RAND_status() returns to few info.
Hello,
is there a way to ask the random engine about how much randomness
it contains ?
RAND_status() returns 1 if the random pool contains at least
20 bytes (ENTROPY_NEEDED in rand_lcl.h).
That is OK for SSL handshake, but for asymetric key generation
we need a lot of more entropy.
Something like RAND_status1(size_t needed) would be better...
eg:
...
if (RAND_status1(key_length) = 0)
{ /* this part never reached if we have a crypto device... */
RAND_load_file(...); /* load some additional ramdom data */
}
...
Bye
Goetz
--
Goetz Babin-Ebell, TC TrustCenter AG, http://www.trustcenter.de
Sonninstr. 24-28, 20097 Hamburg, Germany
Tel.: +49-(0)40 80 80 26 -0, Fax: +49-(0)40 80 80 26 -126
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Re: RAND_status() returns to few info.
From: Götz Babin-Ebell [EMAIL PROTECTED] babinebell is there a way to ask the random engine about how much randomness babinebell it contains ? babinebell RAND_status() returns 1 if the random pool contains at least babinebell 20 bytes (ENTROPY_NEEDED in rand_lcl.h). babinebell babinebell That is OK for SSL handshake, but for asymetric key generation babinebell we need a lot of more entropy. The 20 bytes minimum is the needed amount of seeding to get secure enough random numbers from the pool. Each time you fetch random bytes, the pool is remixed, thus providing for more random bytes. Unless you find it worrying that we ask of only 20 bytes minimum of seeding, you should be without problems. -- Richard Levitte \ Spannvägen 38, II \ [EMAIL PROTECTED] Redakteur@Stacken \ S-168 35 BROMMA \ T: +46-8-26 52 47 \ SWEDEN \ or +46-733-72 88 11 Procurator Odiosus Ex Infernis-- [EMAIL PROTECTED] Member of the OpenSSL development team: http://www.openssl.org/ Software Engineer, GemPlus: http://www.gemplus.com/ Unsolicited commercial email is subject to an archival fee of $400. See http://www.stacken.kth.se/~levitte/mail/ for more info. __ OpenSSL Project http://www.openssl.org Development Mailing List [EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]
Re: RAND_status() returns to few info.
On Nov 20, 3:03pm, Richard Levitte - VMS Whacker wrote: From: Gotz Babin-Ebell [EMAIL PROTECTED] babinebell is there a way to ask the random engine about how much babinebell randomness it contains ? RAND_status() returns 1 if the babinebell random pool contains at least 20 bytes (ENTROPY_NEEDED babinebell in rand_lcl.h). babinebell babinebell That is OK for SSL handshake, but for asymetric key babinebell generation we need a lot of more entropy. The 20 bytes minimum is the needed amount of seeding to get secure enough random numbers from the pool. Each time you fetch random bytes, the pool is remixed, thus providing for more random bytes. However, it would also be helpful for randomness _sources_ to know how much more randomness is needed. It can be a scarce resource, after all. Unless you find it worrying that we ask of only 20 bytes minimum of seeding, you should be without problems. Being able to check exactly how much has been seeded would also be helpful for applications for which one does _not_ regard 20 bytes as sufficient (e.g., key generation for large, long-term-used keys). -Allen -- Allen Smith [EMAIL PROTECTED] September 11, 2001 A Day That Shall Live In Infamy II They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety. - Benjamin Franklin __ OpenSSL Project http://www.openssl.org Development Mailing List [EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]
Re: RAND_status() returns to few info.
From: Allen Smith [EMAIL PROTECTED] easmith The 20 bytes minimum is the needed amount of seeding to get secure easmith enough random numbers from the pool. Each time you fetch random easmith bytes, the pool is remixed, thus providing for more random bytes. easmith easmith However, it would also be helpful for randomness _sources_ to easmith know how much more randomness is needed. It can be a scarce easmith resource, after all. Uhmm, an exactly how should OpenSSL tell the sources how much more seeding it needs, except for actually reading that many bytes? easmith Unless you find it worrying that we ask of only 20 bytes minimum of easmith seeding, you should be without problems. easmith easmith Being able to check exactly how much has been seeded would also be easmith helpful for applications for which one does _not_ regard 20 bytes as easmith sufficient (e.g., key generation for large, long-term-used keys). That's what the Unless ... was about, I guess :-). -- Richard Levitte \ Spannvägen 38, II \ [EMAIL PROTECTED] Redakteur@Stacken \ S-168 35 BROMMA \ T: +46-8-26 52 47 \ SWEDEN \ or +46-733-72 88 11 Procurator Odiosus Ex Infernis-- [EMAIL PROTECTED] Member of the OpenSSL development team: http://www.openssl.org/ Software Engineer, GemPlus: http://www.gemplus.com/ Unsolicited commercial email is subject to an archival fee of $400. See http://www.stacken.kth.se/~levitte/mail/ for more info. __ OpenSSL Project http://www.openssl.org Development Mailing List [EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]
