mtcute/packages/core/src/utils/buffer-utils.ts
Alina Sireneva d88bc0ea60
chore: code quality improvements
improved eslint config, fixed linter issues, added husky
2023-06-05 00:30:48 +00:00

109 lines
2.5 KiB
TypeScript

export { _randomBytes as randomBytes } from './platform/crypto'
const b64urlAvailable = Buffer.isEncoding('base64url')
// from https://github.com/feross/typedarray-to-buffer
// licensed under MIT
/**
* Convert a typed array to a Buffer.
* @param arr Typed array to convert
*/
export function typedArrayToBuffer(arr: NodeJS.TypedArray): Buffer {
return ArrayBuffer.isView(arr) ?
// To avoid a copy, use the typed array's underlying ArrayBuffer to back
// new Buffer, respecting the "view", i.e. byteOffset and byteLength
Buffer.from(arr.buffer, arr.byteOffset, arr.byteLength) :
// Pass through all other types to `Buffer.from`
Buffer.from(arr)
}
/**
* Check if two buffers are equal
*
* @param a First buffer
* @param b Second buffer
*/
export function buffersEqual(a: Buffer, b: Buffer): boolean {
if (a.length !== b.length) return false
for (let i = 0; i < a.length; i++) {
if (a[i] !== b[i]) return false
}
return true
}
/**
* Perform XOR operation on two buffers and return the new buffer
*
* @param data Buffer to XOR
* @param key Key to XOR with
*/
export function xorBuffer(data: Buffer, key: Buffer): Buffer {
const ret = Buffer.alloc(data.length)
for (let i = 0; i < data.length; i++) {
ret[i] = data[i] ^ key[i]
}
return ret
}
/**
* Perform XOR operation on two buffers in-place
*
* @param data Buffer to XOR
* @param key Key to XOR with
*/
export function xorBufferInPlace(data: Buffer, key: Buffer): void {
for (let i = 0; i < data.length; i++) {
data[i] ^= key[i]
}
}
/**
* Copy a buffer
*
* @param buf Buffer to copy
* @param start Start offset
* @param end End offset
*/
export function cloneBuffer(buf: Buffer, start = 0, end = buf.length): Buffer {
const ret = Buffer.alloc(end - start)
buf.copy(ret, 0, start, end)
return ret
}
/**
* Parse url-safe base64 string
*
* @param str String to parse
*/
export function parseUrlSafeBase64(str: string): Buffer {
if (b64urlAvailable) {
return Buffer.from(str, 'base64url')
}
str = str.replace(/-/g, '+').replace(/_/g, '/')
while (str.length % 4) str += '='
return Buffer.from(str, 'base64')
}
/**
* Convert a buffer to url-safe base64 string
*
* @param buf Buffer to convert
*/
export function encodeUrlSafeBase64(buf: Buffer): string {
if (b64urlAvailable) {
return buf.toString('base64url')
}
return buf
.toString('base64')
.replace(/\+/g, '-')
.replace(/\//g, '_')
.replace(/=+$/g, '')
}