ensuring HTML emails always show images - html

I have an email sent out in in my application, and in the HTML of that email, i have an <img> tag which is an image and a link.
The problem is that in most cases the image doesn't load in emails, unless you enable the viewing of embedded images.
That image is an important part of the email. Is there any way I can replace the image tag with something else which always loads in emails? The desire is that users don't have to explicitly click on show pictures to see it.

Absolutely... you can embed the image as an attachment, and then use the CID header in the mail MIME to reference it (instead of a URL to a web resource)

There is no way to guarantee that an image will be displayed without explicit permission of the user. That would circumvent the whole concept if it were possible. The idea is to protect the user from exposure to undesirable content. In the event you were to find some hack way around it, it would be considered just that, and could get you blacklisted once the hack is discovered.

Is the img tag just a reference to an external image that's hosted somewhere? You could try adding it to the email as an embedded resource and see if that helps. Some mail clients may still ask permission before displaying it, though. But it should get more of the target audience.

Related

html link: hide href from user

In an HTML file that is sent to someone by e-mail, is it possible to prevent the receiver from inspecting the href of a link in that HTML file?
I need to prevent the user from seeing/copying the url.
You can't. It is entirely impossible.
The email client and the browser are both entirely under the control of the user (so you can't give them a URL without also giving it to the user).
Tricks might obfuscate the URL, but decoding it is trivial.

WhatsApp HTML Sharing Link for Image

I know you can share messages with and this is working on android and ios now:
Share with whatsapp
However I'd like to share an image trough a button on my website like someone would share an image from his phone (gallery). Is this anyhow possible?
One solution that comes to mind is uploading a photo to your server via AJAX, returning the link to the uploaded photo and then sending a message with the link to your photo using the method you described in your question. This is not quite the same as sending an image directly using Whatsapp since the recipient would only receive a link, but I doubt there will ever be a way to send an image to another application from your gallery using a webpage since that would raise some serious concerns.
Roughly, the process would like this (keep in mind that this will require some testing to get right and find a solution that works well on all platforms or at least most of them):
Create an image upload on your website. Simply having <input type="file" accept="image/*"> on your page should, on most platforms, allow you to create a button which will open a dialog to select an image from your phone's gallery when clicked. You can find a full example here or use a library such as Plupload which contains many upload methods, including HTML5 which is what you need.
Create a simple server-side upload. This depends on your language and platform, but all you need to do is store the image somewhere and return a link to it in response. If you don't want to store these images on your server, you could forward it to Imgur API and upload there.
Redirect the user to the whatsapp:// link that contains the image link.
window.location = 'whatsapp://send?text='+encodeURIComponent(imageURL);
This is the point where you need to do some testing on different platforms, though. You might not be able to redirect to a whatsapp:// link this way (since it seems like a security concern), so you may need to trick it (this is a bad idea, but I'm including it for the sake of completeness; the data-action part is from this answer):
var fakeLink = document.createElement('a');
fakeLink.setAttribute('href', 'whatsapp://send?text='+encodeURIComponent(imageURL));
fakeLink.setAttribute('data-action', 'share/whatsapp/share');
fakeLink.click();
In the end, if neither of these work, your best bet is creating a link once the upload is complete for the user to "confirm" sending which actually contains the above whatsapp:// link in the href field.
There are many factors to test and some that are implementation specific so I had to keep it vague without much code - if you come across anything else when implementing this, please mention it in the comments.

How to mask a URL via HTML or .htaccess

I am setting up a website that I want no one to know the URL for. For example, I send them a link that actually goes to the page, but the URL in the bar at the top has a completely different URL that I don't own. I'm not sure if this can be done in PHP, HTML, or the .htaccess file.
This is not possible, unless
you control the systems of the visitors (then you could, for example, change their DNS servers), or
you find and exploit a bug in the browser/system.
You can make a link anchor text look like it leads to a specific domain not under your control, but the real URL will be used in any case. Example: http://wikipedia.org/.

Email Open Tracking: Bypassing an email forwarder that strips the attributes in an image tag?

This may be impossible but I figured I'd give it a shot. If the service that I am using strips the attributes of an image tag => , is there any way that I can get around it?
I tried inserting random unicode characters to break the parser but that failed miserably...
My ultimate goal is to be able to track the email opens and the only way I know how to do that is through an image in the html of the email...
Thanks!
Jonathan
There are many ways to track opens. Like for instance requesting a CSS-file from server, clicking any link, loading a bgsound, or rendering one specific (or any) image. The transparent pixel ist the most common way.
(As I don't see any option to ask for more details besides answering: What service? And what attributes get stripped?)

How to prevent downloading images and video files from my website?

How to prevent downloading images and video files from my website? Is it possible?
What would be the best way to do this?
No, it's not possible.
If you can see it, you can get it.
Don't post them to your site.
Otherwise it is not possible.
As the browser needs to transfer the content to display it (text, images, videos), the data is already on the client's computer when the website is displayed. The previous answers give little advice on how to make it harder for non-experienced users to grab the content. Here are some directions:
General
Overlay the respecitive contents with a transparent <DIV> or a
transparent image (as described in some answers to this question)
Open the website in a frameset, so saving may miss the frame content.
Open the website via window.open() to hide the menu bar.
Disable right-clicks via JavaScript (not recommended due to all the side-effects on usability)
Load the page's HTML code from another file (which may check for a specific referer or which may be ROT13) via JavaScript, so it's harder to access the source code.
Tell the browser that all content is display:none for the printer (something like #media print { body, div, p { display: none } })
Use JavaScript to hide the content before a client makes a screenshot (see Stop User from using “Print Scrn”)
Try to disable or overwrite the clipboard (see this post)
Images
Do not use the <img> tag for images but set the image as background for a <DIV>
Wrap images into SVGs or Flash movies to make them very hard to access in a usable format.
Disable caching for images (via <meta> tag or by setting the appropriate header on server delivery), so they are not stored in the browser cache (immeaditely accessible on the client's computer).
Cut an image into parts, so it takes some extra work to reconstruct the whole image
Add onmousedown events to images, e.g., display a copyright alert.
Deliver the image via server script (e.g., PHP) and check the referer.
Videos
Stream videos to prevent simple downloading via URL.
Wrap videos into a Flash movie.
Use some nasty format that supports DRM.
Texts
Make text unselectable (see How to make HTML Text unselectable)
Additionally to overlaying, wrap the text into JavaScript (e.g., after ROT13 or loaded dynamically from a second file), so the text is not directly available in the source code.
Convert texts to images (this may decrease display quality), SVGs or Flash
Again, I repeat that none of this will stop an experienced user from grabbing the content (e.g. by making a screenshot and - optionally - run OCR on it). Sometimes it's as easy as using the browser's developer tools or using the website without JavaScript. Yet, it will give inexperiences users a hard time, so they may look for some easier source to grab from.
Also keep in mind that the above techniques will affect search engines when reading the page's content (if you're interested in blocking them, start with a robots.txt).
Thank you for any other ideas to complement the above list!
Images must be downloaded in order to be viewed by the client. Videos are a similar case, in many scenarios. You can setup proxy scripts to serve the files out, but that doesn't really solve the issue of preventing the user from getting their own copy. For a more thorough discussion of this topic, see the question How can I prevent/make it hard to download my flash video?
If you are using PHP, the best way is to control it the .htaccess, you need to put your files, images and videos under consideration in a separate folder/directory, and create a new .htaccess file in this directory with the below:
RewriteEngine On
RewriteCond %{REQUEST_URI} \.(mp4|mp3|avi)$ [NC]
RewriteCond %{HTTP_REFERER} !^http://sample.com/.*$ [NC]
RewriteRule ^.* - [F,L]
The first line %{REQUEST_URI} will prevent getting the file through the web browser or through curl.
The second line %{HTTP_REFERER} will prevent accessing the image/video using HTML tags <img> or <video> from any website except the exception ! you provide instead of http://sample.com/ which usually should be your website itself.
You can also have a look at my question and the accepted answer here for more tricks on the browser side.
I'd like to add a more philosophical comment. The whole intent of the internet, particularly the World Wide Web, is to share data. If you don't want people to download a picture/video/document, don't put it on the web. It's really that simple. Too many people think they can impose their own rules on an existing design. Those who want to post content on the web, and control its distribution, are looking to have their cake and eat it too.
In short, no. If someone can view an image or video in their browser then they have, by definition, downloaded it. That's how the web works - it is client server based. Whatever you can view in your browser (client) has been transfered to your computer from the remote website (server).
In standard HTML, I don't know of anyway.
You didn't really say, but I'm guessing you are having problems with people deep linking into your content. If that's the case, and you are open to server side code, I believe this might work:
Create a page that accepts a numeric
id, maps it to a server file path,
opens that file, writes the binary
directly to the response stream.
On the page request, generate a
bunch of random ids, and map them to
the actual media urls, and store that
mapping object server side somewhere
(in session?) with a limited life.
Render your pages with your media
links pointing to the new media page
with the appropriate id as a query
string argument.
Clear the mapping object and generate
all new links on every postback.
This :
won't stop people from downloading
from within your page
definitely isn't as lightweight as standard
HTML
and has it's own set of issues.
But it's a general outline of a workable process which might help you prevent users from deep linking.
As many have said, you can't stop someone from downloading content. You just can't.
But you can make it harder.
You can overlay images with a transparent div, which will prevent people from right clicking on them (or, setting the background of a div to the image will have the same effect).
If you're worried about cross-linking (ie, other people linking to your images, you can check the HTTP referrer and redirect requests which come from a domain which isn't yours to "something else".
you can reduce the possibility but not eliminate it...
It also doesn't hurt to watermark your images with Photoshop or even in Lightroom 3 now. Make sure the watermark is clear and in a conspicuous place on your image. That way if it's downloaded, at least you get the advertising!
This is how I do it in case anyone in the future is wondering.
I put this in the .htaccess file on the root server:
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^http://(www\.)?domain.com/ [NC]
RewriteCond %{HTTP_REFERER} !^http://(www\.)?domain.com.*$ [NC]
RewriteRule \.(mp4|avi)$ - [F]
This stops them from say going to domain.com/videos/myVid.mp4 and then saving it from there.
No it's not. You may block right-clicks and simillar stuff but if someone wants to download it, he will do so, trust me ;)
As soon as they view your page that includes the picture or video, the item is downloaded into the temporary folder of their browser. So if you don't want it downloaded, don't post it.
You can mark folders or files so that they don't have read access (any of the main web servers support this). This allows you to store them on the server without any level of access to the outside world. You may want to do this if you have a service that generates images for someone else to download later, or if you use your web account for FTP access, but don't want anyone to view the files. (i.e. upload a .bak file to the server for someone else to FTP down again).
However, as others have said, getting into copyright areas where people can view the image or video but not save them locally is not fully possibly, although there are tools to discourage illegal usage.
Put your image or video in flash format. Works great.
This is an old post, but for video you might want to consider using MPEG-DASH to obfuscate your files. Plus, it will provide a better streaming experience for your users without the need for a separate streaming server. More info in this post:
How to disable video/audio downloading in web pages?
I believe THEOplayer already provides this sort of solution as a paid service, but I'm not so sure about it.
Granted that any image the user can see will be able to be saved on the computer and there is nothing you can do about it. Now if you want to block access to other images that the user is not supposed to see, I am actually doing it that way:
Every link is to the "src" in your image tag is in fact a request
send to a controller on the server,
the server checks the access
rights of that specific user, and returns the image if the user is
supposed to have access to it,
all images are stored in a directory
that is not directly accessible from the browser.
Benefit:
The user will not have access to anything that you don't intent him/her to have access to
Drawback:
Those requests are slow.. especially is there are lots of images on the same page. I haven't found a good way to accelerate that in fact..
You can set the image to be background image and have a transparent foreground image.
I think the best way is:
STREAM THE VIDEO IN SEPARATED ENCRYPTED PARTS.
There are video hosting services such as vzaar that have this functionality.
As far as I know, that will make it really hard to download directly. At least for 95% of the people.
But of course, if the video plays on the screen people can just use a screen recorder and some simple software to record sound from the audio output (but he/she will have to play the ENTIRE thing to save it, totally inconvenient).
You can't stop image/video theft but you can make harder for normal users but you can't make it harder for the programmers like us (I mean thieves that know little web programming).
There are some tricks you can try:
1.) Using flash as YouTube and many others sites like http://www.funnenjoy.com does.
2.) Div overlaping or background pic setting (but users with little sense can easily save all resources by opening inspect element or other developer option).
3.) You can disable right click and specific keys like CTRL + S and others possibles with JavaScript but main drawback is that if user disable JavaScript our all tricks fail down.
4.) Save image in none online directories (if you have full access to web server) and read that files with server side languages like PHP every time when image / video is required and change image id time to time or create script that can automatically change ID after every access.
5.) Use .htaccess in apache to prevent linking of your images by others sites. you can use this site to automatically generate .htacess http://www.htaccesstools.com/hotlink-protection/
Insert a transparent gif 1px x 1px just inside the <body> tag:
<body><img src="route-to-images/blim.gif" class="blimover">
Then style it with this:
.blimover {
width: 100% !important;
height: 100% !important;
z-index: 1000 !important;
position: absolute !important;
top: 0 !important;
left: 0 !important;
}
This will remove any click functionality from a page, but it sure stops people stealing any content!
You can apply the same to a <div>, <section>, <article> etc, just name accordingly and prevent your copy and/or images being ripped.
Nothing stops a screengrab though ... ...
If you want only authorised users to get the content, both the client and the server need to use encryption.
For video and audio, a good solution is Azure Media Services, which has content protection and encryption. You embed the Azure media player in your browser and it streams the video from Azure.
For documents and email, you can look at Azure Rights Management, which uses a special client. It doesn't currently work in ordinary web browsers, unfortunately, except for one-off, single-use codes.
I'm not sure exactly how secure all this is, however. As others have pointed out, from a security point of view, once those downloaded bytes are in the "attacker's" RAM, they're as good as gone. No solution is 100% secure in this case (please correct me if I'm wrong). As with most security, the goal is to make it harder, so the 99% don't bother.
I think the best way is to prevent right clicking on your webpage, because that is the most convenient way a normal user try to download the content, and you can consider it as remark if u able to do this only as you are never gonna be able to stop a computer geek or hacker people from downloading it, because once the content is on the internet, it means it is in the public domain already...
Put the content on google drive and make it download protect. This way people can only see your documents, pictures but cannot download it.
DRM solutions are available today. It makes the video viewable but not downloadable.
What is DRM?
Digital Rights Management (DRM) solutions are software programs created to help people protect and control their valuable digital content, whether it's documents, videos, images, or audio files.
Check out this. Hope it's helpful.