// Returns a contract by its block index and validates its signatures
public Dictionary <string, dynamic> GetContract(string index, string privateKey)
{
var user = _usersDataAccess.FindByPublicKey(CryptographyService.GetPublicKeyFromPrivate(privateKey));
var encryptedSecretKey = user.CorrespondingIndices[index];
var block = _blockchainDataAccess.FindByIndex(index);
var composedContract = new Dictionary <string, dynamic>
{
["index"] = block.Index, ["hash"] = block.Hash, ["timestamp"] = block.Timestamp
};
var decryptedSecretKey = CryptographyService.DecryptWithPrivateKey(encryptedSecretKey, privateKey);
var dataToString = JObject.Parse(CryptographyService.Decrypt(block.Data, decryptedSecretKey));
// If decrypted data is a contract indeed
if (!dataToString.ContainsKey("type") || !dataToString["type"].Value <string>().Equals("Contract"))
{
return(null);
}
var contractNoSignatures = JObject.Parse(CryptographyService.Decrypt(block.Data, decryptedSecretKey));
// Delete all signatures, since the signature will be validated on a “clean” contract
((JObject)contractNoSignatures["essentials"]).Property("signatures").Remove();
if (dataToString["essentials"]["type"].Value <string>().Equals("timeCharter"))
{
dataToString["essentials"]["vessel"] =
JToken.FromObject(_vesselsDataAccess.FindByImoNumber(dataToString["essentials"]["vessel"].Value <string>()));
}
foreach (var signature in dataToString["essentials"]["signatures"])
{
foreach (var(key, value) in ((JObject)signature).ToObject <Dictionary <string, dynamic> >())
{
if (key.Equals("signer") || key.Equals("onBehalfOf"))
{
signature[key] = JToken.FromObject(_usersDataAccess.FindByPublicKey(value));
}
}
var signatureToValidate = signature["signature"].Value <string>();
var publicKey = signature["signer"]["publicKey"].Value <string>();
signature["valid"] = CryptographyService.Verify(contractNoSignatures.ToString(Formatting.None), signatureToValidate, publicKey);
}
// Convert each paragraph to readable format and add it to the contract
foreach (var clause in dataToString["clauses"])
{
foreach (var paragraph in clause["paragraphs"])
{
paragraph["readable"] = Clause.GetParagraphReadable(paragraph.ToObject <Dictionary <string, dynamic> >()["legen"]);
}
}
composedContract["contract"] = dataToString;
return(composedContract);
}
