Commit a96022b3 authored by Matt Caswell's avatar Matt Caswell
Browse files

Clarify BN_mod_exp docs 



Specifically this is not supported with an even modulus and
BN_FLG_CONSTTIME.

Fixes #5082

Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6138)

(cherry picked from commit 966b3df1)
parent b9f0d183

doc/crypto/BN_add.pod

+3 −1
Original line number Diff line number Diff line
@@ -91,7 +91,9 @@ BN_exp() raises I<a> to the I<p>-th power and places the result in I<r> 
BN_mul().



BN_mod_exp() computes I<a> to the I<p>-th power modulo I<m> (C<r=a^p %

m>). This function uses less time and space than BN_exp().

m>). This function uses less time and space than BN_exp(). Do not call this

function when B<m> is even and any of the parameters have the

B<BN_FLG_CONSTTIME> flag set.



BN_gcd() computes the greatest common divisor of I<a> and I<b> and

places the result in I<r>. I<r> may be the same B<BIGNUM> as I<a> or