Daemons intended for public use can be set up to require payment
in the form of hashes in exchange for RPC service. This enables
public daemons to receive payment for their work over a large
number of calls. This system behaves similarly to a pool, so
payment takes the form of valid blocks every so often, yielding
a large one off payment, rather than constant micropayments.
This system can also be used by third parties as a "paywall"
layer, where users of a service can pay for use by mining Monero
to the service provider's address. An example of this for web
site access is Primo, a Monero mining based website "paywall":
https://github.com/selene-kovri/primo
This has some advantages:
- incentive to run a node providing RPC services, thereby promoting the availability of third party nodes for those who can't run their own
- incentive to run your own node instead of using a third party's, thereby promoting decentralization
- decentralized: payment is done between a client and server, with no third party needed
- private: since the system is "pay as you go", you don't need to identify yourself to claim a long lived balance
- no payment occurs on the blockchain, so there is no extra transactional load
- one may mine with a beefy server, and use those credits from a phone, by reusing the client ID (at the cost of some privacy)
- no barrier to entry: anyone may run a RPC node, and your expected revenue depends on how much work you do
- Sybil resistant: if you run 1000 idle RPC nodes, you don't magically get more revenue
- no large credit balance maintained on servers, so they have no incentive to exit scam
- you can use any/many node(s), since there's little cost in switching servers
- market based prices: competition between servers to lower costs
- incentive for a distributed third party node system: if some public nodes are overused/slow, traffic can move to others
- increases network security
- helps counteract mining pools' share of the network hash rate
- zero incentive for a payer to "double spend" since a reorg does not give any money back to the miner
And some disadvantages:
- low power clients will have difficulty mining (but one can optionally mine in advance and/or with a faster machine)
- payment is "random", so a server might go a long time without a block before getting one
- a public node's overall expected payment may be small
Public nodes are expected to compete to find a suitable level for
cost of service.
The daemon can be set up this way to require payment for RPC services:
monerod --rpc-payment-address 4xxxxxx \
--rpc-payment-credits 250 --rpc-payment-difficulty 1000
These values are an example only.
The --rpc-payment-difficulty switch selects how hard each "share" should
be, similar to a mining pool. The higher the difficulty, the fewer
shares a client will find.
The --rpc-payment-credits switch selects how many credits are awarded
for each share a client finds.
Considering both options, clients will be awarded credits/difficulty
credits for every hash they calculate. For example, in the command line
above, 0.25 credits per hash. A client mining at 100 H/s will therefore
get an average of 25 credits per second.
For reference, in the current implementation, a credit is enough to
sync 20 blocks, so a 100 H/s client that's just starting to use Monero
and uses this daemon will be able to sync 500 blocks per second.
The wallet can be set to automatically mine if connected to a daemon
which requires payment for RPC usage. It will try to keep a balance
of 50000 credits, stopping mining when it's at this level, and starting
again as credits are spent. With the example above, a new client will
mine this much credits in about half an hour, and this target is enough
to sync 500000 blocks (currently about a third of the monero blockchain).
There are three new settings in the wallet:
- credits-target: this is the amount of credits a wallet will try to
reach before stopping mining. The default of 0 means 50000 credits.
- auto-mine-for-rpc-payment-threshold: this controls the minimum
credit rate which the wallet considers worth mining for. If the
daemon credits less than this ratio, the wallet will consider mining
to be not worth it. In the example above, the rate is 0.25
- persistent-rpc-client-id: if set, this allows the wallet to reuse
a client id across runs. This means a public node can tell a wallet
that's connecting is the same as one that connected previously, but
allows a wallet to keep their credit balance from one run to the
other. Since the wallet only mines to keep a small credit balance,
this is not normally worth doing. However, someone may want to mine
on a fast server, and use that credit balance on a low power device
such as a phone. If left unset, a new client ID is generated at
each wallet start, for privacy reasons.
To mine and use a credit balance on two different devices, you can
use the --rpc-client-secret-key switch. A wallet's client secret key
can be found using the new rpc_payments command in the wallet.
Note: anyone knowing your RPC client secret key is able to use your
credit balance.
The wallet has a few new commands too:
- start_mining_for_rpc: start mining to acquire more credits,
regardless of the auto mining settings
- stop_mining_for_rpc: stop mining to acquire more credits
- rpc_payments: display information about current credits with
the currently selected daemon
The node has an extra command:
- rpc_payments: display information about clients and their
balances
The node will forget about any balance for clients which have
been inactive for 6 months. Balances carry over on node restart.
If the peer (whether pruned or not itself) supports sending pruned blocks
to syncing nodes, the pruned version will be sent along with the hash
of the pruned data and the block weight. The original tx hashes can be
reconstructed from the pruned txes and theur prunable data hash. Those
hashes and the block weights are hashes and checked against the set of
precompiled hashes, ensuring the data we received is the original data.
It is currently not possible to use this system when not using the set
of precompiled hashes, since block weights can not otherwise be checked
for validity.
This is off by default for now, and is enabled by --sync-pruned-blocks
2cd4fd8 Changed the use of boost:value_initialized for C++ list initializer (JesusRami)
4ad191f Removed unused boost/value_init header (whyamiroot)
928f4be Make null hash constants constexpr (whyamiroot)
One considers the blockchain, while the other considers the
blockchain and some recent actions, such as a recently created
transaction which spend some outputs, but isn't yet mined.
Typically, the "balance" command wants the latter, to reflect
the recent action, but things like proving ownership wants
the former.
This fixes a crash in get_reserve_proof, where a preliminary
check and the main code used two concepts of "balance".
bdfc63a Add ref-counted buffer byte_slice. Currently used for sending TCP data. (vtnerd)
3b24b1d Added support for 'noise' over I1P/Tor to mask Tx transmission. (vtnerd)
914b106 wallet_rpc_server: use original addresses in destinations in get_transfers (moneromooo-monero)
da694d4 functional_tests: add tests for pending/out transfer addresses (moneromooo-monero)
c8709fe wallet: do not print log settings when unset (moneromooo-monero)
7b18e83 unit_tests: check return values on test data parsing (moneromooo-monero)
eeca5ca epee: support unicode in parsed strings (moneromooo-monero)
3e11bb5 functional_tests: test creating wallets with local language names (moneromooo-monero)
According to [1], std::random_shuffle is deprecated in C++14 and removed
in C++17. Since std::shuffle is available since C++11 as a replacement
and monero already requires C++11, this is a good replacement.
A cryptographically secure random number generator is used in all cases
to prevent people from perhaps copying an insecure std::shuffle call
over to a place where a secure one would be warranted. A form of
defense-in-depth.
[1]: https://en.cppreference.com/w/cpp/algorithm/random_shuffle
When the wallet auto refreshes after mining the last two blocks
but before popping them, it will then try to use outputs which
are not unlocked yet. This is really a wallet problem, which
will be fixed later.
aba2b2e7 functional_tests: reset blockchain on test start (moneromooo-monero)
375fde94 hardfork: fix off by one updating fork index after popping (moneromooo-monero)
e9fac29a unit_tests/long_term_block_weight: some tweaks that seem to make more sense (stoffu)
467f4c7e tests/block_weight: use integer division when computing median (stoffu)
815d08dc tests/block_weight: remove unused MULTIPLIER_SMALL (stoffu)
661f1fb8 blockchain: remove unused calc of short_term_constraint (stoffu)
The db txn in add_block ending caused the entire overarching
batch txn to stop.
Also add a new guard class so a db txn can be stopped in the
face of exceptions.
Also use a read only db txn in init when the db itself is
read only, and do not save the max tx size in that case.
0eee6cd7 block_weight: catch exceptions in main for clean exit on error (moneromooo-monero)
4b3bb829 epee: init a new ssl related variable in ctor (moneromooo-monero)
ae6885f6 blockchain: incremental long term block weight cache (moneromooo-monero)
9b687c78 blockchain: simple cache for the long term block weights (moneromooo-monero)
It allows one to connect to a running daemon or wallet, and use
its RPC API from python.
Usage: python -i console.py <port>
It will detect whether it's talking to a daemon or wallet and
initialize itself accordingly.
- tests fixes for HF10, builder change, rct_config; fix_chain
- get_tx_key test
- proper testing after live refresh added
- live refresh synthetic test
- log available funds for easier test construction
- wallet::API tests with mocked daemon
RPC connections now have optional tranparent SSL.
An optional private key and certificate file can be passed,
using the --{rpc,daemon}-ssl-private-key and
--{rpc,daemon}-ssl-certificate options. Those have as
argument a path to a PEM format private private key and
certificate, respectively.
If not given, a temporary self signed certificate will be used.
SSL can be enabled or disabled using --{rpc}-ssl, which
accepts autodetect (default), disabled or enabled.
Access can be restricted to particular certificates using the
--rpc-ssl-allowed-certificates, which takes a list of
paths to PEM encoded certificates. This can allow a wallet to
connect to only the daemon they think they're connected to,
by forcing SSL and listing the paths to the known good
certificates.
To generate long term certificates:
openssl genrsa -out /tmp/KEY 4096
openssl req -new -key /tmp/KEY -out /tmp/REQ
openssl x509 -req -days 999999 -sha256 -in /tmp/REQ -signkey /tmp/KEY -out /tmp/CERT
/tmp/KEY is the private key, and /tmp/CERT is the certificate,
both in PEM format. /tmp/REQ can be removed. Adjust the last
command to set expiration date, etc, as needed. It doesn't
make a whole lot of sense for monero anyway, since most servers
will run with one time temporary self signed certificates anyway.
SSL support is transparent, so all communication is done on the
existing ports, with SSL autodetection. This means you can start
using an SSL daemon now, but you should not enforce SSL yet or
nothing will talk to you.
This curbs runaway growth while still allowing substantial
spikes in block weight
Original specification from ArticMine:
here is the scaling proposal
Define: LongTermBlockWeight
Before fork:
LongTermBlockWeight = BlockWeight
At or after fork:
LongTermBlockWeight = min(BlockWeight, 1.4*LongTermEffectiveMedianBlockWeight)
Note: To avoid possible consensus issues over rounding the LongTermBlockWeight for a given block should be calculated to the nearest byte, and stored as a integer in the block itself. The stored LongTermBlockWeight is then used for future calculations of the LongTermEffectiveMedianBlockWeight and not recalculated each time.
Define: LongTermEffectiveMedianBlockWeight
LongTermEffectiveMedianBlockWeight = max(300000, MedianOverPrevious100000Blocks(LongTermBlockWeight))
Change Definition of EffectiveMedianBlockWeight
From (current definition)
EffectiveMedianBlockWeight = max(300000, MedianOverPrevious100Blocks(BlockWeight))
To (proposed definition)
EffectiveMedianBlockWeight = min(max(300000, MedianOverPrevious100Blocks(BlockWeight)), 50*LongTermEffectiveMedianBlockWeight)
Notes:
1) There are no other changes to the existing penalty formula, median calculation, fees etc.
2) There is the requirement to store the LongTermBlockWeight of a block unencrypted in the block itself. This is to avoid possible consensus issues over rounding and also to prevent the calculations from becoming unwieldy as we move away from the fork.
3) When the EffectiveMedianBlockWeight cap is reached it is still possible to mine blocks up to 2x the EffectiveMedianBlockWeight by paying the corresponding penalty.
Note: the long term block weight is stored in the database, but not in the actual block itself,
since it requires recalculating anyway for verification.
- Support for ".onion" in --add-exclusive-node and --add-peer
- Add --anonymizing-proxy for outbound Tor connections
- Add --anonymous-inbounds for inbound Tor connections
- Support for sharing ".onion" addresses over Tor connections
- Support for broadcasting transactions received over RPC exclusively
over Tor (else broadcast over public IP when Tor not enabled).
b6534c40 ringct: remove unused senderPk from ecdhTuple (moneromooo-monero)
7d375981 ringct: the commitment mask is now deterministic (moneromooo-monero)
99d946e6 ringct: encode 8 byte amount, saving 24 bytes per output (moneromooo-monero)
cdc3ccec ringct: save 3 bytes on bulletproof size (moneromooo-monero)
f931e16c add a bulletproof version, new bulletproof type, and rct config (moneromooo-monero)
The blockchain prunes seven eighths of prunable tx data.
This saves about two thirds of the blockchain size, while
keeping the node useful as a sync source for an eighth
of the blockchain.
No other data is currently pruned.
There are three ways to prune a blockchain:
- run monerod with --prune-blockchain
- run "prune_blockchain" in the monerod console
- run the monero-blockchain-prune utility
The first two will prune in place. Due to how LMDB works, this
will not reduce the blockchain size on disk. Instead, it will
mark parts of the file as free, so that future data will use
that free space, causing the file to not grow until free space
grows scarce.
The third way will create a second database, a pruned copy of
the original one. Since this is a new file, this one will be
smaller than the original one.
Once the database is pruned, it will stay pruned as it syncs.
That is, there is no need to use --prune-blockchain again, etc.
464097e5 blockchain_ancestry: allow getting ancestry of a single output (moneromooo-monero)
a6216d1a blockchain_db: allow getting output keys without commitment (moneromooo-monero)
Number matching semantics are slightly changed: since this is used
as a filter to check whether a number is signed and/or floating
point, we can speed this up further. strto* functions are called
afterwards and will error out where necessary. We now also accept
numbers like .4 which were not accepted before.
The strto* calls on a boost::string_ref will not access unallocated
memory since the parsers always stop at the first bad character,
and the original string is zero terminated.
in arbitrary time measurement units for some arbitrary test case:
match_number2: 235 -> 70
match_word2: 330 -> 108
get_output_key method is commonly used when working with txs and their key images. Because the method is not const, passing blockchain object though const& or pointers to const is not possible in this context. This is especially problematic in external projects (e.g., projects in moneroexamples) that use monero C++ api to operate on the blockchain and txs.
Thus, having get_output_key method will simplify moving blockchain object around through const references and pointers to const objects.
a48f2dab blockchain_prune_known_spent_data: blackball file is now optional (moneromooo-monero)
17b45725 Outputs where all amounts are known spent can now be pruned (moneromooo-monero)
aee7a4e3 wallet_rpc_server: do not use RPC data if the call failed (moneromooo-monero)
1a0733e5 windows_service: fix memory leak (moneromooo-monero)
0dac3c64 unit_tests: do not rethrow a copy of an exception (moneromooo-monero)
5d9915ab cryptonote: fix get_unit for non default settings (moneromooo-monero)
d4f50cb1 remove some unused code (moneromooo-monero)
61163971 a few minor (but easy) performance tweaks (moneromooo-monero)
30023074 tests: slow_memmem now returns size_t (moneromooo-monero)
b36353e2 unit_tests: add some hex parsing test for non hex input (xiphon)
6671110c unit_tests: add a test for parse_hexstr_to_binbuff (moneromooo-monero)
f6187cd8 epee: speed up parse_hexstr_to_binbuff a little (Howard Chu)
Only for pre rct for obvious reasons.
Note: DO NOT use a known spent list which includes outputs
which are not known spent. If the list includes any output
that's just strongly thought to be spent, but not provably
so, you risk finding yourself unable to sync past the point
where that output is spent.
I estimate only 200 MB saved on current mainnet though,
unless the new blackballing rule unearths a good amount of
large-amount-set extra spent outs.
5808530f blockchain: remove unused output_scan_worker parameter (moneromooo-monero)
1426209a blockchain: don't run threads if we have just one function to run (moneromooo-monero)
6f7a5fd4 db_lmdb: slight speedup getting array data from the blockchain (moneromooo-monero)
99fbe100 db_lmdb: save some string copies for readonly db keys/values (moneromooo-monero)
bf31447e tx_pool: speed up take_tx for transactions from blocks (moneromooo-monero)
4f005a77 tx_pool: remove unnecessary get_transaction_hash (moneromooo-monero)
593ef598 perf_timer: call reserve on new timer array (moneromooo-monero)
6ecc99ad core: avoid unnecessary tx/blob conversions (moneromooo-monero)
00cc1a16 unit_tests: notify test special case for the usual weirdo (moneromooo-monero)
To help protect one's privacy from traffic volume analysis
for people using Tor or I2P. This will really fly once we
relay txes on a timer rather than on demand, though.
Off by default for now since it's wasteful and doesn't bring
anything until I2P's in.
74fb3d88 multiexp: some minor speedups (moneromooo-monero)
a6d2e246 bulletproofs: only enable profiling on request (moneromooo-monero)
a110e6aa multiexp: tune which variants to use for which number of points (moneromooo-monero)
8b476722 bulletproofs: speedup prover (moneromooo-monero)
6f9ae5b6 multiexp: handle pippenger multiexps with part precalc (moneromooo-monero)
10e5a927 bulletproofs: maintain -z4, -z5, and -y0 to avoid subtractions (moneromooo-monero)
8629a42c bulletproofs: rework flow to use sarang's fast batch inversion code (moneromooo-monero)
fc9f7d9c bulletproofs: merge multiexps as per sarang's new python code (moneromooo-monero)
4061960a multiexp: pack the digits table when STRAUS_C is 4 (moneromooo-monero)
bf8e4b98 bulletproofs: some more minor speedup (moneromooo-monero)
c415df97 performance_tests: sc_check and ge_dsm_precomp (moneromooo-monero)
a281b950 bulletproofs: remove single value prover (moneromooo-monero)
484155d0 bulletproofs: some more speedup (moneromooo-monero)
a621d6c8 bulletproofs: random minor speedups (moneromooo-monero)
a49a1761 bulletproofs: shave off a lot of scalar muls from the g/h construction (moneromooo-monero)
4564a5d1 bulletproofs: speedup PROVE (moneromooo-monero)
00901e9c epee: initialize a few data members where it seems to be appropriate (moneromooo-monero)
144a6c32 abstract_tcp_server2: move m_period to subclass (moneromooo-monero)
758d7684 connection_basic: remove unused floating time start time (moneromooo-monero)
e5108a29 Catch more exceptions in dtors (moneromooo-monero)
9acf42d3 Multisig M/N functionality core tests added (naughtyfox)
9f3963e8 Arbitrary M/N multisig schemes: * support in wallet2 * support in monero-wallet-cli * support in monero-wallet-rpc * support in wallet api * support in monero-gen-trusted-multisig * unit tests for multisig wallets creation (naughtyfox)
This removes some small amount of fingerprinting entropy.
There is no consensus rule to require this since this field
is technically free form, and a transaction is free to have
custom data in it.
* support in wallet2
* support in monero-wallet-cli
* support in monero-wallet-rpc
* support in wallet api
* support in monero-gen-trusted-multisig
* unit tests for multisig wallets creation
bcf3f6af fuzz_tests: catch unhandled exceptions (moneromooo-monero)
3ebd05d4 miner: restore stream flags after changing them (moneromooo-monero)
a093092e levin_protocol_handler_async: do not propagate exception through dtor (moneromooo-monero)
1eebb82b net_helper: do not propagate exceptions through dtor (moneromooo-monero)
fb6a3630 miner: do not propagate exceptions through dtor (moneromooo-monero)
2e2139ff epee: do not propagate exception through dtor (moneromooo-monero)
0749a8bd db_lmdb: do not propagate exceptions in dtor (moneromooo-monero)
1b0afeeb wallet_rpc_server: exit cleanly on unhandled exceptions (moneromooo-monero)
418a9936 unit_tests: catch unhandled exceptions (moneromooo-monero)
ea7f9543 threadpool: do not propagate exceptions through the dtor (moneromooo-monero)
6e855422 gen_multisig: nice exit on unhandled exception (moneromooo-monero)
53df2deb db_lmdb: catch error in mdb_stat calls during migration (moneromooo-monero)
e67016dd blockchain_blackball: catch failure to commit db transaction (moneromooo-monero)
661439f4 mlog: don't remove old logs if we failed to rename the current file (moneromooo-monero)
5fdcda50 easylogging++: test for NULL before dereference (moneromooo-monero)
7ece1550 performance_test: fix bad last argument calling add_arg (moneromooo-monero)
a085da32 unit_tests: add check for page size > 0 before dividing (moneromooo-monero)
d8b1ec8b unit_tests: use std::shared_ptr to shut coverity up about leaks (moneromooo-monero)
02563bf4 simplewallet: top level exception catcher to print nicer messages (moneromooo-monero)
c57a65b2 blockchain_blackball: fix shift range for 32 bit archs (moneromooo-monero)
26a42fe5 Added features to epee::span<T> : - Support for classes - Added `remove_prefix` function - Added `to_mut_span` and `as_mut_byte_span` (Lee Clagett)
56b50faa wallet: use wipeable_string in more places where a secret is used (moneromooo-monero)
07ec748c wipeable_string: add hex_to_pod function (moneromooo-monero)
a54dbaee blockchain_blackball: add --force-chain-reaction-pass flag (moneromooo-monero)
44439c32 record blackballs as amount/offset, and add export ability (moneromooo-monero)
4bce935b blockchain_blackball: more optimizations (moneromooo-monero)
b66ba783 blockchain_blackball: do not process duplicate blockchains parts (moneromooo-monero)
639a3c01 blockchain_blackball: make it clear secondary passes are not incremental (moneromooo-monero)
eb8a51be blockchain_blackball: detect spent outputs by partial ring reuse (moneromooo-monero)
d6d276c6 blockchain_blackball: fix chain reaction phase in incremental mode (moneromooo-monero)
2b2a681b blockchain_blackball: avoid false positives for different amounts (moneromooo-monero)
80e4fef3 blockchain_blackball: set transaction looping txn to read only (moneromooo-monero)
4801d6b5 blockchain_blackball: add stats (moneromooo-monero)
846190fd blockchain_blackball: support pre-v2 databases (moneromooo-monero)
daa6cc7d blockchain_blackball: use LMDB for the cache (moneromooo-monero)
50cb370d ringdb: allow blackballing many outputs at once (moneromooo-monero)
9137ad2c blockchain: add a testnet v9 a day after v8 (moneromooo-monero)
ac4f71c2 wallet2: bump testnet rollback to account for coming reorg (moneromooo-monero)
8f418a6d bulletproofs: #include <openssl/bn.h> (moneromooo-monero)
2bf63650 bulletproofs: speed up the latest changes a bit (moneromooo-monero)
044dff5a bulletproofs: scale points by 8 to ensure subgroup validity (moneromooo-monero)
c83012c4 bulletproofs: match aggregated verification to sarang's latest prototype (moneromooo-monero)
ce0c7432 performance_tests: add padded bulletproof construction (moneromooo-monero)
1224e53b core_tests: add a test for 4-aggregated BP verification (moneromooo-monero)
0e6ed559 fuzz_tests: add a bulletproof fuzz test (moneromooo-monero)
463434d1 more comprehensive test for ge_p3 comparison to identity/point at infinity (moneromooo-monero)
d0a0565f unit_tests: add a few more multiexp unit tests (moneromooo-monero)
6526d87f core_tests: add a test for a tx with empty bulletproof (moneromooo-monero)
a129bbd9 multiexp: fix maxscalar off by one (moneromooo-monero)
7ed496cc ringct: error out when hashToPoint* returns the point at infinity (moneromooo-monero)
d1591853 cryptonote_basic: check output type before using it (moneromooo-monero)
61632dc1 ringct: prevent a potential very large allocation (moneromooo-monero)
a4317e61 crypto: some paranoid checks in generate_signature/check_signature (moneromooo-monero)
7434df1c crypto: never return zero in random32_unbiased (moneromooo-monero)
0825e974 multiexp: fix wrong Bos-Coster result for 1 non trivial input (moneromooo-monero)
a1359ad4 Check inputs to addKeys are in range (moneromooo-monero)
fe0fa3b9 bulletproofs: reject x, y, z, or w[i] being zero (moneromooo-monero)
5ffb2ff9 v8: per byte fee, pad bulletproofs, fixed 11 ring size (moneromooo-monero)
869b3bf8 bulletproofs: a few fixes from the Kudelski review (moneromooo-monero)
c4291762 bulletproofs: reject points not in the main subgroup (moneromooo-monero)
15697177 bulletproofs: speed up a few multiplies using existing Hi cache (moneromooo-monero)
0b05a0fa Add Pippenger cache and limit Straus cache size (moneromooo-monero)
51eb3bdc add pippenger unit tests (moneromooo-monero)
b17b8db3 performance_tests: add stats and loop count multiplier options (moneromooo-monero)
7314d919 perf_timer: split timer class into a base one and a logging one (moneromooo-monero)
d126a02b performance_tests: add aggregated bulletproof tx verification (moneromooo-monero)
263431c4 Pippenger multiexp (moneromooo-monero)
1ed0ed4d multiexp: cut down on memory allocations (moneromooo-monero)
1b867e7f precalc the ge_p3 representation of H (moneromooo-monero)
ef56529f performance_tests: document the tested bulletproof layouts (moneromooo-monero)
30111780 unit_tests: a couple more bulletproof unit tests for gamma (moneromooo-monero)
c444b1b2 require canonical multi output bulletproof layout (moneromooo-monero)
7e67c52f Add a define for the max number of bulletproof multi-outputs (moneromooo-monero)
2a8fcb42 Bulletproof aggregated verification and tests (moneromooo-monero)
126196b0 multiexp: some speedups (moneromooo-monero)
71d67bda aligned: aligned memory alloc/realloc/free (moneromooo-monero)
cb9ecab1 performance_tests: add signature generation/verification (moneromooo-monero)
bacf0a1e bulletproofs: add aggregated verification (moneromooo-monero)
e895c3de make straus cached mode thread safe, and add tests for it (moneromooo-monero)
7f48bf05 multiexp: bos coster now works for just one point (moneromooo-monero)
9ce9f8ca bulletproofs: add multi output bulletproofs to rct (moneromooo-monero)
f34e2e20 performance_tests: add tx checking tests with more than 2 outputs (moneromooo-monero)
0793184b performance_tests: add a --verbose flag, and default to terse (moneromooo-monero)
939bc223 add Straus multiexp (moneromooo-monero)
9ff6e6a0 ringct: add bos coster multiexp (moneromooo-monero)
e9164bb3 bulletproofs: misc optimizations (moneromooo-monero)
112f32f0 performance_tests: add crypto ops (moneromooo-monero)
f5d7b993 performance_tests: add bulletproofs (moneromooo-monero)
8f4ce989 performance_tests: add RingCT MLSAG gen/ver tests (moneromooo-monero)
1aa10c43 performance_tests: add (Borromean) range proofs (moneromooo-monero)
aacfd6e3 bulletproofs: multi-output bulletproofs (moneromooo-monero)
cb1cc757 performance_tests: don't override log level to 0 (moneromooo-monero)
- fix integer overflow in n_bulletproof_amounts
- check input scalars are in range
- remove use of environment variable to tweak straus performance
- do not use implementation defined signed shift for signum
Contains two modifications to improve ASIC resistance: shuffle and integer math.
Shuffle makes use of the whole 64-byte cache line instead of 16 bytes only, making Cryptonight 4 times more demanding for memory bandwidth.
Integer math adds 64:32 bit integer division followed by 64 bit integer square root, adding large and unavoidable computational latency to the main loop.
More details and performance numbers: https://github.com/SChernykh/xmr-stak-cpu/blob/master/README.md
This class will allow mlocking small objects, of which there
may be several per page. It adds refcounting so pages are only
munlocked when the last object on that page munlocks.
The secret spend key is kept encrypted in memory, and
decrypted on the fly when needed.
Both spend and view secret keys are kept encrypted in a JSON
field in the keys file. This avoids leaving the keys in
memory due to being manipulated by the JSON I/O API.
63e342b crypto: move null_pkey/null_skey to the cpp file (moneromooo-monero)
0496c7c crypto: do not use boost::value_initialized to init null skey/pkey (moneromooo-monero)
Fixes failing test during Arch package build (due to attempt to write to
~/.bitmonero/...).
Prefix temp dir path with "monero-" because we are not putting it on the
system, so good to identify ourselves in case the dir gets left over due
to crash, etc.
149da42 db_lmdb: enable batch transactions by default (stoffu)
34cb6b4 add --regtest and --fixed-difficulty for regression testing (vicsn)
9e1403e update get_info RPC and bump RPC version (vicsn)
207b66e first new functional tests (vicsn)
This gets rid of the temporary precalc cache.
Also make the RPC able to send data back in binary or JSON,
since there can be a lot of data
This bumps the LMDB database format to v3, with migration.
on_generateblocks RPC call combines functionality from the on_getblocktemplate and on_submitblock RPC calls to allow rapid block creation. Difficulty is set permanently to 1 for regtest.
Makes use of FAKECHAIN network type, but takes hard fork heights from mainchain
Default reserve_size in generate_blocks RPC call is now 1. If it is 0, the following error occurs 'Failed to calculate offset for'.
Queries hard fork heights info of other network types
f8dd433 epee: fix detection of 172.16.0.0/172.31.255.255 local IP range (moneromooo-monero)
5db9e3c unit_tests: add tests for local IP range detection (moneromooo-monero)
db55263 threadpool: allow constructing an object, and misc tweaks (moneromooo-monero)
ce173cb core: remove threadpool dependency from header (moneromooo-monero)
3147468 unit_tests: add threadpool unit test (moneromooo-monero)
for privacy reasons, so an untrusted node can't easily track
wallets from IP address to IP address, etc. The granularity
is 1024 blocks, which is about a day and a half.
a connection's timeout is halved for every extra connection
from the same host.
Also keep track of when we don't need to use a connection
anymore, so we can close it and free the resource for another
connection.
Also use the longer timeout for non routable local addresses.
hash: add prehashed version cn_slow_hash_prehashed
slow-hash: let cn_slow_hash take 4th parameter for deciding prehashed or not
slow-hash: add support for prehashed version for the other 3 platforms
When #3303 was merged, a cyclic dependency chain was generated:
libdevice <- libcncrypto <- libringct <- libdevice
This was because libdevice needs access to a set of basic crypto operations
implemented in libringct such as scalarmultBase(), while libringct also needs
access to abstracted crypto operations implemented in libdevice such as
ecdhEncode(). To untangle this cyclic dependency chain, this patch splits libringct
into libringct_basic and libringct, where the basic crypto ops previously in
libringct are moved into libringct_basic. The cyclic dependency is now resolved
thanks to this separation:
libcncrypto <- libringct_basic <- libdevice <- libcryptonote_basic <- libringct
This eliminates the need for crypto_device.cpp and rctOps_device.cpp.
Also, many abstracted interfaces of hw::device such as encrypt_payment_id() and
get_subaddress_secret_key() were previously implemented in libcryptonote_basic
(cryptonote_format_utils.cpp) and were then called from hw::core::device_default,
which is odd because libdevice is supposed to be independent of libcryptonote_basic.
Therefore, those functions were moved to device_default.cpp.
0e7ad2e2 Wallet API: generalize 'bool testnet' to 'NetworkType nettype' (stoffu)
af773211 Stagenet (stoffu)
cc9a0bee command_line: allow args to depend on more than one args (stoffu)
55f8d917 command_line::get_arg: remove 'required' for dependent args as they're always optional (stoffu)
450306a0 command line: allow has_arg to handle arg_descriptor<bool,false,true> #3318 (stoffu)
9f9e095a Use `genesis_tx` parameter in `generate_genesis_block`. #3261 (Jean Pierre Dudey)
The basic approach it to delegate all sensitive data (master key, secret
ephemeral key, key derivation, ....) and related operations to the device.
As device has low memory, it does not keep itself the values
(except for view/spend keys) but once computed there are encrypted (with AES
are equivalent) and return back to monero-wallet-cli. When they need to be
manipulated by the device, they are decrypted on receive.
Moreover, using the client for storing the value in encrypted form limits
the modification in the client code. Those values are transfered from one
C-structure to another one as previously.
The code modification has been done with the wishes to be open to any
other hardware wallet. To achieve that a C++ class hw::Device has been
introduced. Two initial implementations are provided: the "default", which
remaps all calls to initial Monero code, and the "Ledger", which delegates
all calls to Ledger device.
e4646379 keccak: fix mdlen bounds sanity checking (moneromooo-monero)
2e3e90ac pass large parameters by const ref, not value (moneromooo-monero)
61defd89 blockchain: sanity check number of precomputed hash of hash blocks (moneromooo-monero)
9af6b2d1 ringct: fix infinite loop in unused h2b function (moneromooo-monero)
8cea8d0c simplewallet: double check a new multisig wallet is multisig (moneromooo-monero)
9b98a6ac threadpool: catch exceptions in dtor, to avoid terminate (moneromooo-monero)
24803ed9 blockchain_export: fix buffer overflow in exporter (moneromooo-monero)
f3f7da62 perf_timer: rewrite to make it clear there is no division by zero (moneromooo-monero)
c6ea3df0 performance_tests: remove add_arg call stray extra param (moneromooo-monero)
fa6b4566 fuzz_tests: fix an uninitialized var in setup (moneromooo-monero)
03887f11 keccak: fix sanity check bounds test (moneromooo-monero)
ad11db91 blockchain_db: initialize m_open in base class ctor (moneromooo-monero)
bece67f9 miner: restore std::cout precision after modification (moneromooo-monero)
1aabd14c db_lmdb: check hard fork info drop succeeded (moneromooo-monero)
6d8b29ef fix some link errors in debug mode for macos (stoffu)
fdd4c5e5 move memwipe to epee to avoid common<->crypto circular dependencies (moneromooo-monero)
40ab12a7 epee: remove dependency on common (moneromooo-monero)
bd5cce07 network_throttle: fix ineffective locking (moneromooo-monero)
e0a61299 network_throttle: remove unused xxx static member (moneromooo-monero)
24f584d9 cryptonote_core: remove unused functions with off by one bugs (moneromooo-monero)
b1634aa3 blockchain: don't leave dangling pointers in this (moneromooo-monero)
8e60b81c cryptonote_core: fix db leak on error (moneromooo-monero)
213e326c abstract_tcp_server2: log init_server errors as fatal (moneromooo-monero)
b51dc566 use const refs in for loops for non tiny types (moneromooo-monero)
f0568ca6 net_parse_helpers: fix regex error checking (moneromooo-monero)
b49ddc76 check accessing an element past the end of a container (moneromooo-monero)
2305bf26 check return value for generate_key_derivation and derive_public_key (moneromooo-monero)
a4240d9f catch const exceptions (moneromooo-monero)
45a1c4c0 add empty container sanity checks when using front() and back() (moneromooo-monero)
56fa6ce1 tests: fix a buffer overread in a unit test (moneromooo-monero)
b4524892 rpc: guard against json parsing a non object (moneromooo-monero)
c2ed8618 easylogging++: avoid buffer underflow (moneromooo-monero)
187a6ab2 epee: trap failure to parse URI from request (moneromooo-monero)
061789b5 checkpoints: trap failure to load JSON checkpoints (moneromooo-monero)
ba2fefb9 checkpoints: pass std::string by const ref, not const value (moneromooo-monero)
38c8f4e0 mlog: terminate a string at last char, just in case (moneromooo-monero)
d753d716 fix a few leaks by throwing objects, not newed pointers to objects (moneromooo-monero)
fe568db8 p2p: use size_t for arbitrary counters instead of uint8_t (moneromooo-monero)
46d6fa35 cryptonote_protocol: sanity check chain hashes from peer (moneromooo-monero)
25584f86 cryptonote_protocol: print peer versions when unexpected (moneromooo-monero)
490a5d41 rpc: do not try to use an invalid txid in relay_tx (moneromooo-monero)
Scheme by luigi1111:
Multisig for RingCT on Monero
2 of 2
User A (coordinator):
Spendkey b,B
Viewkey a,A (shared)
User B:
Spendkey c,C
Viewkey a,A (shared)
Public Address: C+B, A
Both have their own watch only wallet via C+B, a
A will coordinate spending process (though B could easily as well, coordinator is more needed for more participants)
A and B watch for incoming outputs
B creates "half" key images for discovered output D:
I2_D = (Hs(aR)+c) * Hp(D)
B also creates 1.5 random keypairs (one scalar and 2 pubkeys; one on base G and one on base Hp(D)) for each output, storing the scalar(k) (linked to D),
and sending the pubkeys with I2_D.
A also creates "half" key images:
I1_D = (Hs(aR)+b) * Hp(D)
Then I_D = I1_D + I2_D
Having I_D allows A to check spent status of course, but more importantly allows A to actually build a transaction prefix (and thus transaction).
A builds the transaction until most of the way through MLSAG_Gen, adding the 2 pubkeys (per input) provided with I2_D
to his own generated ones where they are needed (secret row L, R).
At this point, A has a mostly completed transaction (but with an invalid/incomplete signature). A sends over the tx and includes r,
which allows B (with the recipient's address) to verify the destination and amount (by reconstructing the stealth address and decoding ecdhInfo).
B then finishes the signature by computing ss[secret_index][0] = ss[secret_index][0] + k - cc[secret_index]*c (secret indices need to be passed as well).
B can then broadcast the tx, or send it back to A for broadcasting. Once B has completed the signing (and verified the tx to be valid), he can add the full I_D
to his cache, allowing him to verify spent status as well.
NOTE:
A and B *must* present key A and B to each other with a valid signature proving they know a and b respectively.
Otherwise, trickery like the following becomes possible:
A creates viewkey a,A, spendkey b,B, and sends a,A,B to B.
B creates a fake key C = zG - B. B sends C back to A.
The combined spendkey C+B then equals zG, allowing B to spend funds at any time!
The signature fixes this, because B does not know a c corresponding to C (and thus can't produce a signature).
2 of 3
User A (coordinator)
Shared viewkey a,A
"spendkey" j,J
User B
"spendkey" k,K
User C
"spendkey" m,M
A collects K and M from B and C
B collects J and M from A and C
C collects J and K from A and B
A computes N = nG, n = Hs(jK)
A computes O = oG, o = Hs(jM)
B anc C compute P = pG, p = Hs(kM) || Hs(mK)
B and C can also compute N and O respectively if they wish to be able to coordinate
Address: N+O+P, A
The rest follows as above. The coordinator possesses 2 of 3 needed keys; he can get the other
needed part of the signature/key images from either of the other two.
Alternatively, if secure communication exists between parties:
A gives j to B
B gives k to C
C gives m to A
Address: J+K+M, A
3 of 3
Identical to 2 of 2, except the coordinator must collect the key images from both of the others.
The transaction must also be passed an additional hop: A -> B -> C (or A -> C -> B), who can then broadcast it
or send it back to A.
N-1 of N
Generally the same as 2 of 3, except participants need to be arranged in a ring to pass their keys around
(using either the secure or insecure method).
For example (ignoring viewkey so letters line up):
[4 of 5]
User: spendkey
A: a
B: b
C: c
D: d
E: e
a -> B, b -> C, c -> D, d -> E, e -> A
Order of signing does not matter, it just must reach n-1 users. A "remaining keys" list must be passed around with
the transaction so the signers know if they should use 1 or both keys.
Collecting key image parts becomes a little messy, but basically every wallet sends over both of their parts with a tag for each.
Thia way the coordinating wallet can keep track of which images have been added and which wallet they come from. Reasoning:
1. The key images must be added only once (coordinator will get key images for key a from both A and B, he must add only one to get the proper key actual key image)
2. The coordinator must keep track of which helper pubkeys came from which wallet (discussed in 2 of 2 section). The coordinator
must choose only one set to use, then include his choice in the "remaining keys" list so the other wallets know which of their keys to use.
You can generalize it further to N-2 of N or even M of N, but I'm not sure there's legitimate demand to justify the complexity. It might
also be straightforward enough to support with minimal changes from N-1 format.
You basically just give each user additional keys for each additional "-1" you desire. N-2 would be 3 keys per user, N-3 4 keys, etc.
The process is somewhat cumbersome:
To create a N/N multisig wallet:
- each participant creates a normal wallet
- each participant runs "prepare_multisig", and sends the resulting string to every other participant
- each participant runs "make_multisig N A B C D...", with N being the threshold and A B C D... being the strings received from other participants (the threshold must currently equal N)
As txes are received, participants' wallets will need to synchronize so that those new outputs may be spent:
- each participant runs "export_multisig FILENAME", and sends the FILENAME file to every other participant
- each participant runs "import_multisig A B C D...", with A B C D... being the filenames received from other participants
Then, a transaction may be initiated:
- one of the participants runs "transfer ADDRESS AMOUNT"
- this partly signed transaction will be written to the "multisig_monero_tx" file
- the initiator sends this file to another participant
- that other participant runs "sign_multisig multisig_monero_tx"
- the resulting transaction is written to the "multisig_monero_tx" file again
- if the threshold was not reached, the file must be sent to another participant, until enough have signed
- the last participant to sign runs "submit_multisig multisig_monero_tx" to relay the transaction to the Monero network
43f5269f Wallets now do not depend on the daemon rpc lib (moneromooo-monero)
bb89ae8b move connection_basic and network_throttle from src/p2p to epee (moneromooo-monero)
4abf25f3 cryptonote_core does not depend on p2p anymore (moneromooo-monero)
Partially implements #74.
Securely erases keys from memory after they are no longer needed. Might have a
performance impact, which I haven't measured (perf measurements aren't
generally reliable on laptops).
Thanks to @stoffu for the suggestion to specialize the pod_to_hex/hex_to_pod
functions. Using overloads + SFINAE instead generalizes it so other types can
be marked as scrubbed without adding more boilerplate.
3dffe71b new wipeable_string class to replace std::string passphrases (moneromooo-monero)
7a2a5741 utils: initialize easylogging++ in on_startup (moneromooo-monero)
54950829 use memwipe in a few relevant places (moneromooo-monero)
000666ff add a memwipe function (moneromooo-monero)
0d9c0db9 Do not build against epee_readline if it was not built (Howard Chu)
178014c9 split off readline code into epee_readline (moneromooo-monero)
a9e14a19 link against readline only for monerod and wallet-wallet-{rpc,cli} (moneromooo-monero)
437421ce wallet: move some scoped_message_writer calls from the libs (moneromooo-monero)
e89994e9 wallet: rejig to avoid prompting in wallet2 (moneromooo-monero)
ec5135e5 move input_line from command_line to simplewallet (moneromooo-monero)
082db75f move cryptonote command line options to cryptonote_core (moneromooo-monero)
This patch allows to filter out sensitive information for queries that rely on the pool state, when running in restricted mode.
This filtering is only applied to data sent back to RPC queries. Results of inline commands typed locally in the daemon are not affected.
In practice, when running with `--restricted-rpc`:
* get_transaction_pool will list relayed transactions with the fields "last relayed time" and "received time" set to zero.
* get_transaction_pool will not list transaction that have do_not_relay set to true, and will not list key images that are used only for such transactions
* get_transaction_pool_hashes.bin will not list such transaction
* get_transaction_pool_stats will not count such transactions in any of the aggregated values that are computed
The implementation does not make filtering the default, so developers should be mindful of this if they add new RPC functionality.
Fixes#2590.
ff7745bb Edited test readme for accuracy and depth (Cole Lightfighter)
c300ae56 Added test documentation & Keccak unit test (Cole Lightfighter)
f6119a8e Added test documentation & Keccak unit test (Cole Lightfighter)
Tests for checking proper error throwing for out-of-bounds subaddress
indexes, and proper addition of subaddresses.
Signed-off-by: Cole Lightfighter <cole@onicsla.bz>
The commands handler must not be destroyed before the config
object, or we'll be accessing freed memory.
An earlier attempt at using boost::shared_ptr to control object
lifetime turned out to be very invasive, though would be a
better solution in theory.
- internal nullptr checks
- prevent modifications to network_address (shallow copy issues)
- automagically works with any type containing interface functions
- removed fnv1a hashing
- ipv4_network_address now flattened with no base class
6137a0b9 blockchain: reject unsorted ins and outs from v7 (moneromooo-monero)
16afab90 core: sort ins and outs key key image and public key, respectively (moneromooo-monero)
0c36b9f9 common: add apply_permutation file and function (moneromooo-monero)
It was always returning true, and could not be foreseen to
usefully return errors in the future. This silences CID 162652
as well as saves some checking code in a few places.
And optimize import startup:
Remember start_height position during initial count_blocks pass
to avoid having to reread entire file again to arrive at start_height
If monerod is started with default sync mode, set it to SAFE after
synchronization completes. Set it back to FAST if synchronization
restarts (e.g. because another peer has a longer blockchain).
If monerod is started with an explicit sync mode, none of this
automation takes effect.
Add get_fork_version and add_ideal_fork_version to core so
cryptonote_protocol does not have to need the Blockchain
class directly, as it's not in its dependencies, and add
those to the fake core classes in tests too.
A block queue is now placed between block download and
block processing. Blocks are now requested only from one
peer (unless starved).
Includes a new sync_info coommand.
Existing tests: block, transaction, signature, cold outputs,
cold transaction.
Data for these is in tests/data/fuzz.
A convenience shell script is in contrib/fuzz_testing/fuzz.sh, eg:
contrib/fuzz_testing/fuzz.sh signature
The fuzzer will run indefinitely, ^C to stop.
Fuzzing is currently supported for GCC only. I can't get CLANG
to build Monero here as it dies on some system headers, so if
someone wants to make it work on both, that'd be great.
In particular, the __AFL_LOOP construct should be made to work
so that a given run can fuzz multiple inputs, as the C++ load
time is substantial.
- Performance improvements
- Added `span` for zero-copy pointer+length arguments
- Added `std::ostream` overload for direct writing to output buffers
- Removal of unused `string_tools::buff_to_hex`
Minimum mixin 4 and enforced ringct is moved from v5 to v6.
v5 is now used for an increased minimum block size (from 60000
to 300000) to cater for larger typical/minimum transaction size.
The fee algorithm is also changed to decrease the base per kB
fee, and add a cheap tier for those transactions which we do
not care if they get delayed (or even included in a block).
a427235e core: add a missing newline on a string to be logged (moneromooo-monero)
b6a2230e unit_tests: fix minor blockchain_db regression (moneromooo-monero)
c488eca5 hardfork: tone down some logs (moneromooo-monero)
5adcb5a4 tx_pool: add a debug message when adding a tx to the pool (moneromooo-monero)
9faef1f8 cryptonote_protocol: misc fluffy block fixes (moneromooo-monero)
7403e56f performance_tests: report small time per call in microseconds (moneromooo-monero)
cadada2d performance_tests: add tests for sc_reduce32 and cn_fast_hash (moneromooo-monero)
962c72b6 performance_tests: initialize logging at startup (moneromooo-monero)
- fix wrong block being used when a new block is received between
a node elaying a fluffy block and sending a new fluffy block
with txes a peer did not have
- misc a neverending ping pong requesting the same missing txids
when a new block is received in the meantime, causing the top
block to not be the one we need
- send the original fluffy block message block height when sending
a new fluffy block, not the current top height, which might
have been updated since
- avoid sending back the whole block blob when asking for txes,
send only the hash instead
- plus misc cleanup and additional debugging logs
In simple terms, add_subdirectory() is replaced with ExternalProject_Add().
This change is inspired by https://crascit.com/2015/07/25/cmake-gtest/
with one difference, no download, using the source we already have.
Before this change, make debug-test must be preceded by make clean.
Otherwise, a subsequent build would be polluted by cmake options made
by tests/gtest/.
Also removed the changed compiler flags. My test build did not have
the affected warnings.
3ae79a59 core: set missing verifivation_failed flag when rejecting a tx (moneromooo-monero)
ea6549e9 core_tests: decrease trace level from trace to debug (moneromooo-monero)
- http_simple_client now uses std::chrono for timeouts
- http_simple_client accepts timeouts per connect / invoke call
- shortened names of epee http invoke functions
- invoke command functions only take relative path, connection
is not automatically performed
This replaces the epee and data_loggers logging systems with
a single one, and also adds filename:line and explicit severity
levels. Categories may be defined, and logging severity set
by category (or set of categories). epee style 0-4 log level
maps to a sensible severity configuration. Log files now also
rotate when reaching 100 MB.
To select which logs to output, use the MONERO_LOGS environment
variable, with a comma separated list of categories (globs are
supported), with their requested severity level after a colon.
If a log matches more than one such setting, the last one in
the configuration string applies. A few examples:
This one is (mostly) silent, only outputting fatal errors:
MONERO_LOGS=*:FATAL
This one is very verbose:
MONERO_LOGS=*:TRACE
This one is totally silent (logwise):
MONERO_LOGS=""
This one outputs all errors and warnings, except for the
"verify" category, which prints just fatal errors (the verify
category is used for logs about incoming transactions and
blocks, and it is expected that some/many will fail to verify,
hence we don't want the spam):
MONERO_LOGS=*:WARNING,verify:FATAL
Log levels are, in decreasing order of priority:
FATAL, ERROR, WARNING, INFO, DEBUG, TRACE
Subcategories may be added using prefixes and globs. This
example will output net.p2p logs at the TRACE level, but all
other net* logs only at INFO:
MONERO_LOGS=*:ERROR,net*:INFO,net.p2p:TRACE
Logs which are intended for the user (which Monero was using
a lot through epee, but really isn't a nice way to go things)
should use the "global" category. There are a few helper macros
for using this category, eg: MGINFO("this shows up by default")
or MGINFO_RED("this is red"), to try to keep a similar look
and feel for now.
Existing epee log macros still exist, and map to the new log
levels, but since they're used as a "user facing" UI element
as much as a logging system, they often don't map well to log
severities (ie, a log level 0 log may be an error, or may be
something we want the user to see, such as an important info).
In those cases, I tried to use the new macros. In other cases,
I left the existing macros in. When modifying logs, it is
probably best to switch to the new macros with explicit levels.
The --log-level options and set_log commands now also accept
category settings, in addition to the epee style log levels.
3ff54bdd Check for correct thread before ending batch transaction (Howard Chu)
eaf8470b Must wait for previous batch to finish before starting new one (Howard Chu)
c903c554 Don't cache block height, always get from DB (Howard Chu)
eb1fb601 Tweak default db-sync-mode to fast:async:1 (Howard Chu)
0693cff9 Use batch transactions when syncing (Howard Chu)
If a checksum word is present, language detection would use
just the word prefixes. However, a set of word prefixes may
be found in more than one language, and so the wrong language
may be found first, which could then fail the checksum, since
the check may be done with a different unique prefix length
from the one it was created from.
We now make a checksum test when we we detect a language from
prefixes only, to make sure we have the correct one.
