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node_modules/saslprep/index.js

@@ -0,0 +1,120 @@
+'use strict'
+
+const {
+  unassigned_code_points,
+  commonly_mapped_to_nothing,
+  non_ASCII_space_characters,
+  prohibited_characters,
+  bidirectional_r_al,
+  bidirectional_l,
+} = require('./lib/memory-code-points')
+
+module.exports = saslprep
+
+// 2.1.  Mapping
+
+/**
+ * non-ASCII space characters [StringPrep, C.1.2] that can be
+ * mapped to SPACE (U+0020)
+ */
+const mapping2space = non_ASCII_space_characters
+
+/**
+ * the "commonly mapped to nothing" characters [StringPrep, B.1]
+ * that can be mapped to nothing.
+ */
+const mapping2nothing = commonly_mapped_to_nothing
+
+// utils
+const getCodePoint = character => character.codePointAt(0)
+const first = x => x[0]
+const last = x => x[x.length - 1]
+
+/**
+ * SASLprep.
+ * @param {string} input
+ * @param {object} opts
+ * @param {boolean} opts.allowUnassigned
+ */
+function saslprep(input, opts = {}) {
+  if (typeof input !== 'string') {
+    throw new TypeError('Expected string.')
+  }
+
+  if (input.length === 0) {
+    return ''
+  }
+
+  // 1. Map
+  const mapped_input = input
+    .split('')
+    .map(getCodePoint)
+    // 1.1 mapping to space
+    .map(character => (mapping2space.get(character) ? 0x20 : character))
+    // 1.2 mapping to nothing
+    .filter(character => !mapping2nothing.get(character))
+
+  // 2. Normalize
+  const normalized_input = String.fromCodePoint(...mapped_input).normalize('NFKC')
+
+  const normalized_map = normalized_input.split('').map(getCodePoint)
+
+  // 3. Prohibit
+  const hasProhibited = normalized_map.some(character =>
+    prohibited_characters.get(character)
+  )
+
+  if (hasProhibited) {
+    throw new Error(
+      'Prohibited character, see https://tools.ietf.org/html/rfc4013#section-2.3'
+    )
+  }
+
+  // Unassigned Code Points
+  if (opts.allowUnassigned !== true) {
+    const hasUnassigned = normalized_map.some(character =>
+      unassigned_code_points.get(character)
+    )
+
+    if (hasUnassigned) {
+      throw new Error(
+        'Unassigned code point, see https://tools.ietf.org/html/rfc4013#section-2.5'
+      )
+    }
+  }
+
+  // 4. check bidi
+
+  const hasBidiRAL = normalized_map
+    .some((character) => bidirectional_r_al.get(character))
+
+  const hasBidiL = normalized_map
+    .some((character) => bidirectional_l.get(character))
+
+  // 4.1 If a string contains any RandALCat character, the string MUST NOT
+  // contain any LCat character.
+  if (hasBidiRAL && hasBidiL) {
+    throw new Error(
+      'String must not contain RandALCat and LCat at the same time,' +
+      ' see https://tools.ietf.org/html/rfc3454#section-6'
+    )
+  }
+
+  /**
+   * 4.2 If a string contains any RandALCat character, a RandALCat
+   * character MUST be the first character of the string, and a
+   * RandALCat character MUST be the last character of the string.
+   */
+
+  const isFirstBidiRAL = bidirectional_r_al.get(getCodePoint(first(normalized_input)))
+  const isLastBidiRAL = bidirectional_r_al.get(getCodePoint(last(normalized_input)))
+
+  if (hasBidiRAL && !(isFirstBidiRAL && isLastBidiRAL)) {
+    throw new Error(
+      'Bidirectional RandALCat character must be the first and the last' +
+      ' character of the string, see https://tools.ietf.org/html/rfc3454#section-6'
+    )
+  }
+
+  return normalized_input
+}