How to fetch the expiry date from PKCS12 certificate using iOS security framework?
Alternately can I use openssl? if yes, please point me towards relevant API's
Thanks
Great question! If I were doing this coding, I would first try to think of a solution using Keychain Services.
First, you'd need to fetch the keychain item. Say, via `SecItemCopyMatching()'.
This returns a reference to the found items. Preferably a SecCertificateRef (which is described more in detail in Apple's Keychain Services Reference guide).
I don't see an easy way to explicitly fetch the metadata (or expiration date) from a SecCertificateRef off the top of my head. There's a code snippet I found on books.google.com from "IOS 5 Programming Pushing the Limits: Developing Extraordinary Mobile Apps" called "Checking Certificate Validity" (pages 218 & 219 -- I've linked it for you) which basically checks to see if a certificate allows usage based on matching keys (in their example, it's the subject or domain name; for you, it would be the expiration date). Their technique may help you out.
As for using OpenSSL, I found an answer where you can come up with the expiration date from the command line using the openssl tool. If you can get a handle to your certificate, I'm pretty certain this can be done programmatically as well.
Related
I have a PKCS#11 library that contacts with the vendor's smart card. The low level details are not provided and I'm not interested in them either.
BTW the smart card has no internal certificate associated with it, its just a dumb smart card with a private key store.
So my question is:
What kind of code should I write to obtain a certificate from the PKCS#11 library, or do I need to write such code? does PKCS#11 supports exporting certificates?(I heard openssl supports using 3rd party PKCS#11 libraries. Can I use that to export a certificate from a smart card?)
If the answer to previous question is yes, in what kind of format is the certificate created? What kind of conversions should I to do in order to convert the raw created certificate into office supported format certificate?
and the last question is how to apply that certificate into microsoft office(2013) in order to digitally sign documents? It looks like that office itself doesn't like internal certificates and it keeps requesting us to get one from verisign (?) what's wrong here and how can I force office to use my own created certificate using the aforementioned method?
PKCS#11 interface lets you read ("export") the certificate from the hardware. However you need not just a certificate, but also a private key. Most hardware devices won't let you export a private key. PKCS#11 has a set of functions which let you perform cryptographic operations using private keys stored in the hardware, but not to export those keys.
The certificate is usually exported in native DER format, which can later be put to the PFX file. However without a private key it doesn't make sense.
Unfortunately I don't know what MS Office expects. I assume that Office in your case accepts only certificates which can be validated up to the trusted root certificate.
I have been working on this task to sign a CSR (generated by third party) to be signed by a root CA, which is stored in a token. Sounds like a straightforward job, except that there is a requirement to add a set of extensions as well as subject alternative name to the certificate based on the specification. Since there is no way to alter the CSR to include these information, I assume this should be done during the signing process. However, I have spent lots of time reading the documentations of certutil and certreq to no avail. There seems to be no way to add information for an existing CSR.
Additional information: This has to be done using Microsoft CA due to the limitation of the security token, so OpenSSL is out of question.
I hope someone can help me in this tricky task.
Yes it is possible, check out he below link it is a good starting point
http://blogs.msdn.com/b/alejacma/archive/2011/11/07/how-to-add-subject-alternative-name-to-your-certificate-requests-c.aspx
If I have a password variable that is used for remote SSL authentication, is it secure to store in the source code?
e.g.
NSString * password = #"password";
Are there better way?
Update: Sorry for confusion, I am not storing the user password, instead, I am storing a password that is used to call our own backend, all the app will use the same password.
My new answer:
Try not to use static passwords to access the back-end, period. What happens if somebody you don't want determines what that password is. Why not use usernames & passwords?
You can also consider using a public key or embedded certificate to allow only your app access to the back end servers.
My original answer:
Sounds like you want to get to know the Keychain.
Here's a tutorial that talks about it:
http://maniacdev.com/2011/07/tutorial-how-to-use-the-ios-keychain-to-store-names-and-passwords/
And here is a related question that talks about the security of Keychain under iOS.
You shouldn't have programs a store static password for all users, but instead have each user set up his/her account & password for authentication and then store that stuff in the keychain.
Any text contained within your application is easily extractable. There's no real way around this - using the strings tool, anyone can see any and all text content statically embedded into your app. However, there are some ways around this - notably, if you split up your string into several static strings and concatenate in the right order, it will be much more difficult to reverse engineer the password contained in your app.
I recommend you take a look at a similar question (How Safe is Information Contained within iPhone App Compiled Code), and specifically, my answer to that question, for a more in-depth explanation of what I mean. (Nimrod's comment on that question is also interesting.)
NO!
build your app. Go to the terminal and type strings and then drag your executable to terminal and press return... You'll see your secret password in plain text :)
You should store its hash.
I'm writing an iPhone app that integrates with third party APIs. These APIs use OAuth (key/secret specific to my app not per user) in order to authenticate which app the request is being made in behalf of.
Is it secure (or how secure) is it to simply put the key/secret in code? Can this sort of data be reverse-engineered? Is there a better way to go about including this data in a project?
There is no place on the iPhone to hide data. A user with a jailbroken iPhone has more control over the device than any developer. If possible you should setup a web service such as a REST or SOAP service to take care of these OAuth transactions on behalf of the client.
As Rook said earlier, there is no way to hide your data in iPhone. But you can make hacker job so difficult. I just done a work around for the same issue.
Put oAuth key information in PLIST
Mannually I encrypt this PLIST by using AES key and I got encrypted "CIPHER TEXT"
Modify the AES key by appending characters in between with your own logic. Since it required at runtime to decrypt the plist
Add this modified key with plist "CIPHER TEXT" and store this value in New plist.
Remove old plist which has oAuth information
Now you have only one plist which has encrypted value with modified KEY
Advantage:
Hacking is so difficult since hacker don't have a proper cipher text in plist
To hack this code they should know to separate Modified AES key from Cipher text.
Thou they found Modified AES key, they don't have any clue about the appending algorithm, here i simple used EVEN position of the character, but you can't modify this and you can take 3rd or 4th position of the character. Which is actually will differ for each developer
for more information please visit below link;
https://sites.google.com/site/greateindiaclub/mobil-apps/ios/securelystoringoauthkeysiniosapplication
I'd suggest looking into the Keychain services provided by Apple
http://developer.apple.com/library/ios/#documentation/Security/Conceptual/keychainServConcepts/01introduction/introduction.html
I would like to encrypt a string with AES 256 on the iPhone but have not found much via google. What I am trying to do is post some data to a web site as part of a game I am creating, but I do not want the user to be able to cheat by seeing how it is posted because it is plain text. So I want to post one encrypted string to my php page (ala www.test.com/test.php?encrypted= etc...) and then the php script will decrypt it and do what it needs to if it is valid.
You can just use the CryptoHelper which is adopted by CyrptoExercise Sample Project
A much easier approach here would be to use an HTTPS POST, which would give you similar protections with far less code, though there are still difficulties for solving the problem you're attacking. The kind of solution you're describing generally requires some kind of shared secret, and it's very hard to protect code using a shared secret for long. You may find these posts helpful:
Machine ID for Mac
Store an encryption key in Keychain while application installation process
Obfuscating Cocoa
Still, HTTPS is probably a much better solution than AES here.
Check out this site: http://iphonedevelopment.blogspot.com/2009/02/strong-encryption-for-cocoa-cocoa-touch.html