ZheyuanWu.tex new file mode 100644 index 0000000..79c201a --- /dev/null +++ b/latex/H1_CSE4303_ZheyuanWu.tex @@ -0,0 +1,144 @@ +\documentclass[11pt]{article} +\usepackage{amsmath, amsfonts, amsthm} +\usepackage{amssymb} +\usepackage{fancyhdr,parskip} +\usepackage{fullpage} +\usepackage{mathrsfs} +\usepackage{mathtools} + +\usepackage{float} + +% code listing +\usepackage{listings} +\usepackage{xcolor} +\lstset{% + language=c++, + breaklines=true, + commentstyle=\color{green}, % comment style + escapeinside={\%*}{*)}, % if you want to add LaTeX within your code + keywordstyle=\color{blue}, % keyword style + stringstyle=\color{purple}, % string literal style +} + +%% +%% Stuff above here is packages that will be used to compile your document. +%% If you've used unusual LaTeX features, you may have to install extra packages by adding them to this list. +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +\setlength{\headheight}{15.2pt} +\setlength{\headsep}{20pt} +\pagestyle{fancyplain} + +%% +%% Stuff above here is layout and formatting. If you've never used LaTeX before, you probably don't need to change any of it. +%% Later, you can learn how it all works and adjust it to your liking, or write your own formatting code. +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +%%%%%%%%%%%%%%%%%%%%%% +% These commands create theorem-like environments. +\newtheorem{theorem}{Theorem} +\newtheorem{lemma}[theorem]{Lemma} +\newtheorem{corollary}[theorem]{Corollary} +\newtheorem{prop}[theorem]{Proposition} +\newtheorem{defn}[theorem]{Definition} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% This section contains some useful macros that will save you time typing. +%% + +% Using \displaystyle (or \ds) in a block of math has a number of effects, but most notably, it makes your fractions come out bigger. +\newcommand{\ds}{\displaystyle} + +% These lines are for displaying integrals; typing \dx will make the dx at the end of the integral look better. +\newcommand{\is}{\hspace{2pt}} +\newcommand{\dx}{\is dx} + +% These commands produce the fancy Z (for the integers) and other letters conveniently. +\newcommand{\Z}{\mathbb{Z}} +\newcommand{\Q}{\mathbb{Q}} +\newcommand{\R}{\mathbb{R}} +\newcommand{\C}{\mathbb{C}} +\newcommand{\F}{\mathbb{F}} +\newcommand{\T}{\mathcal{T}} +\newcommand{\B}{\mathcal{B}} + +% for fancy empty set char +\renewcommand{\emptyset}{\varnothing} + +% customized commands for future assignements +\newcommand{\imply}{\Rightarrow} +\def\P{\mathscr{P}} +\def\L{\mathscr{L}} +\def\M{\mathscr{M}} +\DeclarePairedDelimiterX{\inp}[2]{\langle}{\rangle}{#1, #2} + +% url embedding +\usepackage{hyperref} + +\hypersetup{colorlinks=true,linkcolor=blue,urlcolor=blue} + + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% This is the header. It will appear on every page, and it's a good place to put your name, the assignment title, and stuff like that. +%% I usually leave the center header blank to avoid clutter. +%% + +\fancyhead[L]{\textbf{CSE4303 Homework 1}} +\fancyhead[C]{509191} +\fancyhead[R]{Zheyuan Wu} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +\begin{document} + + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% Actual math starts here! + + +% Use an enumerated list to write up problems. First we begin a list. + +\begin{enumerate} +\item[1.] Description of experimental setup + +We use the same docker image and settings with environment files as last time. + +For encryption method, I checked some wikis on the internet and found aes seems to be the best practically safe algorithm I can found. + +For the detailed method and distinctions for different variations for aes, I checked the post on \href{stackoverflow.com/questions/1220751/how-to-choose-an-aes-encryption-mode-cbc-ecb-ctr-ocb-cfb}{stackoverflow} for steam cipher, seems that \texttt{NVP\_aes\_256\_ctr()} is the optimal choice for us. + +\newpage +\item[2.] Server code + +\begin{enumerate} + \item Screenshot or well-formatted copy of code + \item Quick overview of what the code does in your own words. +\end{enumerate} +\newpage + +\item[3.] Client code + +\begin{enumerate} + + \item Screenshot or well-formatted copy of code + \item Quick overview of what the code does in your own words. + +\end{enumerate} +\newpage + + +\item[4.] Extra credits +\newpage + +\end{enumerate} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% Actual math ends here. Don't put any content below the \end{document} line. +%% + +\end{document} diff --git a/message.txt b/message.txt new file mode 100644 index 0000000..6f06964 --- /dev/null +++ b/message.txt @@ -0,0 +1 @@ +My password is EA514659DC556DEECFFA5FD061363642 \ No newline at end of file diff --git a/server-log.sh b/server-log.sh new file mode 100644 index 0000000..0cd26a5 --- /dev/null +++ b/server-log.sh @@ -0,0 +1 @@ +docker logs hw1-server --tail=50 \ No newline at end of file diff --git a/server.cpp b/server.cpp new file mode 100644 index 0000000..02f3452 --- /dev/null +++ b/server.cpp @@ -0,0 +1,162 @@ +#include +#include +#include +#include + +// open ssl +#include +#include +#include + +#include // for perror() +#include // for close() + +// load environment variables from .env file +#include +#include + +void load_env(const std::string& path) { + std::ifstream f(path); + std::string line; + while (std::getline(f, line)) { + if (line.empty() || line[0] == '#') continue; + auto pos = line.find('='); + if (pos == std::string::npos) continue; + + std::string key = line.substr(0, pos); + std::string val = line.substr(pos + 1); + + #ifdef _WIN32 + _putenv_s(key.c_str(), val.c_str()); + #else + setenv(key.c_str(), val.c_str(), 1); + #endif + } +} + +// Define the decryption function +int stream_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key, unsigned char *iv, unsigned char *plaintext) { + /* Declare cipher context */ + EVP_CIPHER_CTX *ctx; + + int len, plaintext_len; + + /* Create and initialise the context */ + ctx = EVP_CIPHER_CTX_new(); + + /* Initialise the decryption operation. */ + EVP_DecryptInit_ex(ctx, EVP_aes_256_ctr(), NULL, key, iv); + + /* Provide the message to be decrypted, and obtain the plaintext output. EVP_DecryptUpdate can be called multiple times if necessary */ + EVP_DecryptUpdate(ctx, plaintext, &len, ciphertext, ciphertext_len); + + /* Finalize the decryption. Further plaintext bytes may be written at this stage. */ + EVP_DecryptFinal_ex(ctx, plaintext + len, &plaintext_len); + + /* Clean up */ + EVP_CIPHER_CTX_free(ctx); + + return plaintext_len; +} + +int main(void){ + printf("Server starting...\n"); + load_env(".env"); + + // Declare variables + const char *server_ip = std::getenv("SERVER_IP"); + const int server_port = std::atoi(std::getenv("SERVER_PORT")); + char client_message[2048]; + char server_message[2048]; + const char * custom_message="Server: Hello from server, "; + + // decryption parameters + const char *inital_vector = std::getenv("INITIAL_VECTOR"); + const char *secret_key = std::getenv("SECRET_KEY"); + + // debug + printf("Server starting at IP: %s, Port: %d\n", server_ip, server_port); + + // Create socket + const int server_socket = socket(AF_INET, SOCK_STREAM, 0); + if (server_socket == -1) { + perror("Failed to create socket"); + return 1; + } + + // Bind to the set port and IP + struct sockaddr_in server_addr; + server_addr.sin_family = AF_INET; + server_addr.sin_port = htons(server_port); + inet_pton(AF_INET, server_ip, &server_addr.sin_addr); + + if (bind(server_socket, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) { + perror("Failed to bind socket"); + close(server_socket); + return 1; + } + printf("Done with binding with IP: %s, Port: %d\n", server_ip, server_port); + + // Listen for clients: + const char *client_ip = std::getenv("CLIENT_IP"); + if (listen(server_socket, 1) == -1) { + perror("Failed to listen on socket"); + close(server_socket); + return 1; + } + printf("Listening for incoming connections...\n"); + + // Accept an incoming connection + struct sockaddr_in client_addr; + socklen_t client_addr_len = sizeof(client_addr); + int client_socket = accept(server_socket, (struct sockaddr*)&client_addr, &client_addr_len); + if (client_socket == -1) { + perror("Failed to accept connection"); + close(server_socket); + return 1; + } + printf("Client connected at IP: %s \n", client_ip); + + // clean exising buffer + memset(client_message, 0, sizeof(client_message)); + + // Receive client's message + while (strcmp(client_message, "\\exit\n") != 0) { + + // clean exising buffer + memset(client_message, 0, sizeof(client_message)); + + recv(client_socket, client_message, sizeof(client_message), 0); + + // decrypt client message + char plaintext[2048]; + int plaintext_len = stream_decrypt((unsigned char*)client_message, strlen(client_message), (unsigned char*)secret_key, (unsigned char*)inital_vector, (unsigned char*)plaintext); + + printf("Msg from client: %.*s", plaintext_len, plaintext); + + // assign client message to plaintext + memcpy(client_message, plaintext, plaintext_len); + + // Respond to client + // prepare server message + memset(server_message, 0, sizeof(server_message)); + ; + + // add my name in the back as response. + std::snprintf(server_message, sizeof(server_message), "%s%s", custom_message, strtok(client_message, ":")); + + if (send(client_socket, server_message, sizeof(server_message), 0) == -1) { + perror("Failed to send message"); + close(client_socket); + close(server_socket); + return 1; + } + printf("Response sent to client: %s\n", server_message); + + } + // Close the socket + close(client_socket); + close(server_socket); + + return 0; +} \ No newline at end of file