Chaincode Library APIs

The chaincode library is static and integrated in BCS instances. When developing a chaincode, you can use the API file to locally compile the chaincode.

Download the API file (for the download link, see Downloading Resources), and decompress it to the local GOPATH directory. Refer to the example chaincode provided in section 4.2.6 to import the homomorphic encryption library. After the chaincode is developed, install it in the BCS instance. The chaincode will automatically link to the library code in the instance to invoke the homomorphic encryption library for the chaincode.

The code for importing the homomorphic encryption library for the chaincode is import "ahe/PSW/api/ChainCode".

Do not modify this code line. Otherwise, the chaincode fails to invoke the homomorphic encryption library.

ValidateInitBalance

API prototype
func ValidateInitBalance(BalanceInfo, PubKey string) (InitBalance string, err error)
Function description
Verifies the validity of the balance proof in balanceinfo generated by sdk.InitBalance.

Input

Parameter	Type	Description	Mandatory
BalanceInfo	string	Initial balance data	Yes
Pubkey	string	Public key for balance encryption	Yes

Output

Parameter	Type	Description	Mandatory
InitBalance	string	Initial balance ciphertext	Yes
err	error	Error message	Yes

Processing
Balance ciphertext provided after the balance validity verification
Note
The account balance authenticity is ensured by the application logic. The chaincode can only check whether the amount is greater than 0 but cannot determine the actual balance of a user.

ValidateTxInfo

API prototype
ValidateTxInfo(txInfo, cipherBalanceA, cipherBalanceB string) (newCipherBalanceA,newCipherBalanceB,newCipherTxA,newCipherTxB string,err error)
Function description
Verifies the validity of the transaction proof in Txinfo generated by PrepareTxInfo.

Input

Parameter	Type	Description	Mandatory
txinfo	string	Transaction proof data NOTE: The transaction data includes the transaction proof data in addition to the ciphertext of the transaction data. It is obtained from txinfo returned using sdk.PrepareTxInfo.	Yes
cipherBalanceA	string	Current balance of user A (ciphertext)	Yes
cipherBalanceB	string	Current balance of user B (ciphertext)	Yes

Output

Parameter	Type	Description
newCipherBalanceA	string	User A' balance to be updated after the transaction
newCipherBalanceB	string	User B' balance to be updated after the transaction
newCipherTxA	string	Transaction amount (encrypted using user A' homomorphic public-key encryption)
newCipherTxB	string	Transaction amount (encrypted using user B' homomorphic public-key encryption)
err	error	Error message