英文:
Encode/Decode base64
问题
这是我的代码，我不明白为什么解码函数不起作用。
请给予一些见解，谢谢。
func EncodeB64(message string) (retour string) {base64Text := make([]byte, base64.StdEncoding.EncodedLen(len(message)))base64.StdEncoding.Encode(base64Text, []byte(message))return string(base64Text)}func DecodeB64(message string) (retour string) {base64Text := make([]byte, base64.StdEncoding.DecodedLen(len(message)))base64.StdEncoding.Decode(base64Text, []byte(message))fmt.Printf("base64: %s\n", base64Text)return string(base64Text)}
它给了我以下输出：
[解码错误 - 输出不是utf-8][解码错误 - 输出不是utf-8]
英文:
here is my code and I don't understand why the decode function doesn't work.
Little insight would be great please.
func EncodeB64(message string) (retour string) {base64Text := make([]byte, base64.StdEncoding.EncodedLen(len(message)))base64.StdEncoding.Encode(base64Text, []byte(message))return string(base64Text)}func DecodeB64(message string) (retour string) {base64Text := make([]byte, base64.StdEncoding.DecodedLen(len(message)))base64.StdEncoding.Decode(base64Text, []byte(message))fmt.Printf("base64: %s\n", base64Text)return string(base64Text)}
It gaves me :
[Decode error - output not utf-8][Decode error - output not utf-8]
答案1
得分: 58
The len prefix is superficial and causes the invalid utf-8 error:
package mainimport ("encoding/base64""fmt""log")func main() {str := base64.StdEncoding.EncodeToString([]byte("Hello, playground"))fmt.Println(str)data, err := base64.StdEncoding.DecodeString(str)if err != nil {log.Fatal("error:", err)}fmt.Printf("%q\n", data)}
(Also here)
Output
SGVsbG8sIHBsYXlncm91bmQ="Hello, playground"
EDIT: I read too fast, the len was not used as a prefix. dystroy got it right.
英文:
The len prefix is superficial and causes the invalid utf-8 error:
package mainimport ("encoding/base64""fmt""log")func main() {str := base64.StdEncoding.EncodeToString([]byte("Hello, playground"))fmt.Println(str)data, err := base64.StdEncoding.DecodeString(str)if err != nil {log.Fatal("error:", err)}fmt.Printf("%q\n", data)}
(Also here)
Output
SGVsbG8sIHBsYXlncm91bmQ="Hello, playground"
EDIT: I read too fast, the len was not used as a prefix. dystroy got it right.
答案2
得分: 34
DecodedLen 返回的是最大长度。
这个长度对于调整缓冲区的大小很有用，但是缓冲区的一部分不会被写入，因此不会是有效的 UTF-8。
你必须只使用 Decode 函数返回的实际写入长度。
l, _ := base64.StdEncoding.Decode(base64Text, []byte(message))log.Printf("base64: %s\n", base64Text[:l])
英文:
DecodedLen returns the maximal length.
This length is useful for sizing your buffer but part of the buffer won't be written and thus won't be valid UTF-8.
You have to use only the real written length returned by the Decode function.
l, _ := base64.StdEncoding.Decode(base64Text, []byte(message))log.Printf("base64: %s\n", base64Text[:l])
答案3
得分: 27
func base64Encode(str string) string {
return base64.StdEncoding.EncodeToString([]byte(str))
}
func base64Decode(str string) (string, bool) {
data, err := base64.StdEncoding.DecodeString(str)
if err != nil {
return "", true
}
return string(data), false
}
英文:
To sum up the other two posts, here are two simple functions to encode/decode Base64 strings with Go:
// Dont forget to import "encoding/base64"!func base64Encode(str string) string {return base64.StdEncoding.EncodeToString([]byte(str))}func base64Decode(str string) (string, bool) {data, err := base64.StdEncoding.DecodeString(str)if err != nil {return "", true}return string(data), false}
答案4
得分: 3
@Denys Séguret的答案几乎100%正确。为了避免在base64Text中浪费未使用的空间，你应该使用base64.DecodedLen。看一下base64.DecodeString如何使用它。
代码应该是这样的：
func main() {message := base64.StdEncoding.EncodeToString([]byte("Hello, playground"))base64Text := make([]byte, base64.StdEncoding.DecodedLen(len(message)))n, _ := base64.StdEncoding.Decode(base64Text, []byte(message))fmt.Println("base64Text:", string(base64Text[:n]))}
在这里尝试一下。
英文:
@Denys Séguret's answer is almost 100% correct. As an improvement to avoid wasting memory with non used space in base64Text, you should use base64.DecodedLen. Take a look at how base64.DecodeString uses it.
It should look like this:
func main() {message := base64.StdEncoding.EncodeToString([]byte("Hello, playground"))base64Text := make([]byte, base64.StdEncoding.DecodedLen(len(message)))n, _ := base64.StdEncoding.Decode(base64Text, []byte(message))fmt.Println("base64Text:", string(base64Text[:n]))}
Try it here.
答案5
得分: 3
func (s secure) encodePayload(body []byte) string {
//Base64编码
return base64.StdEncoding.EncodeToString(body)
}
func (s secure) decodePayload(body []byte) ([]byte, error) {
//Base64解码
b64 := make([]byte, base64.StdEncoding.DecodedLen(len(body)))
n, err := base64.StdEncoding.Decode(b64, body)
if err != nil {
return nil, err
}
return b64[:n], nil
}
英文:
More or less like above, but using []bytes and part of a bigger struct:
func (s secure) encodePayload(body []byte) string {//Base64 Encodereturn base64.StdEncoding.EncodeToString(body)}func (s secure) decodePayload(body []byte) ([]byte, error) {//Base64 Decodeb64 := make([]byte, base64.StdEncoding.DecodedLen(len(body)))n, err := base64.StdEncoding.Decode(b64, body)if err != nil {return nil, err}return b64[:n], nil}
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