Add basic authorization (#369)

* Add basic authorization

* Add basic authorization

* update CHANGELOG and version, small refactor

* update comments

* refactor to accept username and password

CHANGELOG.md

@@ -1,5 +1,11 @@
 # CHANGELOG
 
+## v11.6.0
+
+### New Features
+
+- Added type `autorest.BasicAuthorizer` to support Basic authentication.
+
 ## v11.5.2
 
 ### Bug Fixes

autorest/authorization.go

@@ -15,6 +15,7 @@ package autorest
 //  limitations under the License.
 
 import (
+	"encoding/base64"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -31,6 +32,8 @@ const (
 	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
@@ -258,3 +261,27 @@ func (egta EventGridKeyAuthorizer) WithAuthorization() PrepareDecorator {
 	}
 	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()
+}

autorest/authorization_test.go

@@ -228,3 +228,25 @@ func TestCognitivesServicesAuthorization(t *testing.T) {
 		t.Fatalf("azure: CognitiveServicesAuthorizer#WithAuthorization failed to set %s header", apiKeyAuthorizerHeader)
 	}
 }
+
+func TestBasicAuthorization(t *testing.T) {
+	ba := NewBasicAuthorizer("Aladdin", "open sesame")
+	req, err := Prepare(mocks.NewRequest(), ba.WithAuthorization())
+
+	if err != nil {
+		t.Fatalf("BasicAuthorizer#WithAuthorization returned an error (%v)", err)
+	} else if req.Header.Get(http.CanonicalHeaderKey(authorization)) != basic+" QWxhZGRpbjpvcGVuIHNlc2FtZQ==" {
+		t.Fatalf("BasicAuthorizer#WithAuthorization failed to set %s header", authorization)
+	}
+}
+
+func TestBasicAuthorizationPasswordOnly(t *testing.T) {
+	ba := NewBasicAuthorizer("", "dummyKey")
+	req, err := Prepare(mocks.NewRequest(), ba.WithAuthorization())
+
+	if err != nil {
+		t.Fatalf("BasicAuthorizer#WithAuthorization returned an error (%v)", err)
+	} else if req.Header.Get(http.CanonicalHeaderKey(authorization)) != basic+" OmR1bW15S2V5" {
+		t.Fatalf("BasicAuthorizer#WithAuthorization failed to set %s header", authorization)
+	}
+}

autorest/version.go

@@ -19,7 +19,7 @@ import (
 	"runtime"
 )
 
-const number = "v11.5.2"
+const number = "v11.6.0"
 
 var (
 	userAgent = fmt.Sprintf("Go/%s (%s-%s) go-autorest/%s",