New private/public key pairs for broadcasting alert messages
Implements #424
Fixes and integrates method of sending alerts as described by upstream here:
- https://gist.github.com/laanwj/0e689cfa37b52bcbbb44
To send an alert:
- Copy private keys into alertkeys.h.
- Modify alert parameters and message found in sendalert.cpp
- Build and run to send the alert e.g. ./zcashd -printtoconsole -sendalert
Tested and verified with local nodes on alpha 6 testnet.
Final changes to the circuit
* Remove [redundant](https://github.com/scipr-lab/libsnark/issues/37) bitness constraints that I pointed out in #908.
* The depth is increased from 20 to 29. I chose 29 because the QAP degree ends up being a power of two, which is probably going to be useful for the FFT in our MPC. (Closes#16)
If we're happy with depth 29 (over 268 million possible joinsplits), this will probably be the final change to the constraint system before 1.0.
The partition checking code was using chainActive timestamps
to detect partitioning; with headers-first syncing, it should use
(and with this pull request, does use) pIndexBestHeader timestamps.
Fixes issue #6251
Github-Pull: #6256
Rebased-From: 65b94545036ae6e38e79e9c7166a3ba1ddb83f66
Make it possible to opt-out of the centralized alert system by providing
an option `-noalerts` or `-alerts=0`. The default remains unchanged.
This is a gentler form of #6260, in which I went a bit overboard by
removing the alert system completely.
I intend to add this to the GUI options in another pull after this.
Github-Pull: #6274
Rebased-From: 02a6702a82a5b00e0e0351041dd3267308b7f319
In some corner cases, it may be possible for recent blocks to end up in
the same block file as much older blocks. Previously, the pruning code
would stop looking for files to remove upon first encountering a file
containing a block that cannot be pruned, now it will keep looking for
candidate files until the target is met and all other criteria are
satisfied.
This can result in a noncontiguous set of block files (by number) on
disk, which is fine except for during some reindex corner cases, so
make reindex preparation smarter such that we keep the data we can
actually use and throw away the rest. This allows pruning to work
correctly while downloading any blocks needed during the reindex.
Rebased-From: c257a8c9a6397eee40734b235a4fdcb8045aec91
Github-Pull: #6221
To protect privacy, do not use UPNP when a proxy is set. The user may
still specify -listen=1 to listen locally (for a hidden service), so
don't rely on this happening through -listen.
Fixes#2927.
86a5f4b Relocate calls to CheckDiskSpace (Alex Morcos)
67708ac Write block index more frequently than cache flushes (Pieter Wuille)
b3ed423 Cache tweak and logging improvements (Pieter Wuille)
fc684ad Use accurate memory for flushing decisions (Pieter Wuille)
046392d Keep track of memory usage in CCoinsViewCache (Pieter Wuille)
540629c Add memusage.h (Pieter Wuille)
Create a monitoring task that counts how many blocks have been found in the last four hours.
If very few or too many have been found, an alert is triggered.
"Very few" and "too many" are set based on a false positive rate of once every fifty years of constant running with constant hashing power, which works out to getting 5 or fewer or 48 or more blocks in four hours (instead of the average of 24).
Only one alert per day is triggered, so if you get disconnected from the network (or are being Sybil'ed) -alertnotify will be triggered after 3.5 hours but you won't get another -alertnotify for 24 hours.
Tested with a new unit test and by running on the main network with -debug=partitioncheck
Run test/test_bitcoin --log_level=message to see the alert messages:
WARNING: check your network connection, 3 blocks received in the last 4 hours (24 expected)
WARNING: abnormally high number of blocks generated, 60 blocks received in the last 4 hours (24 expected)
The -debug=partitioncheck debug.log messages look like:
ThreadPartitionCheck : Found 22 blocks in the last 4 hours
ThreadPartitionCheck : likelihood: 0.0777702