package autorest
// Copyright 2017 Microsoft Corporation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
import (
"crypto/tls"
"encoding/base64"
"fmt"
"net/http"
"net/url"
"strings"
"github.com/Azure/go-autorest/autorest/adal"
)
const (
bearerChallengeHeader = "Www-Authenticate"
bearer = "Bearer"
tenantID = "tenantID"
apiKeyAuthorizerHeader = "Ocp-Apim-Subscription-Key"
bingAPISdkHeader = "X-BingApis-SDK-Client"
golangBingAPISdkHeaderValue = "Go-SDK"
authorization = "Authorization"
basic = "Basic"
)
// Authorizer is the interface that provides a PrepareDecorator used to supply request
// authorization. Most often, the Authorizer decorator runs last so it has access to the full
// state of the formed HTTP request.
type Authorizer interface {
WithAuthorization() PrepareDecorator
}
// NullAuthorizer implements a default, "do nothing" Authorizer.
type NullAuthorizer struct{}
// WithAuthorization returns a PrepareDecorator that does nothing.
func (na NullAuthorizer) WithAuthorization() PrepareDecorator {
return WithNothing()
}
// APIKeyAuthorizer implements API Key authorization.
type APIKeyAuthorizer struct {
headers map[string]interface{}
queryParameters map[string]interface{}
}
// NewAPIKeyAuthorizerWithHeaders creates an ApiKeyAuthorizer with headers.
func NewAPIKeyAuthorizerWithHeaders(headers map[string]interface{}) *APIKeyAuthorizer {
return NewAPIKeyAuthorizer(headers, nil)
}
// NewAPIKeyAuthorizerWithQueryParameters creates an ApiKeyAuthorizer with query parameters.
func NewAPIKeyAuthorizerWithQueryParameters(queryParameters map[string]interface{}) *APIKeyAuthorizer {
return NewAPIKeyAuthorizer(nil, queryParameters)
}
// NewAPIKeyAuthorizer creates an ApiKeyAuthorizer with headers.
func NewAPIKeyAuthorizer(headers map[string]interface{}, queryParameters map[string]interface{}) *APIKeyAuthorizer {
return &APIKeyAuthorizer{headers: headers, queryParameters: queryParameters}
}
// WithAuthorization returns a PrepareDecorator that adds an HTTP headers and Query Parameters.
func (aka *APIKeyAuthorizer) WithAuthorization() PrepareDecorator {
return func(p Preparer) Preparer {
return DecoratePreparer(p, WithHeaders(aka.headers), WithQueryParameters(aka.queryParameters))
}
}
// CognitiveServicesAuthorizer implements authorization for Cognitive Services.
type CognitiveServicesAuthorizer struct {
subscriptionKey string
}
// NewCognitiveServicesAuthorizer is
func NewCognitiveServicesAuthorizer(subscriptionKey string) *CognitiveServicesAuthorizer {
return &CognitiveServicesAuthorizer{subscriptionKey: subscriptionKey}
}
// WithAuthorization is
func (csa *CognitiveServicesAuthorizer) WithAuthorization() PrepareDecorator {
headers := make(map[string]interface{})
headers[apiKeyAuthorizerHeader] = csa.subscriptionKey
headers[bingAPISdkHeader] = golangBingAPISdkHeaderValue
return NewAPIKeyAuthorizerWithHeaders(headers).WithAuthorization()
}
// BearerAuthorizer implements the bearer authorization
type BearerAuthorizer struct {
tokenProvider adal.OAuthTokenProvider
}
// NewBearerAuthorizer crates a BearerAuthorizer using the given token provider
func NewBearerAuthorizer(tp adal.OAuthTokenProvider) *BearerAuthorizer {
return &BearerAuthorizer{tokenProvider: tp}
}
// WithAuthorization returns a PrepareDecorator that adds an HTTP Authorization header whose
// value is "Bearer " followed by the token.
//
// By default, the token will be automatically refreshed through the Refresher interface.
func (ba *BearerAuthorizer) WithAuthorization() PrepareDecorator {
return func(p Preparer) Preparer {
return PreparerFunc(func(r *http.Request) (*http.Request, error) {
r, err := p.Prepare(r)
if err == nil {
// the ordering is important here, prefer RefresherWithContext if available
if refresher, ok := ba.tokenProvider.(adal.RefresherWithContext); ok {
err = refresher.EnsureFreshWithContext(r.Context())
} else if refresher, ok := ba.tokenProvider.(adal.Refresher); ok {
err = refresher.EnsureFresh()
}
if err != nil {
var resp *http.Response
if tokError, ok := err.(adal.TokenRefreshError); ok {
resp = tokError.Response()
}
return r, NewErrorWithError(err, "azure.BearerAuthorizer", "WithAuthorization", resp,
"Failed to refresh the Token for request to %s", r.URL)
}
return Prepare(r, WithHeader(headerAuthorization, fmt.Sprintf("Bearer %s", ba.tokenProvider.OAuthToken())))
}
return r, err
})
}
}
// BearerAuthorizerCallbackFunc is the authentication callback signature.
type BearerAuthorizerCallbackFunc func(tenantID, resource string) (*BearerAuthorizer, error)
// BearerAuthorizerCallback implements bearer authorization via a callback.
type BearerAuthorizerCallback struct {
sender Sender
callback BearerAuthorizerCallbackFunc
}
// NewBearerAuthorizerCallback creates a bearer authorization callback. The callback
// is invoked when the HTTP request is submitted.
func NewBearerAuthorizerCallback(s Sender, callback BearerAuthorizerCallbackFunc) *BearerAuthorizerCallback {
if s == nil {
s = sender(tls.RenegotiateNever)
}
return &BearerAuthorizerCallback{sender: s, callback: callback}
}
// WithAuthorization returns a PrepareDecorator that adds an HTTP Authorization header whose value
// is "Bearer " followed by the token. The BearerAuthorizer is obtained via a user-supplied callback.
//
// By default, the token will be automatically refreshed through the Refresher interface.
func (bacb *BearerAuthorizerCallback) WithAuthorization() PrepareDecorator {
return func(p Preparer) Preparer {
return PreparerFunc(func(r *http.Request) (*http.Request, error) {
r, err := p.Prepare(r)
if err == nil {
// make a copy of the request and remove the body as it's not
// required and avoids us having to create a copy of it.
rCopy := *r
removeRequestBody(&rCopy)
resp, err := bacb.sender.Do(&rCopy)
if err != nil {
return r, err
}
DrainResponseBody(resp)
if resp.StatusCode == 401 && hasBearerChallenge(resp.Header) {
bc, err := newBearerChallenge(resp.Header)
if err != nil {
return r, err
}
if bacb.callback != nil {
ba, err := bacb.callback(bc.values[tenantID], bc.values["resource"])
if err != nil {
return r, err
}
return Prepare(r, ba.WithAuthorization())
}
}
}
return r, err
})
}
}
// returns true if the HTTP response contains a bearer challenge
func hasBearerChallenge(header http.Header) bool {
authHeader := header.Get(bearerChallengeHeader)
if len(authHeader) == 0 || strings.Index(authHeader, bearer) < 0 {
return false
}
return true
}
type bearerChallenge struct {
values map[string]string
}
func newBearerChallenge(header http.Header) (bc bearerChallenge, err error) {
challenge := strings.TrimSpace(header.Get(bearerChallengeHeader))
trimmedChallenge := challenge[len(bearer)+1:]
// challenge is a set of key=value pairs that are comma delimited
pairs := strings.Split(trimmedChallenge, ",")
if len(pairs) < 1 {
err = fmt.Errorf("challenge '%s' contains no pairs", challenge)
return bc, err
}
bc.values = make(map[string]string)
for i := range pairs {
trimmedPair := strings.TrimSpace(pairs[i])
pair := strings.Split(trimmedPair, "=")
if len(pair) == 2 {
// remove the enclosing quotes
key := strings.Trim(pair[0], "\"")
value := strings.Trim(pair[1], "\"")
switch key {
case "authorization", "authorization_uri":
// strip the tenant ID from the authorization URL
asURL, err := url.Parse(value)
if err != nil {
return bc, err
}
bc.values[tenantID] = asURL.Path[1:]
default:
bc.values[key] = value
}
}
}
return bc, err
}
// EventGridKeyAuthorizer implements authorization for event grid using key authentication.
type EventGridKeyAuthorizer struct {
topicKey string
}
// NewEventGridKeyAuthorizer creates a new EventGridKeyAuthorizer
// with the specified topic key.
func NewEventGridKeyAuthorizer(topicKey string) EventGridKeyAuthorizer {
return EventGridKeyAuthorizer{topicKey: topicKey}
}
// WithAuthorization returns a PrepareDecorator that adds the aeg-sas-key authentication header.
func (egta EventGridKeyAuthorizer) WithAuthorization() PrepareDecorator {
headers := map[string]interface{}{
"aeg-sas-key": egta.topicKey,
}
return NewAPIKeyAuthorizerWithHeaders(headers).WithAuthorization()
}
// BasicAuthorizer implements basic HTTP authorization by adding the Authorization HTTP header
// with the value "Basic <TOKEN>" where <TOKEN> is a base64-encoded username:password tuple.
type BasicAuthorizer struct {
userName string
password string
}
// NewBasicAuthorizer creates a new BasicAuthorizer with the specified username and password.
func NewBasicAuthorizer(userName, password string) *BasicAuthorizer {
return &BasicAuthorizer{
userName: userName,
password: password,
}
}
// WithAuthorization returns a PrepareDecorator that adds an HTTP Authorization header whose
// value is "Basic " followed by the base64-encoded username:password tuple.
func (ba *BasicAuthorizer) WithAuthorization() PrepareDecorator {
headers := make(map[string]interface{})
headers[authorization] = basic + " " + base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%s:%s", ba.userName, ba.password)))
return NewAPIKeyAuthorizerWithHeaders(headers).WithAuthorization()
}
// MultiTenantServicePrincipalTokenAuthorizer provides authentication across tenants.
type MultiTenantServicePrincipalTokenAuthorizer interface {
WithAuthorization() PrepareDecorator
}
// NewMultiTenantServicePrincipalTokenAuthorizer crates a BearerAuthorizer using the given token provider
func NewMultiTenantServicePrincipalTokenAuthorizer(tp adal.MultitenantOAuthTokenProvider) MultiTenantServicePrincipalTokenAuthorizer {
return &multiTenantSPTAuthorizer{tp: tp}
}
type multiTenantSPTAuthorizer struct {
tp adal.MultitenantOAuthTokenProvider
}
// WithAuthorization returns a PrepareDecorator that adds an HTTP Authorization header using the
// primary token along with the auxiliary authorization header using the auxiliary tokens.
//
// By default, the token will be automatically refreshed through the Refresher interface.
func (mt multiTenantSPTAuthorizer) WithAuthorization() PrepareDecorator {
return func(p Preparer) Preparer {
return PreparerFunc(func(r *http.Request) (*http.Request, error) {
r, err := p.Prepare(r)
if err != nil {
return r, err
}
if refresher, ok := mt.tp.(adal.RefresherWithContext); ok {
err = refresher.EnsureFreshWithContext(r.Context())
if err != nil {
var resp *http.Response
if tokError, ok := err.(adal.TokenRefreshError); ok {
resp = tokError.Response()
}
return r, NewErrorWithError(err, "azure.multiTenantSPTAuthorizer", "WithAuthorization", resp,
"Failed to refresh one or more Tokens for request to %s", r.URL)
}
}
r, err = Prepare(r, WithHeader(headerAuthorization, fmt.Sprintf("Bearer %s", mt.tp.PrimaryOAuthToken())))
if err != nil {
return r, err
}
auxTokens := mt.tp.AuxiliaryOAuthTokens()
for i := range auxTokens {
auxTokens[i] = fmt.Sprintf("Bearer %s", auxTokens[i])
}
return Prepare(r, WithHeader(headerAuxAuthorization, strings.Join(auxTokens, "; ")))
})
}
}