Merge pull request #125104 from enj/enj/i/sa_generics
serviceaccount: use generics to remove runtime type checks during validation
This commit is contained in:
		@@ -24,11 +24,11 @@ import (
 | 
			
		||||
 | 
			
		||||
	"github.com/google/uuid"
 | 
			
		||||
	"gopkg.in/square/go-jose.v2/jwt"
 | 
			
		||||
	"k8s.io/klog/v2"
 | 
			
		||||
 | 
			
		||||
	"k8s.io/apiserver/pkg/audit"
 | 
			
		||||
	apiserverserviceaccount "k8s.io/apiserver/pkg/authentication/serviceaccount"
 | 
			
		||||
	utilfeature "k8s.io/apiserver/pkg/util/feature"
 | 
			
		||||
	"k8s.io/klog/v2"
 | 
			
		||||
	"k8s.io/kubernetes/pkg/apis/core"
 | 
			
		||||
	"k8s.io/kubernetes/pkg/features"
 | 
			
		||||
)
 | 
			
		||||
@@ -128,7 +128,7 @@ func Claims(sa core.ServiceAccount, pod *core.Pod, secret *core.Secret, node *co
 | 
			
		||||
	return sc, pc, nil
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
func NewValidator(getter ServiceAccountTokenGetter) Validator {
 | 
			
		||||
func NewValidator(getter ServiceAccountTokenGetter) Validator[privateClaims] {
 | 
			
		||||
	return &validator{
 | 
			
		||||
		getter: getter,
 | 
			
		||||
	}
 | 
			
		||||
@@ -138,14 +138,9 @@ type validator struct {
 | 
			
		||||
	getter ServiceAccountTokenGetter
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
var _ = Validator(&validator{})
 | 
			
		||||
var _ = Validator[privateClaims](&validator{})
 | 
			
		||||
 | 
			
		||||
func (v *validator) Validate(ctx context.Context, _ string, public *jwt.Claims, privateObj interface{}) (*apiserverserviceaccount.ServiceAccountInfo, error) {
 | 
			
		||||
	private, ok := privateObj.(*privateClaims)
 | 
			
		||||
	if !ok {
 | 
			
		||||
		klog.Errorf("service account jwt validator expected private claim of type *privateClaims but got: %T", privateObj)
 | 
			
		||||
		return nil, errors.New("service account token claims could not be validated due to unexpected private claim")
 | 
			
		||||
	}
 | 
			
		||||
func (v *validator) Validate(ctx context.Context, _ string, public *jwt.Claims, private *privateClaims) (*apiserverserviceaccount.ServiceAccountInfo, error) {
 | 
			
		||||
	nowTime := now()
 | 
			
		||||
	err := public.Validate(jwt.Expected{
 | 
			
		||||
		Time: nowTime,
 | 
			
		||||
@@ -294,7 +289,3 @@ func (v *validator) Validate(ctx context.Context, _ string, public *jwt.Claims,
 | 
			
		||||
		CredentialID: apiserverserviceaccount.CredentialIDForJTI(jti),
 | 
			
		||||
	}, nil
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
func (v *validator) NewPrivateClaims() interface{} {
 | 
			
		||||
	return &privateClaims{}
 | 
			
		||||
}
 | 
			
		||||
 
 | 
			
		||||
@@ -225,12 +225,12 @@ func (j *jwtTokenGenerator) GenerateToken(claims *jwt.Claims, privateClaims inte
 | 
			
		||||
// JWTTokenAuthenticator authenticates tokens as JWT tokens produced by JWTTokenGenerator
 | 
			
		||||
// Token signatures are verified using each of the given public keys until one works (allowing key rotation)
 | 
			
		||||
// If lookup is true, the service account and secret referenced as claims inside the token are retrieved and verified with the provided ServiceAccountTokenGetter
 | 
			
		||||
func JWTTokenAuthenticator(issuers []string, keys []interface{}, implicitAuds authenticator.Audiences, validator Validator) authenticator.Token {
 | 
			
		||||
func JWTTokenAuthenticator[PrivateClaims any](issuers []string, keys []interface{}, implicitAuds authenticator.Audiences, validator Validator[PrivateClaims]) authenticator.Token {
 | 
			
		||||
	issuersMap := make(map[string]bool)
 | 
			
		||||
	for _, issuer := range issuers {
 | 
			
		||||
		issuersMap[issuer] = true
 | 
			
		||||
	}
 | 
			
		||||
	return &jwtTokenAuthenticator{
 | 
			
		||||
	return &jwtTokenAuthenticator[PrivateClaims]{
 | 
			
		||||
		issuers:      issuersMap,
 | 
			
		||||
		keys:         keys,
 | 
			
		||||
		implicitAuds: implicitAuds,
 | 
			
		||||
@@ -238,29 +238,25 @@ func JWTTokenAuthenticator(issuers []string, keys []interface{}, implicitAuds au
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
type jwtTokenAuthenticator struct {
 | 
			
		||||
type jwtTokenAuthenticator[PrivateClaims any] struct {
 | 
			
		||||
	issuers      map[string]bool
 | 
			
		||||
	keys         []interface{}
 | 
			
		||||
	validator    Validator
 | 
			
		||||
	validator    Validator[PrivateClaims]
 | 
			
		||||
	implicitAuds authenticator.Audiences
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
// Validator is called by the JWT token authenticator to apply domain specific
 | 
			
		||||
// validation to a token and extract user information.
 | 
			
		||||
type Validator interface {
 | 
			
		||||
// PrivateClaims is the struct that the authenticator should deserialize the JWT payload into, thus
 | 
			
		||||
// it should contain fields for any private claims that the Validator requires to validate the JWT.
 | 
			
		||||
type Validator[PrivateClaims any] interface {
 | 
			
		||||
	// Validate validates a token and returns user information or an error.
 | 
			
		||||
	// Validator can assume that the issuer and signature of a token are already
 | 
			
		||||
	// verified when this function is called.
 | 
			
		||||
	Validate(ctx context.Context, tokenData string, public *jwt.Claims, private interface{}) (*apiserverserviceaccount.ServiceAccountInfo, error)
 | 
			
		||||
	// NewPrivateClaims returns a struct that the authenticator should
 | 
			
		||||
	// deserialize the JWT payload into. The authenticator may then pass this
 | 
			
		||||
	// struct back to the Validator as the 'private' argument to a Validate()
 | 
			
		||||
	// call. This struct should contain fields for any private claims that the
 | 
			
		||||
	// Validator requires to validate the JWT.
 | 
			
		||||
	NewPrivateClaims() interface{}
 | 
			
		||||
	Validate(ctx context.Context, tokenData string, public *jwt.Claims, private *PrivateClaims) (*apiserverserviceaccount.ServiceAccountInfo, error)
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
func (j *jwtTokenAuthenticator) AuthenticateToken(ctx context.Context, tokenData string) (*authenticator.Response, bool, error) {
 | 
			
		||||
func (j *jwtTokenAuthenticator[PrivateClaims]) AuthenticateToken(ctx context.Context, tokenData string) (*authenticator.Response, bool, error) {
 | 
			
		||||
	if !j.hasCorrectIssuer(tokenData) {
 | 
			
		||||
		return nil, false, nil
 | 
			
		||||
	}
 | 
			
		||||
@@ -271,7 +267,7 @@ func (j *jwtTokenAuthenticator) AuthenticateToken(ctx context.Context, tokenData
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	public := &jwt.Claims{}
 | 
			
		||||
	private := j.validator.NewPrivateClaims()
 | 
			
		||||
	private := new(PrivateClaims)
 | 
			
		||||
 | 
			
		||||
	// TODO: Pick the key that has the same key ID as `tok`, if one exists.
 | 
			
		||||
	var (
 | 
			
		||||
@@ -334,7 +330,7 @@ func (j *jwtTokenAuthenticator) AuthenticateToken(ctx context.Context, tokenData
 | 
			
		||||
//
 | 
			
		||||
// Note: go-jose currently does not allow access to unverified JWS payloads.
 | 
			
		||||
// See https://github.com/square/go-jose/issues/169
 | 
			
		||||
func (j *jwtTokenAuthenticator) hasCorrectIssuer(tokenData string) bool {
 | 
			
		||||
func (j *jwtTokenAuthenticator[PrivateClaims]) hasCorrectIssuer(tokenData string) bool {
 | 
			
		||||
	if strings.HasPrefix(strings.TrimSpace(tokenData), "{") {
 | 
			
		||||
		return false
 | 
			
		||||
	}
 | 
			
		||||
 
 | 
			
		||||
@@ -25,6 +25,7 @@ import (
 | 
			
		||||
	"time"
 | 
			
		||||
 | 
			
		||||
	"gopkg.in/square/go-jose.v2/jwt"
 | 
			
		||||
 | 
			
		||||
	v1 "k8s.io/api/core/v1"
 | 
			
		||||
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 | 
			
		||||
	"k8s.io/apimachinery/pkg/types"
 | 
			
		||||
@@ -61,7 +62,7 @@ type legacyPrivateClaims struct {
 | 
			
		||||
	Namespace          string `json:"kubernetes.io/serviceaccount/namespace"`
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
func NewLegacyValidator(lookup bool, getter ServiceAccountTokenGetter, secretsWriter typedv1core.SecretsGetter) (Validator, error) {
 | 
			
		||||
func NewLegacyValidator(lookup bool, getter ServiceAccountTokenGetter, secretsWriter typedv1core.SecretsGetter) (Validator[legacyPrivateClaims], error) {
 | 
			
		||||
	if lookup && getter == nil {
 | 
			
		||||
		return nil, errors.New("ServiceAccountTokenGetter must be provided")
 | 
			
		||||
	}
 | 
			
		||||
@@ -81,15 +82,9 @@ type legacyValidator struct {
 | 
			
		||||
	secretsWriter typedv1core.SecretsGetter
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
var _ = Validator(&legacyValidator{})
 | 
			
		||||
 | 
			
		||||
func (v *legacyValidator) Validate(ctx context.Context, tokenData string, public *jwt.Claims, privateObj interface{}) (*apiserverserviceaccount.ServiceAccountInfo, error) {
 | 
			
		||||
	private, ok := privateObj.(*legacyPrivateClaims)
 | 
			
		||||
	if !ok {
 | 
			
		||||
		klog.Errorf("jwt validator expected private claim of type *legacyPrivateClaims but got: %T", privateObj)
 | 
			
		||||
		return nil, errors.New("Token could not be validated.")
 | 
			
		||||
	}
 | 
			
		||||
var _ = Validator[legacyPrivateClaims](&legacyValidator{})
 | 
			
		||||
 | 
			
		||||
func (v *legacyValidator) Validate(ctx context.Context, tokenData string, public *jwt.Claims, private *legacyPrivateClaims) (*apiserverserviceaccount.ServiceAccountInfo, error) {
 | 
			
		||||
	// Make sure the claims we need exist
 | 
			
		||||
	if len(public.Subject) == 0 {
 | 
			
		||||
		return nil, errors.New("sub claim is missing")
 | 
			
		||||
@@ -201,7 +196,3 @@ func (v *legacyValidator) patchSecretWithLastUsedDate(ctx context.Context, secre
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
func (v *legacyValidator) NewPrivateClaims() interface{} {
 | 
			
		||||
	return &legacyPrivateClaims{}
 | 
			
		||||
}
 | 
			
		||||
 
 | 
			
		||||
		Reference in New Issue
	
	Block a user