| // Copyright 2015 The Vanadium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package syncbase |
| |
| import ( |
| "crypto/rand" |
| "fmt" |
| "io" |
| ) |
| |
| // UUID generates a Version 4 UUID, based on random numbers (RFC 4122). |
| // Returned as hex-encoded String in format 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'. |
| func UUID() string { |
| uuid := make([]byte, 16) |
| io.ReadFull(rand.Reader, uuid) |
| |
| // Set the version 4 bit. |
| uuid[6] = (uuid[6] & 0x0f) | 0x40 |
| |
| // Set the varint bit to 10 as required by RFC 4122. |
| uuid[8] = (uuid[8] & 0x3f) | 0x80 |
| |
| return fmt.Sprintf("%x-%x-%x-%x-%x", uuid[:4], uuid[4:6], uuid[6:8], uuid[8:10], uuid[10:]) |
| } |
