feat(cache): implement hashed API key storage and retrieval

Adds a new hashed key storage mechanism for API keys in the cache. 
Replaces direct mapping to API keys with composite keys based on 
organizationId and name. Implements searching of API keys using 
hash comparisons for improved security. Updates related tests to 
ensure correct functionality and validate the hashing. Also, 
adds support for a new dependency `golang.org/x/crypto`.

cache/cache.go

@@ -14,7 +14,7 @@ import (
 type Cache struct {
 	organizations map[string]domain.Organization
 	users         map[string][]string
-	apiKeys       map[string]domain.APIKey
+	apiKeys       map[string]domain.APIKey // keyed by organizationId-name
 	services      map[string]map[string]map[string]struct{}
 	subGraphs     map[string]string
 	lastUpdate    map[string]string
@@ -22,15 +22,17 @@ type Cache struct {
 }
 
 func (c *Cache) OrganizationByAPIKey(apiKey string) *domain.Organization {
-	key, exists := c.apiKeys[apiKey]
-	if !exists {
-		return nil
+	// Find the API key by comparing hashes
+	for _, key := range c.apiKeys {
+		if hash.CompareAPIKey(key.Key, apiKey) {
+			org, exists := c.organizations[key.OrganizationId]
+			if !exists {
+				return nil
+			}
+			return &org
+		}
 	}
-	org, exists := c.organizations[key.OrganizationId]
-	if !exists {
-		return nil
-	}
-	return &org
+	return nil
 }
 
 func (c *Cache) OrganizationsByUser(sub string) []domain.Organization {
@@ -43,11 +45,13 @@ func (c *Cache) OrganizationsByUser(sub string) []domain.Organization {
 }
 
 func (c *Cache) ApiKeyByKey(key string) *domain.APIKey {
-	k, exists := c.apiKeys[hash.String(key)]
-	if !exists {
-		return nil
+	// Find the API key by comparing hashes
+	for _, apiKey := range c.apiKeys {
+		if hash.CompareAPIKey(apiKey.Key, key) {
+			return &apiKey
+		}
 	}
-	return &k
+	return nil
 }
 
 func (c *Cache) Services(orgId, ref, lastUpdate string) ([]string, string) {
@@ -76,14 +80,15 @@ func (c *Cache) Update(msg any, _ goamqp.Headers) (any, error) {
 		key := domain.APIKey{
 			Name:           m.Name,
 			OrganizationId: m.OrganizationId,
-			Key:            m.Key,
+			Key:            m.Key, // This is now the hashed key
 			Refs:           m.Refs,
 			Read:           m.Read,
 			Publish:        m.Publish,
 			CreatedBy:      m.Initiator,
 			CreatedAt:      m.When(),
 		}
-		c.apiKeys[m.Key] = key
+		// Use composite key: organizationId-name
+		c.apiKeys[apiKeyId(m.OrganizationId, m.Name)] = key
 		org := c.organizations[m.OrganizationId]
 		org.APIKeys = append(org.APIKeys, key)
 		c.organizations[m.OrganizationId] = org
@@ -93,7 +98,8 @@ func (c *Cache) Update(msg any, _ goamqp.Headers) (any, error) {
 		c.organizations[m.ID.String()] = *m
 		c.addUser(m.CreatedBy, *m)
 		for _, k := range m.APIKeys {
-			c.apiKeys[k.Key] = k
+			// Use composite key: organizationId-name
+			c.apiKeys[apiKeyId(k.OrganizationId, k.Name)] = k
 		}
 	case *domain.SubGraph:
 		c.updateSubGraph(m.OrganizationId, m.Ref, m.ID.String(), m.Service, m.ChangedAt)
@@ -143,3 +149,7 @@ func refKey(orgId string, ref string) string {
 func subGraphKey(orgId string, ref string, service string) string {
 	return fmt.Sprintf("%s<->%s<->%s", orgId, ref, service)
 }
+
+func apiKeyId(orgId string, name string) string {
+	return fmt.Sprintf("%s<->%s", orgId, name)
+}