openssl-rand - generate pseudo-random bytes
openssl rand [-help] [-out file]
[-base64] [-hex] [-engine id] [-rand
files] [-writerand file] [-provider name]
[-provider-path path] [-provparam
[name:]key=value] [-propquery propq]
num[K|M|G|T]
This command generates num random bytes using a
cryptographically secure pseudo random number generator (CSPRNG). A suffix
[K|M|G|T] may be appended to the num value to indicate the requested value
be scaled as a multiple of KiB/MiB/GiB/TiB respectively. Note that suffixes
are case sensitive, and that the suffixes represent binary multiples (K =
1024 bytes, M = 1024*1024 bytes, etc).
The string 'max' may be substituted for a numerical value in num,
to request the maximum number of bytes the CSPRNG can produce per
instantiation. Currently, this is restricted to 2^61 bytes as per NIST SP
800-90C.
The random bytes are generated using the RAND_bytes(3)
function, which provides a security level of 256 bits, provided it managed
to seed itself successfully from a trusted operating system entropy source.
Otherwise, the command will fail with a nonzero error code. For more
details, see RAND_bytes(3), RAND(7), and
EVP_RAND(7).
openssl(1), RAND_bytes(3), RAND(7),
EVP_RAND(7)
The -engine option was deprecated in OpenSSL 3.0.
Copyright 2000-2021 The OpenSSL Project Authors. All Rights
Reserved.
Licensed under the Apache License 2.0 (the "License").
You may not use this file except in compliance with the License. You can
obtain a copy in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
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