Friends implementation

daemon/BUILD

@@ -47,6 +47,7 @@ rust_static_library(
     compile_data = [":migrations"],
     deps = [
         ":db_bridge",
+        "@crate_index//:anyhow",
         "@crate_index//:diesel",
         "@crate_index//:diesel_migrations",
         "@crate_index//:libsqlite3-sys",

daemon/README.md

@@ -6,7 +6,7 @@ Set up VSCode rust-analyzer (very recommended!):
 bazelisk run @rules_rust//tools/rust_analyzer:gen_rust_project
 ```
 
-# Database changes
+## Database changes
 
 We want to create a migration!
 
@@ -25,3 +25,11 @@ and
 ```
 ./diesel-cli.sh migration redo
 ```
+
+## Debugging
+
+For debugging the Rust code, run
+
+```
+bazelisk test //... --test_env=RUST_BACKTRACE=1
+```

daemon/crypto/constants.hpp

@@ -8,33 +8,34 @@
 #include "sodium.h"
 
 // MAC bytes
-constexpr size_t CRYPTO_ABYTES = crypto_aead_xchacha20poly1305_ietf_ABYTES;
+constexpr int CRYPTO_ABYTES = crypto_aead_xchacha20poly1305_ietf_ABYTES;
 // nonce bytes
-constexpr size_t CRYPTO_NPUBBYTES =
-    crypto_aead_xchacha20poly1305_ietf_NPUBBYTES;
+constexpr int CRYPTO_NPUBBYTES = crypto_aead_xchacha20poly1305_ietf_NPUBBYTES;
 // the maximum size of a message such that it can be sent in a single message
 // if the message is this size or shorter, it is guaranteed to be sent in a
 // single round. 1+5 is for the uint32 ID, 1+MESSAGE_SIZE is for the header of
 // the string, and 1 + 5 is for num_chunks and 1 + 5 is for
 // chunks_start_sequence_number element. -1 at the end is for the padding which
 // reserves one byte.
-constexpr size_t GUARANTEED_SINGLE_MESSAGE_SIZE =
+constexpr int GUARANTEED_SINGLE_MESSAGE_SIZE =
     MESSAGE_SIZE - (1 + 5) -
     (1 +
      CEIL_DIV((sizeof MESSAGE_SIZE) * 8 - std::countl_zero(MESSAGE_SIZE), 8)) -
     (1 + 5) - (1 + 5) - CRYPTO_ABYTES - 1 - CRYPTO_NPUBBYTES;
 
 // we support up to 4 billion messages! that's a lot.
 // (we use unsigned integers)
-constexpr size_t ACKING_BYTES = 4;
+constexpr int ACKING_BYTES = 4;
 // the encryption takes a nonce + a mac
-constexpr size_t ENCRYPTED_ACKING_BYTES =
+constexpr int ENCRYPTED_ACKING_BYTES =
     ACKING_BYTES + CRYPTO_ABYTES + CRYPTO_NPUBBYTES;
 // the maximum number of friends!
-constexpr size_t MAX_FRIENDS = MESSAGE_SIZE / ENCRYPTED_ACKING_BYTES;
+constexpr int MAX_FRIENDS = MESSAGE_SIZE / ENCRYPTED_ACKING_BYTES;
 
-constexpr size_t MAX_ASYNC_FRIEND_REQUESTS = 500;
-constexpr size_t ASYNC_FRIEND_REQUEST_BATCH_SIZE = 1000;
+constexpr int MAX_ASYNC_FRIEND_REQUESTS = 500;
+constexpr int ASYNC_FRIEND_REQUEST_BATCH_SIZE = 1000;
+// TODO: figure out a reasonable limit here...
+constexpr int INVITATION_MESSAGE_MAX_PLAINTEXT_SIZE = 500;
 
 // NOTE: whenever these default values are changed, please make a database
 // migration in the shape of UPDATE config SET value = 'new_value' WHERE value =

daemon/crypto/crypto.cc

@@ -546,6 +546,9 @@ auto decrypt_async_friend_request_public_key_only(
   // TODO: insert additional checks here
   // read the allocation
   // create the friend
+  // TODO: specifically, we need to verify that the public_id in the body
+  // corresponds to the public_id that the message was authenticated with
+  // otherwise, someone might impersonate the real receiver
   return std::make_pair(split_plaintext[0], split_plaintext[1]);
 }
 }  // namespace crypto