Swift 加密对称密钥本身

Question

因此，我们希望对 AES 生成的对称密钥本身进行加密，从而实现这种安全性。

基本上是这样的流程： 后端向我们发送密钥 -> 我们创建对称密钥 -> 我们用对称密钥加密数据 -> 我们用后端密钥加密对称密钥 -> 我们将所有内容发送回来。

这是我的尝试，但我预计这里会出现问题。但不知道是什么。预先感谢。

        guard let publicKeyData = Data(base64Encoded: publicKey) else {
            throw EncryptionError.invalidPublicKey
        }

        // Convert the recipient's public key data into a SecKey
        let keyAttributes: [CFString: Any] = [
            kSecAttrKeyType: kSecAttrKeyTypeRSA,
            kSecAttrKeyClass: kSecAttrKeyClassPublic,
            kSecAttrKeySizeInBits: 2048 // Adjust key size as needed
        ]

        guard let key = SecKeyCreateWithData(publicKeyData as CFData, keyAttributes as CFDictionary, nil) else {
            throw EncryptionError.invalidPublicKey
        }

        // Convert the SymmetricKey to Data
        var secretKeyData = Data(count: secretKey.bitCount / 8)
        _ = secretKeyData.withUnsafeMutableBytes { secretKeyDataBuffer in
                secretKey.withUnsafeBytes { secretKeyBuffer in
                    secretKeyDataBuffer.copyBytes(from: secretKeyBuffer)
                }
            }

        // Encrypt the symmetric key using the recipient's public key
        var error: Unmanaged<CFError>?
        guard let encryptedData = SecKeyCreateEncryptedData(
            key,
            .rsaEncryptionOAEPSHA1AESGCM,
            secretKeyData as CFData,
            &error
        ) else {
            if let error = error {
                throw error.takeRetainedValue()
            }
            throw EncryptionError.encryptionFailed
        }

        // Encode the encrypted symmetric key as base64 and return it
        return (encryptedData as Data).base64EncodedString()
    }

Answer 1

使用 CryptoKit 会更好。你还有理由不这么做吗？
例子： 导入 CryptoKit

    let key = Symmetric(data: publicKeyData)
    return key.dataRepresentation