script: start using scriptnum implementation.

docs/Scripting.md

@@ -3,13 +3,13 @@ Scripts are array-like objects with some helper functions.
 ``` js
 var bcoin = require('bcoin');
 var assert = require('assert');
-var BN = bcoin.bn;
+var ScriptNum = bcoin.scriptnum;
 var opcodes = bcoin.script.opcodes;
 
 var output = new bcoin.script();
 output.push(opcodes.OP_DROP);
 output.push(opcodes.OP_ADD);
-output.push(new BN(7));
+output.push(new ScriptNum(7));
 output.push(opcodes.OP_NUMEQUAL);
 // Compile the script to its binary representation
 // (you must do this if you change something!).
@@ -18,8 +18,8 @@ assert(output.getSmall(2) === 7); // compiled as OP_7
 
 var input = new bcoin.script();
 input.set(0, 'hello world'); // add some metadata
-input.push(new BN(2));
-input.push(new BN(5));
+input.push(new ScriptNum(2));
+input.push(new ScriptNum(5));
 input.push(input.shift());
 assert(input.getString(2) === 'hello world');
 input.compile();
@@ -40,10 +40,10 @@ Stack object (an array-like object containing Buffers).
 
 ``` js
 var witness = new bcoin.witness();
-witness.push(new BN(2));
-witness.push(new BN(5));
+witness.push(new ScriptNum(2));
+witness.push(new ScriptNum(5));
 witness.push('hello world');
 
 var stack = witness.toStack();
 output.execute(stack);
-```
+```

lib/bcoin-browser.js

@@ -240,6 +240,7 @@ bcoin.txscript = require('./script');
 bcoin.opcode = require('./script/opcode');
 bcoin.program = require('./script/program');
 bcoin.script = require('./script/script');
+bcoin.scriptnum = require('./script/scriptnum');
 bcoin.sigcache = require('./script/sigcache');
 bcoin.stack = require('./script/stack');
 bcoin.witness = require('./script/witness');

lib/bcoin.js

@@ -277,6 +277,7 @@ bcoin.define('txscript', './script');
 bcoin.define('opcode', './script/opcode');
 bcoin.define('program', './script/program');
 bcoin.define('script', './script/script');
+bcoin.define('scriptnum', './script/scriptnum');
 bcoin.define('sigcache', './script/sigcache');
 bcoin.define('stack', './script/stack');
 bcoin.define('witness', './script/witness');

lib/mining/template.js

@@ -11,7 +11,6 @@ const assert = require('assert');
 const util = require('../utils/util');
 const digest = require('../crypto/digest');
 const merkle = require('../crypto/merkle');
-const BN = require('../crypto/bn');
 const StaticWriter = require('../utils/staticwriter');
 const Address = require('../primitives/address');
 const TX = require('../primitives/tx');
@@ -23,6 +22,7 @@ const policy = require('../protocol/policy');
 const encoding = require('../utils/encoding');
 const CoinView = require('../coins/coinview');
 const Script = require('../script/script');
+const ScriptNum = require('../script/scriptnum');
 const common = require('./common');
 const DUMMY = Buffer.alloc(0);
 
@@ -241,7 +241,8 @@ BlockTemplate.prototype.createCoinbase = function createCoinbase(hash) {
   const input = new Input();
 
   // Height (required in v2+ blocks)
-  input.script.push(new BN(this.height));
+  const height = ScriptNum.fromNumber(this.height);
+  input.script.push(height);
 
   // Coinbase flags.
   input.script.push(encoding.ZERO_HASH160);

lib/script/common.js

@@ -12,7 +12,6 @@
  */
 
 const assert = require('assert');
-const BN = require('../crypto/bn');
 const util = require('../utils/util');
 const secp256k1 = require('../crypto/secp256k1');
 
@@ -532,6 +531,28 @@ exports.isSignatureEncoding = function isSignatureEncoding(sig) {
   return true;
 };
 
+/**
+ * Cast a big number or Buffer to a bool.
+ * @see CastToBool
+ * @param {Buffer} value
+ * @returns {Boolean}
+ */
+
+exports.toBool = function toBool(value) {
+  assert(Buffer.isBuffer(value));
+
+  for (let i = 0; i < value.length; i++) {
+    if (value[i] !== 0) {
+      // Cannot be negative zero
+      if (i === value.length - 1 && value[i] === 0x80)
+        return false;
+      return true;
+    }
+  }
+
+  return false;
+};
+
 /**
  * Format script code into a human readable-string.
  * @param {Array} code
@@ -692,109 +713,6 @@ exports.formatStackASM = function formatStackASM(items, decode) {
   return out.join(' ');
 };
 
-/**
- * Create a CScriptNum.
- * @param {Buffer} value
- * @param {Boolean?} minimal
- * @param {Number?} size - Max size in bytes.
- * @returns {BN}
- * @throws {ScriptError}
- */
-
-exports.num = function num(value, minimal, size) {
-  assert(Buffer.isBuffer(value));
-
-  if (size == null)
-    size = 4;
-
-  if (value.length > size)
-    throw new exports.ScriptError('UNKNOWN_ERROR', 'Script number overflow.');
-
-  if (minimal && value.length > 0) {
-    // If the low bits on the last byte are unset,
-    // fail if the value's second to last byte does
-    // not have the high bit set. A number can't
-    // justify having the last byte's low bits unset
-    // unless they ran out of space for the sign bit
-    // in the second to last bit. We also fail on [0]
-    // to avoid negative zero (also avoids positive
-    // zero).
-    if (!(value[value.length - 1] & 0x7f)) {
-      if (value.length === 1 || !(value[value.length - 2] & 0x80)) {
-        throw new exports.ScriptError(
-          'UNKNOWN_ERROR',
-          'Non-minimally encoded Script number.');
-      }
-    }
-  }
-
-  if (value.length === 0)
-    return new BN(0);
-
-  const result = new BN(value, 'le');
-
-  // If the input vector's most significant byte is
-  // 0x80, remove it from the result's msb and return
-  // a negative.
-  // Equivalent to:
-  // -(result & ~(0x80 << (8 * (value.length - 1))))
-  if (value[value.length - 1] & 0x80)
-    result.setn((value.length * 8) - 1, 0).ineg();
-
-  return result;
-};
-
-/**
- * Create a script array. Will convert Numbers and big
- * numbers to a little-endian buffer while taking into
- * account negative zero, minimaldata, etc.
- * @example
- * assert.deepEqual(Script.array(0), Buffer.alloc(0));
- * assert.deepEqual(Script.array(0xffee), Buffer.from('eeff00', 'hex'));
- * assert.deepEqual(Script.array(new BN(0xffee)), Buffer.from('eeff00', 'hex'));
- * assert.deepEqual(Script.array(new BN(0x1e).neg()), Buffer.from('9e', 'hex'));
- * @param {Number|BN} value
- * @returns {Buffer}
- */
-
-exports.array = function array(value) {
-  if (typeof value === 'number') {
-    assert(util.isInt(value));
-    value = new BN(value);
-  }
-
-  assert(BN.isBN(value));
-
-  if (value.cmpn(0) === 0)
-    return exports.STACK_FALSE;
-
-  // If the most significant byte is >= 0x80
-  // and the value is positive, push a new
-  // zero-byte to make the significant
-  // byte < 0x80 again.
-
-  // If the most significant byte is >= 0x80
-  // and the value is negative, push a new
-  // 0x80 byte that will be popped off when
-  // converting to an integral.
-
-  // If the most significant byte is < 0x80
-  // and the value is negative, add 0x80 to
-  // it, since it will be subtracted and
-  // interpreted as a negative when
-  // converting to an integral.
-
-  const neg = value.cmpn(0) < 0;
-  const result = value.toArray('le');
-
-  if (result[result.length - 1] & 0x80)
-    result.push(neg ? 0x80 : 0);
-  else if (neg)
-    result[result.length - 1] |= 0x80;
-
-  return Buffer.from(result);
-};
-
 /**
  * An error thrown from the scripting system,
  * potentially pertaining to Script execution.

lib/script/index.js

@@ -14,7 +14,7 @@ exports.common = require('./common');
 exports.Opcode = require('./opcode');
 exports.Program = require('./program');
 exports.Script = require('./script');
-// exports.ScriptNum = require('./scriptnum');
+exports.ScriptNum = require('./scriptnum');
 exports.sigcache = require('./sigcache');
 exports.Stack = require('./stack');
 exports.Witness = require('./witness');

lib/script/opcode.js

@@ -8,7 +8,7 @@
 'use strict';
 
 const assert = require('assert');
-const BN = require('../crypto/bn');
+const ScriptNum = require('./scriptnum');
 const util = require('../utils/util');
 const common = require('./common');
 const BufferReader = require('../utils/reader');
@@ -334,12 +334,23 @@ Opcode.fromPush = function fromPush(data) {
 
 /**
  * Instantiate an opcode from a Number.
- * @param {Number|BN} num
+ * @param {Number|ScriptNum|BN} num
  * @returns {Opcode}
  */
 
 Opcode.fromNumber = function fromNumber(num) {
-  return Opcode.fromData(common.array(num));
+  return Opcode.fromData(ScriptNum.encode(num));
+};
+
+/**
+ * Instantiate an opcode from a Number.
+ * @param {Boolean} value
+ * @returns {Opcode}
+ */
+
+Opcode.fromBool = function fromBool(value) {
+  assert(typeof value === 'boolean');
+  return Opcode.fromSmall(value ? 1 : 0);
 };
 
 /**
@@ -368,7 +379,7 @@ Opcode.fromString = function fromString(data, enc) {
 
 /**
  * Instantiate a pushdata opcode from anything.
- * @param {String|Buffer|Number|BN|Opcode} data
+ * @param {String|Buffer|Number|ScriptNum|Opcode} data
  * @returns {Opcode}
  */
 
@@ -385,7 +396,10 @@ Opcode.from = function from(data) {
   if (typeof data === 'string')
     return Opcode.fromString(data, 'utf8');
 
-  if (BN.isBN(data))
+  if (typeof data === 'boolean')
+    return Opcode.fromBool(data);
+
+  if (ScriptNum.isEncodable(data))
     return Opcode.fromNumber(data);
 
   throw new Error('Bad data for opcode.');