Commit graph

30 commits

Author SHA1 Message Date
moneromooo-monero
01cc978722
ringct: remove an unnecessary scalarmultBase in zeroCommit 2018-06-06 10:14:36 +01:00
Edward Betts
fbcc91c2a4 Correct spelling mistakes. 2018-03-05 17:00:40 +00:00
cslashm
e745c1e38d Code modifications to integrate Ledger HW device into monero-wallet-cli.
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.
2018-03-04 12:54:53 +01:00
Riccardo Spagni
86da46e224
Merge pull request #3151
ab2e9953 unit_tests: do not ASSERT_TRUE(decodeRct(...)) (moneromooo-monero)
2018-01-27 17:25:55 -08:00
xmr-eric
18216f19dd Update 2018 copyright 2018-01-26 10:03:20 -05:00
moneromooo-monero
ab2e9953b4
unit_tests: do not ASSERT_TRUE(decodeRct(...))
decodeRct returns the amount, which may be zero
2018-01-18 13:55:51 +00:00
moneromooo-monero
4c313324b1
Add N/N multisig tx generation and signing
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
2017-12-17 16:11:57 +00:00
moneromooo-monero
383ff4f689
remove "using namespace std" from headers
It's nasty, and actually breaks on Solaris, where if.h fails to
build due to:

  struct map *if_memmap;
2017-11-14 16:56:10 +00:00
Lee Clagett
4a8f96f95d Improvements for epee binary to hex functions:
- 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`
2017-04-11 16:35:00 -04:00
Riccardo Spagni
c3599fa7b9
update copyright year, fix occasional lack of newline at line end 2017-02-21 19:38:18 +02:00
luigi1111
46a0dcc1d2
ringct: luigi1111's changes to fix and speedup Borromean sigs 2016-12-04 21:54:16 +00:00
Shen Noether
76958fc75a
ringct: switch to Borromean signatures 2016-12-04 21:54:11 +00:00
moneromooo-monero
ffd8c41f36
ringct: check the size of amount_keys is the same as destinations 2016-10-29 13:33:48 +01:00
moneromooo-monero
d4b62a1e29
rct amount key modified as per luigi1111's recommendations
This allows the key to be not the same for two outputs sent to
the same address (eg, if you pay yourself, and also get change
back). Also remove the key amounts lists and return parameters
since we don't actually generate random ones, so we don't need
to save them as we can recalculate them when needed if we have
the correct keys.
2016-08-28 21:30:19 +01:00
moneromooo-monero
93f5c625f0
rct: rework v2 txes into prunable and non prunable data
Nothing is pruned, but this allows easier changes later.
2016-08-28 21:30:18 +01:00
moneromooo-monero
d93746b6d3
rct: rework the verification preparation process
The whole rct data apart from the MLSAGs is now included in
the signed message, to avoid malleability issues.

Instead of passing the data that's not serialized as extra
parameters to the verification API, the transaction is modified
to fill all that information. This means the transaction can
not be const anymore, but it cleaner in other ways.
2016-08-28 21:30:16 +01:00
moneromooo-monero
9b70856ccb
rct: make the amount key derivable by a third party with the tx key
Scheme design from luigi1114.
2016-08-28 21:29:46 +01:00
moneromooo-monero
e06faefde4
tests: add basic tests for simple rct api 2016-08-28 21:29:22 +01:00
moneromooo-monero
a4d4d6194b
integrate simple rct api 2016-08-28 21:29:20 +01:00
moneromooo-monero
6d0e47148b
rct: add the tx prefix hash into the MLSAG
to protect the non-signatures parts of the tx from tampering.
2016-08-28 21:28:58 +01:00
moneromooo-monero
20e50ec7f7
ringct: do not serialize what can be reconstructed
The mixRing (output keys and commitments) and II fields (key images)
can be reconstructed from vin data.
This saves some modest amount of space in the tx.
2016-08-28 21:28:55 +01:00
moneromooo-monero
161551e13b
tests: test for ringct rctSig data sizes
ie, more data or less data than expected in various fields
2016-08-28 21:28:42 +01:00
moneromooo-monero
54f7429cf6
ringct: allow no outputs, and add tests for this and fees 2016-08-28 21:28:27 +01:00
Shen Noether
f8c04ad94f
ringct: txn fee stuff 2016-08-28 21:28:23 +01:00
Shen Noether
53cdf4df5e
tests: new ringct test for checking H2 values
Ported from Shen's RingCT repo
2016-08-28 21:28:01 +01:00
moneromooo-monero
720ac85553
tests: zero inputs/outputs are in fact supposed to be accepted 2016-08-28 21:27:52 +01:00
moneromooo-monero
84948eabae
ringct: add a test for prooveRange being non deterministic 2016-08-28 21:27:50 +01:00
moneromooo-monero
700248f59e
tests: more ringct range proof tests 2016-08-28 21:27:43 +01:00
moneromooo-monero
57779abe27
tests: add some more ringct building block tests 2016-08-28 21:27:26 +01:00
moneromooo-monero
2d6303fb2c
tests: add Shen Noether's basic ringct tests 2016-08-28 21:27:19 +01:00