cryptokit.hash.swift

var hasher = SHA256()
let path = Bundle.main.path(forResource: "video", ofType: "mp4")!
let stream = InputStream(fileAtPath: path)!
stream.open()

let bufferSize = 512
let buffer = UnsafeMutablePointer<UInt8>.allocate(capacity: bufferSize)

while stream.hasBytesAvailable {
    let read = stream.read(buffer, maxLength: bufferSize)
    let bufferPointer = UnsafeRawBufferPointer(start: buffer, count: read)
    hasher.update(bufferPointer: bufferPointer)
}

let digest = hasher.finalize()
print(digest)