1// Copyright (C) 2019 The Android Open Source Project 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15import { 16 decode as b64Decode, 17 encode as b64Encode, 18 length as b64Len, 19} from '@protobufjs/base64'; 20import { 21 length as utf8Len, 22 read as utf8Read, 23 write as utf8Write, 24} from '@protobufjs/utf8'; 25 26import {assertTrue} from './logging'; 27 28// TextDecoder/Decoder requires the full DOM and isn't available in all types 29// of tests. Use fallback implementation from protbufjs. 30let Utf8Decoder: {decode: (buf: Uint8Array) => string}; 31let Utf8Encoder: {encode: (str: string) => Uint8Array}; 32try { 33 Utf8Decoder = new TextDecoder('utf-8'); 34 Utf8Encoder = new TextEncoder(); 35} catch (_) { 36 if (typeof process === 'undefined') { 37 // Silence the warning when we know we are running under NodeJS. 38 console.warn( 39 'Using fallback UTF8 Encoder/Decoder, This should happen only in ' + 40 'tests and NodeJS-based environments, not in browsers.', 41 ); 42 } 43 Utf8Decoder = {decode: (buf: Uint8Array) => utf8Read(buf, 0, buf.length)}; 44 Utf8Encoder = { 45 encode: (str: string) => { 46 const arr = new Uint8Array(utf8Len(str)); 47 const written = utf8Write(str, arr, 0); 48 assertTrue(written === arr.length); 49 return arr; 50 }, 51 }; 52} 53 54export function base64Encode(buffer: Uint8Array): string { 55 return b64Encode(buffer, 0, buffer.length); 56} 57 58export function base64Decode(str: string): Uint8Array { 59 // if the string is in base64url format, convert to base64 60 const b64 = str.replaceAll('-', '+').replaceAll('_', '/'); 61 const arr = new Uint8Array(b64Len(b64)); 62 const written = b64Decode(b64, arr, 0); 63 assertTrue(written === arr.length); 64 return arr; 65} 66 67// encode binary array to hex string 68export function hexEncode(bytes: Uint8Array): string { 69 return bytes.reduce( 70 (prev, cur) => prev + ('0' + cur.toString(16)).slice(-2), 71 '', 72 ); 73} 74 75export function utf8Encode(str: string): Uint8Array { 76 return Utf8Encoder.encode(str); 77} 78 79// Note: not all byte sequences can be converted to<>from UTF8. This can be 80// used only with valid unicode strings, not arbitrary byte buffers. 81export function utf8Decode(buffer: Uint8Array): string { 82 return Utf8Decoder.decode(buffer); 83} 84 85// The binaryEncode/Decode functions below allow to encode an arbitrary binary 86// buffer into a string that can be JSON-encoded. binaryEncode() applies 87// UTF-16 encoding to each byte individually. 88// Unlike utf8Encode/Decode, any arbitrary byte sequence can be converted into a 89// valid string, and viceversa. 90// This should be only used when a byte array needs to be transmitted over an 91// interface that supports only JSON serialization (e.g., postmessage to a 92// chrome extension). 93 94export function binaryEncode(buf: Uint8Array): string { 95 let str = ''; 96 for (let i = 0; i < buf.length; i++) { 97 str += String.fromCharCode(buf[i]); 98 } 99 return str; 100} 101 102export function binaryDecode(str: string): Uint8Array { 103 const buf = new Uint8Array(str.length); 104 const strLen = str.length; 105 for (let i = 0; i < strLen; i++) { 106 buf[i] = str.charCodeAt(i); 107 } 108 return buf; 109} 110 111// A function used to interpolate strings into SQL query. The only replacement 112// is done is that single quote replaced with two single quotes, according to 113// SQLite documentation: 114// https://www.sqlite.org/lang_expr.html#literal_values_constants_ 115// 116// The purpose of this function is to use in simple comparisons, to escape 117// strings used in GLOB clauses see escapeQuery function. 118export function sqliteString(str: string): string { 119 return `'${str.replaceAll("'", "''")}'`; 120} 121 122// Chat apps (including G Chat) sometimes replace ASCII characters with similar 123// looking unicode characters that break code snippets. 124// This function attempts to undo these replacements. 125export function undoCommonChatAppReplacements(str: string): string { 126 // Replace non-breaking spaces with normal spaces. 127 return str.replaceAll('\u00A0', ' '); 128} 129