ndhc/duiaid.h

// Copyright 2014-2022 Nicholas J. Kain <njkain at gmail dot com>
// SPDX-License-Identifier: MIT
#ifndef NJK_NDHC_DUIAID_H_
#define NJK_NDHC_DUIAID_H_

#include "ndhc.h"

void get_clientid(struct client_config_t *cc);

#endif
Use the HWRNG for generating DUIDs and IAIDs. Before these were generated from a freshly seeded PRNG which reduces the state space of possible DUIDs and skews the distribution of both DUIDs and IAIDs as a function of the PRNG choice. None of this really matters much in practice, but do things right. 2022-08-28 13:22:44 +05:30			`// Copyright 2014-2022 Nicholas J. Kain <njkain at gmail dot com>`
Relicense as MIT. It's a lot more common than BSD 2-clause it is both compatible and nearly identical in effect. 2022-02-07 06:35:29 +05:30			`// SPDX-License-Identifier: MIT`
Support RFC4361. RFC4361 requires clients to send a clientid, and specifies that by default that clientid should be a combination of a machine-static DUID and an interface-static IAID. There are several RFC-compliant DUIDs. ndhc uses RFC6355's DUID-UUID, but chooses not to follow RFC4122 for the UUID and instead simply uses random bytes from its combined Tausworthe PRNG. RFC4122 is excessively complex, and 128-bit random values are more than sufficiently collision-resistant on even large DHCP segments. ndhc requires a read/writable directory to store the DUID/IAID states. By default this directory is /etc/ndhc. It exists outside the chroot. The DUID will be stored in a single file, DUID. The IAIDs exist per-interface and are stored in files with names similar to IAID-xx:xx:xx:xx:xx:xx, where the xx values are replaced by the Ethernet hardware address of the interface. If it is impossible to read or store the DUIDs or IAIDs, ndhc will fail at start time before it performs any network activity or forks any subprocesses. If the host system lacks volatile storage, then a clientid should manually be specified using the -c or --clientid command arguments. 2014-03-19 10:12:32 +05:30			`#ifndef NJK_NDHC_DUIAID_H_`
			`#define NJK_NDHC_DUIAID_H_`

			`#include "ndhc.h"`

Use the HWRNG for generating DUIDs and IAIDs. Before these were generated from a freshly seeded PRNG which reduces the state space of possible DUIDs and skews the distribution of both DUIDs and IAIDs as a function of the PRNG choice. None of this really matters much in practice, but do things right. 2022-08-28 13:22:44 +05:30			`void get_clientid(struct client_config_t *cc);`
Support RFC4361. RFC4361 requires clients to send a clientid, and specifies that by default that clientid should be a combination of a machine-static DUID and an interface-static IAID. There are several RFC-compliant DUIDs. ndhc uses RFC6355's DUID-UUID, but chooses not to follow RFC4122 for the UUID and instead simply uses random bytes from its combined Tausworthe PRNG. RFC4122 is excessively complex, and 128-bit random values are more than sufficiently collision-resistant on even large DHCP segments. ndhc requires a read/writable directory to store the DUID/IAID states. By default this directory is /etc/ndhc. It exists outside the chroot. The DUID will be stored in a single file, DUID. The IAIDs exist per-interface and are stored in files with names similar to IAID-xx:xx:xx:xx:xx:xx, where the xx values are replaced by the Ethernet hardware address of the interface. If it is impossible to read or store the DUIDs or IAIDs, ndhc will fail at start time before it performs any network activity or forks any subprocesses. If the host system lacks volatile storage, then a clientid should manually be specified using the -c or --clientid command arguments. 2014-03-19 10:12:32 +05:30
Relicense as MIT. It's a lot more common than BSD 2-clause it is both compatible and nearly identical in effect. 2022-02-07 06:35:29 +05:30			`#endif`