smacco.js

// SMACCO implementation on javascript, generating C# code
// SMart ACcount COmposer
// MIT License

(function(exports) {
"use strict";

function Smacco(config) {
  if(config.standard == "smacco-1.0")
	  this.config = config;
  else
    console.log("Unsupported standard: "+config.standard);
}

Smacco._construct = function(config) {
	return new Smacco(config);
};

Smacco.prototype.csGenerateAccount = function() {
  var code = this.csGenerateHeaders();
  var rules = [];
  if(this.config.rules)
    rules = this.config.rules;
  else if(this.config.rule)
    rules.push(this.config.rule);
  var pubkey_list = [];
  if(this.config.pubkey_list)
    pubkey_list = this.config.pubkey_list;
  code += Smacco.csGeneratePubKeyList(pubkey_list);
  if(this.config.input_type == "single")
    code += Smacco.csGenerateSingleAccount(rules, pubkey_list, (!this.config.default_rule && !this.config.inline_last));
  if(this.config.input_type == "array")
    code += Smacco.csGenerateArrayAccount(rules, pubkey_list, (!this.config.default_rule && !this.config.inline_last));
  code += this.csGenerateFooter();
	return code;
};

Smacco.prototype.csGenerateHeaders = function() {
  var code = "using Neo.SmartContract.Framework;\n\
using Neo.SmartContract.Framework.Services.Neo;\n\
using Neo.SmartContract.Framework.Services.System;\n\
namespace NeoContract1 {\n\
public class Contract1 : SmartContract {\n\
";
	return code;
};

Smacco.prototype.csGenerateFooter = function() {
  var code = "";
  // "default_rule" ignores "inline_last" parameter... to inline last, must not use default!
  // if inline is disabled, or any default_rule is presented
  if((this.config.inline_last == "disabled") || this.config.default_rule) {
    if(this.config.default_rule == "DENY_ALL")
      code += "return false;\n";
    else if(this.config.default_rule == "ALLOW_ALL")
      code += "return true;\n";
  }
  code += "}\n\
}\n\
}\n\
";
	return code;
};

Smacco.csGeneratePubKeyList = function(pubkey_list) {
  var code = "";
  for(var pk=0; pk<pubkey_list.length; pk++)
    code += "public static readonly byte[] pubkey_"+pk+" = \""+pubkey_list[pk]+"\".HexToBytes();\n";
  return code;
}

Smacco.csGenerateSingleAccount = function(rules, pubkey_list, inline_last=true) {
  var code = "public static bool Main(byte[] signature){\n";
  var has_return = false;
  for(var r=0; r<rules.length; r++) {
    var rule_output = Smacco.csGenerateRule(rules[r], pubkey_list, (inline_last&&(r==rules.length-1)) );
    code = rule_output.methods + code + rule_output.main_code;
  }
	return code;
};

Smacco.csGenerateArrayAccount = function(rules, pubkey_list, inline_last=true) {
  var code = "public static bool Main(byte[][] signatures){\n";
  for(var r=0; r<rules.length; r++) {
    var rule_output = Smacco.csGenerateRule(rules[r], pubkey_list, (inline_last&&(r==rules.length-1)) );
    code = rule_output.methods + code + rule_output.main_code;
  }
	return code;
};

Smacco.csGenerateRule = function(rule, pubkey_list, should_inline=false) {
  var struct_condition = Smacco.csGenerateCondition(rule.condition, pubkey_list);
  if(should_inline) {
    var code = "return ("+struct_condition.condition_code+");\n";
  }
  else {
    var code = "if("+struct_condition.condition_code+")\nreturn ";
    if(rule.rule_type == "DENY_IF")
      code += "false;\n";
    else if(rule.rule_type == "ALLOW_IF")
      code += "true;\n";
  }
	return {main_code: code, methods: struct_condition.methods};
};

Smacco.csGenerateCondition = function(condition, pubkey_list) {
  var lcode = "";
  var lmethods = "";
  if(condition.condition_type == "CHECKMULTISIG") {
    var local_pubkey_list = pubkey_list;
    // if parameter "pubkeys", use it!
    if(condition.pubkeys)
      local_pubkey_list = condition.pubkeys;
    var sigCount = -1;
    if(condition.minimum_required)
      sigCount = condition.minimum_required;
    if((sigCount == -1) && (condition.signatures))
      sigCount = condition.signatures.length;
    var condName = "";
    if(condition.condition_name)
       condName = condition.condition_name;
    if(condName == "") // standard function name
      condName="CheckMultiSig"+sigCount+"_"+local_pubkey_list.length;

    lcode = condName+"(signatures)";
    lmethods = "public static bool "+condName+"(byte[][] signatures){\n\
byte[][] vpub = new[] {";

    for(var pb=0; pb<local_pubkey_list.length;pb++) {
      lmethods += "pubkey_"+pb;
      if(pb != local_pubkey_list.length-1)
        lmethods+=", ";
    }
    lmethods += "};\n\
byte[][] vsig = new[] {";
    if(condition.signatures)
      for(var sig=0; sig<condition.signatures.length;sig++) {
        lmethods += "signatures["+sig+"]";
        if(sig != condition.signatures.length-1)
          lmethods+=", ";
      }
    else if(condition.minimum_required)
      for(var sig=0; sig<condition.minimum_required;sig++) {
        lmethods += "signatures["+sig+"]";
        if(sig != condition.minimum_required-1)
          lmethods+=", ";
      }
    lmethods += "};\n\
return VerifySignatures(vsig, vpub);\n";
    lmethods += "}\n";
  }
  else if(condition.condition_type == "CHECKSIG") {
    var pbkey = "0"; // default is pubkey_0
    if(condition.pubkey)
      pbkey = condition.pubkey;
    lcode = "VerifySignature(signature, pubkey_"+pbkey+")";
    lmethods = "";
  }
  else if(condition.condition_type == "TIMESTAMP_LESS") {
    var timestamp = 0;
    if(condition.timestamp)
      timestamp = parseInt(String(condition.timestamp));
    if(condition.utc)
      timestamp = Math.round(new Date(condition.utc).valueOf()/1000);
    lcode = "Blockchain.GetHeader(Blockchain.GetHeight()).Timestamp < "+timestamp;
    lmethods = "";
  }
  else if(condition.condition_type == "TIMESTAMP_GREATER") {
    var timestamp = 0;
    if(condition.timestamp)
      timestamp = parseInt(String(condition.timestamp));
    if(condition.utc)
      timestamp = Math.round(new Date(condition.utc).valueOf()/1000);
    lcode = "Blockchain.GetHeader(Blockchain.GetHeight()).Timestamp > "+timestamp;
    lmethods = "";
  }
  else if(condition.condition_type == "SELF_TRANSFER") {
    var condName = "SelfTransfer";
    if(condition.condition_name)
       condName = condition.condition_name;
    lcode = condName+"()";
    lmethods = "public static bool "+condName+"(){\n\
Transaction tx = (Transaction)ExecutionEngine.ScriptContainer;\n\
TransactionOutput[] outputs = tx.GetOutputs();\n\
foreach (TransactionOutput output in outputs)\n\
if (output.ScriptHash != ExecutionEngine.ExecutingScriptHash)\n\
return false;\n\
return true;\n";
    lmethods += "}\n";
  }
  else if(condition.condition_type == "ONLY_NEO") {
    var condName = "OnlyNeo";
    if(condition.condition_name)
       condName = condition.condition_name;
    lcode = condName+"()";
    lmethods = "private static readonly byte[] NeoAssetId = { 155, 124, 255, 218, 166, 116, 190, 174, 15, 147, 14, 190, 96, 133, 175, 144, 147, 229, 254, 86, 179, 74, 92, 34, 12, 205, 207, 110, 252, 51, 111, 197 };\n";
    lmethods += "public static bool "+condName+"(){\n\
Transaction tx = (Transaction)ExecutionEngine.ScriptContainer;\n\
TransactionOutput[] outputs = tx.GetOutputs();\n\
foreach (TransactionOutput output in outputs)\n\
if (output.AssetId != NeoAssetId)\n\
return false;\n\
return true;\n";
    lmethods += "}\n";
  }
  else if(condition.condition_type == "ONLY_GAS") {
    var condName = "OnlyGas";
    if(condition.condition_name)
       condName = condition.condition_name;
    lcode = condName+"()";
    lmethods = "private static readonly byte[] GasAssetId = { 231, 45, 40, 105, 121, 238, 108, 177, 183, 230, 93, 253, 223, 178, 227, 132, 16, 11, 141, 20, 142, 119, 88, 222, 66, 228, 22, 139, 113, 121, 44, 96 };\n";
    lmethods += "public static bool "+condName+"(){\n\
Transaction tx = (Transaction)ExecutionEngine.ScriptContainer;\n\
TransactionOutput[] outputs = tx.GetOutputs();\n\
foreach (TransactionOutput output in outputs)\n\
if (output.AssetId != GasAssetId)\n\
return false;\n\
return true;\n";
    lmethods += "}\n";
  }
  else if(condition.condition_type == "AND") {
    var lcode = "";
    var lmethods = "";
    for(var i=0; i<condition.conditions.length; i++) {
      var code_pair = Smacco.csGenerateCondition(condition.conditions[i], pubkey_list);
      lcode += "("+code_pair.condition_code+")";
      if(i < condition.conditions.length-1)
        lcode += " && "
      lmethods += code_pair.methods;
    }
  }
  else if(condition.condition_type == "OR") {
    var lcode = "";
    var lmethods = "";
    for(var i=0; i<condition.conditions.length; i++) {
      var code_pair = Smacco.csGenerateCondition(condition.conditions[i], pubkey_list);
      lcode += "("+code_pair.condition_code+")";
      if(i < condition.conditions.length-1)
        lcode += " || "
      lmethods += code_pair.methods;
    }
  }
  else {
    lcode = "true";
    lmethods = "";
  }

	return {condition_code: lcode, methods: lmethods};
};

// =========================== FLOWCHART.JS CODE =======================

Smacco.prototype.generateFlowChart = function() {
  var fcCode = "";
  if(this.config.input_type == "single")
    fcCode += "input=>start: Single Signature Input|past\n";
  if(this.config.input_type == "array")
    fcCode += "input=>start: Array Signature Input|past\n";
  fcCode += "accept=>end: Accept (ALLOW)|approved\n";
  fcCode += "deny=>end: Reject (DENY)|rejected\n";

  var fcRulesCode = "";

  var rules = [];
  if(this.config.rules)
    rules = this.config.rules;
  else if(this.config.rule)
    rules.push(this.config.rule);

  if(rules.length > 0)
    fcRulesCode += "input->Rule0\n";
  else {
    if(this.config.default_rule=="ALLOW_ALL")
      fcRulesCode += "input->accept\n";
    else
      fcRulesCode += "input->deny\n";
  }

  var pubkey_list = [];
  if(this.config.pubkey_list)
    pubkey_list = this.config.pubkey_list;
  var inline_last = (!this.config.default_rule && !this.config.inline_last);

  for(var r=0; r<rules.length; r++) {
    var rule_output = Smacco.fcGenerateRule(rules[r], r, pubkey_list, (inline_last&&(r==rules.length-1)) );
    fcCode += rule_output.declarations;
    fcRulesCode += rule_output.arrows;
  }

/*
Rule0=>condition: Before 2018-09-20 11:00:00Z
Rule1=>condition: CheckSig(03624...568fb)
input->Rule0
Rule0(yes)->deny
Rule0(no)->Rule1
Rule1(yes)->accept
Rule1(no)->deny
*/
  return fcCode+fcRulesCode;
}


Smacco.fcGenerateRule = function(rule, rule_id, pubkey_list, should_inline=false) {
  var declarations = "Rule"+rule_id+"=>condition: ";
  var fcCodeCondition = Smacco.fcGenerateCondition(rule.condition, pubkey_list);
  declarations += fcCodeCondition+"\n";

  var arrows = "";

  if(should_inline) {
    if(rule.rule_type == "DENY_IF") {
      arrows += "Rule"+rule_id+"(yes)->deny\n";
      arrows += "Rule"+rule_id+"(no)->accept\n";
    }
    if(rule.rule_type == "ALLOW_IF") {
      arrows += "Rule"+rule_id+"(yes)->accept\n";
      arrows += "Rule"+rule_id+"(no)->deny\n";
    }
  } else {
    if(rule.rule_type == "DENY_IF") {
      arrows += "Rule"+rule_id+"(yes)->deny\n";
      arrows += "Rule"+rule_id+"(no)->Rule"+(rule_id+1)+"\n";
    }
    if(rule.rule_type == "ALLOW_IF") {
      arrows += "Rule"+rule_id+"(yes)->accept\n";
      arrows += "Rule"+rule_id+"(no)->Rule"+(rule_id+1)+"\n";
    }
  }

	return {declarations: declarations, arrows: arrows};
};

Smacco.ellipsePubkey = function(pubkey) {
  return pubkey.substr(0,5)+"..."+pubkey.slice(pubkey.length-5);
}

Smacco.fcGenerateCondition = function(condition, pubkey_list) {
  var lcode = "";
  if(condition.condition_type == "CHECKMULTISIG") {
    var local_pubkey_list = pubkey_list;
    // if parameter "pubkeys", use it!
    if(condition.pubkeys)
      local_pubkey_list = condition.pubkeys;
    var sigCount = -1;
    if(condition.minimum_required)
      sigCount = condition.minimum_required;
    if((sigCount == -1) && (condition.signatures))
      sigCount = condition.signatures.length;
    var condName = "";
    if(condition.condition_name)
       condName = condition.condition_name;

    lcode = "CheckMultiSig("+sigCount;
    lcode += " / " + local_pubkey_list.length + ")";
/*
    lcode+="; {";
    for(var pb=0; pb<local_pubkey_list.length;pb++) {
      lcode += Smacco.ellipsePubkey(local_pubkey_list[pb]);
      if(pb != local_pubkey_list.length-1)
        lcode+=", ";
    }
    lcode += "})";
*/
  }
  else if(condition.condition_type == "CHECKSIG") {
    var pbkey = "0"; // default is pubkey_0
    if(condition.pubkey)
      pbkey = condition.pubkey;
    if(pbkey.length<=2)
      pbkey = pubkey_list[new Number(pbkey)];
    lcode = "CheckSig("+Smacco.ellipsePubkey(pbkey)+")";
  }
  else if(condition.condition_type == "TIMESTAMP_LESS") {
    var timestamp = 0;
    if(condition.timestamp)
      timestamp = parseInt(String(condition.timestamp));
    if(condition.utc)
      timestamp = Math.round(new Date(condition.utc).valueOf()/1000);
    var dt = new Date(timestamp*1000);
    var isoText = dt.toISOString().split("T")[0] + " " + dt.toISOString().split("T")[1].split("Z")[0].substr(0,8)+"Z";
    lcode = "Before "+isoText;
  }
  else if(condition.condition_type == "TIMESTAMP_GREATER") {
    var timestamp = 0;
    if(condition.timestamp)
      timestamp = parseInt(String(condition.timestamp));
    if(condition.utc)
      timestamp = Math.round(new Date(condition.utc).valueOf()/1000);
    var dt = new Date(timestamp*1000);
    var isoText = dt.toISOString().split("T")[0] + " " + dt.toISOString().split("T")[1].split("Z")[0].substr(0,8)+"Z";
    lcode = "After "+isoText;
  }
  else if(condition.condition_type == "SELF_TRANSFER") {
    lcode = "SelfTransfer";
  }
  else if(condition.condition_type == "ONLY_NEO") {
    lcode = "OnlyNeo";
  }
  else if(condition.condition_type == "ONLY_GAS") {
    lcode = "OnlyGas";
  }
  else if(condition.condition_type == "AND") {
    for(var i=0; i<condition.conditions.length; i++) {
      var code_out = Smacco.fcGenerateCondition(condition.conditions[i], pubkey_list);
      lcode += "("+code_out+")";
      if(i < condition.conditions.length-1)
        lcode += " && "
    }
  }
  else if(condition.condition_type == "OR") {
    for(var i=0; i<condition.conditions.length; i++) {
      var code_out = Smacco.fcGenerateCondition(condition.conditions[i], pubkey_list);
      lcode += "("+code_out+")";
      if(i < condition.conditions.length-1)
        lcode += " || "
    }
  }
  else {
    lcode = "true";
  }

	return lcode;
};

exports.Smacco = Smacco;
})(typeof exports !== 'undefined' ? exports : this);