initial commit

.gitignore

@@ -0,0 +1,50 @@
+# Build directories
+build/
+builds/
+out/
+cmake-build-*/         # CLion default
+
+# CMake generated files
+CMakeCache.txt
+CMakeFiles/
+CMakeScripts/
+cmake_install.cmake
+install_manifest.txt
+compile_commands.json
+CTestTestfile.cmake
+_deps/
+
+# Compiled binaries and libraries
+*.exe
+*.out
+*.app
+*.dll
+*.so
+*.so.*
+*.dylib
+*.a
+*.lib
+
+# Debug / profiling artifacts
+*.dSYM/
+*.su
+*.idb
+*.pdb
+*.gch
+*.pch
+
+# Sanitizer / coverage output
+*.gcno
+*.gcda
+*.gcov
+default.profraw
+
+# IDE and editor files
+.vscode/
+.cache/
+.idea/
+*.swp
+*.swo
+*~
+.DS_Store
+Thumbs.db

CMakeLists.txt

@@ -0,0 +1,57 @@
+cmake_minimum_required(VERSION 3.15)
+project(Webserver)
+
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED ON)
+
+
+# Generate compile_commands.json (for clangd, IDEs, etc.)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+# Find OpenSSL (includes both libssl and libcrypto)
+find_package(OpenSSL REQUIRED)
+
+# Source files
+set(SOURCES
+    src/main.c
+)
+
+add_executable(${PROJECT_NAME} ${SOURCES})
+
+# Include OpenSSL headers
+target_include_directories(${PROJECT_NAME} PRIVATE
+    ${OPENSSL_INCLUDE_DIR}
+)
+
+# Link against OpenSSL libraries
+# OpenSSL::SSL    → libssl
+# OpenSSL::Crypto → libcrypto
+target_link_libraries(${PROJECT_NAME} PRIVATE
+    OpenSSL::SSL
+    OpenSSL::Crypto
+)
+
+# Compiler warnings + debug flags (GCC/Clang)
+target_compile_options(${PROJECT_NAME} PRIVATE
+    $<$<C_COMPILER_ID:GNU,Clang>:
+        -Wall
+        -Wextra
+        -Wpedantic
+        -Wshadow
+        -Wformat=2
+        -Wconversion
+        -Wsign-conversion
+        -Wnull-dereference
+        -Wdouble-promotion
+        -Wstrict-prototypes
+        -Wmissing-prototypes
+    >
+    $<$<C_COMPILER_ID:GNU>:
+        -fanalyzer          # GCC static analyzer
+    >
+)
+
+# Optional: print found versions for debugging
+message(STATUS "OpenSSL version: ${OPENSSL_VERSION}")
+message(STATUS "OpenSSL include dir: ${OPENSSL_INCLUDE_DIR}")
+message(STATUS "OpenSSL libraries: ${OPENSSL_LIBRARIES}")

assets/cert.pem

@@ -0,0 +1,22 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

assets/key.pem

@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----

src/main.c

@@ -0,0 +1,134 @@
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <openssl/prov_ssl.h>
+#include <openssl/ssl.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#define PORT 8080
+#define BUFFER_SIZE 1024
+
+int main(void) {
+  // http server
+  char buffer[BUFFER_SIZE];
+  char resp[] = "HTTP/1.0 200 OK\r\n"
+  "Server: webserver-c\r\n"
+  "Content-type: text/html\r\n\r\n"
+  "<html>hello, world</html>\r\n";
+
+  // create socket
+  int sockfd = socket(AF_INET, SOCK_STREAM, 0);
+  if (sockfd == -1){
+    perror("webserver (socket)");
+    return 1;
+  }
+  printf("socket created succesfully\n");
+
+  // bind to port and address
+  struct sockaddr_in host_addr;
+  socklen_t host_addr_len = sizeof(host_addr);
+  host_addr.sin_family = AF_INET;
+  host_addr.sin_port = htons(PORT);
+  host_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+  if(bind(sockfd, (struct sockaddr*)&host_addr, host_addr_len) != 0){
+    perror("webserver (bind)");
+    return 1;
+  }
+  printf("socket succesfully bound to address\n");
+
+  // TLS/SSL BLOCK
+
+  // create SSL_CTX config object
+  SSL_CTX* ctx = SSL_CTX_new(TLS_server_method());
+  if (ctx == NULL) {
+    perror("webserver (SSL_CTX)");
+    return 1;
+  }
+
+  // restrict allowed TLS version so 1.2 or above
+  if (!SSL_CTX_set_min_proto_version(ctx, TLS1_2_VERSION)) {
+    SSL_CTX_free(ctx);
+    perror("webserver (TLS_VERSION)") ;
+  }
+
+  // configure option flags
+  uint16_t opts = SSL_OP_IGNORE_UNEXPECTED_EOF; // tolerate clients hanging without a TLS "shoutdown"
+  opts |= SSL_OP_IGNORE_UNEXPECTED_EOF;         // block clients from frequent renegotiation
+  opts |= SSL_OP_SERVER_PREFERENCE;
+  SSL_CTX_set_options(ctx, opts);
+
+  // load certificate
+  if (SSL_CTX_use_certificate_chain_file(ctx, "../assets/cert.pem") <= 0) {
+    SSL_CTX_free(ctx);
+    perror("webserver (SSL_CERT)");
+    return 1;
+  }
+
+  // load private key
+  if (SSL_CTX_use_PrivateKey_file(ctx, "../assets/key.pem", SSL_FILETYPE_PEM) <= 0) {
+    SSL_CTX_free(ctx);
+    perror("webserver (SSL_KEY)");
+    return 1;
+  }
+
+  // TODO enable session caching
+ 
+  // no need to verify client by cert
+  SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
+
+  
+
+  // listen on socket
+  if(listen(sockfd, SOMAXCONN) != 0){
+    perror("webserver (listen)");
+    return 1;
+  }
+  printf("socket listening on port %d\n", PORT);
+
+  // create client address
+  struct sockaddr_in client_addr;
+  int client_addr_len = sizeof(host_addr);
+
+  // accept connections
+  while (1) {
+    int newsockfd = accept(sockfd, (struct sockaddr*) &host_addr, (socklen_t *) &host_addr_len);
+    if (newsockfd < 0){
+      perror("webserver (accept)");
+      return 1;
+    }
+    printf("connection accepted\n");
+
+    // get client addr
+    int sockn = getsockname(newsockfd, (struct sockaddr*) &client_addr, (socklen_t *) &client_addr_len);
+
+    if (sockn < 0){
+      perror("webserver (getsockname)");
+      return 1;
+    }
+    
+    // read from socket
+    ssize_t valread = read(newsockfd, buffer, BUFFER_SIZE);
+    if (valread < 0){
+      perror("webserver (read)");
+    }
+
+    // read the request
+    char method[BUFFER_SIZE], uri[BUFFER_SIZE], version[BUFFER_SIZE];
+    sscanf(buffer, "%s %s %s", method, uri, version);
+    
+    printf("[%s:%u] %s %s %s\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port), method, version, uri);
+
+    // write to the socket
+    ssize_t valwrite = write(newsockfd, resp, strlen(resp));
+    if (valwrite < 0){
+      perror("webserver (write)");
+    }
+
+    close(newsockfd);
+  }
+
+  return 0;
+}