B: Dynamically get Auth Secret

service/controllers/controllers.go

@@ -35,6 +35,5 @@ func BuildRouter(r *gin.Engine) {
 	pcoClientMap = make(map[primitive.ObjectID]*pco.PcoApiClient)
 
 	pco := r.Group("/pco")
-	pco.Use(ValidatePcoWebhook)
+	pco.POST("/:userid", ValidatePcoWebhook, ConsumePcoWebhook)
-	pco.POST("/:userid", ConsumePcoWebhook)
 }

service/controllers/pco_auth_middleware.go

@@ -1,22 +1,21 @@
 package controllers
 
 import (
+	"bytes"
 	"context"
 	"crypto/hmac"
 	"crypto/sha256"
 	"encoding/hex"
 	"io"
 
-	"git.preston-baxter.com/Preston_PLB/capstone/frontend-service/config"
+	"git.preston-baxter.com/Preston_PLB/capstone/webhook-service/vendors/pco/webhooks"
-	"git.preston-baxter.com/Preston_PLB/capstone/frontend-service/db/models"
 	"github.com/gin-gonic/gin"
+	"github.com/google/jsonapi"
 )
 
 const PCO_VALIDATE_HEADER = "X-PCO-Webhooks-Authenticity"
 
 func ValidatePcoWebhook(c *gin.Context) {
-	conf := config.Config()
-
 	//get remote version from header
 	remoteDigestStr := c.GetHeader(PCO_VALIDATE_HEADER)
 	if remoteDigestStr == "" {
@@ -26,18 +25,28 @@ func ValidatePcoWebhook(c *gin.Context) {
 	}
 	pcoSig := make([]byte, len(remoteDigestStr)/2)
 	_, err := hex.Decode(pcoSig, []byte(remoteDigestStr))
+	if err != nil {
+		log.WithError(err).Error("Failed to decode byte digest")
+		_ = c.AbortWithError(501, err)
+		return
+	}
 
 	//clone request to harmlessly inspect the body
 	bodyReader := c.Request.Clone(context.Background()).Body
 	body, err := io.ReadAll(bodyReader)
 	if err != nil {
 		log.WithError(err).Error("Failed to read body while validating PCO webhook")
-		c.AbortWithError(501, err)
+		_ = c.AbortWithError(501, err)
 		return
 	}
 
 	//Get secret
-	key := conf.Vendors[models.PCO_VENDOR_NAME].WebhookSecret
+	key, err := getAuthSecret(c, body)
+	if err != nil {
+		log.WithError(err).Error("Failed to find auth secret for event. It may not be setup")
+		_ = c.AbortWithError(501, err)
+		return
+	}
 
 	//Get HMAC
 	hmacSig := hmac.New(sha256.New, []byte(key))
@@ -48,3 +57,20 @@ func ValidatePcoWebhook(c *gin.Context) {
 		c.AbortWithStatus(401)
 	}
 }
+
+func getAuthSecret(c *gin.Context, body []byte) (string, error) {
+	userObjectId := userIdFromContext(c)
+
+	event := &webhooks.EventDelivery{}
+	err := jsonapi.UnmarshalPayload(bytes.NewBuffer(body), event)
+	if err != nil {
+		return "", err
+	}
+
+	webhook, err := mongo.FindPcoSubscriptionForUser(*userObjectId, event.Name)
+	if err != nil {
+		return "", err
+	}
+
+	return webhook.Details.AuthenticitySecret, nil
+}

service/controllers/pco_webhook.go

@@ -28,34 +28,47 @@ var (
 
 type actionFunc func(*gin.Context, *webhooks.EventDelivery) error
 
+func userIdFromContext(c *gin.Context) (*primitive.ObjectID) {
+	if id, ok := c.Get("user_bson_id"); !ok {
+		userId := c.Param("userid")
+
+		if userId == "" {
+			log.Warn("Webhook did not contain user id. Rejecting")
+			c.AbortWithStatus(404)
+			return nil
+		}
+
+		userObjectId, err := primitive.ObjectIDFromHex(userId)
+		if err != nil {
+			log.WithError(err).Warn("User Id was malformed")
+			c.AbortWithStatus(400)
+			return nil
+		}
+		c.Set("user_bson_id", userObjectId)
+		return &userObjectId
+	} else {
+		if objId, ok := id.(primitive.ObjectID); ok {
+			return &objId
+		} else {
+			return nil
+		}
+	}
+}
+
 func ConsumePcoWebhook(c *gin.Context) {
-	userId := c.Param("userid")
+	userObjectId := userIdFromContext(c)
-
-	if userId == "" {
-		log.Warn("Webhook did not contain user id. Rejecting")
-		c.AbortWithStatus(404)
-		return
-	}
-
-	//get actions for user
-	userObjectId, err := primitive.ObjectIDFromHex(userId)
-	if err != nil {
-		log.WithError(err).Warn("User Id was malformed")
-		c.AbortWithStatus(400)
-		return
-	}
-	c.Set("user_bson_id", userObjectId)
 
 	//read body and handle io in parallel because IO shenanigains
 	wg := new(sync.WaitGroup)
 	wg.Add(2)
 
+	//get actions for user
 	var actionMappings []models.ActionMapping
 	var webhookBody *webhooks.EventDelivery
 	errs := make([]error, 2)
 
 	go func(wg *sync.WaitGroup) {
-		actionMappings, errs[0] = mongo.FindActionMappingsByUser(userObjectId)
+		actionMappings, errs[0] = mongo.FindActionMappingsByUser(*userObjectId)
 		wg.Done()
 	}(wg)
 
@@ -81,7 +94,7 @@ func ConsumePcoWebhook(c *gin.Context) {
 			actionKey := fmt.Sprintf("%s:%s", mapping.Action.VendorName, mapping.Action.Type)
 			//if function exists run the function
 			if action, ok := actionFuncMap[actionKey]; ok {
-				err = action(c, webhookBody)
+				err := action(c, webhookBody)
 				//handle error
 				if err != nil {
 					log.WithError(err).Errorf("Failed to execute action: %s. From event source: %s:%s", actionKey, mapping.SourceEvent.VendorName, mapping.SourceEvent.Key)