When sending data over HTTPS, I know the content is encrypted, however I hear mixed answers about whether the headers are encrypted, or how much of the header is encrypted.
How much of HTTPS headers are encrypted?
Including GET/POST request URLs, Cookies, etc.
All the HTTP headers are encrypted†.
That's why SSL on vhosts doesn't work too well - you need a dedicated IP address because the Host header is encrypted.
†The Server Name Identification (SNI) standard means that the hostname may not be encrypted if you're using TLS. Also, whether you're using SNI or not, the TCP and IP headers are never encrypted. (If they were, your packets would not be routable.)
The headers are entirely encrypted. The only information going over the network 'in the clear' is related to the SSL setup and D/H key exchange. This exchange is carefully designed not to yield any useful information to eavesdroppers, and once it has taken place, all data is encrypted.
New answer to old question, sorry. I thought I'd add my $.02
The OP asked if the headers were encrypted.
They are: in transit.
They are NOT: when not in transit.
So, your browser's URL (and title, in some cases) can display the querystring (which usually contain the most sensitive details) and some details in the header; the browser knows some header information (content type, unicode, etc); and browser history, password management, favorites/bookmarks, and cached pages will all contain the querystring. Server logs on the remote end can also contain querystring as well as some content details.
Also, the URL isn't always secure: the domain, protocol, and port are visible - otherwise routers don't know where to send your requests.
Also, if you've got an HTTP proxy, the proxy server knows the address, usually they don't know the full querystring.
So if the data is moving, it's generally protected. If it's not in transit, it's not encrypted.
Not to nit pick, but data at the end is also decrypted, and can be parsed, read, saved, forwarded, or discarded at will. And, malware at either end can take snapshots of data entering (or exiting) the SSL protocol - such as (bad) Javascript inside a page inside HTTPS which can surreptitiously make http (or https) calls to logging websites (since access to local harddrive is often restricted and not useful).
Also, cookies are not encrypted under the HTTPS protocol, either. Developers wanting to store sensitive data in cookies (or anywhere else for that matter) need to use their own encryption mechanism.
As to cache, most modern browsers won't cache HTTPS pages, but that fact is not defined by the HTTPS protocol, it is entirely dependent on the developer of a browser to be sure not to cache pages received through HTTPS.
So if you're worried about packet sniffing, you're probably okay. But if you're worried about malware or someone poking through your history, bookmarks, cookies, or cache, you are not out of the water yet.
HTTP version 1.1 added a special HTTP method, CONNECT - intended to create the SSL tunnel, including the necessary protocol handshake and cryptographic setup.
The regular requests thereafter all get sent wrapped in the SSL tunnel, headers and body inclusive.
HTTPS (HTTP over SSL) sends all HTTP content over a SSL tunel, so HTTP content and headers are encrypted as well.
With SSL the encryption is at the transport level, so it takes place before a request is sent.
So everything in the request is encrypted.
Yes, headers are encrypted. It's written here.
Everything in the HTTPS message is encrypted, including the headers, and the request/response load.
the URL is also encrypted, you really only have the IP, Port and if SNI, the host name that are unencrypted.
To understand, what is encrypted and what not, you need to know that SSL/TLS is the layer between the transport-layer and the application-layer.
in the case of HTTPS, HTTP is the application-layer, and TCP the transport-layer. That means, all Headers below the SSL-Level are unencrypted. Also, SSL itself may expose data. The exposed data includes(for each layer's Header):
NOTE: Additional Data might be exposed too, but this data is pretty sure to be exposed.
MAC:
Source MAC address(Current Hop)
Destination MAC address(Next Hop)
IP(assuming IPv4):
Destination IP address
Source IP address
IP Options(if set)
Type-Of-Service(TOS)
The number of hops the current packet passed, if TTL is set to 64
TCP:
Source Port
Destination Port
TCP-Options
Theoretically, you can encrypt the TCP-Headers, but that is hard to implement.
SSL:
Hostname(if SNI is being used)
Usually, a browser won't just connect to the destination host by IP immediantely using HTTPS, there are some earlier requests, that might expose the following information(if your client is not a browser, it might behave differently, but the DNS request is pretty common):
DNS:
This request is being sent to get the correct IP address of a server. It will include the hostname, and its result will include all IP addresses belonging to the server.
HTTP:
the first request to your server. A browser will only use SSL/TLS if instructed to, unencrypted HTTP is used first. Usually, this will result in a redirect to the seucre site. However, some headers might be included here already:
User-Agent(Specification of the client)
Host (Hostname)
Accept-Language (User-Language)
Related
I have a Nodejs server that communicates via a REST API with HTTP. I would like now to change the protocol of transmission of all my requests from HTTP to HTTPS. The problem is that I cannot change the client code.
I would like to know if redirecting all HTTP request on the server to https is enough to have the data sent with encryption. Or if I must modify the code that runs on the client and that makes the request with HTTP protocol.
I have to do it because the data should not be sent in clear as there are some sensitive data that are sent (username, password, position information).
Thanks.
The purpose of using HTTPS is not just encryption. It also provides authentication of the server to the client, among others.
One problem with having a client that makes plain http requests (regardless of then being redirected) is that an attacker may create a fake server, to which the client would talk to, revealing secrets or pulling fake data. Without requests being made over https initially, there is nothing to stop an attacker from doing this.
Even worse, an attacker can just listen in to traffic to the real server. If a man-in-the-middle attack is possible (like for example the attacker is on the same local network as either the client or the server), the attacker can hijack the initial plaintext request, talk on HTTPS to the API, then respond on plain http to the client, and so on, for all requests. From the client's perspective, it "just works", from the server's perspective, it's all good, on https.
This is called SSL Stripping.
So the only solution is to have the client do all requests (including the first one) over https. One way to ensure this with browser clients is to use the Strict-Transport-Security (HSTS) response header. For non-browser clients, you can implement them to either comply with HSTS or simply make all requests over https.
If I am running a HTTPS only service, is there any reason not to enable HSTS? Is there a strategy to test HSTS without permanently enabling it or a way "out of" HSTS?
I'd like to add to Mike's answer the warning, that you are probably not running an HTTPS-only service. The reason is that when your server doesn't listen on port 80 then if you only type in the domain and not the protocol (stackoverflow.com instead of https://stackoverflow.com) your browser will not automatically try to connect on port 443 (https) and show a connection error. Thus for most sites an HTTPS only service is out of the question.
The classical way to ensure an https connection by forwarding every http page to an https page via 301/303 forwards is not a sufficient replacement for HSTS. In fact HSTS was build for that case exactly. The reason is that many bookmarks and links will still point to http and every time a user enters a URL without specifying the protocol - which is always - the browser will first try the http connection. An active attacker can hijack that first connection and never forward the user to the https site.
To give you a more vivid image of such an attack imagine a state who spoofs every DNS request to twitter and answers with its own IPs. When it receives an https request it forwards it to twitter without any action (and chance for interception). But when it receives an http request it uses the tool ssl strip Mike has mentioned to transparently forward the content of the connection to twitter's TLS port. Neither the user nor twitter notice that anything is off (except for the very alert users who checks for TLS encryption) but the state has access to every login password.
HSTS can protect those users that have had a legitimate https connection with the server before and have already seen an HSTS header. The header instructs the browser to exchange every http url of the domain with an https url itself (before an http connection is established at all) and deny any unencrypted connection to this domain. Thus in the scenario above almost all users will not end up on the compromised http connection and are safe against the nation wide attack.
From a defense in depth perspective, you should still enable HTTP Strict Transport Policy (HSTS). There are some issues that could crop up in the future that would benefit from HSTS, including:
Server misconfiguration, where HTTP is accidentally turned on. There's one site I visited recently that takes credit card details, it has a HTTPS site but Google links to their HTTP site so depending on how you got there, you could be submitting your details in the clear.
Malicious attacker poisons or hijacks DNS records to redirect the client to their own HTTP-only server, perhaps in conjunction with an ssl strip attack.
You should also ensure a sufficiently long HSTS lifetime, e.g. a year or more.
You can disable support for HSTS by setting the max-age to 0. You'll need to leave this header in place for as long as you had originally set the value. E.g. If you had set it to 2 years, and change your mind, you'll need to leave max-age=0 for at least 2 years (and continue to offer an HTTPS service on that domain) so past clients won't have any issues connecting to it.
Currently, we plan to send a short, and sensitive to a server using GET method. We will append the information, in the GET request string.
We are going to use https.
I was wondering, is there any need for us to perform AES encryption on the data (No decryption needed at received server side. Hence, transferring encryption key over server is not a requirement), before we append it in GET request string?
Is an attacker able to sniff the GET request string, if https is being used?
No, the attacker won't see the GET request string if HTTPS is used.
The TLS/SSL layer gets setup before any of the HTTP traffic is sent across.
If you allow HTTP connections that then immediately forward to HTTPS connections, the GET request will be available in the clear. If you keep HTTPS the entire time, it won't.
That said, there are other reasons not to do this, such as the sensitive data being potentially available in the Web Server access logs.
Here are some similar Q/A threads that will give a good background on the topic:
Is an HTTPS query string secure?
HTTPS, URL path, and query string
Are querystring parameters secure in HTTPS (HTTP + SSL)?
Would like to understand whether the HTTPS body part of the Response is encrypted. Also, in a HTTPS request whether the header are transmitted as plain text / encrypted?
Is there any tool with which I can observe the raw HTTPS traffic without decrypting it.
HTTPS is HTTP over SSL. So the whole HTTP communication is encrypted.
As the other posts say - HTTPS is HTTP (plaintext) wrapped in SSL on top of the TCP/IP layer. Every part of the HTTP message is encrypted. So the stack looks like:
TCP/IP
SSL
HTTP
As far as encryption goes, there is no way to see any part of the HTTP message with SSL around it.
If you need to debug your traffic I suggest the following:
Use a network traffic watcher (like Ethereal) to watch the creation of connections. This will let you see the connection be initiated. It will show you the start of the SSL Handshake, details on failures, and when the session is set up, there will be chains of cipher text. The ciphertext is not very useful, but its presence lets you know data is going back and forth.
Deubg your http layer in the clear prior to setting up HTTPS. Every application or web server I've ever worked with has let me turn off HTTPS, and host the same set of URLs in the clear. Do this, and watch it with the same network tool.
If you get both sides talking with HTTP and everything breaks on HTTPS, it's time to look at either the SSL session establishment or anything in between the two points that may be interrupting the flow.
YES https flow is encrypted. When an https connection is initialized, it uses a strong encryption algorithm to handshake and agree with other part on a less strong, but much faster encryption algorithm for the flow.
To observe network packets, you can use sniffers like http://www.ethereal.com/.
When using HTTPS, the entire content of the request and reply are encrypted, including the headers and body. The HTTP protocol in plaintext happens on top of, TLS or SSL, so what's on the wire is encrypted.
The entire HTTP session is encrypted including both the header and the body.
Any packet sniffer should be able to show you the raw traffic, but it'll just look like random bytes to someone without a deep understanding of SSL, and even then you won't get beyond seeing the key exchange as a third party.
Any packet capture/sniffing tool can show you the raw HTTPS traffic. To view the actual contents (by decrypting it), use Fiddler.
Anything sent over https is encrypted using SSL transport
Try WireShark or Fiddler as helpful tools for this.
This question already has answers here:
Is a HTTPS query string secure?
(9 answers)
Closed 9 years ago.
Suppose I setup a simple php web server with a page that can be accessed by HTTPS. The URL has simple parameters, like https://www.example.com/test?abc=123.
Is it true that the parameter here in this case will be safe from people sniffing the packets? And would this be true if the server does not employ any SSL certificate?
Yes your URL would be safe from sniffing; however, one hole that is easily overlooken is if your page references any third party resources such as Google Analytics, Add Content anything, your entire URL will be sent to the third party in the referer. If its really sensitive it doesn't belong in the query string.
As for your second part of the question, you can't use SSL if you don't have a certificate on the server.
http://answers.google.com/answers/threadview/id/758002.html
HTTPS Establishes an underlying SSL
connection before any HTTP data is
transferred. This ensures that all URL
data (with the exception of hostname,
which is used to establish the
connection) is carried solely within
this encrypted connection, and is
protected from man-in-the-middle
attacks in the same way that any HTTPS
data is.
All HTTP-level transactions within an
HTTPS connection are conducted within
the established SSL session, and no
query data is transferred before the
secure connection is established.
From the outside the only data that is
visible to the world is the hostname
and port you are connecting to.
Everything else is simply a stream of
binary data which is encrypted using a
private key shared only between you
and the server.
In the example you provide your
browser would do this:
Derive
hostname (and port if present)
from URL.
Connect to host.
Check certificate (it must be 'signed'
by a known authority, applied specifically
to correct IP address and port, and be
current).
The browser and server
exchange cryptographic data and the
browser receives a private key.
The
HTTP request is made, and encrypted with
established cryptography.
HTTP response is received. Also encrypted.
HTTP is an 'Application Layer'
protocol. It is carried on top of the
secure layer. According to the SSL
specification, drawn up by Netscape,
it dictates that no application layer
data may be transmitted until a secure
connection is established - as
outlined in the following paragraph:
"At this point, a change cipher spec
message is sent by the client, and the
client copies the pending Cipher Spec
into the current Cipher Spec. The
client then immediately sends the
finished message under the new
algorithms, keys, and secrets. In
response, the server will send its own
change cipher spec message, transfer
the pending to the current Cipher
Spec, and send its finished message
under the new Cipher Spec. At this
point, the handshake is complete and
the client and server may begin to
exchange application layer data."
http://wp.netscape.com/eng/ssl3/draft302.txt
So yes. The data contained in the URL
query on an HTTPS connection is
encrypted. However it is very poor
practice to include such sensitive
data as a password in a 'GET'
request. While it cannot be
intercepted, the data would be logged
in plaintext server logs on the
receiving HTTPS server, and quite
possibly also in browser history. It
is probably also available to browser
plugins and possibly even other
applications on the client computer.
At most a HTTPS URL could be
reasonably allowed to include a
session ID or similar non-reusable
variable. It should NEVER contain
static authentication tokens.
The HTTP connection concept is most
clearly explained here:
http://www.ourshop.com/resources/ssl_step1.html
The requested URI (/test?abc=123) is sent to the web server as part of the HTTP request header and thus encrypted.
However URLs can leak in other ways, usually web browser toolbars, bookmarks, and sending links to friends. POSTing data may be more appropriate depending on the context/sensitivity of the data you're sending.
I believe an HTTPS connection requires an SSL certificate, even a self-generated one if you don't want to buy one.
Hope that helps a bit!
depends on what you mean by safe
SSL encrypts the entire HTTP request/response, so the URL in the GET portion will be encrypted. This does not stop MITM attacks and corruption of the integrity of the SSL session itself. If a non-authoritative certificate is used, this makes potential attack vectors simpler.
Are REST request headers encrypted by SSL?
Is a similar question.
The url:s will be stored both in the server logs and in the browser history so even if they aren't sniffable they are far from safe.
On the wire, yes. At the end points (browser and server) not necessarily. SSL/TLS is transport layer security. It will encrypt your traffic between the browser and the server. It is possible on the browser-side to peek at the data (a BHO for example). Once it reaches the server-side, it is available to the recipient of course and is only as secure as he treats it. If the data needs to move securely beyond the initial exchange and protected from prying eyes on the client, you should also look at message layer security.
The SSL/TSL is a Transport Layer Security, yes the data can be picked with BHO (as #JP wrote) or any add on but also with "out of browser" HTTP sniffers. They read messaging between winsock32 and the application. The encryption takes place in the winsock32 not in the browser.
Take a look (this part was taked from the page of IEinspector):
IEInspector HTTP Analyzer is such a handy tool that allows you to monitor, trace, debug and analyze HTTP/HTTPS traffic in real-time.