Read more about k-anonymity [here](https://en.wikipedia.org/wiki/K-anonymity). We implement this feature in the monero daemon for transactions
by providing a "Txid Template", which is simply a txid with all but `num_matching_bits` bits zeroed out, and the number `num_matching_bits`. We add an operation to `BlockchainLMDB` called
`get_txids_loose` which takes a txid template and returns all txids in the database (chain and mempool) that satisfy that template. Thus, a client can
ask about a specific transaction from a daemon without revealing the exact transaction they are inquiring about. The client can control the statistical
chance that other TXIDs (besides the one in question) match the txid template sent to the daemon up to a power of 2. For example, if a client sets their `num_matching_bits`
to 5, then statistically any txid has a 1/(2^5) chance to match. With `num_matching_bits`=10, there is a 1/(2^10) chance, so on and so forth.
Co-authored-by: ACK-J <60232273+ACK-J@users.noreply.github.com>
All the files in src/platform are currently unused and unnecessary. See below:
* `mingw/alloca.h`: unused throughout project
* `msc/sys/param.h`:
1. In `fix_darwin.patch`, `sys/param.h` is well-defined to be used only in OpenBSD environment
2. `int-util.h` already handles when `sys/param.h` is not present and injects its own values
3. `db_drivers/liblmdb/mdb.c` is a similar situation: already explicity handles different platforms
4. `src/crypto/chacha.h` uses `int-util.h` for endianness context
* `msc/alloca.h`: unused
* `msc/inline_c.h`: not needed. the `inline` keyword is supported for C99 I believe, and certainly for C11, C14+
* `msc/stdbool.h`: `stdbool.h` is standard since C99, and MSVC has supported it for a long time (~10 years)
eeda4a8 wallet2: do not lose exception in current thread on refresh (Crypto City
f868768 wallet2: fix missing exceptions from failing wallet refresh (Crypto City)
- Detach & re-process txs >= lowest scan height
- ensures that if a user calls scan_tx(tx1) after scanning tx2,
the wallet correctly processes tx1 and tx2
- if a user provides a tx with a height higher than the wallet's
last scanned height, the wallet will scan starting from that tx's
height
- scan_tx requires trusted daemon iff need to re-process existing
txs: in addition to querying a daemon for txids, if a user
provides a txid of a tx with height *lower* than any *already*
scanned txs in the wallet, then the wallet will also query the
daemon for all the *higher* txs as well. This is likely
unexpected behavior to a caller, and so to protect a caller from
revealing txid's to an untrusted daemon in an unexpected way,
require the daemon be trusted.
