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reorg handler to make it easier to read
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@w3irdrobot
w3irdrobot committed Feb 16, 2023
1 parent 1b5257d commit 7a939ac
Showing 1 changed file with 77 additions and 65 deletions.
142 changes: 77 additions & 65 deletions handlers.go
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Original file line number Diff line number Diff line change
Expand Up @@ -5,8 +5,10 @@ import (
"crypto/sha256"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"io"
"mime/multipart"
"net/http"
"net/url"
"os"
Expand All @@ -27,38 +29,18 @@ type response struct {

func upload(baseDir, domain string, pubkeys []string) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
r.Body = http.MaxBytesReader(w, r.Body, MAX_UPLOAD_SIZE)
if err := r.ParseMultipartForm(MAX_UPLOAD_SIZE); err != nil {
http.Error(w, "file too big. must be under 5MB", http.StatusBadRequest)
return
}

file, fileHeader, err := r.FormFile("file")
file, fileHeader, err := getFileFromRequestBody(w, r)
if err != nil {
logrus.WithError(err).Error("error getting file from request")
http.Error(w, "file not found in request", http.StatusBadRequest)
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
defer file.Close()

// make buffer used to detect content type
buff := make([]byte, 512)
if _, err := file.Read(buff); err != nil {
logrus.WithError(err).Error("error reading 512 bytes from file in request")
http.Error(w, "unable to read file for mime detection", http.StatusInternalServerError)
return
}

filetype := http.DetectContentType(buff)
if filetype != "image/jpeg" && filetype != "image/png" {
http.Error(w, "invalid format. only jpeg and png are accepted", http.StatusBadRequest)
return
}
pubkey := r.FormValue("pubkey")
signature := r.FormValue("signature")
logrus.WithFields(logrus.Fields{"pubkey": pubkey, "signature": signature}).Debug("form values")

// seek back to beginning to get whole file
if _, err := file.Seek(0, io.SeekStart); err != nil {
logrus.WithError(err).Error("error seeking to beging of file")
http.Error(w, "unable to process the file", http.StatusInternalServerError)
if len(pubkeys) > 0 && !pubkeyIsApproved(pubkey, pubkeys) {
http.Error(w, "pubkey not approved", http.StatusUnauthorized)
return
}

Expand All @@ -71,15 +53,6 @@ func upload(baseDir, domain string, pubkeys []string) http.HandlerFunc {
}
shasum := sha256.Sum256(buf.Bytes())

pubkey := r.FormValue("pubkey")
signature := r.FormValue("signature")
logrus.WithFields(logrus.Fields{"pubkey": pubkey, "signature": signature}).Debug("form values")

if len(pubkeys) > 0 && !pubkeyIsApproved(pubkey, pubkeys) {
http.Error(w, "pubkey not approved", http.StatusUnauthorized)
return
}

validSig, err := checkSignature(pubkey, signature, shasum[:])
if err != nil {
logrus.WithError(err).Error("error checking the signature")
Expand All @@ -91,40 +64,12 @@ func upload(baseDir, domain string, pubkeys []string) http.HandlerFunc {
return
}

// create directory path to put file
directory := createAndGetDirectory(shasum[:])
fullDirectory := filepath.Join(baseDir, directory)
if err := os.MkdirAll(fullDirectory, os.ModePerm); err != nil {
logrus.WithError(err).Error("error creating the directory on filesystem")
http.Error(w, "error preparing the file", http.StatusInternalServerError)
return
}

// get name and paths to file
extension := filepath.Ext(fileHeader.Filename)
name := fmt.Sprintf("%s%s", hex.EncodeToString(shasum[:]), extension)
filePath := filepath.Join(directory, name)
fullPath, err := filepath.Abs(filepath.Join(fullDirectory, name))
if err != nil {
logrus.WithError(err).Error("error calculating the local path on filesystem")
http.Error(w, "error opening the file on filesystem", http.StatusInternalServerError)
return
}

// save file to the filesystem
dst, err := os.Create(fullPath)
filePath, err := saveFileToFilesystem(baseDir, fileHeader.Filename, shasum[:], &buf)
if err != nil {
logrus.WithError(err).Error("error opening the file on filesystem")
http.Error(w, "error opening the file on filesystem", http.StatusInternalServerError)
return
}
defer dst.Close()

if _, err = io.Copy(dst, &buf); err != nil {
logrus.WithError(err).Error("error copying the file to filesystem")
http.Error(w, "error copying the file to filesystem", http.StatusInternalServerError)
return
}

// respond with file data
url, _ := url.Parse(domain) // checked on startup
Expand Down Expand Up @@ -169,3 +114,70 @@ func pubkeyIsApproved(pubkey string, pubkeys []string) bool {
}
return false
}

func getFileFromRequestBody(w http.ResponseWriter, r *http.Request) (multipart.File, *multipart.FileHeader, error) {
r.Body = http.MaxBytesReader(w, r.Body, MAX_UPLOAD_SIZE)
if err := r.ParseMultipartForm(MAX_UPLOAD_SIZE); err != nil {
return nil, nil, errors.New("file too big")
}

file, fileHeader, err := r.FormFile("file")
if err != nil {
logrus.WithError(err).Error("error getting file from request")
return nil, nil, errors.New("file not found in request")
}
defer file.Close()

// make buffer used to detect content type
buff := make([]byte, 512)
if _, err := file.Read(buff); err != nil {
logrus.WithError(err).Error("error reading 512 bytes from file in request")
return nil, nil, errors.New("unable to read file for mime detection")
}

filetype := http.DetectContentType(buff)
if filetype != "image/jpeg" && filetype != "image/png" {
return nil, nil, errors.New("invalid format. only jpeg and png are accepted")
}

// seek back to beginning to get whole file
if _, err := file.Seek(0, io.SeekStart); err != nil {
logrus.WithError(err).Error("error seeking to beging of file")
return nil, nil, errors.New("unable to process the file")
}

return file, fileHeader, nil
}

func saveFileToFilesystem(baseDir, filename string, shasum []byte, buf *bytes.Buffer) (string, error) {
directory := createAndGetDirectory(shasum)
fullDirectory := filepath.Join(baseDir, directory)
if err := os.MkdirAll(fullDirectory, os.ModePerm); err != nil {
logrus.WithError(err).Error("error creating the directory on filesystem")
return "", errors.New("error preparing the file")
}

// get name and paths to file
extension := filepath.Ext(filename)
name := fmt.Sprintf("%s%s", hex.EncodeToString(shasum), extension)
filePath := filepath.Join(directory, name)
fullPath, err := filepath.Abs(filepath.Join(fullDirectory, name))
if err != nil {
logrus.WithError(err).Error("error calculating the local path on filesystem")
return "", errors.New("error opening the file on filesystem")
}

dst, err := os.Create(fullPath)
if err != nil {
logrus.WithError(err).Error("error opening the file on filesystem")
return "", errors.New("error opening the file on filesystem")
}
defer dst.Close()

if _, err = io.Copy(dst, buf); err != nil {
logrus.WithError(err).Error("error copying the file to filesystem")
return "", errors.New("error copying the file to filesystem")
}

return filePath, nil
}

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