1 files changed, 130 insertions, 0 deletions
diff --git a/src/feature/hs/hs_cache.h b/src/feature/hs/hs_cache.h
new file mode 100644
index 0000000000..1e479700fa
--- /dev/null
+++ b/src/feature/hs/hs_cache.h
@@ -0,0 +1,130 @@
+/* Copyright (c) 2016-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file hs_cache.h
+ * \brief Header file for hs_cache.c
+ **/
+
+#ifndef TOR_HS_CACHE_H
+#define TOR_HS_CACHE_H
+
+#include <stdint.h>
+
+#include "or/hs_common.h"
+#include "or/hs_descriptor.h"
+#include "or/rendcommon.h"
+#include "or/torcert.h"
+
+struct ed25519_public_key_t;
+
+/* This is the maximum time an introduction point state object can stay in the
+ * client cache in seconds (2 mins or 120 seconds). */
+#define HS_CACHE_CLIENT_INTRO_STATE_MAX_AGE (2 * 60)
+
+/* Introduction point state. */
+typedef struct hs_cache_intro_state_t {
+  /* When this entry was created and put in the cache. */
+  time_t created_ts;
+
+  /* Did it suffered a generic error? */
+  unsigned int error : 1;
+
+  /* Did it timed out? */
+  unsigned int timed_out : 1;
+
+  /* How many times we tried to reached it and it was unreachable. */
+  uint32_t unreachable_count;
+} hs_cache_intro_state_t;
+
+typedef struct hs_cache_client_intro_state_t {
+  /* Contains hs_cache_intro_state_t object indexed by introduction point
+   * authentication key. */
+  digest256map_t *intro_points;
+} hs_cache_client_intro_state_t;
+
+/* Descriptor representation on the directory side which is a subset of
+ * information that the HSDir can decode and serve it. */
+typedef struct hs_cache_dir_descriptor_t {
+  /* This object is indexed using the blinded pubkey located in the plaintext
+   * data which is populated only once the descriptor has been successfully
+   * decoded and validated. This simply points to that pubkey. */
+  const uint8_t *key;
+
+  /* When does this entry has been created. Used to expire entries. */
+  time_t created_ts;
+
+  /* Descriptor plaintext information. Obviously, we can't decrypt the
+   * encrypted part of the descriptor. */
+  hs_desc_plaintext_data_t *plaintext_data;
+
+  /* Encoded descriptor which is basically in text form. It's a NUL terminated
+   * string thus safe to strlen(). */
+  char *encoded_desc;
+} hs_cache_dir_descriptor_t;
+
+/* Public API */
+
+void hs_cache_init(void);
+void hs_cache_free_all(void);
+void hs_cache_clean_as_dir(time_t now);
+size_t hs_cache_handle_oom(time_t now, size_t min_remove_bytes);
+
+unsigned int hs_cache_get_max_descriptor_size(void);
+
+/* Store and Lookup function. They are version agnostic that is depending on
+ * the requested version of the descriptor, it will be re-routed to the
+ * right function. */
+int hs_cache_store_as_dir(const char *desc);
+int hs_cache_lookup_as_dir(uint32_t version, const char *query,
+                           const char **desc_out);
+
+const hs_descriptor_t *
+hs_cache_lookup_as_client(const struct ed25519_public_key_t *key);
+const char *
+hs_cache_lookup_encoded_as_client(const struct ed25519_public_key_t *key);
+int hs_cache_store_as_client(const char *desc_str,
+                             const struct ed25519_public_key_t *identity_pk);
+void hs_cache_clean_as_client(time_t now);
+void hs_cache_purge_as_client(void);
+
+/* Client failure cache. */
+void hs_cache_client_intro_state_note(
+                              const struct ed25519_public_key_t *service_pk,
+                              const struct ed25519_public_key_t *auth_key,
+                              rend_intro_point_failure_t failure);
+const hs_cache_intro_state_t *hs_cache_client_intro_state_find(
+                              const struct ed25519_public_key_t *service_pk,
+                              const struct ed25519_public_key_t *auth_key);
+void hs_cache_client_intro_state_clean(time_t now);
+void hs_cache_client_intro_state_purge(void);
+
+#ifdef HS_CACHE_PRIVATE
+#include "lib/crypt_ops/crypto_ed25519.h"
+
+/** Represents a locally cached HS descriptor on a hidden service client. */
+typedef struct hs_cache_client_descriptor_t {
+  /* This object is indexed using the service identity public key */
+  struct ed25519_public_key_t key;
+
+  /* When will this entry expire? We expire cached client descriptors in the
+   * start of the next time period, since that's when clients need to start
+   * using the next blinded key of the service. */
+  time_t expiration_ts;
+
+  /* The cached descriptor, this object is the owner. It can't be NULL. A
+   * cache object without a valid descriptor is not possible. */
+  hs_descriptor_t *desc;
+
+  /* Encoded descriptor in string form. Can't be NULL. */
+  char *encoded_desc;
+} hs_cache_client_descriptor_t;
+
+STATIC size_t cache_clean_v3_as_dir(time_t now, time_t global_cutoff);
+
+STATIC hs_cache_client_descriptor_t *
+lookup_v3_desc_as_client(const uint8_t *key);
+
+#endif /* defined(HS_CACHE_PRIVATE) */
+
+#endif /* !defined(TOR_HS_CACHE_H) */