table of contents
CRYPTSETUP-BENCHMARK(8) | Maintenance Commands | CRYPTSETUP-BENCHMARK(8) |
NAME¶
cryptsetup-benchmark - benchmarks ciphers and KDF
SYNOPSIS¶
cryptsetup benchmark [<options>]
DESCRIPTION¶
Benchmarks ciphers and KDF (key derivation function). Without parameters, it tries to measure few common configurations.
To benchmark other ciphers or modes, you need to specify --cipher and --key-size options.
To benchmark PBKDF you need to specify --pbkdf or --hash with optional cost parameters --iter-time, --pbkdf-memory or --pbkdf-parallel.
NOTE: This benchmark uses memory only and is only informative. You cannot directly predict real storage encryption speed from it.
For testing block ciphers, this benchmark requires kernel userspace crypto API to be available (introduced in Linux kernel 2.6.38). If you are configuring kernel yourself, enable "User-space interface for symmetric key cipher algorithms" in "Cryptographic API" section (CRYPTO_USER_API_SKCIPHER .config option).
<options> can be [--cipher, --key-size, --hash, --pbkdf, --iter-time, --pbkdf-memory, --pbkdf-parallel].
OPTIONS¶
--batch-mode, -q
If the --verify-passphrase option is not specified, this option also switches off the passphrase verification.
--cipher, -c <cipher-spec>
--debug or --debug-json
If --debug-json is used, additional LUKS2 JSON data structures are printed.
--hash, -h <hash-spec>
--help, -?
--iter-time, -i <number of milliseconds>
--key-size, -s bits
See /proc/crypto for more information. Note that key-size in /proc/crypto is stated in bytes.
This option can be used for open --type plain or luksFormat. All other LUKS actions will use the key-size specified in the LUKS header. Use cryptsetup --help to show the compiled-in defaults.
--pbkdf <PBKDF spec>
For LUKS1, only PBKDF2 is accepted (no need to use this option). The default PBKDF for LUKS2 is set during compilation time and is available in cryptsetup --help output.
A PBKDF is used for increasing dictionary and brute-force attack cost for keyslot passwords. The parameters can be time, memory and parallel cost.
For PBKDF2, only time cost (number of iterations) applies. For Argon2i/id, there is also memory cost (memory required during the process of key derivation) and parallel cost (number of threads that run in parallel during the key derivation.
Note that increasing memory cost also increases time, so the final parameter values are measured by a benchmark. The benchmark tries to find iteration time (--iter-time) with required memory cost --pbkdf-memory. If it is not possible, the memory cost is decreased as well. The parallel cost --pbkdf-parallel is constant and is checked against available CPU cores.
You can see all PBKDF parameters for particular LUKS2 keyslot with cryptsetup-luksDump(8) command.
NOTE: If you do not want to use benchmark and want to specify all parameters directly, use --pbkdf-force-iterations with --pbkdf-memory and --pbkdf-parallel. This will override the values without benchmarking. Note it can cause extremely long unlocking time or cause out-of-memory conditions with unconditional process termination. Use only in specific cases, for example, if you know that the formatted device will be used on some small embedded system.
MINIMAL AND MAXIMAL PBKDF COSTS: For PBKDF2, the minimum iteration count is 1000 and maximum is 4294967295 (maximum for 32bit unsigned integer). Memory and parallel costs are unused for PBKDF2. For Argon2i and Argon2id, minimum iteration count (CPU cost) is 4 and maximum is 4294967295 (maximum for 32bit unsigned integer). Minimum memory cost is 32 KiB and maximum is 4 GiB. (Limited by addressable memory on some CPU platforms.) If the memory cost parameter is benchmarked (not specified by a parameter) it is always in range from 64 MiB to 1 GiB. The parallel cost minimum is 1 and maximum 4 (if enough CPUs cores are available, otherwise it is decreased).
--pbkdf-memory <number>
--pbkdf-parallel <number>
--usage
--version, -V
REPORTING BUGS¶
Report bugs at cryptsetup mailing list <cryptsetup@lists.linux.dev> or in Issues project section <https://gitlab.com/cryptsetup/cryptsetup/-/issues/new>.
Please attach output of the failed command with --debug option added.
SEE ALSO¶
Cryptsetup FAQ <https://gitlab.com/cryptsetup/cryptsetup/wikis/FrequentlyAskedQuestions>
CRYPTSETUP¶
Part of cryptsetup project <https://gitlab.com/cryptsetup/cryptsetup/>.
2024-09-13 | cryptsetup 2.7.5 |