Our play secret was leaked in source version control system. Few days later our server was compromised and cryptocurrency stolen. Could it be correlated?
What exactly can be done using play secret?
Suppose attacker does not have latest source but an older version and our servers secret, can he do much?
What exactly?
In regards to what one can do with a play secret. The answer is in the documentation
Anyone that can get access to the secret will be able to generate any session they please, effectively allowing them to log in to your system as any user they please. Hence it is strongly recommended that you do not check your application secret into source control. Rather, it should be configured on your production server. This means that it is considered bad practice to put the production application secret in application.conf.
Given that one can get a session and possibly log into your system that way, I would say that it's probably likely that your secret being stolen and then something in your system being stolen a bit afterward is related. That said, the only way you can tell is by auditing your system's logs to try to figure stuff out. Which I don't think anyone but you can do. Best of luck!
It's possible your data has been altered because one can possibly logon to your system because he can generate sessions with access to your play secret (Refer to answer above) you can try checking your logs(which only noob will keep logs.
Try reading this for more insights just in case of next time, be careful
Related
I have been struggling to find a good architecture, or even any nomenclature for what I'm trying to do here. I'm looking for nomenclature so I can have a starting point for research. And I want the same for architecture, but I'll take whatever anyone wants to help with.
What I'm trying to do & learn about
In a nutshell I need my clients to exchange pub keys, and other security data such as ACL ID's, name etc.
Current architectural attempts
I'm currently using my server as a via point, mainly because I can't see any other way of doing this securely and this method uses many layers of security. I also don't know of any other method of going client app to app securely.
A client creates group and sends pub key to server, opens a live query to receive other users data. Other user (with secrets passed to user) queries server for pub key, then sends own data to admin user via server. Admin then sends remainder of own data. I'm leaving out trivial security details but this is the gist of what I'm doing.
Issues
This is really just logical back and forth, but I honestly don't know what I'm doing. I don't even know if what I'm doing is right or the best way, I've also got a crazy infinity loop I'm trying to solve.
I'm looking for some terminology, description and/or architectural pointers, I'll take any input I can get.
Forget terminology, nomenclature and architecture.
Define the problem you are trying to solve in a simple sentence.
Break down the issues into smaller pieces (bite size).
You send A data to server
What happens to the A data
Any feedback or acknowledgement from the target host?
What sort of application is this? Web, Mobile, traditional client/server?
The most elegant solutions are usually the simplest ones.
Sit down and determine whether you have a problem to solve in the first place.
I'm developing an app that's pretty simple, and the important part of it is the content, which consists of lots of info that has been gathered over many years. I want to format it in a nice way to show to the user.
When the user downloads the app and first loads it, it goes to the server to get the whole database into the phone. Then, he can see the important items, and sort/filter through them. To avoid somebody taking my database, I'll use a SSL connection. I know if they want they could use the app to see every piece of content one by one, but there's nothing to do about that.
The thing is: I have the data in the cloud (mine). I can securely download it using an SSL connection (any other ideas to secure the transfer?). When I get it here, I'll save it in a db (Core Data is the obvious choice).
How can I secure the data in the internal database, so if the app is hacked, someone cannot access the db? I would put it in the keychain but it's a rather large db for that and it's not that important. (It's not sensible info, just info I don't want anybody to get massively.)
The other thing I could do is to never store anything in the device and have the user always making calls to the cloud, but I think this would be too time consuming. And just give him the option to save their favorite picks to the device. But that's too time consuming and there is the sync issue.
This is a reference I looked up about a similar issue, without the part I'm asking answered:
How to encrypt iPhone upload and download of info?
Basically, the only choice is to use SqlCipher. Of course, you have to port it to iPhone yourself (unless someone else has posted a port since last I looked). But it's not an insurmountable task.
Of course, even with SqlCipher you have the challenge of storing the key somehow. There's no really secure way to do this -- you have to use some form of "security by obscurity".
Why not just have some private key info stored in the code, and then when you want to download the database just have it query the server with the key? That way you wan't need to worry about SSL or encryption in the downloading part. In regards to storing it I agree with Hot Licks, SqlCipher appears to be the best and only option. However watch out for encryption, as you will have to declare it to apple and get all kinds of export permits (http://stackoverflow.com/questions/2135081/does-my-application-contain-encryption).
Hope this helps,
Jonathan
If I have an app that connects to Amazon's S3 service, is it worth my time to hide/obfuscate the connection strings and API keys? I'm guessing that most hackers won't care all that much, but it would be financially painful if someone found this information and was able to upload data to my account!
For instance, if I store a username/password (or Twitter/Facebook API key and secret), these may be easily found using "strings". A hacker could see the functionality, grab the secrets and use them for nefarious purposes. I've seen people suggest using a simple Rot13, or storing the strings backwards or something like that in the app binary. Are these useful?
Has anyone done this or have any ideas/patterns/code to share?
-dan
You can hide your secrets in a webserver you have full control over, and then having this server relay the query to Amazon. You can then use whatever encryption/validation method you like, since you are not relying on what is supported by Amazon.
Once you have validated that the request is from your own application, you then rewrite the query including your secrets and then forward this to Amazon. The result from Amazon could then be relayed directly back to the application.
In php this could for instance be done using something similar to this snippet (not showing your url rewrite):
$fp = fopen($amazon_url,'r',false);
fpassthru($fp);
fclose($fp);
You dont really need to hide them...what you should do is have an extra key such as a secret, that one IS hidden and is only present in the signature of the call (which can be an MD5 hash or sha (or whatever)) without that secret key people wont be able to just make calls since the signatures created by the server and the offender wont match since they dont know the secret key used...
I'm guessing that most hackers won't
care all that much
It just takes one who's bored enough.
Has anyone done this or have any
ideas/patterns/code to share?
This is what SSL is for. You can encrypt all your transmissions or just the login process (which would return a session id that can be used for subsequent requests during the session).
I am developing an iPhone app together with web services. The iPhone app will use GET or POST to retrieve data from the web services such as http://www.myserver.com/api/top10songs.json to get data for top ten songs for example.
There is no user account and password for the iPhone app. What is the best practice to ensure that only my iPhone app have access to the web API http://www.myserver.com/api/top10songs.json? iPhone SDK's UIDevice uniqueueIdentifier is not sufficient as anyone can fake the device id as parameter making the API call using wget, curl or web browsers.
The web services API will not be published. The data of the web services is not secret and private, I just want to prevent abuse as there are also API to write some data to the server such as usage log.
What you can do is get a secret key that only you know, Include that in an md5 hashed signature, typically you can structure signatures as a s tring of your parameters a nd values and the secret appended at the end, then take the md5 hash of that...Do this both in your client and service side and match the signature string, only if the signatures match do you get granted access...Since t he secret is only present i n the signature it w ill be hard to reverse engineer and crack..
Here's an expansion on Daniel's suggestion.
Have some shared secret that the server and client know. Say some long random string.
Then, when the client connects, have the client generate another random string, append that to the end of the shared string, then calculate the MD5 hash.
Send both the randomly generated string and the hash as parameters in the request. The server knows the secret string, so it can generate a hash of its own and make sure it matches the one it received from the client.
It's not completely secure, as someone could decompile your app to determine the secret string, but it's probably the best you'll get without a lot of extra work.
Use some form of digital signatures in your request. While it's rather hard to make this completely tamper proof (as is anything with regard to security). It's not that hard to get it 'good enough' to prevent most abuse.
Of course this highly depends on the sensitivity of the data, if your data transactions involve million dollar transactions, you'll want it a lot more secure than some simple usage statistic logging (if it's hard enough to tamper and it will gain little to no gain to the attacker except piss you of, it's safe to assume people won't bother...)
I asked an Apple security engineer about this at WWDC and he said that there is no unassailable way to accomplish this. The best you can do is to make it not worth the effort involved.
I also asked him about possibly using push notifications as a means of doing this and he thought it was a very good idea. The basic idea is that the first access would trigger a push notification in your server that would be sent to the user's iPhone. Since your application is open, it would call into the application:didReceiveRemoteNotification: method and deliver a payload of your own choosing. If you make that payload a nonce, then your application can send the nonce on the next request and you've completed the circle.
You can store the UDID after that and discard any requests bearing unverified UDIDs. As far as brute-force guessing of necessary parameters, you should be implementing a rate-limiting algorithm no matter what.
A very cheap way to do this could be getting the iPhone software to send extra data with the query, such as a long password string so that someone can't access the feed.
Someone could reverse engineer what you have done or listen to data sent over the network to discover the password and if bandwidth limitations are the reason for doing this, then a simple password should be good enough.
Of course this method has it's problems and certificate based authentication will actually be secure, although it will be harder to code.
The most secure solution is probably a digital signature on the request. You can keep a secret key inside the iPhone app, and use it to sign the requests, which you can then verify on the server side. This avoids sending the key/password to the server, which would allow someone to capture it with a network sniffer.
A simple solution might be just to use HTTPS - keeping the contents of your messages secure despite the presence of potential eavesdroppers is the whole point of HTTPS. I'm not sure if you can do self-signed certificates with the standard NSURLConnection stuff, but if you have a server-side certificate, you're at least protected from eavesdropping. And it's a lot less code for you to write (actually, none).
I suppose if you use HTTPS as your only security, then you're potentially open to someone guessing the URL. If that's a concern, adding just about any kind of parameter validation to the web service will take care of that.
The problem with most if not all solutions here is that they are rather prone to breaking once you add proxies in the mix. If a proxy connects to your webservice, is that OK? After all, it is probably doing so on behalf of an iPhone somewhere - perhaps in China? And if it's OK for a proxy to impersonate an iPhone, then how do you determine which impersonations are OK?
Have some kind of key that changes every 5 minutes based on an algorithm which uses the current time (GMT). Always allow the last two keys in. This isn't perfect, of course, but it keeps the target moving, and you can combine it with other strategies and tactics.
I assume you just want to dissuade use of your service. Obviously you haven't set up your app to be secure.
Let's say I need to access a web service from an iPhone app. This web service requires clients to digitally sign HTTP requests in order to prove that the app "knows" a shared secret; a client key. The request signature is stored in a HTTP header and the request is simply sent over HTTP (not HTTPS).
This key must stay secret at all times yet needs to be used by the iPhone app.
So, how would you securely store this key given that you've always been told to never store anything sensitive on the client side?
The average user (99% of users) will happily just use the application. There will be somebody (an enemy?) who wants that secret client key so as to do the service or client key owner harm by way of impersonation. Such a person might jailbreak their phone, get access to the binary, run 'strings' or a hex editor and poke around. Thus, just storing the key in the source code is a terrible idea.
Another idea is storing the key in code not a string literal but in a NSMutableArray that's created from byte literals.
One can use the Keychain but since an iPhone app never has to supply a password to store things in the Keychain, I'm wary that someone with access to the app's sandbox can and will be able to simply look at or trivially decode items therein.
EDIT - so I read this about the Keychain: "In iPhone OS, an application always has access to its own keychain items and does not have access to any other application’s items. The system generates its own password for the keychain, and stores the key on the device in such a way that it is not accessible to any application."
So perhaps this is the best place to store the key.... If so, how do I ship with the key pre-entered into the app's keychain? Is that possible? Else, how could you add the key on first launch without the key being in the source code? Hmm..
EDIT - Filed bug report # 6584858 at http://bugreport.apple.com
Thanks.
The goal is, ultimately, restrict access of the web service to authorized users, right? Very easy if you control the web service (if you don't -- wrap it in a web service which you do control).
1) Create a public/private key pair. The private key goes on the web service server, which is put in a dungeon and guarded by a dragon. The public key goes on the phone. If someone is able to read the public key, this is not a problem.
2) Have each copy of the application generate a unique identifier. How you do this is up to you. For example, you could build it into the executable on download (is this possible for iPhone apps)? You could use the phone's GUID, assuming they have a way of calculating one. You could also redo this per session if you really wanted.
3) Use the public key to encrypt "My unique identifier is $FOO and I approved this message". Submit that with every request to the web service.
4) The web service decrypts each request, bouncing any which don't contain a valid identifier. You can do as much or as little work as you want here: keep a whitelist/blacklist, monitor usage on a per-identifier basis and investigate suspicious behavior, etc.
5) Since the unique identifier now never gets sent over the wire, the only way to compromise it is to have physical access to the phone. If they have physical access to the phone, you lose control of any data anywhere on the phone. Always. Can't be helped. That is why we built the system such that compromising one phone never compromises more than one account.
6) Build business processes to accommodate the need to a) remove access from a user who is abusing it and b) restore access to a user whose phone has been physically compromised (this is going to be very, very infrequent unless the user is the adversary).
The simple answer is that as things stand today it's just not possible to keep secrets on the iPhone. A jailbroken iPhone is just a general-purpose computer that fits in your hand. There's no trusted platform hardware that you can access. The user can spoof anything you can imagine using to uniquely identify a given device. The user can inject code into your process to do things like inspect the keychain. (Search for MobileSubstrate to see what I mean.) Sorry, you're screwed.
One ray of light in this situation is in app purchase receipts. If you sell an item in your app using in app purchase you get a receipt that's crypto signed and can be verified with Apple on demand. Even though you can't keep the receipt secret it can be traced (by Apple, not you) to a specific purchase, which might discourage pirates from sharing them. You can also throttle access to your server on a per-receipt basis to prevent your server resources from being drained by pirates.
UAObfuscatedString could be a solution to your problem. From the docs:
When you write code that has a string constant in it, this string is saved in the binary in clear text. A hacker could potentially discover exploits or change the string to affect your app's behavior. UAObfuscatedString only ever stores single characters in the binary, then combines them at runtime to produce your string. It is highly unlikely that these single letters will be discoverable in the binary as they will be interjected at random places in the compiled code. Thus, they appear to be randomized code to anyone trying to extract strings.
If you can bear to be iPhone OS 3.0-only, you may want to look at push notifications. I can't go into the specifics, but you can deliver a payload to Apple's servers along with the notification itself. When they accept the alert (or if your app is running), then some part of your code is called and the keychain item is stored. At this point, that is the only route to securely storing a secret on an iPhone that I can think of.
I had the same question and spent a lot of time poking around for an answer. The issue is a chicken and egg one: how to pre-poluate the keychain with data needed by your app.
In any case, I found a technique that at least will make it harder for a jailbreaker to uncover the information - they'll at least have to disassemble your code to find out what you did to mask the info:
String Obfuscation (if the link breaks search for "Obfuscate / Encrypt a String (NSString)")
Essentially the string is obfuscated before placed in the app, then you unobfuscate it using code.
Its better than doing nothing.
David
EDIT: I actually used this in an app. I put a base coding string into the info.plist, then did several operations on it in code - rot13, rotate/invert bytes, etc. The final processed string was used to decode the obfuscated string. Now, the three letter agencies could for sure break this - but at a huge cost of many hours decoding the binary.
I was going to say that this is the best technique I've come across, but I just read Kiran's post on UAObfuscatedString (different answer), which is a completely different way to obfuscate. It has the benefit of no strings saved anywhere in the app - each letter is turned into a method call. The selectors will show up as strings, so a hacker can quickly tell that your class used that technique though.
I think that this similar question, and my answer, may be relevant to your case too. In a nutshell, there was some talk of a trusted platform module being present in an iPhone. This would allow your service to trust an iPhone, even in the hands of an attacker. However, it looks like using the keychain is your best bet.
Did you consider/try the Push Notification suggestion, for initially transmitting the secret to the app & keychain? Or end up finding some other method to achieve this?
I'm going have my iphone app upload images to Amazon S3. Instead of putting the AWS credentials in the app, I am going to have the app phone home to my server for the URI and headers to use in the S3 upload request. My server will generate the S3 URI, proper signatures, etc. I can then implement a tighter, more specific security model on my app's webservice than AWS offers by itself and not give away my AWS keys to anyone with a jailbroken iphone.
But there still has to be some trust (credentials or otherwise) given to the app, and that trust can be stolen. All you can ever do is limit the damage done if someone jailbreaks an iphone and steals whatever credentials are in the app. The more powerful those credentials are, the worst things are. Ways to limit the power of credentials include:
avoid global credentials. make them per-user/application
avoid permanent credentials. make them temporary if possible
avoid global permissions. give them only the permissions they need. for instance, write permissions might be broken down into insert, overwrite, delete, write against resource group A or B, etc, and read could be broken into read named resources, read a list of all existing resources, read resource groups A or B, etc.
I would recommend creating a key at run time if possible. This way if the key were to get apprehended during a particular session, once the session ends, the key will be worthless. They could still apprehend the key from memory if they are smart enough, but it wouldn't matter since the key would become invalid after a period of time.
Sounds wonky. Would use HTTPS and maybe an encryption package to handle the key.
I think CommonCrypto is available for iPhone.
EDIT: Still sounds wonky. Why would anyone pass a secret key in an HTTP header? Anyone who traces your network traffic (via a logging wifi router, for instance) would see it.
There are well-established security methods for encrypting message traffic...why not use them rather than invent what is basically a trivially flawed system?
EDIT II: Ah, I see. I would go ahead and use the Keychain...I think it is intended for just these kinds of cases. I missed that you were generating the request using the key. Would still use HTTPS if I could though, since that way you don't risk people deducing your keygeneration scheme via inspection of enough signatures.