init

client/main.cpp

@@ -0,0 +1,155 @@
+#include "../common/defines.h"
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <openssl/err.h>
+#include <openssl/ssl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+void error(const char *msg) {
+  perror(msg);
+  exit(EXIT_FAILURE);
+}
+
+int main(int argc, char *argv[]) {
+  if (argc < 3) {
+    fprintf(stderr, "Usage: %s <server_ip> <port>\n", argv[0]);
+    exit(EXIT_FAILURE);
+  }
+
+  // Initialize OpenSSL (for OpenSSL 1.1.0+ this is optional as it's automatic)
+  OPENSSL_init_ssl(0, NULL);
+
+  // Create a TLS 1.3 client context
+  SSL_CTX *ctx = SSL_CTX_new(TLS_client_method());
+  if (ctx == NULL) {
+    ERR_print_errors_fp(stderr);
+    error("Failed to create SSL_CTX");
+  }
+
+  // Set minimum TLS version to 1.3
+  if (SSL_CTX_set_min_proto_version(ctx, TLS1_3_VERSION) != 1) {
+    SSL_CTX_free(ctx);
+    ERR_print_errors_fp(stderr);
+    error("Error setting minimum TLS version");
+  }
+
+  // Load CA certificate for server verification
+  if (SSL_CTX_load_verify_locations(ctx, "certs/mldsa87_root_cert.pem", NULL) !=
+      1) {
+    SSL_CTX_free(ctx);
+    ERR_print_errors_fp(stderr);
+    error("Error loading CA certificate");
+  }
+
+  // Set cipher suite for TLS 1.3
+  if (SSL_CTX_set_ciphersuites(ctx, "TLS_AES_256_GCM_SHA384") != 1) {
+    SSL_CTX_free(ctx);
+    ERR_print_errors_fp(stderr);
+    error("Error setting cipher list");
+  }
+
+  // Create a TCP socket
+  int sockfd = socket(AF_INET, SOCK_STREAM, 0);
+  if (sockfd < 0)
+    error("Socket creation failed");
+
+  // Set up server address
+  struct sockaddr_in serv_addr;
+  memset(&serv_addr, 0, sizeof(serv_addr));
+  serv_addr.sin_family = AF_INET;
+  serv_addr.sin_port = htons(atoi(argv[2]));
+  if (inet_pton(AF_INET, argv[1], &serv_addr.sin_addr) <= 0)
+    error("Invalid address/address not supported");
+
+  // Connect to server
+  if (connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0)
+    error("Connection failed");
+
+  printf("Connected to %s:%s\n", argv[1], argv[2]);
+
+  // Create an SSL object
+  SSL *ssl = SSL_new(ctx);
+  if (ssl == NULL) {
+    close(sockfd);
+    SSL_CTX_free(ctx);
+    ERR_print_errors_fp(stderr);
+    error("Failed to create SSL object");
+  }
+
+  // Associate the socket with SSL
+  if (SSL_set_fd(ssl, sockfd) != 1) {
+    SSL_free(ssl);
+    close(sockfd);
+    SSL_CTX_free(ctx);
+    ERR_print_errors_fp(stderr);
+    error("Failed to set SSL file descriptor");
+  }
+
+  // Connect using TLS
+  int ret = SSL_connect(ssl);
+  if (ret != 1) {
+    fprintf(stderr, "TLS handshake failed: %d\n", SSL_get_error(ssl, ret));
+    ERR_print_errors_fp(stderr);
+    SSL_free(ssl);
+    close(sockfd);
+    SSL_CTX_free(ctx);
+    exit(EXIT_FAILURE);
+  }
+
+  printf("TLS 1.3 handshake successful using %s\n", SSL_get_cipher(ssl));
+
+  // Fork to handle sending and receiving
+  pid_t pid = fork();
+  if (pid < 0)
+    error("Fork failed");
+
+  if (pid == 0) { // Child process: receive from server
+    char buffer[BUFFER_SIZE];
+    int bytes_read;
+
+    while (1) {
+      bytes_read = SSL_read(ssl, buffer, BUFFER_SIZE);
+
+      if (bytes_read > 0) {
+        fwrite(buffer, 1, bytes_read, stdout);
+        fflush(stdout);
+        memset(buffer, 0, BUFFER_SIZE);
+      } else {
+        int err = SSL_get_error(ssl, bytes_read);
+        if (err == SSL_ERROR_WANT_READ)
+          continue;
+        else
+          break;
+      }
+    }
+
+    kill(getppid(), SIGTERM); // Signal parent to terminate
+    exit(0);
+  } else { // Parent process: send to server
+    char buffer[BUFFER_SIZE];
+    int bytes_read;
+
+    while ((bytes_read = read(STDIN_FILENO, buffer, BUFFER_SIZE)) > 0) {
+      if (SSL_write(ssl, buffer, bytes_read) < 0) {
+        fprintf(stderr, "SSL_write error: %d\n", SSL_get_error(ssl, 0));
+        break;
+      }
+    }
+
+    kill(pid, SIGTERM); // Signal child to terminate
+  }
+
+  // Clean up
+  SSL_shutdown(ssl);
+  SSL_free(ssl);
+  close(sockfd);
+  SSL_CTX_free(ctx);
+
+  return 0;
+}