Swift 2 始终解码 base64 return 无

Question

我正在尝试从 base64 解码以下字符串而不退出。它总是 returns 零。我试图将 NSDataBase64DecodingOptions 更改为 IgnoreUnknowCharanters 但它也不起作用。我也试过像这个答案说的那样删除填充 swift base64 decoding returns nil 但是我的字符串的长度可以被 4 整除所以它不起作用。

字符串

PY5ehymWfQKExWxPyOImGiQkxNjyuBREmOXtQdePVpuH9PFzizaO+WTuM1sLouTQPz5UO7csloC9GjOFqkq4POmlB9d3mMJGLB2pVCNs8t9EejOcjV4fRHaITkmfMfVbizCnTvHGBwLWXjLc7gwyhu2+S9qw0NXc5jw6EdEk+zuesrdwLgqws0hDqFSoVw57+CnvUmgXwtNfKP4p64mJ9inH/0xAMarCc5N4Wjz/zmlTyd2PoDFUC/iLdZ7csau7X2M=

选项 1

if let decodedData = NSData(base64EncodedString: base64String, options: NSDataBase64DecodingOptions.IgnoreUnknownCharacters),
        let decodedString = NSString(data: decodedData, encoding: NSUTF8StringEncoding) {
        print(decodedString) // foo
    }

选项 2

 if let decodedData = NSData(base64EncodedString: pnpData, options: NSDataBase64DecodingOptions.init(rawValue: 0)),
        let decodedString = NSString(data: decodedData, encoding: NSUTF8StringEncoding) {
        print(decodedString) // foo
    }

希望你能帮助我。谢谢！！

Answer 1

我怀疑字符串 "PY5ehymWfQKExWxPyOImGiQkxNjyuBREmOXtQdePVpuH9PFzizaO+WTuM1sLouTQPz5UO7csloC9GjOFqkq4POmlB9d3mMJGLB2pVCNs8t9EejOcjV4fRHaITkmfMfVbizCnTvHGBwLWXjLc7gwyhu2+S9qw0NXc5jw6EdEk+zuesrdwLgqws0hDqFSoVw57+CnvUmgXwtNfKP4p64mJ9inH/0xAMarCc5N4Wjz/zmlTyd2PoDFUC/iLdZ7csau7X2M="

这有效，该字符串也进行编码和解码

    let utf8str = "PY5ehymWfQKExWxPyOImGiQkxNjyuBREmOXtQdePVpuH9PFzizaO+WTuM1sLouTQPz5UO7csloC9GjOFqkq4POmlB9d3mMJGLB2pVCNs8t9EejOcjV4fRHaITkmfMfVbizCnTvHGBwLWXjLc7gwyhu2+S9qw0NXc5jw6EdEk+zuesrdwLgqws0hDqFSoVw57+CnvUmgXwtNfKP4p64mJ9inH/0xAMarCc5N4Wjz/zmlTyd2PoDFUC/iLdZ7csau7X2M=".dataUsingEncoding(NSUTF8StringEncoding)
    let base64Encoded = utf8str?.base64EncodedStringWithOptions(NSDataBase64EncodingOptions(rawValue: 0))
    let encodedString : String = base64Encoded!
    print(encodedString) // my encoded data

    let decodedData = NSData(base64EncodedString:  encodedString, options:NSDataBase64DecodingOptions(rawValue: 0))
    let decodedString : String = String(data: decodedData!, encoding: NSUTF8StringEncoding)!
    print(decodedString) // my plain data

这不起作用，解码后的字符串没有得到编码

    let decodedData = NSData(base64EncodedString:  "PY5ehymWfQKExWxPyOImGiQkxNjyuBREmOXtQdePVpuH9PFzizaO+WTuM1sLouTQPz5UO7csloC9GjOFqkq4POmlB9d3mMJGLB2pVCNs8t9EejOcjV4fRHaITkmfMfVbizCnTvHGBwLWXjLc7gwyhu2+S9qw0NXc5jw6EdEk+zuesrdwLgqws0hDqFSoVw57+CnvUmgXwtNfKP4p64mJ9inH/0xAMarCc5N4Wjz/zmlTyd2PoDFUC/iLdZ7csau7X2M=", options:NSDataBase64DecodingOptions(rawValue: 0))
    let decodedString : String = String(data: decodedData!, encoding: NSUTF8StringEncoding)!
    print(decodedString) // my plain data

这可能是原因，检查https://www.base64decode.org/

尽管字符串中不能包含特殊字符。

Answer 2

也许你可以关注这个

https://github.com/krzyzanowskim/CryptoSwift#data-padding

并使用以下方法解码（我猜你的字符串是用aes cbc和base64编码的，如果你想解码这个字符串，你必须知道编码密钥和iv）

"PY5ehymWfQKExWxPyOImGiQkxNjyuBREmOXtQdePVpuH9PFzizaO+WTuM1sLouTQPz5UO7csloC9GjOFqkq4POmlB9d3mMJGLB2pVCNs8t9EejOcjV4fRHaITkmfMfVbizCnTvHGBwLWXjLc7gwyhu2+S9qw0NXc5jw6EdEk+zuesrdwLgqws0hDqFSoVw57+CnvUmgXwtNfKP4p64mJ9inH/0xAMarCc5N4Wjz/zmlTyd2PoDFUC/iLdZ7csau7X2M=".decryptBase64ToString(cipher)

Answer 3

以防万一有人试图解决这个问题，从 Java 转移到 Swift。

这个答案帮了我大忙，您可能需要附加("==")

Swift 3 base64 decode return nil

您可能需要追加("==")

Swift 2 始终解码 base64 return 无

Swift 2 Decode base64 always return nil

base64

decode

swift