Initial commit

2023-10-09 20:49:57 +02:00
commit b7072a0b49
6 changed files with 389 additions and 0 deletions
--- a/client.c
+++ b/client.c
@@ -0,0 +1,103 @@
+#include <netdb.h>
+#include <openssl/err.h>
+#include <openssl/ssl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <zlib.h>
+
+#define BUF_LEN 1024
+
+void open_connection(const char *hostname, const char *port, const char *msg) {
+    int sfd, s;
+    struct addrinfo hints;
+    struct addrinfo *result, *rp;
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_socktype = SOCK_STREAM;
+    hints.ai_flags = 0;
+    hints.ai_protocol = 0;
+
+    s = getaddrinfo(hostname, port, &hints, &result);
+    if (s != 0) {
+        fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(s));
+        exit(EXIT_FAILURE);
+    }
+
+    for (rp = result; rp != NULL; rp = rp->ai_next) {
+        sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
+        if (sfd == -1) {
+            continue;
+        }
+
+        if (connect(sfd, rp->ai_addr, rp->ai_addrlen) != -1) {
+            break; // Success
+        }
+
+        close(sfd);
+    }
+    freeaddrinfo(result);
+
+    if (rp == NULL) {
+        fprintf(stderr, "Could not connect\n");
+        exit(EXIT_FAILURE);
+    }
+
+    SSL_library_init();
+    OpenSSL_add_all_algorithms();
+    SSL_CTX *ctx = SSL_CTX_new(TLS_method());
+    SSL_CTX_set_security_level(ctx, 1);
+    SSL_CTX_clear_options(ctx, SSL_OP_NO_COMPRESSION);
+    SSL *ssl = SSL_new(ctx);
+    SSL_set_fd(ssl, sfd);
+
+    SSL_connect(ssl);
+
+    STACK_OF(SSL_COMP) *st = SSL_COMP_get_compression_methods();
+    int has_compression = sk_SSL_COMP_num(st);
+    if (st == NULL) {
+        fprintf(stderr, "Cannot list compression methods\n");
+    } else if (sk_SSL_COMP_num(st) == 0) {
+        fprintf(stderr, "No compression methods enabled\n");
+    }
+
+    char buf[BUF_LEN] = {0};
+    strcat(buf, "GET /");
+    strncat(buf, msg, BUF_LEN / 2);
+    strcat(buf, " HTTP/1.1\r\nHost: iut.local\r\n");
+    strcat(buf, "Connection: close\r\n");
+    strcat(buf, "Cookie: flag=bAr5\r\n");
+    strcat(buf, "\r\n");
+    SSL_write(ssl, buf, strlen(buf));
+
+    if (has_compression) {
+        uLong ucompSize = strlen(buf);
+        // Use a compression level of 9
+        uLong compSize = compressBound(ucompSize);
+        char *comp = malloc(compSize);
+        compress(comp, &compSize, buf, ucompSize);
+        free(comp);
+        printf("Sent %lu data bytes\n", compSize);
+    } else {
+        printf("Sent %lu data bytes\n", strlen(buf));
+    }
+
+    ssize_t nb_read = read(sfd, buf, BUF_LEN - 1);
+    buf[nb_read] = '\0';
+    printf("%s\n", buf);
+
+    SSL_free(ssl);
+    SSL_CTX_free(ctx);
+}
+
+int main(int argc, char **argv) {
+    if (argc != 4) {
+        fprintf(stderr, "Usage: %s <hostname> <port> <message>\n", argv[0]);
+        return 1;
+    }
+    open_connection(argv[1], argv[2], argv[3]);
+    return 0;
+}