adds rest api to download ca cert

api/pkg/apis/v1alpha1/managers/margo/device.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"math/rand/v2"
+	"os"
 	"strings"
 	"time"
 
@@ -692,3 +693,13 @@ func (s *DeviceManager) GetDeviceClientUsingId(ctx context.Context, clientId str
 
 	return device, nil
 }
+
+func (s *DeviceManager) GetServerCA(ctx context.Context) ([]byte, error) {
+	// review: this function is not suitable for DeviceManager, it should be kept separately as settings in the vendor itself
+	serverCAPath, exists := s.Config.Properties["serverCAPath"]
+	if !exists || serverCAPath == "" {
+		return nil, fmt.Errorf("serverCAPath property is empty in the config")
+	}
+
+	return os.ReadFile(serverCAPath)
+}

api/pkg/apis/v1alpha1/vendors/margo/device-agent-vendor.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/sha256"
+	"encoding/base64"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -148,6 +149,13 @@ func (self *DeviceAgentVendor) GetEndpoints() []v1alpha2.Endpoint {
 			Handler:    self.onDeploymentStatusUpdate,
 			Parameters: []string{"clientId?", "deploymentId?"},
 		},
+		{
+			Methods:    []string{fasthttp.MethodGet},
+			Route:      route + "/onboarding/certificate",
+			Version:    self.Version,
+			Handler:    self.downloadServerCA,
+			Parameters: []string{},
+		},
 	}
 }
 
@@ -905,6 +913,28 @@ func (self *DeviceAgentVendor) verifyRequestSignature(ctx context.Context, clien
 	return true, nil
 }
 
+func (self *DeviceAgentVendor) downloadServerCA(request v1alpha2.COARequest) v1alpha2.COAResponse {
+	pCtx, span := observability.StartSpan("Margo Device Vendor",
+		request.Context,
+		&map[string]string{
+			"method": "downloadServerCA",
+			"route":  request.Route,
+			"verb":   request.Method,
+		})
+	defer span.End()
+	deviceVendorLogger.InfofCtx(pCtx, "V (MargoDeviceVendor): downloadServerCA, method: %s", request.Method)
+
+	ca, err := self.DeviceManager.GetServerCA(pCtx)
+	if err != nil {
+		return createErrorResponse2(deviceVendorLogger, span, fmt.Errorf("Unable to find Server CA"), "Server CA download failed", v1alpha2.InternalError)
+	}
+	return v1alpha2.COAResponse{
+		State:       v1alpha2.OK,
+		Body:        []byte(`{"certificate": "` + base64.RawURLEncoding.EncodeToString(ca) + `"}`),
+		ContentType: "application/json",
+	}
+}
+
 // Create a utility function for consistent header parsing
 func ParseRequestHeaders(ctx context.Context) (map[string]string, error) {
 	headers := make(map[string]string)

api/symphony-api-margo.json

@@ -741,7 +741,8 @@
             "type": "managers.margo.device",
             "properties": {
               "providers.persistentstate": "redis-state",
-              "singleton": "true"              
+              "singleton": "true",
+              "serverCAPath": "./certificates/ca-cert.pem"             
             },
            "providers": {
               "redis-state": {