Go言語によるファイル操作機能を学び、ファイルの暗号化、圧縮、アップロード、ダウンロード機能を実装する

go get -u github.com/golang/example/hello/archive/zip
go get -u github.com/golang/example/hello/crypto/aes
go get -u github.com/golang/example/hello/io/ioutil

package main

import (
    "archive/zip"
    "crypto/aes"
    "crypto/cipher"
    "io/ioutil"
    "os"
)

func main() {
    // 读取原始文件
    file, _ := os.Open("original.txt")
    defer file.Close()
    data, _ := ioutil.ReadAll(file)

    // 使用AES加密算法对文件进行加密
    key := []byte("thisisaeskey12345")
    block, _ := aes.NewCipher(key)
    ciphertext := make([]byte, len(data))
    block.Encrypt(ciphertext, data)

    // 创建压缩文件
    zipfile, _ := os.Create("encrypted.zip")
    defer zipfile.Close()
    zipWriter := zip.NewWriter(zipfile)

    // 将加密后的文件写入压缩文件
    zipfiledata, _ := zipWriter.Create("encrypted.txt")
    zipfiledata.Write(ciphertext)

    // 关闭压缩文件
    zipWriter.Close()

    // 读取压缩文件
    zipfile, _ = os.Open("encrypted.zip")
    defer zipfile.Close()
    zipReader, _ := zip.NewReader(zipfile, int64(len(ciphertext)))

    // 解压缩文件
    unzipdata, _ := zipReader.File[0].Open()
    defer unzipdata.Close()
    unzipdatacontent, _ := ioutil.ReadAll(unzipdata)

    // 使用AES解密算法对文件进行解密
    decrypter := cipher.NewCFBDecrypter(block, block.iv)
    plainText := make([]byte, len(unzipdatacontent))
    decrypter.XORKeyStream(plainText, unzipdatacontent)

    // 输出解密后的文件内容
    ioutil.WriteFile("decrypted.txt", plainText, 0644)
}

package main

import (
    "io"
    "net/http"
    "os"
)

func uploadFile(w http.ResponseWriter, r *http.Request) {
    r.ParseMultipartForm(32 << 20) // 设置最大上传文件大小为32MB

    file, handler, err := r.FormFile("file")
    if err != nil {
        w.WriteHeader(http.StatusBadRequest)
        return
    }
    defer file.Close()

    f, err := os.OpenFile(handler.Filename, os.O_WRONLY|os.O_CREATE, 0666)
    if err != nil {
        w.WriteHeader(http.StatusInternalServerError)
        return
    }
    defer f.Close()
    io.Copy(f, file)

    w.WriteHeader(http.StatusOK)
}

func downloadFile(w http.ResponseWriter, r *http.Request) {
    fileName := r.URL.Query().Get("file")
    if fileName == "" {
        w.WriteHeader(http.StatusBadRequest)
        return
    }

    file, err := os.Open(fileName)
    if err != nil {
        w.WriteHeader(http.StatusInternalServerError)
        return
    }
    defer file.Close()

    fi, err := file.Stat()
    if err != nil {
        w.WriteHeader(http.StatusInternalServerError)
        return
    }

    w.Header().Set("Content-Disposition", "attachment; filename="+fileName)
    w.Header().Set("Content-Type", "application/octet-stream")
    w.Header().Set("Content-Length", strconv.FormatInt(fi.Size(), 10))

    io.Copy(w, file)
}

func main() {
    http.HandleFunc("/upload", uploadFile)
    http.HandleFunc("/download", downloadFile)
    http.ListenAndServe(":8080", nil)
}