mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
388 lines
16 KiB
Plaintext
388 lines
16 KiB
Plaintext
/**
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* @title Library to validate AZTEC zero-knowledge proofs
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* @author Zachary Williamson, AZTEC
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* @dev Don't include this as an internal library. This contract uses a static memory table to cache elliptic curve primitives and hashes.
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* Calling this internally from another function will lead to memory mutation and undefined behaviour.
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* The intended use case is to call this externally via `staticcall`. External calls to OptimizedAZTEC can be treated as pure functions as this contract contains no storage and makes no external calls (other than to precompiles)
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* Copyright Spilbury Holdings Ltd 2018. All rights reserved.
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* We will be releasing AZTEC as an open-source protocol that provides efficient transaction privacy for Ethereum.
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* This will include our bespoke AZTEC decentralized exchange, allowing for cross-asset transfers with full transaction privacy
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* and interopability with public decentralized exchanges.
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* Stay tuned for updates!
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*
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* Permission to use as test case in the Solidity compiler granted by the author:
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* https://github.com/ethereum/solidity/pull/5713#issuecomment-449042830
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**/
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{
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validateJoinSplit()
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// should not get here
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mstore(0x00, 404)
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revert(0x00, 0x20)
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function validateJoinSplit() {
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mstore(0x80, 7673901602397024137095011250362199966051872585513276903826533215767972925880) // h_x
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mstore(0xa0, 8489654445897228341090914135473290831551238522473825886865492707826370766375) // h_y
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let notes := add(0x04, calldataload(0x04))
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let m := calldataload(0x24)
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let n := calldataload(notes)
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let gen_order := 0x30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000001
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let challenge := mod(calldataload(0x44), gen_order)
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// validate m <= n
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if gt(m, n) { mstore(0x00, 404) revert(0x00, 0x20) }
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// recover k_{public} and calculate k_{public}
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let kn := calldataload(sub(calldatasize(), 0xc0))
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// add kn and m to final hash table
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mstore(0x2a0, caller())
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mstore(0x2c0, kn)
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mstore(0x2e0, m)
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kn := mulmod(sub(gen_order, kn), challenge, gen_order) // we actually want c*k_{public}
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hashCommitments(notes, n)
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let b := add(0x300, mul(n, 0x80))
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// Iterate over every note and calculate the blinding factor B_i = \gamma_i^{kBar}h^{aBar}\sigma_i^{-c}.
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// We use the AZTEC protocol pairing optimization to reduce the number of pairing comparisons to 1, which adds some minor alterations
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for { let i := 0 } lt(i, n) { i := add(i, 0x01) } {
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// Get the calldata index of this note
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let noteIndex := add(add(notes, 0x20), mul(i, 0xc0))
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let k
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let a := calldataload(add(noteIndex, 0x20))
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let c := challenge
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switch eq(add(i, 0x01), n)
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case 1 {
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k := kn
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// if all notes are input notes, invert k
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if eq(m, n) {
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k := sub(gen_order, k)
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}
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}
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case 0 { k := calldataload(noteIndex) }
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// Check this commitment is well formed...
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validateCommitment(noteIndex, k, a)
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// If i > m then this is an output note.
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// Set k = kx_j, a = ax_j, c = cx_j, where j = i - (m+1)
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switch gt(add(i, 0x01), m)
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case 1 {
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// before we update k, update kn = \sum_{i=0}^{m-1}k_i - \sum_{i=m}^{n-1}k_i
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kn := addmod(kn, sub(gen_order, k), gen_order)
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let x := mod(mload(0x00), gen_order)
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k := mulmod(k, x, gen_order)
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a := mulmod(a, x, gen_order)
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c := mulmod(challenge, x, gen_order)
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// calculate x_{j+1}
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mstore(0x00, keccak256(0x00, 0x20))
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}
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case 0 {
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// nothing to do here except update kn = \sum_{i=0}^{m-1}k_i - \sum_{i=m}^{n-1}k_i
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kn := addmod(kn, k, gen_order)
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}
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calldatacopy(0xe0, add(noteIndex, 0x80), 0x40)
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calldatacopy(0x20, add(noteIndex, 0x40), 0x40)
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mstore(0x120, sub(gen_order, c))
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mstore(0x60, k)
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mstore(0xc0, a)
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// Using call instead of staticcall here to make it work on all targets.
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let result := call(gas(), 7, 0, 0xe0, 0x60, 0x1a0, 0x40)
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result := and(result, call(gas(), 7, 0, 0x20, 0x60, 0x120, 0x40))
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result := and(result, call(gas(), 7, 0, 0x80, 0x60, 0x160, 0x40))
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result := and(result, call(gas(), 6, 0, 0x120, 0x80, 0x160, 0x40))
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result := and(result, call(gas(), 6, 0, 0x160, 0x80, b, 0x40))
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if eq(i, m) {
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mstore(0x260, mload(0x20))
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mstore(0x280, mload(0x40))
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mstore(0x1e0, mload(0xe0))
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mstore(0x200, sub(0x30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47, mload(0x100)))
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}
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if gt(i, m) {
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mstore(0x60, c)
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result := and(result, call(gas(), 7, 0, 0x20, 0x60, 0x220, 0x40))
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result := and(result, call(gas(), 6, 0, 0x220, 0x80, 0x260, 0x40))
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result := and(result, call(gas(), 6, 0, 0x1a0, 0x80, 0x1e0, 0x40))
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}
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if iszero(result) { mstore(0x00, 400) revert(0x00, 0x20) }
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b := add(b, 0x40) // increase B pointer by 2 words
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}
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if lt(m, n) {
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validatePairing(0x64)
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}
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let expected := mod(keccak256(0x2a0, sub(b, 0x2a0)), gen_order)
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if iszero(eq(expected, challenge)) {
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// No! Bad! No soup for you!
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mstore(0x00, 404)
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revert(0x00, 0x20)
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}
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// Great! All done. This is a valid proof so return ```true```
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mstore(0x00, 0x01)
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return(0x00, 0x20)
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}
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function validatePairing(t2) {
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let field_order := 0x30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47
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let t2_x_1 := calldataload(t2)
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let t2_x_2 := calldataload(add(t2, 0x20))
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let t2_y_1 := calldataload(add(t2, 0x40))
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let t2_y_2 := calldataload(add(t2, 0x60))
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// check provided setup pubkey is not zero or g2
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if or(or(or(or(or(or(or(
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iszero(t2_x_1),
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iszero(t2_x_2)),
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iszero(t2_y_1)),
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iszero(t2_y_2)),
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eq(t2_x_1, 0x1800deef121f1e76426a00665e5c4479674322d4f75edadd46debd5cd992f6ed)),
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eq(t2_x_2, 0x198e9393920d483a7260bfb731fb5d25f1aa493335a9e71297e485b7aef312c2)),
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eq(t2_y_1, 0x12c85ea5db8c6deb4aab71808dcb408fe3d1e7690c43d37b4ce6cc0166fa7daa)),
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eq(t2_y_2, 0x90689d0585ff075ec9e99ad690c3395bc4b313370b38ef355acdadcd122975b))
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{
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mstore(0x00, 400)
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revert(0x00, 0x20)
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}
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mstore(0x20, mload(0x1e0)) // sigma accumulator x
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mstore(0x40, mload(0x200)) // sigma accumulator y
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mstore(0x80, 0x1800deef121f1e76426a00665e5c4479674322d4f75edadd46debd5cd992f6ed)
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mstore(0x60, 0x198e9393920d483a7260bfb731fb5d25f1aa493335a9e71297e485b7aef312c2)
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mstore(0xc0, 0x12c85ea5db8c6deb4aab71808dcb408fe3d1e7690c43d37b4ce6cc0166fa7daa)
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mstore(0xa0, 0x90689d0585ff075ec9e99ad690c3395bc4b313370b38ef355acdadcd122975b)
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mstore(0xe0, mload(0x260)) // gamma accumulator x
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mstore(0x100, mload(0x280)) // gamma accumulator y
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mstore(0x140, t2_x_1)
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mstore(0x120, t2_x_2)
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mstore(0x180, t2_y_1)
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mstore(0x160, t2_y_2)
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let success := call(gas(), 8, 0, 0x20, 0x180, 0x20, 0x20)
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if or(iszero(success), iszero(mload(0x20))) {
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mstore(0x00, 400)
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revert(0x00, 0x20)
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}
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}
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function validateCommitment(note, k, a) {
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let gen_order := 0x30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000001
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let field_order := 0x30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47
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let gammaX := calldataload(add(note, 0x40))
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let gammaY := calldataload(add(note, 0x60))
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let sigmaX := calldataload(add(note, 0x80))
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let sigmaY := calldataload(add(note, 0xa0))
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if iszero(
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and(
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and(
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and(
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eq(mod(a, gen_order), a), // a is modulo generator order?
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gt(a, 1) // can't be 0 or 1 either!
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),
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and(
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eq(mod(k, gen_order), k), // k is modulo generator order?
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gt(k, 1) // and not 0 or 1
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)
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),
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and(
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eq( // y^2 ?= x^3 + 3
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addmod(mulmod(mulmod(sigmaX, sigmaX, field_order), sigmaX, field_order), 3, field_order),
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mulmod(sigmaY, sigmaY, field_order)
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),
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eq( // y^2 ?= x^3 + 3
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addmod(mulmod(mulmod(gammaX, gammaX, field_order), gammaX, field_order), 3, field_order),
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mulmod(gammaY, gammaY, field_order)
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)
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)
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)
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) {
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mstore(0x00, 400)
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revert(0x00, 0x20)
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}
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}
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function hashCommitments(notes, n) {
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for { let i := 0 } lt(i, n) { i := add(i, 0x01) } {
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let index := add(add(notes, mul(i, 0xc0)), 0x60)
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calldatacopy(add(0x300, mul(i, 0x80)), index, 0x80)
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}
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mstore(0x00, keccak256(0x300, mul(n, 0x80)))
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}
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}
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// ====
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// EVMVersion: >=istanbul
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// ----
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// step: fullSuite
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//
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// {
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// {
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// mstore(0x80, 7673901602397024137095011250362199966051872585513276903826533215767972925880)
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// mstore(0xa0, 8489654445897228341090914135473290831551238522473825886865492707826370766375)
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// let _1 := calldataload(0x04)
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// let notes := add(0x04, _1)
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// let m := calldataload(0x24)
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// let n := calldataload(notes)
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// let _2 := 0x30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000001
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// let challenge := mod(calldataload(0x44), _2)
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// if gt(m, n)
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// {
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// mstore(0x00, 404)
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// revert(0x00, 0x20)
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// }
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// let kn := calldataload(add(calldatasize(), not(191)))
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// mstore(0x2a0, caller())
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// mstore(0x2c0, kn)
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// mstore(0x2e0, m)
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// kn := mulmod(sub(_2, kn), challenge, _2)
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// hashCommitments(notes, n)
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// let b := add(0x300, shl(7, n))
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// let i := 0
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// for { } lt(i, n) { i := add(i, 0x01) }
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// {
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// let _3 := add(_1, mul(i, 0xc0))
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// let noteIndex := add(_3, 0x24)
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// let k := 0
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// let a := calldataload(add(_3, 0x44))
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// let c := challenge
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// let _4 := add(i, 0x01)
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// switch eq(_4, n)
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// case 1 {
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// k := kn
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// if eq(m, n) { k := sub(_2, kn) }
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// }
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// case 0 { k := calldataload(noteIndex) }
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// validateCommitment(noteIndex, k, a)
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// switch gt(_4, m)
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// case 1 {
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// kn := addmod(kn, sub(_2, k), _2)
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// let x := mod(mload(0), _2)
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// k := mulmod(k, x, _2)
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// a := mulmod(a, x, _2)
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// c := mulmod(challenge, x, _2)
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// mstore(0, keccak256(0, 0x20))
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// }
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// case 0 { kn := addmod(kn, k, _2) }
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// let _5 := 0x40
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// calldatacopy(0xe0, add(_3, 164), _5)
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// calldatacopy(0x20, add(_3, 100), _5)
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// let _6 := 0x120
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// mstore(_6, sub(_2, c))
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// let _7 := 0x60
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// mstore(_7, k)
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// mstore(0xc0, a)
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// let result := call(gas(), 7, 0, 0xe0, _7, 0x1a0, _5)
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// let result_1 := and(result, call(gas(), 7, 0, 0x20, _7, _6, _5))
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// let _8 := 0x160
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// let result_2 := and(result_1, call(gas(), 7, 0, 0x80, _7, _8, _5))
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// let result_3 := and(result_2, call(gas(), 6, 0, _6, 0x80, _8, _5))
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// result := and(result_3, call(gas(), 6, 0, _8, 0x80, b, _5))
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// if eq(i, m)
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// {
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// mstore(0x260, mload(0x20))
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// mstore(0x280, mload(_5))
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// mstore(0x1e0, mload(0xe0))
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// mstore(0x200, sub(0x30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47, mload(0x100)))
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// }
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// if gt(i, m)
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// {
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// mstore(_7, c)
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// let result_4 := and(result, call(gas(), 7, 0, 0x20, _7, 0x220, _5))
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// let result_5 := and(result_4, call(gas(), 6, 0, 0x220, 0x80, 0x260, _5))
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// result := and(result_5, call(gas(), 6, 0, 0x1a0, 0x80, 0x1e0, _5))
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// }
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// if iszero(result)
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// {
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// mstore(0, 400)
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// revert(0, 0x20)
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// }
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// b := add(b, _5)
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// }
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// if lt(m, n) { validatePairing(100) }
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// if iszero(eq(mod(keccak256(0x2a0, add(b, not(671))), _2), challenge))
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// {
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// mstore(0, 404)
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// revert(0, 0x20)
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// }
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// mstore(0, 0x01)
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// return(0, 0x20)
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// }
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// function validatePairing(t2)
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// {
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// let t2_x := calldataload(t2)
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// let _1 := 0x20
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// let t2_x_1 := calldataload(add(t2, _1))
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// let t2_y := calldataload(add(t2, 0x40))
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// let t2_y_1 := calldataload(add(t2, 0x60))
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// let _2 := 0x90689d0585ff075ec9e99ad690c3395bc4b313370b38ef355acdadcd122975b
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// let _3 := 0x12c85ea5db8c6deb4aab71808dcb408fe3d1e7690c43d37b4ce6cc0166fa7daa
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// let _4 := 0x198e9393920d483a7260bfb731fb5d25f1aa493335a9e71297e485b7aef312c2
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// let _5 := 0x1800deef121f1e76426a00665e5c4479674322d4f75edadd46debd5cd992f6ed
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// if or(or(or(or(or(or(or(iszero(t2_x), iszero(t2_x_1)), iszero(t2_y)), iszero(t2_y_1)), eq(t2_x, _5)), eq(t2_x_1, _4)), eq(t2_y, _3)), eq(t2_y_1, _2))
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// {
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// mstore(0x00, 400)
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// revert(0x00, _1)
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// }
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// mstore(_1, mload(0x1e0))
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// mstore(0x40, mload(0x200))
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// mstore(0x80, _5)
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// mstore(0x60, _4)
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// mstore(0xc0, _3)
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// mstore(0xa0, _2)
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// mstore(0xe0, mload(0x260))
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// mstore(0x100, mload(0x280))
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// mstore(0x140, t2_x)
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// mstore(0x120, t2_x_1)
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// let _6 := 0x180
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// mstore(_6, t2_y)
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// mstore(0x160, t2_y_1)
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// let success := call(gas(), 8, 0, _1, _6, _1, _1)
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// if or(iszero(success), iszero(mload(_1)))
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// {
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// mstore(0, 400)
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// revert(0, _1)
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// }
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// }
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// function validateCommitment(note, k, a)
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// {
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// let gammaX := calldataload(add(note, 0x40))
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// let gammaY := calldataload(add(note, 0x60))
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// let sigmaX := calldataload(add(note, 0x80))
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// let sigmaY := calldataload(add(note, 0xa0))
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// let _1 := 0x30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47
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// let _2 := 0x30644e72e131a029b85045b68181585d2833e84879b9709143e1f593f0000001
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// if iszero(and(and(and(eq(mod(a, _2), a), gt(a, 1)), and(eq(mod(k, _2), k), gt(k, 1))), and(eq(addmod(mulmod(mulmod(sigmaX, sigmaX, _1), sigmaX, _1), 3, _1), mulmod(sigmaY, sigmaY, _1)), eq(addmod(mulmod(mulmod(gammaX, gammaX, _1), gammaX, _1), 3, _1), mulmod(gammaY, gammaY, _1)))))
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// {
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// mstore(0x00, 400)
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// revert(0x00, 0x20)
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// }
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// }
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// function hashCommitments(notes, n)
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// {
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// let i := 0
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// for { } lt(i, n) { i := add(i, 0x01) }
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// {
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// calldatacopy(add(0x300, shl(7, i)), add(add(notes, mul(i, 0xc0)), 0x60), 0x80)
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// }
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// mstore(0, keccak256(0x300, shl(7, n)))
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// }
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// }
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