// Invoke is called to validate the specified block of transactions
// This validation system chaincode will check the read-write set validity and at least 1
// correct endorsement. Later we can create more validation system
// chaincodes to provide more sophisticated policy processing such as enabling
// policy specification to be coded as a transaction of the chaincode and the client
// selecting which policy to use for validation using parameter function
// @return serialized Block of valid and invalid transactions indentified
// Note that Peer calls this function with 2 arguments, where args[0] is the
// function name and args[1] is the Envelope
func (vscc *ValidatorOneValidSignature) Invoke(stub shim.ChaincodeStubInterface) ([]byte, error) {
// args[0] - function name (not used now)
// args[1] - serialized Envelope
args := stub.GetArgs()
if len(args) < 2 {
return nil, errors.New("Incorrect number of arguments")
}
if args[1] == nil {
return nil, errors.New("No block to validate")
}
logger.Infof("VSCC invoked")
// get the envelope...
env, err := utils.GetEnvelope(args[1])
if err != nil {
logger.Errorf("VSCC error: GetEnvelope failed, err %s", err)
return nil, err
}
// ...and the payload...
payl, err := utils.GetPayload(env)
if err != nil {
logger.Errorf("VSCC error: GetPayload failed, err %s", err)
return nil, err
}
// validate the payload type
if common.HeaderType(payl.Header.ChainHeader.Type) != common.HeaderType_ENDORSER_TRANSACTION {
logger.Errorf("Only Endorser Transactions are supported, provided type %d", payl.Header.ChainHeader.Type)
return nil, fmt.Errorf("Only Endorser Transactions are supported, provided type %d", payl.Header.ChainHeader.Type)
}
// ...and the transaction...
tx, err := utils.GetTransaction(payl.Data)
if err != nil {
logger.Errorf("VSCC error: GetTransaction failed, err %s", err)
return nil, err
}
// loop through each of the actions within
for _, act := range tx.Actions {
cap, err := utils.GetChaincodeActionPayload(act.Payload)
if err != nil {
logger.Errorf("VSCC error: GetChaincodeActionPayload failed, err %s", err)
return nil, err
}
// this is what is being signed
prespBytes := cap.Action.ProposalResponsePayload
// loop through each of the endorsements
for _, endorsement := range cap.Action.Endorsements {
// extract the identity of the signer
end, err := mspmgmt.GetManagerForChain(payl.Header.ChainHeader.ChainID).DeserializeIdentity(endorsement.Endorser)
if err != nil {
logger.Errorf("VSCC error: DeserializeIdentity failed, err %s", err)
return nil, err
}
// validate it
err = end.Validate()
if err != nil {
return nil, fmt.Errorf("Invalid endorser identity, err %s", err)
}
// verify the signature
err = end.Verify(append(prespBytes, endorsement.Endorser...), endorsement.Signature)
if err != nil {
return nil, fmt.Errorf("Invalid signature, err %s", err)
}
}
}
logger.Infof("VSCC exists successfully")
return nil, nil
}
// validateEndorserTransaction validates the payload of a
// transaction assuming its type is ENDORSER_TRANSACTION
func validateEndorserTransaction(data []byte, hdr *common.Header) ([]*pb.TransactionAction, error) {
putilsLogger.Infof("validateEndorserTransaction starts for data %p, header %s", data, hdr)
// check for nil argument
if data == nil || hdr == nil {
return nil, fmt.Errorf("Nil arguments")
}
// if the type is ENDORSER_TRANSACTION we unmarshal a Transaction message
tx, err := utils.GetTransaction(data)
if err != nil {
return nil, err
}
// check for nil argument
if tx == nil {
return nil, fmt.Errorf("Nil transaction")
}
// TODO: validate tx.Version
// TODO: validate ChaincodeHeaderExtension
if len(tx.Actions) == 0 {
return nil, fmt.Errorf("At least one TransactionAction is required")
}
putilsLogger.Infof("validateEndorserTransaction info: there are %d actions", len(tx.Actions))
for _, act := range tx.Actions {
// check for nil argument
if act == nil {
return nil, fmt.Errorf("Nil action")
}
// if the type is ENDORSER_TRANSACTION we unmarshal a SignatureHeader
sHdr, err := utils.GetSignatureHeader(act.Header)
if err != nil {
return nil, err
}
// validate the SignatureHeader - here we actually only
// care about the nonce since the creator is in the outer header
err = validateSignatureHeader(sHdr)
if err != nil {
return nil, err
}
putilsLogger.Infof("validateEndorserTransaction info: signature header is valid")
// if the type is ENDORSER_TRANSACTION we unmarshal a ChaincodeActionPayload
cap, err := utils.GetChaincodeActionPayload(act.Payload)
if err != nil {
return nil, err
}
// extract the proposal response payload
prp, err := utils.GetProposalResponsePayload(cap.Action.ProposalResponsePayload)
if err != nil {
return nil, err
}
// build the original header by stitching together
// the common ChainHeader and the per-action SignatureHeader
hdrOrig := &common.Header{ChainHeader: hdr.ChainHeader, SignatureHeader: sHdr}
hdrBytes, err := utils.GetBytesHeader(hdrOrig) // FIXME: here we hope that hdrBytes will be the same one that the endorser had
if err != nil {
return nil, err
}
// compute proposalHash
pHash, err := utils.GetProposalHash2(hdrBytes, cap.ChaincodeProposalPayload)
if err != nil {
return nil, err
}
// ensure that the proposal hash matches
if bytes.Compare(pHash, prp.ProposalHash) != 0 {
return nil, fmt.Errorf("proposal hash does not match")
}
}
return tx.Actions, nil
}