AppleCryptoInteroperability

Cryptographic interoperability between Android and iOS.

This project’s goal is to provide Android equivalents of the cryptographic functions inside Apple’s Security framework for the purpose of easy cryptographic interoperability.

Examples

Signature / Verification

iOS

let plaintext: NSData = ...
let privateKey: SecKey = ...
let publicKey: SecKey = ...
let signature = SecKeyCreateSignature(privateKey, .ecdsaSignatureDigestX962SHA256, plaintext.sha256Digest() as CFData, nil)
let valid = SecKeyVerifySignature(publicKey, .ecdsaSignatureDigestX962SHA256, plaintext.sha256Digest() as CFData, signature as CFData, nil)
XCTAssertTrue(valid)

Android Equivalent

val plaintext: ByteArray = ...
val privateKey: ECPrivateKey = ...
val publicKey: ECPublicKey = ...
val signature = SecKeyCreateSignature(privateKey, SecKeyAlgorithm.ECDSA_SIGNATURE_DIGEST_X962_SHA256, plaintext)
val valid = SecKeyVerifySignature(publicKey, SecKeyAlgorithm.ECDSA_SIGNATURE_DIGEST_X962_SHA256, plaintext, signature)
Assert.assertTrue(valid)

Encryption / Decryption

iOS

let plaintext: NSData = ...
let privateKey: SecKey = ...
let publicKey: SecKey = ...
let encryptedData = SecKeyCreateEncryptedData(publicKey, .eciesEncryptionStandardVariableIVX963SHA256AESGCM, plaintext as CFData, nil)
let decryptedData = SecKeyCreateDecryptedData(privateKey, .eciesEncryptionStandardVariableIVX963SHA256AESGCM, encryptedData as CFData, nil)
XCTAssertTrue(plaintext == decryptedData)

Android

val plaintext: ByteArray = ...
val privateKey: ECPrivateKey = ...
val publicKey: ECPublicKey = ...
val encryptedData = SecKeyCreateEncryptedData(publicKey, SecKeyAlgorithm.ECIES_ENCRYPTION_STANDARD_VARIABLE_IV_X963_SHA256_AES_GCM, plaintext)
val decryptedData = SecKeyCreateDecryptedData(privateKey, SecKeyAlgorithm.ECIES_ENCRYPTION_STANDARD_VARIABLE_IV_X963_SHA256_AES_GCM, encryptedData)
Assert.assertTrue(Arrays.equals(plaintext, decryptedData))

Supported SecKey Algorithms

Signature / Verification

• kSecKeyAlgorithmECDSASignatureDigestX962SHA256

Encryption / Decryption

• kSecKeyAlgorithmECIESEncryptionStandardVariableIVX963SHA256AESGCM

Requirements

Build

This software was built using Android Studio 3.3.2 on macOS 10.14.3 with the Android 28 SDK. You should be able to open the project and run the tests. Note: before running the local unit tests, run the instrumented tests first.

Runtime

Minimum Android 26 SDK

Contributing

Contributions are welcome!

Acknowledgement

This project was inspired by BlueECC.

License

This software is distributed under the terms and conditions of the Apache License 2.0.