diff --git a/CHANGELOG.md b/CHANGELOG.md
index f30f4b2c..bd83ae08 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@
- [#2821](https://github.com/oauth2-proxy/oauth2-proxy/pull/2821) feat: add CF-Connecting-IP as supported real ip header (@ondrejsika)
- [#2620](https://github.com/oauth2-proxy/oauth2-proxy/pull/2620) fix: update code_verifier to use recommended method (@vishvananda)
- [#2392](https://github.com/oauth2-proxy/oauth2-proxy/pull/2392) chore: extend test cases for oidc provider and documentation regarding implicit setting of the groups scope when no scope was specified in the config (@jjlakis / @tuunit)
+- [#2902](https://github.com/oauth2-proxy/oauth2-proxy/pull/2902) feat(entra): add Workload Identity support for Entra ID (@jjlakis)
# V7.7.1
diff --git a/docs/docs/configuration/alpha_config.md b/docs/docs/configuration/alpha_config.md
index 55a1984b..0108810f 100644
--- a/docs/docs/configuration/alpha_config.md
+++ b/docs/docs/configuration/alpha_config.md
@@ -394,6 +394,7 @@ character.
| Field | Type | Description |
| ----- | ---- | ----------- |
| `allowedTenants` | _[]string_ | AllowedTenants is a list of allowed tenants. In case of multi-tenant apps, incoming tokens are
issued by different issuers and OIDC issuer verification needs to be disabled.
When not specified, all tenants are allowed. Redundant for single-tenant apps
(regular ID token validation matches the issuer). |
+| `federatedTokenAuth` | _bool_ | FederatedTokenAuth enable oAuth2 client authentication with federated token projected
by Entra Workload Identity plugin, instead of client secret. |
### OIDCOptions
diff --git a/docs/docs/configuration/providers/ms_entra_id.md b/docs/docs/configuration/providers/ms_entra_id.md
index 082d3247..ca9fc850 100644
--- a/docs/docs/configuration/providers/ms_entra_id.md
+++ b/docs/docs/configuration/providers/ms_entra_id.md
@@ -12,6 +12,7 @@ The provider is OIDC-compliant, so all the OIDC parameters are honored. Addition
| Flag | Toml Field | Type | Description | Default |
| --------------------------- | -------------------------- | -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------- |
| `--entra-id-allowed-tenant` | `entra_id_allowed_tenants` | string \| list | List of allowed tenants. In case of multi-tenant apps, incoming tokens are issued by different issuers and OIDC issuer verification needs to be disabled. When not specified, all tenants are allowed. Redundant for single-tenant apps (regular ID token validation matches the issuer). | |
+| `--entra-id-federated-token-auth` | `entra_id_federated_token_auth` | boolean | Enable oAuth2 client authentication with federated token projected by Entra Workload Identity plugin, instead of client secret. | false |
## Configure App registration
To begin, create an App registration, set a redirect URI, and generate a secret. All account types are supported, including single-tenant, multi-tenant, multi-tenant with Microsoft accounts, and Microsoft accounts only.
@@ -115,6 +116,34 @@ insecure_oidc_skip_issuer_verification=true
To provide additional security, Entra ID provider performs check on the ID token's `issuer` claim to match the `https://login.microsoftonline.com/{tenant-id}/v2.0` template.
+### Workload Identity
+Provider supports authentication with federated token, without need of using client secret. Following conditions have to be met:
+
+* Cluster has public OIDC provider URL. For major cloud providers, it can be enabled with a single flag, for example for [Azure Kubernetes Service deployed with Terraform](https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/kubernetes_cluster), it's `oidc_issuer_enabled`.
+* Workload Identity admission webhook is deployed on the cluster. For AKS, it can be enabled with a flag (`workload_identity_enabled` in Terraform resource), for clusters outside of Azure, it can be installed from [helm chart](https://github.com/Azure/azure-workload-identity).
+* Appropriate federated credential is added to application registration.
+
+ See federated credential terraform example
+```
+ resource "azuread_application_federated_identity_credential" "fedcred" {
+ application_id = azuread_application.application.id # ID of your application
+ display_name = "federation-cred"
+ description = "Workload identity for oauth2-proxy"
+ audiences = ["api://AzureADTokenExchange"] # Fixed value
+ issuer = "https://cluster-oidc-issuer-url..."
+ subject = "system:serviceaccount:oauth2-proxy-namespace-name:oauth2-proxy-sa-name" # set proper NS and SA name
+ }
+```
+
+
+* Kubernetes service account associated with oauth2-proxy deployment, is annotated with `azure.workload.identity/client-id: `
+* oauth2-proxy pod is labeled with `azure.workload.identity/use: "true"`
+* oauth2-proxy is configured with `entra_id_federated_token_auth` set to `true`.
+
+`client_secret` setting can be omitted when using federated token authentication.
+
+See: [Azure Workload Identity documentation](https://azure.github.io/azure-workload-identity/docs/).
+
### Example configurations
Single-tenant app without groups (*groups claim* not enabled). Consider using generic OIDC provider:
```toml
@@ -145,6 +174,16 @@ scope="openid User.Read"
allowed_groups=["968b4844-d5e7-4e18-a834-59927959369f"]
```
+Single-tenant app with more than 200 groups and workload identity enabled:
+```toml
+provider="entra-id"
+oidc_issuer_url="https://login.microsoftonline.com//v2.0"
+client_id=""
+scope="openid User.Read"
+allowed_groups=["968b4844-d5e7-4e18-a834-59927959369f"]
+entra_id_federated_token_auth=true
+```
+
Multi-tenant app with Microsoft personal accounts & one Entra tenant allowed, with group overage considered:
```toml
provider="entra-id"
diff --git a/pkg/apis/options/legacy_options.go b/pkg/apis/options/legacy_options.go
index ed7ae7b1..6cf9ba8d 100644
--- a/pkg/apis/options/legacy_options.go
+++ b/pkg/apis/options/legacy_options.go
@@ -489,6 +489,7 @@ type LegacyProvider struct {
AzureTenant string `flag:"azure-tenant" cfg:"azure_tenant"`
AzureGraphGroupField string `flag:"azure-graph-group-field" cfg:"azure_graph_group_field"`
EntraIDAllowedTenants []string `flag:"entra-id-allowed-tenant" cfg:"entra_id_allowed_tenants"`
+ EntraIDFederatedTokenAuth bool `flag:"entra-id-federated-token-auth" cfg:"entra_id_federated_token_auth"`
BitbucketTeam string `flag:"bitbucket-team" cfg:"bitbucket_team"`
BitbucketRepository string `flag:"bitbucket-repository" cfg:"bitbucket_repository"`
GitHubOrg string `flag:"github-org" cfg:"github_org"`
@@ -552,6 +553,7 @@ func legacyProviderFlagSet() *pflag.FlagSet {
flagSet.String("azure-tenant", "common", "go to a tenant-specific or common (tenant-independent) endpoint.")
flagSet.String("azure-graph-group-field", "", "configures the group field to be used when building the groups list(`id` or `displayName`. Default is `id`) from Microsoft Graph(available only for v2.0 oidc url). Based on this value, the `allowed-group` config values should be adjusted accordingly. If using `id` as group field, `allowed-group` should contains groups IDs, if using `displayName` as group field, `allowed-group` should contains groups name")
flagSet.StringSlice("entra-id-allowed-tenant", []string{}, "list of tenants allowed for MS Entra ID multi-tenant application")
+ flagSet.Bool("entra-id-federated-token-auth", false, "enable oAuth client authentication with federated token projected by Azure Workload Identity plugin, instead of client secret.")
flagSet.String("bitbucket-team", "", "restrict logins to members of this team")
flagSet.String("bitbucket-repository", "", "restrict logins to user with access to this repository")
flagSet.String("github-org", "", "restrict logins to members of this organisation")
@@ -760,7 +762,8 @@ func (l *LegacyProvider) convert() (Providers, error) {
}
case "entra-id":
provider.MicrosoftEntraIDConfig = MicrosoftEntraIDOptions{
- AllowedTenants: l.EntraIDAllowedTenants,
+ AllowedTenants: l.EntraIDAllowedTenants,
+ FederatedTokenAuth: l.EntraIDFederatedTokenAuth,
}
}
diff --git a/pkg/apis/options/providers.go b/pkg/apis/options/providers.go
index 72df5633..740a0d0f 100644
--- a/pkg/apis/options/providers.go
+++ b/pkg/apis/options/providers.go
@@ -166,6 +166,10 @@ type MicrosoftEntraIDOptions struct {
// When not specified, all tenants are allowed. Redundant for single-tenant apps
// (regular ID token validation matches the issuer).
AllowedTenants []string `json:"allowedTenants,omitempty"`
+
+ // FederatedTokenAuth enable oAuth2 client authentication with federated token projected
+ // by Entra Workload Identity plugin, instead of client secret.
+ FederatedTokenAuth bool `json:"federatedTokenAuth,omitempty"`
}
type ADFSOptions struct {
diff --git a/pkg/validation/providers.go b/pkg/validation/providers.go
index ecc2d06d..b1106b35 100644
--- a/pkg/validation/providers.go
+++ b/pkg/validation/providers.go
@@ -46,20 +46,47 @@ func validateProvider(provider options.Provider, providerIDs map[string]struct{}
msgs = append(msgs, "provider missing setting: client-id")
}
- // login.gov uses a signed JWT to authenticate, not a client-secret
- if provider.Type != "login.gov" {
- if provider.ClientSecret == "" && provider.ClientSecretFile == "" {
- msgs = append(msgs, "missing setting: client-secret or client-secret-file")
- }
- if provider.ClientSecret == "" && provider.ClientSecretFile != "" {
- _, err := os.ReadFile(provider.ClientSecretFile)
- if err != nil {
- msgs = append(msgs, "could not read client secret file: "+provider.ClientSecretFile)
- }
- }
+ if providerRequiresClientSecret(provider) {
+ msgs = append(msgs, validateClientSecret(provider)...)
}
- msgs = append(msgs, validateGoogleConfig(provider)...)
+ if provider.Type == "google" {
+ msgs = append(msgs, validateGoogleConfig(provider)...)
+ }
+
+ if provider.Type == "entra-id" {
+ msgs = append(msgs, validateEntraConfig(provider)...)
+ }
+
+ return msgs
+}
+
+// providerRequiresClientSecret checks if provider requires client secret to be set
+// or it can be omitted in favor of JWT token to authenticate oAuth client
+func providerRequiresClientSecret(provider options.Provider) bool {
+ if provider.Type == "entra-id" && provider.MicrosoftEntraIDConfig.FederatedTokenAuth {
+ return false
+ }
+
+ if provider.Type == "login.gov" {
+ return false
+ }
+
+ return true
+}
+
+func validateClientSecret(provider options.Provider) []string {
+ msgs := []string{}
+
+ if provider.ClientSecret == "" && provider.ClientSecretFile == "" {
+ msgs = append(msgs, "missing setting: client-secret or client-secret-file")
+ }
+ if provider.ClientSecret == "" && provider.ClientSecretFile != "" {
+ _, err := os.ReadFile(provider.ClientSecretFile)
+ if err != nil {
+ msgs = append(msgs, "could not read client secret file: "+provider.ClientSecretFile)
+ }
+ }
return msgs
}
@@ -96,3 +123,23 @@ func validateGoogleConfig(provider options.Provider) []string {
return msgs
}
+
+func validateEntraConfig(provider options.Provider) []string {
+ msgs := []string{}
+
+ if provider.MicrosoftEntraIDConfig.FederatedTokenAuth {
+ federatedTokenPath := os.Getenv("AZURE_FEDERATED_TOKEN_FILE")
+
+ if federatedTokenPath == "" {
+ msgs = append(msgs, "entra federated token authentication is enabled, but AZURE_FEDERATED_TOKEN_FILE variable is not set, check your workload identity configuration.")
+ return msgs
+ }
+
+ _, err := os.ReadFile(federatedTokenPath)
+ if err != nil {
+ msgs = append(msgs, "could not read entra federated token file")
+ }
+ }
+
+ return msgs
+}
diff --git a/providers/ms_entra_id.go b/providers/ms_entra_id.go
index 74061701..330c7875 100644
--- a/providers/ms_entra_id.go
+++ b/providers/ms_entra_id.go
@@ -1,9 +1,12 @@
package providers
import (
+ "bytes"
"context"
+ "encoding/json"
"fmt"
"net/url"
+ "os"
"regexp"
"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/apis/options"
@@ -12,12 +15,14 @@ import (
"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/requests"
"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/util"
"github.com/spf13/cast"
+ "golang.org/x/oauth2"
)
// MicrosoftEntraIDProvider represents provider for Azure Entra Authentication V2 endpoint
type MicrosoftEntraIDProvider struct {
*OIDCProvider
multiTenantAllowedTenants []string
+ federatedTokenAuth bool
microsoftGraphURL *url.URL
}
@@ -44,6 +49,7 @@ func NewMicrosoftEntraIDProvider(p *ProviderData, opts options.Provider) *Micros
OIDCProvider: NewOIDCProvider(p, opts.OIDCConfig),
multiTenantAllowedTenants: opts.MicrosoftEntraIDConfig.AllowedTenants,
+ federatedTokenAuth: opts.MicrosoftEntraIDConfig.FederatedTokenAuth,
microsoftGraphURL: microsoftGraphURL,
}
}
@@ -89,6 +95,61 @@ func (p *MicrosoftEntraIDProvider) ValidateSession(ctx context.Context, session
return p.OIDCProvider.ValidateSession(ctx, session)
}
+// Redeem exchanges the OAuth2 authentication token for an ID token, considering federated token authentication
+func (p *MicrosoftEntraIDProvider) Redeem(ctx context.Context, redirectURL, code, codeVerifier string) (*sessions.SessionState, error) {
+ if p.federatedTokenAuth {
+ return p.redeemWithFederatedToken(ctx, redirectURL, code, codeVerifier)
+ }
+
+ return p.OIDCProvider.Redeem(ctx, redirectURL, code, codeVerifier)
+}
+
+// redeemWithFederatedToken performs custom token exchange with federated token instead of client secret
+func (p *MicrosoftEntraIDProvider) redeemWithFederatedToken(ctx context.Context, redirectURL, code, codeVerifier string) (*sessions.SessionState, error) {
+ federatedTokenPath := os.Getenv("AZURE_FEDERATED_TOKEN_FILE")
+ federatedToken, err := os.ReadFile(federatedTokenPath)
+ if err != nil {
+ return nil, fmt.Errorf("error reading federated token file %s: %s", federatedTokenPath, err)
+ }
+
+ params := url.Values{}
+
+ // create custom exchange parameters
+ if codeVerifier != "" {
+ params.Add("code_verifier", codeVerifier)
+ }
+ params.Add("redirect_uri", redirectURL)
+ params.Add("client_id", p.ClientID)
+ params.Add("client_assertion", string(federatedToken))
+ params.Add("client_assertion_type", "urn:ietf:params:oauth:client-assertion-type:jwt-bearer")
+ params.Add("code", code)
+ params.Add("grant_type", "authorization_code")
+
+ // perform exchange
+ resp := requests.New(p.RedeemURL.String()).
+ WithContext(ctx).
+ WithMethod("POST").
+ WithBody(bytes.NewBufferString(params.Encode())).
+ SetHeader("Content-Type", "application/x-www-form-urlencoded").
+ Do()
+
+ // prepare token of type *oauth2.Token
+ var token *oauth2.Token
+ var rawResponse interface{}
+
+ body := resp.Body()
+ if err := json.Unmarshal(body, &rawResponse); err != nil {
+ return nil, err
+ }
+
+ if err := json.Unmarshal(body, &token); err != nil {
+ return nil, err
+ }
+
+ // create session using new token and generic OIDC provider
+ return p.OIDCProvider.createSession(ctx, token.WithExtra(rawResponse), false)
+}
+
// checkGroupOverage checks ID token's group membership claims for the group overage
func (p *MicrosoftEntraIDProvider) checkGroupOverage(session *sessions.SessionState) (bool, error) {
extractor, err := p.getClaimExtractor(session.IDToken, session.AccessToken)