1 files changed, 119 insertions, 0 deletions
diff --git a/comm/chat/protocols/matrix/lib/base-x/index.js b/comm/chat/protocols/matrix/lib/base-x/index.js
new file mode 100644
index 0000000000..5b695f1a4c
--- /dev/null
+++ b/comm/chat/protocols/matrix/lib/base-x/index.js
@@ -0,0 +1,119 @@
+'use strict'
+// base-x encoding / decoding
+// Copyright (c) 2018 base-x contributors
+// Copyright (c) 2014-2018 The Bitcoin Core developers (base58.cpp)
+// Distributed under the MIT software license, see the accompanying
+// file LICENSE or http://www.opensource.org/licenses/mit-license.php.
+// @ts-ignore
+var _Buffer = require('safe-buffer').Buffer
+function base (ALPHABET) {
+  if (ALPHABET.length >= 255) { throw new TypeError('Alphabet too long') }
+  var BASE_MAP = new Uint8Array(256)
+  for (var j = 0; j < BASE_MAP.length; j++) {
+    BASE_MAP[j] = 255
+  }
+  for (var i = 0; i < ALPHABET.length; i++) {
+    var x = ALPHABET.charAt(i)
+    var xc = x.charCodeAt(0)
+    if (BASE_MAP[xc] !== 255) { throw new TypeError(x + ' is ambiguous') }
+    BASE_MAP[xc] = i
+  }
+  var BASE = ALPHABET.length
+  var LEADER = ALPHABET.charAt(0)
+  var FACTOR = Math.log(BASE) / Math.log(256) // log(BASE) / log(256), rounded up
+  var iFACTOR = Math.log(256) / Math.log(BASE) // log(256) / log(BASE), rounded up
+  function encode (source) {
+    if (Array.isArray(source) || source instanceof Uint8Array) { source = _Buffer.from(source) }
+    if (!_Buffer.isBuffer(source)) { throw new TypeError('Expected Buffer') }
+    if (source.length === 0) { return '' }
+        // Skip & count leading zeroes.
+    var zeroes = 0
+    var length = 0
+    var pbegin = 0
+    var pend = source.length
+    while (pbegin !== pend && source[pbegin] === 0) {
+      pbegin++
+      zeroes++
+    }
+        // Allocate enough space in big-endian base58 representation.
+    var size = ((pend - pbegin) * iFACTOR + 1) >>> 0
+    var b58 = new Uint8Array(size)
+        // Process the bytes.
+    while (pbegin !== pend) {
+      var carry = source[pbegin]
+            // Apply "b58 = b58 * 256 + ch".
+      var i = 0
+      for (var it1 = size - 1; (carry !== 0 || i < length) && (it1 !== -1); it1--, i++) {
+        carry += (256 * b58[it1]) >>> 0
+        b58[it1] = (carry % BASE) >>> 0
+        carry = (carry / BASE) >>> 0
+      }
+      if (carry !== 0) { throw new Error('Non-zero carry') }
+      length = i
+      pbegin++
+    }
+        // Skip leading zeroes in base58 result.
+    var it2 = size - length
+    while (it2 !== size && b58[it2] === 0) {
+      it2++
+    }
+        // Translate the result into a string.
+    var str = LEADER.repeat(zeroes)
+    for (; it2 < size; ++it2) { str += ALPHABET.charAt(b58[it2]) }
+    return str
+  }
+  function decodeUnsafe (source) {
+    if (typeof source !== 'string') { throw new TypeError('Expected String') }
+    if (source.length === 0) { return _Buffer.alloc(0) }
+    var psz = 0
+        // Skip and count leading '1's.
+    var zeroes = 0
+    var length = 0
+    while (source[psz] === LEADER) {
+      zeroes++
+      psz++
+    }
+        // Allocate enough space in big-endian base256 representation.
+    var size = (((source.length - psz) * FACTOR) + 1) >>> 0 // log(58) / log(256), rounded up.
+    var b256 = new Uint8Array(size)
+        // Process the characters.
+    while (source[psz]) {
+            // Decode character
+      var carry = BASE_MAP[source.charCodeAt(psz)]
+            // Invalid character
+      if (carry === 255) { return }
+      var i = 0
+      for (var it3 = size - 1; (carry !== 0 || i < length) && (it3 !== -1); it3--, i++) {
+        carry += (BASE * b256[it3]) >>> 0
+        b256[it3] = (carry % 256) >>> 0
+        carry = (carry / 256) >>> 0
+      }
+      if (carry !== 0) { throw new Error('Non-zero carry') }
+      length = i
+      psz++
+    }
+        // Skip leading zeroes in b256.
+    var it4 = size - length
+    while (it4 !== size && b256[it4] === 0) {
+      it4++
+    }
+    var vch = _Buffer.allocUnsafe(zeroes + (size - it4))
+    vch.fill(0x00, 0, zeroes)
+    var j = zeroes
+    while (it4 !== size) {
+      vch[j++] = b256[it4++]
+    }
+    return vch
+  }
+  function decode (string) {
+    var buffer = decodeUnsafe(string)
+    if (buffer) { return buffer }
+    throw new Error('Non-base' + BASE + ' character')
+  }
+  return {
+    encode: encode,
+    decodeUnsafe: decodeUnsafe,
+    decode: decode
+  }
+}
+module.exports = base