apiserver/pkg/apis/apiserver/validation/validation.go

827 lines
33 KiB
Go

/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package validation
import (
"errors"
"fmt"
"net/url"
"os"
"path/filepath"
"strings"
"time"
celgo "github.com/google/cel-go/cel"
"github.com/google/cel-go/common/operators"
exprpb "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
v1 "k8s.io/api/authorization/v1"
"k8s.io/api/authorization/v1beta1"
"k8s.io/apimachinery/pkg/util/sets"
utilvalidation "k8s.io/apimachinery/pkg/util/validation"
"k8s.io/apimachinery/pkg/util/validation/field"
api "k8s.io/apiserver/pkg/apis/apiserver"
authenticationcel "k8s.io/apiserver/pkg/authentication/cel"
authorizationcel "k8s.io/apiserver/pkg/authorization/cel"
"k8s.io/apiserver/pkg/cel"
"k8s.io/apiserver/pkg/cel/environment"
"k8s.io/apiserver/pkg/features"
utilfeature "k8s.io/apiserver/pkg/util/feature"
"k8s.io/client-go/util/cert"
)
// ValidateAuthenticationConfiguration validates a given AuthenticationConfiguration.
func ValidateAuthenticationConfiguration(c *api.AuthenticationConfiguration, disallowedIssuers []string) field.ErrorList {
root := field.NewPath("jwt")
var allErrs field.ErrorList
// We allow 0 authenticators in the authentication configuration.
// This allows us to support scenarios where the API server is initially set up without
// any authenticators and then authenticators are added later via dynamic config.
if len(c.JWT) > 64 {
allErrs = append(allErrs, field.TooMany(root, len(c.JWT), 64))
return allErrs
}
seenIssuers := sets.New[string]()
seenDiscoveryURLs := sets.New[string]()
for i, a := range c.JWT {
fldPath := root.Index(i)
_, errs := validateJWTAuthenticator(a, fldPath, sets.New(disallowedIssuers...), utilfeature.DefaultFeatureGate.Enabled(features.StructuredAuthenticationConfiguration))
allErrs = append(allErrs, errs...)
if seenIssuers.Has(a.Issuer.URL) {
allErrs = append(allErrs, field.Duplicate(fldPath.Child("issuer").Child("url"), a.Issuer.URL))
}
seenIssuers.Insert(a.Issuer.URL)
if len(a.Issuer.DiscoveryURL) > 0 {
if seenDiscoveryURLs.Has(a.Issuer.DiscoveryURL) {
allErrs = append(allErrs, field.Duplicate(fldPath.Child("issuer").Child("discoveryURL"), a.Issuer.DiscoveryURL))
}
seenDiscoveryURLs.Insert(a.Issuer.DiscoveryURL)
}
}
if c.Anonymous != nil {
if !utilfeature.DefaultFeatureGate.Enabled(features.AnonymousAuthConfigurableEndpoints) {
allErrs = append(allErrs, field.Forbidden(field.NewPath("anonymous"), "anonymous is not supported when AnonymousAuthConfigurableEnpoints feature gate is disabled"))
}
if !c.Anonymous.Enabled && len(c.Anonymous.Conditions) > 0 {
allErrs = append(allErrs, field.Invalid(field.NewPath("anonymous", "conditions"), c.Anonymous.Conditions, "enabled should be set to true when conditions are defined"))
}
}
return allErrs
}
// CompileAndValidateJWTAuthenticator validates a given JWTAuthenticator and returns a CELMapper with the compiled
// CEL expressions for claim mappings and validation rules.
// This is exported for use in oidc package.
func CompileAndValidateJWTAuthenticator(authenticator api.JWTAuthenticator, disallowedIssuers []string) (authenticationcel.CELMapper, field.ErrorList) {
return validateJWTAuthenticator(authenticator, nil, sets.New(disallowedIssuers...), utilfeature.DefaultFeatureGate.Enabled(features.StructuredAuthenticationConfiguration))
}
func validateJWTAuthenticator(authenticator api.JWTAuthenticator, fldPath *field.Path, disallowedIssuers sets.Set[string], structuredAuthnFeatureEnabled bool) (authenticationcel.CELMapper, field.ErrorList) {
var allErrs field.ErrorList
// strictCost is set to true which enables the strict cost for CEL validation.
compiler := authenticationcel.NewCompiler(environment.MustBaseEnvSet(environment.DefaultCompatibilityVersion(), true))
state := &validationState{}
allErrs = append(allErrs, validateIssuer(authenticator.Issuer, disallowedIssuers, fldPath.Child("issuer"), structuredAuthnFeatureEnabled)...)
allErrs = append(allErrs, validateClaimValidationRules(compiler, state, authenticator.ClaimValidationRules, fldPath.Child("claimValidationRules"), structuredAuthnFeatureEnabled)...)
allErrs = append(allErrs, validateClaimMappings(compiler, state, authenticator.ClaimMappings, fldPath.Child("claimMappings"), structuredAuthnFeatureEnabled)...)
allErrs = append(allErrs, validateUserValidationRules(compiler, state, authenticator.UserValidationRules, fldPath.Child("userValidationRules"), structuredAuthnFeatureEnabled)...)
return state.mapper, allErrs
}
type validationState struct {
mapper authenticationcel.CELMapper
usesEmailClaim bool
usesEmailVerifiedClaim bool
}
func validateIssuer(issuer api.Issuer, disallowedIssuers sets.Set[string], fldPath *field.Path, structuredAuthnFeatureEnabled bool) field.ErrorList {
var allErrs field.ErrorList
allErrs = append(allErrs, validateIssuerURL(issuer.URL, disallowedIssuers, fldPath.Child("url"))...)
allErrs = append(allErrs, validateIssuerDiscoveryURL(issuer.URL, issuer.DiscoveryURL, fldPath.Child("discoveryURL"), structuredAuthnFeatureEnabled)...)
allErrs = append(allErrs, validateAudiences(issuer.Audiences, issuer.AudienceMatchPolicy, fldPath.Child("audiences"), fldPath.Child("audienceMatchPolicy"), structuredAuthnFeatureEnabled)...)
allErrs = append(allErrs, validateCertificateAuthority(issuer.CertificateAuthority, fldPath.Child("certificateAuthority"))...)
return allErrs
}
func validateIssuerURL(issuerURL string, disallowedIssuers sets.Set[string], fldPath *field.Path) field.ErrorList {
if len(issuerURL) == 0 {
return field.ErrorList{field.Required(fldPath, "URL is required")}
}
return validateURL(issuerURL, disallowedIssuers, fldPath)
}
func validateIssuerDiscoveryURL(issuerURL, issuerDiscoveryURL string, fldPath *field.Path, structuredAuthnFeatureEnabled bool) field.ErrorList {
var allErrs field.ErrorList
if len(issuerDiscoveryURL) == 0 {
return nil
}
if !structuredAuthnFeatureEnabled {
allErrs = append(allErrs, field.Invalid(fldPath, issuerDiscoveryURL, "discoveryURL is not supported when StructuredAuthenticationConfiguration feature gate is disabled"))
}
if len(issuerURL) > 0 && strings.TrimRight(issuerURL, "/") == strings.TrimRight(issuerDiscoveryURL, "/") {
allErrs = append(allErrs, field.Invalid(fldPath, issuerDiscoveryURL, "discoveryURL must be different from URL"))
}
// issuerDiscoveryURL is not an issuer URL and does not need to validated against any set of disallowed issuers
allErrs = append(allErrs, validateURL(issuerDiscoveryURL, nil, fldPath)...)
return allErrs
}
func validateURL(issuerURL string, disallowedIssuers sets.Set[string], fldPath *field.Path) field.ErrorList {
var allErrs field.ErrorList
if disallowedIssuers.Has(issuerURL) {
allErrs = append(allErrs, field.Invalid(fldPath, issuerURL, fmt.Sprintf("URL must not overlap with disallowed issuers: %s", sets.List(disallowedIssuers))))
}
u, err := url.Parse(issuerURL)
if err != nil {
allErrs = append(allErrs, field.Invalid(fldPath, issuerURL, err.Error()))
return allErrs
}
if u.Scheme != "https" {
allErrs = append(allErrs, field.Invalid(fldPath, issuerURL, "URL scheme must be https"))
}
if u.User != nil {
allErrs = append(allErrs, field.Invalid(fldPath, issuerURL, "URL must not contain a username or password"))
}
if len(u.RawQuery) > 0 {
allErrs = append(allErrs, field.Invalid(fldPath, issuerURL, "URL must not contain a query"))
}
if len(u.Fragment) > 0 {
allErrs = append(allErrs, field.Invalid(fldPath, issuerURL, "URL must not contain a fragment"))
}
return allErrs
}
func validateAudiences(audiences []string, audienceMatchPolicy api.AudienceMatchPolicyType, fldPath, audienceMatchPolicyFldPath *field.Path, structuredAuthnFeatureEnabled bool) field.ErrorList {
var allErrs field.ErrorList
if len(audiences) == 0 {
allErrs = append(allErrs, field.Required(fldPath, fmt.Sprintf(atLeastOneRequiredErrFmt, fldPath)))
return allErrs
}
if len(audiences) > 1 && !structuredAuthnFeatureEnabled {
allErrs = append(allErrs, field.Invalid(fldPath, audiences, "multiple audiences are not supported when StructuredAuthenticationConfiguration feature gate is disabled"))
}
seenAudiences := sets.NewString()
for i, audience := range audiences {
fldPath := fldPath.Index(i)
if len(audience) == 0 {
allErrs = append(allErrs, field.Required(fldPath, "audience can't be empty"))
}
if seenAudiences.Has(audience) {
allErrs = append(allErrs, field.Duplicate(fldPath, audience))
}
seenAudiences.Insert(audience)
}
if len(audiences) > 1 && audienceMatchPolicy != api.AudienceMatchPolicyMatchAny {
allErrs = append(allErrs, field.Invalid(audienceMatchPolicyFldPath, audienceMatchPolicy, "audienceMatchPolicy must be MatchAny for multiple audiences"))
}
if len(audiences) == 1 && (len(audienceMatchPolicy) > 0 && audienceMatchPolicy != api.AudienceMatchPolicyMatchAny) {
allErrs = append(allErrs, field.Invalid(audienceMatchPolicyFldPath, audienceMatchPolicy, "audienceMatchPolicy must be empty or MatchAny for single audience"))
}
return allErrs
}
func validateCertificateAuthority(certificateAuthority string, fldPath *field.Path) field.ErrorList {
var allErrs field.ErrorList
if len(certificateAuthority) == 0 {
return allErrs
}
_, err := cert.NewPoolFromBytes([]byte(certificateAuthority))
if err != nil {
allErrs = append(allErrs, field.Invalid(fldPath, "<omitted>", err.Error()))
}
return allErrs
}
func validateClaimValidationRules(compiler authenticationcel.Compiler, state *validationState, rules []api.ClaimValidationRule, fldPath *field.Path, structuredAuthnFeatureEnabled bool) field.ErrorList {
var allErrs field.ErrorList
seenClaims := sets.NewString()
seenExpressions := sets.NewString()
var compilationResults []authenticationcel.CompilationResult
for i, rule := range rules {
fldPath := fldPath.Index(i)
if len(rule.Expression) > 0 && !structuredAuthnFeatureEnabled {
allErrs = append(allErrs, field.Invalid(fldPath.Child("expression"), rule.Expression, "expression is not supported when StructuredAuthenticationConfiguration feature gate is disabled"))
}
switch {
case len(rule.Claim) > 0 && len(rule.Expression) > 0:
allErrs = append(allErrs, field.Invalid(fldPath, rule.Claim, "claim and expression can't both be set"))
case len(rule.Claim) == 0 && len(rule.Expression) == 0:
allErrs = append(allErrs, field.Required(fldPath, "claim or expression is required"))
case len(rule.Claim) > 0:
if len(rule.Message) > 0 {
allErrs = append(allErrs, field.Invalid(fldPath.Child("message"), rule.Message, "message can't be set when claim is set"))
}
if seenClaims.Has(rule.Claim) {
allErrs = append(allErrs, field.Duplicate(fldPath.Child("claim"), rule.Claim))
}
seenClaims.Insert(rule.Claim)
case len(rule.Expression) > 0:
if len(rule.RequiredValue) > 0 {
allErrs = append(allErrs, field.Invalid(fldPath.Child("requiredValue"), rule.RequiredValue, "requiredValue can't be set when expression is set"))
}
if seenExpressions.Has(rule.Expression) {
allErrs = append(allErrs, field.Duplicate(fldPath.Child("expression"), rule.Expression))
continue
}
seenExpressions.Insert(rule.Expression)
compilationResult, err := compileClaimsCELExpression(compiler, &authenticationcel.ClaimValidationCondition{
Expression: rule.Expression,
Message: rule.Message,
}, fldPath.Child("expression"))
if err != nil {
allErrs = append(allErrs, err)
continue
}
if compilationResult != nil {
compilationResults = append(compilationResults, *compilationResult)
}
}
}
if structuredAuthnFeatureEnabled && len(compilationResults) > 0 {
state.mapper.ClaimValidationRules = authenticationcel.NewClaimsMapper(compilationResults)
state.usesEmailVerifiedClaim = state.usesEmailVerifiedClaim || anyUsesEmailVerifiedClaim(compilationResults)
}
return allErrs
}
func validateClaimMappings(compiler authenticationcel.Compiler, state *validationState, m api.ClaimMappings, fldPath *field.Path, structuredAuthnFeatureEnabled bool) field.ErrorList {
var allErrs field.ErrorList
if !structuredAuthnFeatureEnabled {
if len(m.Username.Expression) > 0 {
allErrs = append(allErrs, field.Invalid(fldPath.Child("username").Child("expression"), m.Username.Expression, "expression is not supported when StructuredAuthenticationConfiguration feature gate is disabled"))
}
if len(m.Groups.Expression) > 0 {
allErrs = append(allErrs, field.Invalid(fldPath.Child("groups").Child("expression"), m.Groups.Expression, "expression is not supported when StructuredAuthenticationConfiguration feature gate is disabled"))
}
if len(m.UID.Claim) > 0 || len(m.UID.Expression) > 0 {
allErrs = append(allErrs, field.Invalid(fldPath.Child("uid"), "", "uid claim mapping is not supported when StructuredAuthenticationConfiguration feature gate is disabled"))
}
if len(m.Extra) > 0 {
allErrs = append(allErrs, field.Invalid(fldPath.Child("extra"), "", "extra claim mapping is not supported when StructuredAuthenticationConfiguration feature gate is disabled"))
}
}
compilationResult, err := validatePrefixClaimOrExpression(compiler, m.Username, fldPath.Child("username"), true)
if err != nil {
allErrs = append(allErrs, err...)
} else if compilationResult != nil && structuredAuthnFeatureEnabled {
state.usesEmailClaim = state.usesEmailClaim || usesEmailClaim(compilationResult.AST)
state.usesEmailVerifiedClaim = state.usesEmailVerifiedClaim || usesEmailVerifiedClaim(compilationResult.AST)
state.mapper.Username = authenticationcel.NewClaimsMapper([]authenticationcel.CompilationResult{*compilationResult})
}
compilationResult, err = validatePrefixClaimOrExpression(compiler, m.Groups, fldPath.Child("groups"), false)
if err != nil {
allErrs = append(allErrs, err...)
} else if compilationResult != nil && structuredAuthnFeatureEnabled {
state.mapper.Groups = authenticationcel.NewClaimsMapper([]authenticationcel.CompilationResult{*compilationResult})
}
switch {
case len(m.UID.Claim) > 0 && len(m.UID.Expression) > 0:
allErrs = append(allErrs, field.Invalid(fldPath.Child("uid"), "", "claim and expression can't both be set"))
case len(m.UID.Expression) > 0:
compilationResult, err := compileClaimsCELExpression(compiler, &authenticationcel.ClaimMappingExpression{
Expression: m.UID.Expression,
}, fldPath.Child("uid").Child("expression"))
if err != nil {
allErrs = append(allErrs, err)
} else if structuredAuthnFeatureEnabled && compilationResult != nil {
state.mapper.UID = authenticationcel.NewClaimsMapper([]authenticationcel.CompilationResult{*compilationResult})
}
}
var extraCompilationResults []authenticationcel.CompilationResult
seenExtraKeys := sets.NewString()
for i, mapping := range m.Extra {
fldPath := fldPath.Child("extra").Index(i)
// Key should be namespaced to the authenticator or authenticator/authorizer pair making use of them.
// For instance: "example.org/foo" instead of "foo".
// xref: https://github.com/kubernetes/kubernetes/blob/3825e206cb162a7ad7431a5bdf6a065ae8422cf7/staging/src/k8s.io/apiserver/pkg/authentication/user/user.go#L31-L41
// IsDomainPrefixedPath checks for non-empty key and that the key is prefixed with a domain name.
allErrs = append(allErrs, utilvalidation.IsDomainPrefixedPath(fldPath.Child("key"), mapping.Key)...)
if mapping.Key != strings.ToLower(mapping.Key) {
allErrs = append(allErrs, field.Invalid(fldPath.Child("key"), mapping.Key, "key must be lowercase"))
}
if isKubernetesDomainPrefix(mapping.Key) {
allErrs = append(allErrs, field.Invalid(fldPath.Child("key"), mapping.Key, "k8s.io, kubernetes.io and their subdomains are reserved for Kubernetes use"))
}
if seenExtraKeys.Has(mapping.Key) {
allErrs = append(allErrs, field.Duplicate(fldPath.Child("key"), mapping.Key))
continue
}
seenExtraKeys.Insert(mapping.Key)
if len(mapping.ValueExpression) == 0 {
allErrs = append(allErrs, field.Required(fldPath.Child("valueExpression"), "valueExpression is required"))
continue
}
compilationResult, err := compileClaimsCELExpression(compiler, &authenticationcel.ExtraMappingExpression{
Key: mapping.Key,
Expression: mapping.ValueExpression,
}, fldPath.Child("valueExpression"))
if err != nil {
allErrs = append(allErrs, err)
continue
}
if compilationResult != nil {
extraCompilationResults = append(extraCompilationResults, *compilationResult)
}
}
if structuredAuthnFeatureEnabled && len(extraCompilationResults) > 0 {
state.mapper.Extra = authenticationcel.NewClaimsMapper(extraCompilationResults)
state.usesEmailVerifiedClaim = state.usesEmailVerifiedClaim || anyUsesEmailVerifiedClaim(extraCompilationResults)
}
if structuredAuthnFeatureEnabled && state.usesEmailClaim && !state.usesEmailVerifiedClaim {
allErrs = append(allErrs, field.Invalid(fldPath.Child("username", "expression"), m.Username.Expression,
"claims.email_verified must be used in claimMappings.username.expression or claimMappings.extra[*].valueExpression or claimValidationRules[*].expression when claims.email is used in claimMappings.username.expression"))
}
return allErrs
}
func isKubernetesDomainPrefix(key string) bool {
domainPrefix := getDomainPrefix(key)
if domainPrefix == "kubernetes.io" || strings.HasSuffix(domainPrefix, ".kubernetes.io") {
return true
}
if domainPrefix == "k8s.io" || strings.HasSuffix(domainPrefix, ".k8s.io") {
return true
}
return false
}
func getDomainPrefix(key string) string {
if parts := strings.SplitN(key, "/", 2); len(parts) == 2 {
return parts[0]
}
return ""
}
func usesEmailClaim(ast *celgo.Ast) bool {
return hasSelectExp(ast.Expr(), "claims", "email")
}
func anyUsesEmailVerifiedClaim(results []authenticationcel.CompilationResult) bool {
for _, result := range results {
if usesEmailVerifiedClaim(result.AST) {
return true
}
}
return false
}
func usesEmailVerifiedClaim(ast *celgo.Ast) bool {
return hasSelectExp(ast.Expr(), "claims", "email_verified")
}
func hasSelectExp(exp *exprpb.Expr, operand, field string) bool {
if exp == nil {
return false
}
switch e := exp.ExprKind.(type) {
case *exprpb.Expr_ConstExpr,
*exprpb.Expr_IdentExpr:
return false
case *exprpb.Expr_SelectExpr:
s := e.SelectExpr
if s == nil {
return false
}
if isIdentOperand(s.Operand, operand) && s.Field == field {
return true
}
return hasSelectExp(s.Operand, operand, field)
case *exprpb.Expr_CallExpr:
c := e.CallExpr
if c == nil {
return false
}
if c.Target == nil && c.Function == operators.OptSelect && len(c.Args) == 2 &&
isIdentOperand(c.Args[0], operand) && isConstField(c.Args[1], field) {
return true
}
for _, arg := range c.Args {
if hasSelectExp(arg, operand, field) {
return true
}
}
return hasSelectExp(c.Target, operand, field)
case *exprpb.Expr_ListExpr:
l := e.ListExpr
if l == nil {
return false
}
for _, element := range l.Elements {
if hasSelectExp(element, operand, field) {
return true
}
}
return false
case *exprpb.Expr_StructExpr:
s := e.StructExpr
if s == nil {
return false
}
for _, entry := range s.Entries {
if hasSelectExp(entry.GetMapKey(), operand, field) {
return true
}
if hasSelectExp(entry.Value, operand, field) {
return true
}
}
return false
case *exprpb.Expr_ComprehensionExpr:
c := e.ComprehensionExpr
if c == nil {
return false
}
return hasSelectExp(c.IterRange, operand, field) ||
hasSelectExp(c.AccuInit, operand, field) ||
hasSelectExp(c.LoopCondition, operand, field) ||
hasSelectExp(c.LoopStep, operand, field) ||
hasSelectExp(c.Result, operand, field)
default:
return false
}
}
func isIdentOperand(exp *exprpb.Expr, operand string) bool {
if len(operand) == 0 {
return false // sanity check against default values
}
id := exp.GetIdentExpr() // does not panic even if exp is nil
return id != nil && id.Name == operand
}
func isConstField(exp *exprpb.Expr, field string) bool {
if len(field) == 0 {
return false // sanity check against default values
}
c := exp.GetConstExpr() // does not panic even if exp is nil
return c != nil && c.GetStringValue() == field // does not panic even if c is not a string
}
func validatePrefixClaimOrExpression(compiler authenticationcel.Compiler, mapping api.PrefixedClaimOrExpression, fldPath *field.Path, claimOrExpressionRequired bool) (*authenticationcel.CompilationResult, field.ErrorList) {
var allErrs field.ErrorList
var compilationResult *authenticationcel.CompilationResult
switch {
case len(mapping.Expression) > 0 && len(mapping.Claim) > 0:
allErrs = append(allErrs, field.Invalid(fldPath, "", "claim and expression can't both be set"))
case len(mapping.Expression) == 0 && len(mapping.Claim) == 0 && claimOrExpressionRequired:
allErrs = append(allErrs, field.Required(fldPath, "claim or expression is required"))
case len(mapping.Expression) > 0:
var err *field.Error
if mapping.Prefix != nil {
allErrs = append(allErrs, field.Invalid(fldPath.Child("prefix"), *mapping.Prefix, "prefix can't be set when expression is set"))
}
compilationResult, err = compileClaimsCELExpression(compiler, &authenticationcel.ClaimMappingExpression{
Expression: mapping.Expression,
}, fldPath.Child("expression"))
if err != nil {
allErrs = append(allErrs, err)
}
case len(mapping.Claim) > 0:
if mapping.Prefix == nil {
allErrs = append(allErrs, field.Required(fldPath.Child("prefix"), "prefix is required when claim is set. It can be set to an empty string to disable prefixing"))
}
}
return compilationResult, allErrs
}
func validateUserValidationRules(compiler authenticationcel.Compiler, state *validationState, rules []api.UserValidationRule, fldPath *field.Path, structuredAuthnFeatureEnabled bool) field.ErrorList {
var allErrs field.ErrorList
var compilationResults []authenticationcel.CompilationResult
if len(rules) > 0 && !structuredAuthnFeatureEnabled {
allErrs = append(allErrs, field.Invalid(fldPath, "", "user validation rules are not supported when StructuredAuthenticationConfiguration feature gate is disabled"))
}
seenExpressions := sets.NewString()
for i, rule := range rules {
fldPath := fldPath.Index(i)
if len(rule.Expression) == 0 {
allErrs = append(allErrs, field.Required(fldPath.Child("expression"), "expression is required"))
continue
}
if seenExpressions.Has(rule.Expression) {
allErrs = append(allErrs, field.Duplicate(fldPath.Child("expression"), rule.Expression))
continue
}
seenExpressions.Insert(rule.Expression)
compilationResult, err := compileUserCELExpression(compiler, &authenticationcel.UserValidationCondition{
Expression: rule.Expression,
Message: rule.Message,
}, fldPath.Child("expression"))
if err != nil {
allErrs = append(allErrs, err)
continue
}
if compilationResult != nil {
compilationResults = append(compilationResults, *compilationResult)
}
}
if structuredAuthnFeatureEnabled && len(compilationResults) > 0 {
state.mapper.UserValidationRules = authenticationcel.NewUserMapper(compilationResults)
}
return allErrs
}
func compileClaimsCELExpression(compiler authenticationcel.Compiler, expression authenticationcel.ExpressionAccessor, fldPath *field.Path) (*authenticationcel.CompilationResult, *field.Error) {
compilationResult, err := compiler.CompileClaimsExpression(expression)
if err != nil {
return nil, convertCELErrorToValidationError(fldPath, expression.GetExpression(), err)
}
return &compilationResult, nil
}
func compileUserCELExpression(compiler authenticationcel.Compiler, expression authenticationcel.ExpressionAccessor, fldPath *field.Path) (*authenticationcel.CompilationResult, *field.Error) {
compilationResult, err := compiler.CompileUserExpression(expression)
if err != nil {
return nil, convertCELErrorToValidationError(fldPath, expression.GetExpression(), err)
}
return &compilationResult, nil
}
// ValidateAuthorizationConfiguration validates a given AuthorizationConfiguration.
func ValidateAuthorizationConfiguration(fldPath *field.Path, c *api.AuthorizationConfiguration, knownTypes sets.String, repeatableTypes sets.String) field.ErrorList {
allErrs := field.ErrorList{}
if len(c.Authorizers) == 0 {
allErrs = append(allErrs, field.Required(fldPath.Child("authorizers"), "at least one authorization mode must be defined"))
}
seenAuthorizerTypes := sets.NewString()
seenAuthorizerNames := sets.NewString()
for i, a := range c.Authorizers {
fldPath := fldPath.Child("authorizers").Index(i)
aType := string(a.Type)
if aType == "" {
allErrs = append(allErrs, field.Required(fldPath.Child("type"), ""))
continue
}
if !knownTypes.Has(aType) {
allErrs = append(allErrs, field.NotSupported(fldPath.Child("type"), aType, knownTypes.List()))
continue
}
if seenAuthorizerTypes.Has(aType) && !repeatableTypes.Has(aType) {
allErrs = append(allErrs, field.Duplicate(fldPath.Child("type"), aType))
continue
}
seenAuthorizerTypes.Insert(aType)
if len(a.Name) == 0 {
allErrs = append(allErrs, field.Required(fldPath.Child("name"), ""))
} else if seenAuthorizerNames.Has(a.Name) {
allErrs = append(allErrs, field.Duplicate(fldPath.Child("name"), a.Name))
} else if errs := utilvalidation.IsDNS1123Subdomain(a.Name); len(errs) != 0 {
allErrs = append(allErrs, field.Invalid(fldPath.Child("name"), a.Name, fmt.Sprintf("authorizer name is invalid: %s", strings.Join(errs, ", "))))
}
seenAuthorizerNames.Insert(a.Name)
switch a.Type {
case api.TypeWebhook:
if a.Webhook == nil {
allErrs = append(allErrs, field.Required(fldPath.Child("webhook"), "required when type=Webhook"))
continue
}
allErrs = append(allErrs, ValidateWebhookConfiguration(fldPath, a.Webhook)...)
default:
if a.Webhook != nil {
allErrs = append(allErrs, field.Invalid(fldPath.Child("webhook"), "non-null", "may only be specified when type=Webhook"))
}
}
}
return allErrs
}
func ValidateWebhookConfiguration(fldPath *field.Path, c *api.WebhookConfiguration) field.ErrorList {
allErrs := field.ErrorList{}
if c.Timeout.Duration == 0 {
allErrs = append(allErrs, field.Required(fldPath.Child("timeout"), ""))
} else if c.Timeout.Duration > 30*time.Second || c.Timeout.Duration < 0 {
allErrs = append(allErrs, field.Invalid(fldPath.Child("timeout"), c.Timeout.Duration.String(), "must be > 0s and <= 30s"))
}
if c.AuthorizedTTL.Duration == 0 {
allErrs = append(allErrs, field.Required(fldPath.Child("authorizedTTL"), ""))
} else if c.AuthorizedTTL.Duration < 0 {
allErrs = append(allErrs, field.Invalid(fldPath.Child("authorizedTTL"), c.AuthorizedTTL.Duration.String(), "must be > 0s"))
}
if c.UnauthorizedTTL.Duration == 0 {
allErrs = append(allErrs, field.Required(fldPath.Child("unauthorizedTTL"), ""))
} else if c.UnauthorizedTTL.Duration < 0 {
allErrs = append(allErrs, field.Invalid(fldPath.Child("unauthorizedTTL"), c.UnauthorizedTTL.Duration.String(), "must be > 0s"))
}
switch c.SubjectAccessReviewVersion {
case "":
allErrs = append(allErrs, field.Required(fldPath.Child("subjectAccessReviewVersion"), ""))
case "v1":
_ = &v1.SubjectAccessReview{}
case "v1beta1":
_ = &v1beta1.SubjectAccessReview{}
default:
allErrs = append(allErrs, field.NotSupported(fldPath.Child("subjectAccessReviewVersion"), c.SubjectAccessReviewVersion, []string{"v1", "v1beta1"}))
}
switch c.MatchConditionSubjectAccessReviewVersion {
case "":
if len(c.MatchConditions) > 0 {
allErrs = append(allErrs, field.Required(fldPath.Child("matchConditionSubjectAccessReviewVersion"), "required if match conditions are specified"))
}
case "v1":
_ = &v1.SubjectAccessReview{}
default:
allErrs = append(allErrs, field.NotSupported(fldPath.Child("matchConditionSubjectAccessReviewVersion"), c.MatchConditionSubjectAccessReviewVersion, []string{"v1"}))
}
switch c.FailurePolicy {
case "":
allErrs = append(allErrs, field.Required(fldPath.Child("failurePolicy"), ""))
case api.FailurePolicyNoOpinion, api.FailurePolicyDeny:
default:
allErrs = append(allErrs, field.NotSupported(fldPath.Child("failurePolicy"), c.FailurePolicy, []string{"NoOpinion", "Deny"}))
}
switch c.ConnectionInfo.Type {
case "":
allErrs = append(allErrs, field.Required(fldPath.Child("connectionInfo", "type"), ""))
case api.AuthorizationWebhookConnectionInfoTypeInCluster:
if c.ConnectionInfo.KubeConfigFile != nil {
allErrs = append(allErrs, field.Invalid(fldPath.Child("connectionInfo", "kubeConfigFile"), *c.ConnectionInfo.KubeConfigFile, "can only be set when type=KubeConfigFile"))
}
case api.AuthorizationWebhookConnectionInfoTypeKubeConfigFile:
if c.ConnectionInfo.KubeConfigFile == nil || *c.ConnectionInfo.KubeConfigFile == "" {
allErrs = append(allErrs, field.Required(fldPath.Child("connectionInfo", "kubeConfigFile"), ""))
} else if !filepath.IsAbs(*c.ConnectionInfo.KubeConfigFile) {
allErrs = append(allErrs, field.Invalid(fldPath.Child("connectionInfo", "kubeConfigFile"), *c.ConnectionInfo.KubeConfigFile, "must be an absolute path"))
} else if info, err := os.Stat(*c.ConnectionInfo.KubeConfigFile); err != nil {
allErrs = append(allErrs, field.Invalid(fldPath.Child("connectionInfo", "kubeConfigFile"), *c.ConnectionInfo.KubeConfigFile, fmt.Sprintf("error loading file: %v", err)))
} else if !info.Mode().IsRegular() {
allErrs = append(allErrs, field.Invalid(fldPath.Child("connectionInfo", "kubeConfigFile"), *c.ConnectionInfo.KubeConfigFile, "must be a regular file"))
}
default:
allErrs = append(allErrs, field.NotSupported(fldPath.Child("connectionInfo", "type"), c.ConnectionInfo, []string{api.AuthorizationWebhookConnectionInfoTypeInCluster, api.AuthorizationWebhookConnectionInfoTypeKubeConfigFile}))
}
_, errs := compileMatchConditions(c.MatchConditions, fldPath, utilfeature.DefaultFeatureGate.Enabled(features.StructuredAuthorizationConfiguration))
allErrs = append(allErrs, errs...)
return allErrs
}
// ValidateAndCompileMatchConditions validates a given webhook's matchConditions.
// This is exported for use in authz package.
func ValidateAndCompileMatchConditions(matchConditions []api.WebhookMatchCondition) (*authorizationcel.CELMatcher, field.ErrorList) {
return compileMatchConditions(matchConditions, nil, utilfeature.DefaultFeatureGate.Enabled(features.StructuredAuthorizationConfiguration))
}
func compileMatchConditions(matchConditions []api.WebhookMatchCondition, fldPath *field.Path, structuredAuthzFeatureEnabled bool) (*authorizationcel.CELMatcher, field.ErrorList) {
var allErrs field.ErrorList
// should fail when match conditions are used without feature enabled
if len(matchConditions) > 0 && !structuredAuthzFeatureEnabled {
allErrs = append(allErrs, field.Invalid(fldPath.Child("matchConditions"), "", "matchConditions are not supported when StructuredAuthorizationConfiguration feature gate is disabled"))
}
if len(matchConditions) > 64 {
allErrs = append(allErrs, field.TooMany(fldPath.Child("matchConditions"), len(matchConditions), 64))
return nil, allErrs
}
// strictCost is set to true which enables the strict cost for CEL validation.
compiler := authorizationcel.NewCompiler(environment.MustBaseEnvSet(environment.DefaultCompatibilityVersion(), true))
seenExpressions := sets.NewString()
var compilationResults []authorizationcel.CompilationResult
var usesFieldSelector, usesLabelSelector bool
for i, condition := range matchConditions {
fldPath := fldPath.Child("matchConditions").Index(i).Child("expression")
if len(strings.TrimSpace(condition.Expression)) == 0 {
allErrs = append(allErrs, field.Required(fldPath, ""))
continue
}
if seenExpressions.Has(condition.Expression) {
allErrs = append(allErrs, field.Duplicate(fldPath, condition.Expression))
continue
}
seenExpressions.Insert(condition.Expression)
compilationResult, err := compileMatchConditionsExpression(fldPath, compiler, condition.Expression)
if err != nil {
allErrs = append(allErrs, err)
continue
}
compilationResults = append(compilationResults, compilationResult)
usesFieldSelector = usesFieldSelector || compilationResult.UsesFieldSelector
usesLabelSelector = usesLabelSelector || compilationResult.UsesLabelSelector
}
if len(compilationResults) == 0 {
return nil, allErrs
}
return &authorizationcel.CELMatcher{
CompilationResults: compilationResults,
UsesFieldSelector: usesFieldSelector,
UsesLabelSelector: usesLabelSelector,
}, allErrs
}
func compileMatchConditionsExpression(fldPath *field.Path, compiler authorizationcel.Compiler, expression string) (authorizationcel.CompilationResult, *field.Error) {
authzExpression := &authorizationcel.SubjectAccessReviewMatchCondition{
Expression: expression,
}
compilationResult, err := compiler.CompileCELExpression(authzExpression)
if err != nil {
return compilationResult, convertCELErrorToValidationError(fldPath, authzExpression.GetExpression(), err)
}
return compilationResult, nil
}
func convertCELErrorToValidationError(fldPath *field.Path, expression string, err error) *field.Error {
var celErr *cel.Error
if errors.As(err, &celErr) {
switch celErr.Type {
case cel.ErrorTypeRequired:
return field.Required(fldPath, celErr.Detail)
case cel.ErrorTypeInvalid:
return field.Invalid(fldPath, expression, celErr.Detail)
default:
return field.InternalError(fldPath, celErr)
}
}
return field.InternalError(fldPath, fmt.Errorf("error is not cel error: %w", err))
}