Hi there,

Do you know if iOS supports Public Key decryption?

My use case needs me to encrypt some data with the private key, and decrypt it with the public key. The opposite of normal operation

All the best!

Johnny

I'm trying this:

let privateKey = "my-own-secp256k1-key-in-hex".dataFromHexadecimalString()
let publicKey = "my-own-secp256k1-key-in-hex".dataFromHexadecimalString()

But then I get a CC.CCError.memoryFailure with:

let shared = try CC.EC.computeSharedSecret(privateKey, publicKey: publicKey)

It doesn't happen when I import keys that have been generated with:

let pair = try! CC.EC.generateKeyPair(256)
let privateKey = pair.0.hex.dataFromHexadecimalString()
let publicKey = pair.1.hex.dataFromHexadecimalString()
let shared = try CC.EC.computeSharedSecret(privateKey, publicKey: publicKey)

Instead of use CC.EC.generateKeyPair to get a keypair.

• How can I import my own keypair? Is it supported?
• What kind of EC keys are generated by default?

Tests pass, except testUpsert and testDel. They fail on my machine: function SecItemAdd inside of SwKeyStore.upsertKey method returns status -34018. This happens before and after migration.

I don't have a Swift5, Xcode 10.2, OS X 10.14 compatible Mac, and I don't want to buy one only for this project.

If you want to be a SwCrypt maintainer, please apply here.

Responsibilities:

• Review, test, accept pull requests
• Release new versions, push them to cocoapods
• If you want, you can write better documentation or you can add new features.

Rules:

• My GitHub account (@soyersoyer) should continue to be one of the owners of the project, but you will have full control over its future direction.

The getAES128Key and getAES256Key methods are prone to brute-force attacks. Basically the key is computed as MD5(password + iv[0..7]). Given that the IV is a public info, the implementation can be reduced to MD5(password).

MD5 is a very fast hashing function and is also vulnerable to collisions. This means that an attacker can compute hashes fast and also needs to search a smaller space.

But even if the IV was not public, or if another hashing function would have been used (e.g. SHA2) the issue remains.

The key derivation should be based on a password based key derivation function such as bcrypt or PBKDF2 (with high number of iterations).

Xcode: 9.3.1 Code:

let data = "Hello Test".data(using: .utf8)!
let (privateKey, publicKey) = try! CC.RSA.generateKeyPair(1024)
// encrypt
let encrypted = try! CC.RSA.encrypt(data, derKey: publicKey, tag: Data(), padding: .pkcs1, digest: .none)
// decrypt
do {
    let (decrypted,_) = try CC.RSA.decrypt(encrypted, derKey: privateKey, tag: Data(), padding: .pkcs1, digest: .none)
    print("decrypted:\(String(data:decrypted, encoding:.utf8)!)")
}catch{
    print("decrypt fail")
}

decypt failure on Simulator:iPhone 5s 8.1,but success on Simulator: iPhone SE 11.3.

CCCryptorStatus 
CCRSACryptorDecrypt(
    CCRSACryptorRef privateKey, 
    CCAsymetricPadding padding, 
    const void *cipherText, 
    size_t cipherTextLen,
    void *plainText, 
    size_t *plainTextLen, 
    const void *tagData, 
    size_t tagDataLen, 
    CCDigestAlgorithm digestType)
__OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_5_0);

It should be support iOS 5.0 and upper,But why decrypt failure on iOS 8.1?

Hi, I am using SwCrypt to implement GCM in my app. Below is the list of Parameter values I pass: opMode: .encrypt algorithm: .aes data: stringToEncrypt.data(using: .utf8)! key: keyString.data(using: .utf8)! iv: Random data of length 12 bytes aData: Random data of length 20 bytes (I'm not sure what this parameter is for) tagLength: 128

I get the error [crypt(_:algorithm:data:key:iv:aData:tagLength:)] AppName.CC.CCError: paramError (-4300) I am unable to understand which parameter I am passing with wrong value

Hey there,

I've been using your swcrypt code in my app. Its very useful, so thank you very much. Its the only one that seems to include both pub key and symmetric algs together, without forcing me to use the keychain (like Heimdall does).

However I was signing some data and found that the signature kept failing.

Your doc says:

        let sign = try? CC.RSA.sign(testMessage, derKey: privKey, padding: .pss,  digest: .sha256, saltLen: 16)

         let verified = try? CC.RSA.verify(testMessage, derKey: pubKey, padding: .pss, digest: .sha256, saltLen: 16, signedData: sign!)

which kind of implies that you pass the message data in to the sign and verify function. But I found it fails with more than about 100 bytes. Looking at your code for sign, the first parameter is actually:

        func sign(hash: NSData, derKey: NSData...

It seems that the code is actually used to sign a hash rather than to sign raw data. Do your sample code probably should be something like this:(from my unit tests)

        let data = randomLargeData(10240)

        let hash = CC.digest(data, alg: .sha256)

        let sign = try? CC.RSA.sign(hash, derKey: privateKey, padding: .pkcs1,
                                    digest: .sha256)

        XCTAssertNotNil(sign, "Failed to sign")

        let verified = try? CC.RSA.verify(hash, derKey: publicKey, padding: .pkcs1, digest: .sha256, signedData: sign!)

        XCTAssertNotNil(verified, "Failed to calculate verification")

        XCTAssertTrue(verified!, "Failed to verify")

This raises a question... why are we passing a digest name to the signing function? Is it required? The call to CCRSACryptorSign does seem to require it, but why? Does the digest passed in to sign() need to be the same as the digest used to hash the message?

Also... note that your doc indicates "padding: .pss". That doesn't exist. lastly the saltLen parameter is no longer used.

Again... thanks for the library.

• Added Package.swift
• Updated README.md with SPM instructions
• Updated .gitignore for swiftpm folder

A new release would need to be created for SPM to see the manifest. Or just change my instructions in the readme to have them select the master branch when importing package.

since Apple just formally released Swift 4.1, I have found this library has some compile warnings. SwCrypt.swift:742:18: Overlapping accesses to 'result', but modification requires exclusive access; consider copying to a local variable

Hello, everyone! Can you please help me to use SwCrypt?

The task is to:

1. Generate public and private keys
2. Covert them to String format
3. Encrypt some other string with a public key and receive another string as result of encryption
4. Decrypt string received at the previous step with the private key

To be honest, I'm new in cryptography and know a little about it's principles. Are actions mentioned above possible?

I've read all the issues and still can't get how to use the library.

1. I've generated public and private keys with. let (privateKey, publicKey) = try! CC.RSA.generateKeyPair(512) let privKeyStr = privateKey.base64EncodedString() let pubKeyStr = publicKey.base64EncodedString()

2. I have a string which i want to encode and than decode let testString: String = "Test string"

3. Trying to encode it: let testStringData = testString.data(using: .utf8)! let pubKeyData = pubKeyStr.data(using: .utf8)! let tagStr = "L" //still can't get what should I use there let tag = tagStr.data(using: .utf8)! let encryptedData = try! CC.RSA.encrypt(testStringData, derKey: pubKeyData, tag: tag, padding: .oaep, digest: .sha1)

4. Get an error:

CCError: decodeError (-4304)

Can you please help me to use the library? Thanks!

I am using an external library that expects RSA based private/public key pair in SecKey format. I couldn't find a way to convert DER based key pair in SecKey format properly. Any help would be highly appreciated?

Application using SwCrypt crashing on ref = CCDHCreate!(kCCDHRFC3526Group5!)

In the following Code "fileprivate static let kCCDHRFC3526Group5M: kCCDHRFC3526Group5TM? = getFunc(dl!, f: "kCCDHRFC3526Group5") fileprivate static let kCCDHRFC3526Group5 = kCCDHRFC3526Group5M?.pointee"

kCCDHRFC3526Group5M value is nil on iPadOS 15.4 and 15.4.1 value is correctly calculated in iPadOS 14.x

hi, after generate keypair, i test with this website https://www.devglan.com/online-tools/rsa-encryption-decryption, it's success encrypt but fail to decrypt. You can see image here

if using keypair from this website, it's work normally, can u explain why it's not working?

String representation of Android RSA keys does not make use of standard PEM headers. In order to simplify export / import of public keys to / from Android, PEM headers should be made optional. A first step is opening up the add / strip header functions.