D7net
Home
Console
Upload
information
Create File
Create Folder
About
Tools
:
/
opt
/
lampp
/
share
/
openssl
/
man
/
man3
/
Filename :
RAND_get_rand_method.3
back
Copy
.\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.32 .\" .\" Standard preamble: .\" ======================================================================== .de Sh \" Subsection heading .br .if t .Sp .ne 5 .PP \fB\\$1\fR .PP .. .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. | will give a .\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used to .\" do unbreakable dashes and therefore won't be available. \*(C` and \*(C' .\" expand to `' in nroff, nothing in troff, for use with C<>. .tr \(*W-|\(bv\*(Tr .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' 'br\} .\" .\" If the F register is turned on, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . nr % 0 . rr F .\} .\" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .hy 0 .if n .na .\" .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). .\" Fear. Run. Save yourself. No user-serviceable parts. . \" fudge factors for nroff and troff .if n \{\ . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] \fP .\} .if t \{\ . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff .if n \{\ . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} .if t \{\ . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' .\} . \" troff and (daisy-wheel) nroff accents .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' .ds 8 \h'\*(#H'\(*b\h'-\*(#H' .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] .ds ae a\h'-(\w'a'u*4/10)'e .ds Ae A\h'-(\w'A'u*4/10)'E . \" corrections for vroff .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' . \" for low resolution devices (crt and lpr) .if \n(.H>23 .if \n(.V>19 \ \{\ . ds : e . ds 8 ss . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE .\} .rm #[ #] #H #V #F C .\" ======================================================================== .\" .IX Title "RAND_set_rand_method 3" .TH RAND_set_rand_method 3 "2017-05-25" "1.0.2l" "OpenSSL" .SH "NAME" RAND_set_rand_method, RAND_get_rand_method, RAND_SSLeay \- select RAND method .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& #include <openssl/rand.h> .Ve .PP .Vb 1 \& void RAND_set_rand_method(const RAND_METHOD *meth); .Ve .PP .Vb 1 \& const RAND_METHOD *RAND_get_rand_method(void); .Ve .PP .Vb 1 \& RAND_METHOD *RAND_SSLeay(void); .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" A \fB\s-1RAND_METHOD\s0\fR specifies the functions that OpenSSL uses for random number generation. By modifying the method, alternative implementations such as hardware RNGs may be used. \s-1IMPORTANT:\s0 See the \s-1NOTES\s0 section for important information about how these \s-1RAND\s0 \s-1API\s0 functions are affected by the use of \&\fB\s-1ENGINE\s0\fR \s-1API\s0 calls. .PP Initially, the default \s-1RAND_METHOD\s0 is the OpenSSL internal implementation, as returned by \fIRAND_SSLeay()\fR. .PP \&\fIRAND_set_default_method()\fR makes \fBmeth\fR the method for \s-1PRNG\s0 use. \fB\s-1NB\s0\fR: This is true only whilst no \s-1ENGINE\s0 has been set as a default for \s-1RAND\s0, so this function is no longer recommended. .PP \&\fIRAND_get_default_method()\fR returns a pointer to the current \s-1RAND_METHOD\s0. However, the meaningfulness of this result is dependent on whether the \s-1ENGINE\s0 \&\s-1API\s0 is being used, so this function is no longer recommended. .SH "THE RAND_METHOD STRUCTURE" .IX Header "THE RAND_METHOD STRUCTURE" .Vb 9 \& typedef struct rand_meth_st \& { \& void (*seed)(const void *buf, int num); \& int (*bytes)(unsigned char *buf, int num); \& void (*cleanup)(void); \& void (*add)(const void *buf, int num, int entropy); \& int (*pseudorand)(unsigned char *buf, int num); \& int (*status)(void); \& } RAND_METHOD; .Ve .PP The components point to the implementation of \fIRAND_seed()\fR, \&\fIRAND_bytes()\fR, \fIRAND_cleanup()\fR, \fIRAND_add()\fR, \fIRAND_pseudo_rand()\fR and \fIRAND_status()\fR. Each component may be \s-1NULL\s0 if the function is not implemented. .SH "RETURN VALUES" .IX Header "RETURN VALUES" \&\fIRAND_set_rand_method()\fR returns no value. \fIRAND_get_rand_method()\fR and \&\fIRAND_SSLeay()\fR return pointers to the respective methods. .SH "NOTES" .IX Header "NOTES" As of version 0.9.7, \s-1RAND_METHOD\s0 implementations are grouped together with other algorithmic APIs (eg. \s-1RSA_METHOD\s0, \s-1EVP_CIPHER\s0, etc) in \fB\s-1ENGINE\s0\fR modules. If a default \s-1ENGINE\s0 is specified for \s-1RAND\s0 functionality using an \s-1ENGINE\s0 \s-1API\s0 function, that will override any \s-1RAND\s0 defaults set using the \s-1RAND\s0 \s-1API\s0 (ie. \&\fIRAND_set_rand_method()\fR). For this reason, the \s-1ENGINE\s0 \s-1API\s0 is the recommended way to control default implementations for use in \s-1RAND\s0 and other cryptographic algorithms. .SH "SEE ALSO" .IX Header "SEE ALSO" \&\fIrand\fR\|(3), \fIengine\fR\|(3) .SH "HISTORY" .IX Header "HISTORY" \&\fIRAND_set_rand_method()\fR, \fIRAND_get_rand_method()\fR and \fIRAND_SSLeay()\fR are available in all versions of OpenSSL. .PP In the engine version of version 0.9.6, \fIRAND_set_rand_method()\fR was altered to take an \s-1ENGINE\s0 pointer as its argument. As of version 0.9.7, that has been reverted as the \s-1ENGINE\s0 \s-1API\s0 transparently overrides \s-1RAND\s0 defaults if used, otherwise \s-1RAND\s0 \s-1API\s0 functions work as before. \fIRAND_set_rand_engine()\fR was also introduced in version 0.9.7.