xref: /freebsd/secure/lib/libcrypto/man/man3/RAND_load_file.3 (revision d37eb51047221dc3322b34db1038ff3aa533883f)
Automatically generated by Pod::Man 4.14 (Pod::Simple 3.42)

Standard preamble:
========================================================================
..
..
.. 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. \*(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- . 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\} . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\}
Escape single quotes in literal strings from groff's Unicode transform.

If the F register is >0, we'll generate index entries on stderr for
titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
entries marked with X<> in POD. Of course, you'll have to process the
output yourself in some meaningful fashion.

Avoid warning from groff about undefined register 'F'.
.. .nr rF 0 . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF Fear. Run. Save yourself. No user-serviceable parts.
. \" fudge factors for nroff and troff . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] .\} . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} . 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 . \" corrections for vroff . \" for low resolution devices (crt and lpr) \{\ . 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 .\} ========================================================================

Title "RAND_LOAD_FILE 3ossl"
RAND_LOAD_FILE 3ossl "2023-09-19" "3.0.11" "OpenSSL"
For nroff, turn off justification. Always turn off hyphenation; it makes
way too many mistakes in technical documents.
"NAME"
RAND_load_file, RAND_write_file, RAND_file_name - PRNG seed file
"SYNOPSIS"
Header "SYNOPSIS" .Vb 1 #include <openssl/rand.h> \& int RAND_load_file(const char *filename, long max_bytes); \& int RAND_write_file(const char *filename); \& const char *RAND_file_name(char *buf, size_t num); .Ve
"DESCRIPTION"
Header "DESCRIPTION" \fBRAND_load_file() reads a number of bytes from file filename and adds them to the \s-1PRNG.\s0 If max_bytes is nonnegative, up to max_bytes are read; if max_bytes is -1, the complete file is read. Do not load the same file multiple times unless its contents have been updated by RAND_write_file() between reads. Also, note that filename should be adequately protected so that an attacker cannot replace or examine the contents. If filename is not a regular file, then user is considered to be responsible for any side effects, e.g. non-anticipated blocking or capture of controlling terminal.

\fBRAND_write_file() writes a number of random bytes (currently 128) to file filename which can be used to initialize the \s-1PRNG\s0 by calling \fBRAND_load_file() in a later session.

\fBRAND_file_name() generates a default path for the random seed file. buf points to a buffer of size num in which to store the filename.

On all systems, if the environment variable \s-1RANDFILE\s0 is set, its value will be used as the seed filename. Otherwise, the file is called \*(C`.rnd\*(C', found in platform dependent locations:

"On Windows (in order of preference)" 4
Item "On Windows (in order of preference)" .Vb 1 %HOME%, %USERPROFILE%, %SYSTEMROOT%, C:\e .Ve
"On \s-1VMS\s0" 4
Item "On VMS" .Vb 1 SYS$LOGIN: .Ve
"On all other systems" 4
Item "On all other systems" .Vb 1 $HOME .Ve

If $HOME (on non-Windows and non-VMS system) is not set either, or \fBnum is too small for the pathname, an error occurs.

"RETURN VALUES"
Header "RETURN VALUES" \fBRAND_load_file() returns the number of bytes read or -1 on error.

\fBRAND_write_file() returns the number of bytes written, or -1 if the bytes written were generated without appropriate seeding.

\fBRAND_file_name() returns a pointer to buf on success, and \s-1NULL\s0 on error.

"SEE ALSO"
Header "SEE ALSO" \fBRAND_add\|(3), \fBRAND_bytes\|(3), \s-1RAND\s0\|(7)
"COPYRIGHT"
Header "COPYRIGHT" Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the \*(L"License\*(R"). You may not use this file except in compliance with the License. You can obtain a copy in the file \s-1LICENSE\s0 in the source distribution or at <https://www.openssl.org/source/license.html>.