/
gcloud.go
347 lines (292 loc) · 10.5 KB
/
gcloud.go
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package gcpsecretmanager
import (
"context"
"crypto/sha1" //nolint: gosec // We use sha1 to hash trust domain names in 128 bytes to avoid secret label restrictions
"encoding/hex"
"encoding/json"
"fmt"
"sort"
"strings"
"sync"
"cloud.google.com/go/iam/apiv1/iampb"
"cloud.google.com/go/secretmanager/apiv1/secretmanagerpb"
"github.com/hashicorp/go-hclog"
"github.com/hashicorp/hcl"
"github.com/hashicorp/hcl/hcl/token"
svidstorev1 "github.com/spiffe/spire-plugin-sdk/proto/spire/plugin/agent/svidstore/v1"
configv1 "github.com/spiffe/spire-plugin-sdk/proto/spire/service/common/config/v1"
"github.com/spiffe/spire/pkg/agent/plugin/svidstore"
"github.com/spiffe/spire/pkg/common/catalog"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
)
const (
pluginName = "gcp_secretmanager"
)
func BuiltIn() catalog.BuiltIn {
return builtin(New())
}
func builtin(p *SecretManagerPlugin) catalog.BuiltIn {
return catalog.MakeBuiltIn(pluginName,
svidstorev1.SVIDStorePluginServer(p),
configv1.ConfigServiceServer(p),
)
}
func New() *SecretManagerPlugin {
return newPlugin(newSecretManagerClient)
}
func newPlugin(newSecretManagerClient func(context.Context, string) (secretManagerClient, error)) *SecretManagerPlugin {
p := &SecretManagerPlugin{}
p.hooks.newSecretManagerClient = newSecretManagerClient
return p
}
type Configuration struct {
ServiceAccountFile string `hcl:"service_account_file" json:"service_account_file"`
UnusedKeyPositions map[string][]token.Pos `hcl:",unusedKeyPositions" json:",omitempty"`
}
type SecretManagerPlugin struct {
svidstorev1.UnsafeSVIDStoreServer
configv1.UnsafeConfigServer
log hclog.Logger
mtx sync.RWMutex
secretManagerClient secretManagerClient
tdHash string
hooks struct {
newSecretManagerClient func(context.Context, string) (secretManagerClient, error)
}
}
func (p *SecretManagerPlugin) SetLogger(log hclog.Logger) {
p.log = log
}
// Configure configures the SecretManagerPlugin.
func (p *SecretManagerPlugin) Configure(ctx context.Context, req *configv1.ConfigureRequest) (*configv1.ConfigureResponse, error) {
// Parse HCL config payload into config struct
config := &Configuration{}
if err := hcl.Decode(config, req.HclConfiguration); err != nil {
return nil, status.Errorf(codes.InvalidArgument, "unable to decode configuration: %v", err)
}
if len(config.UnusedKeyPositions) != 0 {
var keys []string
for k := range config.UnusedKeyPositions {
keys = append(keys, k)
}
sort.Strings(keys)
return nil, status.Errorf(codes.InvalidArgument, "unknown configurations detected: %s", strings.Join(keys, ","))
}
secretMangerClient, err := p.hooks.newSecretManagerClient(ctx, config.ServiceAccountFile)
if err != nil {
return nil, status.Errorf(codes.Internal, "failed to create secretmanager client: %v", err)
}
// gcp secret manager does not allow ".", hash td as label
tdHash := sha1.Sum([]byte(req.CoreConfiguration.TrustDomain)) //nolint: gosec // We use sha1 to hash trust domain names in 128 bytes to avoid secret label restrictions
p.mtx.Lock()
defer p.mtx.Unlock()
p.secretManagerClient = secretMangerClient
p.tdHash = hex.EncodeToString(tdHash[:])
return &configv1.ConfigureResponse{}, nil
}
// PutX509SVID puts the specified X509-SVID in the configured Google Cloud Secrets Manager
func (p *SecretManagerPlugin) PutX509SVID(ctx context.Context, req *svidstorev1.PutX509SVIDRequest) (*svidstorev1.PutX509SVIDResponse, error) {
opt, err := optionsFromSecretData(req.Metadata)
if err != nil {
return nil, err
}
// Get secret, if it does not exist, a secret is created
secret, secretFound, err := getSecret(ctx, p.secretManagerClient, opt.secretName(), p.tdHash)
if err != nil {
return nil, err
}
// Secret not found, create it
if !secretFound {
secret, err = p.secretManagerClient.CreateSecret(ctx, &secretmanagerpb.CreateSecretRequest{
Parent: opt.parent(),
SecretId: opt.name,
Secret: &secretmanagerpb.Secret{
Replication: &secretmanagerpb.Replication{
Replication: &secretmanagerpb.Replication_Automatic_{
Automatic: &secretmanagerpb.Replication_Automatic{},
},
},
Labels: map[string]string{
"spire-svid": p.tdHash,
},
},
})
if err != nil {
return nil, status.Errorf(codes.Internal, "failed to create secret: %v", err)
}
p.log.With("secret_name", secret.Name).Debug("Secret created")
}
if opt.roleName != "" && opt.serviceAccount != "" {
ok, err := p.shouldSetPolicy(ctx, secret.Name, opt, secretFound)
if err != nil {
return nil, err
}
if ok {
if err := p.setIamPolicy(ctx, secret.Name, opt); err != nil {
return nil, err
}
}
}
secretData, err := svidstore.SecretFromProto(req)
if err != nil {
return nil, status.Errorf(codes.InvalidArgument, "failed to parse request: %v", err)
}
secretBinary, err := json.Marshal(secretData)
if err != nil {
return nil, status.Errorf(codes.Internal, "failed to marshal payload: %v", err)
}
resp, err := p.secretManagerClient.AddSecretVersion(ctx, &secretmanagerpb.AddSecretVersionRequest{
Parent: secret.Name,
Payload: &secretmanagerpb.SecretPayload{
Data: secretBinary,
},
})
if err != nil {
return nil, status.Errorf(codes.Internal, "failed to add secret version: %v", err)
}
p.log.With("state", resp.State).With("name", resp.Name).Debug("Secret payload updated")
return &svidstorev1.PutX509SVIDResponse{}, nil
}
// DeleteX509SVID deletes a secret in the configured Google Cloud Secret manager
func (p *SecretManagerPlugin) DeleteX509SVID(ctx context.Context, req *svidstorev1.DeleteX509SVIDRequest) (*svidstorev1.DeleteX509SVIDResponse, error) {
opt, err := optionsFromSecretData(req.Metadata)
if err != nil {
return nil, err
}
secret, ok, err := getSecret(ctx, p.secretManagerClient, opt.secretName(), p.tdHash)
if err != nil {
return nil, err
}
if !ok {
p.log.With("secret_name", opt.secretName()).Debug("Secret to delete not found")
return &svidstorev1.DeleteX509SVIDResponse{}, nil
}
if err := p.secretManagerClient.DeleteSecret(ctx, &secretmanagerpb.DeleteSecretRequest{
Name: secret.Name,
Etag: secret.Etag,
}); err != nil {
return nil, status.Errorf(codes.Internal, "failed to delete secret: %v", err)
}
p.log.With("secret_name", opt.secretName()).Debug("Secret deleted")
return &svidstorev1.DeleteX509SVIDResponse{}, nil
}
// getSecret gets secret from Google Cloud and validates if it has `spire-svid` label with hashed trust domain as value,
// nil if not found
func getSecret(ctx context.Context, client secretManagerClient, secretName string, tdHash string) (*secretmanagerpb.Secret, bool, error) {
secret, err := client.GetSecret(ctx, &secretmanagerpb.GetSecretRequest{
Name: secretName,
})
switch status.Code(err) {
case codes.OK:
// Verify that secret contains "spire-svid" label and it is enabled
if ok := validateLabels(secret.Labels, tdHash); !ok {
return nil, false, status.Error(codes.InvalidArgument, "secret is not managed by this SPIRE deployment")
}
case codes.NotFound:
return nil, false, nil
default:
return nil, false, status.Errorf(codes.Internal, "failed to get secret: %v", err)
}
return secret, true, nil
}
func (p *SecretManagerPlugin) shouldSetPolicy(ctx context.Context, secretName string, opt *secretOptions, secretFound bool) (bool, error) {
if !secretFound {
return true, nil
}
policy, err := p.secretManagerClient.GetIamPolicy(ctx, &iampb.GetIamPolicyRequest{
Resource: secretName,
})
if err != nil {
return false, status.Errorf(codes.Internal, "failed to get IAM policy: %v", err)
}
bindings := policy.Bindings
if len(bindings) != 1 {
return true, nil
}
binding := bindings[0]
switch {
case binding.Role != opt.roleName:
return true, nil
// Expecting a single Service account as member
case !expectedBindingMembers(binding.Members, opt.serviceAccount):
return true, nil
default:
return false, nil
}
}
func (p *SecretManagerPlugin) setIamPolicy(ctx context.Context, secretName string, opt *secretOptions) error {
// Create a policy without conditions and a single binding
resp, err := p.secretManagerClient.SetIamPolicy(ctx, &iampb.SetIamPolicyRequest{
Resource: opt.secretName(),
Policy: &iampb.Policy{
Bindings: []*iampb.Binding{
{
Role: opt.roleName,
Members: []string{opt.serviceAccount},
},
},
},
})
if err != nil {
return status.Errorf(codes.Internal, "failed to set IAM policy to secret: %v", err)
}
p.log.With("version", resp.Version).With("etag", string(resp.Etag)).With("secret_name", secretName).Debug("Secret IAM Policy updated")
return nil
}
type secretOptions struct {
projectID string
name string
roleName string
serviceAccount string
}
// parent gets parent in the format `projects/*`
func (s *secretOptions) parent() string {
return fmt.Sprintf("projects/%s", s.projectID)
}
// secretName gets secret name in format `projects/*/secrets/*`
func (s *secretOptions) secretName() string {
return fmt.Sprintf("projects/%s/secrets/%s", s.projectID, s.name)
}
func optionsFromSecretData(selectorData []string) (*secretOptions, error) {
data, err := svidstore.ParseMetadata(selectorData)
if err != nil {
return nil, status.Errorf(codes.InvalidArgument, "invalid metadata: %v", err)
}
// Getting secret name and project, both are required.
name, ok := data["name"]
if !ok {
return nil, status.Error(codes.InvalidArgument, "name is required")
}
projectID, ok := data["projectid"]
if !ok {
return nil, status.Error(codes.InvalidArgument, "projectid is required")
}
// example: "serviceAccount:project-id@appspot.gserviceaccount.com"
var serviceAccount string
if sa, ok := data["serviceaccount"]; ok {
serviceAccount = fmt.Sprintf("serviceAccount:%s", sa)
}
roleName := data["role"]
switch {
case serviceAccount != "" && roleName == "":
return nil, status.Error(codes.InvalidArgument, "role is required when service account is set")
case serviceAccount == "" && roleName != "":
return nil, status.Error(codes.InvalidArgument, "service account is required when role is set")
}
return &secretOptions{
name: name,
projectID: projectID,
roleName: roleName,
serviceAccount: serviceAccount,
}, nil
}
func validateLabels(labels map[string]string, tdHash string) bool {
spireLabel, ok := labels["spire-svid"]
return ok && spireLabel == tdHash
}
// expectedBindingMembers ensures that there is exactly one binding member, and
// that it matches the provided service account name
func expectedBindingMembers(bindingMembers []string, serviceAccount string) bool {
return len(bindingMembers) == 1 && bindingMembers[0] == serviceAccount
}