Support session encryption

Implement session encryption.

1 files changed, 159 insertions, 0 deletions

diff --git a/src/sp_session.c b/src/sp_session.c
new file mode 100644
index 0000000..4085007
--- /dev/null
+++ b/src/sp_session.c
@@ -0,0 +1,159 @@
+#include "php_snuffleupagus.h"
+#include "ext/session/php_session.h"
+
+ZEND_DECLARE_MODULE_GLOBALS(snuffleupagus);
+
+#ifdef ZTS
+static ts_rsrc_id session_globals_id = 0;
+#define SESSION_G(v) ZEND_TSRMG(session_globals_id, php_ps_globals *, v)
+#ifdef COMPILE_DL_SESSION
+ZEND_TSRMLS_CACHE_EXTERN();
+#endif
+#else
+#define SESSION_G(v) (ps_globals.v)
+#endif
+
+static php_ps_globals *session_globals = NULL;
+static ps_module *s_module;
+static ps_module *s_original_mod;
+static int (*old_s_read)(PS_READ_ARGS);
+static int (*old_s_write)(PS_WRITE_ARGS);
+static int (*previous_sessionRINIT)(INIT_FUNC_ARGS) = NULL;
+static ZEND_INI_MH((*old_OnUpdateSaveHandler)) = NULL;
+
+
+static int sp_hook_s_read(PS_READ_ARGS) {
+  int r = old_s_read(mod_data, key, val, maxlifetime);
+  if (r == SUCCESS && SNUFFLEUPAGUS_G(config).config_session->encrypt &&
+      val != NULL && *val != NULL && ZSTR_LEN(*val)) {
+    zend_string *orig_val = *val;
+    zval val_zval;
+    ZVAL_PSTRINGL(&val_zval, ZSTR_VAL(*val), ZSTR_LEN(*val));
+
+    int ret = decrypt_zval(
+        &val_zval, SNUFFLEUPAGUS_G(config).config_session->simulation,
+        NULL);
+    if (0 != ret) {
+      if (SNUFFLEUPAGUS_G(config).config_session->simulation) {
+        return ret;
+      } else {
+        sp_terminate();
+      }
+    }
+
+    *val = zend_string_dup(val_zval.value.str, 0);
+    if (*val == NULL) {
+      *val = ZSTR_EMPTY_ALLOC();
+    }
+    zend_string_release(orig_val);
+  }
+
+  return r;
+}
+
+
+static int sp_hook_s_write(PS_WRITE_ARGS) {
+  if (ZSTR_LEN(val) > 0 &&
+      SNUFFLEUPAGUS_G(config).config_session->encrypt) {
+    zend_string *new_val = encrypt_zval(ZSTR_VAL(val), ZSTR_LEN(val));
+    return old_s_write(mod_data, key, new_val, maxlifetime);
+  }
+  return old_s_write(mod_data, key, val, maxlifetime);
+}
+
+static void sp_hook_session_module() {
+  ps_module *old_mod = SESSION_G(mod);
+  ps_module *mod;
+
+  if (old_mod == NULL || s_module == old_mod) {
+    return;
+  }
+
+  if (s_module == NULL) {
+    s_module = mod = malloc(sizeof(ps_module));
+    if (mod == NULL) {
+      return;
+    }
+  }
+
+  s_original_mod = old_mod;
+
+  mod = s_module;
+  memcpy(mod, old_mod, sizeof(ps_module));
+
+  old_s_read = mod->s_read;
+  mod->s_read = sp_hook_s_read;
+
+  old_s_write = mod->s_write;
+  mod->s_write = sp_hook_s_write;
+
+  SESSION_G(mod) = mod;
+}
+
+static PHP_INI_MH(sp_OnUpdateSaveHandler) {
+  if (stage == PHP_INI_STAGE_RUNTIME &&
+      SESSION_G(session_status) == php_session_none &&
+      s_original_mod &&
+      zend_string_equals_literal(new_value, "user") == 0 &&
+      strcmp(((ps_module *)s_original_mod)->s_name, "user") ==
+          0) {
+    return SUCCESS;
+  }
+
+  SESSION_G(mod) = s_original_mod;
+
+  int r = old_OnUpdateSaveHandler(entry, new_value, mh_arg1, mh_arg2, mh_arg3,
+                                  stage);
+
+  sp_hook_session_module();
+
+  return r;
+}
+
+static int sp_hook_session_RINIT(INIT_FUNC_ARGS) {
+  if (SESSION_G(mod) == NULL) {
+    zend_ini_entry *ini_entry;
+    if ((ini_entry = zend_hash_str_find_ptr(
+             EG(ini_directives), ZEND_STRL("session.save_handler")))) {
+      if (ini_entry->value) {
+        sp_OnUpdateSaveHandler(NULL, ini_entry->value, NULL, NULL, NULL, 0);
+      }
+    }
+  }
+  return previous_sessionRINIT(INIT_FUNC_ARGS_PASSTHRU);
+}
+
+void hook_session() {
+  zend_module_entry *module;
+
+  if ((module = zend_hash_str_find_ptr(&module_registry,
+                                       ZEND_STRL("session"))) == NULL) {
+    return;
+  }
+
+#ifdef ZTS
+  if (session_globals_id == 0) {
+    session_globals_id = *module->globals_id_ptr;
+  }
+#else
+  if (session_globals == NULL) {
+    session_globals = module->globals_ptr;
+  }
+#endif
+  if (old_OnUpdateSaveHandler != NULL) {
+    return;
+  }
+
+  previous_sessionRINIT = module->request_startup_func;
+  module->request_startup_func = sp_hook_session_RINIT;
+
+  zend_ini_entry *ini_entry;
+  if ((ini_entry = zend_hash_str_find_ptr(
+           EG(ini_directives), ZEND_STRL("session.save_handler"))) != NULL) {
+    old_OnUpdateSaveHandler = ini_entry->on_modify;
+    ini_entry->on_modify = sp_OnUpdateSaveHandler;
+  }
+  s_module = NULL;
+
+  sp_hook_session_module();
+}
\ No newline at end of file