Implement simulation mode for cookies (de/en)cryption

This should close #102

This commit can be useful for two use-cases:

1. When deploying Snuffleupagus on big CMS like Magento, and not knowing
   what cookies are modified via javascript.
2. When deploying Snuffleupagus on big websites: you don't want to disconnect
   every single user at once.

When simulation is enabled, if the decryption fails, a log message is
now issued, and the cookie value taken as it (since odds are that it's
non-encrypted).

1 files changed, 1 insertions, 0 deletions

diff --git a/src/sp_config_keywords.c b/src/sp_config_keywords.c
index 2d294ee..32363b8 100644
--- a/src/sp_config_keywords.c
+++ b/src/sp_config_keywords.c
@@ -111,6 +111,7 @@ int parse_cookie(char *line) {
   sp_config_functions sp_config_funcs_cookie_encryption[] = {
       {parse_str, SP_TOKEN_NAME, &name},
       {parse_str, SP_TOKEN_SAMESITE, &samesite},
+      {parse_empty, SP_TOKEN_SIMULATION, &cookie->simulation},
       {parse_empty, SP_TOKEN_ENCRYPT, &cookie->encrypt},
       {0}};