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- "use strict"
- var Buffer = require("safer-buffer").Buffer
- // UTF-7 codec, according to https://tools.ietf.org/html/rfc2152
- // See also below a UTF-7-IMAP codec, according to http://tools.ietf.org/html/rfc3501#section-5.1.3
- exports.utf7 = Utf7Codec
- exports.unicode11utf7 = "utf7" // Alias UNICODE-1-1-UTF-7
- function Utf7Codec (codecOptions, iconv) {
- this.iconv = iconv
- };
- Utf7Codec.prototype.encoder = Utf7Encoder
- Utf7Codec.prototype.decoder = Utf7Decoder
- Utf7Codec.prototype.bomAware = true
- // -- Encoding
- // Why scape ()?./?
- // eslint-disable-next-line no-useless-escape
- var nonDirectChars = /[^A-Za-z0-9'\(\),-\.\/:\? \n\r\t]+/g
- function Utf7Encoder (options, codec) {
- this.iconv = codec.iconv
- }
- Utf7Encoder.prototype.write = function (str) {
- // Naive implementation.
- // Non-direct chars are encoded as "+<base64>-"; single "+" char is encoded as "+-".
- return Buffer.from(str.replace(nonDirectChars, function (chunk) {
- return "+" + (chunk === "+"
- ? ""
- : this.iconv.encode(chunk, "utf16-be").toString("base64").replace(/=+$/, "")) +
- "-"
- }.bind(this)))
- }
- Utf7Encoder.prototype.end = function () {
- }
- // -- Decoding
- function Utf7Decoder (options, codec) {
- this.iconv = codec.iconv
- this.inBase64 = false
- this.base64Accum = ""
- }
- // Why scape /?
- // eslint-disable-next-line no-useless-escape
- var base64Regex = /[A-Za-z0-9\/+]/
- var base64Chars = []
- for (var i = 0; i < 256; i++) { base64Chars[i] = base64Regex.test(String.fromCharCode(i)) }
- var plusChar = "+".charCodeAt(0)
- var minusChar = "-".charCodeAt(0)
- var andChar = "&".charCodeAt(0)
- Utf7Decoder.prototype.write = function (buf) {
- var res = ""; var lastI = 0
- var inBase64 = this.inBase64
- var base64Accum = this.base64Accum
- // The decoder is more involved as we must handle chunks in stream.
- for (var i = 0; i < buf.length; i++) {
- if (!inBase64) { // We're in direct mode.
- // Write direct chars until '+'
- if (buf[i] == plusChar) {
- res += this.iconv.decode(buf.slice(lastI, i), "ascii") // Write direct chars.
- lastI = i + 1
- inBase64 = true
- }
- } else { // We decode base64.
- if (!base64Chars[buf[i]]) { // Base64 ended.
- if (i == lastI && buf[i] == minusChar) { // "+-" -> "+"
- res += "+"
- } else {
- var b64str = base64Accum + this.iconv.decode(buf.slice(lastI, i), "ascii")
- res += this.iconv.decode(Buffer.from(b64str, "base64"), "utf16-be")
- }
- if (buf[i] != minusChar) // Minus is absorbed after base64.
- { i-- }
- lastI = i + 1
- inBase64 = false
- base64Accum = ""
- }
- }
- }
- if (!inBase64) {
- res += this.iconv.decode(buf.slice(lastI), "ascii") // Write direct chars.
- } else {
- var b64str = base64Accum + this.iconv.decode(buf.slice(lastI), "ascii")
- var canBeDecoded = b64str.length - (b64str.length % 8) // Minimal chunk: 2 quads -> 2x3 bytes -> 3 chars.
- base64Accum = b64str.slice(canBeDecoded) // The rest will be decoded in future.
- b64str = b64str.slice(0, canBeDecoded)
- res += this.iconv.decode(Buffer.from(b64str, "base64"), "utf16-be")
- }
- this.inBase64 = inBase64
- this.base64Accum = base64Accum
- return res
- }
- Utf7Decoder.prototype.end = function () {
- var res = ""
- if (this.inBase64 && this.base64Accum.length > 0) { res = this.iconv.decode(Buffer.from(this.base64Accum, "base64"), "utf16-be") }
- this.inBase64 = false
- this.base64Accum = ""
- return res
- }
- // UTF-7-IMAP codec.
- // RFC3501 Sec. 5.1.3 Modified UTF-7 (http://tools.ietf.org/html/rfc3501#section-5.1.3)
- // Differences:
- // * Base64 part is started by "&" instead of "+"
- // * Direct characters are 0x20-0x7E, except "&" (0x26)
- // * In Base64, "," is used instead of "/"
- // * Base64 must not be used to represent direct characters.
- // * No implicit shift back from Base64 (should always end with '-')
- // * String must end in non-shifted position.
- // * "-&" while in base64 is not allowed.
- exports.utf7imap = Utf7IMAPCodec
- function Utf7IMAPCodec (codecOptions, iconv) {
- this.iconv = iconv
- };
- Utf7IMAPCodec.prototype.encoder = Utf7IMAPEncoder
- Utf7IMAPCodec.prototype.decoder = Utf7IMAPDecoder
- Utf7IMAPCodec.prototype.bomAware = true
- // -- Encoding
- function Utf7IMAPEncoder (options, codec) {
- this.iconv = codec.iconv
- this.inBase64 = false
- this.base64Accum = Buffer.alloc(6)
- this.base64AccumIdx = 0
- }
- Utf7IMAPEncoder.prototype.write = function (str) {
- var inBase64 = this.inBase64
- var base64Accum = this.base64Accum
- var base64AccumIdx = this.base64AccumIdx
- var buf = Buffer.alloc(str.length * 5 + 10); var bufIdx = 0
- for (var i = 0; i < str.length; i++) {
- var uChar = str.charCodeAt(i)
- if (uChar >= 0x20 && uChar <= 0x7E) { // Direct character or '&'.
- if (inBase64) {
- if (base64AccumIdx > 0) {
- bufIdx += buf.write(base64Accum.slice(0, base64AccumIdx).toString("base64").replace(/\//g, ",").replace(/=+$/, ""), bufIdx)
- base64AccumIdx = 0
- }
- buf[bufIdx++] = minusChar // Write '-', then go to direct mode.
- inBase64 = false
- }
- if (!inBase64) {
- buf[bufIdx++] = uChar // Write direct character
- if (uChar === andChar) // Ampersand -> '&-'
- { buf[bufIdx++] = minusChar }
- }
- } else { // Non-direct character
- if (!inBase64) {
- buf[bufIdx++] = andChar // Write '&', then go to base64 mode.
- inBase64 = true
- }
- if (inBase64) {
- base64Accum[base64AccumIdx++] = uChar >> 8
- base64Accum[base64AccumIdx++] = uChar & 0xFF
- if (base64AccumIdx == base64Accum.length) {
- bufIdx += buf.write(base64Accum.toString("base64").replace(/\//g, ","), bufIdx)
- base64AccumIdx = 0
- }
- }
- }
- }
- this.inBase64 = inBase64
- this.base64AccumIdx = base64AccumIdx
- return buf.slice(0, bufIdx)
- }
- Utf7IMAPEncoder.prototype.end = function () {
- var buf = Buffer.alloc(10); var bufIdx = 0
- if (this.inBase64) {
- if (this.base64AccumIdx > 0) {
- bufIdx += buf.write(this.base64Accum.slice(0, this.base64AccumIdx).toString("base64").replace(/\//g, ",").replace(/=+$/, ""), bufIdx)
- this.base64AccumIdx = 0
- }
- buf[bufIdx++] = minusChar // Write '-', then go to direct mode.
- this.inBase64 = false
- }
- return buf.slice(0, bufIdx)
- }
- // -- Decoding
- function Utf7IMAPDecoder (options, codec) {
- this.iconv = codec.iconv
- this.inBase64 = false
- this.base64Accum = ""
- }
- var base64IMAPChars = base64Chars.slice()
- base64IMAPChars[",".charCodeAt(0)] = true
- Utf7IMAPDecoder.prototype.write = function (buf) {
- var res = ""; var lastI = 0
- var inBase64 = this.inBase64
- var base64Accum = this.base64Accum
- // The decoder is more involved as we must handle chunks in stream.
- // It is forgiving, closer to standard UTF-7 (for example, '-' is optional at the end).
- for (var i = 0; i < buf.length; i++) {
- if (!inBase64) { // We're in direct mode.
- // Write direct chars until '&'
- if (buf[i] == andChar) {
- res += this.iconv.decode(buf.slice(lastI, i), "ascii") // Write direct chars.
- lastI = i + 1
- inBase64 = true
- }
- } else { // We decode base64.
- if (!base64IMAPChars[buf[i]]) { // Base64 ended.
- if (i == lastI && buf[i] == minusChar) { // "&-" -> "&"
- res += "&"
- } else {
- var b64str = base64Accum + this.iconv.decode(buf.slice(lastI, i), "ascii").replace(/,/g, "/")
- res += this.iconv.decode(Buffer.from(b64str, "base64"), "utf16-be")
- }
- if (buf[i] != minusChar) // Minus may be absorbed after base64.
- { i-- }
- lastI = i + 1
- inBase64 = false
- base64Accum = ""
- }
- }
- }
- if (!inBase64) {
- res += this.iconv.decode(buf.slice(lastI), "ascii") // Write direct chars.
- } else {
- var b64str = base64Accum + this.iconv.decode(buf.slice(lastI), "ascii").replace(/,/g, "/")
- var canBeDecoded = b64str.length - (b64str.length % 8) // Minimal chunk: 2 quads -> 2x3 bytes -> 3 chars.
- base64Accum = b64str.slice(canBeDecoded) // The rest will be decoded in future.
- b64str = b64str.slice(0, canBeDecoded)
- res += this.iconv.decode(Buffer.from(b64str, "base64"), "utf16-be")
- }
- this.inBase64 = inBase64
- this.base64Accum = base64Accum
- return res
- }
- Utf7IMAPDecoder.prototype.end = function () {
- var res = ""
- if (this.inBase64 && this.base64Accum.length > 0) { res = this.iconv.decode(Buffer.from(this.base64Accum, "base64"), "utf16-be") }
- this.inBase64 = false
- this.base64Accum = ""
- return res
- }
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