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random.4: Minor wording fixes 

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
Michael Kerrisk 2016-11-11 10:41:41 +01:00
parent 311edc011a
commit 724d21bbb8
2 changed files with 15 additions and 12 deletions
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4
man2/getrandom.2
View File

@ -181,7 +181,7 @@ When reading from
.IR /dev/urandom ,
a maximum of 33554431 bytes is returned by a single call to
.BR getrandom ()
on a system where
on systems where
.I int
has a size of 32 bits.
.IP *
@ -189,7 +189,7 @@ When reading from
.IR /dev/random ,
a maximum of 512 bytes is returned.
.SS Initialization of the entropy pool
The kernel collects bits of entropy from environment.
The kernel collects bits of entropy from the environment.
When a sufficient number of random bits has been collected, the
.I /dev/urandom
entropy pool is considered to be initialized.

23
man4/random.4
View File

@ -38,10 +38,13 @@ The generator also keeps an estimate of the
number of bits of noise in the entropy pool.
From this entropy pool, random numbers are created.
.LP
Linux 3.17 and later provides the simpler and safer (see below)
Linux 3.17 and later provides the simpler and safer
.BR getrandom (2)
interface which requires no special files.
.LP
interface which requires no special files;
see the
.BR getrandom (2)
manual page for details.
When read, the
.I /dev/urandom
device returns random bytes using a pseudorandom
@ -52,7 +55,6 @@ If this is of concern in your application, use
.BR getrandom (2)
or \fI/dev/random\fP instead.
.LP
The \fI/dev/random\fP device is a legacy interface which dates back to
a time where the cryptographic primitives used in the implementation
of \fI/dev/urandom\fP were not widely trusted.
@ -60,15 +62,16 @@ It will return random bytes only within the estimated number of
bits of fresh noise in the entropy pool, blocking if necessary.
\fI/dev/random\fP is suitable for applications that need very
high quality randomness, and can afford indeterminate delays.
When the entropy pool is empty, reads from \fI/dev/random\fP will block
until additional environmental noise is gathered.
If
.BR open (2)
is called for
.I /dev/random
with the flag
.BR O_NONBLOCK ,
a subsequent
with the
.BR O_NONBLOCK
flag, a subsequent
.BR read (2)
will not block if the requested number of bytes is not available.
Instead, the available bytes are returned.
@ -79,9 +82,9 @@ will return -1 and
will be set to
.BR EAGAIN .
The flag
The
.B O_NONBLOCK
has no effect when opening
flag has no effect when opening
.IR /dev/urandom .
When calling
.BR read (2)
@ -119,7 +122,7 @@ read from both files, but it will not make reads from
The
.IR /dev/random
interface is considered a legacy interface, and
.IR /dev/urandom ,
.IR /dev/urandom
is preferred and sufficient in all use cases, with the exception of
applications which require randomness during early boot time; for
these applications,