diff options
Diffstat (limited to 'Lib/uuid.py')
| -rw-r--r-- | Lib/uuid.py | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/Lib/uuid.py b/Lib/uuid.py index 06f81a7c338..313f2fc46cb 100644 --- a/Lib/uuid.py +++ b/Lib/uuid.py @@ -656,18 +656,20 @@ def _windll_getnode(): def _random_getnode(): """Get a random node ID.""" - # RFC 4122, $4.1.6 says "For systems with no IEEE address, a randomly or - # pseudo-randomly generated value may be used; see Section 4.5. The - # multicast bit must be set in such addresses, in order that they will - # never conflict with addresses obtained from network cards." + # RFC 9562, ยง6.10-3 says that + # + # Implementations MAY elect to obtain a 48-bit cryptographic-quality + # random number as per Section 6.9 to use as the Node ID. [...] [and] + # implementations MUST set the least significant bit of the first octet + # of the Node ID to 1. This bit is the unicast or multicast bit, which + # will never be set in IEEE 802 addresses obtained from network cards. # # The "multicast bit" of a MAC address is defined to be "the least # significant bit of the first octet". This works out to be the 41st bit # counting from 1 being the least significant bit, or 1<<40. # # See https://en.wikipedia.org/w/index.php?title=MAC_address&oldid=1128764812#Universal_vs._local_(U/L_bit) - import random - return random.getrandbits(48) | (1 << 40) + return int.from_bytes(os.urandom(6)) | (1 << 40) # _OS_GETTERS, when known, are targeted for a specific OS or platform. |