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rand(2), cons(3): clarify /dev/random behaviour

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This commit is contained in:
cinap_lenrek 2016-08-27 21:27:52 +02:00
parent f777743b72
commit b59aa67922
2 changed files with 4 additions and 11 deletions
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4
sys/man/2/rand
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@ -109,10 +109,6 @@ starting state.
.I Truerand .I Truerand
returns a random unsigned long read from returns a random unsigned long read from
.BR /dev/random . .BR /dev/random .
Due to the nature of
.BR /dev/random ,
truerand can only return a few hundred bits a
second.
.PP .PP
.I Ntruerand .I Ntruerand
returns a uniform random integer returns a uniform random integer

11
sys/man/3/cons
View file

@ -114,13 +114,10 @@ The hostowner also has group permissions for any local devices.
.PP .PP
Reads from Reads from
.B random .B random
return a stream of random numbers. The numbers are return a stream of random bytes produced by the kernels cryptographic
generated by a low priority kernel process that loops random number generator. The rate at which data can be read depends on
incrementing a variable. Each clock tick the variable the implementation and can vary from hundreds of megabytes to just
is sampled and, if it has changed sufficiently, the last a few hundred bits a second. Therefore,
few bits are appended to a buffer. This process is inefficient
at best producing at most a few hundred bits a second.
Therefore,
.B random .B random
should be treated as a seed to should be treated as a seed to
pseudo-random number generators which can produce a faster pseudo-random number generators which can produce a faster