1KCAPI-RNG(1) General Commands Manual KCAPI-RNG(1)
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6 kcapi-rng - Kernel Crypto API Random Number Gatherer
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9 kcapi-rng [OPTION]
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12 The kcapi-rng application provides tool to obtain random numbers from
13 the Linux kernel crypto API via the command line. The tool is similar
14 to reading /dev/hwrand with the difference that the used random number
15 generators are fully deterministic - i.e. they are DRNGs.
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17 Any potential seed data can be provided via STDIN. Some of the DRNGs
18 require seeding as they do not seed themselves. The kcapi-rng tool
19 ensures that the DRNGs are seeded by pulling the seed data from the
20 getrandom system call (or /dev/urandom if getrandom is not available).
21 The amount of seed data is defined by the DRNG itself and can be
22 reviewed by assessing /proc/crypto. The seed provided via STDIN will
23 be added to the internally-generated seed. The generated random num‐
24 bers are written to STDOUT.
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26 The following options are supported when invoking kcapi-rng:
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28 -b, --bytes BYTES
29 Generate BYTES number of random bytes.
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31 -n, --name NAME
32 The NAME argument specifies the random number generator imple‐
33 mentation to be used. The allowed random number generators are
34 defined by the Linux kernel. Currently registered ciphers can be
35 reviewed at /proc/crypto. The content of this file, however,
36 can change when new ciphers are registered. The NAME argument is
37 given directly to the Linux kernel crypto API. The chosen cipher
38 must be of type rng as marked in /proc/crypto. If this option
39 is not used, the cipher stdrng is used as default.
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41 --hex The generated random numbers are print out in hexadecimal nota‐
42 tion instead of as binary string.
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44 -v, --verbose
45 Enable a verbose operation of kcapi-rng. Using this option mul‐
46 tiple times increases the verbosity.
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48 -q, --quiet
49 Prevent the generation of any log output.
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51 -h, --help
52 Display the help text.
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54 --version
55 Display the version number of the kcapi-rng application.
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58 kcapi-enc(1) kcapi-dgst(1)
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62 2017-08-14 KCAPI-RNG(1)