fix(authn): make hashing/encryption keys used to secure cookies (#2536)

fix(authn): configurable hashing/encryption keys used to secure cookies

If they are not configured zot will generate a random hashing key at startup,
invalidating all cookies if zot is restarted. closes: #2526

Signed-off-by: Petu Eusebiu <peusebiu@cisco.com>

pkg/api/config/config.go

@@ -67,12 +67,15 @@ type AuthHTPasswd struct {
 }
 
 type AuthConfig struct {
-	FailDelay int
-	HTPasswd  AuthHTPasswd
-	LDAP      *LDAPConfig
-	Bearer    *BearerConfig
-	OpenID    *OpenIDConfig
-	APIKey    bool
+	FailDelay         int
+	HTPasswd          AuthHTPasswd
+	LDAP              *LDAPConfig
+	Bearer            *BearerConfig
+	OpenID            *OpenIDConfig
+	APIKey            bool
+	SessionKeysFile   string
+	SessionHashKey    []byte `json:"-"`
+	SessionEncryptKey []byte `json:"-"`
 }
 
 type BearerConfig struct {
@@ -81,6 +84,11 @@ type BearerConfig struct {
 	Cert    string
 }
 
+type SessionKeys struct {
+	HashKey    string
+	EncryptKey string `mapstructure:",omitempty"`
+}
+
 type OpenIDConfig struct {
 	Providers map[string]OpenIDProviderConfig
 }