README.MD

supply-chain-services

configuration

To run locally, copy the file dev.sample.json in the config folder and create a new file called dev.private.json.

Fill in the following values:

CONTRACT_ADDRESS: Your contract address, see details below ACCOUNT_ADDRESS : Your account address, see details below GAS: The default GAS value GET_RPC_ENDPOINT : The RPC endpoint AZURE_STORAGE_CONNECTION_STRING- A connection string to your Azure Storage Account where we keep the keys to encrypt and decrypt the proofs

When deploying to production, fill these values in the environment variables.

update smart contracts

Open the supply-chain-smart-contracts project and update your contract run truffle deploy open the built contract in the build folder and copy the abi portion into the clipboard copy it into http://www.textfixer.com/tools/remove-line-breaks.php to remove the line breaks then set the new string as the value for your abi:

const proofAbi = [ { "constant": ... }];

run truffle migrate --reset to deploy and migrate the contract copy the address of the deployed contract and set this as an environment variable CONTRACT_ADDRESS either in your local config.json or as an AppSetting in the WebApp environment:

"CONTRACT_ADDRESS" : "0xa6608368fdc4d4db4e802583c16f6f0baa338ef9";

you then can create an instance of the contract by using the abi and the address:

const contractAddress = nconf.get('CONTRACT_ADDRESS');
var contractInstance = web3.eth.contract(proofAbi).at(contractAddress);

Specify the Ethereum address

In addition to deploying the contract, you also need to create an Ethereum account and link this to the service through the environment setting called ACCOUNT_ADDRESS such as here in the local config.json:

   "ACCOUNT_ADDRESS" : "0x79178125ba23619951847a7149c6e0e0f1804baf"

Proof API calls

PUT

PUT creates a measurement for new produce - basically the starting point of the chain. trackingId becomes the resource identifier and only one PUT per trackingId is a allowed. Or in other words, the initial PUT is immutable.

The following request adds a new proof to the chain:

{
  "trackingId" : "trackingId_1",
  "userId" : "producer_01",
  "proofToEncrypt": {
    "proof": "This content will be encrypted before storing"
  },
  "publicProof" : {
    "producerId": "farmer1",
    "email": "test@farmer1.de"
  }
}

The trackingId is optional. If it wasn't provided by the caller, a new GUID will be generated and will be returned as part of the response:

{
  "trackingId" : "<the tracking Id>",
  "txHash": "<the transaction hash in the blockchain>"
}

In order to create a proof that is chained to a previous already-existing proof, add the previousTrackingId field. Note: This will only work if the previousTrackingId proof is owned by the calling account, or if it has been transfered to the executing account using the PATCH method as demonstrated below.

The following request adds a new proof that is chained to the previous one:

{
  "trackingId" : "trackingId_2",
  "userId" : "producer_02",
  "previousTrackingId": "trackingId_1",
  "proofToEncrypt": {
    "proof": "This content will be encrypted before storing"
  },
  "publicProof" : {
    "producerId": "farmer1",
    "email": "test@farmer1.de"
  }
}

PATCH

PATCH transfers the ownership to a new account to allow adding additional proofs to the produce. After a succesful PATCH, the owner of the trasnferTo account can use the specified trackingId as it's previousTrackingId in a subsequent PUT.

{
  "trackingId" : "trackingId_1",
  "transferTo" : "0x9c45e05370b509c416c4e4981c13c6b023b574c0"
}

GET

GET retrieves a proof and all it's previous proofs and returns it as an array. The trackingId should be provided as part of the URL parameters. After performing the above PUT a GET on /api/proof/trackingId_1?userId=producer_01&decrypt=0 returns the following json:

[
  {
    "trackingId": "trackingId_1",
    "owner": "0x422d337a0375a5108c48706901587a80c8dbef7c",
    "encryptedProof": "RolsKpMso+ZnOHq4YeaQ3chH1aWfng8GPMsw/HdhE5PLyrb4RtgHONWuLqO+ZSBz0cUm5bTzUXLvlrWk4Um7XyBvKccDv9/dEAP3pIO+G9w70qtxKbpeZpdEnR2kAbatuOD5rrFUI4fNJj7NoUncY59o7ppMX3xfDp7U7n9GzAo4Z0667EKw3YNM4gParDKYpuhXcupjN7Xr77SAMpkRF29lxrS23EhXpQ368aUzgdZP5A0YBidI1Ah48sjdroXh",
    "publicProof": {
      "encryptedProofHash": "7898fdd63d28c88d461e3d8f6fd3cad5b1140379d3aa6bf0ba2a4664376468db",
      "publicProof": {
        "producerId": "farmer1",
        "email": "test@farmer1.de"
      }
    },
    "previousTrackingId": "root"
  }
]

A GET on /api/proof/trackingId_1?userId=producer_01&decrypt=1 returns the encryptedProof decrypted. Note: Decryption will only take place if the caller has access to the private key.

[
  {
    "trackingId": "trackingId_1",
    "owner": "0x422d337a0375a5108c48706901587a80c8dbef7c",
    "proofToEncrypt": {
      "value": "This content will be encrypted before storing"
    },
    "publicProof": {
      "encryptedProofHash": "ef4089c73b92e128ac68ebc2e26f6893eec5f1ab4607de2752c73e2a143a1375",
      "publicProof": {
        "producerId": "farmer1",
        "email": "test@farmer1.de"
      }
    },
    "previousTrackingId": "root"
  }
]

If we now perform the above PATCH and PUT operations, a GET on /api/proof/trackingId_2 will return the following json:

[
  {
    "trackingId": "trackingId_2",
    "owner": "0x422d337a0375a5108c48706901587a80c8dbef7c",
    "encryptedProof": "Ymoi1sWmG1GRx9CI9QVsh3PKCgqOesH91OADTYydxRkwU2ee9me3wMykVxX2n2AI//uMUqyMmnm1CMbzjS598gk5pZCskhlJ4tMY/ZGXxm7gBZ/3snoNHKuaAxFASMgAdrjH+/WBnaQYsH55wgKc03e+uhBj6yTeXa06aCNFLKQ=",
    "publicProof": {
      "encryptedProofHash": "7898fdd63d28c88d461e3d8f6fd3cad5b1140379d3aa6bf0ba2a4664376468db",
      "publicProof": {
        "producerId": "farmer2",
        "email": "test@farmer2.de"
      }
    },
    "previousTrackingId": "trackingId_1"
  },
  {
    "trackingId": "trackingId_1",
    "owner": "0x422d337a0375a5108c48706901587a80c8dbef7c",
    "encryptedProof": "Ymoi1sWmG1GRx9CI9QVsh3PKCgqOesH91OADTYydxRkwU2ee9me3wMykVxX2n2AI//uMUqyMmnm1CMbzjS598gk5pZCskhlJ4tMY/ZGXxm7gBZ/3snoNHKuaAxFASMgAdrjH+/WBnaQYsH55wgKc03e+uhBj6yTeXa06aCNFLKQ=",
    "publicProof": {
      "encryptedProofHash": "7898fdd63d28c88d461e3d8f6fd3cad5b1140379d3aa6bf0ba2a4664376468db",
      "publicProof": {
        "producerId": "farmer1",
        "email": "test@farmer1.de"
      }
    },
    "previousTrackingId": "root"
  }
]

Key API calls

IMPORTANT: This api needs only to accept calls from autheticated users. The user Id will be used as the PartitionKey in the key storage.

PUT

PUT creates a new key with the provided keyId and returns the HTTP status code 409 if a key with keyId already exists.

{
  "keyId" : "trackingId_1",
  "userId" : "producer_01"
}

GET

The keyId provided as part of the URL parameters. The api only returns the public but never the private key. A call to /api/key?keyId=trackingId_1&userId=producer_01 returns

{
  "keyId": "trackingId_1",
  "publicKey": "-----BEGIN RSA PUBLIC KEY-----\nMEgCQQDaeW3dIGRrE1ZBwWyFNJc7iZPvSTNXHN5LIbHCAOCwp/W+Fy7PLaKyS4JT\nVhjV1/AmRmwnbeUI9/HZEVGaF573AgMBAAE=\n-----END RSA PUBLIC KEY-----"
}