snac2-glamour-mirror/snac.c

/* snac - A simple, minimalistic ActivityPub instance */
/* copyright (c) 2022 - 2026 grunfink et al. / MIT license */

#define XS_IMPLEMENTATION

#include "xs.h"
#include "xs_hex.h"
#include "xs_io.h"
#include "xs_unicode_tbl.h"
#include "xs_unicode.h"
#include "xs_json.h"
#include "xs_curl.h"
#include "xs_openssl.h"
#include "xs_socket.h"
#include "xs_unix_socket.h"
#include "xs_url.h"
#include "xs_http.h"
#include "xs_httpd.h"
#include "xs_mime.h"
#include "xs_regex.h"
#include "xs_set.h"
#include "xs_time.h"
#include "xs_glob.h"
#include "xs_random.h"
#include "xs_match.h"
#include "xs_fcgi.h"
#include "xs_html.h"
#include "xs_po.h"
#include "xs_webmention.h"

#include "snac.h"

#include <sys/time.h>
#include <sys/stat.h>
#include <sys/wait.h>

xs_str *srv_basedir = NULL;
xs_dict *srv_config = NULL;
xs_str *srv_baseurl = NULL;
xs_str *srv_proxy_token_seed = NULL;
xs_dict *srv_langs = NULL;

int dbglevel = 0;


int mkdirx(const char *pathname)
/* creates a directory with special permissions */
{
    int ret;

    if ((ret = mkdir(pathname, DIR_PERM)) != -1) {
        /* try to the set the setgid bit, to allow system users
           to create files in these directories using the
           command-line tool. This may fail in some restricted
           environments, but it's of no use there anyway */
        chmod(pathname, DIR_PERM_ADD);
    }

    return ret;
}


xs_str *tid(int offset)
/* returns a time-based Id */
{
    struct timeval tv;

    gettimeofday(&tv, NULL);

    return xs_fmt("%010ld.%06ld", (long)tv.tv_sec + (long)offset, (long)tv.tv_usec);
}


double ftime(void)
/* returns the UNIX time as a float */
{
    xs *ntid = tid(0);

    return atof(ntid);
}


int validate_uid(const char *uid)
/* returns if uid is a valid identifier */
{
    if (!uid || *uid == '\0')
        return 0;

    while (*uid) {
        if (!(isalnum(*uid) || *uid == '_'))
            return 0;

        uid++;
    }

    return 1;
}


void srv_log(xs_str *str)
/* logs a debug message */
{
    if (xs_str_in(str, srv_basedir) != -1) {
        /* replace basedir with ~ */
        str = xs_replace_i(str, srv_basedir, "~");
    }

    xs *tm = xs_str_localtime(0, "%H:%M:%S");
    fprintf(stderr, "%s %s\n", tm, str);

    /* if the ~/log/ folder exists, also write to a file there */
    xs *dt = xs_str_localtime(0, "%Y-%m-%d");
    xs *lf = xs_fmt("%s/log/%s.log", srv_basedir, dt);
    FILE *f;
    if ((f = fopen(lf, "a")) != NULL) {
        fprintf(f, "%s %s\n", tm, str);
        fclose(f);
    }

    xs_free(str);
}


void snac_log(snac *snac, xs_str *str)
/* prints a user debugging information */
{
    xs *o_str = str;
    xs_str *msg = xs_fmt("[%s] %s", snac->uid, o_str);

    if (xs_str_in(msg, snac->basedir) != -1) {
        /* replace long basedir references with ~ */
        msg = xs_replace_i(msg, snac->basedir, "~");
    }

    srv_log(msg);
}


xs_str *hash_password(const char *uid, const char *passwd, const char *nonce)
/* hashes a password */
{
    xs *d_nonce = NULL;
    xs *combi;
    xs *hash;

    if (nonce == NULL) {
        unsigned int r;
        xs_rnd_buf(&r, sizeof(r));
        d_nonce = xs_fmt("%08x", r);
        nonce = d_nonce;
    }

    combi = xs_fmt("%s:%s:%s", nonce, uid, passwd);
    hash  = xs_sha1_hex(combi, strlen(combi));

    return xs_fmt("%s:%s", nonce, hash);
}


int check_password(const char *uid, const char *passwd, const char *hash)
/* checks a password */
{
    int ret = 0;
    xs *spl = xs_split_n(hash, ":", 1);

    if (xs_list_len(spl) == 2) {
        xs *n_hash = hash_password(uid, passwd, xs_list_get(spl, 0));

        ret = (strcmp(hash, n_hash) == 0);
    }

    return ret;
}


int strip_media(const char *fn)
/* strips EXIF data from a file */
{
    int ret = 0;
    const xs_val *v = xs_dict_get(srv_config, "strip_exif");

    if (xs_type(v) == XSTYPE_TRUE) {
        xs *l_fn = xs_tolower_i(xs_dup(fn));

        /* check extensions */
        if (xs_endswith(l_fn, ".jpg") || xs_endswith(l_fn, ".jpeg") ||
            xs_endswith(l_fn, ".png") || xs_endswith(l_fn, ".webp") ||
            xs_endswith(l_fn, ".heic") || xs_endswith(l_fn, ".heif") ||
            xs_endswith(l_fn, ".avif") || xs_endswith(l_fn, ".tiff") ||
            xs_endswith(l_fn, ".gif")  || xs_endswith(l_fn, ".bmp")) {

            const char *mp = xs_dict_get(srv_config, "mogrify_path");
            if (mp == NULL)
                mp = "mogrify";

            xs *cmd = xs_fmt("%s -strip \"%s\" 2>/dev/null", mp, fn);

            ret = system(cmd);

            if (ret != 0) {
                int code = 0;
                if (WIFEXITED(ret))
                    code = WEXITSTATUS(ret);
                
                if (code == 127)
                    srv_log(xs_fmt("strip_media: error stripping %s. '%s' not found (exit 127). Set 'mogrify_path' in server.json.", fn, mp));
                else
                    srv_log(xs_fmt("strip_media: error stripping %s %d", fn, ret));
            }
            else
                srv_debug(1, xs_fmt("strip_media: stripped %s", fn));
        }
    }

    return ret;
}


int check_strip_tool(void)
{
    const xs_val *v = xs_dict_get(srv_config, "strip_exif");
    int ret = 1;

    if (xs_type(v) == XSTYPE_TRUE) {
        const char *mp = xs_dict_get(srv_config, "mogrify_path");
        if (mp == NULL)
            mp = "mogrify";

        xs *cmd = xs_fmt("%s -version 2>/dev/null >/dev/null", mp);
        
        if (system(cmd) != 0)
            ret = 0;
    }

    return ret;
}