This converts the transaction type and version to scoped enum, giving
type safety and making the tx type assignment less error prone because
there is no implicit conversion or comparison with raw integers that has
to be worried about.
This ends up converting any use of `cryptonote::transaction::type_xyz`
to `cryptonote::transaction::txtype::xyz`. For version, names like
`transaction::version_v4` become `cryptonote::txversion::v4_tx_types`.
This also allows/includes various other simplifications related to or
enabled by this change:
- handle `is_deregister` dynamically in serialization code (setting
`type::standard` or `type::deregister` rather than using a
version-determined union)
- `get_type()` is no longer needed with the above change: it is now
much simpler to directly access `type` which will always have the
correct value (even for v2 or v3 transaction types). And though there
was an assertion on the enum value, `get_type()` was being used only
sporadically: many places accessed `.type` directly.
- the old unscoped enum didn't have a type but was assumed castable
to/from `uint16_t`, which technically meant there was potential
undefined behaviour when deserializing any type values >= 8.
- tx type range checks weren't being done in all serialization paths;
they are now. Because `get_type()` was not used everywhere (lots of
places simply accessed `.type` directory) these might not have been
caught.
- `set_type()` is not needed; it was only being used in a single place
(wallet2.cpp) and only for v4 txes, so the version protection code was
never doing anything.
- added a std::ostream << operator for the enum types so that they can be
output with `<< tx_type <<` rather than needing to wrap it in
`type_to_string(tx_type)` everywhere. For the versions, you get the
annotated version string (e.g. 4_tx_types) rather than just the number
4.
The change made for v2 broke v1, and we have no way to know which
version we're serializing here. However, since we don't actually
care about space savings in this case, we continue serialiazing
both mask and amount.
The change made for v2 broke v1, and we have no way to know which
version we're serializing here. However, since we don't actually
care about space savings in this case, we continue serialiazing
both mask and amount.
* Remove dead branches in hot-path check_tx_inputs
Also renames #define for mixins to better match naming convention
* Shuffle around some more code into common branches
* Fix min/max tx version rules, since there 1 tx v2 on v9 fork
* First draft infinite staking implementation
* Actually generate the right key image and expire appropriately
* Add framework to lock key images after expiry
* Return locked key images for nodes, add request unlock option
* Introduce transaction types for key image unlock
* Update validation steps to accept tx types, key_image_unlock
* Add mapping for lockable key images to amounts
* Change inconsistent naming scheme of contributors
* Create key image unlock transaction type and process it
* Update tx params to allow v4 types and as a result construct_tx*
* Fix some serialisation issues not sending all the information
* Fix dupe tx extra tag causing incorrect deserialisation
* Add warning comments
* Fix key image unlocks parsing error
* Simplify key image proof checks
* Fix rebase errors
* Correctly calculate the key image unlock times
* Blacklist key image on deregistration
* Serialise key image blacklist
* Rollback blacklisted key images
* Fix expiry logic error
* Disallow requesting stake unlock if already unlocked client side
* Add double spend checks for key image unlocks
* Rename get_staking_requirement_lock_blocks
To staking_initial_num_lock_blocks
* Begin modifying output selection to not use locked outputs
* Modify output selection to avoid locked/blacklisted key images
* Cleanup and undoing some protocol breakages
* Simplify expiration of nodes
* Request unlock schedules entire node for expiration
* Fix off by one in expiring nodes
* Undo expiring code for pre v10 nodes
* Fix RPC returning register as unlock height and not checking 0
* Rename key image unlock height const
* Undo testnet hardfork debug changes
* Remove is_type for get_type, fix missing var rename
* Move serialisable data into public namespace
* Serialise tx types properly
* Fix typo in no service node known msg
* Code review
* Fix == to >= on serialising tx type
* Code review 2
* Fix tests and key image unlock
* Add additional test, fix assert
* Remove debug code in wallet
* Fix merge dev problem
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
