I would save a couple of values (username-password) with NSUserDefault.
First: is there a way to save them together (like in an array for example)?
Second: is it safe? or do I have encrypt the password in a some way?
Encryption will give you some security. The problem is your program would also have to decrypt the password, which means it must have the key stored in it somewhere. This will make it vulnerable to reverse-engineering. A better approach is to use an one-way function (such as a hash) on the password and store that hash value. When a user enters a password, you then apply the one-way function to the password and compare the result to the stored value. In this manner, the password cannot be compromised (well, there's always a dictionary attack, but that's a matter of password strength).
Instead of using NSUserDefaults, you would be better off using iOS Keychain Services. It's main purpose is to securely store user credentials. Apple has already done all the hard work for you. Take advantage of it.
No. It's not safe.
If you need to store data securely, use the keychain.
you can use an NSDictionary or NSarray to save your values, and you should also encrypt your data because NSUserDefaults works like a plist which can be accessed by anyone
This one is easy to use, works with ARC
Related
I used jasypt-1.9.2 to encrypt property value in configuration file.
Unfortunately, I lost key but I have encrypted string and plain text.
In this situation, Is there way to get key from encrypted string and plain text?
If the encryption was not a trivial method the answer is NO.
The best chance you have is to try potential passwords and find one that works.
Note: critical passwords need to be saved securely somewhere that is very hard to loose by accident. One solution is on paper, in a good safe, not a cheap fireproof only safe. Perhaps in a bank Safety Deposit Box.
I am building an iOS app for someone. The app will be used to take mock exams on for a professional license. The question data is stored in Core Data but the question and answers strings need to be encrypted as the client spent a lot of time writing them and doesn't want someone else stealing his work to use in a competing product.
So what I want to do is set the attributes in core data to transformable, use a custom NSValueTransformer to transform the strings to NSData and while they are being transformed use RNEncrypt to encrypt and decrypt.
So far so good.
Here is my predicament: I need to use a key to encrypt and decrypt the data but how do I get/create it?
My options:
hardcode it == bad!
generate key and store in keychain == not the right type of security. i.e.. does not protect against owner of the device.
generate key from user password == no other reason for the user to have to login.
the app connects to a server and gets a key with some authentication stuff(I don't know what is involved exactly) == I don't want to rely on a network connection for the app to work.
obfuscation, I feel like if I create a string from bits of other strings and method sigs and then hash it then that will be enough == It probably won't be.
My questions then are these:
- Obfuscation, can it be enough, has anyone else had success with it?
- From my research I've learnt that a hacker with an ipa can see all the hardcoded strings, class names and method sigs but they can't see the code inside the methods (is that correct?), so how could someone read the key if it was built up/generated inside a method?
- As the title, Can I use Obfuscation?
- Are there any options I have missed?
For the record, if I have to then I'll make people register and login.
You cannot store data locally securely. As soon as you are able to decrypt it an attacker can as well. That goes for EVERY encryption technique. No matter what you try.
You have to store the data or a different decryption key for each data point on a server and retrieve it one by one every time. You additionally have to make sure that the user does not just send 100s of requests and retrieves all data by hand.
Note that storing just one key on a server will result in the exact same thing as writing it hardcoded in the app. And not limiting the requests will just cause the attacker to need a little more time than just looking at an already decrypted local db.
Of course you can obfuscate it to make it seem like it has some good encryption behind it - but if someone WANTS to get the data, he will be able to.
Regarding the code in an ipa: you will not be able to see the original code but you will be able to see some code that produces the same output as the original code. As long as the device can produce the valid key, an attacker can as well.
I do not know if there is a huge community out there that is looking through random apps to steal some of its internal questions / answers / data, I doubt it.
You just have to make the product sooooo good that no competing product with the same data has any chance against it. The data itself can always be "stolen".
I am currently working on an iPhone-App which needs to store an access-token somehow. I am just saving it inside the NSUserdefaults but i dont think it is safest way of persisting sensitive data like this. So my question now is:
What is the best and safest way of storing data like this on an iOS-Device?
I am just saving it inside NSUserDefaults but I don't think it is the safest way of persisting sensitive data like this.
Almost. NSUserDefaults uses plaintext for storing data, so it is insecure. If you want to be a bit safer, you can store the data in the keychain (however, even this considered-to-be-secure storage can be easily dumped...)
I'm working on an app that has a red button. What that means is that every client account has two (secret) keys that are automatically generated. When someone enters those keys on a special (public) page, a certain process will be set in motion. The process is not critical, but
That's all taken care of, the keys are automatically generated on user account creation, stored encryped in the database and are shown to the user once so he can distribute the keys as he sees fit. He can of course reset the keys if he wants to.
The thing is, some clients keep forgetting the keys. Our solution is to reset the keys and redistribute the new keys, but for some clients that's just not practical. I'd like to offer the option of retrieving the keys without resetting them.
My idea was to be able to decrypt the keys using the user's password, meaning that the already logged in user would have to enter his password again, which was used to encrypt the keys and is now used to decrypt them. I'm just not sure how that would technically work (is there an encryption/decryption algorithm that I could use?) and whether there's anything I should consider before employing such a technique.
Does anyone have any ideas on this? Maybe even a better suggestion?
You want to check out ciphers like AES.
I'd check out this gisthub example on how to use Ruby and AES for encryption and decryption.
I am creating a rails application that needs to store a large amount of sensitive data. To assure my customers that the data is being protected, I want to encrypt it on a per-user basis. I have done research looking for gems that can accomplish this. So far I've found strongbox and safe. Together, this would seem to provide a solution for me.
However, I am wondering if this is a common practice. It would seem that most rails applications have some sensitive data to store regarding their users. AuthLogic is handling my password encryption, but emails and other personal data are just as sensitive. Is it common practice to leave these items unencrypted in the database and assume that it will never be compromised? I understand that the database resides in an area that can not communicate with the outside world, but a determined attacker could easily compromise this. Is it common practice for Rails developers leave their data unencrypted and simply trust the security of their web server?
The problem with encrypting your database is that anything you encrypt cannot be used in a SQL query, and also, it still has to be decrypted before it can be used. This means that you need to place the decryption key in close proximity to the database, and in most cases, if someone can compromise your database, that means they have also compromised your decryption key at the same time. Thus the encryption step has bought you very little. With passwords, no decryption is necessary because it's actually a hash function. You're far better off making sure the database is never compromised in the first place.
Always assume that if a hacker can compromise any portion of your security, they can compromise all of it. Chain is only as strong as its weakest link and all that.
Credit card numbers and social security numbers (which fortunately you don't usually need to index on) are probably the most obvious exception to this, but if you have to ask this question, you've got no business storing those items in the first place. There's all kinds of legal trouble you can get into for messing that stuff up.
Credit card number, SSNs, etc should always be stored encrypted.
Passwords should always be stored encrypted, using a one-way hash. This means that when the user supplies a password, you can determine if it matches what you stored in the DB, but given only the encrypted representation in the DB, you cannot from that determine their password, short of brute force/dictionary attacks.
I find that in my app's, I like to add unencrypted_**** readers and writers to my class, to make dealing with the encrypted representation painless.
class User
# has db column encrypted_cc_number
def unencrypted_cc_number
WhateverEncryptionClassYouUse.decrypt(encrypted_cc_number)
end
def unencrypted_cc_number=(val)
self.encrypted_cc_number = WhateverEncryptionClassYouUse.encrypt(val)
end
end
Using layered security mechanisms and strong cryptography is good practice if you are storing a large amount of sensitive data. It is required by the Payment Card Industry’s Data Security Standard (PCI DSS). I suggest that you read the following guideline document: https://www.pcisecuritystandards.org/pdfs/pci_fs_data_storage.pdf.
You should definitely not "assume that it will never be compromised"