我正在使用一个iOS应用，该应用将从FTPS服务器下载文件。为此，我正在使用库FilesProvider。
直到现在，我已经成功实现了登录服务器，列出文件并搜索文件的操作，但是在尝试下载其中一个文件时出现以下错误：
File Provider <FilesProvider.FTPFileProvider: 0x283c23900> shouldDoOperation Copy with action Copying and destination file:///private/var/mobile/Containers/Data/Application/90AF4202-18C1-4A41-B461-4FB262FD39B9/tmp/B13A8110-C919-48E4-8BD9-E684929310C0.tmp
2020-05-27 14:35:39.372289+0200 MyApp[548:100799] [] nw_socket_handle_socket_event [C13:1] Socket SO_ERROR [54: Connection reset by peer]
2020-05-27 14:35:39.595959+0200 MyApp[548:99892] CFNetwork SSLHandshake failed (-9806)
2020-05-27 14:35:39.596380+0200 MyApp[548:99892] TCP Conn 0x28274f540 SSLHandshake failed (-9806)
File Provider <FilesProvider.FTPFileProvider: 0x283c23900> Failed for operation Copy with action Copying and destination file:///private/var/mobile/Containers/Data/Application/90AF4202-18C1-4A41-B461-4FB262FD39B9/tmp/B13A8110-C919-48E4-8BD9-E684929310C0.tmp
Throwing Error: Error Domain=NSOSStatusErrorDomain Code=-9806 "(null)" UserInfo={_kCFStreamErrorCodeKey=-9806, _kCFStreamErrorDomainKey=3}
FTPFileProvider 是使用我上面提到的用于处理FTP连接的库创建的对象。该提供程序看起来像：
guard let url = URL(string: "ftps://X.X.X.X") else { return } // I have to use an IP address instead of a domain
var provider = FTPFileProvider(baseURL: url, mode: .default, credential: credential, cache: .none)
provider.delegate = self
provider.fileOperationDelegate = self // This delegate is only for print the first line of the error
provider.serverTrustPolicy = .disableEvaluation
创建连接的提供程序之后，我已经能够在服务器上登录，搜索一些文件并获取文件列表。我正在使用此功能：
provider.searchFiles(path: remotePath, recursive: false, query: predicate, foundItemHandler: { (file) in print("File found with name: \(file.name)") }, completionHandler: { (list, error) in
if error != nil {
DispatchQueue.main.async {
onError(error!)
}
} else {
var files:[String] = []
for f in list {
(f.isRegularFile) ? files.append(f.name) : nil
}
DispatchQueue.main.async {
onSucess(files)
}
}
})
运行该搜索时，我收到以下警告：
2020-05-27 14:45:51.831812+0200 MyApp[555:102153] [] nw_socket_handle_socket_event [C4:1] Socket SO_ERROR [54: Connection reset by peer]
但是我成功在onSuccess(files)中获得了输出。 files的返回值为：
["20200527-093234-28346646454.pdf", "20200527-105409-28346646454.pdf"]
在搜索之后，我尝试下载其中一个文件，即当我在本文开头看到错误描述时。对于下载，我具有以下功能：
provider.copyItem(path: "\(remotePath)/\(file)", to: localPath.absoluteString, overwrite: true) { (error) in
if error != nil {
DispatchQueue.main.async {
onError(error!)
}
} else {
DispatchQueue.main.async {
onSuccess(localPath)
}
}
}
Info.plist禁用ATS：<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key> <!-- Because I wan't to allow everything -->
<true/>
<key>NSAllowsLocalNetworking</key> <!-- Because seems like library uses AVFoundation framework -->
<true/>
<key>NSAllowsArbitraryLoadsForMedia</key> <!-- Because I'm using a public IP instead a domain -->
<true/>
</dict>
这两个选项都不起作用。