How to create UUID type 1 in objective C (iOS) - iphone

Question

I created UUID (don't know which type) with the following code:
// Create universally unique identifier (object)
CFUUIDRef uuidObject = CFUUIDCreate(kCFAllocatorDefault);
// Get the string representation of CFUUID object.
NSString *uuidStr = (__bridge NSString *)CFUUIDCreateString(kCFAllocatorDefault, uuidObject);
CFRelease(uuidObject);
But my API that is send data to says that is not type 1 that it needs http://en.wikipedia.org/wiki/Universally_unique_identifier#Version_1_.28MAC_address.29.
How to create this type1 UUID in objC (iphone)?
I have problems making this in obj C, is it an option to use C code to generate this?

Answer 1

I've been searching for the same thing. Here it is:
uuid_generate_time
https://developer.apple.com/library/ios/documentation/System/Conceptual/ManPages_iPhoneOS/man3/uuid_generate_time.3.html
Also there's Apple source code for this function:
http://www.opensource.apple.com/source/xnu/xnu-792.13.8/libkern/uuid/uuid.c
NSString* uuidString = nil;
// Get UUID type 1
uuid_t dateUUID;
uuid_generate_time(dateUUID);
// Convert it to string
uuid_string_t unparsedUUID;
uuid_unparse_lower(dateUUID, unparsedUUID);
uuidString = [[NSString alloc] initWithUTF8String:unparsedUUID];

Answer 2

Get the MAC address first: (from developertips)
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_dl.h>
...
- (NSString *)getMacAddress
{
int mgmtInfoBase[6];
char *msgBuffer = NULL;
size_t length;
unsigned char macAddress[6];
struct if_msghdr *interfaceMsgStruct;
struct sockaddr_dl *socketStruct;
NSString *errorFlag = NULL;
// Setup the management Information Base (mib)
mgmtInfoBase[0] = CTL_NET; // Request network subsystem
mgmtInfoBase[1] = AF_ROUTE; // Routing table info
mgmtInfoBase[2] = 0;
mgmtInfoBase[3] = AF_LINK; // Request link layer information
mgmtInfoBase[4] = NET_RT_IFLIST; // Request all configured interfaces
// With all configured interfaces requested, get handle index
if ((mgmtInfoBase[5] = if_nametoindex("en0")) == 0)
errorFlag = #"if_nametoindex failure";
else
{
// Get the size of the data available (store in len)
if (sysctl(mgmtInfoBase, 6, NULL, &length, NULL, 0) < 0)
errorFlag = #"sysctl mgmtInfoBase failure";
else
{
// Alloc memory based on above call
if ((msgBuffer = malloc(length)) == NULL)
errorFlag = #"buffer allocation failure";
else
{
// Get system information, store in buffer
if (sysctl(mgmtInfoBase, 6, msgBuffer, &length, NULL, 0) < 0)
errorFlag = #"sysctl msgBuffer failure";
}
}
}
// Befor going any further...
if (errorFlag != NULL)
{
NSLog(#"Error: %#", errorFlag);
return errorFlag;
}
// Map msgbuffer to interface message structure
interfaceMsgStruct = (struct if_msghdr *) msgBuffer;
// Map to link-level socket structure
socketStruct = (struct sockaddr_dl *) (interfaceMsgStruct + 1);
// Copy link layer address data in socket structure to an array
memcpy(&macAddress, socketStruct->sdl_data + socketStruct->sdl_nlen, 6);
// Read from char array into a string object, into traditional Mac address format
NSString *macAddressString = [NSString stringWithFormat:#"%02X:%02X:%02X:%02X:%02X:%02X",
macAddress[0], macAddress[1], macAddress[2],
macAddress[3], macAddress[4], macAddress[5]];
NSLog(#"Mac Address: %#", macAddressString);
// Release the buffer memory
free(msgBuffer);
return macAddressString;
}
Then generate the UUIDv1 with the rfc4122 spec, if the spec is too long to read, you may port the code from other language, here's one that I found: https://github.com/fredriklindberg/class.uuid.php/blob/master/class.uuid.php

Answer 3

Using following function you can create dynamic UUID.
-(NSString*)getDynamicUUID
{
CFUUIDRef uuidObj = CFUUIDCreate(nil);//create a new UUID
NSString *uuidString = (NSString*)CFUUIDCreateString(nil, uuidObj);
CFRelease(uuidObj);
return uuidString;
}
Hope this helps..