Swift 4将字节数组转换为UIImage

那是一个 Base64 编码字符串,以及 Data(base64Encoded:) 可用于对其进行解码,准确给出32个字节:

let keyString = "hpXa6pTJOWDAClC/J6POVTjvJpMIiPAMQiTMjBrcOGw="

if let keyData = Data(base64Encoded: keyString) {
    print(keyData.count) // 32
    print(keyData as NSData) // <8695daea 94c93960 c00a50bf 27a3ce55 38ef2693 0888f00c 4224cc8c 1adc386c>
}

这个 .ignoreUnknownCharacters 选项以忽略未知 @l'l'l:

if let keyData = Data(base64Encoded: keyString, options: .ignoreUnknownCharacters) { ... }

下面的函数将为您提供一个由键字符串生成的32字节数据块。当您使用公共加密库中的AES密钥长度时,我假设您可以访问库的其余部分,并且CC_SHA256()将对您可用

static func sha256Hash(_ string: String) -> Data? {
    let len = Int(CC_SHA256_DIGEST_LENGTH)
    let data = string.data(using:.utf8)!
    var hash = Data(count:len)

    let _ = hash.withUnsafeMutableBytes {hashBytes in
        data.withUnsafeBytes {dataBytes in
            CC_SHA256(dataBytes, CC_LONG(data.count), hashBytes)
        }
    }
    return hash
}