pluotsorbet/libs/forge/util.js

/**
 * Utility functions for web applications.
 *
 * @author Dave Longley
 *
 * Copyright (c) 2010-2014 Digital Bazaar, Inc.
 */
(function() {
/* ########## Begin module implementation ########## */
function initModule(forge) {

/* Utilities API */
var util = forge.util = forge.util || {};

// define isArrayBuffer
util.isArrayBuffer = function(x) {
  return typeof ArrayBuffer !== 'undefined' && x instanceof ArrayBuffer;
};

// define isArrayBufferView
var _arrayBufferViews = [];
if(typeof DataView !== 'undefined') {
  _arrayBufferViews.push(DataView);
}
if(typeof Int8Array !== 'undefined') {
  _arrayBufferViews.push(Int8Array);
}
if(typeof Uint8Array !== 'undefined') {
  _arrayBufferViews.push(Uint8Array);
}
if(typeof Uint8ClampedArray !== 'undefined') {
  _arrayBufferViews.push(Uint8ClampedArray);
}
if(typeof Int16Array !== 'undefined') {
  _arrayBufferViews.push(Int16Array);
}
if(typeof Uint16Array !== 'undefined') {
  _arrayBufferViews.push(Uint16Array);
}
if(typeof Int32Array !== 'undefined') {
  _arrayBufferViews.push(Int32Array);
}
if(typeof Uint32Array !== 'undefined') {
  _arrayBufferViews.push(Uint32Array);
}
if(typeof Float32Array !== 'undefined') {
  _arrayBufferViews.push(Float32Array);
}
if(typeof Float64Array !== 'undefined') {
  _arrayBufferViews.push(Float64Array);
}
util.isArrayBufferView = function(x) {
  for(var i = 0; i < _arrayBufferViews.length; ++i) {
    if(x instanceof _arrayBufferViews[i]) {
      return true;
    }
  }
  return false;
};

// TODO: set ByteBuffer to best available backing
util.ByteBuffer = ByteStringBuffer;

/** Buffer w/BinaryString backing */

/**
 * Constructor for a binary string backed byte buffer.
 *
 * @param [b] the bytes to wrap (either encoded as string, one byte per
 *          character, or as an ArrayBuffer or Typed Array).
 */
function ByteStringBuffer(b) {
  // TODO: update to match DataBuffer API

  // the data in this buffer
  this.data = '';
  // the pointer for reading from this buffer
  this.read = 0;

  if(typeof b === 'string') {
    this.data = b;
  } else if(util.isArrayBuffer(b) || util.isArrayBufferView(b)) {
    // convert native buffer to forge buffer
    // FIXME: support native buffers internally instead
    var arr = new Uint8Array(b);
    try {
      this.data = String.fromCharCode.apply(null, arr);
    } catch(e) {
      for(var i = 0; i < arr.length; ++i) {
        this.putByte(arr[i]);
      }
    }
  } else if(b instanceof ByteStringBuffer ||
    (typeof b === 'object' && typeof b.data === 'string' &&
    typeof b.read === 'number')) {
    // copy existing buffer
    this.data = b.data;
    this.read = b.read;
  }
}
util.ByteStringBuffer = ByteStringBuffer;

/**
 * Gets the number of bytes in this buffer.
 *
 * @return the number of bytes in this buffer.
 */
util.ByteStringBuffer.prototype.length = function() {
  return this.data.length - this.read;
};

/**
 * Gets whether or not this buffer is empty.
 *
 * @return true if this buffer is empty, false if not.
 */
util.ByteStringBuffer.prototype.isEmpty = function() {
  return this.length() <= 0;
};

/**
 * Puts a byte in this buffer.
 *
 * @param b the byte to put.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putByte = function(b) {
  this.data += String.fromCharCode(b);
  return this;
};

/**
 * Puts a byte in this buffer N times.
 *
 * @param b the byte to put.
 * @param n the number of bytes of value b to put.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.fillWithByte = function(b, n) {
  b = String.fromCharCode(b);
  var d = this.data;
  while(n > 0) {
    if(n & 1) {
      d += b;
    }
    n >>>= 1;
    if(n > 0) {
      b += b;
    }
  }
  this.data = d;
  return this;
};

/**
 * Puts bytes in this buffer.
 *
 * @param bytes the bytes (as a UTF-8 encoded string) to put.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putBytes = function(bytes) {
  // TODO: update to match DataBuffer API
  this.data += bytes;
  return this;
};

/**
 * Puts a UTF-16 encoded string into this buffer.
 *
 * @param str the string to put.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putString = function(str) {
  this.data += util.encodeUtf8(str);
  return this;
};

/**
 * Puts a 16-bit integer in this buffer in big-endian order.
 *
 * @param i the 16-bit integer.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putInt16 = function(i) {
  this.data +=
    String.fromCharCode(i >> 8 & 0xFF) +
    String.fromCharCode(i & 0xFF);
  return this;
};

/**
 * Puts a 24-bit integer in this buffer in big-endian order.
 *
 * @param i the 24-bit integer.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putInt24 = function(i) {
  this.data +=
    String.fromCharCode(i >> 16 & 0xFF) +
    String.fromCharCode(i >> 8 & 0xFF) +
    String.fromCharCode(i & 0xFF);
  return this;
};

/**
 * Puts a 32-bit integer in this buffer in big-endian order.
 *
 * @param i the 32-bit integer.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putInt32 = function(i) {
  this.data +=
    String.fromCharCode(i >> 24 & 0xFF) +
    String.fromCharCode(i >> 16 & 0xFF) +
    String.fromCharCode(i >> 8 & 0xFF) +
    String.fromCharCode(i & 0xFF);
  return this;
};

/**
 * Puts a 16-bit integer in this buffer in little-endian order.
 *
 * @param i the 16-bit integer.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putInt16Le = function(i) {
  this.data +=
    String.fromCharCode(i & 0xFF) +
    String.fromCharCode(i >> 8 & 0xFF);
  return this;
};

/**
 * Puts a 24-bit integer in this buffer in little-endian order.
 *
 * @param i the 24-bit integer.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putInt24Le = function(i) {
  this.data +=
    String.fromCharCode(i & 0xFF) +
    String.fromCharCode(i >> 8 & 0xFF) +
    String.fromCharCode(i >> 16 & 0xFF);
  return this;
};

/**
 * Puts a 32-bit integer in this buffer in little-endian order.
 *
 * @param i the 32-bit integer.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putInt32Le = function(i) {
  this.data +=
    String.fromCharCode(i & 0xFF) +
    String.fromCharCode(i >> 8 & 0xFF) +
    String.fromCharCode(i >> 16 & 0xFF) +
    String.fromCharCode(i >> 24 & 0xFF);
  return this;
};

/**
 * Puts an n-bit integer in this buffer in big-endian order.
 *
 * @param i the n-bit integer.
 * @param n the number of bits in the integer.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putInt = function(i, n) {
  do {
    n -= 8;
    this.data += String.fromCharCode((i >> n) & 0xFF);
  } while(n > 0);
  return this;
};

/**
 * Puts a signed n-bit integer in this buffer in big-endian order. Two's
 * complement representation is used.
 *
 * @param i the n-bit integer.
 * @param n the number of bits in the integer.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putSignedInt = function(i, n) {
  if(i < 0) {
    i += 2 << (n - 1);
  }
  return this.putInt(i, n);
};

/**
 * Puts the given buffer into this buffer.
 *
 * @param buffer the buffer to put into this one.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.putBuffer = function(buffer) {
  this.data += buffer.getBytes();
  return this;
};

/**
 * Gets a byte from this buffer and advances the read pointer by 1.
 *
 * @return the byte.
 */
util.ByteStringBuffer.prototype.getByte = function() {
  return this.data.charCodeAt(this.read++);
};

/**
 * Gets a uint16 from this buffer in big-endian order and advances the read
 * pointer by 2.
 *
 * @return the uint16.
 */
util.ByteStringBuffer.prototype.getInt16 = function() {
  var rval = (
    this.data.charCodeAt(this.read) << 8 ^
    this.data.charCodeAt(this.read + 1));
  this.read += 2;
  return rval;
};

/**
 * Gets a uint24 from this buffer in big-endian order and advances the read
 * pointer by 3.
 *
 * @return the uint24.
 */
util.ByteStringBuffer.prototype.getInt24 = function() {
  var rval = (
    this.data.charCodeAt(this.read) << 16 ^
    this.data.charCodeAt(this.read + 1) << 8 ^
    this.data.charCodeAt(this.read + 2));
  this.read += 3;
  return rval;
};

/**
 * Gets a uint32 from this buffer in big-endian order and advances the read
 * pointer by 4.
 *
 * @return the word.
 */
util.ByteStringBuffer.prototype.getInt32 = function() {
  var rval = (
    this.data.charCodeAt(this.read) << 24 ^
    this.data.charCodeAt(this.read + 1) << 16 ^
    this.data.charCodeAt(this.read + 2) << 8 ^
    this.data.charCodeAt(this.read + 3));
  this.read += 4;
  return rval;
};

/**
 * Gets a uint16 from this buffer in little-endian order and advances the read
 * pointer by 2.
 *
 * @return the uint16.
 */
util.ByteStringBuffer.prototype.getInt16Le = function() {
  var rval = (
    this.data.charCodeAt(this.read) ^
    this.data.charCodeAt(this.read + 1) << 8);
  this.read += 2;
  return rval;
};

/**
 * Gets a uint24 from this buffer in little-endian order and advances the read
 * pointer by 3.
 *
 * @return the uint24.
 */
util.ByteStringBuffer.prototype.getInt24Le = function() {
  var rval = (
    this.data.charCodeAt(this.read) ^
    this.data.charCodeAt(this.read + 1) << 8 ^
    this.data.charCodeAt(this.read + 2) << 16);
  this.read += 3;
  return rval;
};

/**
 * Gets a uint32 from this buffer in little-endian order and advances the read
 * pointer by 4.
 *
 * @return the word.
 */
util.ByteStringBuffer.prototype.getInt32Le = function() {
  var rval = (
    this.data.charCodeAt(this.read) ^
    this.data.charCodeAt(this.read + 1) << 8 ^
    this.data.charCodeAt(this.read + 2) << 16 ^
    this.data.charCodeAt(this.read + 3) << 24);
  this.read += 4;
  return rval;
};

/**
 * Gets an n-bit integer from this buffer in big-endian order and advances the
 * read pointer by n/8.
 *
 * @param n the number of bits in the integer.
 *
 * @return the integer.
 */
util.ByteStringBuffer.prototype.getInt = function(n) {
  var rval = 0;
  do {
    rval = (rval << 8) + this.data.charCodeAt(this.read++);
    n -= 8;
  } while(n > 0);
  return rval;
};

/**
 * Gets a signed n-bit integer from this buffer in big-endian order, using
 * two's complement, and advances the read pointer by n/8.
 *
 * @param n the number of bits in the integer.
 *
 * @return the integer.
 */
util.ByteStringBuffer.prototype.getSignedInt = function(n) {
  var x = this.getInt(n);
  var max = 2 << (n - 2);
  if(x >= max) {
    x -= max << 1;
  }
  return x;
};

/**
 * Reads bytes out into a UTF-8 string and clears them from the buffer.
 *
 * @param count the number of bytes to read, undefined or null for all.
 *
 * @return a UTF-8 string of bytes.
 */
util.ByteStringBuffer.prototype.getBytes = function(count) {
  var rval;
  if(count) {
    // read count bytes
    count = Math.min(this.length(), count);
    rval = this.data.slice(this.read, this.read + count);
    this.read += count;
  } else if(count === 0) {
    rval = '';
  } else {
    // read all bytes, optimize to only copy when needed
    rval = (this.read === 0) ? this.data : this.data.slice(this.read);
    this.clear();
  }
  return rval;
};

/**
 * Gets a UTF-8 encoded string of the bytes from this buffer without modifying
 * the read pointer.
 *
 * @param count the number of bytes to get, omit to get all.
 *
 * @return a string full of UTF-8 encoded characters.
 */
util.ByteStringBuffer.prototype.bytes = function(count) {
  return (typeof(count) === 'undefined' ?
    this.data.slice(this.read) :
    this.data.slice(this.read, this.read + count));
};

/**
 * Gets a byte at the given index without modifying the read pointer.
 *
 * @param i the byte index.
 *
 * @return the byte.
 */
util.ByteStringBuffer.prototype.at = function(i) {
  return this.data.charCodeAt(this.read + i);
};

/**
 * Puts a byte at the given index without modifying the read pointer.
 *
 * @param i the byte index.
 * @param b the byte to put.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.setAt = function(i, b) {
  this.data = this.data.substr(0, this.read + i) +
    String.fromCharCode(b) +
    this.data.substr(this.read + i + 1);
  return this;
};

/**
 * Gets the last byte without modifying the read pointer.
 *
 * @return the last byte.
 */
util.ByteStringBuffer.prototype.last = function() {
  return this.data.charCodeAt(this.data.length - 1);
};

/**
 * Creates a copy of this buffer.
 *
 * @return the copy.
 */
util.ByteStringBuffer.prototype.copy = function() {
  var c = util.createBuffer(this.data);
  c.read = this.read;
  return c;
};

/**
 * Compacts this buffer.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.compact = function() {
  if(this.read > 0) {
    this.data = this.data.slice(this.read);
    this.read = 0;
  }
  return this;
};

/**
 * Clears this buffer.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.clear = function() {
  this.data = '';
  this.read = 0;
  return this;
};

/**
 * Shortens this buffer by triming bytes off of the end of this buffer.
 *
 * @param count the number of bytes to trim off.
 *
 * @return this buffer.
 */
util.ByteStringBuffer.prototype.truncate = function(count) {
  var len = Math.max(0, this.length() - count);
  this.data = this.data.substr(this.read, len);
  this.read = 0;
  return this;
};

/**
 * Converts this buffer to a hexadecimal string.
 *
 * @return a hexadecimal string.
 */
util.ByteStringBuffer.prototype.toHex = function() {
  var rval = '';
  for(var i = this.read; i < this.data.length; ++i) {
    var b = this.data.charCodeAt(i);
    if(b < 16) {
      rval += '0';
    }
    rval += b.toString(16);
  }
  return rval;
};

/**
 * Converts this buffer to a UTF-16 string (standard JavaScript string).
 *
 * @return a UTF-16 string.
 */
util.ByteStringBuffer.prototype.toString = function() {
  return util.decodeUtf8(this.bytes());
};

/** End Buffer w/BinaryString backing */

/**
 * Creates a buffer that stores bytes. A value may be given to put into the
 * buffer that is either a string of bytes or a UTF-16 string that will
 * be encoded using UTF-8 (to do the latter, specify 'utf8' as the encoding).
 *
 * @param [input] the bytes to wrap (as a string) or a UTF-16 string to encode
 *          as UTF-8.
 * @param [encoding] (default: 'raw', other: 'utf8').
 */
util.createBuffer = function(input, encoding) {
  // TODO: deprecate, use new ByteBuffer() instead
  encoding = encoding || 'raw';
  if(input !== undefined && encoding === 'utf8') {
    input = util.encodeUtf8(input);
  }
  return new util.ByteBuffer(input);
};

/**
 * Fills a string with a particular value. If you want the string to be a byte
 * string, pass in String.fromCharCode(theByte).
 *
 * @param c the character to fill the string with, use String.fromCharCode
 *          to fill the string with a byte value.
 * @param n the number of characters of value c to fill with.
 *
 * @return the filled string.
 */
util.fillString = function(c, n) {
  var s = '';
  while(n > 0) {
    if(n & 1) {
      s += c;
    }
    n >>>= 1;
    if(n > 0) {
      c += c;
    }
  }
  return s;
};

/**
 * UTF-8 encodes the given UTF-16 encoded string (a standard JavaScript
 * string). Non-ASCII characters will be encoded as multiple bytes according
 * to UTF-8.
 *
 * @param str the string to encode.
 *
 * @return the UTF-8 encoded string.
 */
util.encodeUtf8 = function(str) {
  return unescape(encodeURIComponent(str));
};

} // end module implementation

/* ########## Begin module wrapper ########## */
var name = 'util';
if(typeof define !== 'function') {
  // NodeJS -> AMD
  if(typeof module === 'object' && module.exports) {
    var nodeJS = true;
    define = function(ids, factory) {
      factory(require, module);
    };
  } else {
    // <script>
    if(typeof forge === 'undefined') {
      forge = {};
    }
    return initModule(forge);
  }
}
// AMD
var deps;
var defineFunc = function(require, module) {
  module.exports = function(forge) {
    var mods = deps.map(function(dep) {
      return require(dep);
    }).concat(initModule);
    // handle circular dependencies
    forge = forge || {};
    forge.defined = forge.defined || {};
    if(forge.defined[name]) {
      return forge[name];
    }
    forge.defined[name] = true;
    for(var i = 0; i < mods.length; ++i) {
      mods[i](forge);
    }
    return forge[name];
  };
};
var tmpDefine = define;
define = function(ids, factory) {
  deps = (typeof ids === 'string') ? factory.slice(2) : ids.slice(2);
  if(nodeJS) {
    delete define;
    return tmpDefine.apply(null, Array.prototype.slice.call(arguments, 0));
  }
  define = tmpDefine;
  return define.apply(null, Array.prototype.slice.call(arguments, 0));
};
define(['require', 'module'], function() {
  defineFunc.apply(null, Array.prototype.slice.call(arguments, 0));
});
})();