Update sso credential provider to support token provider

aws/credentials/ssocreds/provider.go

@@ -54,6 +54,19 @@ type Provider struct {
 
 	// The URL that points to the organization's AWS Single Sign-On (AWS SSO) user portal.
 	StartURL string
+
+	// The filepath the cached token will be retrieved from. If unset Provider will
+	// use the startURL to determine the filepath at.
+	//
+	//    ~/.aws/sso/cache/<sha1-hex-encoded-startURL>.json
+	//
+	// If custom cached token filepath is used, the Provider's startUrl
+	// parameter will be ignored.
+	CachedTokenFilepath string
+
+	// Used by the SSOCredentialProvider if a token configuration
+	// profile is used in the shared config
+	SSOTokenProvider *SSOTokenProvider
 }
 
 // NewCredentials returns a new AWS Single Sign-On (AWS SSO) credential provider. The ConfigProvider is expected to be configured
@@ -88,13 +101,31 @@ func (p *Provider) Retrieve() (credentials.Value, error) {
 // RetrieveWithContext retrieves temporary AWS credentials from the configured Amazon Single Sign-On (AWS SSO) user portal
 // by exchanging the accessToken present in ~/.aws/sso/cache.
 func (p *Provider) RetrieveWithContext(ctx credentials.Context) (credentials.Value, error) {
-	tokenFile, err := loadTokenFile(p.StartURL)
-	if err != nil {
-		return credentials.Value{}, err
+	var accessToken *string
+	if p.SSOTokenProvider != nil {
+		token, err := p.SSOTokenProvider.RetrieveBearerToken(ctx)
+		if err != nil {
+			return credentials.Value{}, err
+		}
+		accessToken = &token.Value
+	} else {
+		if p.CachedTokenFilepath == "" {
+			cachedTokenFilePath, err := getCachedFilePath(p.StartURL)
+			if err != nil {
+				return credentials.Value{}, err
+			}
+			p.CachedTokenFilepath = cachedTokenFilePath
+		}
+
+		tokenFile, err := loadTokenFile(p.CachedTokenFilepath)
+		if err != nil {
+			return credentials.Value{}, err
+		}
+		accessToken = &tokenFile.AccessToken
 	}
 
 	output, err := p.Client.GetRoleCredentialsWithContext(ctx, &sso.GetRoleCredentialsInput{
-		AccessToken: &tokenFile.AccessToken,
+		AccessToken: accessToken,
 		AccountId:   &p.AccountID,
 		RoleName:    &p.RoleName,
 	})
@@ -113,13 +144,13 @@ func (p *Provider) RetrieveWithContext(ctx credentials.Context) (credentials.Val
 	}, nil
 }
 
-func getCacheFileName(url string) (string, error) {
+func getCachedFilePath(startUrl string) (string, error) {
 	hash := sha1.New()
-	_, err := hash.Write([]byte(url))
+	_, err := hash.Write([]byte(startUrl))
 	if err != nil {
 		return "", err
 	}
-	return strings.ToLower(hex.EncodeToString(hash.Sum(nil))) + ".json", nil
+	return filepath.Join(defaultCacheLocation(), strings.ToLower(hex.EncodeToString(hash.Sum(nil)))+".json"), nil
 }
 
 type token struct {
@@ -133,13 +164,8 @@ func (t token) Expired() bool {
 	return nowTime().Round(0).After(time.Time(t.ExpiresAt))
 }
 
-func loadTokenFile(startURL string) (t token, err error) {
-	key, err := getCacheFileName(startURL)
-	if err != nil {
-		return token{}, awserr.New(ErrCodeSSOProviderInvalidToken, invalidTokenMessage, err)
-	}
-
-	fileBytes, err := ioutil.ReadFile(filepath.Join(defaultCacheLocation(), key))
+func loadTokenFile(cachedTokenPath string) (t token, err error) {
+	fileBytes, err := ioutil.ReadFile(cachedTokenPath)
 	if err != nil {
 		return token{}, awserr.New(ErrCodeSSOProviderInvalidToken, invalidTokenMessage, err)
 	}

aws/credentials/ssocreds/provider_test.go

@@ -5,6 +5,7 @@ package ssocreds
 
 import (
 	"fmt"
+	"path/filepath"
 	"reflect"
 	"testing"
 	"time"
@@ -88,11 +89,12 @@ func TestProvider(t *testing.T) {
 	defer restoreTime()
 
 	cases := map[string]struct {
-		Client    mockClient
-		AccountID string
-		Region    string
-		RoleName  string
-		StartURL  string
+		Client              mockClient
+		AccountID           string
+		Region              string
+		RoleName            string
+		StartURL            string
+		CachedTokenFilePath string
 
 		ExpectedErr         bool
 		ExpectedCredentials credentials.Value
@@ -131,6 +133,35 @@ func TestProvider(t *testing.T) {
 			},
 			ExpectedExpire: time.Date(2021, 01, 20, 21, 22, 23, 0.123e9, time.UTC),
 		},
+		"custom cached token file": {
+			Client: mockClient{
+				ExpectedAccountID:   "012345678901",
+				ExpectedRoleName:    "TestRole",
+				ExpectedAccessToken: "ZhbHVldGhpcyBpcyBub3QgYSByZWFsIH",
+				Response: func(mock mockClient) (*sso.GetRoleCredentialsOutput, error) {
+					return &sso.GetRoleCredentialsOutput{
+						RoleCredentials: &sso.RoleCredentials{
+							AccessKeyId:     aws.String("AccessKey"),
+							SecretAccessKey: aws.String("SecretKey"),
+							SessionToken:    aws.String("SessionToken"),
+							Expiration:      aws.Int64(1611177743123),
+						},
+					}, nil
+				},
+			},
+			CachedTokenFilePath: filepath.Join("testdata", "custom_cached_token.json"),
+			AccountID:           "012345678901",
+			Region:              "us-west-2",
+			RoleName:            "TestRole",
+			StartURL:            "ignored value",
+			ExpectedCredentials: credentials.Value{
+				AccessKeyID:     "AccessKey",
+				SecretAccessKey: "SecretKey",
+				SessionToken:    "SessionToken",
+				ProviderName:    ProviderName,
+			},
+			ExpectedExpire: time.Date(2021, 01, 20, 21, 22, 23, 0.123e9, time.UTC),
+		},
 		"expired access token": {
 			StartURL:    "https://expired",
 			ExpectedErr: true,
@@ -158,10 +189,11 @@ func TestProvider(t *testing.T) {
 			tt.Client.t = t
 
 			provider := &Provider{
-				Client:    tt.Client,
-				AccountID: tt.AccountID,
-				RoleName:  tt.RoleName,
-				StartURL:  tt.StartURL,
+				Client:              tt.Client,
+				AccountID:           tt.AccountID,
+				RoleName:            tt.RoleName,
+				StartURL:            tt.StartURL,
+				CachedTokenFilepath: tt.CachedTokenFilePath,
 			}
 
 			provider.Expiry.CurrentTime = nowTime

aws/credentials/ssocreds/testdata/custom_cached_token.json

@@ -0,0 +1,4 @@
+{
+  "accessToken": "ZhbHVldGhpcyBpcyBub3QgYSByZWFsIH",
+  "expiresAt": "2021-01-19T23:00:00Z"
+}

aws/session/credentials.go

@@ -14,6 +14,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/defaults"
 	"github.com/aws/aws-sdk-go/aws/request"
 	"github.com/aws/aws-sdk-go/internal/shareddefaults"
+	"github.com/aws/aws-sdk-go/service/ssooidc"
 	"github.com/aws/aws-sdk-go/service/sts"
 )
 
@@ -173,8 +174,25 @@ func resolveSSOCredentials(cfg *aws.Config, sharedCfg sharedConfig, handlers req
 		return nil, err
 	}
 
+	var optFns []func(provider *ssocreds.Provider)
 	cfgCopy := cfg.Copy()
-	cfgCopy.Region = &sharedCfg.SSORegion
+
+	if sharedCfg.SSOSession != nil {
+		cfgCopy.Region = &sharedCfg.SSOSession.SSORegion
+		cachedPath, err := ssocreds.StandardCachedTokenFilepath(sharedCfg.SSOSession.Name)
+		if err != nil {
+			return nil, err
+		}
+		mySession := Must(NewSession())
+		oidcClient := ssooidc.New(mySession, cfgCopy)
+		tokenProvider := ssocreds.NewSSOTokenProvider(oidcClient, cachedPath)
+		optFns = append(optFns, func(p *ssocreds.Provider) {
+			p.SSOTokenProvider = tokenProvider
+			p.CachedTokenFilepath = cachedPath
+		})
+	} else {
+		cfgCopy.Region = &sharedCfg.SSORegion
+	}
 
 	return ssocreds.NewCredentials(
 		&Session{
@@ -184,6 +202,7 @@ func resolveSSOCredentials(cfg *aws.Config, sharedCfg sharedConfig, handlers req
 		sharedCfg.SSOAccountID,
 		sharedCfg.SSORoleName,
 		sharedCfg.SSOStartURL,
+		optFns...,
 	), nil
 }