#Uuid generator php code#
#Uuid generator php mac#

The namespace is either a UUID in string representation or an identifier for internally pre-defined namespace UUIDs (currently known are 'ns:DNS', 'ns:URL', 'ns:OID', and 'ns:X500'). Now you can have calls: uuid = NameToUUID(Namespace_DNS, 'uuid = NameToUUID(Namespace_DNS, 'uuid = NameToUUID(Namespace_URL, '') įor version 3 and version 5 UUIDs the additional command line arguments namespace and name have to be given. (Note: the endian-ness of your system can affect indices of the above bytes) set high-nibble to 5 to indicate type 5 Copy first 16-bytes of the hash into our Uuid result

#Uuid generator php code#

Note: All code on stackoverflow is public domain - no attribution required.īyte hash = sha1(NamespaceUUID.ToBytes() + Name.ToBytes()) Now that you have a function that generates a so-called Name, you can have the function (in pseudo-code): UUID NameToUUID(UUID NamespaceUUID, String Name) The basic gist is to only take the first 128 bits, stuff a 5 in the type record, and then set the first two bits of the clock_seq_hi_and_reserved section to 1 and 0, respectively. StackOverflowUrlUUID = sha1(Namespace_URL + '') So, you could hash together: StackOverflowDnsUUID = sha1(Namespace_DNS + '') The UUID RFC pre-defines four namespaces for you:

You prefix your string with a so-called namespace to prevent name conflicts. You're probably wondering what is it that I'm supposed to hash. ╰─low nibble is set to 5, to indicate type 5 ⭡ ⬑first two bits set to 1 and 0, respectively

Type 6: unofficial idea for sequential UUIDsĮdit: Unofficial type 6 now has an official rfcĪn SHA1 hash outputs 160 bits (20 bytes) the result of the hash is converted into a UUID.

Type 5: stuffs an SHA1 hash into 128 bits.

Type 4: stuffs random data into 128 bits.

Type 3: stuffs an MD5 hash into 128 bits.

#Uuid generator php mac#

Type 1: stuffs MAC address+ datetime into 128 bits.* clock_seq_hi_and_reserved to zero and one, respectively.Type 3 and Type 5 UUIDs are just a technique of stuffing a hash into a UUID: * Set the two most significant bits (bits 6 and 7) of the $time_hi_and_version = $time_hi_and_version | 0x4000 $time_hi_and_version = $time_hi_and_version > 4 $time_hi_and_version = hexdec($time_hi_and_version) * time_hi_and_version field to the 4-bit version number from * Set the four most significant bits (bits 12 through 15) of the $node = bin2hex(substr($randomString, 10, 6)) $clock_seq_hi_and_reserved = bin2hex(substr($randomString, 8, 2)) $time_hi_and_version = bin2hex(substr($randomString, 6, 2)) $time_mid = bin2hex(substr($randomString, 4, 2)) $time_low = bin2hex(substr($randomString, 0, 4)) $randomString = openssl_random_pseudo_bytes(16) My answer is based on comment uniqid user comment but it uses openssl_random_pseudo_bytes function to generate random string instead of reading from /dev/urandom function guid() With PHP 7, generating random byte sequences is even simpler using random_bytes(): function guidv4($data = null) The following approach generates 128 bits of random data using openssl_random_pseudo_bytes(), makes the permutations on the octets and then uses bin2hex() and vsprintf() to do the final formatting. clock_seq_hi_and_reserved (bit 6 & 7 of 9th octet)Īll of the other 122 bits should be sufficiently random.time_hi_and_version (bits 4-7 of 7th octet),.You should also use a better random number generator than mt_rand().Īccording to RFC 4122 - Section 4.4, you need to change these fields: Instead of breaking it down into individual fields, it's easier to generate a random block of data and change the individual byte positions. I was hoping someone with more knowledge than me in this area could lend me a hand and help me fix this function so it does adhere to that rule. This is where the functions fails as it doesn't adhere to that.

This function generates a valid v4 UUID up until one area. My knowledge in hex, decimal, binary, PHP's bitwise operators and the like is nearly nonexistent. This is the closest I've been able to come. So I've been doing some digging around and I've been trying to piece together a function that generates a valid v4 UUID in PHP.