swift ASE 加密解密

Swift中提供了ASE加密解密的功能，可以使用CommonCrypto库来实现。下面是一个简单的示例代码：

import CommonCrypto

// 加密函数
func encryptAES(data: Data, key: Data, iv: Data) throws -> Data {
    let cryptLength = size_t(data.count + kCCBlockSizeAES128)
    var cryptData = Data(count: cryptLength)
    var numBytesEncrypted: size_t = 0
    
    let cryptStatus = cryptData.withUnsafeMutableBytes { cryptBytes in
        data.withUnsafeBytes { dataBytes in
            key.withUnsafeBytes { keyBytes in
                iv.withUnsafeBytes { ivBytes in
                    CCCrypt(CCOperation(kCCEncrypt),
                            CCAlgorithm(kCCAlgorithmAES),
                            CCOptions(kCCOptionPKCS7Padding),
                            keyBytes, key.count,
                            ivBytes,
                            dataBytes, data.count,
                            cryptBytes, cryptLength,
                            &numBytesEncrypted)
                }
            }
        }
    }
    
    guard cryptStatus == kCCSuccess else {
        throw NSError(domain: "Encryption Error", code: Int(cryptStatus), userInfo: nil)
    }
    
    cryptData.removeSubrange(numBytesEncrypted..<cryptData.count)
    
    return cryptData
}

// 解密函数
func decryptAES(data: Data, key: Data, iv: Data) throws -> Data {
    let cryptLength = size_t(data.count + kCCBlockSizeAES128)
    var cryptData = Data(count: cryptLength)
    var numBytesDecrypted: size_t = 0
    
    let cryptStatus = cryptData.withUnsafeMutableBytes { cryptBytes in
        data.withUnsafeBytes { dataBytes in
            key.withUnsafeBytes { keyBytes in
                iv.withUnsafeBytes { ivBytes in
                    CCCrypt(CCOperation(kCCDecrypt),
                            CCAlgorithm(kCCAlgorithmAES),
                            CCOptions(kCCOptionPKCS7Padding),
                            keyBytes, key.count,
                            ivBytes,
                            dataBytes, data.count,
                            cryptBytes, cryptLength,
                            &numBytesDecrypted)
                }
            }
        }
    }
    
    guard cryptStatus == kCCSuccess else {
        throw NSError(domain: "Decryption Error", code: Int(cryptStatus), userInfo: nil)
    }
    
    cryptData.removeSubrange(numBytesDecrypted..<cryptData.count)
    
    return cryptData
}

// 使用示例
let plaintext = "Hello, World!"
let key = Data("01234567890123456789012345678901".utf8)
let iv = Data("abcdefghijklmnop".utf8)

let encryptedData = try encryptAES(data: Data(plaintext.utf8), key: key, iv: iv)
print("Encrypted: \(encryptedData.base64EncodedString())")

let decryptedData = try decryptAES(data: encryptedData, key: key, iv: iv)
let decryptedText = String(data: decryptedData, encoding: .utf8)
print("Decrypted: \(decryptedText ?? "")")

上述代码中的`key`和`iv`需要根据实际情况来设置，其中`key`必须是16、24或32字节长度的数据。