ttyd/http.c

#include "server.h"
#include "html.h"

int
check_auth(struct lws *wsi) {
    if (server->credential == NULL)
        return 0;

    int hdr_length = lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_AUTHORIZATION);
    char buf[hdr_length + 1];
    int len = lws_hdr_copy(wsi, buf, sizeof(buf), WSI_TOKEN_HTTP_AUTHORIZATION);
    if (len > 0) {
        // extract base64 text from authorization header
        char *ptr = &buf[0];
        char *token, *b64_text = NULL;
        int i = 1;
        while ((token = strsep(&ptr, " ")) != NULL) {
            if (strlen(token) == 0)
                continue;
            if (i++ == 2) {
                b64_text = strdup(token);
                break;
            }
        }
        if (b64_text != NULL && strcmp(b64_text, server->credential) == 0)
            return 0;
    }

    unsigned char buffer[1024 + LWS_PRE], *p, *end;
    p = buffer + LWS_PRE;
    end = p + sizeof(buffer) - LWS_PRE;

    if (lws_add_http_header_status(wsi, HTTP_STATUS_UNAUTHORIZED, &p, end))
        return 1;
    if (lws_add_http_header_by_token(wsi,
                                     WSI_TOKEN_HTTP_WWW_AUTHENTICATE,
                                     (unsigned char *) "Basic realm=\"ttyd\"",
                                     18, &p, end))
        return 1;
    if (lws_add_http_header_content_length(wsi, 0, &p, end))
        return 1;
    if (lws_finalize_http_header(wsi, &p, end))
        return 1;
    if (lws_write(wsi, buffer + LWS_PRE, p - (buffer + LWS_PRE), LWS_WRITE_HTTP_HEADERS) < 0)
        return 1;

    return -1;
}

int
callback_http(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len) {
    unsigned char buffer[4096 + LWS_PRE], *p, *end;
    char buf[256];
    int n;

    switch (reason) {
        case LWS_CALLBACK_HTTP:
            lwsl_notice("lws_http_serve: %s\n", in);

            {
                char name[100], rip[50];
                lws_get_peer_addresses(wsi, lws_get_socket_fd(wsi), name,
                                       sizeof(name), rip, sizeof(rip));
                sprintf(buf, "%s (%s)", name, rip);
                lwsl_notice("HTTP connect from %s\n", buf);
            }

            if (len < 1) {
                lws_return_http_status(wsi, HTTP_STATUS_BAD_REQUEST, NULL);
                goto try_to_reuse;
            }

            // TODO: this doesn't work for websocket
            switch (check_auth(wsi)) {
                case 1:
                    return 1;
                case -1:
                    goto try_to_reuse;
                case 0:
                default:
                    break;
            }

            // if a legal POST URL, let it continue and accept data
            if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI))
                return 0;

            if (strcmp((const char *) in, "/")) {
                lws_return_http_status(wsi, HTTP_STATUS_NOT_FOUND, NULL);
                goto try_to_reuse;
            }

            p = buffer + LWS_PRE;
            end = p + sizeof(buffer) - LWS_PRE;

            if (lws_add_http_header_status(wsi, 200, &p, end))
                return 1;
            if (lws_add_http_header_by_token(wsi,
                                             WSI_TOKEN_HTTP_CONTENT_TYPE,
                                             (unsigned char *) "text/html",
                                             9, &p, end))
                return 1;
            if (lws_add_http_header_content_length(wsi, index_html_len, &p, end))
                return 1;
            if (lws_finalize_http_header(wsi, &p, end))
                return 1;
            n = lws_write(wsi, buffer + LWS_PRE, p - (buffer + LWS_PRE), LWS_WRITE_HTTP_HEADERS);
            if (n < 0) {
                return 1;
            }

            n = lws_write_http(wsi, index_html, index_html_len);
            if (n < 0)
                return 1;
            goto try_to_reuse;
        case LWS_CALLBACK_HTTP_WRITEABLE:
            lwsl_info("LWS_CALLBACK_HTTP_WRITEABLE\n");
            break;
        default:
            break;
    }

    return 0;

    /* if we're on HTTP1.1 or 2.0, will keep the idle connection alive */
    try_to_reuse:
    if (lws_http_transaction_completed(wsi))
        return -1;

    return 0;
}