CRYPTO-JS calculating the sha256 value of a file

1. To calculate the SHA256 or MD5 value of the file in the browser, the basic idea is to use the HTML5 FileReader interface to read the file into memory (Readasarraybuffer), and then get the binary contents of the file. Then get the shaa256 or MD5 value of the file.

2. Arraybuffer is a piece of memory, and the Arraybuffer object is used to represent a generic, fixed-length binary data buffer.

3. CRYPTOJS (Crypto.js) provides a variety of cryptographic algorithms for JavaScript. Currently supported algorithms include: MD5 SHA-1 SHA-256 AES Rabbit MARC4 HMAC hmac-md5 hmac-sha1 ...

New FileReader (); Reader.readasarraybuffer (file.files[0function  () {    var Wordarray = CryptoJS.lib.WordArray.create (reader.result);     var hash = cryptojs.sha256 (wordarray). toString ();};

Reference:

Https://stackoverflow.com/questions/27060248/calculate-sha-256-hash-and-b64-of-a-file-in-javascript

CRYPTO-JS calculating the sha256 value of a file