Question

我一直在尝试使用Security swift库加密带有椭圆曲线加密的字符串，我在使用SecKeyCreateEncryptedData(...)的行上收到错误：

线程1：EXC_BAD_INSTRUCTION（代码= EXC_I386_INVOP，子代码= 0x0）。

我猜数据的长度和格式不符合所选择的算法，但我在文档中找不到任何关于它的信息。

let attributes: [String: Any] = [kSecAttrKeySizeInBits as String: 256,
                                 kSecAttrKeyType as String: kSecAttrKeyTypeEC,
                                 kSecPrivateKeyAttrs as String: [kSecAttrIsPermanent as String: false]]
var error: Unmanaged<CFError>?
if #available(iOS 10.0, *) {
    guard let privateKey1 = SecKeyCreateRandomKey(attributes as CFDictionary, &error) else {return}

    let publicKey1 = SecKeyCopyPublicKey(privateKey1)
    guard let privateKey2 = SecKeyCreateRandomKey(attributes as CFDictionary, &error) else {return}

    let publicKey2 = SecKeyCopyPublicKey(privateKey2)

    let dict: [String: Any] = [:]

    guard let shared1 = SecKeyCopyKeyExchangeResult(privateKey1, SecKeyAlgorithm.ecdhKeyExchangeStandardX963SHA256, publicKey2!, dict as CFDictionary, &error) else {return}

    guard let shared2 = SecKeyCopyKeyExchangeResult(privateKey2, SecKeyAlgorithm.ecdhKeyExchangeStandardX963SHA256, publicKey1!, dict as CFDictionary, &error) else {return}

    print(shared1==shared2)

    let str = "Hello"
    let byteStr: [UInt8] = Array(str.utf8)
    let cfData = CFDataCreate(nil, byteStr, byteStr.count)

    guard let encrypted = SecKeyCreateEncryptedData(shared1 as! SecKey, SecKeyAlgorithm.eciesEncryptionStandardX963SHA256AESGCM, cfData!, &error) else {return}

    guard let decrypted = SecKeyCreateDecryptedData(shared2 as! SecKey, SecKeyAlgorithm.eciesEncryptionStandardX963SHA256AESGCM, encrypted, &error) else {return}


    print(decrypted)

} else {
    print("unsupported")
}

Answer 1

使用

行

SecKeyCreateEncryptedData(shared1 as! SecKey, SecKeyAlgorithm.eciesEncryptionStandardX963SHA256AESGCM, cfData!, &error)

您强制shared1强制转换为SecKey类型。强制转换（通常）是一个坏主意，在你的情况下它会导致崩溃，因为shared1不是SecKey类型，而是CFData?类型 - 因为那是{{1返回。来自文档：

SecKeyCopyKeyExchangeResult

您可以清楚地看到此函数返回func SecKeyCopyKeyExchangeResult(_ privateKey: SecKey, _ algorithm: SecKeyAlgorithm, _ publicKey: SecKey, _ parameters: CFDictionary, _ error: UnsafeMutablePointer<Unmanaged<CFError>?>?) -> CFData?

使用ios / swift中的椭圆曲线加密来加密数据

1 个答案: