def _gen_commitment(state: State, in_amount: int) -> tuple[Sc25519, Ge25519]:
"""
Computes Pedersen commitment - pseudo outs
Here is slight deviation from the original protocol.
We want that \\sum Alpha = \\sum A_{i,j} where A_{i,j} is a mask from range proof for output i, bit j.
Previously this was computed in such a way that Alpha_{last} = \\sum A{i,j} - \\sum_{i=0}^{last-1} Alpha
But we would prefer to compute commitment before range proofs so alphas are generated completely randomly
and the last A mask is computed in this special way.
Returns pseudo_out
"""
alpha = crypto.random_scalar()
state.sumpouts_alphas = crypto.sc_add(state.sumpouts_alphas, alpha)
return alpha, crypto.gen_commitment(alpha, in_amount)
def verify_bp(bp_proof, amounts, masks):
"""Verifies Bulletproof"""
from apps.monero.xmr import bulletproof as bp
if amounts:
bp_proof.V = []
for i in range(len(amounts)):
C = crypto.gen_commitment(masks[i], amounts[i])
crypto.scalarmult_into(C, C, crypto.sc_inv_eight())
bp_proof.V.append(crypto.encodepoint(C))
bpi = bp.BulletProofBuilder()
res = bpi.verify(bp_proof)
gc.collect()
return res
def _get_ecdh_info_and_out_pk(
state: State, tx_out_key: Ge25519, amount: int, mask: Sc25519,
amount_key: Sc25519) -> Tuple[bytes, bytes, bytes]:
"""
Calculates the Pedersen commitment C = aG + bH and returns it as CtKey.
Also encodes the two items - `mask` and `amount` - into ecdh info,
so the recipient is able to reconstruct the commitment.
"""
out_pk_dest = crypto.encodepoint(tx_out_key)
out_pk_commitment = crypto.encodepoint(crypto.gen_commitment(mask, amount))
crypto.sc_add_into(state.sumout, state.sumout, mask)
ecdh_info = _ecdh_encode(amount, crypto.encodeint(amount_key))
# Manual ECDH info serialization
ecdh_info_bin = _serialize_ecdh(ecdh_info)
gc.collect()
return out_pk_dest, out_pk_commitment, ecdh_info_bin
def _get_ecdh_info_and_out_pk(state: State, tx_out_key, amount, mask,
amount_key):
"""
Calculates the Pedersen commitment C = aG + bH and returns it as CtKey.
Also encodes the two items - `mask` and `amount` - into ecdh info,
so the recipient is able to reconstruct the commitment.
"""
out_pk_dest = crypto.encodepoint(tx_out_key)
out_pk_commitment = crypto.encodepoint(crypto.gen_commitment(mask, amount))
crypto.sc_add_into(state.sumout, state.sumout, mask)
# masking of mask and amount
ecdh_info = _ecdh_encode(mask, amount, crypto.encodeint(amount_key),
state.is_bulletproof_v2())
# Manual ECDH info serialization
ecdh_info_bin = _serialize_ecdh(ecdh_info, state.is_bulletproof_v2())
gc.collect()
return out_pk_dest, out_pk_commitment, ecdh_info_bin
def _get_ecdh_info_and_out_pk(state: State, tx_out_key, amount, mask,
amount_key):
"""
Calculates the Pedersen commitment C = aG + bH and returns it as CtKey.
Also encodes the two items - `mask` and `amount` - into ecdh info,
so the recipient is able to reconstruct the commitment.
"""
out_pk_dest = crypto.encodepoint(tx_out_key)
out_pk_commitment = crypto.encodepoint(crypto.gen_commitment(mask, amount))
state.sumout = crypto.sc_add(state.sumout, mask)
state.output_sk_masks.append(mask)
# masking of mask and amount
ecdh_info = _ecdh_encode(mask, amount, crypto.encodeint(amount_key))
# Manual ECDH info serialization
ecdh_info_bin = bytearray(64)
utils.memcpy(ecdh_info_bin, 0, ecdh_info.mask, 0, 32)
utils.memcpy(ecdh_info_bin, 32, ecdh_info.amount, 0, 32)
gc.collect()
return out_pk_dest, out_pk_commitment, ecdh_info_bin
async def sign_input(
state: State,
src_entr: MoneroTransactionSourceEntry,
vini_bin: bytes,
vini_hmac: bytes,
pseudo_out: bytes,
pseudo_out_hmac: bytes,
pseudo_out_alpha_enc: bytes,
spend_enc: bytes,
orig_idx: int,
) -> MoneroTransactionSignInputAck:
"""
:param state: transaction state
:param src_entr: Source entry
:param vini_bin: tx.vin[i] for the transaction. Contains key image, offsets, amount (usually zero)
:param vini_hmac: HMAC for the tx.vin[i] as returned from Trezor
:param pseudo_out: Pedersen commitment for the current input, uses pseudo_out_alpha
as a mask. Only applicable for RCTTypeSimple.
:param pseudo_out_hmac: HMAC for pseudo_out
:param pseudo_out_alpha_enc: alpha mask used in pseudo_out, only applicable for RCTTypeSimple. Encrypted.
:param spend_enc: one time address spending private key. Encrypted.
:param orig_idx: original index of the src_entr before sorting (HMAC check)
:return: Generated signature MGs[i]
"""
await confirms.transaction_step(state, state.STEP_SIGN,
state.current_input_index + 1)
state.current_input_index += 1
if state.last_step not in (state.STEP_ALL_OUT, state.STEP_SIGN):
raise ValueError("Invalid state transition")
if state.current_input_index >= state.input_count:
raise ValueError("Invalid inputs count")
if pseudo_out is None:
raise ValueError("SimpleRCT requires pseudo_out but none provided")
if pseudo_out_alpha_enc is None:
raise ValueError(
"SimpleRCT requires pseudo_out's mask but none provided")
input_position = (state.source_permutation[state.current_input_index]
if state.client_version <= 1 else orig_idx)
mods = utils.unimport_begin()
# Check input's HMAC
from apps.monero.signing import offloading_keys
vini_hmac_comp = await offloading_keys.gen_hmac_vini(
state.key_hmac, src_entr, vini_bin, input_position)
if not crypto.ct_equals(vini_hmac_comp, vini_hmac):
raise ValueError("HMAC is not correct")
# Key image sorting check - permutation correctness
cur_ki = offloading_keys.get_ki_from_vini(vini_bin)
if state.current_input_index > 0 and state.last_ki <= cur_ki:
raise ValueError("Key image order invalid")
state.last_ki = cur_ki if state.current_input_index < state.input_count else None
del (cur_ki, vini_bin, vini_hmac, vini_hmac_comp)
gc.collect()
state.mem_trace(1, True)
from apps.monero.xmr.crypto import chacha_poly
pseudo_out_alpha = crypto.decodeint(
chacha_poly.decrypt_pack(
offloading_keys.enc_key_txin_alpha(state.key_enc, input_position),
bytes(pseudo_out_alpha_enc),
))
# Last pseudo_out is recomputed so mask sums hold
if input_position + 1 == state.input_count:
# Recompute the lash alpha so the sum holds
state.mem_trace("Correcting alpha")
alpha_diff = crypto.sc_sub(state.sumout, state.sumpouts_alphas)
crypto.sc_add_into(pseudo_out_alpha, pseudo_out_alpha, alpha_diff)
pseudo_out_c = crypto.gen_commitment(pseudo_out_alpha,
state.input_last_amount)
else:
if input_position + 1 == state.input_count:
utils.ensure(crypto.sc_eq(state.sumpouts_alphas, state.sumout),
"Sum eq error")
# both pseudo_out and its mask were offloaded so we need to
# validate pseudo_out's HMAC and decrypt the alpha
pseudo_out_hmac_comp = crypto.compute_hmac(
offloading_keys.hmac_key_txin_comm(state.key_hmac, input_position),
pseudo_out,
)
if not crypto.ct_equals(pseudo_out_hmac_comp, pseudo_out_hmac):
raise ValueError("HMAC is not correct")
pseudo_out_c = crypto.decodepoint(pseudo_out)
state.mem_trace(2, True)
# Spending secret
spend_key = crypto.decodeint(
chacha_poly.decrypt_pack(
offloading_keys.enc_key_spend(state.key_enc, input_position),
bytes(spend_enc),
))
del (
offloading_keys,
chacha_poly,
pseudo_out,
pseudo_out_hmac,
pseudo_out_alpha_enc,
spend_enc,
)
utils.unimport_end(mods)
state.mem_trace(3, True)
# Basic setup, sanity check
from apps.monero.xmr.serialize_messages.tx_ct_key import CtKey
index = src_entr.real_output
input_secret_key = CtKey(spend_key, crypto.decodeint(src_entr.mask))
# Private key correctness test
utils.ensure(
crypto.point_eq(
crypto.decodepoint(
src_entr.outputs[src_entr.real_output].key.dest),
crypto.scalarmult_base(input_secret_key.dest),
),
"Real source entry's destination does not equal spend key's",
)
utils.ensure(
crypto.point_eq(
crypto.decodepoint(
src_entr.outputs[src_entr.real_output].key.commitment),
crypto.gen_commitment(input_secret_key.mask, src_entr.amount),
),
"Real source entry's mask does not equal spend key's",
)
state.mem_trace(4, True)
from apps.monero.xmr import mlsag
mg_buffer = []
ring_pubkeys = [x.key for x in src_entr.outputs if x]
utils.ensure(len(ring_pubkeys) == len(src_entr.outputs), "Invalid ring")
del src_entr
state.mem_trace(5, True)
if state.hard_fork and state.hard_fork >= 13:
state.mem_trace("CLSAG")
mlsag.generate_clsag_simple(
state.full_message,
ring_pubkeys,
input_secret_key,
pseudo_out_alpha,
pseudo_out_c,
index,
mg_buffer,
)
else:
mlsag.generate_mlsag_simple(
state.full_message,
ring_pubkeys,
input_secret_key,
pseudo_out_alpha,
pseudo_out_c,
index,
mg_buffer,
)
del (CtKey, input_secret_key, pseudo_out_alpha, mlsag, ring_pubkeys)
state.mem_trace(6, True)
from trezor.messages.MoneroTransactionSignInputAck import (
MoneroTransactionSignInputAck, )
# Encrypt signature, reveal once protocol finishes OK
if state.client_version >= 3:
utils.unimport_end(mods)
state.mem_trace(7, True)
mg_buffer = _protect_signature(state, mg_buffer)
state.mem_trace(8, True)
state.last_step = state.STEP_SIGN
return MoneroTransactionSignInputAck(
signature=mg_buffer, pseudo_out=crypto.encodepoint(pseudo_out_c))
async def sign_input(
state: State,
src_entr: MoneroTransactionSourceEntry,
vini_bin: bytes,
vini_hmac: bytes,
pseudo_out: bytes,
pseudo_out_hmac: bytes,
pseudo_out_alpha_enc: bytes,
spend_enc: bytes,
):
"""
:param state: transaction state
:param src_entr: Source entry
:param vini_bin: tx.vin[i] for the transaction. Contains key image, offsets, amount (usually zero)
:param vini_hmac: HMAC for the tx.vin[i] as returned from Trezor
:param pseudo_out: Pedersen commitment for the current input, uses pseudo_out_alpha
as a mask. Only applicable for RCTTypeSimple.
:param pseudo_out_hmac: HMAC for pseudo_out
:param pseudo_out_alpha_enc: alpha mask used in pseudo_out, only applicable for RCTTypeSimple. Encrypted.
:param spend_enc: one time address spending private key. Encrypted.
:return: Generated signature MGs[i]
"""
await confirms.transaction_step(state, state.STEP_SIGN,
state.current_input_index + 1)
state.current_input_index += 1
if state.current_input_index >= state.input_count:
raise ValueError("Invalid inputs count")
if pseudo_out is None:
raise ValueError("SimpleRCT requires pseudo_out but none provided")
if pseudo_out_alpha_enc is None:
raise ValueError(
"SimpleRCT requires pseudo_out's mask but none provided")
input_position = state.source_permutation[state.current_input_index]
mods = utils.unimport_begin()
# Check input's HMAC
from apps.monero.signing import offloading_keys
vini_hmac_comp = await offloading_keys.gen_hmac_vini(
state.key_hmac, src_entr, vini_bin, input_position)
if not crypto.ct_equals(vini_hmac_comp, vini_hmac):
raise ValueError("HMAC is not correct")
gc.collect()
state.mem_trace(1, True)
from apps.monero.xmr.crypto import chacha_poly
pseudo_out_alpha = crypto.decodeint(
chacha_poly.decrypt_pack(
offloading_keys.enc_key_txin_alpha(state.key_enc, input_position),
bytes(pseudo_out_alpha_enc),
))
# Last pseud_out is recomputed so mask sums hold
if state.is_det_mask() and input_position + 1 == state.input_count:
# Recompute the lash alpha so the sum holds
state.mem_trace("Correcting alpha")
alpha_diff = crypto.sc_sub(state.sumout, state.sumpouts_alphas)
crypto.sc_add_into(pseudo_out_alpha, pseudo_out_alpha, alpha_diff)
pseudo_out_c = crypto.gen_commitment(pseudo_out_alpha,
state.input_last_amount)
else:
if input_position + 1 == state.input_count:
utils.ensure(crypto.sc_eq(state.sumpouts_alphas, state.sumout),
"Sum eq error")
# both pseudo_out and its mask were offloaded so we need to
# validate pseudo_out's HMAC and decrypt the alpha
pseudo_out_hmac_comp = crypto.compute_hmac(
offloading_keys.hmac_key_txin_comm(state.key_hmac, input_position),
pseudo_out,
)
if not crypto.ct_equals(pseudo_out_hmac_comp, pseudo_out_hmac):
raise ValueError("HMAC is not correct")
pseudo_out_c = crypto.decodepoint(pseudo_out)
state.mem_trace(2, True)
# Spending secret
spend_key = crypto.decodeint(
chacha_poly.decrypt_pack(
offloading_keys.enc_key_spend(state.key_enc, input_position),
bytes(spend_enc),
))
del (
offloading_keys,
chacha_poly,
pseudo_out,
pseudo_out_hmac,
pseudo_out_alpha_enc,
spend_enc,
)
utils.unimport_end(mods)
state.mem_trace(3, True)
from apps.monero.xmr.serialize_messages.ct_keys import CtKey
# Basic setup, sanity check
index = src_entr.real_output
input_secret_key = CtKey(dest=spend_key,
mask=crypto.decodeint(src_entr.mask))
kLRki = None # for multisig: src_entr.multisig_kLRki
# Private key correctness test
utils.ensure(
crypto.point_eq(
crypto.decodepoint(
src_entr.outputs[src_entr.real_output].key.dest),
crypto.scalarmult_base(input_secret_key.dest),
),
"Real source entry's destination does not equal spend key's",
)
utils.ensure(
crypto.point_eq(
crypto.decodepoint(
src_entr.outputs[src_entr.real_output].key.commitment),
crypto.gen_commitment(input_secret_key.mask, src_entr.amount),
),
"Real source entry's mask does not equal spend key's",
)
state.mem_trace(4, True)
from apps.monero.xmr import mlsag
mg_buffer = []
ring_pubkeys = [x.key for x in src_entr.outputs]
del src_entr
mlsag.generate_mlsag_simple(
state.full_message,
ring_pubkeys,
input_secret_key,
pseudo_out_alpha,
pseudo_out_c,
kLRki,
index,
mg_buffer,
)
del (input_secret_key, pseudo_out_alpha, mlsag, ring_pubkeys)
state.mem_trace(5, True)
from trezor.messages.MoneroTransactionSignInputAck import (
MoneroTransactionSignInputAck, )
return MoneroTransactionSignInputAck(
signature=mg_buffer, pseudo_out=crypto.encodepoint(pseudo_out_c))
async def sign_input(
state: State,
src_entr: MoneroTransactionSourceEntry,
vini_bin: bytes,
vini_hmac: bytes,
pseudo_out: bytes,
pseudo_out_hmac: bytes,
pseudo_out_alpha_enc: bytes,
spend_enc: bytes,
):
"""
:param state: transaction state
:param src_entr: Source entry
:param vini_bin: tx.vin[i] for the transaction. Contains key image, offsets, amount (usually zero)
:param vini_hmac: HMAC for the tx.vin[i] as returned from Trezor
:param pseudo_out: Pedersen commitment for the current input, uses pseudo_out_alpha
as a mask. Only applicable for RCTTypeSimple.
:param pseudo_out_hmac: HMAC for pseudo_out
:param pseudo_out_alpha_enc: alpha mask used in pseudo_out, only applicable for RCTTypeSimple. Encrypted.
:param spend_enc: one time address spending private key. Encrypted.
:return: Generated signature MGs[i]
"""
from apps.monero.signing import offloading_keys
await confirms.transaction_step(state.ctx, state.STEP_SIGN,
state.current_input_index + 1,
state.input_count)
state.current_input_index += 1
if state.current_input_index >= state.input_count:
raise ValueError("Invalid inputs count")
if state.rct_type == RctType.Simple and pseudo_out is None:
raise ValueError("SimpleRCT requires pseudo_out but none provided")
if state.rct_type == RctType.Simple and pseudo_out_alpha_enc is None:
raise ValueError(
"SimpleRCT requires pseudo_out's mask but none provided")
if state.current_input_index >= 1 and not state.rct_type == RctType.Simple:
raise ValueError("Two and more inputs must imply SimpleRCT")
input_position = state.source_permutation[state.current_input_index]
# Check input's HMAC
vini_hmac_comp = await offloading_keys.gen_hmac_vini(
state.key_hmac, src_entr, vini_bin, input_position)
if not crypto.ct_equals(vini_hmac_comp, vini_hmac):
raise ValueError("HMAC is not correct")
gc.collect()
state.mem_trace(1)
if state.rct_type == RctType.Simple:
# both pseudo_out and its mask were offloaded so we need to
# validate pseudo_out's HMAC and decrypt the alpha
pseudo_out_hmac_comp = crypto.compute_hmac(
offloading_keys.hmac_key_txin_comm(state.key_hmac, input_position),
pseudo_out,
)
if not crypto.ct_equals(pseudo_out_hmac_comp, pseudo_out_hmac):
raise ValueError("HMAC is not correct")
gc.collect()
state.mem_trace(2)
from apps.monero.xmr.crypto import chacha_poly
pseudo_out_alpha = crypto.decodeint(
chacha_poly.decrypt_pack(
offloading_keys.enc_key_txin_alpha(state.key_enc,
input_position),
bytes(pseudo_out_alpha_enc),
))
pseudo_out_c = crypto.decodepoint(pseudo_out)
# Spending secret
from apps.monero.xmr.crypto import chacha_poly
from apps.monero.xmr.serialize_messages.ct_keys import CtKey
spend_key = crypto.decodeint(
chacha_poly.decrypt_pack(
offloading_keys.enc_key_spend(state.key_enc, input_position),
bytes(spend_enc),
))
gc.collect()
state.mem_trace(3)
# Basic setup, sanity check
index = src_entr.real_output
input_secret_key = CtKey(dest=spend_key,
mask=crypto.decodeint(src_entr.mask))
kLRki = None # for multisig: src_entr.multisig_kLRki
# Private key correctness test
utils.ensure(
crypto.point_eq(
crypto.decodepoint(
src_entr.outputs[src_entr.real_output].key.dest),
crypto.scalarmult_base(input_secret_key.dest),
),
"Real source entry's destination does not equal spend key's",
)
utils.ensure(
crypto.point_eq(
crypto.decodepoint(
src_entr.outputs[src_entr.real_output].key.commitment),
crypto.gen_commitment(input_secret_key.mask, src_entr.amount),
),
"Real source entry's mask does not equal spend key's",
)
gc.collect()
state.mem_trace(4)
from apps.monero.xmr import mlsag
if state.rct_type == RctType.Simple:
ring_pubkeys = [x.key for x in src_entr.outputs]
mg = mlsag.generate_mlsag_simple(
state.full_message,
ring_pubkeys,
input_secret_key,
pseudo_out_alpha,
pseudo_out_c,
kLRki,
index,
)
else:
# Full RingCt, only one input
txn_fee_key = crypto.scalarmult_h(state.fee)
ring_pubkeys = [[x.key] for x in src_entr.outputs]
mg = mlsag.generate_mlsag_full(
state.full_message,
ring_pubkeys,
[input_secret_key],
state.output_sk_masks,
state.output_pk_commitments,
kLRki,
index,
txn_fee_key,
)
gc.collect()
state.mem_trace(5)
# Encode
mgs = _recode_msg([mg])
gc.collect()
state.mem_trace(6)
from trezor.messages.MoneroTransactionSignInputAck import (
MoneroTransactionSignInputAck, )
return MoneroTransactionSignInputAck(
signature=serialize.dump_msg_gc(mgs[0], preallocate=488))
