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
blockNumberand 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:
tx.txhash (identity / uint256)This method can be used to obtain the hash value of the current transaction. In version 0.4.24, the data type is identity, and in version 0.6.4 and above, the data type is uint256.
Encryption interface functions
sha256
Function prototype
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
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.