x.websockets: new websockets module on top of x.net (#6189)

vlib/x/websocket/utils.v

@@ -0,0 +1,52 @@
+module websocket
+
+import rand
+import crypto.sha1
+import encoding.base64
+
+fn htonl64(payload_len u64) []byte {
+	mut ret := []byte{len: 8}
+	ret[0] = byte(((payload_len & (u64(0xff) << 56)) >> 56) & 0xff)
+	ret[1] = byte(((payload_len & (u64(0xff) << 48)) >> 48) & 0xff)
+	ret[2] = byte(((payload_len & (u64(0xff) << 40)) >> 40) & 0xff)
+	ret[3] = byte(((payload_len & (u64(0xff) << 32)) >> 32) & 0xff)
+	ret[4] = byte(((payload_len & (u64(0xff) << 24)) >> 24) & 0xff)
+	ret[5] = byte(((payload_len & (u64(0xff) << 16)) >> 16) & 0xff)
+	ret[6] = byte(((payload_len & (u64(0xff) << 8)) >> 8) & 0xff)
+	ret[7] = byte(((payload_len & (u64(0xff) << 0)) >> 0) & 0xff)
+	return ret
+}
+
+fn create_masking_key() []byte {
+	mask_bit := byte(rand.intn(255))
+	buf := []byte{len: 4, init: `0`}
+	unsafe {
+		C.memcpy(buf.data, &mask_bit, 4)
+	}
+	return buf
+}
+
+fn create_key_challenge_response(seckey string) ?string {
+	if seckey.len == 0 {
+		return error('unexpected seckey lengt zero')
+	}
+	guid := '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
+	sha1buf := seckey + guid
+	shabytes := sha1buf.bytes()
+	hash := sha1.sum(shabytes)
+	b64 := base64.encode(tos(hash.data, hash.len))
+	unsafe {
+		hash.free()
+		shabytes.free()
+	}
+	return b64
+}
+
+fn get_nonce(nonce_size int) string {
+	mut nonce := []byte{len: nonce_size, cap: nonce_size}
+	alphanum := '0123456789ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvwxyz'
+	for i in 0 .. nonce_size {
+		nonce[i] = alphanum[rand.intn(alphanum.len)]
+	}
+	return tos(nonce.data, nonce.len).clone()
+}