signer - Documentation

Module to ECDSA signatures over structured data, following the EIP712 standard

Source:

src/signer/index.js, line 1

Methods

(inner) generateACEDomainParams(verifyingContract) → {Object}

Generate EIP712 domain parameters for ACE.sol

Parameters:

Name	Type	Description
`verifyingContract`	string	address of target contract

Source:

src/signer/index.js, line 17

(inner) generateDAIDomainParams()

Generate EIP712 domain parameters for DAI token

Parameters:

Type	Description

Source:

src/signer/index.js, line 57

(inner) generateZKAssetDomainParams(verifyingContract) → {Object}

Generate EIP712 domain parameters for ZkAsset.sol

Parameters:

Name	Type	Description
`verifyingContract`	string	address of target contract

Source:

src/signer/index.js, line 44

(inner) signApprovalForProof(verifyingContract, proofOutputs, spender, approval, privateKey) → {string}

Create an EIP712 ECDSA signature over an AZTEC proof, used to either grant or revoke delegation of proof execution to a third party using the approveProof() method of a ZkAsset.

ECSA signature is formatted as follows:

r and s occupy 32 bytes
v occupies 1 byte

Parameters:

Name	Type	Description
`verifyingContract`	string	address of target contract
`proofOutputs`	string	outputs of a proof
`spender`	string	address to which note control is being delegated
`approval`	bool	boolean (true for approval, false for revocation)
`privateKey`	string	the private key of message signer

Source:

src/signer/index.js, line 125

(inner) signNoteACEDomain(verifyingContract, spender, privateKey) → {Array.<string>}

Create an EIP712 ECDSA signature over an AZTEC note, for an ACE.sol domain.

Formats r and s as occupying 32 bytes, and v as occupying 1 byte

Parameters:

Name	Type	Description
`verifyingContract`	string	address of target contract
`spender`	string	address of the note spender
`privateKey`	string	the private key of message signer

Source:

src/signer/index.js, line 223

(inner) signNoteForConfidentialApprove(verifyingContract, noteHash, spender, spenderApproval, privateKey) → {string}

Create an EIP712 ECDSA signature over an AZTEC note, suited for the confidentialApprove() method of a ZkAsset. The ZkAsset.confidentialApprove() method must be called when granting note spending permission to a third party and is required in order for ZkAsset.confidentialTransferFrom() to be successful.

This is expected to be the most commonly used note signing() function. However for use cases, such as testing, where ACE domain params are required then the signNoteACEDomain() function is available.

Formats r and s as occupying 32 bytes, and v as occupying 1 byte

Parameters:

Name	Type	Description
`verifyingContract`	string	address of target contract
`noteHash`	string	noteHash of the note being signed
`spender`	string	address of the note spender
`spenderApproval`	bool	boolean determining whether the spender is being granted approval or revoked
`privateKey`	string	the private key of message signer

Source:

src/signer/index.js, line 83

(inner) signNoteForConfidentialTransfer(verifyingContract, noteOwnerAccount, noteHash, challenge, sender) → {string}

Create an EIP712 ECDSA signature over an AZTEC note, to be used to give permission for note expenditure during a zkAsset confidentialTransfer() method call.

Uses the default format of r, s and v as occupying 32 bytes

Parameters:

Name	Type	Description
`verifyingContract`	string	address of target contract
`noteOwnerAccount`	string	Ethereum account (privateKey, publicKey and address) of owner of the note being signed
`noteHash`	string	hash of the note being signed
`challenge`	string	hexadecimal representation of the challenge variable
`sender`	string	address of the transaction sender

Source:

src/signer/index.js, line 192

(inner) signNotesForConfidentialTransfer(verifyingContract, noteOwnerAccounts, notes, challenge, spender) → {string}

Construct EIP712 ECDSA signatures over an array of notes for use in calling confidentialTransfer()

Parameters:

Name	Type	Description
`verifyingContract`	string	address of target contract
`noteOwnerAccounts`	Array.<Object>	Ethereum accounts of the owners of the notes over which signatures are being created. Included in each account is: address, publicKey, privateKey
`notes`	Array.<Object>	array of notes over which signatures are being constructed
`challenge`	string	cryptographic challenge, unique identifier for a proof
`spender`	string	address of the note spender

Source:

src/signer/index.js, line 165

(inner) signPermit(holderAccount, spender, nonce, expiry, allowed)

Allows a user to create a signature for use in the DAI.permit() function. Creates an EIP712 ECDSA signature

Parameters:

Name	Type	Description
`holderAccount`	Object	address that owns the tokens, which is approving a spender to spend
`spender`	Address	address being approved to spend the tokens
`nonce`	Number	nonce of the transaction. Used for replay protection in the DAI token contract
`expiry`	Number	unix timestamp corresponding to the upper boundary for when the permit is valid
`allowed`	Bool	whether approval is being granted or revoked

Source:

src/signer/index.js, line 250

(inner) signTypedData(schema, domain, message, privateKey) → {Array.<string>}

Create an EIP712 ECDSA signature over structured data. This is a low level function that returns the signature parameters in an unstructured form - r, s and v are all 32 bytes in size.

Higher level functions such as signNoteForConfidentialApprove() and signNotesForConfidentialTransfer() will then format the signature params as required by the relevant verification procedure.

Parameters:

Name	Type	Description
`schema`	string	JSON object that defines the structured data of the signature
`domain`	Array.<string>	variables required for the domain hash part of the signature
`message`	string	the Ethereum address sending the AZTEC transaction (not necessarily the note signer)
`privateKey`	string	the private key of message signer

Source:

src/signer/index.js, line 278