From 83cb0b0e8cc1e97efdbf53c4e0a14121aef08b42 Mon Sep 17 00:00:00 2001 From: Martin Willi Date: Fri, 28 Apr 2006 09:07:55 +0000 Subject: --- doc/manpage.d/ipsec_prng_final.3.html | 204 ---------------------------------- 1 file changed, 204 deletions(-) delete mode 100644 doc/manpage.d/ipsec_prng_final.3.html (limited to 'doc/manpage.d/ipsec_prng_final.3.html') diff --git a/doc/manpage.d/ipsec_prng_final.3.html b/doc/manpage.d/ipsec_prng_final.3.html deleted file mode 100644 index 27763a2bb..000000000 --- a/doc/manpage.d/ipsec_prng_final.3.html +++ /dev/null @@ -1,204 +0,0 @@ -Content-type: text/html - -Manpage of IPSEC_PRNG - -

IPSEC_PRNG

-Section: C Library Functions (3)
Updated: 1 April 2002
Index -Return to Main Contents

- - - -

NAME

- -ipsec prng_init - initialize IPsec pseudorandom-number generator -
- -ipsec prng_bytes - get bytes from IPsec pseudorandom-number generator -
- -ipsec prng_final - close down IPsec pseudorandom-number generator - -

SYNOPSIS

- -#include <freeswan.h> - -

-void prng_init(struct prng *prng, - -
- -const unsigned char *key, size_t keylen); - -
- -void prng_bytes(struct prng *prng, char *dst, - -
- -size_t dstlen); - -
- -unsigned long prng_count(struct prng *prng); - -
- -void prng_final(struct prng *prng); - - -

DESCRIPTION

- -Prng_init - -initializes a crypto-quality pseudo-random-number generator from a key; -prng_bytes - -obtains pseudo-random bytes from it; -prng_count - -reports the number of bytes extracted from it to date; -prng_final - -closes it down. -It is the user's responsibility to initialize a PRNG before using it, -and not to use it again after it is closed down. -

- -Prng_init - -initializes, -or re-initializes, -the specified -prng - -from the -key, - -whose length is given by -keylen. - -The user must allocate the -struct prng - -pointed to by -prng. - -There is no particular constraint on the length of the key, -although a key longer than 256 bytes is unnecessary because -only the first 256 would be used. -Initialization requires on the order of 3000 integer operations, -independent of key length. -

- -Prng_bytes - -obtains -dstlen - -pseudo-random bytes from the PRNG and puts them in -buf. - -This is quite fast, -on the order of 10 integer operations per byte. -

- -Prng_count - -reports the number of bytes obtained from the PRNG -since it was (last) initialized. -

- -Prng_final - -closes down a PRNG by -zeroing its internal memory, -obliterating all trace of the state used to generate its previous output. -This requires on the order of 250 integer operations. -

- -The -<freeswan.h> - -header file supplies the definition of the -prng - -structure. -Examination of its innards is discouraged, as they may change. -

- -The PRNG algorithm -used by these functions is currently identical to that of RC4(TM). -This algorithm is cryptographically strong, -sufficiently unpredictable that even a hostile observer will -have difficulty determining the next byte of output from past history, -provided it is initialized from a reasonably large key composed of -highly random bytes (see -random(4)). - -The usual run of software pseudo-random-number generators -(e.g. -random(3)) - -are -not - -cryptographically strong. -

- -The well-known attacks against RC4(TM), -e.g. as found in 802.11b's WEP encryption system, -apply only if multiple PRNGs are initialized with closely-related keys -(e.g., using a counter appended to a base key). -If such keys are used, the first few hundred pseudo-random bytes -from each PRNG should be discarded, -to give the PRNGs a chance to randomize their innards properly. -No useful attacks are known if the key is well randomized to begin with. - -

HISTORY

- -Written for the FreeS/WAN project by Henry Spencer. - -

BUGS

- -If an attempt is made to obtain more than 4e9 bytes -between initializations, -the PRNG will continue to work but -prng_count's - -output will stick at -4000000000. - -Fixing this would require a longer integer type and does -not seem worth the trouble, -since you should probably re-initialize before then anyway... -

- -``RC4'' is a trademark of RSA Data Security, Inc. -

- -

Index

NAME: -
SYNOPSIS: -
DESCRIPTION: -
SEE ALSO: -
HISTORY: -
BUGS: -

-This document was created by -man2html, -using the manual pages.
-Time: 21:40:18 GMT, November 11, 2003 - - -- cgit v1.2.3