1 package autorest
2 3 // Copyright 2017 Microsoft Corporation
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License");
6 // you may not use this file except in compliance with the License.
7 // You may obtain a copy of the License at
8 //
9 // http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 17 import (
18 "fmt"
19 "net/http"
20 "strings"
21 )
22 23 // SASTokenAuthorizer implements an authorization for SAS Token Authentication
24 // this can be used for interaction with Blob Storage Endpoints
25 type SASTokenAuthorizer struct {
26 sasToken string
27 }
28 29 // NewSASTokenAuthorizer creates a SASTokenAuthorizer using the given credentials
30 func NewSASTokenAuthorizer(sasToken string) (*SASTokenAuthorizer, error) {
31 if strings.TrimSpace(sasToken) == "" {
32 return nil, fmt.Errorf("sasToken cannot be empty")
33 }
34 35 token := sasToken
36 if strings.HasPrefix(sasToken, "?") {
37 token = strings.TrimPrefix(sasToken, "?")
38 }
39 40 return &SASTokenAuthorizer{
41 sasToken: token,
42 }, nil
43 }
44 45 // WithAuthorization returns a PrepareDecorator that adds a shared access signature token to the
46 // URI's query parameters. This can be used for the Blob, Queue, and File Services.
47 //
48 // See https://docs.microsoft.com/en-us/rest/api/storageservices/delegate-access-with-shared-access-signature
49 func (sas *SASTokenAuthorizer) WithAuthorization() PrepareDecorator {
50 return func(p Preparer) Preparer {
51 return PreparerFunc(func(r *http.Request) (*http.Request, error) {
52 r, err := p.Prepare(r)
53 if err != nil {
54 return r, err
55 }
56 57 if r.URL.RawQuery == "" {
58 r.URL.RawQuery = sas.sasToken
59 } else if !strings.Contains(r.URL.RawQuery, sas.sasToken) {
60 r.URL.RawQuery = fmt.Sprintf("%s&%s", r.URL.RawQuery, sas.sasToken)
61 }
62 63 return Prepare(r)
64 })
65 }
66 }
67