The VideoLAN Forums

Posted: **26 Feb 2015 02:00**

I hope I'm in the correct forum with this post!

I'm trying to validate the generated MD5 hash key create by ArtCacheGetDirPath that is used to create the
ArtURL directories/folders.

However I cannot replicate the generated hash using md5sum when using the same input string.

I include the code for ArtCacheGetDirPath with a couple of my printf (debug) lines:

Code: Select all

static char* ArtCacheGetDirPath( const char *psz_arturl, const char *psz_artist,
                                 const char *psz_album,  const char *psz_title )
{
    char *psz_dir;
    char *psz_cachedir = config_GetUserDir(VLC_CACHE_DIR);

    if( !EMPTY_STR(psz_artist) && !EMPTY_STR(psz_album) )
    {
        char *psz_album_sanitized = strdup( psz_album );
        filename_sanitize( psz_album_sanitized );
        char *psz_artist_sanitized = strdup( psz_artist );
        filename_sanitize( psz_artist_sanitized );
        if( asprintf( &psz_dir, "%s" DIR_SEP "art" DIR_SEP "artistalbum"
                      DIR_SEP "%s" DIR_SEP "%s", psz_cachedir,
                      psz_artist_sanitized, psz_album_sanitized ) == -1 )
            psz_dir = NULL;
        free( psz_album_sanitized );
        free( psz_artist_sanitized );
    }
    else
    {
        /* If artist or album are missing, cache by art download URL.
         * If the URL is an attachment://, add the title to the cache name.
         * It will be md5 hashed to form a valid cache filename.
         * We assume that psz_arturl is always the download URL and not the
         * already hashed filename.
         * (We should never need to call this function if art has already been
         * downloaded anyway).
         */
        struct md5_s md5;
        InitMD5( &md5 );
        AddMD5( &md5, psz_arturl, strlen( psz_arturl ) );
	printf("psz_arturl          >%s<\n", psz_arturl);
        if( !strncmp( psz_arturl, "attachment://", 13 ) )
	{
            AddMD5( &md5, psz_title, strlen( psz_title ) );
	   printf("psz_title           >%s<\n", psz_title);
	}
        EndMD5( &md5 );
        char * psz_arturl_sanitized = psz_md5_hash( &md5 );
	printf("psz_artual_sanitized:%s\n", psz_arturl_sanitized);
        if( asprintf( &psz_dir, "%s" DIR_SEP "art" DIR_SEP "arturl" DIR_SEP
                      "%s", psz_cachedir, psz_arturl_sanitized ) == -1 )
            psz_dir = NULL;
        free( psz_arturl_sanitized );
    }
    free( psz_cachedir );
    return psz_dir;
}

When I run vlc and open a youtube video I receive this output:

wallyz@EP45-DS3:~/Downloads/VLC/vlc-2.1.5$ ./vlc
VLC media player 2.1.5 Rincewind (revision 2.1.4-49-gdab6cb5)
[0x1dc0428] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
[0x1dd4db8] main playlist: stopping playback
psz_arturl >https://i.ytimg.com/vi/rO5L_luK1LA/maxresdefault.jpg<
psz_artual_sanitized:db17a3d0c87a9d2a00beefe231aaa3ba
[0x1dd4db8] main playlist: stopping playback
psz_arturl >https://i.ytimg.com/vi/rO5L_luK1LA/maxresdefault.jpg<
psz_artual_sanitized:db17a3d0c87a9d2a00beefe231aaa3ba
psz_arturl >http://i.ytimg.com/vi/rO5L_luK1LA/default.jpg<
psz_artual_sanitized:b0f2893482a1768ccb4fe515b7d17d1e
psz_arturl >http://i.ytimg.com/vi/rO5L_luK1LA/default.jpg<
psz_artual_sanitized:b0f2893482a1768ccb4fe515b7d17d1e
Fontconfig warning: FcPattern object size does not accept value "0"
Fontconfig warning: FcPattern object size does not accept value "0"
Fontconfig warning: FcPattern object size does not accept value "0"
Fontconfig warning: FcPattern object size does not accept value "0"
[0x7f5014001248] main vout display error: Failed to resize display
^Cwallyz@EP45-DS3:~/Downloads/VLC/vlc-2.1.5$ echo "https://i.ytimg.com/vi/rO5L_luK1LA/maxrdefault.jpg" | md5sum
b1a169735e9201e972a58e1ffcaca8bd -
wallyz@EP45-DS3:~/Downloads/VLC/vlc-2.1.5$

The ArtURL is "https://i.ytimg.com/vi/rO5L_luK1LA/maxresdefault.jpg"
which generates the VLC MD5 db17a3d0c87a9d2a00beefe231aaa3ba
however md5sum generates b1a169735e9201e972a58e1ffcaca8bd

Why the discrepancy?

Can anyone help?

Posted: **26 Feb 2015 09:36**

The title?

Posted: **03 Mar 2015 04:15**

The Title doesn't appear to have been used in the construction of the MD5 string otherwise the printf in the conditional code (below) would have displayed it.

if( !strncmp( psz_arturl, "attachment://", 13 ) )
{
AddMD5( &md5, psz_title, strlen( psz_title ) );
printf("psz_title >%s<\n", psz_title);
}

The VideoLAN Forums

Questioning MD5 hash generation for ArtURL

Questioning MD5 hash generation for ArtURL

Re: Questioning MD5 hash generation for ArtURL

Re: Questioning MD5 hash generation for ArtURL