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Platform Interface Functions

Last Updated: Jan 09, 2020

The Ant Blockchain contract platform allows contract developers to obtain both block and transaction data, and enables them to implement encryption methods.

Block data interface functions

  • block.blockhash(uint blockNumber) returns (bytes32): imports blockNumber and returns the hash value of a block.
  • block.gaslimit (uint): specifies the gas limit of the system.
  • block.number (uint): specifies the block height.
  • block.timestamp (uint): specifies the timestamp when a block is created.
  • now (uint): specifies the alias of block.timestamp.

Transaction data interface functions

In the following methods, information in parentheses () indicates the data types of the returned data.

  • msg.data (bytes): specifies data provided by a user.
  • msg.gas (uint): specifies the gas value of a transaction.
  • msg.sender (identity): specifies the sender of a transaction.
  • msg.sig (bytes4): specifies the first four bytes of the data that a user provides in a transaction.
  • msg.value (uint): specifies the gas value transferred in a transaction.

You can also query the Ant Blockchain contract platform for the hash value of a transaction by using the following method:

  1. tx.txhash (identity)

This method indicates that the data type is identity.

Encryption interface functions

sha256

  • Function prototype
  1. sha256(bytes data) returns(bytes32 result) ;
  • Request parameters
Parameter Required Type Description
data Yes bytes The data to be encrypted.
  • Response parameters
Parameter Required Type Description
result Yes bytes The encryption result of sha256.
Note: The sha256 function is modified for the Ant Blockchain contract platform. This is implemented by using the OpenSSL encryption library.

ecrecover

  • Function prototype
  1. ecrecover(bytes32 hash, uint8 v, bytes32 r,bytes s) returns(identity id) ;
  • Request parameters
Parameter Required Type Description
hash Yes bytes32 The hash result of the signature.
r Yes bytes32 The first 32 bytes of the signature.
s Yes bytes32 The last 32 bytes of the signature.
v Yes uint8 The last byte of the signature.
  • Response parameters
Parameter Required Type Description
id Yes identity The ID of the account.

Note: The ecrecover function is modified for the Ant Blockchain contract platform. After obtaining the public key based on both the signature and the hash value of the signature, the platform uses the sha256 function to encrypt the key and returns the encryption result to the user as an ID.

ripemd160

The Ant Blockchain contract platform does not provide the ripemd160 function library.