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https://github.com/tornadocash/tornado-core.git
synced 2024-12-23 18:00:22 +01:00
67 lines
2.3 KiB
Plaintext
67 lines
2.3 KiB
Plaintext
include "../node_modules/circomlib/circuits/bitify.circom";
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include "../node_modules/circomlib/circuits/pedersen.circom";
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include "merkleTree.circom";
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// computes Pedersen(nullifier + secret)
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template CommitmentHasher() {
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signal private input nullifier;
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signal private input secret;
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signal output commitment;
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signal output nullifierHash;
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component commitmentHasher = Pedersen(496);
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component nullifierHasher = Pedersen(248);
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component nullifierBits = Num2Bits(248);
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component secretBits = Num2Bits(248);
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nullifierBits.in <== nullifier;
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secretBits.in <== secret;
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for (var i = 0; i < 248; i++) {
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nullifierHasher.in[i] <== nullifierBits.out[i];
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commitmentHasher.in[i] <== nullifierBits.out[i];
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commitmentHasher.in[i + 248] <== secretBits.out[i];
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}
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commitment <== commitmentHasher.out[0];
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nullifierHash <== nullifierHasher.out[0];
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}
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// Verifies that commitment that corresponds to given secret and nullifier is included in the merkle tree of deposits
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template Withdraw(levels, rounds) {
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signal input root;
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signal input nullifierHash;
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signal input receiver; // not taking part in any computations
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signal input relayer; // not taking part in any computations
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signal input fee; // not taking part in any computations
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signal private input nullifier;
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signal private input secret;
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signal private input pathElements[levels];
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signal private input pathIndex[levels];
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component hasher = CommitmentHasher();
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hasher.nullifier <== nullifier;
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hasher.secret <== secret;
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nullifierHash === hasher.nullifierHash;
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component tree = MerkleTree(levels, rounds);
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tree.leaf <== hasher.commitment;
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tree.root <== root;
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for (var i = 0; i < levels; i++) {
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tree.pathElements[i] <== pathElements[i];
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tree.pathIndex[i] <== pathIndex[i];
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}
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// Add hidden signals to make sure that tampering with receiver or fee will invalidate the snark proof
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// Most likely it is not required, but it's better to stay on the safe side and it only takes 2 constraints
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// Squares are used to prevent optimizer from removing those constraints
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signal receiverSquare;
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signal feeSquare;
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signal relayerSquare;
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receiverSquare <== receiver * receiver;
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feeSquare <== fee * fee;
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relayerSquare <== relayer * relayer;
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}
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component main = Withdraw(16, 220);
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