google/internal/externalaccount: Added check for aws region and security credential environment variables before aws metadata call

Adds check for aws values in environment variables before the metadata server is called to prevent unnecessary off box calls. See https://github.com/googleapis/google-auth-library-java/pull/1100 for same change in java library.

Change-Id: Ie86a899be88c38d3fcbbe377f9bf30a7a66530c0
GitHub-Last-Rev: bcab69572cb0dca4c7c6426203d4232e6e89d8db
GitHub-Pull-Request: golang/oauth2#612
Reviewed-on: https://go-review.googlesource.com/c/oauth2/+/453715
Reviewed-by: Leo Siracusa <leosiracusa@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cody Oss <codyoss@google.com>
Auto-Submit: Cody Oss <codyoss@google.com>
Reviewed-by: Cody Oss <codyoss@google.com>
This commit is contained in:
aeitzman 2022-11-30 16:37:52 +00:00 committed by Gopher Robot
parent ec4a9b2ff2
commit 510acbce1f
2 changed files with 277 additions and 49 deletions

View File

@ -62,6 +62,13 @@ const (
// The AWS authorization header name for the auto-generated date.
awsDateHeader = "x-amz-date"
// Supported AWS configuration environment variables.
awsAccessKeyId = "AWS_ACCESS_KEY_ID"
awsDefaultRegion = "AWS_DEFAULT_REGION"
awsRegion = "AWS_REGION"
awsSecretAccessKey = "AWS_SECRET_ACCESS_KEY"
awsSessionToken = "AWS_SESSION_TOKEN"
awsTimeFormatLong = "20060102T150405Z"
awsTimeFormatShort = "20060102"
)
@ -317,16 +324,33 @@ func (cs awsCredentialSource) doRequest(req *http.Request) (*http.Response, erro
return cs.client.Do(req.WithContext(cs.ctx))
}
func canRetrieveRegionFromEnvironment() bool {
// The AWS region can be provided through AWS_REGION or AWS_DEFAULT_REGION. Only one is
// required.
return getenv(awsRegion) != "" || getenv(awsDefaultRegion) != ""
}
func canRetrieveSecurityCredentialFromEnvironment() bool {
// Check if both AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY are available.
return getenv(awsAccessKeyId) != "" && getenv(awsSecretAccessKey) != ""
}
func shouldUseMetadataServer() bool {
return !canRetrieveRegionFromEnvironment() || !canRetrieveSecurityCredentialFromEnvironment()
}
func (cs awsCredentialSource) subjectToken() (string, error) {
if cs.requestSigner == nil {
awsSessionToken, err := cs.getAWSSessionToken()
if err != nil {
return "", err
}
headers := make(map[string]string)
if awsSessionToken != "" {
headers[awsIMDSv2SessionTokenHeader] = awsSessionToken
if shouldUseMetadataServer() {
awsSessionToken, err := cs.getAWSSessionToken()
if err != nil {
return "", err
}
if awsSessionToken != "" {
headers[awsIMDSv2SessionTokenHeader] = awsSessionToken
}
}
awsSecurityCredentials, err := cs.getSecurityCredentials(headers)
@ -432,11 +456,11 @@ func (cs *awsCredentialSource) getAWSSessionToken() (string, error) {
}
func (cs *awsCredentialSource) getRegion(headers map[string]string) (string, error) {
if envAwsRegion := getenv("AWS_REGION"); envAwsRegion != "" {
return envAwsRegion, nil
}
if envAwsRegion := getenv("AWS_DEFAULT_REGION"); envAwsRegion != "" {
return envAwsRegion, nil
if canRetrieveRegionFromEnvironment() {
if envAwsRegion := getenv(awsRegion); envAwsRegion != "" {
return envAwsRegion, nil
}
return getenv("AWS_DEFAULT_REGION"), nil
}
if cs.RegionURL == "" {
@ -477,14 +501,12 @@ func (cs *awsCredentialSource) getRegion(headers map[string]string) (string, err
}
func (cs *awsCredentialSource) getSecurityCredentials(headers map[string]string) (result awsSecurityCredentials, err error) {
if accessKeyID := getenv("AWS_ACCESS_KEY_ID"); accessKeyID != "" {
if secretAccessKey := getenv("AWS_SECRET_ACCESS_KEY"); secretAccessKey != "" {
return awsSecurityCredentials{
AccessKeyID: accessKeyID,
SecretAccessKey: secretAccessKey,
SecurityToken: getenv("AWS_SESSION_TOKEN"),
}, nil
}
if canRetrieveSecurityCredentialFromEnvironment() {
return awsSecurityCredentials{
AccessKeyID: getenv(awsAccessKeyId),
SecretAccessKey: getenv(awsSecretAccessKey),
SecurityToken: getenv(awsSessionToken),
}, nil
}
roleName, err := cs.getMetadataRoleName(headers)

View File

@ -474,6 +474,38 @@ func createDefaultAwsTestServer() *testAwsServer {
)
}
func createDefaultAwsTestServerWithImdsv2(t *testing.T) *testAwsServer {
validateSessionTokenHeaders := func(r *http.Request) {
if r.URL.Path == "/latest/api/token" {
headerValue := r.Header.Get(awsIMDSv2SessionTtlHeader)
if headerValue != awsIMDSv2SessionTtl {
t.Errorf("%q = \n%q\n want \n%q", awsIMDSv2SessionTtlHeader, headerValue, awsIMDSv2SessionTtl)
}
} else {
headerValue := r.Header.Get(awsIMDSv2SessionTokenHeader)
if headerValue != "sessiontoken" {
t.Errorf("%q = \n%q\n want \n%q", awsIMDSv2SessionTokenHeader, headerValue, "sessiontoken")
}
}
}
return createAwsTestServer(
"/latest/meta-data/iam/security-credentials",
"/latest/meta-data/placement/availability-zone",
"https://sts.{region}.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15",
"/latest/api/token",
"gcp-aws-role",
"us-east-2b",
map[string]string{
"SecretAccessKey": secretAccessKey,
"AccessKeyId": accessKeyID,
"Token": securityToken,
},
"sessiontoken",
validateSessionTokenHeaders,
)
}
func (server *testAwsServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
switch p := r.URL.Path; p {
case server.url:
@ -597,35 +629,7 @@ func TestAWSCredential_BasicRequest(t *testing.T) {
}
func TestAWSCredential_IMDSv2(t *testing.T) {
validateSessionTokenHeaders := func(r *http.Request) {
if r.URL.Path == "/latest/api/token" {
headerValue := r.Header.Get(awsIMDSv2SessionTtlHeader)
if headerValue != awsIMDSv2SessionTtl {
t.Errorf("%q = \n%q\n want \n%q", awsIMDSv2SessionTtlHeader, headerValue, awsIMDSv2SessionTtl)
}
} else {
headerValue := r.Header.Get(awsIMDSv2SessionTokenHeader)
if headerValue != "sessiontoken" {
t.Errorf("%q = \n%q\n want \n%q", awsIMDSv2SessionTokenHeader, headerValue, "sessiontoken")
}
}
}
server := createAwsTestServer(
"/latest/meta-data/iam/security-credentials",
"/latest/meta-data/placement/availability-zone",
"https://sts.{region}.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15",
"/latest/api/token",
"gcp-aws-role",
"us-east-2b",
map[string]string{
"SecretAccessKey": secretAccessKey,
"AccessKeyId": accessKeyID,
"Token": securityToken,
},
"sessiontoken",
validateSessionTokenHeaders,
)
server := createDefaultAwsTestServerWithImdsv2(t)
ts := httptest.NewServer(server)
tsURL, err := neturl.Parse(ts.URL)
if err != nil {
@ -1152,6 +1156,208 @@ func TestAWSCredential_RequestWithBadFinalCredentialURL(t *testing.T) {
}
}
func TestAWSCredential_ShouldNotCallMetadataEndpointWhenCredsAreInEnv(t *testing.T) {
server := createDefaultAwsTestServer()
ts := httptest.NewServer(server)
tsURL, err := neturl.Parse(ts.URL)
if err != nil {
t.Fatalf("couldn't parse httptest servername")
}
metadataTs := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Error("Metadata server should not have been called.")
}))
tfc := testFileConfig
tfc.CredentialSource = server.getCredentialSource(ts.URL)
tfc.CredentialSource.IMDSv2SessionTokenURL = metadataTs.URL
oldGetenv := getenv
oldNow := now
oldValidHostnames := validHostnames
defer func() {
getenv = oldGetenv
now = oldNow
validHostnames = oldValidHostnames
}()
getenv = setEnvironment(map[string]string{
"AWS_ACCESS_KEY_ID": "AKIDEXAMPLE",
"AWS_SECRET_ACCESS_KEY": "wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY",
"AWS_REGION": "us-west-1",
})
now = setTime(defaultTime)
validHostnames = []string{tsURL.Hostname()}
base, err := tfc.parse(context.Background())
if err != nil {
t.Fatalf("parse() failed %v", err)
}
out, err := base.subjectToken()
if err != nil {
t.Fatalf("retrieveSubjectToken() failed: %v", err)
}
expected := getExpectedSubjectToken(
"https://sts.us-west-1.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15",
"us-west-1",
"AKIDEXAMPLE",
"wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY",
"",
)
if got, want := out, expected; !reflect.DeepEqual(got, want) {
t.Errorf("subjectToken = \n%q\n want \n%q", got, want)
}
}
func TestAWSCredential_ShouldCallMetadataEndpointWhenNoRegion(t *testing.T) {
server := createDefaultAwsTestServerWithImdsv2(t)
ts := httptest.NewServer(server)
tsURL, err := neturl.Parse(ts.URL)
if err != nil {
t.Fatalf("couldn't parse httptest servername")
}
tfc := testFileConfig
tfc.CredentialSource = server.getCredentialSource(ts.URL)
oldGetenv := getenv
oldNow := now
oldValidHostnames := validHostnames
defer func() {
getenv = oldGetenv
now = oldNow
validHostnames = oldValidHostnames
}()
getenv = setEnvironment(map[string]string{
"AWS_ACCESS_KEY_ID": accessKeyID,
"AWS_SECRET_ACCESS_KEY": secretAccessKey,
})
now = setTime(defaultTime)
validHostnames = []string{tsURL.Hostname()}
base, err := tfc.parse(context.Background())
if err != nil {
t.Fatalf("parse() failed %v", err)
}
out, err := base.subjectToken()
if err != nil {
t.Fatalf("retrieveSubjectToken() failed: %v", err)
}
expected := getExpectedSubjectToken(
"https://sts.us-east-2.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15",
"us-east-2",
accessKeyID,
secretAccessKey,
"",
)
if got, want := out, expected; !reflect.DeepEqual(got, want) {
t.Errorf("subjectToken = \n%q\n want \n%q", got, want)
}
}
func TestAWSCredential_ShouldCallMetadataEndpointWhenNoAccessKey(t *testing.T) {
server := createDefaultAwsTestServerWithImdsv2(t)
ts := httptest.NewServer(server)
tsURL, err := neturl.Parse(ts.URL)
if err != nil {
t.Fatalf("couldn't parse httptest servername")
}
tfc := testFileConfig
tfc.CredentialSource = server.getCredentialSource(ts.URL)
oldGetenv := getenv
oldNow := now
oldValidHostnames := validHostnames
defer func() {
getenv = oldGetenv
now = oldNow
validHostnames = oldValidHostnames
}()
getenv = setEnvironment(map[string]string{
"AWS_SECRET_ACCESS_KEY": "wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY",
"AWS_REGION": "us-west-1",
})
now = setTime(defaultTime)
validHostnames = []string{tsURL.Hostname()}
base, err := tfc.parse(context.Background())
if err != nil {
t.Fatalf("parse() failed %v", err)
}
out, err := base.subjectToken()
if err != nil {
t.Fatalf("retrieveSubjectToken() failed: %v", err)
}
expected := getExpectedSubjectToken(
"https://sts.us-west-1.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15",
"us-west-1",
accessKeyID,
secretAccessKey,
securityToken,
)
if got, want := out, expected; !reflect.DeepEqual(got, want) {
t.Errorf("subjectToken = \n%q\n want \n%q", got, want)
}
}
func TestAWSCredential_ShouldCallMetadataEndpointWhenNoSecretAccessKey(t *testing.T) {
server := createDefaultAwsTestServerWithImdsv2(t)
ts := httptest.NewServer(server)
tsURL, err := neturl.Parse(ts.URL)
if err != nil {
t.Fatalf("couldn't parse httptest servername")
}
tfc := testFileConfig
tfc.CredentialSource = server.getCredentialSource(ts.URL)
oldGetenv := getenv
oldNow := now
oldValidHostnames := validHostnames
defer func() {
getenv = oldGetenv
now = oldNow
validHostnames = oldValidHostnames
}()
getenv = setEnvironment(map[string]string{
"AWS_ACCESS_KEY_ID": "AKIDEXAMPLE",
"AWS_REGION": "us-west-1",
})
now = setTime(defaultTime)
validHostnames = []string{tsURL.Hostname()}
base, err := tfc.parse(context.Background())
if err != nil {
t.Fatalf("parse() failed %v", err)
}
out, err := base.subjectToken()
if err != nil {
t.Fatalf("retrieveSubjectToken() failed: %v", err)
}
expected := getExpectedSubjectToken(
"https://sts.us-west-1.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15",
"us-west-1",
accessKeyID,
secretAccessKey,
securityToken,
)
if got, want := out, expected; !reflect.DeepEqual(got, want) {
t.Errorf("subjectToken = \n%q\n want \n%q", got, want)
}
}
func TestAWSCredential_Validations(t *testing.T) {
var metadataServerValidityTests = []struct {
name string