Commit abd4c915 authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
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Fix for RSA private key encryption if p < q. This took ***ages*** to track down.

parent 47c389e7

CHANGES

+5 −0
Original line number Original line Diff line number Diff line
@@ -5,6 +5,11 @@ 




 Changes between 0.9.1c and 0.9.2

 Changes between 0.9.1c and 0.9.2





  *) Fix to RSA private encryption routines: if p < q then it would

     occasionally produce an invalid result. This will only happen with

     externally generated keys because OpenSSL (and SSLeay) ensure p > q.

     [Steve Henson]



  *) Be less restrictive and allow also `perl util/perlpath.pl

  *) Be less restrictive and allow also `perl util/perlpath.pl

     /path/to/bin/perl' in addition to `perl util/perlpath.pl /path/to/bin',

     /path/to/bin/perl' in addition to `perl util/perlpath.pl /path/to/bin',

     because this way one can also use an interpreter named `perl5' (which is

     because this way one can also use an interpreter named `perl5' (which is

crypto/rsa/rsa_eay.c

+9 −0
Original line number Original line Diff line number Diff line
@@ -473,6 +473,15 @@ RSA *rsa; 




	if (!BN_mul(&r1,r0,rsa->iqmp,ctx)) goto err;

	if (!BN_mul(&r1,r0,rsa->iqmp,ctx)) goto err;

	if (!BN_mod(r0,&r1,rsa->p,ctx)) goto err;

	if (!BN_mod(r0,&r1,rsa->p,ctx)) goto err;

	/* If p < q it is occasionally possible for the correction of

         * adding 'p' if r0 is negative above to leave the result still

	 * negative. This can break the private key operations: the following

	 * second correction should *always* correct this rare occurrence.

	 * This will *never* happen with OpenSSL generated keys because

         * they ensure p > q [steve]

         */

	if (r0->neg)

		if (!BN_add(r0,r0,rsa->p)) goto err;

	if (!BN_mul(&r1,r0,rsa->q,ctx)) goto err;

	if (!BN_mul(&r1,r0,rsa->q,ctx)) goto err;

	if (!BN_add(r0,&r1,&m1)) goto err;

	if (!BN_add(r0,&r1,&m1)) goto err;