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In Hyperledger-Fabric how to get Ethereum like "msg.sender" in chaincode? (also when chaincode A calls chaincode B, will the "msg.sender" be script-address of A (like in Ethereum)?

Rupert Redding
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2 Answers2

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To add onto Mo-Che Chan's answer:

func (stub *ChaincodeStub) GetCreator() ([]byte, error)

GetCreator returns SignatureHeader.Creator of the signedProposal this Stub refers to.

GetCreator should get signedProposal and proposal.

From the HyperLedger blog:

The Creator field holds x.509 certificate, public key and membership service provided (MSP) who issued these identity to the client. The Nonce field contains some random bytes.

type SignatureHeader struct {   
    Creator []byte 
    Nonce []byte 
}

And from another post on the same blog, a diagram of the block structure. It has a section in each transaction (see row 4) for

Creator Identity (certificate, public key) - Client

It seems as if yes, this would be the equivalent of msg.sender in Solidity.

Block structure

k26dr
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  • Thank you for referencing the blog, I don't know how I haven't found it sooner. Is there a preferred/easy way to reconstruct the Creator Identity part design time (since I need to embed the content, i.e. the byte array, into the chaincode)? Should I concatenate some crypto materials (if so, which ones), or should I hijack an SDK request sent toward the network and extract it from that? – Attila Klenik Oct 12 '17 at 11:14
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func (stub *ChaincodeStub) GetCreator() ([]byte, error)

GetCreator returns SignatureHeader.Creator of the signedProposal this Stub refers to.

GetCreator should get signedProposal and proposal.

Mo-Che Chan
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    I'm more concerned about second part of my question. Paraphrasing - can chaincode act as account? (when chaincode A calls chaincode B, will the "msg.sender" be script-address of A?) – Rupert Redding May 16 '17 at 04:26