Allow additional claims to map into an ID token issued by the supervisor

- Specify mappings on OIDCIdentityProvider.spec.claims.additionalClaimMappings
- Advertise additionalClaims in the OIDC discovery endpoint under claims_supported

Co-authored-by: Ryan Richard <richardry@vmware.com>
Co-authored-by: Joshua Casey <joshuatcasey@gmail.com>

apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go.tmpl

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

apis/supervisor/oidc/types_supervisor_oidc.go.tmpl

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

deploy/supervisor/idp.supervisor.pinniped.dev_oidcidentityproviders.yaml

@@ -185,6 +185,24 @@ spec:
                 description: Claims provides the names of token claims that will be
                   used when inspecting an identity from this OIDC identity provider.
                 properties:
+                  additionalClaimMappings:
+                    additionalProperties:
+                      type: string
+                    description: AdditionalClaimMappings allows for additional arbitrary
+                      upstream claim values to be mapped into the "additionalClaims"
+                      claim of the ID tokens generated by the Supervisor. This should
+                      be specified as a map of new claim names as the keys, and upstream
+                      claim names as the values. These new claim names will be nested
+                      under the top-level "additionalClaims" claim in ID tokens generated
+                      by the Supervisor when this OIDCIdentityProvider was used for
+                      user authentication. These claims will be made available to
+                      all clients. This feature is not required to use the Supervisor
+                      to provide authentication for Kubernetes clusters, but can be
+                      used when using the Supervisor for other authentication purposes.
+                      When this map is empty or the upstream claims are not available,
+                      the "additionalClaims" claim will be excluded from the ID tokens
+                      generated by the Supervisor.
+                    type: object
                   groups:
                     description: Groups provides the name of the ID token claim or
                       userinfo endpoint response claim that will be used to ascertain

generated/1.17/README.adoc

@@ -1391,6 +1391,7 @@ OIDCClaims provides a mapping from upstream claims into identities.
 | Field | Description
 | *`groups`* __string__ | Groups provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain the groups to which an identity belongs. By default, the identities will not include any group memberships when this setting is not configured.
 | *`username`* __string__ | Username provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain an identity's username. When not set, the username will be an automatically constructed unique string which will include the issuer URL of your OIDC provider along with the value of the "sub" (subject) claim from the ID token.
+| *`additionalClaimMappings`* __object (keys:string, values:string)__ | AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of new claim names as the keys, and upstream claim names as the values. These new claim names will be nested under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients. This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
 |===
 
 

generated/1.17/apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

generated/1.17/apis/supervisor/idp/v1alpha1/zz_generated.deepcopy.go

@@ -438,6 +438,13 @@ func (in *OIDCAuthorizationConfig) DeepCopy() *OIDCAuthorizationConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OIDCClaims) DeepCopyInto(out *OIDCClaims) {
 	*out = *in
+	if in.AdditionalClaimMappings != nil {
+		in, out := &in.AdditionalClaimMappings, &out.AdditionalClaimMappings
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -537,7 +544,7 @@ func (in *OIDCIdentityProviderSpec) DeepCopyInto(out *OIDCIdentityProviderSpec)
 		**out = **in
 	}
 	in.AuthorizationConfig.DeepCopyInto(&out.AuthorizationConfig)
-	out.Claims = in.Claims
+	in.Claims.DeepCopyInto(&out.Claims)
 	out.Client = in.Client
 	return
 }

generated/1.17/apis/supervisor/oidc/types_supervisor_oidc.go

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

generated/1.17/crds/idp.supervisor.pinniped.dev_oidcidentityproviders.yaml

@@ -185,6 +185,24 @@ spec:
                 description: Claims provides the names of token claims that will be
                   used when inspecting an identity from this OIDC identity provider.
                 properties:
+                  additionalClaimMappings:
+                    additionalProperties:
+                      type: string
+                    description: AdditionalClaimMappings allows for additional arbitrary
+                      upstream claim values to be mapped into the "additionalClaims"
+                      claim of the ID tokens generated by the Supervisor. This should
+                      be specified as a map of new claim names as the keys, and upstream
+                      claim names as the values. These new claim names will be nested
+                      under the top-level "additionalClaims" claim in ID tokens generated
+                      by the Supervisor when this OIDCIdentityProvider was used for
+                      user authentication. These claims will be made available to
+                      all clients. This feature is not required to use the Supervisor
+                      to provide authentication for Kubernetes clusters, but can be
+                      used when using the Supervisor for other authentication purposes.
+                      When this map is empty or the upstream claims are not available,
+                      the "additionalClaims" claim will be excluded from the ID tokens
+                      generated by the Supervisor.
+                    type: object
                   groups:
                     description: Groups provides the name of the ID token claim or
                       userinfo endpoint response claim that will be used to ascertain

generated/1.18/README.adoc

@@ -1391,6 +1391,7 @@ OIDCClaims provides a mapping from upstream claims into identities.
 | Field | Description
 | *`groups`* __string__ | Groups provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain the groups to which an identity belongs. By default, the identities will not include any group memberships when this setting is not configured.
 | *`username`* __string__ | Username provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain an identity's username. When not set, the username will be an automatically constructed unique string which will include the issuer URL of your OIDC provider along with the value of the "sub" (subject) claim from the ID token.
+| *`additionalClaimMappings`* __object (keys:string, values:string)__ | AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of new claim names as the keys, and upstream claim names as the values. These new claim names will be nested under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients. This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
 |===
 
 

generated/1.18/apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

generated/1.18/apis/supervisor/idp/v1alpha1/zz_generated.deepcopy.go

@@ -438,6 +438,13 @@ func (in *OIDCAuthorizationConfig) DeepCopy() *OIDCAuthorizationConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OIDCClaims) DeepCopyInto(out *OIDCClaims) {
 	*out = *in
+	if in.AdditionalClaimMappings != nil {
+		in, out := &in.AdditionalClaimMappings, &out.AdditionalClaimMappings
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -537,7 +544,7 @@ func (in *OIDCIdentityProviderSpec) DeepCopyInto(out *OIDCIdentityProviderSpec)
 		**out = **in
 	}
 	in.AuthorizationConfig.DeepCopyInto(&out.AuthorizationConfig)
-	out.Claims = in.Claims
+	in.Claims.DeepCopyInto(&out.Claims)
 	out.Client = in.Client
 	return
 }

generated/1.18/apis/supervisor/oidc/types_supervisor_oidc.go

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

generated/1.18/crds/idp.supervisor.pinniped.dev_oidcidentityproviders.yaml

@@ -185,6 +185,24 @@ spec:
                 description: Claims provides the names of token claims that will be
                   used when inspecting an identity from this OIDC identity provider.
                 properties:
+                  additionalClaimMappings:
+                    additionalProperties:
+                      type: string
+                    description: AdditionalClaimMappings allows for additional arbitrary
+                      upstream claim values to be mapped into the "additionalClaims"
+                      claim of the ID tokens generated by the Supervisor. This should
+                      be specified as a map of new claim names as the keys, and upstream
+                      claim names as the values. These new claim names will be nested
+                      under the top-level "additionalClaims" claim in ID tokens generated
+                      by the Supervisor when this OIDCIdentityProvider was used for
+                      user authentication. These claims will be made available to
+                      all clients. This feature is not required to use the Supervisor
+                      to provide authentication for Kubernetes clusters, but can be
+                      used when using the Supervisor for other authentication purposes.
+                      When this map is empty or the upstream claims are not available,
+                      the "additionalClaims" claim will be excluded from the ID tokens
+                      generated by the Supervisor.
+                    type: object
                   groups:
                     description: Groups provides the name of the ID token claim or
                       userinfo endpoint response claim that will be used to ascertain

generated/1.19/README.adoc

@@ -1391,6 +1391,7 @@ OIDCClaims provides a mapping from upstream claims into identities.
 | Field | Description
 | *`groups`* __string__ | Groups provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain the groups to which an identity belongs. By default, the identities will not include any group memberships when this setting is not configured.
 | *`username`* __string__ | Username provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain an identity's username. When not set, the username will be an automatically constructed unique string which will include the issuer URL of your OIDC provider along with the value of the "sub" (subject) claim from the ID token.
+| *`additionalClaimMappings`* __object (keys:string, values:string)__ | AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of new claim names as the keys, and upstream claim names as the values. These new claim names will be nested under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients. This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
 |===
 
 

generated/1.19/apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

generated/1.19/apis/supervisor/idp/v1alpha1/zz_generated.deepcopy.go

@@ -438,6 +438,13 @@ func (in *OIDCAuthorizationConfig) DeepCopy() *OIDCAuthorizationConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OIDCClaims) DeepCopyInto(out *OIDCClaims) {
 	*out = *in
+	if in.AdditionalClaimMappings != nil {
+		in, out := &in.AdditionalClaimMappings, &out.AdditionalClaimMappings
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -537,7 +544,7 @@ func (in *OIDCIdentityProviderSpec) DeepCopyInto(out *OIDCIdentityProviderSpec)
 		**out = **in
 	}
 	in.AuthorizationConfig.DeepCopyInto(&out.AuthorizationConfig)
-	out.Claims = in.Claims
+	in.Claims.DeepCopyInto(&out.Claims)
 	out.Client = in.Client
 	return
 }

generated/1.19/apis/supervisor/oidc/types_supervisor_oidc.go

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

generated/1.19/crds/idp.supervisor.pinniped.dev_oidcidentityproviders.yaml

@@ -185,6 +185,24 @@ spec:
                 description: Claims provides the names of token claims that will be
                   used when inspecting an identity from this OIDC identity provider.
                 properties:
+                  additionalClaimMappings:
+                    additionalProperties:
+                      type: string
+                    description: AdditionalClaimMappings allows for additional arbitrary
+                      upstream claim values to be mapped into the "additionalClaims"
+                      claim of the ID tokens generated by the Supervisor. This should
+                      be specified as a map of new claim names as the keys, and upstream
+                      claim names as the values. These new claim names will be nested
+                      under the top-level "additionalClaims" claim in ID tokens generated
+                      by the Supervisor when this OIDCIdentityProvider was used for
+                      user authentication. These claims will be made available to
+                      all clients. This feature is not required to use the Supervisor
+                      to provide authentication for Kubernetes clusters, but can be
+                      used when using the Supervisor for other authentication purposes.
+                      When this map is empty or the upstream claims are not available,
+                      the "additionalClaims" claim will be excluded from the ID tokens
+                      generated by the Supervisor.
+                    type: object
                   groups:
                     description: Groups provides the name of the ID token claim or
                       userinfo endpoint response claim that will be used to ascertain

generated/1.20/README.adoc

@@ -1391,6 +1391,7 @@ OIDCClaims provides a mapping from upstream claims into identities.
 | Field | Description
 | *`groups`* __string__ | Groups provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain the groups to which an identity belongs. By default, the identities will not include any group memberships when this setting is not configured.
 | *`username`* __string__ | Username provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain an identity's username. When not set, the username will be an automatically constructed unique string which will include the issuer URL of your OIDC provider along with the value of the "sub" (subject) claim from the ID token.
+| *`additionalClaimMappings`* __object (keys:string, values:string)__ | AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of new claim names as the keys, and upstream claim names as the values. These new claim names will be nested under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients. This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
 |===
 
 

generated/1.20/apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

generated/1.20/apis/supervisor/idp/v1alpha1/zz_generated.deepcopy.go

@@ -438,6 +438,13 @@ func (in *OIDCAuthorizationConfig) DeepCopy() *OIDCAuthorizationConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OIDCClaims) DeepCopyInto(out *OIDCClaims) {
 	*out = *in
+	if in.AdditionalClaimMappings != nil {
+		in, out := &in.AdditionalClaimMappings, &out.AdditionalClaimMappings
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -537,7 +544,7 @@ func (in *OIDCIdentityProviderSpec) DeepCopyInto(out *OIDCIdentityProviderSpec)
 		**out = **in
 	}
 	in.AuthorizationConfig.DeepCopyInto(&out.AuthorizationConfig)
-	out.Claims = in.Claims
+	in.Claims.DeepCopyInto(&out.Claims)
 	out.Client = in.Client
 	return
 }

generated/1.20/apis/supervisor/oidc/types_supervisor_oidc.go

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

generated/1.20/crds/idp.supervisor.pinniped.dev_oidcidentityproviders.yaml

@@ -185,6 +185,24 @@ spec:
                 description: Claims provides the names of token claims that will be
                   used when inspecting an identity from this OIDC identity provider.
                 properties:
+                  additionalClaimMappings:
+                    additionalProperties:
+                      type: string
+                    description: AdditionalClaimMappings allows for additional arbitrary
+                      upstream claim values to be mapped into the "additionalClaims"
+                      claim of the ID tokens generated by the Supervisor. This should
+                      be specified as a map of new claim names as the keys, and upstream
+                      claim names as the values. These new claim names will be nested
+                      under the top-level "additionalClaims" claim in ID tokens generated
+                      by the Supervisor when this OIDCIdentityProvider was used for
+                      user authentication. These claims will be made available to
+                      all clients. This feature is not required to use the Supervisor
+                      to provide authentication for Kubernetes clusters, but can be
+                      used when using the Supervisor for other authentication purposes.
+                      When this map is empty or the upstream claims are not available,
+                      the "additionalClaims" claim will be excluded from the ID tokens
+                      generated by the Supervisor.
+                    type: object
                   groups:
                     description: Groups provides the name of the ID token claim or
                       userinfo endpoint response claim that will be used to ascertain

generated/1.21/README.adoc

@@ -1391,6 +1391,7 @@ OIDCClaims provides a mapping from upstream claims into identities.
 | Field | Description
 | *`groups`* __string__ | Groups provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain the groups to which an identity belongs. By default, the identities will not include any group memberships when this setting is not configured.
 | *`username`* __string__ | Username provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain an identity's username. When not set, the username will be an automatically constructed unique string which will include the issuer URL of your OIDC provider along with the value of the "sub" (subject) claim from the ID token.
+| *`additionalClaimMappings`* __object (keys:string, values:string)__ | AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of new claim names as the keys, and upstream claim names as the values. These new claim names will be nested under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients. This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
 |===
 
 

generated/1.21/apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

generated/1.21/apis/supervisor/idp/v1alpha1/zz_generated.deepcopy.go

@@ -438,6 +438,13 @@ func (in *OIDCAuthorizationConfig) DeepCopy() *OIDCAuthorizationConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OIDCClaims) DeepCopyInto(out *OIDCClaims) {
 	*out = *in
+	if in.AdditionalClaimMappings != nil {
+		in, out := &in.AdditionalClaimMappings, &out.AdditionalClaimMappings
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -537,7 +544,7 @@ func (in *OIDCIdentityProviderSpec) DeepCopyInto(out *OIDCIdentityProviderSpec)
 		**out = **in
 	}
 	in.AuthorizationConfig.DeepCopyInto(&out.AuthorizationConfig)
-	out.Claims = in.Claims
+	in.Claims.DeepCopyInto(&out.Claims)
 	out.Client = in.Client
 	return
 }

generated/1.21/apis/supervisor/oidc/types_supervisor_oidc.go

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

generated/1.21/crds/idp.supervisor.pinniped.dev_oidcidentityproviders.yaml

@@ -185,6 +185,24 @@ spec:
                 description: Claims provides the names of token claims that will be
                   used when inspecting an identity from this OIDC identity provider.
                 properties:
+                  additionalClaimMappings:
+                    additionalProperties:
+                      type: string
+                    description: AdditionalClaimMappings allows for additional arbitrary
+                      upstream claim values to be mapped into the "additionalClaims"
+                      claim of the ID tokens generated by the Supervisor. This should
+                      be specified as a map of new claim names as the keys, and upstream
+                      claim names as the values. These new claim names will be nested
+                      under the top-level "additionalClaims" claim in ID tokens generated
+                      by the Supervisor when this OIDCIdentityProvider was used for
+                      user authentication. These claims will be made available to
+                      all clients. This feature is not required to use the Supervisor
+                      to provide authentication for Kubernetes clusters, but can be
+                      used when using the Supervisor for other authentication purposes.
+                      When this map is empty or the upstream claims are not available,
+                      the "additionalClaims" claim will be excluded from the ID tokens
+                      generated by the Supervisor.
+                    type: object
                   groups:
                     description: Groups provides the name of the ID token claim or
                       userinfo endpoint response claim that will be used to ascertain

generated/1.22/README.adoc

@@ -1391,6 +1391,7 @@ OIDCClaims provides a mapping from upstream claims into identities.
 | Field | Description
 | *`groups`* __string__ | Groups provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain the groups to which an identity belongs. By default, the identities will not include any group memberships when this setting is not configured.
 | *`username`* __string__ | Username provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain an identity's username. When not set, the username will be an automatically constructed unique string which will include the issuer URL of your OIDC provider along with the value of the "sub" (subject) claim from the ID token.
+| *`additionalClaimMappings`* __object (keys:string, values:string)__ | AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of new claim names as the keys, and upstream claim names as the values. These new claim names will be nested under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients. This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
 |===
 
 

generated/1.22/apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

generated/1.22/apis/supervisor/idp/v1alpha1/zz_generated.deepcopy.go

@@ -438,6 +438,13 @@ func (in *OIDCAuthorizationConfig) DeepCopy() *OIDCAuthorizationConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OIDCClaims) DeepCopyInto(out *OIDCClaims) {
 	*out = *in
+	if in.AdditionalClaimMappings != nil {
+		in, out := &in.AdditionalClaimMappings, &out.AdditionalClaimMappings
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -537,7 +544,7 @@ func (in *OIDCIdentityProviderSpec) DeepCopyInto(out *OIDCIdentityProviderSpec)
 		**out = **in
 	}
 	in.AuthorizationConfig.DeepCopyInto(&out.AuthorizationConfig)
-	out.Claims = in.Claims
+	in.Claims.DeepCopyInto(&out.Claims)
 	out.Client = in.Client
 	return
 }

generated/1.22/apis/supervisor/oidc/types_supervisor_oidc.go

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

generated/1.22/crds/idp.supervisor.pinniped.dev_oidcidentityproviders.yaml

@@ -185,6 +185,24 @@ spec:
                 description: Claims provides the names of token claims that will be
                   used when inspecting an identity from this OIDC identity provider.
                 properties:
+                  additionalClaimMappings:
+                    additionalProperties:
+                      type: string
+                    description: AdditionalClaimMappings allows for additional arbitrary
+                      upstream claim values to be mapped into the "additionalClaims"
+                      claim of the ID tokens generated by the Supervisor. This should
+                      be specified as a map of new claim names as the keys, and upstream
+                      claim names as the values. These new claim names will be nested
+                      under the top-level "additionalClaims" claim in ID tokens generated
+                      by the Supervisor when this OIDCIdentityProvider was used for
+                      user authentication. These claims will be made available to
+                      all clients. This feature is not required to use the Supervisor
+                      to provide authentication for Kubernetes clusters, but can be
+                      used when using the Supervisor for other authentication purposes.
+                      When this map is empty or the upstream claims are not available,
+                      the "additionalClaims" claim will be excluded from the ID tokens
+                      generated by the Supervisor.
+                    type: object
                   groups:
                     description: Groups provides the name of the ID token claim or
                       userinfo endpoint response claim that will be used to ascertain

generated/1.23/README.adoc

@@ -1391,6 +1391,7 @@ OIDCClaims provides a mapping from upstream claims into identities.
 | Field | Description
 | *`groups`* __string__ | Groups provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain the groups to which an identity belongs. By default, the identities will not include any group memberships when this setting is not configured.
 | *`username`* __string__ | Username provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain an identity's username. When not set, the username will be an automatically constructed unique string which will include the issuer URL of your OIDC provider along with the value of the "sub" (subject) claim from the ID token.
+| *`additionalClaimMappings`* __object (keys:string, values:string)__ | AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of new claim names as the keys, and upstream claim names as the values. These new claim names will be nested under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients. This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
 |===
 
 

generated/1.23/apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

generated/1.23/apis/supervisor/idp/v1alpha1/zz_generated.deepcopy.go

@@ -438,6 +438,13 @@ func (in *OIDCAuthorizationConfig) DeepCopy() *OIDCAuthorizationConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OIDCClaims) DeepCopyInto(out *OIDCClaims) {
 	*out = *in
+	if in.AdditionalClaimMappings != nil {
+		in, out := &in.AdditionalClaimMappings, &out.AdditionalClaimMappings
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -537,7 +544,7 @@ func (in *OIDCIdentityProviderSpec) DeepCopyInto(out *OIDCIdentityProviderSpec)
 		**out = **in
 	}
 	in.AuthorizationConfig.DeepCopyInto(&out.AuthorizationConfig)
-	out.Claims = in.Claims
+	in.Claims.DeepCopyInto(&out.Claims)
 	out.Client = in.Client
 	return
 }

generated/1.23/apis/supervisor/oidc/types_supervisor_oidc.go

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

generated/1.23/crds/idp.supervisor.pinniped.dev_oidcidentityproviders.yaml

@@ -185,6 +185,24 @@ spec:
                 description: Claims provides the names of token claims that will be
                   used when inspecting an identity from this OIDC identity provider.
                 properties:
+                  additionalClaimMappings:
+                    additionalProperties:
+                      type: string
+                    description: AdditionalClaimMappings allows for additional arbitrary
+                      upstream claim values to be mapped into the "additionalClaims"
+                      claim of the ID tokens generated by the Supervisor. This should
+                      be specified as a map of new claim names as the keys, and upstream
+                      claim names as the values. These new claim names will be nested
+                      under the top-level "additionalClaims" claim in ID tokens generated
+                      by the Supervisor when this OIDCIdentityProvider was used for
+                      user authentication. These claims will be made available to
+                      all clients. This feature is not required to use the Supervisor
+                      to provide authentication for Kubernetes clusters, but can be
+                      used when using the Supervisor for other authentication purposes.
+                      When this map is empty or the upstream claims are not available,
+                      the "additionalClaims" claim will be excluded from the ID tokens
+                      generated by the Supervisor.
+                    type: object
                   groups:
                     description: Groups provides the name of the ID token claim or
                       userinfo endpoint response claim that will be used to ascertain

generated/1.24/README.adoc

@@ -1391,6 +1391,7 @@ OIDCClaims provides a mapping from upstream claims into identities.
 | Field | Description
 | *`groups`* __string__ | Groups provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain the groups to which an identity belongs. By default, the identities will not include any group memberships when this setting is not configured.
 | *`username`* __string__ | Username provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain an identity's username. When not set, the username will be an automatically constructed unique string which will include the issuer URL of your OIDC provider along with the value of the "sub" (subject) claim from the ID token.
+| *`additionalClaimMappings`* __object (keys:string, values:string)__ | AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of new claim names as the keys, and upstream claim names as the values. These new claim names will be nested under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients. This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
 |===
 
 

generated/1.24/apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

generated/1.24/apis/supervisor/idp/v1alpha1/zz_generated.deepcopy.go

@@ -438,6 +438,13 @@ func (in *OIDCAuthorizationConfig) DeepCopy() *OIDCAuthorizationConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OIDCClaims) DeepCopyInto(out *OIDCClaims) {
 	*out = *in
+	if in.AdditionalClaimMappings != nil {
+		in, out := &in.AdditionalClaimMappings, &out.AdditionalClaimMappings
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -537,7 +544,7 @@ func (in *OIDCIdentityProviderSpec) DeepCopyInto(out *OIDCIdentityProviderSpec)
 		**out = **in
 	}
 	in.AuthorizationConfig.DeepCopyInto(&out.AuthorizationConfig)
-	out.Claims = in.Claims
+	in.Claims.DeepCopyInto(&out.Claims)
 	out.Client = in.Client
 	return
 }

generated/1.24/apis/supervisor/oidc/types_supervisor_oidc.go

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

generated/1.24/crds/idp.supervisor.pinniped.dev_oidcidentityproviders.yaml

@@ -185,6 +185,24 @@ spec:
                 description: Claims provides the names of token claims that will be
                   used when inspecting an identity from this OIDC identity provider.
                 properties:
+                  additionalClaimMappings:
+                    additionalProperties:
+                      type: string
+                    description: AdditionalClaimMappings allows for additional arbitrary
+                      upstream claim values to be mapped into the "additionalClaims"
+                      claim of the ID tokens generated by the Supervisor. This should
+                      be specified as a map of new claim names as the keys, and upstream
+                      claim names as the values. These new claim names will be nested
+                      under the top-level "additionalClaims" claim in ID tokens generated
+                      by the Supervisor when this OIDCIdentityProvider was used for
+                      user authentication. These claims will be made available to
+                      all clients. This feature is not required to use the Supervisor
+                      to provide authentication for Kubernetes clusters, but can be
+                      used when using the Supervisor for other authentication purposes.
+                      When this map is empty or the upstream claims are not available,
+                      the "additionalClaims" claim will be excluded from the ID tokens
+                      generated by the Supervisor.
+                    type: object
                   groups:
                     description: Groups provides the name of the ID token claim or
                       userinfo endpoint response claim that will be used to ascertain

generated/1.25/README.adoc

@@ -1387,6 +1387,7 @@ OIDCClaims provides a mapping from upstream claims into identities.
 | Field | Description
 | *`groups`* __string__ | Groups provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain the groups to which an identity belongs. By default, the identities will not include any group memberships when this setting is not configured.
 | *`username`* __string__ | Username provides the name of the ID token claim or userinfo endpoint response claim that will be used to ascertain an identity's username. When not set, the username will be an automatically constructed unique string which will include the issuer URL of your OIDC provider along with the value of the "sub" (subject) claim from the ID token.
+| *`additionalClaimMappings`* __object (keys:string, values:string)__ | AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of new claim names as the keys, and upstream claim names as the values. These new claim names will be nested under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients. This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
 |===
 
 

generated/1.25/apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

generated/1.25/apis/supervisor/idp/v1alpha1/zz_generated.deepcopy.go

@@ -438,6 +438,13 @@ func (in *OIDCAuthorizationConfig) DeepCopy() *OIDCAuthorizationConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OIDCClaims) DeepCopyInto(out *OIDCClaims) {
 	*out = *in
+	if in.AdditionalClaimMappings != nil {
+		in, out := &in.AdditionalClaimMappings, &out.AdditionalClaimMappings
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -537,7 +544,7 @@ func (in *OIDCIdentityProviderSpec) DeepCopyInto(out *OIDCIdentityProviderSpec)
 		**out = **in
 	}
 	in.AuthorizationConfig.DeepCopyInto(&out.AuthorizationConfig)
-	out.Claims = in.Claims
+	in.Claims.DeepCopyInto(&out.Claims)
 	out.Client = in.Client
 	return
 }

generated/1.25/apis/supervisor/oidc/types_supervisor_oidc.go

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

generated/1.25/crds/idp.supervisor.pinniped.dev_oidcidentityproviders.yaml

@@ -185,6 +185,24 @@ spec:
                 description: Claims provides the names of token claims that will be
                   used when inspecting an identity from this OIDC identity provider.
                 properties:
+                  additionalClaimMappings:
+                    additionalProperties:
+                      type: string
+                    description: AdditionalClaimMappings allows for additional arbitrary
+                      upstream claim values to be mapped into the "additionalClaims"
+                      claim of the ID tokens generated by the Supervisor. This should
+                      be specified as a map of new claim names as the keys, and upstream
+                      claim names as the values. These new claim names will be nested
+                      under the top-level "additionalClaims" claim in ID tokens generated
+                      by the Supervisor when this OIDCIdentityProvider was used for
+                      user authentication. These claims will be made available to
+                      all clients. This feature is not required to use the Supervisor
+                      to provide authentication for Kubernetes clusters, but can be
+                      used when using the Supervisor for other authentication purposes.
+                      When this map is empty or the upstream claims are not available,
+                      the "additionalClaims" claim will be excluded from the ID tokens
+                      generated by the Supervisor.
+                    type: object
                   groups:
                     description: Groups provides the name of the ID token claim or
                       userinfo endpoint response claim that will be used to ascertain

generated/latest/apis/supervisor/idp/v1alpha1/types_oidcidentityprovider.go

@@ -138,6 +138,17 @@ type OIDCClaims struct {
 	// the ID token.
 	// +optional
 	Username string `json:"username"`
+
+	// AdditionalClaimMappings allows for additional arbitrary upstream claim values to be mapped into the
+	// "additionalClaims" claim of the ID tokens generated by the Supervisor. This should be specified as a map of
+	// new claim names as the keys, and upstream claim names as the values. These new claim names will be nested
+	// under the top-level "additionalClaims" claim in ID tokens generated by the Supervisor when this
+	// OIDCIdentityProvider was used for user authentication. These claims will be made available to all clients.
+	// This feature is not required to use the Supervisor to provide authentication for Kubernetes clusters, but can be
+	// used when using the Supervisor for other authentication purposes. When this map is empty or the upstream claims
+	// are not available, the "additionalClaims" claim will be excluded from the ID tokens generated by the Supervisor.
+	// +optional
+	AdditionalClaimMappings map[string]string `json:"additionalClaimMappings,omitempty"`
 }
 
 // OIDCClient contains information about an OIDC client (e.g., client ID and client

generated/latest/apis/supervisor/idp/v1alpha1/zz_generated.deepcopy.go

@@ -438,6 +438,13 @@ func (in *OIDCAuthorizationConfig) DeepCopy() *OIDCAuthorizationConfig {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *OIDCClaims) DeepCopyInto(out *OIDCClaims) {
 	*out = *in
+	if in.AdditionalClaimMappings != nil {
+		in, out := &in.AdditionalClaimMappings, &out.AdditionalClaimMappings
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -537,7 +544,7 @@ func (in *OIDCIdentityProviderSpec) DeepCopyInto(out *OIDCIdentityProviderSpec)
 		**out = **in
 	}
 	in.AuthorizationConfig.DeepCopyInto(&out.AuthorizationConfig)
-	out.Claims = in.Claims
+	in.Claims.DeepCopyInto(&out.Claims)
 	out.Client = in.Client
 	return
 }

generated/latest/apis/supervisor/oidc/types_supervisor_oidc.go

@@ -40,6 +40,10 @@ const (
 	// group names which were mapped from the upstream identity provider.
 	IDTokenClaimGroups = "groups"
 
+	// IDTokenClaimAdditionalClaims is the top level claim used to hold additional claims in the downstream ID
+	// token, if any claims are present.
+	IDTokenClaimAdditionalClaims = "additionalClaims"
+
 	// GrantTypeAuthorizationCode is the name of the grant type for authorization code flows defined by the OIDC spec.
 	GrantTypeAuthorizationCode = "authorization_code"
 

internal/controller/supervisorconfig/oidcupstreamwatcher/oidc_upstream_watcher.go

@@ -215,6 +215,7 @@ func (c *oidcWatcherController) validateUpstream(ctx controllerlib.Context, upst
 		GroupsClaim:              upstream.Spec.Claims.Groups,
 		AllowPasswordGrant:       authorizationConfig.AllowPasswordGrant,
 		AdditionalAuthcodeParams: additionalAuthcodeAuthorizeParameters,
+		AdditionalClaimMappings:  upstream.Spec.Claims.AdditionalClaimMappings,
 		ResourceUID:              upstream.UID,
 	}
 

internal/controller/supervisorconfig/oidcupstreamwatcher/oidc_upstream_watcher_test.go

@@ -999,6 +999,7 @@ Get "` + testIssuerURL + `/valid-url-that-is-really-really-long-nananananananana
 					GroupsClaim:              testGroupsClaim,
 					AllowPasswordGrant:       true,
 					AdditionalAuthcodeParams: map[string]string{},
+					AdditionalClaimMappings:  nil, // Does not default to empty map
 					ResourceUID:              testUID,
 				},
 			},
@@ -1054,6 +1055,7 @@ Get "` + testIssuerURL + `/valid-url-that-is-really-really-long-nananananananana
 					GroupsClaim:              testGroupsClaim,
 					AllowPasswordGrant:       false,
 					AdditionalAuthcodeParams: map[string]string{},
+					AdditionalClaimMappings:  nil, // Does not default to empty map
 					ResourceUID:              testUID,
 				},
 			},
@@ -1109,6 +1111,7 @@ Get "` + testIssuerURL + `/valid-url-that-is-really-really-long-nananananananana
 					GroupsClaim:              testGroupsClaim,
 					AllowPasswordGrant:       false,
 					AdditionalAuthcodeParams: map[string]string{},
+					AdditionalClaimMappings:  nil, // Does not default to empty map
 					ResourceUID:              testUID,
 				},
 			},
@@ -1167,6 +1170,7 @@ Get "` + testIssuerURL + `/valid-url-that-is-really-really-long-nananananananana
 					GroupsClaim:              testGroupsClaim,
 					AllowPasswordGrant:       false,
 					AdditionalAuthcodeParams: map[string]string{},
+					AdditionalClaimMappings:  nil, // Does not default to empty map
 					ResourceUID:              testUID,
 				},
 			},
@@ -1195,7 +1199,13 @@ Get "` + testIssuerURL + `/valid-url-that-is-really-really-long-nananananananana
 						AdditionalAuthorizeParameters: testAdditionalParams,
 						AllowPasswordGrant:            true,
 					},
-					Claims: v1alpha1.OIDCClaims{Groups: testGroupsClaim, Username: testUsernameClaim},
+					Claims: v1alpha1.OIDCClaims{
+						Groups:   testGroupsClaim,
+						Username: testUsernameClaim,
+						AdditionalClaimMappings: map[string]string{
+							"downstream": "upstream",
+						},
+					},
 				},
 				Status: v1alpha1.OIDCIdentityProviderStatus{
 					Phase: "Ready",
@@ -1227,7 +1237,10 @@ Get "` + testIssuerURL + `/valid-url-that-is-really-really-long-nananananananana
 					GroupsClaim:              testGroupsClaim,
 					AllowPasswordGrant:       true,
 					AdditionalAuthcodeParams: testExpectedAdditionalParams,
-					ResourceUID:              testUID,
+					AdditionalClaimMappings: map[string]string{
+						"downstream": "upstream",
+					},
+					ResourceUID: testUID,
 				},
 			},
 			wantResultingUpstreams: []v1alpha1.OIDCIdentityProvider{{
@@ -1442,6 +1455,7 @@ oidc: issuer did not match the issuer returned by provider, expected "` + testIs
 				require.Equal(t, tt.wantResultingCache[i].GetGroupsClaim(), actualIDP.GetGroupsClaim())
 				require.Equal(t, tt.wantResultingCache[i].AllowsPasswordGrant(), actualIDP.AllowsPasswordGrant())
 				require.Equal(t, tt.wantResultingCache[i].GetAdditionalAuthcodeParams(), actualIDP.GetAdditionalAuthcodeParams())
+				require.Equal(t, tt.wantResultingCache[i].GetAdditionalClaimMappings(), actualIDP.GetAdditionalClaimMappings())
 				require.Equal(t, tt.wantResultingCache[i].GetResourceUID(), actualIDP.GetResourceUID())
 				require.Equal(t, tt.wantResultingCache[i].GetRevocationURL(), actualIDP.GetRevocationURL())
 				require.ElementsMatch(t, tt.wantResultingCache[i].GetScopes(), actualIDP.GetScopes())

internal/mocks/mockupstreamoidcidentityprovider/mockupstreamoidcidentityprovider.go

@@ -88,6 +88,20 @@ func (mr *MockUpstreamOIDCIdentityProviderIMockRecorder) GetAdditionalAuthcodePa
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetAdditionalAuthcodeParams", reflect.TypeOf((*MockUpstreamOIDCIdentityProviderI)(nil).GetAdditionalAuthcodeParams))
 }
 
+// GetAdditionalClaimMappings mocks base method.
+func (m *MockUpstreamOIDCIdentityProviderI) GetAdditionalClaimMappings() map[string]string {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "GetAdditionalClaimMappings")
+	ret0, _ := ret[0].(map[string]string)
+	return ret0
+}
+
+// GetAdditionalClaimMappings indicates an expected call of GetAdditionalClaimMappings.
+func (mr *MockUpstreamOIDCIdentityProviderIMockRecorder) GetAdditionalClaimMappings() *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetAdditionalClaimMappings", reflect.TypeOf((*MockUpstreamOIDCIdentityProviderI)(nil).GetAdditionalClaimMappings))
+}
+
 // GetAuthorizationURL mocks base method.
 func (m *MockUpstreamOIDCIdentityProviderI) GetAuthorizationURL() *url.URL {
 	m.ctrl.T.Helper()

internal/oidc/auth/auth_handler.go

@@ -150,7 +150,7 @@ func handleAuthRequestForLDAPUpstreamCLIFlow(
 	groups := authenticateResponse.User.GetGroups()
 	customSessionData := downstreamsession.MakeDownstreamLDAPOrADCustomSessionData(ldapUpstream, idpType, authenticateResponse, username)
 	openIDSession := downstreamsession.MakeDownstreamSession(subject, username, groups,
-		authorizeRequester.GetGrantedScopes(), authorizeRequester.GetClient().GetID(), customSessionData)
+		authorizeRequester.GetGrantedScopes(), authorizeRequester.GetClient().GetID(), customSessionData, map[string]interface{}{})
 	oidc.PerformAuthcodeRedirect(r, w, oauthHelper, authorizeRequester, openIDSession, true)
 
 	return nil
@@ -243,6 +243,8 @@ func handleAuthRequestForOIDCUpstreamPasswordGrant(
 		return nil
 	}
 
+	additionalClaims := downstreamsession.MapAdditionalClaimsFromUpstreamIDToken(oidcUpstream, token.IDToken.Claims)
+
 	customSessionData, err := downstreamsession.MakeDownstreamOIDCCustomSessionData(oidcUpstream, token, username)
 	if err != nil {
 		oidc.WriteAuthorizeError(r, w, oauthHelper, authorizeRequester,
@@ -252,7 +254,7 @@ func handleAuthRequestForOIDCUpstreamPasswordGrant(
 	}
 
 	openIDSession := downstreamsession.MakeDownstreamSession(subject, username, groups,
-		authorizeRequester.GetGrantedScopes(), authorizeRequester.GetClient().GetID(), customSessionData)
+		authorizeRequester.GetGrantedScopes(), authorizeRequester.GetClient().GetID(), customSessionData, additionalClaims)
 
 	oidc.PerformAuthcodeRedirect(r, w, oauthHelper, authorizeRequester, openIDSession, true)
 

internal/oidc/auth/auth_handler_test.go

@@ -582,6 +582,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 		wantUnnecessaryStoredRecords      int
 		wantPasswordGrantCall             *expectedPasswordGrant
 		wantDownstreamCustomSessionData   *psession.CustomSessionData
+		wantAdditionalClaims              map[string]interface{}
 	}
 	tests := []testCase{
 		{
@@ -711,6 +712,68 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
 			wantDownstreamCustomSessionData:   expectedHappyOIDCPasswordGrantCustomSession,
 		},
+		{
+			name: "OIDC upstream password grant happy path using GET with additional claim mappings",
+			idps: oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(passwordGrantUpstreamOIDCIdentityProviderBuilder().
+				WithAdditionalClaimMappings(map[string]string{
+					"downstreamCustomClaim":  "upstreamCustomClaim",
+					"downstreamOtherClaim":   "upstreamOtherClaim",
+					"downstreamMissingClaim": "upstreamMissingClaim",
+				}).
+				WithIDTokenClaim("upstreamCustomClaim", "i am a claim value").
+				WithIDTokenClaim("upstreamOtherClaim", "other claim value").
+				Build()),
+			method:                            http.MethodGet,
+			path:                              happyGetRequestPath,
+			customUsernameHeader:              pointer.String(oidcUpstreamUsername),
+			customPasswordHeader:              pointer.String(oidcUpstreamPassword),
+			wantPasswordGrantCall:             happyUpstreamPasswordGrantMockExpectation,
+			wantStatus:                        http.StatusFound,
+			wantContentType:                   htmlContentType,
+			wantRedirectLocationRegexp:        happyAuthcodeDownstreamRedirectLocationRegexp,
+			wantDownstreamIDTokenSubject:      oidcUpstreamIssuer + "?sub=" + oidcUpstreamSubjectQueryEscaped,
+			wantDownstreamIDTokenUsername:     oidcUpstreamUsername,
+			wantDownstreamIDTokenGroups:       oidcUpstreamGroupMembership,
+			wantDownstreamRequestedScopes:     happyDownstreamScopesRequested,
+			wantDownstreamRedirectURI:         downstreamRedirectURI,
+			wantDownstreamGrantedScopes:       happyDownstreamScopesGranted,
+			wantDownstreamNonce:               downstreamNonce,
+			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
+			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
+			wantDownstreamCustomSessionData:   expectedHappyOIDCPasswordGrantCustomSession,
+			wantAdditionalClaims: map[string]interface{}{
+				"downstreamCustomClaim": "i am a claim value",
+				"downstreamOtherClaim":  "other claim value",
+			},
+		},
+		{
+			name: "OIDC upstream password grant happy path using GET with additional claim mappings, when upstream claims are not available",
+			idps: oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(passwordGrantUpstreamOIDCIdentityProviderBuilder().
+				WithAdditionalClaimMappings(map[string]string{
+					"downstream": "upstream",
+				}).
+				WithIDTokenClaim("not-upstream", "value").
+				Build()),
+			method:                            http.MethodGet,
+			path:                              happyGetRequestPath,
+			customUsernameHeader:              pointer.String(oidcUpstreamUsername),
+			customPasswordHeader:              pointer.String(oidcUpstreamPassword),
+			wantPasswordGrantCall:             happyUpstreamPasswordGrantMockExpectation,
+			wantStatus:                        http.StatusFound,
+			wantContentType:                   htmlContentType,
+			wantRedirectLocationRegexp:        happyAuthcodeDownstreamRedirectLocationRegexp,
+			wantDownstreamIDTokenSubject:      oidcUpstreamIssuer + "?sub=" + oidcUpstreamSubjectQueryEscaped,
+			wantDownstreamIDTokenUsername:     oidcUpstreamUsername,
+			wantDownstreamIDTokenGroups:       oidcUpstreamGroupMembership,
+			wantDownstreamRequestedScopes:     happyDownstreamScopesRequested,
+			wantDownstreamRedirectURI:         downstreamRedirectURI,
+			wantDownstreamGrantedScopes:       happyDownstreamScopesGranted,
+			wantDownstreamNonce:               downstreamNonce,
+			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
+			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
+			wantDownstreamCustomSessionData:   expectedHappyOIDCPasswordGrantCustomSession,
+			wantAdditionalClaims:              nil, // downstream claims are empty
+		},
 		{
 			name:                              "LDAP cli upstream happy path using GET",
 			idps:                              oidctestutil.NewUpstreamIDPListerBuilder().WithLDAP(&upstreamLDAPIdentityProvider),
@@ -3126,6 +3189,7 @@ func TestAuthorizationEndpoint(t *testing.T) {
 				test.wantDownstreamClientID,
 				test.wantDownstreamRedirectURI,
 				test.wantDownstreamCustomSessionData,
+				test.wantAdditionalClaims,
 			)
 		default:
 			require.Empty(t, rsp.Header().Values("Location"))
@@ -3176,9 +3240,15 @@ func TestAuthorizationEndpoint(t *testing.T) {
 			oidcClientsClient := supervisorClient.ConfigV1alpha1().OIDCClients("some-namespace")
 			oauthHelperWithRealStorage, kubeOauthStore := createOauthHelperWithRealStorage(secretsClient, oidcClientsClient)
 			oauthHelperWithNullStorage, _ := createOauthHelperWithNullStorage(secretsClient, oidcClientsClient)
+
+			idps := test.idps.Build()
+			if len(test.wantAdditionalClaims) > 0 {
+				require.True(t, len(idps.GetOIDCIdentityProviders()) > 0, "wantAdditionalClaims requires at least one OIDC IDP")
+			}
+
 			subject := NewHandler(
 				downstreamIssuer,
-				test.idps.Build(),
+				idps,
 				oauthHelperWithNullStorage, oauthHelperWithRealStorage,
 				test.generateCSRF, test.generatePKCE, test.generateNonce,
 				test.stateEncoder, test.cookieEncoder,

internal/oidc/callback/callback_handler.go

@@ -74,13 +74,15 @@ func NewHandler(
 			return httperr.Wrap(http.StatusUnprocessableEntity, err.Error(), err)
 		}
 
+		additionalClaims := downstreamsession.MapAdditionalClaimsFromUpstreamIDToken(upstreamIDPConfig, token.IDToken.Claims)
+
 		customSessionData, err := downstreamsession.MakeDownstreamOIDCCustomSessionData(upstreamIDPConfig, token, username)
 		if err != nil {
 			return httperr.Wrap(http.StatusUnprocessableEntity, err.Error(), err)
 		}
 
 		openIDSession := downstreamsession.MakeDownstreamSession(subject, username, groups,
-			authorizeRequester.GetGrantedScopes(), authorizeRequester.GetClient().GetID(), customSessionData)
+			authorizeRequester.GetGrantedScopes(), authorizeRequester.GetClient().GetID(), customSessionData, additionalClaims)
 
 		authorizeResponder, err := oauthHelper.NewAuthorizeResponse(r.Context(), authorizeRequester, openIDSession)
 		if err != nil {

internal/oidc/callback/callback_handler_test.go

@@ -189,6 +189,7 @@ func TestCallbackEndpoint(t *testing.T) {
 		wantDownstreamPKCEChallenge       string
 		wantDownstreamPKCEChallengeMethod string
 		wantDownstreamCustomSessionData   *psession.CustomSessionData
+		wantAdditionalClaims              map[string]interface{}
 
 		wantAuthcodeExchangeCall *expectedAuthcodeExchange
 	}{
@@ -223,6 +224,49 @@ func TestCallbackEndpoint(t *testing.T) {
 				args:                    happyExchangeAndValidateTokensArgs,
 			},
 		},
+		{
+			name: "GET with good state and cookie with additional params",
+			idps: oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(happyUpstream().
+				WithAdditionalClaimMappings(map[string]string{
+					"downstreamCustomClaim":  "upstreamCustomClaim",
+					"downstreamOtherClaim":   "upstreamOtherClaim",
+					"downstreamMissingClaim": "upstreamMissingClaim",
+				}).
+				WithIDTokenClaim("upstreamCustomClaim", "i am a claim value").
+				WithIDTokenClaim("upstreamOtherClaim", "other claim value").
+				Build()),
+			method: http.MethodGet,
+			path: newRequestPath().WithState(
+				happyUpstreamStateParam().WithAuthorizeRequestParams(
+					shallowCopyAndModifyQuery(
+						happyDownstreamRequestParamsQuery,
+						map[string]string{"response_mode": "form_post"},
+					).Encode(),
+				).Build(t, happyStateCodec),
+			).String(),
+			csrfCookie:                        happyCSRFCookie,
+			wantStatus:                        http.StatusOK,
+			wantContentType:                   "text/html;charset=UTF-8",
+			wantBodyFormResponseRegexp:        `<code id="manual-auth-code">(.+)</code>`,
+			wantDownstreamIDTokenSubject:      oidcUpstreamIssuer + "?sub=" + oidcUpstreamSubjectQueryEscaped,
+			wantDownstreamIDTokenUsername:     oidcUpstreamUsername,
+			wantDownstreamIDTokenGroups:       oidcUpstreamGroupMembership,
+			wantDownstreamRequestedScopes:     happyDownstreamScopesRequested,
+			wantDownstreamGrantedScopes:       happyDownstreamScopesGranted,
+			wantDownstreamNonce:               downstreamNonce,
+			wantDownstreamClientID:            downstreamPinnipedClientID,
+			wantDownstreamPKCEChallenge:       downstreamPKCEChallenge,
+			wantDownstreamPKCEChallengeMethod: downstreamPKCEChallengeMethod,
+			wantDownstreamCustomSessionData:   happyDownstreamCustomSessionData,
+			wantAuthcodeExchangeCall: &expectedAuthcodeExchange{
+				performedByUpstreamName: happyUpstreamIDPName,
+				args:                    happyExchangeAndValidateTokensArgs,
+			},
+			wantAdditionalClaims: map[string]interface{}{
+				"downstreamCustomClaim": "i am a claim value",
+				"downstreamOtherClaim":  "other claim value",
+			},
+		},
 		{
 			name:                              "GET with good state and cookie and successful upstream token exchange returns 303 to downstream client callback with its state and code",
 			idps:                              oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(happyUpstream().Build()),
@@ -1463,6 +1507,7 @@ func TestCallbackEndpoint(t *testing.T) {
 					test.wantDownstreamClientID,
 					downstreamRedirectURI,
 					test.wantDownstreamCustomSessionData,
+					test.wantAdditionalClaims,
 				)
 
 			// Otherwise, expect an empty response body.
@@ -1490,6 +1535,7 @@ func TestCallbackEndpoint(t *testing.T) {
 					test.wantDownstreamClientID,
 					downstreamRedirectURI,
 					test.wantDownstreamCustomSessionData,
+					test.wantAdditionalClaims,
 				)
 			}
 		})

internal/oidc/discovery/discovery_handler.go

@@ -70,7 +70,7 @@ func NewHandler(issuerURL string) http.Handler {
 		TokenEndpointAuthMethodsSupported: []string{"client_secret_basic"},
 		CodeChallengeMethodsSupported:     []string{"S256"},
 		ScopesSupported:                   []string{oidcapi.ScopeOpenID, oidcapi.ScopeOfflineAccess, oidcapi.ScopeRequestAudience, oidcapi.ScopeUsername, oidcapi.ScopeGroups},
-		ClaimsSupported:                   []string{oidcapi.IDTokenClaimUsername, oidcapi.IDTokenClaimGroups},
+		ClaimsSupported:                   []string{oidcapi.IDTokenClaimUsername, oidcapi.IDTokenClaimGroups, oidcapi.IDTokenClaimAdditionalClaims},
 	}
 
 	var b bytes.Buffer

internal/oidc/discovery/discovery_handler_test.go

@@ -47,7 +47,7 @@ func TestDiscovery(t *testing.T) {
 				"token_endpoint_auth_methods_supported": ["client_secret_basic"],
 				"scopes_supported": ["openid", "offline_access", "pinniped:request-audience", "username", "groups"],
 				"code_challenge_methods_supported": ["S256"],
-				"claims_supported": ["username", "groups"],
+				"claims_supported": ["username", "groups", "additionalClaims"],
 				"discovery.supervisor.pinniped.dev/v1alpha1": {
 					"pinniped_identity_providers_endpoint": "https://some-issuer.com/some/path/v1alpha1/pinniped_identity_providers"
 				}

internal/oidc/downstreamsession/downstream_session.go

@@ -48,6 +48,7 @@ func MakeDownstreamSession(
 	grantedScopes []string,
 	clientID string,
 	custom *psession.CustomSessionData,
+	additionalClaims map[string]interface{},
 ) *psession.PinnipedSession {
 	now := time.Now().UTC()
 	openIDSession := &psession.PinnipedSession{
@@ -72,6 +73,9 @@ func MakeDownstreamSession(
 	if slices.Contains(grantedScopes, oidcapi.ScopeGroups) {
 		extras[oidcapi.IDTokenClaimGroups] = groups
 	}
+	if len(additionalClaims) > 0 {
+		extras[oidcapi.IDTokenClaimAdditionalClaims] = additionalClaims
+	}
 	openIDSession.IDTokenClaims().Extra = extras
 
 	return openIDSession
@@ -212,6 +216,27 @@ func GetDownstreamIdentityFromUpstreamIDToken(
 	return subject, username, groups, err
 }
 
+// MapAdditionalClaimsFromUpstreamIDToken returns the additionalClaims mapped from the upstream token, if any.
+func MapAdditionalClaimsFromUpstreamIDToken(
+	upstreamIDPConfig provider.UpstreamOIDCIdentityProviderI,
+	idTokenClaims map[string]interface{},
+) map[string]interface{} {
+	mapped := make(map[string]interface{}, len(upstreamIDPConfig.GetAdditionalClaimMappings()))
+	for downstreamClaimName, upstreamClaimName := range upstreamIDPConfig.GetAdditionalClaimMappings() {
+		upstreamClaimValue, ok := idTokenClaims[upstreamClaimName]
+		if !ok {
+			plog.Warning(
+				"additionalClaims mapping claim in upstream ID token missing",
+				"upstreamName", upstreamIDPConfig.GetName(),
+				"claimName", upstreamClaimName,
+			)
+		} else {
+			mapped[downstreamClaimName] = upstreamClaimValue
+		}
+	}
+	return mapped
+}
+
 func getSubjectAndUsernameFromUpstreamIDToken(
 	upstreamIDPConfig provider.UpstreamOIDCIdentityProviderI,
 	idTokenClaims map[string]interface{},

internal/oidc/downstreamsession/downstream_session_test.go

@@ -0,0 +1,72 @@
+// Copyright 2020-2022 the Pinniped contributors. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package downstreamsession
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"go.pinniped.dev/internal/testutil/oidctestutil"
+)
+
+func TestMapAdditionalClaimsFromUpstreamIDToken(t *testing.T) {
+	tests := []struct {
+		name                    string
+		additionalClaimMappings map[string]string
+		upstreamClaims          map[string]interface{}
+		wantClaims              map[string]interface{}
+	}{
+		{
+			name: "happy path",
+			additionalClaimMappings: map[string]string{
+				"email": "notification_email",
+			},
+			upstreamClaims: map[string]interface{}{
+				"notification_email": "test@example.com",
+			},
+			wantClaims: map[string]interface{}{
+				"email": "test@example.com",
+			},
+		},
+		{
+			name: "missing",
+			additionalClaimMappings: map[string]string{
+				"email": "email",
+			},
+			upstreamClaims: map[string]interface{}{},
+			wantClaims:     map[string]interface{}{},
+		},
+		{
+			name: "complex",
+			additionalClaimMappings: map[string]string{
+				"complex": "complex",
+			},
+			upstreamClaims: map[string]interface{}{
+				"complex": map[string]string{
+					"subClaim": "subValue",
+				},
+			},
+			wantClaims: map[string]interface{}{
+				"complex": map[string]string{
+					"subClaim": "subValue",
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			idp := oidctestutil.NewTestUpstreamOIDCIdentityProviderBuilder().
+				WithAdditionalClaimMappings(test.additionalClaimMappings).
+				Build()
+			actual := MapAdditionalClaimsFromUpstreamIDToken(idp, test.upstreamClaims)
+
+			require.Equal(t, test.wantClaims, actual)
+		})
+	}
+}

internal/oidc/login/post_login_handler.go

@@ -84,7 +84,7 @@ func NewPostHandler(issuerURL string, upstreamIDPs oidc.UpstreamIdentityProvider
 		groups := authenticateResponse.User.GetGroups()
 		customSessionData := downstreamsession.MakeDownstreamLDAPOrADCustomSessionData(ldapUpstream, idpType, authenticateResponse, username)
 		openIDSession := downstreamsession.MakeDownstreamSession(subject, username, groups,
-			authorizeRequester.GetGrantedScopes(), authorizeRequester.GetClient().GetID(), customSessionData)
+			authorizeRequester.GetGrantedScopes(), authorizeRequester.GetClient().GetID(), customSessionData, map[string]interface{}{})
 		oidc.PerformAuthcodeRedirect(r, w, oauthHelper, authorizeRequester, openIDSession, false)
 
 		return nil

internal/oidc/login/post_login_handler_test.go

@@ -1027,6 +1027,7 @@ func TestPostLoginEndpoint(t *testing.T) {
 					tt.wantDownstreamClient,
 					tt.wantDownstreamRedirectURI,
 					tt.wantDownstreamCustomSessionData,
+					map[string]interface{}{},
 				)
 			case tt.wantRedirectToLoginPageError != "":
 				// Expecting an error redirect to the login UI page.
@@ -1062,6 +1063,7 @@ func TestPostLoginEndpoint(t *testing.T) {
 					tt.wantDownstreamClient,
 					tt.wantDownstreamRedirectURI,
 					tt.wantDownstreamCustomSessionData,
+					map[string]interface{}{},
 				)
 			default:
 				require.Failf(t, "test should have expected a redirect or form body",

internal/oidc/provider/dynamic_upstream_idp_provider.go

@@ -61,6 +61,9 @@ type UpstreamOIDCIdentityProviderI interface {
 	// GetAdditionalAuthcodeParams returns additional params to be sent on authcode requests.
 	GetAdditionalAuthcodeParams() map[string]string
 
+	// GetAdditionalClaimMappings returns additional claims to be mapped from the upstream ID token.
+	GetAdditionalClaimMappings() map[string]string
+
 	// PasswordCredentialsGrantAndValidateTokens performs upstream OIDC resource owner password credentials grant and
 	// token validation. Returns the validated raw tokens as well as the parsed claims of the ID token.
 	PasswordCredentialsGrantAndValidateTokens(ctx context.Context, username, password string) (*oidctypes.Token, error)

internal/oidc/token/token_handler_test.go

@@ -40,6 +40,7 @@ import (
 	v1 "k8s.io/client-go/kubernetes/typed/core/v1"
 
 	configv1alpha1 "go.pinniped.dev/generated/latest/apis/supervisor/config/v1alpha1"
+	oidcapi "go.pinniped.dev/generated/latest/apis/supervisor/oidc"
 	supervisorfake "go.pinniped.dev/generated/latest/client/supervisor/clientset/versioned/fake"
 	"go.pinniped.dev/internal/crud"
 	"go.pinniped.dev/internal/fositestorage/accesstoken"
@@ -285,19 +286,16 @@ type tokenEndpointResponseExpectedValues struct {
 	wantUpstreamOIDCValidateTokenCall *expectedUpstreamValidateTokens
 	wantCustomSessionDataStored       *psession.CustomSessionData
 	wantWarnings                      []RecordedWarning
+	wantAdditionalClaims              map[string]interface{}
 }
 
 type authcodeExchangeInputs struct {
-	modifyAuthRequest  func(authRequest *http.Request)
+	modifyAuthRequest             func(authRequest *http.Request)
-	modifyTokenRequest func(tokenRequest *http.Request, authCode string)
+	modifyTokenRequest            func(tokenRequest *http.Request, authCode string)
-	modifyStorage      func(
+	makeJwksSigningKeyAndProvider MakeJwksSigningKeyAndProviderFunc
-		t *testing.T,
+	customSessionData             *psession.CustomSessionData
-		s fositestoragei.AllFositeStorage,
+	modifySession                 func(*psession.PinnipedSession)
-		authCode string,
+	want                          tokenEndpointResponseExpectedValues
-	)
-	makeOathHelper    OauthHelperFactoryFunc
-	customSessionData *psession.CustomSessionData
-	want              tokenEndpointResponseExpectedValues
 }
 
 func addFullyCapableDynamicClientAndSecretToKubeResources(t *testing.T, supervisorClient *supervisorfake.Clientset, kubeClient *fake.Clientset) {
@@ -344,6 +342,37 @@ func TestTokenEndpointAuthcodeExchange(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "request is valid and tokens are issued with additional claims",
+			authcodeExchange: authcodeExchangeInputs{
+				modifyAuthRequest: func(r *http.Request) { r.Form.Set("scope", "openid profile email username groups") },
+				modifySession: func(session *psession.PinnipedSession) {
+					session.IDTokenClaims().Extra[oidcapi.IDTokenClaimAdditionalClaims] = map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]string{
+							"name": "value",
+						},
+					}
+				},
+				want: tokenEndpointResponseExpectedValues{
+					wantStatus:            http.StatusOK,
+					wantClientID:          pinnipedCLIClientID,
+					wantSuccessBodyFields: []string{"id_token", "access_token", "token_type", "scope", "expires_in"}, // no refresh token
+					wantRequestedScopes:   []string{"openid", "profile", "email", "username", "groups"},
+					wantGrantedScopes:     []string{"openid", "username", "groups"},
+					wantUsername:          goodUsername,
+					wantGroups:            goodGroups,
+					wantAdditionalClaims: map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]interface{}{
+							"name": "value",
+						},
+					},
+				},
+			},
+		},
 		{
 			name:          "request is valid and tokens are issued for dynamic client",
 			kubeResources: addFullyCapableDynamicClientAndSecretToKubeResources,
@@ -364,6 +393,42 @@ func TestTokenEndpointAuthcodeExchange(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:          "request is valid and tokens are issued for dynamic client with additional claims",
+			kubeResources: addFullyCapableDynamicClientAndSecretToKubeResources,
+			authcodeExchange: authcodeExchangeInputs{
+				modifyAuthRequest: func(r *http.Request) {
+					addDynamicClientIDToFormPostBody(r)
+					r.Form.Set("scope", "openid pinniped:request-audience username groups")
+				},
+				modifyTokenRequest: modifyAuthcodeTokenRequestWithDynamicClientAuth,
+				modifySession: func(session *psession.PinnipedSession) {
+					session.IDTokenClaims().Extra[oidcapi.IDTokenClaimAdditionalClaims] = map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]string{
+							"name": "value",
+						},
+					}
+				},
+				want: tokenEndpointResponseExpectedValues{
+					wantStatus:            http.StatusOK,
+					wantClientID:          dynamicClientID,
+					wantSuccessBodyFields: []string{"id_token", "access_token", "token_type", "scope", "expires_in"}, // no refresh token
+					wantRequestedScopes:   []string{"openid", "pinniped:request-audience", "username", "groups"},
+					wantGrantedScopes:     []string{"openid", "pinniped:request-audience", "username", "groups"},
+					wantUsername:          goodUsername,
+					wantGroups:            goodGroups,
+					wantAdditionalClaims: map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]interface{}{
+							"name": "value",
+						},
+					},
+				},
+			},
+		},
 		{
 			name: "openid scope was not requested from authorize endpoint",
 			authcodeExchange: authcodeExchangeInputs{
@@ -788,7 +853,9 @@ func TestTokenEndpointAuthcodeExchange(t *testing.T) {
 		{
 			name: "private signing key for JWTs has not yet been provided by the controller who is responsible for dynamically providing it",
 			authcodeExchange: authcodeExchangeInputs{
-				makeOathHelper: makeOauthHelperWithNilPrivateJWTSigningKey,
+				makeJwksSigningKeyAndProvider: func(t *testing.T, issuer string) (*ecdsa.PrivateKey, jwks.DynamicJWKSProvider) {
+					return nil, jwks.NewDynamicJWKSProvider()
+				},
 				want: tokenEndpointResponseExpectedValues{
 					wantStatus:            http.StatusServiceUnavailable,
 					wantErrorResponseBody: fositeTemporarilyUnavailableErrorBody,
@@ -870,7 +937,7 @@ func TestTokenEndpointWhenAuthcodeIsUsedTwice(t *testing.T) {
 				test.authcodeExchange.want.wantClientID,
 				test.authcodeExchange.want.wantRequestedScopes, test.authcodeExchange.want.wantGrantedScopes,
 				test.authcodeExchange.want.wantUsername, test.authcodeExchange.want.wantGroups,
-				nil, approxRequestTime)
+				nil, test.authcodeExchange.want.wantAdditionalClaims, approxRequestTime)
 
 			// Check that the access token and refresh token storage were both deleted, and the number of other storage objects did not change.
 			testutil.RequireNumberOfSecretsMatchingLabelSelector(t, secrets, labels.Set{crud.SecretLabelKey: authorizationcode.TypeLabelValue}, 1)
@@ -941,6 +1008,41 @@ func TestTokenEndpointTokenExchange(t *testing.T) { // tests for grant_type "urn
 			requestedAudience: "some-workload-cluster",
 			wantStatus:        http.StatusOK,
 		},
+		{
+			name: "happy path with additional claims",
+			authcodeExchange: authcodeExchangeInputs{
+				modifyAuthRequest: func(authRequest *http.Request) {
+					authRequest.Form.Set("scope", "openid pinniped:request-audience username groups")
+				},
+				modifySession: func(session *psession.PinnipedSession) {
+					session.IDTokenClaims().Extra[oidcapi.IDTokenClaimAdditionalClaims] = map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]string{
+							"name": "value",
+						},
+					}
+				},
+				want: tokenEndpointResponseExpectedValues{
+					wantStatus:            http.StatusOK,
+					wantClientID:          pinnipedCLIClientID,
+					wantSuccessBodyFields: []string{"id_token", "access_token", "token_type", "expires_in", "scope"},
+					wantRequestedScopes:   []string{"openid", "pinniped:request-audience", "username", "groups"},
+					wantGrantedScopes:     []string{"openid", "pinniped:request-audience", "username", "groups"},
+					wantUsername:          goodUsername,
+					wantGroups:            goodGroups,
+					wantAdditionalClaims: map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]interface{}{
+							"name": "value",
+						},
+					},
+				},
+			},
+			requestedAudience: "some-workload-cluster",
+			wantStatus:        http.StatusOK,
+		},
 		{
 			name: "happy path without requesting username and groups scopes",
 			authcodeExchange: authcodeExchangeInputs{
@@ -973,6 +1075,50 @@ func TestTokenEndpointTokenExchange(t *testing.T) { // tests for grant_type "urn
 			requestedAudience: "some-workload-cluster",
 			wantStatus:        http.StatusOK,
 		},
+		{
+			name:          "happy path with dynamic client and additional claims",
+			kubeResources: addFullyCapableDynamicClientAndSecretToKubeResources,
+			authcodeExchange: authcodeExchangeInputs{
+				modifyAuthRequest: func(authRequest *http.Request) {
+					addDynamicClientIDToFormPostBody(authRequest)
+					authRequest.Form.Set("scope", "openid pinniped:request-audience username groups")
+				},
+				modifySession: func(session *psession.PinnipedSession) {
+					session.IDTokenClaims().Extra[oidcapi.IDTokenClaimAdditionalClaims] = map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]string{
+							"name": "value",
+						},
+					}
+				},
+				modifyTokenRequest: modifyAuthcodeTokenRequestWithDynamicClientAuth,
+				want: tokenEndpointResponseExpectedValues{
+					wantStatus:            http.StatusOK,
+					wantClientID:          dynamicClientID,
+					wantSuccessBodyFields: []string{"id_token", "access_token", "token_type", "expires_in", "scope"},
+					wantRequestedScopes:   []string{"openid", "pinniped:request-audience", "username", "groups"},
+					wantGrantedScopes:     []string{"openid", "pinniped:request-audience", "username", "groups"},
+					wantUsername:          goodUsername,
+					wantGroups:            goodGroups,
+					wantAdditionalClaims: map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]interface{}{
+							"name": "value",
+						},
+					},
+				},
+			},
+			modifyRequestParams: func(t *testing.T, params url.Values) {
+				params.Del("client_id") // client auth for dynamic clients must be in basic auth header
+			},
+			modifyRequestHeaders: func(r *http.Request) {
+				r.SetBasicAuth(dynamicClientID, testutil.PlaintextPassword1)
+			},
+			requestedAudience: "some-workload-cluster",
+			wantStatus:        http.StatusOK,
+		},
 		{
 			name:          "happy path with dynamic client without requesting groups, so gets no groups in ID tokens",
 			kubeResources: addFullyCapableDynamicClientAndSecretToKubeResources,
@@ -1389,8 +1535,11 @@ func TestTokenEndpointTokenExchange(t *testing.T) { // tests for grant_type "urn
 					authRequest.Form.Set("scope", "openid pinniped:request-audience username groups")
 				},
 				// Fail to fetch a JWK signing key after the authcode exchange has happened.
-				makeOathHelper: makeOauthHelperWithJWTKeyThatWorksOnlyOnce,
+				makeJwksSigningKeyAndProvider: func(t *testing.T, issuer string) (*ecdsa.PrivateKey, jwks.DynamicJWKSProvider) {
-				want:           successfulAuthCodeExchange,
+					jwtSigningKey, jwkProvider := generateJWTSigningKeyAndJWKSProvider(t, goodIssuer)
+					return jwtSigningKey, &singleUseJWKProvider{DynamicJWKSProvider: jwkProvider}
+				},
+				want: successfulAuthCodeExchange,
 			},
 			requestedAudience:     "some-workload-cluster",
 			wantStatus:            http.StatusServiceUnavailable,
@@ -1481,6 +1630,9 @@ func TestTokenEndpointTokenExchange(t *testing.T) { // tests for grant_type "urn
 			if test.authcodeExchange.want.wantGroups != nil {
 				idTokenFields = append(idTokenFields, "groups")
 			}
+			if len(test.authcodeExchange.want.wantAdditionalClaims) > 0 {
+				idTokenFields = append(idTokenFields, oidcapi.IDTokenClaimAdditionalClaims)
+			}
 			require.ElementsMatch(t, idTokenFields, getMapKeys(tokenClaims))
 
 			// Assert that the returned token has expected claims values.
@@ -1505,11 +1657,22 @@ func TestTokenEndpointTokenExchange(t *testing.T) { // tests for grant_type "urn
 				require.Nil(t, tokenClaims["groups"])
 			}
 
+			if len(test.authcodeExchange.want.wantAdditionalClaims) > 0 {
+				require.Equal(t, test.authcodeExchange.want.wantAdditionalClaims, tokenClaims[oidcapi.IDTokenClaimAdditionalClaims])
+			}
+			additionalClaims, ok := tokenClaims[oidcapi.IDTokenClaimAdditionalClaims].(map[string]interface{})
+			if ok && tokenClaims[oidcapi.IDTokenClaimAdditionalClaims] != nil {
+				require.True(t, len(additionalClaims) > 0, "additionalClaims may never be present and empty in the id token")
+			}
+
 			// Also assert that some are the same as the original downstream ID token.
 			requireClaimsAreEqual(t, "iss", claimsOfFirstIDToken, tokenClaims)       // issuer
 			requireClaimsAreEqual(t, "sub", claimsOfFirstIDToken, tokenClaims)       // subject
 			requireClaimsAreEqual(t, "rat", claimsOfFirstIDToken, tokenClaims)       // requested at
 			requireClaimsAreEqual(t, "auth_time", claimsOfFirstIDToken, tokenClaims) // auth time
+			if len(test.authcodeExchange.want.wantAdditionalClaims) > 0 {
+				requireClaimsAreEqual(t, oidcapi.IDTokenClaimAdditionalClaims, claimsOfFirstIDToken, tokenClaims)
+			}
 
 			// Also assert which are the different from the original downstream ID token.
 			requireClaimsAreNotEqual(t, "jti", claimsOfFirstIDToken, tokenClaims) // JWT ID
@@ -1691,6 +1854,12 @@ func TestRefreshGrant(t *testing.T) {
 		return want
 	}
 
+	happyRefreshTokenResponseForOpenIDAndOfflineAccessWithAdditionalClaims := func(wantCustomSessionDataStored *psession.CustomSessionData, expectToValidateToken *oauth2.Token, wantAdditionalClaims map[string]interface{}) tokenEndpointResponseExpectedValues {
+		want := happyRefreshTokenResponseForOpenIDAndOfflineAccess(wantCustomSessionDataStored, expectToValidateToken)
+		want.wantAdditionalClaims = wantAdditionalClaims
+		return want
+	}
+
 	happyRefreshTokenResponseForLDAP := func(wantCustomSessionDataStored *psession.CustomSessionData) tokenEndpointResponseExpectedValues {
 		want := happyAuthcodeExchangeTokenResponseForOpenIDAndOfflineAccess(wantCustomSessionDataStored)
 		want.wantUpstreamRefreshCall = happyLDAPUpstreamRefreshCall()
@@ -1783,6 +1952,60 @@ func TestRefreshGrant(t *testing.T) {
 				),
 			},
 		},
+		{
+			name: "happy path refresh grant with openid scope granted (id token returned) and additionalClaims",
+			idps: oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(
+				upstreamOIDCIdentityProviderBuilder().WithValidatedAndMergedWithUserInfoTokens(&oidctypes.Token{
+					IDToken: &oidctypes.IDToken{
+						Claims: map[string]interface{}{
+							"sub": goodUpstreamSubject,
+						},
+					},
+				}).WithRefreshedTokens(refreshedUpstreamTokensWithIDAndRefreshTokens()).Build()),
+			authcodeExchange: authcodeExchangeInputs{
+				customSessionData: initialUpstreamOIDCRefreshTokenCustomSessionData(),
+				modifyAuthRequest: func(r *http.Request) { r.Form.Set("scope", "openid offline_access username groups") },
+				modifySession: func(session *psession.PinnipedSession) {
+					session.IDTokenClaims().Extra[oidcapi.IDTokenClaimAdditionalClaims] = map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]string{
+							"name": "value",
+						},
+					}
+				},
+				want: tokenEndpointResponseExpectedValues{
+					wantStatus:                  http.StatusOK,
+					wantClientID:                pinnipedCLIClientID,
+					wantSuccessBodyFields:       []string{"id_token", "refresh_token", "access_token", "token_type", "expires_in", "scope"},
+					wantRequestedScopes:         []string{"openid", "offline_access", "username", "groups"},
+					wantGrantedScopes:           []string{"openid", "offline_access", "username", "groups"},
+					wantCustomSessionDataStored: initialUpstreamOIDCRefreshTokenCustomSessionData(),
+					wantUsername:                goodUsername,
+					wantGroups:                  goodGroups,
+					wantAdditionalClaims: map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]interface{}{
+							"name": "value",
+						},
+					},
+				},
+			},
+			refreshRequest: refreshRequestInputs{
+				want: happyRefreshTokenResponseForOpenIDAndOfflineAccessWithAdditionalClaims(
+					upstreamOIDCCustomSessionDataWithNewRefreshToken(oidcUpstreamRefreshedRefreshToken),
+					refreshedUpstreamTokensWithIDAndRefreshTokens(),
+					map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]interface{}{
+							"name": "value",
+						},
+					},
+				),
+			},
+		},
 		{
 			name: "happy path refresh grant with openid scope granted (id token returned) using dynamic client",
 			idps: oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(
@@ -1811,6 +2034,66 @@ func TestRefreshGrant(t *testing.T) {
 				)),
 			},
 		},
+		{
+			name: "happy path refresh grant with openid scope granted (id token returned) using dynamic client with additional claims",
+			idps: oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(
+				upstreamOIDCIdentityProviderBuilder().WithValidatedAndMergedWithUserInfoTokens(&oidctypes.Token{
+					IDToken: &oidctypes.IDToken{
+						Claims: map[string]interface{}{
+							"sub": goodUpstreamSubject,
+						},
+					},
+				}).WithRefreshedTokens(refreshedUpstreamTokensWithIDAndRefreshTokens()).Build()),
+			kubeResources: addFullyCapableDynamicClientAndSecretToKubeResources,
+			authcodeExchange: authcodeExchangeInputs{
+				customSessionData: initialUpstreamOIDCRefreshTokenCustomSessionData(),
+				modifyAuthRequest: func(r *http.Request) {
+					addDynamicClientIDToFormPostBody(r)
+					r.Form.Set("scope", "openid offline_access username groups")
+				},
+				modifySession: func(session *psession.PinnipedSession) {
+					session.IDTokenClaims().Extra[oidcapi.IDTokenClaimAdditionalClaims] = map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]string{
+							"name": "value",
+						},
+					}
+				},
+				modifyTokenRequest: modifyAuthcodeTokenRequestWithDynamicClientAuth,
+				want: tokenEndpointResponseExpectedValues{
+					wantStatus:                  http.StatusOK,
+					wantClientID:                dynamicClientID,
+					wantSuccessBodyFields:       []string{"id_token", "refresh_token", "access_token", "token_type", "expires_in", "scope"},
+					wantRequestedScopes:         []string{"openid", "offline_access", "username", "groups"},
+					wantGrantedScopes:           []string{"openid", "offline_access", "username", "groups"},
+					wantCustomSessionDataStored: initialUpstreamOIDCRefreshTokenCustomSessionData(),
+					wantUsername:                goodUsername,
+					wantGroups:                  goodGroups,
+					wantAdditionalClaims: map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]interface{}{
+							"name": "value",
+						},
+					},
+				},
+			},
+			refreshRequest: refreshRequestInputs{
+				modifyTokenRequest: modifyRefreshTokenRequestWithDynamicClientAuth,
+				want: withWantDynamicClientID(happyRefreshTokenResponseForOpenIDAndOfflineAccessWithAdditionalClaims(
+					upstreamOIDCCustomSessionDataWithNewRefreshToken(oidcUpstreamRefreshedRefreshToken),
+					refreshedUpstreamTokensWithIDAndRefreshTokens(),
+					map[string]interface{}{
+						"upstreamString": "string value",
+						"upstreamFloat":  42.0,
+						"upstreamObj": map[string]interface{}{
+							"name": "value",
+						},
+					},
+				)),
+			},
+		},
 		{
 			name: "happy path refresh grant with upstream username claim but without downstream username scope granted, using dynamic client",
 			idps: oidctestutil.NewUpstreamIDPListerBuilder().WithOIDC(
@@ -3852,16 +4135,13 @@ func exchangeAuthcodeForTokens(
 	var oauthHelper fosite.OAuth2Provider
 	// Use lower minimum required bcrypt cost than we would use in production to keep unit the tests fast.
 	oauthStore = oidc.NewKubeStorage(secrets, oidcClientsClient, oidc.DefaultOIDCTimeoutsConfiguration(), bcrypt.MinCost)
-	if test.makeOathHelper != nil {
+
-		oauthHelper, authCode, jwtSigningKey = test.makeOathHelper(t, authRequest, oauthStore, test.customSessionData)
+	if test.makeJwksSigningKeyAndProvider == nil {
-	} else {
+		test.makeJwksSigningKeyAndProvider = generateJWTSigningKeyAndJWKSProvider
-		// Note that makeHappyOauthHelper() calls simulateAuthEndpointHavingAlreadyRun() to preload the session storage.
-		oauthHelper, authCode, jwtSigningKey = makeHappyOauthHelper(t, authRequest, oauthStore, test.customSessionData)
 	}
 
-	if test.modifyStorage != nil {
+	// Note that makeHappyOauthHelper() calls simulateAuthEndpointHavingAlreadyRun() to preload the session storage.
-		test.modifyStorage(t, oauthStore, authCode)
+	oauthHelper, authCode, jwtSigningKey = makeHappyOauthHelper(t, authRequest, oauthStore, test.makeJwksSigningKeyAndProvider, test.customSessionData, test.modifySession)
-	}
 
 	subject = NewHandler(idps, oauthHelper)
 
@@ -3936,10 +4216,10 @@ func requireTokenEndpointBehavior(
 		wantRefreshToken := contains(test.wantSuccessBodyFields, "refresh_token")
 
 		requireInvalidAuthCodeStorage(t, authCode, oauthStore, secrets, requestTime)
-		requireValidAccessTokenStorage(t, parsedResponseBody, oauthStore, test.wantClientID, test.wantRequestedScopes, test.wantGrantedScopes, test.wantUsername, test.wantGroups, test.wantCustomSessionDataStored, secrets, requestTime)
+		requireValidAccessTokenStorage(t, parsedResponseBody, oauthStore, test.wantClientID, test.wantRequestedScopes, test.wantGrantedScopes, test.wantUsername, test.wantGroups, test.wantCustomSessionDataStored, test.wantAdditionalClaims, secrets, requestTime)
 		requireInvalidPKCEStorage(t, authCode, oauthStore)
 		// Performing a refresh does not update the OIDC storage, so after a refresh it should still have the old custom session data and old username and groups from the initial login.
-		requireValidOIDCStorage(t, parsedResponseBody, authCode, oauthStore, test.wantClientID, test.wantRequestedScopes, test.wantGrantedScopes, oldUsername, oldGroups, oldCustomSessionData, requestTime)
+		requireValidOIDCStorage(t, parsedResponseBody, authCode, oauthStore, test.wantClientID, test.wantRequestedScopes, test.wantGrantedScopes, oldUsername, oldGroups, oldCustomSessionData, test.wantAdditionalClaims, requestTime)
 
 		expectedNumberOfRefreshTokenSessionsStored := 0
 		if wantRefreshToken {
@@ -3948,10 +4228,10 @@ func requireTokenEndpointBehavior(
 		expectedNumberOfIDSessionsStored := 0
 		if wantIDToken {
 			expectedNumberOfIDSessionsStored = 1
-			requireValidIDToken(t, parsedResponseBody, jwtSigningKey, test.wantClientID, wantNonceValueInIDToken, test.wantUsername, test.wantGroups, parsedResponseBody["access_token"].(string), requestTime)
+			requireValidIDToken(t, parsedResponseBody, jwtSigningKey, test.wantClientID, wantNonceValueInIDToken, test.wantUsername, test.wantGroups, test.wantAdditionalClaims, parsedResponseBody["access_token"].(string), requestTime)
 		}
 		if wantRefreshToken {
-			requireValidRefreshTokenStorage(t, parsedResponseBody, oauthStore, test.wantClientID, test.wantRequestedScopes, test.wantGrantedScopes, test.wantUsername, test.wantGroups, test.wantCustomSessionDataStored, secrets, requestTime)
+			requireValidRefreshTokenStorage(t, parsedResponseBody, oauthStore, test.wantClientID, test.wantRequestedScopes, test.wantGrantedScopes, test.wantUsername, test.wantGroups, test.wantCustomSessionDataStored, test.wantAdditionalClaims, secrets, requestTime)
 		}
 
 		testutil.RequireNumberOfSecretsMatchingLabelSelector(t, secrets, labels.Set{crud.SecretLabelKey: authorizationcode.TypeLabelValue}, 1)
@@ -4053,24 +4333,21 @@ func getFositeDataSignature(t *testing.T, data string) string {
 	return split[1]
 }
 
-type OauthHelperFactoryFunc func(
+type MakeJwksSigningKeyAndProviderFunc func(t *testing.T, issuer string) (*ecdsa.PrivateKey, jwks.DynamicJWKSProvider)
-	t *testing.T,
-	authRequest *http.Request,
-	store fositestoragei.AllFositeStorage,
-	initialCustomSessionData *psession.CustomSessionData,
-) (fosite.OAuth2Provider, string, *ecdsa.PrivateKey)
 
 func makeHappyOauthHelper(
 	t *testing.T,
 	authRequest *http.Request,
 	store fositestoragei.AllFositeStorage,
+	makeJwksSigningKeyAndProvider MakeJwksSigningKeyAndProviderFunc,
 	initialCustomSessionData *psession.CustomSessionData,
+	modifySession func(session *psession.PinnipedSession),
 ) (fosite.OAuth2Provider, string, *ecdsa.PrivateKey) {
 	t.Helper()
 
-	jwtSigningKey, jwkProvider := generateJWTSigningKeyAndJWKSProvider(t, goodIssuer)
+	jwtSigningKey, jwkProvider := makeJwksSigningKeyAndProvider(t, goodIssuer)
 	oauthHelper := oidc.FositeOauth2Helper(store, goodIssuer, hmacSecretFunc, jwkProvider, oidc.DefaultOIDCTimeoutsConfiguration())
-	authResponder := simulateAuthEndpointHavingAlreadyRun(t, authRequest, oauthHelper, initialCustomSessionData)
+	authResponder := simulateAuthEndpointHavingAlreadyRun(t, authRequest, oauthHelper, initialCustomSessionData, modifySession)
 	return oauthHelper, authResponder.GetCode(), jwtSigningKey
 }
 
@@ -4087,40 +4364,13 @@ func (s *singleUseJWKProvider) GetJWKS(issuerName string) (jwks *jose.JSONWebKey
 	return s.DynamicJWKSProvider.GetJWKS(issuerName)
 }
 
-func makeOauthHelperWithJWTKeyThatWorksOnlyOnce(
-	t *testing.T,
-	authRequest *http.Request,
-	store fositestoragei.AllFositeStorage,
-	initialCustomSessionData *psession.CustomSessionData,
-) (fosite.OAuth2Provider, string, *ecdsa.PrivateKey) {
-	t.Helper()
-
-	jwtSigningKey, jwkProvider := generateJWTSigningKeyAndJWKSProvider(t, goodIssuer)
-	oauthHelper := oidc.FositeOauth2Helper(store, goodIssuer, hmacSecretFunc, &singleUseJWKProvider{DynamicJWKSProvider: jwkProvider}, oidc.DefaultOIDCTimeoutsConfiguration())
-	authResponder := simulateAuthEndpointHavingAlreadyRun(t, authRequest, oauthHelper, initialCustomSessionData)
-	return oauthHelper, authResponder.GetCode(), jwtSigningKey
-}
-
-func makeOauthHelperWithNilPrivateJWTSigningKey(
-	t *testing.T,
-	authRequest *http.Request,
-	store fositestoragei.AllFositeStorage,
-	initialCustomSessionData *psession.CustomSessionData,
-) (fosite.OAuth2Provider, string, *ecdsa.PrivateKey) {
-	t.Helper()
-
-	jwkProvider := jwks.NewDynamicJWKSProvider() // empty provider which contains no signing key for this issuer
-	oauthHelper := oidc.FositeOauth2Helper(store, goodIssuer, hmacSecretFunc, jwkProvider, oidc.DefaultOIDCTimeoutsConfiguration())
-	authResponder := simulateAuthEndpointHavingAlreadyRun(t, authRequest, oauthHelper, initialCustomSessionData)
-	return oauthHelper, authResponder.GetCode(), nil
-}
-
 // Simulate the auth endpoint running so Fosite code will fill the store with realistic values.
 func simulateAuthEndpointHavingAlreadyRun(
 	t *testing.T,
 	authRequest *http.Request,
 	oauthHelper fosite.OAuth2Provider,
 	initialCustomSessionData *psession.CustomSessionData,
+	modifySession func(session *psession.PinnipedSession),
 ) fosite.AuthorizeResponder {
 	// We only set the fields in the session that Fosite wants us to set.
 	ctx := context.Background()
@@ -4137,6 +4387,10 @@ func simulateAuthEndpointHavingAlreadyRun(
 		},
 		Custom: initialCustomSessionData,
 	}
+	if modifySession != nil {
+		modifySession(session)
+	}
+
 	authRequester, err := oauthHelper.NewAuthorizeRequest(ctx, authRequest)
 	require.NoError(t, err)
 	if strings.Contains(authRequest.Form.Get("scope"), "openid") {
@@ -4212,6 +4466,7 @@ func requireValidRefreshTokenStorage(
 	wantUsername string,
 	wantGroups []string,
 	wantCustomSessionData *psession.CustomSessionData,
+	wantAdditionalClaims map[string]interface{},
 	secrets v1.SecretInterface,
 	requestTime time.Time,
 ) {
@@ -4241,6 +4496,7 @@ func requireValidRefreshTokenStorage(
 		wantUsername,
 		wantGroups,
 		wantCustomSessionData,
+		wantAdditionalClaims,
 		requestTime,
 	)
 
@@ -4257,6 +4513,7 @@ func requireValidAccessTokenStorage(
 	wantUsername string,
 	wantGroups []string,
 	wantCustomSessionData *psession.CustomSessionData,
+	wantAdditionalClaims map[string]interface{},
 	secrets v1.SecretInterface,
 	requestTime time.Time,
 ) {
@@ -4305,6 +4562,7 @@ func requireValidAccessTokenStorage(
 		wantUsername,
 		wantGroups,
 		wantCustomSessionData,
+		wantAdditionalClaims,
 		requestTime,
 	)
 
@@ -4351,6 +4609,7 @@ func requireValidOIDCStorage(
 	wantUsername string,
 	wantGroups []string,
 	wantCustomSessionData *psession.CustomSessionData,
+	wantAdditionalClaims map[string]interface{},
 	requestTime time.Time,
 ) {
 	t.Helper()
@@ -4378,6 +4637,7 @@ func requireValidOIDCStorage(
 			wantUsername,
 			wantGroups,
 			wantCustomSessionData,
+			wantAdditionalClaims,
 			requestTime,
 		)
 	} else {
@@ -4397,6 +4657,7 @@ func requireValidStoredRequest(
 	wantUsername string,
 	wantGroups []string,
 	wantCustomSessionData *psession.CustomSessionData,
+	wantAdditionalClaims map[string]interface{},
 	requestTime time.Time,
 ) {
 	t.Helper()
@@ -4429,6 +4690,9 @@ func requireValidStoredRequest(
 		expectedExtra["groups"] = toSliceOfInterface(wantGroups)
 	}
 	expectedExtra["azp"] = wantClientID
+	if len(wantAdditionalClaims) > 0 {
+		expectedExtra[oidcapi.IDTokenClaimAdditionalClaims] = wantAdditionalClaims
+	}
 	require.Equal(t, expectedExtra, claims.Extra)
 
 	// We are in charge of setting these fields. For the purpose of testing, we ensure that the
@@ -4518,6 +4782,7 @@ func requireValidIDToken(
 	wantNonceValueInIDToken bool,
 	wantUsernameInIDToken string,
 	wantGroupsInIDToken []string,
+	wantAdditionalClaims map[string]interface{},
 	actualAccessToken string,
 	requestTime time.Time,
 ) {
@@ -4532,18 +4797,19 @@ func requireValidIDToken(
 	token := oidctestutil.VerifyECDSAIDToken(t, goodIssuer, wantClientID, jwtSigningKey, idTokenString)
 
 	var claims struct {
-		Subject         string   `json:"sub"`
+		Subject          string                 `json:"sub"`
-		Audience        []string `json:"aud"`
+		Audience         []string               `json:"aud"`
-		Issuer          string   `json:"iss"`
+		Issuer           string                 `json:"iss"`
-		JTI             string   `json:"jti"`
+		JTI              string                 `json:"jti"`
-		Nonce           string   `json:"nonce"`
+		Nonce            string                 `json:"nonce"`
-		AccessTokenHash string   `json:"at_hash"`
+		AccessTokenHash  string                 `json:"at_hash"`
-		ExpiresAt       int64    `json:"exp"`
+		ExpiresAt        int64                  `json:"exp"`
-		IssuedAt        int64    `json:"iat"`
+		IssuedAt         int64                  `json:"iat"`
-		RequestedAt     int64    `json:"rat"`
+		RequestedAt      int64                  `json:"rat"`
-		AuthTime        int64    `json:"auth_time"`
+		AuthTime         int64                  `json:"auth_time"`
-		Groups          []string `json:"groups"`
+		Groups           []string               `json:"groups"`
-		Username        string   `json:"username"`
+		Username         string                 `json:"username"`
+		AdditionalClaims map[string]interface{} `json:"additionalClaims"`
 	}
 
 	idTokenFields := []string{"sub", "aud", "iss", "jti", "auth_time", "exp", "iat", "rat", "azp", "at_hash"}
@@ -4556,6 +4822,9 @@ func requireValidIDToken(
 	if wantGroupsInIDToken != nil {
 		idTokenFields = append(idTokenFields, "groups")
 	}
+	if len(wantAdditionalClaims) > 0 {
+		idTokenFields = append(idTokenFields, oidcapi.IDTokenClaimAdditionalClaims)
+	}
 
 	// make sure that these are the only fields in the token
 	var m map[string]interface{}
@@ -4573,6 +4842,8 @@ func requireValidIDToken(
 	require.Equal(t, wantClientID, m["azp"])
 	require.Equal(t, goodIssuer, claims.Issuer)
 	require.NotEmpty(t, claims.JTI)
+	require.Equal(t, wantAdditionalClaims, claims.AdditionalClaims)
+	require.NotEqual(t, map[string]interface{}{}, claims.AdditionalClaims, "additionalClaims may never be present and empty in the id token")
 
 	if wantNonceValueInIDToken {
 		require.Equal(t, goodNonce, claims.Nonce)

internal/testutil/oidctestutil/oidctestutil.go

@@ -28,6 +28,7 @@ import (
 	kubetesting "k8s.io/client-go/testing"
 	"k8s.io/utils/strings/slices"
 
+	oidcapi "go.pinniped.dev/generated/latest/apis/supervisor/oidc"
 	"go.pinniped.dev/internal/authenticators"
 	"go.pinniped.dev/internal/crud"
 	"go.pinniped.dev/internal/fositestorage/authorizationcode"
@@ -164,6 +165,7 @@ type TestUpstreamOIDCIdentityProvider struct {
 	GroupsClaim              string
 	Scopes                   []string
 	AdditionalAuthcodeParams map[string]string
+	AdditionalClaimMappings  map[string]string
 	AllowPasswordGrant       bool
 
 	ExchangeAuthcodeAndValidateTokensFunc func(
@@ -207,6 +209,10 @@ func (u *TestUpstreamOIDCIdentityProvider) GetAdditionalAuthcodeParams() map[str
 	return u.AdditionalAuthcodeParams
 }
 
+func (u *TestUpstreamOIDCIdentityProvider) GetAdditionalClaimMappings() map[string]string {
+	return u.AdditionalClaimMappings
+}
+
 func (u *TestUpstreamOIDCIdentityProvider) GetName() string {
 	return u.Name
 }
@@ -630,6 +636,7 @@ type TestUpstreamOIDCIdentityProviderBuilder struct {
 	authorizationURL                     url.URL
 	hasUserInfoURL                       bool
 	additionalAuthcodeParams             map[string]string
+	additionalClaimMappings              map[string]string
 	allowPasswordGrant                   bool
 	authcodeExchangeErr                  error
 	passwordGrantErr                     error
@@ -716,6 +723,11 @@ func (u *TestUpstreamOIDCIdentityProviderBuilder) WithAdditionalAuthcodeParams(p
 	return u
 }
 
+func (u *TestUpstreamOIDCIdentityProviderBuilder) WithAdditionalClaimMappings(m map[string]string) *TestUpstreamOIDCIdentityProviderBuilder {
+	u.additionalClaimMappings = m
+	return u
+}
+
 func (u *TestUpstreamOIDCIdentityProviderBuilder) WithRefreshToken(token string) *TestUpstreamOIDCIdentityProviderBuilder {
 	u.refreshToken = &oidctypes.RefreshToken{Token: token}
 	return u
@@ -792,6 +804,7 @@ func (u *TestUpstreamOIDCIdentityProviderBuilder) Build() *TestUpstreamOIDCIdent
 		AuthorizationURL:         u.authorizationURL,
 		UserInfoURL:              u.hasUserInfoURL,
 		AdditionalAuthcodeParams: u.additionalAuthcodeParams,
+		AdditionalClaimMappings:  u.additionalClaimMappings,
 		ExchangeAuthcodeAndValidateTokensFunc: func(ctx context.Context, authcode string, pkceCodeVerifier pkce.Code, expectedIDTokenNonce nonce.Nonce) (*oidctypes.Token, error) {
 			if u.authcodeExchangeErr != nil {
 				return nil, u.authcodeExchangeErr
@@ -934,6 +947,7 @@ func RequireAuthCodeRegexpMatch(
 	wantDownstreamClientID string,
 	wantDownstreamRedirectURI string,
 	wantCustomSessionData *psession.CustomSessionData,
+	wantAdditionalClaims map[string]interface{},
 ) {
 	t.Helper()
 
@@ -972,6 +986,7 @@ func RequireAuthCodeRegexpMatch(
 		wantDownstreamClientID,
 		wantDownstreamRedirectURI,
 		wantCustomSessionData,
+		wantAdditionalClaims,
 	)
 
 	// One PKCE should have been stored.
@@ -1011,6 +1026,7 @@ func includesOpenIDScope(scopes []string) bool {
 	return false
 }
 
+//nolint:funlen
 func validateAuthcodeStorage(
 	t *testing.T,
 	oauthStore fositestoragei.AllFositeStorage,
@@ -1023,6 +1039,7 @@ func validateAuthcodeStorage(
 	wantDownstreamClientID string,
 	wantDownstreamRedirectURI string,
 	wantCustomSessionData *psession.CustomSessionData,
+	wantAdditionalClaims map[string]interface{},
 ) (*fosite.Request, *psession.PinnipedSession) {
 	t.Helper()
 
@@ -1066,6 +1083,10 @@ func validateAuthcodeStorage(
 	require.Equal(t, wantDownstreamClientID, actualClaims.Extra["azp"])
 	wantDownstreamIDTokenExtraClaimsCount := 1 // should always have azp claim
 
+	if len(wantAdditionalClaims) > 0 {
+		wantDownstreamIDTokenExtraClaimsCount++
+	}
+
 	// Check the user's identity, which are put into the downstream ID token's subject, username and groups claims.
 	require.Equal(t, wantDownstreamIDTokenSubject, actualClaims.Subject)
 	if wantDownstreamIDTokenUsername == "" {
@@ -1085,6 +1106,14 @@ func validateAuthcodeStorage(
 		actualDownstreamIDTokenGroups := actualClaims.Extra["groups"]
 		require.Nil(t, actualDownstreamIDTokenGroups)
 	}
+	if len(wantAdditionalClaims) > 0 {
+		actualAdditionalClaims, ok := actualClaims.Get(oidcapi.IDTokenClaimAdditionalClaims).(map[string]interface{})
+		require.True(t, ok, "expected %s to be a map[string]interface{}", oidcapi.IDTokenClaimAdditionalClaims)
+		require.Equal(t, wantAdditionalClaims, actualAdditionalClaims)
+	} else {
+		require.NotContains(t, actualClaims.Extra, oidcapi.IDTokenClaimAdditionalClaims, "%s must not be present when there are no wanted additional claims", oidcapi.IDTokenClaimAdditionalClaims)
+	}
+
 	// Make sure that we asserted on every extra claim.
 	require.Len(t, actualClaims.Extra, wantDownstreamIDTokenExtraClaimsCount)
 

internal/upstreamoidc/upstreamoidc.go

@@ -43,6 +43,7 @@ type ProviderConfig struct {
 	Client                   *http.Client
 	AllowPasswordGrant       bool
 	AdditionalAuthcodeParams map[string]string
+	AdditionalClaimMappings  map[string]string
 	RevocationURL            *url.URL // will commonly be nil: many providers do not offer this
 	Provider                 interface {
 		Verifier(*coreosoidc.Config) *coreosoidc.IDTokenVerifier
@@ -78,6 +79,10 @@ func (p *ProviderConfig) GetAdditionalAuthcodeParams() map[string]string {
 	return p.AdditionalAuthcodeParams
 }
 
+func (p *ProviderConfig) GetAdditionalClaimMappings() map[string]string {
+	return p.AdditionalClaimMappings
+}
+
 func (p *ProviderConfig) GetName() string {
 	return p.Name
 }

internal/upstreamoidc/upstreamoidc_test.go

@@ -68,6 +68,16 @@ func TestProviderConfig(t *testing.T) {
 			rawClaims: []byte(`{`),
 		}
 		require.False(t, p.HasUserInfoURL())
+
+		// AdditionalAuthcodeParams defaults to empty
+		require.Empty(t, p.AdditionalAuthcodeParams)
+		p.AdditionalAuthcodeParams = map[string]string{"additional": "authcodeParams"}
+		require.Equal(t, p.GetAdditionalAuthcodeParams(), map[string]string{"additional": "authcodeParams"})
+
+		// AdditionalClaimMappings defaults to empty
+		require.Empty(t, p.AdditionalClaimMappings)
+		p.AdditionalClaimMappings = map[string]string{"additional": "claimMappings"}
+		require.Equal(t, p.GetAdditionalClaimMappings(), map[string]string{"additional": "claimMappings"})
 	})
 
 	const (

test/integration/supervisor_discovery_test.go

@@ -505,7 +505,7 @@ func requireWellKnownEndpointIsWorking(t *testing.T, supervisorScheme, superviso
       "response_types_supported": ["code"],
       "response_modes_supported": ["query", "form_post"],
       "code_challenge_methods_supported": ["S256"],
-      "claims_supported": ["username", "groups"],
+      "claims_supported": ["username", "groups", "additionalClaims"],
       "discovery.supervisor.pinniped.dev/v1alpha1": {"pinniped_identity_providers_endpoint": "%s/v1alpha1/pinniped_identity_providers"},
       "subject_types_supported": ["public"],
       "id_token_signing_alg_values_supported": ["ES256"]