Google bucket SignedUrls 403 - api

Question

I'm doing a simple rest API which does the following:
get base64 encoded image
decode it
stores it on on specific google bucket
Now, on the GET verb, my api returns a signed url targeting the bucket image.
I've coded a test that works:
initialization stuff
...
BeforeEach(func() {
mockStringGenerator.On("GenerateUuid").Return("image1")
// First store
image, _ = ioutil.ReadFile("test_data/DSCF6458.JPG")
encodedImage = b64.RawStdEncoding.EncodeToString(image)
fileName, storeError = storage.Store(ctx, encodedImage, "image/jpeg")
// Then get
uri, getError = storage.Get(ctx, fileName)
getResponse, _ = http.Get(uri)
// Finally delete
deleteError = storage.Delete(ctx, fileName)
})
// Only 1 test to avoid making too much connexion
It("should create, get and delete the image", func() {
// Store
Expect(storeError).To(BeNil())
Expect(fileName).To(Equal("image1.jpg"))
// Get
Expect(getError).To(BeNil())
Expect(getResponse.StatusCode).To(Equal(http.StatusOK))
b, _ := ioutil.ReadAll(getResponse.Body)
Expect(b).To(Equal(image))
// Delete
Expect(deleteError).To(BeNil())
})
But when I run the .exe and try to make ssome request with postman, I get a 403 error in the signed url:
<?xml version='1.0' encoding='UTF-8'?>
<Error>
<Code>AccessDenied</Code>
<Message>Access denied.</Message>
<Details>Anonymous caller does not have storage.objects.get access to teddycare-images/08d8c508-d97d-48d3-947b-a7f216f622db.jpg.</Details>
</Error>
Any ideas ? I really don't understand...
Save me guys
[EDIT] Here after the code I use to create signedUrl:
func (s *GoogleStorage) Get(ctx context.Context, fileName string) (string, error) {
url, err := storage.SignedURL(s.Config.BucketImagesName, fileName, &storage.SignedURLOptions{
GoogleAccessID: s.Config.BucketServiceAccountDetails.ClientEmail,
PrivateKey: []byte(s.Config.BucketServiceAccountDetails.PrivateKey),
Method: http.MethodGet,
Expires: time.Now().Add(time.Second * 180),
})
if err != nil {
return "", err
}
return url, nil
}

Answer 1

Ok, after I woke up, I found the answer.
It turns out that when the json is marshalized into string, all the special characters are encoded.
Example: & -> \u0026
So the url I tested in my UT had &, while the url returned by the api had \u0026, and google does not seem to have the same behaviour on both cases.
So the solution is to disable HTML escaping:
encoder := json.NewEncoder(w)
encoder.SetEscapeHTML(false)
return encoder.Encode(response)