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Withdraw Offer Signature Structure

To authorize the withdrawOffer operation within the MNS service, the user (the original offeror) must generate a cryptographic signature compliant with the EIP-191 standard.

This signature proves the offeror's intent and authorization to withdraw a specific, previously placed offer from a target username.

Signed Message Format​

The message is constructed by concatenating the following components as strings, separated by commas (,):

string.concat(
   "21811609",
   ",",
   _username,
   ",",
   Strings.toString(_offerId),
   ",",
   Strings.toString(_mateNameServiceNonce)
)

1. MNS Withdraw Offer Identifier (Hex String):

  • Value: 21811609
  • Purpose: A specific identifier used within the EIP-191 framework to distinguish MNS withdrawOffer messages from other types of signed messages.

2. Target Username (String):

  • Value: The _username string itself.
  • Purpose: Specifies the username associated with the offer that is being withdrawn.

3. Offer ID (String):

  • Value: The result of Strings.toString(_offerId).
  • Purpose: The string representation of the unique identifier (uint256) assigned to the specific offer when it was created via makeOffer. This identifies which offer to withdraw.

4. MNS Nonce (String):

  • Value: The result of Strings.toString(_nonce).
  • Purpose: The string representation of the user's (original offeror's) nonce specific to the MNS contract for this withdrawOffer action. This prevents replay attacks.
tip
  • addressToString converts an address to a lowercase string
  • Strings.toString converts a number to a string
  • AdvancedStrings.bytes32ToString(bytes32 _input) converts a bytes32 value into its lowercase hexadecimal string representation