Add RequireFipsCryptography support for PS256 auth (#224)

* legacy auth is still working at the moment, use new if using broker service or the unseen feature flag is on

Author: ChristopherHX

protocol/task_agent.go

@@ -116,7 +116,13 @@ type TaskAgents struct {
 func (taskAgent *TaskAgent) Authorize(c *http.Client, key interface{}) (*VssOAuthTokenResponse, error) {
 	tokenresp := &VssOAuthTokenResponse{}
 	now := time.Now().UTC().Add(-30 * time.Second)
-	token2 := jwt.NewWithClaims(jwt.SigningMethodRS256, jwt.StandardClaims{
+	var method jwt.SigningMethod = jwt.SigningMethodRS256
+	requireFipsCryptography, hasRequireFipsCryptography := taskAgent.Properties.LookupBool("RequireFipsCryptography")
+	serverV2URL, _ := taskAgent.Properties.LookupString("ServerUrlV2")
+	if requireFipsCryptography && hasRequireFipsCryptography || serverV2URL != "" {
+		method = jwt.SigningMethodPS256
+	}
+	token2 := jwt.NewWithClaims(method, jwt.StandardClaims{
 		Subject:   taskAgent.Authorization.ClientID,
 		Issuer:    taskAgent.Authorization.ClientID,
 		Id:        uuid.New().String(),

runnerconfiguration/compat/actions_runner_compat.go

@@ -45,8 +45,9 @@ type DotnetCredentials struct {
 }
 
 type DotnetCredentialsData struct {
-	ClientID         string `json:"ClientId"`
-	AuthorizationURL string `json:"AuthorizationUrl"`
+	ClientID                string `json:"ClientId"`
+	AuthorizationURL        string `json:"AuthorizationUrl"`
+	RequireFipsCryptography bool   `json:"RequireFipsCryptography"`
 }
 
 func BytesToBigInt(bytes []byte) *big.Int {
@@ -159,6 +160,12 @@ func ToRunnerInstance(fileAccess ConfigFileAccess) (*runnerconfiguration.RunnerI
 			Value: agent.UseV2Flow,
 		}
 	}
+	if credentials.Data.RequireFipsCryptography {
+		props["RequireFipsCryptography"] = protocol.PropertyValue{
+			Type:  "System.Boolean",
+			Value: credentials.Data.RequireFipsCryptography,
+		}
+	}
 
 	return &runnerconfiguration.RunnerInstance{
 		PoolID: poolID,
@@ -208,11 +215,15 @@ func FromRunnerInstance(instance *runnerconfiguration.RunnerInstance, fileAccess
 	if agent.WorkFolder == "" {
 		agent.WorkFolder = "_work"
 	}
+	requireFipsCryptography, hasRequireFipsCryptography := instance.Agent.Properties.LookupBool("RequireFipsCryptography")
 	credentials := &DotnetCredentials{
 		Scheme: "OAuth",
 		Data: DotnetCredentialsData{
 			ClientID:         instance.Agent.Authorization.ClientID,
 			AuthorizationURL: instance.Agent.Authorization.AuthorizationURL,
+			// serverV2URL != "" means recent GitHub Server that requires recent actions/runner
+			// that has received this bugfix https://github.com/actions/runner/pull/3789
+			RequireFipsCryptography: requireFipsCryptography && hasRequireFipsCryptography || serverV2URL != "",
 		},
 	}
 	if err := fileAccess.Write(".runner", agent); err != nil {