Add KeyCredential and SASCredential types (Azure#21553)

* Add KeyCredential and SASCredential types

Includes supporting pipeline policies, config options, etc.

* add tests

* change Format func to Prefix string

* remove error return value from constructors

* remove error return for Update method

sdk/azcore/CHANGELOG.md

@@ -4,6 +4,11 @@
 
 ### Features Added
 
+* Added types `KeyCredential` and `SASCredential` to the `azcore` package.
+  * Includes their respective constructor functions.
+* Added types `KeyCredentialPolicy` and `SASCredentialPolicy` to the `azcore/runtime` package.
+  * Includes their respective constructor functions and options types.
+
 ### Breaking Changes
 
 ### Bugs Fixed

sdk/azcore/core.go

@@ -22,6 +22,24 @@ type AccessToken = exported.AccessToken
 // TokenCredential represents a credential capable of providing an OAuth token.
 type TokenCredential = exported.TokenCredential
 
+// KeyCredential contains an authentication key used to authenticate to an Azure service.
+type KeyCredential = exported.KeyCredential
+
+// NewKeyCredential creates a new instance of [KeyCredential] with the specified values.
+//   - key is the authentication key
+func NewKeyCredential(key string) *KeyCredential {
+	return exported.NewKeyCredential(key)
+}
+
+// SASCredential contains a shared access signature used to authenticate to an Azure service.
+type SASCredential = exported.SASCredential
+
+// NewSASCredential creates a new instance of [SASCredential] with the specified values.
+//   - sas is the shared access signature
+func NewSASCredential(sas string) *SASCredential {
+	return exported.NewSASCredential(sas)
+}
+
 // holds sentinel values used to send nulls
 var nullables map[reflect.Type]interface{} = map[reflect.Type]interface{}{}
 

sdk/azcore/core_test.go

@@ -221,3 +221,11 @@ func TestClientWithClientName(t *testing.T) {
 	require.NoError(t, err)
 	require.EqualValues(t, "az.namespace:Widget.Factory", attrString)
 }
+
+func TestNewKeyCredential(t *testing.T) {
+	require.NotNil(t, NewKeyCredential("foo"))
+}
+
+func TestNewSASCredential(t *testing.T) {
+	require.NotNil(t, NewSASCredential("foo"))
+}

sdk/azcore/internal/exported/exported.go

@@ -12,6 +12,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"sync/atomic"
 	"time"
 )
 
@@ -110,3 +111,65 @@ func DecodeByteArray(s string, v *[]byte, format Base64Encoding) error {
 		return fmt.Errorf("unrecognized byte array format: %d", format)
 	}
 }
+
+// KeyCredential contains an authentication key used to authenticate to an Azure service.
+// Exported as azcore.KeyCredential.
+type KeyCredential struct {
+	cred *keyCredential
+}
+
+// NewKeyCredential creates a new instance of [KeyCredential] with the specified values.
+//   - key is the authentication key
+func NewKeyCredential(key string) *KeyCredential {
+	return &KeyCredential{cred: newKeyCredential(key)}
+}
+
+// Update replaces the existing key with the specified value.
+func (k *KeyCredential) Update(key string) {
+	k.cred.Update(key)
+}
+
+// SASCredential contains a shared access signature used to authenticate to an Azure service.
+// Exported as azcore.SASCredential.
+type SASCredential struct {
+	cred *keyCredential
+}
+
+// NewSASCredential creates a new instance of [SASCredential] with the specified values.
+//   - sas is the shared access signature
+func NewSASCredential(sas string) *SASCredential {
+	return &SASCredential{cred: newKeyCredential(sas)}
+}
+
+// Update replaces the existing shared access signature with the specified value.
+func (k *SASCredential) Update(sas string) {
+	k.cred.Update(sas)
+}
+
+// KeyCredentialGet returns the key for cred.
+func KeyCredentialGet(cred *KeyCredential) string {
+	return cred.cred.Get()
+}
+
+// SASCredentialGet returns the shared access sig for cred.
+func SASCredentialGet(cred *SASCredential) string {
+	return cred.cred.Get()
+}
+
+type keyCredential struct {
+	key atomic.Value // string
+}
+
+func newKeyCredential(key string) *keyCredential {
+	keyCred := keyCredential{}
+	keyCred.key.Store(key)
+	return &keyCred
+}
+
+func (k *keyCredential) Get() string {
+	return k.key.Load().(string)
+}
+
+func (k *keyCredential) Update(key string) {
+	k.key.Store(key)
+}

sdk/azcore/internal/exported/exported_test.go

@@ -7,9 +7,12 @@
 package exported
 
 import (
+	"fmt"
 	"net/http"
 	"strings"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestNopCloser(t *testing.T) {
@@ -33,3 +36,41 @@ func TestHasStatusCode(t *testing.T) {
 		t.Fatal("unexpected failure")
 	}
 }
+
+func TestDecodeByteArray(t *testing.T) {
+	out := []byte{}
+	require.NoError(t, DecodeByteArray("", &out, Base64StdFormat))
+	require.Empty(t, out)
+	const (
+		stdEncoding = "VGVzdERlY29kZUJ5dGVBcnJheQ=="
+		urlEncoding = "VGVzdERlY29kZUJ5dGVBcnJheQ"
+		decoded     = "TestDecodeByteArray"
+	)
+	require.NoError(t, DecodeByteArray(stdEncoding, &out, Base64StdFormat))
+	require.EqualValues(t, decoded, string(out))
+	require.NoError(t, DecodeByteArray(urlEncoding, &out, Base64URLFormat))
+	require.EqualValues(t, decoded, string(out))
+	require.NoError(t, DecodeByteArray(fmt.Sprintf("\"%s\"", stdEncoding), &out, Base64StdFormat))
+	require.EqualValues(t, decoded, string(out))
+	require.Error(t, DecodeByteArray(stdEncoding, &out, 123))
+}
+
+func TestNewKeyCredential(t *testing.T) {
+	const val1 = "foo"
+	cred := NewKeyCredential(val1)
+	require.NotNil(t, cred)
+	require.EqualValues(t, val1, KeyCredentialGet(cred))
+	const val2 = "bar"
+	cred.Update(val2)
+	require.EqualValues(t, val2, KeyCredentialGet(cred))
+}
+
+func TestNewSASCredential(t *testing.T) {
+	const val1 = "foo"
+	cred := NewSASCredential(val1)
+	require.NotNil(t, cred)
+	require.EqualValues(t, val1, SASCredentialGet(cred))
+	const val2 = "bar"
+	cred.Update(val2)
+	require.EqualValues(t, val2, SASCredentialGet(cred))
+}

sdk/azcore/runtime/policy_key_credential.go

@@ -0,0 +1,49 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package runtime
+
+import (
+	"net/http"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/internal/exported"
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/policy"
+)
+
+// KeyCredentialPolicy authorizes requests with a [azcore.KeyCredential].
+type KeyCredentialPolicy struct {
+	cred   *exported.KeyCredential
+	header string
+	prefix string
+}
+
+// KeyCredentialPolicyOptions contains the optional values configuring [KeyCredentialPolicy].
+type KeyCredentialPolicyOptions struct {
+	// Prefix is used if the key requires a prefix before it's inserted into the HTTP request.
+	Prefix string
+}
+
+// NewKeyCredentialPolicy creates a new instance of [KeyCredentialPolicy].
+//   - cred is the [azcore.KeyCredential] used to authenticate with the service
+//   - header is the name of the HTTP request header in which the key is placed
+//   - options contains optional configuration, pass nil to accept the default values
+func NewKeyCredentialPolicy(cred *exported.KeyCredential, header string, options *KeyCredentialPolicyOptions) *KeyCredentialPolicy {
+	if options == nil {
+		options = &KeyCredentialPolicyOptions{}
+	}
+	return &KeyCredentialPolicy{
+		cred:   cred,
+		header: header,
+		prefix: options.Prefix,
+	}
+}
+
+// Do implementes the Do method on the [policy.Polilcy] interface.
+func (k *KeyCredentialPolicy) Do(req *policy.Request) (*http.Response, error) {
+	val := exported.KeyCredentialGet(k.cred)
+	if k.prefix != "" {
+		val = k.prefix + val
+	}
+	req.Raw().Header.Add(k.header, val)
+	return req.Next()
+}

sdk/azcore/runtime/policy_key_credential_test.go

@@ -0,0 +1,50 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package runtime
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/internal/exported"
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/internal/shared"
+	"github.com/stretchr/testify/require"
+)
+
+func TestKeyCredentialPolicy(t *testing.T) {
+	const key = "foo"
+	cred := exported.NewKeyCredential(key)
+
+	const headerName = "fake-auth"
+	policy := NewKeyCredentialPolicy(cred, headerName, nil)
+	require.NotNil(t, policy)
+
+	pl := exported.NewPipeline(shared.TransportFunc(func(req *http.Request) (*http.Response, error) {
+		require.EqualValues(t, key, req.Header.Get(headerName))
+		return &http.Response{}, nil
+	}), policy)
+
+	req, err := NewRequest(context.Background(), http.MethodGet, "http://contoso.com")
+	require.NoError(t, err)
+
+	_, err = pl.Do(req)
+	require.NoError(t, err)
+
+	policy = NewKeyCredentialPolicy(cred, headerName, &KeyCredentialPolicyOptions{
+		Prefix: "Prefix: ",
+	})
+	require.NotNil(t, policy)
+
+	pl = exported.NewPipeline(shared.TransportFunc(func(req *http.Request) (*http.Response, error) {
+		require.EqualValues(t, "Prefix: "+key, req.Header.Get(headerName))
+		return &http.Response{}, nil
+	}), policy)
+
+	req, err = NewRequest(context.Background(), http.MethodGet, "http://contoso.com")
+	require.NoError(t, err)
+
+	_, err = pl.Do(req)
+	require.NoError(t, err)
+}

sdk/azcore/runtime/policy_sas_credential.go

@@ -0,0 +1,39 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package runtime
+
+import (
+	"net/http"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/internal/exported"
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/policy"
+)
+
+// SASCredentialPolicy authorizes requests with a [azcore.SASCredential].
+type SASCredentialPolicy struct {
+	cred   *exported.SASCredential
+	header string
+}
+
+// SASCredentialPolicyOptions contains the optional values configuring [SASCredentialPolicy].
+type SASCredentialPolicyOptions struct {
+	// placeholder for future optional values
+}
+
+// NewSASCredentialPolicy creates a new instance of [SASCredentialPolicy].
+//   - cred is the [azcore.SASCredential] used to authenticate with the service
+//   - header is the name of the HTTP request header in which the shared access signature is placed
+//   - options contains optional configuration, pass nil to accept the default values
+func NewSASCredentialPolicy(cred *exported.SASCredential, header string, options *SASCredentialPolicyOptions) *SASCredentialPolicy {
+	return &SASCredentialPolicy{
+		cred:   cred,
+		header: header,
+	}
+}
+
+// Do implementes the Do method on the [policy.Polilcy] interface.
+func (k *SASCredentialPolicy) Do(req *policy.Request) (*http.Response, error) {
+	req.Raw().Header.Add(k.header, exported.SASCredentialGet(k.cred))
+	return req.Next()
+}

sdk/azcore/runtime/polilcy_sas_credential_test.go

@@ -0,0 +1,34 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package runtime
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/internal/exported"
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/internal/shared"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSASCredentialPolicy(t *testing.T) {
+	const key = "foo"
+	cred := exported.NewSASCredential(key)
+
+	const headerName = "fake-auth"
+	policy := NewSASCredentialPolicy(cred, headerName, nil)
+	require.NotNil(t, policy)
+
+	pl := exported.NewPipeline(shared.TransportFunc(func(req *http.Request) (*http.Response, error) {
+		require.EqualValues(t, key, req.Header.Get(headerName))
+		return &http.Response{}, nil
+	}), policy)
+
+	req, err := NewRequest(context.Background(), http.MethodGet, "http://contoso.com")
+	require.NoError(t, err)
+
+	_, err = pl.Do(req)
+	require.NoError(t, err)
+}