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.
If a pre-fork output is spent on both Monero and attack chain,
any post-fork output can be deduced to be a fake output, thereby
decreasing the effective ring size.
The segregate-per-fork-outputs option, on by default, allows
selecting only pre-fork outputs in this case, so that the same
ring can be used when spending it on the other side, which does
not decrease the effective ring size.
This is intended to be SET when intending to spend Monero on the
attack fork, and to be UNSET if not intending to spend Monero
on the attack fork (since it leaks the fact that the output being
spent is pre-fork).
If the user is not certain yet whether they will spend pre-fork
outputs on a key reusing fork, the key-reuse-mitigation2 option
should be SET instead.
If you use this option and intend to spend Monero on both forks,
then spend real Monero first.
This maps key images to rings, so that different forks can reuse
the rings by key image. This avoids revealing the real inputs like
would happen if two forks spent the same outputs with different
rings. This database is meant to be shared with all Monero forks
which don't bother making a new chain, putting users' privacy at
risk in the process. It is placed in a shared data directory by
default ($HOME/.shared-ringdb on UNIX like systems). You may
use --shared-ringdb-dir to override this location, and should
then do so for all Monero forks for them to share the database.
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.
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
- refactoring: proof generation/checking code was moved from simplewallet.cpp to wallet2.cpp
- allow an arbitrary message to be signed together with txid
- introduce two types (outbound & inbound) of tx proofs; with the same syntax, inbound is selected when <address> belongs to this wallet, outbound otherwise. see GitHub thread for more discussion
- wallet RPC: added get_tx_key, check_tx_key, get_tx_proof, check_tx_proof
- wallet API: moved WalletManagerImpl::checkPayment to Wallet::checkTxKey, added Wallet::getTxProof/checkTxProof
- get_tx_key/check_tx_key: handle additional tx keys by concatenating them into a single string
b7d6ec83 simplewallet: add (out of sync) or (no daemon) markers in the prompt (moneromooo-monero)
fa23a500 wallet2: add a is_synced function (moneromooo-monero)
f1307bbd node_rpc_proxy: add a proxy for target height (moneromooo-monero)
Asks user for all the data required to merge secret keys from multisig wallets into one master wallet, which then gets full control of the multisig wallet. The resulting wallet will be the same as any other regular wallet.
It sweeps all outputs below the given threshold
This is available via the existing sweep_all RPC, by setting
amount_threshold the desired amount (in atomic units)
With the change from the original transfer method to the new
algorithm, payments to the same destination were merged. It
seemed like a good idea, optimizing space. However, it is a
useful tool for people who want to split large outputs into
several smaller ones (ie, service providers making frequent
payments, and who do not like a large chunk of their balance
being locked for 10 blocks after each payment).
Default to off, which is a change from the previous behavior.
When a single input is enough to satisfy a transfer, the code would
previously try to add a second input, to match the "canonical" makeup
of a transaction with two inputs and two outputs. This would cause
wallets to slowly merge outputs till all the monero ends up in a
single output, which causes trouble when making two transactions
one after the other, since change is locked for 10 blocks, and an
increasing portion of the remaining balance would end up locked on
each transaction.
There are two new settings (min-output-count and min-output-value)
which can control when to stop adding such unneeded second outputs.
The idea is that small "dust" outputs will still get added, but
larger ones will not.
Enable with, eg:
set min-output-count 10
set min-output-value 30
to avoid using an unneeded second output of 30 monero or more, if
there would be less than 10 such outputs left.
This does not invalidate any other reason why such outputs would
be used (ie, when they're really needed to satisfy a transfer, or
when randomly picked in the normal course of selection). This may
be improved in the future.
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.
c2135082 simplewallet: add a show_transfer <txid> command (moneromooo-monero)
19c4041d wallet_rpc_server: new RPC call to get a transfer by txid (moneromooo-monero)
When passing around unsigned and signed transactions, outputs
and key images are passed along (outputs are passed along unsigned
transactions from the hot wallet to the cold wallet, key images
are passed along with signed transations from the cold wallet
to the hot wallet), to allow more user friendly syncing between
hot and cold wallets.
The intended use is to export outputs from a hot wallet, which
can scan incoming transfers from the network, and import them
in the cold wallet, which can't. The cold wallet can then compute
key images for those outputs, which can then be exported with
export_key_images, etc.
714ee99 Fix description for locked_transfer (Oyvind Kvanes)
71538f3 Rename to lockblocks and add max value (Oyvind Kvanes)
68ac060 Fix locked_transfer (Oyvind Kvanes)
7d020bd Add locked_transfer (Oyvind Kvanes)
d5f918a Revert transfer_main in simplewallet (Oyvind Kvanes)
3451963 Add motifications to test out locked_transfer (Oyvind Kvanes)
e5e6d88 Add more information to transaction in wallet (Oyvind Kvanes)
9b8a062 Make a small test change (Oyvind Kvanes)
This change adds the ability to create a new unsigned transaction
from a watch only wallet, and save it to a file. This file can
then be moved to another computer/VM where a cold wallet may load
it, sign it, and save it. That cold wallet does not need to have
a blockchain nor daemon. The signed transaction file can then be
moved back to the watch only wallet, which can load it and send
it to the daemon.
Two new simplewallet commands to use it:
sign_transfer (on the cold wallet)
submit_transfer (on the watch only wallet)
The transfer command used on a watch only wallet now writes an
unsigned transaction set in a file called 'unsigned_monero_tx'
instead of submitting the tx to the daemon as a normal wallet does.
The signed tx file is called 'signed_monero_tx'.
