First commit

node_modules/@ldapjs/dn/lib/utils/escape-value.js

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+'use strict'
+
+/**
+ * Converts an attribute value into an escaped string as described in
+ * https://www.rfc-editor.org/rfc/rfc4514#section-2.4.
+ *
+ * This function supports up to 4 byte unicode characters.
+ *
+ * @param {string} value
+ * @returns {string} The escaped string.
+ */
+module.exports = function escapeValue (value) {
+  if (typeof value !== 'string') {
+    throw Error('value must be a string')
+  }
+
+  const toEscape = Buffer.from(value, 'utf8')
+  const escaped = []
+
+  // We will handle the reverse solidus ('\') on its own.
+  const embeddedReservedChars = [
+    0x22, // '"'
+    0x2b, // '+'
+    0x2c, // ','
+    0x3b, // ';'
+    0x3c, // '<'
+    0x3e // '>'
+  ]
+  for (let i = 0; i < toEscape.byteLength;) {
+    const charHex = toEscape[i]
+
+    // Handle leading space or #.
+    if (i === 0 && (charHex === 0x20 || charHex === 0x23)) {
+      escaped.push(toEscapedHexString(charHex))
+      i += 1
+      continue
+    }
+    // Handle trailing space.
+    if (i === toEscape.byteLength - 1 && charHex === 0x20) {
+      escaped.push(toEscapedHexString(charHex))
+      i += 1
+      continue
+    }
+
+    if (embeddedReservedChars.includes(charHex) === true) {
+      escaped.push(toEscapedHexString(charHex))
+      i += 1
+      continue
+    }
+
+    if (charHex >= 0xc0 && charHex <= 0xdf) {
+      // Represents the first byte in a 2-byte UTF-8 character.
+      escaped.push(toEscapedHexString(charHex))
+      escaped.push(toEscapedHexString(toEscape[i + 1]))
+      i += 2
+      continue
+    }
+
+    if (charHex >= 0xe0 && charHex <= 0xef) {
+      // Represents the first byte in a 3-byte UTF-8 character.
+      escaped.push(toEscapedHexString(charHex))
+      escaped.push(toEscapedHexString(toEscape[i + 1]))
+      escaped.push(toEscapedHexString(toEscape[i + 2]))
+      i += 3
+      continue
+    }
+
+    if (charHex >= 0xf0 && charHex <= 0xf7) {
+      // Represents the first byte in a 4-byte UTF-8 character.
+      escaped.push(toEscapedHexString(charHex))
+      escaped.push(toEscapedHexString(toEscape[i + 1]))
+      escaped.push(toEscapedHexString(toEscape[i + 2]))
+      escaped.push(toEscapedHexString(toEscape[i + 3]))
+      i += 4
+      continue
+    }
+
+    if (charHex <= 31) {
+      // Represents an ASCII control character.
+      escaped.push(toEscapedHexString(charHex))
+      i += 1
+      continue
+    }
+
+    escaped.push(String.fromCharCode(charHex))
+    i += 1
+    continue
+  }
+
+  return escaped.join('')
+}
+
+/**
+ * Given a byte, convert it to an escaped hex string.
+ *
+ * @example
+ * toEscapedHexString(0x20) // '\20'
+ *
+ * @param {number} char
+ * @returns {string}
+ */
+function toEscapedHexString (char) {
+  return '\\' + char.toString(16).padStart(2, '0')
+}