mirror of
https://github.com/kasmtech/KasmVNC.git
synced 2024-11-22 16:13:13 +01:00
1036 lines
28 KiB
C
1036 lines
28 KiB
C
/*
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* WebSocket lib with support for "wss://" encryption.
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* Copyright 2010 Joel Martin
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* Licensed under LGPL version 3 (see docs/LICENSE.LGPL-3)
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*
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* You can make a cert/key with openssl using:
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* openssl req -new -x509 -days 365 -nodes -out self.pem -keyout self.pem
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* as taken from http://docs.python.org/dev/library/ssl.html#certificates
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*/
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#define _GNU_SOURCE
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#include <pthread.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <string.h>
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#include <dirent.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/stat.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <netdb.h>
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#include <fcntl.h> // daemonizing
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#include <openssl/err.h>
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#include <openssl/ssl.h>
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#include <openssl/bio.h> /* base64 encode/decode */
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#include <openssl/md5.h> /* md5 hash */
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#include <openssl/sha.h> /* sha1 hash */
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#include "websocket.h"
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/*
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* Global state
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*
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* Warning: not thread safe
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*/
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int ssl_initialized = 0;
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int pipe_error = 0;
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settings_t settings;
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void traffic(const char * token) {
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/*if ((settings.verbose) && (! settings.daemon)) {
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fprintf(stdout, "%s", token);
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fflush(stdout);
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}*/
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}
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void error(char *msg)
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{
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perror(msg);
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}
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void fatal(char *msg)
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{
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perror(msg);
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exit(1);
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}
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/* resolve host with also IP address parsing */
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int resolve_host(struct in_addr *sin_addr, const char *hostname)
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{
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if (!inet_aton(hostname, sin_addr)) {
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struct addrinfo *ai, *cur;
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struct addrinfo hints;
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memset(&hints, 0, sizeof(hints));
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hints.ai_family = AF_INET;
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if (getaddrinfo(hostname, NULL, &hints, &ai))
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return -1;
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for (cur = ai; cur; cur = cur->ai_next) {
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if (cur->ai_family == AF_INET) {
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*sin_addr = ((struct sockaddr_in *)cur->ai_addr)->sin_addr;
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freeaddrinfo(ai);
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return 0;
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}
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}
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freeaddrinfo(ai);
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return -1;
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}
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return 0;
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}
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/*
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* SSL Wrapper Code
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*/
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ssize_t ws_recv(ws_ctx_t *ctx, void *buf, size_t len) {
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if (ctx->ssl) {
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//handler_msg("SSL recv\n");
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return SSL_read(ctx->ssl, buf, len);
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} else {
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return recv(ctx->sockfd, buf, len, 0);
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}
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}
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ssize_t ws_send(ws_ctx_t *ctx, const void *buf, size_t len) {
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if (ctx->ssl) {
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//handler_msg("SSL send\n");
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return SSL_write(ctx->ssl, buf, len);
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} else {
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return send(ctx->sockfd, buf, len, 0);
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}
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}
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ws_ctx_t *alloc_ws_ctx() {
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ws_ctx_t *ctx;
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if (! (ctx = malloc(sizeof(ws_ctx_t))) )
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{ fatal("malloc()"); }
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if (! (ctx->cin_buf = malloc(BUFSIZE)) )
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{ fatal("malloc of cin_buf"); }
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if (! (ctx->cout_buf = malloc(BUFSIZE)) )
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{ fatal("malloc of cout_buf"); }
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if (! (ctx->tin_buf = malloc(BUFSIZE)) )
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{ fatal("malloc of tin_buf"); }
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if (! (ctx->tout_buf = malloc(BUFSIZE)) )
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{ fatal("malloc of tout_buf"); }
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ctx->headers = malloc(sizeof(headers_t));
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ctx->ssl = NULL;
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ctx->ssl_ctx = NULL;
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return ctx;
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}
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void free_ws_ctx(ws_ctx_t *ctx) {
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free(ctx->cin_buf);
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free(ctx->cout_buf);
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free(ctx->tin_buf);
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free(ctx->tout_buf);
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free(ctx);
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}
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ws_ctx_t *ws_socket(ws_ctx_t *ctx, int socket) {
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ctx->sockfd = socket;
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return ctx;
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}
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ws_ctx_t *ws_socket_ssl(ws_ctx_t *ctx, int socket, char * certfile, char * keyfile) {
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int ret;
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char msg[1024];
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char * use_keyfile;
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ws_socket(ctx, socket);
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if (keyfile && (keyfile[0] != '\0')) {
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// Separate key file
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use_keyfile = keyfile;
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} else {
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// Combined key and cert file
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use_keyfile = certfile;
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}
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// Initialize the library
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if (! ssl_initialized) {
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SSL_library_init();
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OpenSSL_add_all_algorithms();
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SSL_load_error_strings();
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ssl_initialized = 1;
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}
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ctx->ssl_ctx = SSL_CTX_new(TLSv1_server_method());
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if (ctx->ssl_ctx == NULL) {
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ERR_print_errors_fp(stderr);
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fatal("Failed to configure SSL context");
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}
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if (SSL_CTX_use_PrivateKey_file(ctx->ssl_ctx, use_keyfile,
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SSL_FILETYPE_PEM) <= 0) {
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sprintf(msg, "Unable to load private key file %s\n", use_keyfile);
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fatal(msg);
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}
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if (SSL_CTX_use_certificate_chain_file(ctx->ssl_ctx, certfile) <= 0) {
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sprintf(msg, "Unable to load certificate file %s\n", certfile);
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fatal(msg);
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}
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// if (SSL_CTX_set_cipher_list(ctx->ssl_ctx, "DEFAULT") != 1) {
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// sprintf(msg, "Unable to set cipher\n");
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// fatal(msg);
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// }
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// Associate socket and ssl object
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ctx->ssl = SSL_new(ctx->ssl_ctx);
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SSL_set_fd(ctx->ssl, socket);
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ret = SSL_accept(ctx->ssl);
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if (ret < 0) {
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ERR_print_errors_fp(stderr);
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return NULL;
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}
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return ctx;
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}
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void ws_socket_free(ws_ctx_t *ctx) {
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if (ctx->ssl) {
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SSL_free(ctx->ssl);
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ctx->ssl = NULL;
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}
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if (ctx->ssl_ctx) {
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SSL_CTX_free(ctx->ssl_ctx);
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ctx->ssl_ctx = NULL;
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}
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if (ctx->sockfd) {
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shutdown(ctx->sockfd, SHUT_RDWR);
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close(ctx->sockfd);
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ctx->sockfd = 0;
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}
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}
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int ws_b64_ntop(const unsigned char const * src, size_t srclen, char * dst, size_t dstlen) {
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int len = 0;
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int total_len = 0;
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BIO *buff, *b64f;
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BUF_MEM *ptr;
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b64f = BIO_new(BIO_f_base64());
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buff = BIO_new(BIO_s_mem());
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buff = BIO_push(b64f, buff);
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BIO_set_flags(buff, BIO_FLAGS_BASE64_NO_NL);
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BIO_set_close(buff, BIO_CLOSE);
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do {
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len = BIO_write(buff, src + total_len, srclen - total_len);
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if (len > 0)
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total_len += len;
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} while (len && BIO_should_retry(buff));
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BIO_flush(buff);
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BIO_get_mem_ptr(buff, &ptr);
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len = ptr->length;
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memcpy(dst, ptr->data, dstlen < len ? dstlen : len);
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dst[dstlen < len ? dstlen : len] = '\0';
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BIO_free_all(buff);
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if (dstlen < len)
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return -1;
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return len;
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}
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int ws_b64_pton(const char const * src, unsigned char * dst, size_t dstlen) {
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int len = 0;
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int total_len = 0;
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int pending = 0;
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BIO *buff, *b64f;
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b64f = BIO_new(BIO_f_base64());
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buff = BIO_new_mem_buf(src, -1);
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buff = BIO_push(b64f, buff);
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BIO_set_flags(buff, BIO_FLAGS_BASE64_NO_NL);
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BIO_set_close(buff, BIO_CLOSE);
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do {
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len = BIO_read(buff, dst + total_len, dstlen - total_len);
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if (len > 0)
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total_len += len;
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} while (len && BIO_should_retry(buff));
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dst[total_len] = '\0';
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pending = BIO_ctrl_pending(buff);
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BIO_free_all(buff);
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if (pending)
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return -1;
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return len;
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}
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/* ------------------------------------------------------- */
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int encode_hixie(u_char const *src, size_t srclength,
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char *target, size_t targsize) {
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int sz = 0, len = 0;
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target[sz++] = '\x00';
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len = ws_b64_ntop(src, srclength, target+sz, targsize-sz);
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if (len < 0) {
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return len;
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}
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sz += len;
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target[sz++] = '\xff';
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return sz;
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}
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int decode_hixie(char *src, size_t srclength,
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u_char *target, size_t targsize,
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unsigned int *opcode, unsigned int *left) {
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char *start, *end, cntstr[4];
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int len, framecount = 0, retlen = 0;
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if ((src[0] != '\x00') || (src[srclength-1] != '\xff')) {
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handler_emsg("WebSocket framing error\n");
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return -1;
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}
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*left = srclength;
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if (srclength == 2 &&
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(src[0] == '\xff') &&
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(src[1] == '\x00')) {
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// client sent orderly close frame
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*opcode = 0x8; // Close frame
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return 0;
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}
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*opcode = 0x1; // Text frame
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start = src+1; // Skip '\x00' start
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do {
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/* We may have more than one frame */
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end = (char *)memchr(start, '\xff', srclength);
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*end = '\x00';
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len = ws_b64_pton(start, target+retlen, targsize-retlen);
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if (len < 0) {
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return len;
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}
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retlen += len;
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start = end + 2; // Skip '\xff' end and '\x00' start
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framecount++;
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} while (end < (src+srclength-1));
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if (framecount > 1) {
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snprintf(cntstr, 3, "%d", framecount);
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traffic(cntstr);
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}
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*left = 0;
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return retlen;
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}
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int encode_hybi(u_char const *src, size_t srclength,
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char *target, size_t targsize, unsigned int opcode)
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{
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unsigned long long payload_offset = 2;
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int len = 0;
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if (opcode != OPCODE_TEXT && opcode != OPCODE_BINARY) {
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handler_emsg("Invalid opcode. Opcode must be 0x01 for text mode, or 0x02 for binary mode.\n");
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return -1;
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}
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target[0] = (char)((opcode & 0x0F) | 0x80);
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if ((int)srclength <= 0) {
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return 0;
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}
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if (opcode & OPCODE_TEXT) {
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len = ((srclength - 1) / 3) * 4 + 4;
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} else {
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len = srclength;
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}
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if (len <= 125) {
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target[1] = (char) len;
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payload_offset = 2;
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} else if ((len > 125) && (len < 65536)) {
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target[1] = (char) 126;
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*(u_short*)&(target[2]) = htons(len);
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payload_offset = 4;
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} else {
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handler_emsg("Sending frames larger than 65535 bytes not supported\n");
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return -1;
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//target[1] = (char) 127;
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// *(u_long*)&(target[2]) = htonl(b64_sz);
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//payload_offset = 10;
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}
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if (opcode & OPCODE_TEXT) {
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len = ws_b64_ntop(src, srclength, target+payload_offset, targsize-payload_offset);
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} else {
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memcpy(target+payload_offset, src, srclength);
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len = srclength;
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}
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if (len < 0) {
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return len;
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}
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return len + payload_offset;
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}
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int decode_hybi(unsigned char *src, size_t srclength,
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u_char *target, size_t targsize,
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unsigned int *opcode, unsigned int *left)
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{
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unsigned char *frame, *mask, *payload, save_char;
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char cntstr[4];
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int masked = 0;
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int i = 0, len, framecount = 0;
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size_t remaining = 0;
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unsigned int target_offset = 0, hdr_length = 0, payload_length = 0;
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*left = srclength;
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frame = src;
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//printf("Deocde new frame\n");
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while (1) {
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// Need at least two bytes of the header
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// Find beginning of next frame. First time hdr_length, masked and
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// payload_length are zero
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frame += hdr_length + 4*masked + payload_length;
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//printf("frame[0..3]: 0x%x 0x%x 0x%x 0x%x (tot: %d)\n",
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// (unsigned char) frame[0],
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// (unsigned char) frame[1],
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// (unsigned char) frame[2],
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// (unsigned char) frame[3], srclength);
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if (frame > src + srclength) {
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//printf("Truncated frame from client, need %d more bytes\n", frame - (src + srclength) );
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break;
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}
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remaining = (src + srclength) - frame;
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if (remaining < 2) {
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//printf("Truncated frame header from client\n");
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break;
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}
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framecount ++;
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*opcode = frame[0] & 0x0f;
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masked = (frame[1] & 0x80) >> 7;
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if (*opcode == 0x8) {
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// client sent orderly close frame
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break;
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}
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payload_length = frame[1] & 0x7f;
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if (payload_length < 126) {
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hdr_length = 2;
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//frame += 2 * sizeof(char);
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} else if (payload_length == 126) {
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payload_length = (frame[2] << 8) + frame[3];
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hdr_length = 4;
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} else {
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handler_emsg("Receiving frames larger than 65535 bytes not supported\n");
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return -1;
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}
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if ((hdr_length + 4*masked + payload_length) > remaining) {
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continue;
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}
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//printf(" payload_length: %u, raw remaining: %u\n", payload_length, remaining);
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payload = frame + hdr_length + 4*masked;
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if (*opcode != OPCODE_TEXT && *opcode != OPCODE_BINARY) {
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handler_msg("Ignoring non-data frame, opcode 0x%x\n", *opcode);
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continue;
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}
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if (payload_length == 0) {
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handler_msg("Ignoring empty frame\n");
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continue;
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}
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if ((payload_length > 0) && (!masked)) {
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handler_emsg("Received unmasked payload from client\n");
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return -1;
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}
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// Terminate with a null for base64 decode
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save_char = payload[payload_length];
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payload[payload_length] = '\0';
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// unmask the data
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mask = payload - 4;
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for (i = 0; i < payload_length; i++) {
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payload[i] ^= mask[i%4];
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}
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if (*opcode & OPCODE_TEXT) {
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// base64 decode the data
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len = ws_b64_pton((const char*)payload, target+target_offset, targsize);
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} else {
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memcpy(target+target_offset, payload, payload_length);
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len = payload_length;
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}
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// Restore the first character of the next frame
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payload[payload_length] = save_char;
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if (len < 0) {
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handler_emsg("Base64 decode error code %d", len);
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return len;
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}
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target_offset += len;
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//printf(" len %d, raw %s\n", len, frame);
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}
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if (framecount > 1) {
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snprintf(cntstr, 3, "%d", framecount);
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traffic(cntstr);
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}
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*left = remaining;
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return target_offset;
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}
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int parse_handshake(ws_ctx_t *ws_ctx, char *handshake) {
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char *start, *end;
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headers_t *headers = ws_ctx->headers;
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headers->key1[0] = '\0';
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headers->key2[0] = '\0';
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headers->key3[0] = '\0';
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if ((strlen(handshake) < 92) || (bcmp(handshake, "GET ", 4) != 0) ||
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(!strstr(handshake, "Upgrade: websocket"))) {
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return 0;
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}
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start = handshake+4;
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end = strstr(start, " HTTP/1.1");
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if (!end) { return 0; }
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strncpy(headers->path, start, end-start);
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headers->path[end-start] = '\0';
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start = strstr(handshake, "\r\nHost: ");
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if (!start) { return 0; }
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start += 8;
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end = strstr(start, "\r\n");
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strncpy(headers->host, start, end-start);
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headers->host[end-start] = '\0';
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|
|
headers->origin[0] = '\0';
|
|
start = strstr(handshake, "\r\nOrigin: ");
|
|
if (start) {
|
|
start += 10;
|
|
} else {
|
|
start = strstr(handshake, "\r\nSec-WebSocket-Origin: ");
|
|
if (!start) { return 0; }
|
|
start += 24;
|
|
}
|
|
end = strstr(start, "\r\n");
|
|
strncpy(headers->origin, start, end-start);
|
|
headers->origin[end-start] = '\0';
|
|
|
|
start = strstr(handshake, "\r\nSec-WebSocket-Version: ");
|
|
if (start) {
|
|
// HyBi/RFC 6455
|
|
start += 25;
|
|
end = strstr(start, "\r\n");
|
|
strncpy(headers->version, start, end-start);
|
|
headers->version[end-start] = '\0';
|
|
ws_ctx->hixie = 0;
|
|
ws_ctx->hybi = strtol(headers->version, NULL, 10);
|
|
|
|
start = strstr(handshake, "\r\nSec-WebSocket-Key: ");
|
|
if (!start) { return 0; }
|
|
start += 21;
|
|
end = strstr(start, "\r\n");
|
|
strncpy(headers->key1, start, end-start);
|
|
headers->key1[end-start] = '\0';
|
|
|
|
start = strstr(handshake, "\r\nConnection: ");
|
|
if (!start) { return 0; }
|
|
start += 14;
|
|
end = strstr(start, "\r\n");
|
|
strncpy(headers->connection, start, end-start);
|
|
headers->connection[end-start] = '\0';
|
|
|
|
start = strstr(handshake, "\r\nSec-WebSocket-Protocol: ");
|
|
if (!start) { return 0; }
|
|
start += 26;
|
|
end = strstr(start, "\r\n");
|
|
strncpy(headers->protocols, start, end-start);
|
|
headers->protocols[end-start] = '\0';
|
|
} else {
|
|
// Hixie 75 or 76
|
|
ws_ctx->hybi = 0;
|
|
|
|
start = strstr(handshake, "\r\n\r\n");
|
|
if (!start) { return 0; }
|
|
start += 4;
|
|
if (strlen(start) == 8) {
|
|
ws_ctx->hixie = 76;
|
|
strncpy(headers->key3, start, 8);
|
|
headers->key3[8] = '\0';
|
|
|
|
start = strstr(handshake, "\r\nSec-WebSocket-Key1: ");
|
|
if (!start) { return 0; }
|
|
start += 22;
|
|
end = strstr(start, "\r\n");
|
|
strncpy(headers->key1, start, end-start);
|
|
headers->key1[end-start] = '\0';
|
|
|
|
start = strstr(handshake, "\r\nSec-WebSocket-Key2: ");
|
|
if (!start) { return 0; }
|
|
start += 22;
|
|
end = strstr(start, "\r\n");
|
|
strncpy(headers->key2, start, end-start);
|
|
headers->key2[end-start] = '\0';
|
|
} else {
|
|
ws_ctx->hixie = 75;
|
|
}
|
|
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
int parse_hixie76_key(char * key) {
|
|
unsigned long i, spaces = 0, num = 0;
|
|
for (i=0; i < strlen(key); i++) {
|
|
if (key[i] == ' ') {
|
|
spaces += 1;
|
|
}
|
|
if ((key[i] >= 48) && (key[i] <= 57)) {
|
|
num = num * 10 + (key[i] - 48);
|
|
}
|
|
}
|
|
return num / spaces;
|
|
}
|
|
|
|
int gen_md5(headers_t *headers, char *target) {
|
|
unsigned long key1 = parse_hixie76_key(headers->key1);
|
|
unsigned long key2 = parse_hixie76_key(headers->key2);
|
|
char *key3 = headers->key3;
|
|
|
|
MD5_CTX c;
|
|
char in[HIXIE_MD5_DIGEST_LENGTH] = {
|
|
key1 >> 24, key1 >> 16, key1 >> 8, key1,
|
|
key2 >> 24, key2 >> 16, key2 >> 8, key2,
|
|
key3[0], key3[1], key3[2], key3[3],
|
|
key3[4], key3[5], key3[6], key3[7]
|
|
};
|
|
|
|
MD5_Init(&c);
|
|
MD5_Update(&c, (void *)in, sizeof in);
|
|
MD5_Final((void *)target, &c);
|
|
|
|
target[HIXIE_MD5_DIGEST_LENGTH] = '\0';
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void gen_sha1(headers_t *headers, char *target) {
|
|
SHA_CTX c;
|
|
unsigned char hash[SHA_DIGEST_LENGTH];
|
|
int r;
|
|
|
|
SHA1_Init(&c);
|
|
SHA1_Update(&c, headers->key1, strlen(headers->key1));
|
|
SHA1_Update(&c, HYBI_GUID, 36);
|
|
SHA1_Final(hash, &c);
|
|
|
|
r = ws_b64_ntop(hash, sizeof hash, target, HYBI10_ACCEPTHDRLEN);
|
|
//assert(r == HYBI10_ACCEPTHDRLEN - 1);
|
|
}
|
|
|
|
static const char *name2mime(const char *name) {
|
|
|
|
const char *end = strrchr(name, '.');
|
|
if (!end)
|
|
goto def;
|
|
end++;
|
|
|
|
#define CMP(s) if (!strncmp(end, s, sizeof(s) - 1))
|
|
|
|
CMP("htm")
|
|
return "text/html";
|
|
CMP("txt")
|
|
return "text/plain";
|
|
|
|
CMP("css")
|
|
return "text/css";
|
|
CMP("js")
|
|
return "application/javascript";
|
|
|
|
CMP("gif")
|
|
return "image/gif";
|
|
CMP("jpg")
|
|
return "image/jpeg";
|
|
CMP("jpeg")
|
|
return "image/jpeg";
|
|
CMP("png")
|
|
return "image/png";
|
|
CMP("svg")
|
|
return "image/svg+xml";
|
|
|
|
#undef CMP
|
|
|
|
def:
|
|
return "application/octet-stream";
|
|
}
|
|
|
|
static void dirlisting(ws_ctx_t *ws_ctx, const char fullpath[], const char path[]) {
|
|
char buf[4096];
|
|
unsigned i;
|
|
|
|
// Redirect?
|
|
const unsigned len = strlen(fullpath);
|
|
if (fullpath[len - 1] != '/') {
|
|
sprintf(buf, "HTTP/1.1 301 Moved Permanently\r\n"
|
|
"Server: KasmVNC/4.0\r\n"
|
|
"Location: %s/\r\n"
|
|
"Connection: close\r\n"
|
|
"Content-type: text/plain\r\n"
|
|
"\r\n", path);
|
|
ws_send(ws_ctx, buf, strlen(buf));
|
|
return;
|
|
}
|
|
|
|
const char *start = memrchr(path, '/', len - 1);
|
|
if (!start) start = path;
|
|
|
|
// Directory listing
|
|
sprintf(buf, "HTTP/1.1 200 OK\r\n"
|
|
"Server: KasmVNC/4.0\r\n"
|
|
"Connection: close\r\n"
|
|
"Content-type: text/html\r\n"
|
|
"\r\n<html><title>Directory Listing</title><body><h2>%s</h2><hr><ul>", path);
|
|
ws_send(ws_ctx, buf, strlen(buf));
|
|
|
|
struct dirent **names;
|
|
const unsigned num = scandir(fullpath, &names, NULL, alphasort);
|
|
|
|
for (i = 0; i < num; i++) {
|
|
if (!strcmp(names[i]->d_name, ".") || !strcmp(names[i]->d_name, ".."))
|
|
continue;
|
|
|
|
sprintf(buf, "<li><a href=\"%s\">%s</a></li>", names[i]->d_name, names[i]->d_name);
|
|
ws_send(ws_ctx, buf, strlen(buf));
|
|
}
|
|
|
|
sprintf(buf, "</ul></body></html>");
|
|
ws_send(ws_ctx, buf, strlen(buf));
|
|
}
|
|
|
|
static void servefile(ws_ctx_t *ws_ctx, const char *in) {
|
|
char buf[4096], path[4096], fullpath[4096];
|
|
|
|
//fprintf(stderr, "http servefile input '%s'\n", in);
|
|
|
|
if (strncmp(in, "GET ", 4)) {
|
|
wserr("non-GET request, rejecting\n");
|
|
goto nope;
|
|
}
|
|
in += 4;
|
|
const char *end = strchr(in, ' ');
|
|
unsigned len = end - in;
|
|
|
|
if (len < 1 || len > 1024 || strstr(in, "../")) {
|
|
wserr("Request too long (%u) or attempted dir traversal attack, rejecting\n", len);
|
|
goto nope;
|
|
}
|
|
|
|
end = memchr(in, '?', len);
|
|
if (end)
|
|
len = end - in;
|
|
|
|
memcpy(path, in, len);
|
|
path[len] = '\0';
|
|
if (!strcmp(path, "/")) {
|
|
strcpy(path, "/index.html");
|
|
len = strlen(path);
|
|
}
|
|
|
|
wserr("Requested file '%s'\n", path);
|
|
sprintf(fullpath, "%s/%s", settings.httpdir, path);
|
|
|
|
DIR *dir = opendir(fullpath);
|
|
if (dir) {
|
|
closedir(dir);
|
|
dirlisting(ws_ctx, fullpath, path);
|
|
return;
|
|
}
|
|
|
|
FILE *f = fopen(fullpath, "r");
|
|
if (!f) {
|
|
wserr("file not found or insufficient permissions\n");
|
|
goto nope;
|
|
}
|
|
|
|
fseek(f, 0, SEEK_END);
|
|
const unsigned filesize = ftell(f);
|
|
rewind(f);
|
|
|
|
sprintf(buf, "HTTP/1.1 200 OK\r\n"
|
|
"Server: KasmVNC/4.0\r\n"
|
|
"Connection: close\r\n"
|
|
"Content-type: %s\r\n"
|
|
"Content-length: %u\r\n"
|
|
"\r\n",
|
|
name2mime(path), filesize);
|
|
ws_send(ws_ctx, buf, strlen(buf));
|
|
|
|
//fprintf(stderr, "http servefile output '%s'\n", buf);
|
|
|
|
unsigned count;
|
|
while ((count = fread(buf, 1, 4096, f))) {
|
|
ws_send(ws_ctx, buf, count);
|
|
}
|
|
fclose(f);
|
|
|
|
return;
|
|
nope:
|
|
sprintf(buf, "HTTP/1.1 404 Not Found\r\n"
|
|
"Server: KasmVNC/4.0\r\n"
|
|
"Connection: close\r\n"
|
|
"Content-type: text/plain\r\n"
|
|
"\r\n"
|
|
"404");
|
|
ws_send(ws_ctx, buf, strlen(buf));
|
|
}
|
|
|
|
ws_ctx_t *do_handshake(int sock) {
|
|
char handshake[4096], response[4096], sha1[29], trailer[17];
|
|
char *scheme, *pre;
|
|
headers_t *headers;
|
|
int len, i, offset;
|
|
ws_ctx_t * ws_ctx;
|
|
char *response_protocol;
|
|
|
|
// Peek, but don't read the data
|
|
len = recv(sock, handshake, 1024, MSG_PEEK);
|
|
handshake[len] = 0;
|
|
if (len == 0) {
|
|
handler_msg("ignoring empty handshake\n");
|
|
return NULL;
|
|
} else if ((bcmp(handshake, "\x16", 1) == 0) ||
|
|
(bcmp(handshake, "\x80", 1) == 0)) {
|
|
// SSL
|
|
if (!settings.cert) {
|
|
handler_msg("SSL connection but no cert specified\n");
|
|
return NULL;
|
|
} else if (access(settings.cert, R_OK) != 0) {
|
|
handler_msg("SSL connection but '%s' not found\n",
|
|
settings.cert);
|
|
return NULL;
|
|
}
|
|
ws_ctx = alloc_ws_ctx();
|
|
ws_socket_ssl(ws_ctx, sock, settings.cert, settings.key);
|
|
if (! ws_ctx) { return NULL; }
|
|
scheme = "wss";
|
|
handler_msg("using SSL socket\n");
|
|
} else if (settings.ssl_only) {
|
|
handler_msg("non-SSL connection disallowed\n");
|
|
return NULL;
|
|
} else {
|
|
ws_ctx = alloc_ws_ctx();
|
|
ws_socket(ws_ctx, sock);
|
|
if (! ws_ctx) { return NULL; }
|
|
scheme = "ws";
|
|
handler_msg("using plain (not SSL) socket\n");
|
|
}
|
|
offset = 0;
|
|
for (i = 0; i < 10; i++) {
|
|
/* (offset + 1): reserve one byte for the trailing '\0' */
|
|
if (0 > (len = ws_recv(ws_ctx, handshake + offset, sizeof(handshake) - (offset + 1)))) {
|
|
handler_emsg("Read error during handshake: %m\n");
|
|
free_ws_ctx(ws_ctx);
|
|
return NULL;
|
|
} else if (0 == len) {
|
|
handler_emsg("Client closed during handshake\n");
|
|
free_ws_ctx(ws_ctx);
|
|
return NULL;
|
|
}
|
|
offset += len;
|
|
handshake[offset] = 0;
|
|
if (strstr(handshake, "\r\n\r\n")) {
|
|
break;
|
|
} else if (sizeof(handshake) <= (size_t)(offset + 1)) {
|
|
handler_emsg("Oversized handshake\n");
|
|
free_ws_ctx(ws_ctx);
|
|
return NULL;
|
|
} else if (9 == i) {
|
|
handler_emsg("Incomplete handshake\n");
|
|
free_ws_ctx(ws_ctx);
|
|
return NULL;
|
|
}
|
|
usleep(10);
|
|
}
|
|
|
|
if (strchr(settings.basicauth, ':')) {
|
|
const char *hdr = strstr(handshake, "Authorization: Basic ");
|
|
if (!hdr) {
|
|
sprintf(response, "HTTP/1.1 401 Unauthorized\r\n"
|
|
"WWW-Authenticate: Basic realm=\"Websockify\"\r\n"
|
|
"\r\n");
|
|
ws_send(ws_ctx, response, strlen(response));
|
|
free_ws_ctx(ws_ctx);
|
|
return NULL;
|
|
}
|
|
|
|
hdr += sizeof("Authorization: Basic ") - 1;
|
|
const char *end = strchr(hdr, '\r');
|
|
if (!end || end - hdr > 256) {
|
|
free_ws_ctx(ws_ctx);
|
|
return NULL;
|
|
}
|
|
len = end - hdr;
|
|
char tmp[257];
|
|
memcpy(tmp, hdr, len);
|
|
tmp[len] = '\0';
|
|
len = ws_b64_pton(tmp, response, 256);
|
|
|
|
if (len <= 0 || strcmp(settings.basicauth, response)) {
|
|
sprintf(response, "HTTP/1.1 401 Forbidden\r\n"
|
|
"\r\n");
|
|
ws_send(ws_ctx, response, strlen(response));
|
|
free_ws_ctx(ws_ctx);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
//handler_msg("handshake: %s\n", handshake);
|
|
if (!parse_handshake(ws_ctx, handshake)) {
|
|
handler_emsg("Invalid WS request, maybe a HTTP one\n");
|
|
|
|
if (settings.httpdir && settings.httpdir[0])
|
|
servefile(ws_ctx, handshake);
|
|
|
|
free_ws_ctx(ws_ctx);
|
|
return NULL;
|
|
}
|
|
|
|
headers = ws_ctx->headers;
|
|
|
|
response_protocol = strtok(headers->protocols, ",");
|
|
if (!response_protocol || !strlen(response_protocol)) {
|
|
ws_ctx->opcode = OPCODE_BINARY;
|
|
response_protocol = "null";
|
|
} else if (!strcmp(response_protocol, "base64")) {
|
|
ws_ctx->opcode = OPCODE_TEXT;
|
|
} else {
|
|
ws_ctx->opcode = OPCODE_BINARY;
|
|
}
|
|
|
|
if (ws_ctx->hybi > 0) {
|
|
handler_msg("using protocol HyBi/IETF 6455 %d\n", ws_ctx->hybi);
|
|
gen_sha1(headers, sha1);
|
|
snprintf(response, sizeof(response), SERVER_HANDSHAKE_HYBI, sha1, response_protocol);
|
|
} else {
|
|
if (ws_ctx->hixie == 76) {
|
|
handler_msg("using protocol Hixie 76\n");
|
|
gen_md5(headers, trailer);
|
|
pre = "Sec-";
|
|
} else {
|
|
handler_msg("using protocol Hixie 75\n");
|
|
trailer[0] = '\0';
|
|
pre = "";
|
|
}
|
|
snprintf(response, sizeof(response), SERVER_HANDSHAKE_HIXIE, pre, headers->origin,
|
|
pre, scheme, headers->host, headers->path, pre, "base64", trailer);
|
|
}
|
|
|
|
//handler_msg("response: %s\n", response);
|
|
ws_send(ws_ctx, response, strlen(response));
|
|
|
|
return ws_ctx;
|
|
}
|
|
|
|
void proxy_handler(ws_ctx_t *ws_ctx);
|
|
|
|
__thread unsigned wsthread_handler_id;
|
|
|
|
void *subthread(void *ptr) {
|
|
|
|
const struct wspass_t * const pass = ptr;
|
|
|
|
const int csock = pass->csock;
|
|
wsthread_handler_id = pass->id;
|
|
free((void *) pass);
|
|
|
|
ws_ctx_t *ws_ctx;
|
|
|
|
ws_ctx = do_handshake(csock);
|
|
if (ws_ctx == NULL) {
|
|
handler_msg("No connection after handshake\n");
|
|
goto out; // Child process exits
|
|
}
|
|
|
|
proxy_handler(ws_ctx);
|
|
if (pipe_error) {
|
|
handler_emsg("Closing due to SIGPIPE\n");
|
|
}
|
|
out:
|
|
|
|
if (ws_ctx) {
|
|
ws_socket_free(ws_ctx);
|
|
free_ws_ctx(ws_ctx);
|
|
} else {
|
|
shutdown(csock, SHUT_RDWR);
|
|
close(csock);
|
|
}
|
|
handler_msg("handler exit\n");
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void *start_server(void *unused) {
|
|
int csock, pid;
|
|
struct sockaddr_in cli_addr;
|
|
socklen_t clilen;
|
|
|
|
// printf("Waiting for connections on %s:%d\n",
|
|
// settings.listen_host, settings.listen_port);
|
|
|
|
while (1) {
|
|
clilen = sizeof(cli_addr);
|
|
pipe_error = 0;
|
|
pid = 0;
|
|
do {
|
|
csock = accept(settings.listen_sock,
|
|
(struct sockaddr *) &cli_addr,
|
|
&clilen);
|
|
} while (csock == -1 && errno == EINTR);
|
|
|
|
if (csock < 0) {
|
|
error("ERROR on accept");
|
|
continue;
|
|
}
|
|
fprintf(stderr, " websocket %d: got client connection from %s\n",
|
|
settings.handler_id,
|
|
inet_ntoa(cli_addr.sin_addr));
|
|
|
|
pthread_t tid;
|
|
struct wspass_t *pass = calloc(1, sizeof(struct wspass_t));
|
|
pass->id = settings.handler_id;
|
|
pass->csock = csock;
|
|
pthread_create(&tid, NULL, subthread, pass);
|
|
|
|
settings.handler_id += 1;
|
|
}
|
|
handler_msg("websockify exit\n");
|
|
|
|
return NULL;
|
|
}
|