Merge moderation portion of new groupchats codebase

CMakeLists.txt

@@ -229,19 +229,25 @@ set(toxcore_SOURCES ${toxcore_SOURCES}
   toxcore/friend_requests.c
   toxcore/friend_requests.h)
 
-# LAYER 6: Tox messenger
+# LAYER 6: DHT based group chats
+# ----------------------------------------
+set(toxcore_SOURCES ${toxcore_SOURCES}
+  toxcore/group_moderation.c
+  toxcore/group_moderation.h)
+
+# LAYER 7: Tox messenger
 # ----------------------
 set(toxcore_SOURCES ${toxcore_SOURCES}
   toxcore/Messenger.c
   toxcore/Messenger.h)
 
-# LAYER 7: Group chats
+# LAYER 8: Conferences
 # --------------------
 set(toxcore_SOURCES ${toxcore_SOURCES}
   toxcore/group.c
   toxcore/group.h)
 
-# LAYER 8: Public API
+# LAYER 9: Public API
 # -------------------
 set(toxcore_SOURCES ${toxcore_SOURCES}
   toxcore/tox_api.c
@@ -250,7 +256,7 @@ set(toxcore_SOURCES ${toxcore_SOURCES}
   toxcore/tox_private.h)
 set(toxcore_API_HEADERS ${toxcore_API_HEADERS} ${toxcore_SOURCE_DIR}/toxcore/tox.h^tox)
 
-# LAYER 9: New async events API
+# LAYER 10: New async events API
 # -------------------
 set(toxcore_SOURCES ${toxcore_SOURCES}
   toxcore/events/conference_connected.c
@@ -288,7 +294,7 @@ set(toxcore_API_HEADERS ${toxcore_API_HEADERS} ${toxcore_SOURCE_DIR}/toxcore/tox
 set(toxcore_LINK_MODULES ${toxcore_LINK_MODULES} ${MSGPACK_LIBRARIES})
 set(toxcore_PKGCONFIG_REQUIRES ${toxcore_PKGCONFIG_REQUIRES} msgpack)
 
-# LAYER 10: Dispatch recorded events to callbacks.
+# LAYER 11: Dispatch recorded events to callbacks.
 # -------------------
 set(toxcore_SOURCES ${toxcore_SOURCES}
   toxcore/tox_dispatch.c

toxcore/BUILD.bazel

@@ -1,4 +1,5 @@
 load("@rules_cc//cc:defs.bzl", "cc_test")
+load("@rules_fuzzing//fuzzing:cc_defs.bzl", "cc_fuzz_test")
 load("//tools:no_undefined.bzl", "cc_library")
 
 package(features = ["layering_check"])
@@ -51,6 +52,7 @@ cc_library(
     visibility = ["//c-toxcore:__subpackages__"],
     deps = [
         ":ccompat",
+        "//c-toxcore/testing/fuzzing:fuzz_adapter",
         "@libsodium",
     ],
 )
@@ -121,6 +123,7 @@ cc_library(
     ],
     deps = [
         ":ccompat",
+        "//c-toxcore/testing/fuzzing:fuzz_adapter",
         "@pthread",
     ],
 )
@@ -148,6 +151,7 @@ cc_library(
     ],
     deps = [
         ":attributes",
+        ":ccompat",
         ":crypto_core",
         "@pthread",
     ],
@@ -169,6 +173,7 @@ cc_library(
         ":logger",
         ":mono_time",
         ":util",
+        "//c-toxcore/testing/fuzzing:fuzz_adapter",
         "@libsodium",
         "@psocket",
         "@pthread",
@@ -461,6 +466,41 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "group_moderation",
+    srcs = ["group_moderation.c"],
+    hdrs = ["group_moderation.h"],
+    deps = [
+        ":DHT",
+        ":ccompat",
+        ":crypto_core",
+        ":logger",
+        ":mono_time",
+        ":network",
+        ":util",
+        "@libsodium",
+    ],
+)
+
+cc_test(
+    name = "group_moderation_test",
+    size = "small",
+    srcs = ["group_moderation_test.cc"],
+    deps = [
+        ":crypto_core",
+        ":group_moderation",
+        "@com_google_googletest//:gtest",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
+cc_fuzz_test(
+    name = "group_moderation_fuzz_test",
+    srcs = ["group_moderation_fuzz_test.cc"],
+    corpus = ["//tools/toktok-fuzzer/corpus:group_moderation_fuzz_test"],
+    deps = [":group_moderation"],
+)
+
 cc_library(
     name = "Messenger",
     srcs = ["Messenger.c"],

toxcore/DHT.c

@@ -1800,7 +1800,7 @@ static uint8_t do_ping_and_sendnode_requests(DHT *dht, uint64_t *lastgetnode, co
     }
 
     if (num_nodes > 0 && (mono_time_is_timeout(dht->mono_time, *lastgetnode, GET_NODE_INTERVAL)
-                             || *bootstrap_times < MAX_BOOTSTRAP_TIMES)) {
+                          || *bootstrap_times < MAX_BOOTSTRAP_TIMES)) {
         uint32_t rand_node = random_range_u32(num_nodes);
 
         if ((num_nodes - 1) != rand_node) {
@@ -1855,8 +1855,8 @@ static void do_Close(DHT *dht)
     dht->num_to_bootstrap = 0;
 
     const uint8_t not_killed = do_ping_and_sendnode_requests(
-                             dht, &dht->close_lastgetnodes, dht->self_public_key, dht->close_clientlist, LCLIENT_LIST, &dht->close_bootstrap_times,
-                             false);
+                                   dht, &dht->close_lastgetnodes, dht->self_public_key, dht->close_clientlist, LCLIENT_LIST, &dht->close_bootstrap_times,
+                                   false);
 
     if (not_killed != 0) {
         return;
@@ -2568,7 +2568,8 @@ static int handle_LANdiscovery(void *object, const IP_Port *source, const uint8_
 
 /*----------------------------------------------------------------------------------*/
 
-DHT *new_dht(const Logger *log, Mono_Time *mono_time, Networking_Core *net, bool hole_punching_enabled, bool lan_discovery_enabled)
+DHT *new_dht(const Logger *log, Mono_Time *mono_time, Networking_Core *net, bool hole_punching_enabled,
+             bool lan_discovery_enabled)
 {
     if (net == nullptr) {
         return nullptr;
@@ -2761,7 +2762,8 @@ void dht_save(const DHT *dht, uint8_t *data)
         }
     }
 
-    state_write_section_header(old_data, DHT_STATE_COOKIE_TYPE, pack_nodes(dht->log, data, sizeof(Node_format) * num, clients, num), DHT_STATE_TYPE_NODES);
+    state_write_section_header(old_data, DHT_STATE_COOKIE_TYPE, pack_nodes(dht->log, data, sizeof(Node_format) * num,
+                               clients, num), DHT_STATE_TYPE_NODES);
 
     free(clients);
 }

toxcore/DHT.h

@@ -22,6 +22,8 @@
 extern "C" {
 #endif
 
+/* Maximum size of a signature (may be smaller) */
+#define SIGNATURE_SIZE CRYPTO_SIGNATURE_SIZE
 /** Maximum number of clients stored per friend. */
 #define MAX_FRIEND_CLIENTS 8
 
@@ -64,6 +66,7 @@ extern "C" {
 #define CRYPTO_PACKET_DHTPK         156
 #define CRYPTO_PACKET_NAT_PING      254 // NAT ping crypto packet ID.
 
+/* Max size of a packed node for IPV4 and IPV6 respectively */
 #define PACKED_NODE_SIZE_IP4 (1 + SIZE_IP4 + sizeof(uint16_t) + CRYPTO_PUBLIC_KEY_SIZE)
 #define PACKED_NODE_SIZE_IP6 (1 + SIZE_IP6 + sizeof(uint16_t) + CRYPTO_PUBLIC_KEY_SIZE)
 
@@ -467,7 +470,8 @@ int dht_load(DHT *dht, const uint8_t *data, uint32_t length);
 
 /** Initialize DHT. */
 non_null()
-DHT *new_dht(const Logger *log, Mono_Time *mono_time, Networking_Core *net, bool hole_punching_enabled, bool lan_discovery_enabled);
+DHT *new_dht(const Logger *log, Mono_Time *mono_time, Networking_Core *net, bool hole_punching_enabled,
+             bool lan_discovery_enabled);
 
 non_null()
 void kill_dht(DHT *dht);

toxcore/crypto_core.c

@@ -33,6 +33,12 @@
 #define crypto_box_MACBYTES (crypto_box_ZEROBYTES - crypto_box_BOXZEROBYTES)
 #endif
 
+#ifndef VANILLA_NACL
+// Need dht because of ENC_SECRET_KEY_SIZE and ENC_PUBLIC_KEY_SIZE
+#define ENC_PUBLIC_KEY_SIZE CRYPTO_PUBLIC_KEY_SIZE
+#define ENC_SECRET_KEY_SIZE CRYPTO_SECRET_KEY_SIZE
+#endif
+
 //!TOKSTYLE-
 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
 #include "../testing/fuzzing/fuzz_adapter.h"
@@ -58,6 +64,31 @@ static_assert(CRYPTO_SHA512_SIZE == crypto_hash_sha512_BYTES,
 static_assert(CRYPTO_PUBLIC_KEY_SIZE == 32,
               "CRYPTO_PUBLIC_KEY_SIZE is required to be 32 bytes for public_key_eq to work");
 
+#ifndef VANILLA_NACL
+static_assert(CRYPTO_SIGNATURE_SIZE == crypto_sign_BYTES,
+              "CRYPTO_SIGNATURE_SIZE should be equal to crypto_sign_BYTES");
+static_assert(CRYPTO_SIGN_PUBLIC_KEY_SIZE == crypto_sign_PUBLICKEYBYTES,
+              "CRYPTO_SIGN_PUBLIC_KEY_SIZE should be equal to crypto_sign_PUBLICKEYBYTES");
+static_assert(CRYPTO_SIGN_SECRET_KEY_SIZE == crypto_sign_SECRETKEYBYTES,
+              "CRYPTO_SIGN_SECRET_KEY_SIZE should be equal to crypto_sign_SECRETKEYBYTES");
+#endif /* VANILLA_NACL */
+
+#ifndef VANILLA_NACL
+bool create_extended_keypair(uint8_t *pk, uint8_t *sk)
+{
+    /* create signature key pair */
+    crypto_sign_keypair(pk + ENC_PUBLIC_KEY_SIZE, sk + ENC_SECRET_KEY_SIZE);
+
+    /* convert public signature key to public encryption key */
+    const int res1 = crypto_sign_ed25519_pk_to_curve25519(pk, pk + ENC_PUBLIC_KEY_SIZE);
+
+    /* convert secret signature key to secret encryption key */
+    const int res2 = crypto_sign_ed25519_sk_to_curve25519(sk, sk + ENC_SECRET_KEY_SIZE);
+
+    return res1 == 0 && res2 == 0;
+}
+#endif
+
 #if !defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
 static uint8_t *crypto_malloc(size_t bytes)
 {
@@ -177,6 +208,26 @@ uint32_t random_range_u32(uint32_t upper_bound)
 #endif  // VANILLA_NACL
 }
 
+bool crypto_signature_create(uint8_t *signature, const uint8_t *message, uint64_t message_length,
+                             const uint8_t *secret_key)
+{
+#ifdef VANILLA_NACL
+    return false;
+#else
+    return crypto_sign_detached(signature, nullptr, message, message_length, secret_key) == 0;
+#endif // VANILLA_NACL
+}
+
+bool crypto_signature_verify(const uint8_t *signature, const uint8_t *message, uint64_t message_length,
+                             const uint8_t *public_key)
+{
+#ifdef VANILLA_NACL
+    return false;
+#else
+    return crypto_sign_verify_detached(signature, message, message_length, public_key) == 0;
+#endif
+}
+
 bool public_key_valid(const uint8_t *public_key)
 {
     if (public_key[31] >= 128) { /* Last bit of key is always zero. */

toxcore/crypto_core.h

@@ -19,6 +19,21 @@
 extern "C" {
 #endif
 
+/**
+ * The number of bytes in a signature.
+ */
+#define CRYPTO_SIGNATURE_SIZE          64
+
+/**
+ * The number of bytes in a Tox public key used for signatures.
+ */
+#define CRYPTO_SIGN_PUBLIC_KEY_SIZE    32
+
+/**
+ * The number of bytes in a Tox secret key used for signatures.
+ */
+#define CRYPTO_SIGN_SECRET_KEY_SIZE    64
+
 /**
  * @brief The number of bytes in a Tox public key used for encryption.
  */
@@ -60,6 +75,41 @@ extern "C" {
  */
 #define CRYPTO_SHA512_SIZE             64
 
+/**
+ * @brief The number of bytes in an encryption public key used by DHT group chats.
+ */
+#define ENC_PUBLIC_KEY_SIZE            CRYPTO_PUBLIC_KEY_SIZE
+
+/**
+ * @brief The number of bytes in an encryption secret key used by DHT group chats.
+ */
+#define ENC_SECRET_KEY_SIZE            CRYPTO_SECRET_KEY_SIZE
+
+/**
+ * @brief The number of bytes in a signature public key.
+ */
+#define SIG_PUBLIC_KEY_SIZE            CRYPTO_SIGN_PUBLIC_KEY_SIZE
+
+/**
+ * @brief The number of bytes in a signature secret key.
+ */
+#define SIG_SECRET_KEY_SIZE            CRYPTO_SIGN_SECRET_KEY_SIZE
+
+/**
+ * @brief The number of bytes in a DHT group chat public key identifier.
+ */
+#define CHAT_ID_SIZE                   SIG_PUBLIC_KEY_SIZE
+
+/**
+ * @brief The number of bytes in an extended public key used by DHT group chats.
+ */
+#define EXT_PUBLIC_KEY_SIZE            (ENC_PUBLIC_KEY_SIZE + SIG_PUBLIC_KEY_SIZE)
+
+/**
+ * @brief The number of bytes in an extended secret key used by DHT group chats.
+ */
+#define EXT_SECRET_KEY_SIZE            (ENC_SECRET_KEY_SIZE + SIG_SECRET_KEY_SIZE)
+
 /**
  * @brief A `bzero`-like function which won't be optimised away by the compiler.
  *
@@ -129,6 +179,36 @@ uint64_t random_u64(void);
  */
 uint32_t random_range_u32(uint32_t upper_bound);
 
+/** @brief Cryptographically signs a message using the supplied secret key and puts the resulting signature
+ * in the supplied buffer.
+ *
+ * @param signature The buffer for the resulting signature, which must have room for at
+ *   least CRYPTO_SIGNATURE_SIZE bytes.
+ * @param message The message being signed.
+ * @param message_length The length in bytes of the message being signed.
+ * @param secret_key The secret key used to create the signature. The key should be
+ *   produced by either `create_extended_keypair` or the libsodium function `crypto_sign_keypair`.
+ *
+ * @retval true on success.
+ */
+non_null()
+bool crypto_signature_create(uint8_t *signature, const uint8_t *message, uint64_t message_length,
+                             const uint8_t *secret_key);
+
+/** @brief Verifies that the given signature was produced by a given message and public key.
+ *
+ * @param signature The signature we wish to verify.
+ * @param message The message we wish to verify.
+ * @param message_length The length of the message.
+ * @param public_key The public key counterpart of the secret key that was used to
+ *   create the signature.
+ *
+ * @retval true on success.
+ */
+non_null()
+bool crypto_signature_verify(const uint8_t *signature, const uint8_t *message, uint64_t message_length,
+                             const uint8_t *public_key);
+
 /**
  * @brief Fill the given nonce with random bytes.
  */
@@ -151,6 +231,17 @@ void random_bytes(uint8_t *bytes, size_t length);
 non_null()
 bool public_key_valid(const uint8_t *public_key);
 
+/** @brief Creates an extended keypair: curve25519 and ed25519 for encryption and signing
+ *   respectively. The Encryption keys are derived from the signature keys.
+ *
+ * @param pk The buffer where the public key will be stored. Must have room for EXT_PUBLIC_KEY_SIZE bytes.
+ * @param sk The buffer where the secret key will be stored. Must have room for EXT_SECRET_KEY_SIZE bytes.
+ *
+ * @retval true on success.
+ */
+non_null()
+bool create_extended_keypair(uint8_t *pk, uint8_t *sk);
+
 /**
  * @brief Generate a new random keypair.
  *