- Remove implicit `operator bool` from ec_point/public_key/etc. which
was causing all sorts of implicit conversion mess and bugs.
- Change ec_point/public_key/etc. to use a `std::array<unsigned char,
32>` (via a base type) rather than a C-array of char that has to be
reinterpret_cast<>'ed all over the place.
- Add methods to ec_point/public_key/etc. that make it work more like a
container of bytes (`.data()`, `.size()`, `operator[]`, `begin()`,
`end()`).
- Make a generic `crypto::null<T>` that is a constexpr all-0 `T`, rather
than the mishmash `crypto::null_hash`, crypto::null_pkey,
crypto:#️⃣:null(), and so on.
- Replace three metric tons of `crypto::hash blahblah =
crypto::null_hash;` with the much simpler `crypto::hash blahblah{};`,
because there's no need to make a copy of a null hash in all these
cases. (Likewise for a few other null_whatevers).
- Remove a whole bunch of `if (blahblah == crypto::null_hash)` and `if
(blahblah != crypto::null_hash)` with the more concise `if
(!blahblah)` and `if (blahblah)` (which are fine via the newly
*explicit* bool conversion operators).
- `crypto::signature` becomes a 64-byte container (as above) but with
`c()` and `r()` to get the c() and r() data pointers. (Previously
`.c` and `.r` were `ec_scalar`s).
- Delete with great prejudice CRYPTO_MAKE_COMPARABLE and
CRYPTO_MAKE_HASHABLE and all the other utter trash in
`crypto/generic-ops.h`.
- De-inline functions in very common crypto/*.h files so that they don't
have to get compiled 300 times.
- Remove the disgusting include-a-C-header-inside-a-C++-namespace
garbage from some crypto headers trying to be both a C and *different*
C++ header at once.
- Remove the toxic, disgusting, shameful `operator&` on ec_scalar, etc.
that replace `&x` with `reinterpret_cast x into an unsigned char*`.
This was pure toxic waste.
- changed some `<<` outputs to fmt
- Random other small changes encountered while fixing everything that
cascaded out of the above changes.
This replaces the current epee logging system with our oxen::log
library. It replaces the easylogging library with spdlog, removes the
macros and replaces with functions and standardises how we call the
logs.
- De-static things that shouldn't be static (i.e. we don't need separate
copies of them in every compilation unit)
- Constexpr constants
- Replace confusing typedefs with usings
Also inline them into the header and simplify them.
Someone added functions for is_rct_whatever but used them almost
nowhere. This uses them (which would have saved a bunch of changes and
bugs in adding CLSAG in the first place).
loki_tx_builder fails for this test: it creates unserializable txes
because `vin` is too large. This was previously "passing" the test for
completely wrong reasons: the test produces transactions that fail to
serialize (triggering a "invalid mg_ss2 size: have 2, expected 3"
failure) while the point of the test was to produce serializable, but
invalid, transactions.
The failure wasn't being detected because the `tx_to_blob(t)` call in
`cryptonote_format_utils.cpp` would return a *partially filled*
serialization blob in case of serialization failure, which was
incredibly broken. `calculate_transaction_hash()` then was perfectly
happy to proceed with hashing this broken blob.
`tx_to_blob(t)` now returns an empty string on such a serialization
failure, and this made the test start failing because
`calculate_transaction_hash()` now fails.
This improves `calculate_transaction_hash()` a little more to add
earlier and more direct detection of such a failure, and fixes the test
by reverting it to the original Monero tx builder test code, which
creates the intended serializable-but-invalid transactions.
A huge amount of this is repetitive:
- `boost::get<T>(variant)` becomes `std::get<T>(variant)`
- `boost::get<T>(variant_ptr)` becomes `std::get_if<T>(variant_ptr)`
- `variant.type() == typeid(T)` becomes `std::holds_alternative<T>(variant)`
There are also some simplifications to visitors using simpler stl
visitors, or (simpler still) generic lambdas as visitors.
Also adds boost serialization serializers for std::variant and
std::optional.
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
- 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`
Easily fixed by moving a C++ header out of 'extern "C" {...}'.
When building with CC=clang CXX=clang++ make,
[ 21%] Building CXX object src/ringct/CMakeFiles/obj_ringct.dir/rctTypes.cpp.o
In file included from /home/tdprime/bitmonero/src/ringct/rctTypes.cpp:31:
In file included from /home/tdprime/bitmonero/src/ringct/rctTypes.h:43:
In file included from /home/tdprime/bitmonero/src/crypto/generic-ops.h:34:
/usr/bin/../lib/gcc/x86_64-linux-gnu/5.4.0/../../../../include/c++/5.4.0/cstring💯3: error: conflicting types for 'memchr'
memchr(void* __s, int __c, size_t __n)
^
/usr/include/string.h:92:14: note: previous declaration is here
extern void *memchr (const void *__s, int __c, size_t __n)
^
... and 4 more similar errors
Jason Rhinelander
Sean Darcy
Thomas Winget
moneromooo-monero
Sarang Noether
Tadeas Moravec
stoffu
Lee Clagett
einsteinsfool
kenshi84
Timothy D. Prime
Chris Vickio
moneroexamples
Shen Noether