iOS 3DES 加密，ECB模式，对称加密

import UIKit
import CommonCrypto

class MBA3DESSwift: NSObject {

/// 3DES 加密
/// - Parameters:
///   - data: 需要加密的数据
///   - key: 加密 密钥 24 位长度
/// - Returns: 加密后的数据
@objc class func encrypt(data:Data,key:String) -> Data? {
    
    let keyLength = kCCKeySize3DES + 1
    
    var keyPtr:Array<CChar> = []

    for _:Int in 0 ..< keyLength {
        keyPtr.append(CChar(0))
    }
    
    if key.getCString(&keyPtr, maxLength: keyLength, encoding: .utf8) {
        
        let dataLength:Int = data.count
        
        let bufferSize:Int = dataLength + kCCBlockSize3DES
        
        let buffer = malloc(bufferSize)
        
        var numBytesEncrypted:Int = 0
        
        let bytes = [UInt8](data)
        
        let cryptStatus:CCCryptorStatus = CCCrypt(CCOperation(kCCEncrypt), CCAlgorithm(kCCAlgorithm3DES), CCOptions(ccPKCS7Padding | kCCModeECB) , keyPtr, kCCKeySize3DES, nil, bytes, dataLength, buffer, bufferSize, &numBytesEncrypted)
        
        var outData:Data?
        
        if cryptStatus == kCCSuccess {
            
            outData = Data.init(bytes: buffer!, count: numBytesEncrypted)
        }
        
        free(buffer)
        
        return outData
    }
    
    return nil;
}

/// 3DES 解密
/// - Parameters:
///   - data: 需要解密的数据
///   - key: 解密的密钥 24位
/// - Returns: 解密后的数据
@objc class func decrypt(data:Data,key:String) -> Data? {

    let keyLength = kCCKeySize3DES + 1
    
    var keyPtr:Array<CChar> = []
    
    for _:Int in 0 ..< keyLength {
        keyPtr.append(CChar(0))
    }

    if key.getCString(&keyPtr, maxLength: keyLength, encoding: .utf8) {
        
        let dataLength:Int = data.count
        
        let bufferSize:Int = dataLength + kCCBlockSize3DES
        
        let buffer = malloc(bufferSize)
        
        var numBytesDecrypted:Int = 0
        
        let bytes = [UInt8](data)
        
        let cryptStatus:CCCryptorStatus = CCCrypt(CCOperation(kCCDecrypt), CCAlgorithm(kCCAlgorithm3DES), CCOptions(ccPKCS7Padding | kCCModeECB) , keyPtr, kCCKeySize3DES, nil, bytes, dataLength, buffer, bufferSize, &numBytesDecrypted)
        
        var outData:Data?
        
        if cryptStatus == kCCSuccess {
            
            outData = Data.init(bytes: buffer!, count: numBytesDecrypted)
        }
        
        free(buffer)

        return outData
    }
    
    return nil
}
}

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