Commit 6a5b52ef authored by Ulf Möller's avatar Ulf Möller
Browse files

check CRT

parent 6d864b70

CHANGES

+7 −1
Original line number Diff line number Diff line
@@ -4,6 +4,12 @@ 


 Changes between 0.9.6 and 0.9.7  [xx XXX 2000]



  *) Check the result of RSA-CRT (see D. Boneh, R. DeMillo, R. Lipton:

     On the Importance of Eliminating Errors in Cryptographic

	 Computations, J. Cryptology 14 (2001) 2, 101-119,

	 http://theory.stanford.edu/~dabo/papers/faults.ps.gz).

	 [Ulf Moeller]

  

  *) MIPS assembler BIGNUM division bug fix. 

     [Andy Polyakov]

crypto/rsa/rsa_eay.c

+11 −1
Original line number Diff line number Diff line
@@ -453,7 +453,7 @@ err: 
static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)

	{

	const RSA_METHOD *meth;

	BIGNUM r1,m1;

	BIGNUM r1,m1,vrfy;

	int ret=0;

	BN_CTX *ctx;
@@ -461,6 +461,7 @@ static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa) 
	if ((ctx=BN_CTX_new()) == NULL) goto err;

	BN_init(&m1);

	BN_init(&r1);

	BN_init(&vrfy);



	if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)

		{
@@ -541,10 +542,19 @@ static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa) 
	if (!BN_mul(&r1,r0,rsa->q,ctx)) goto err;

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



	if (rsa->e && rsa->n)

		{

		if (!rsa->meth->bn_mod_exp(&vrfy,r0,rsa->e,rsa->n,ctx,NULL)) goto err;

		if (BN_cmp(I, &vrfy) != 0)

			{

			if (!rsa->meth->bn_mod_exp(r0,I,rsa->d,rsa->n,ctx,NULL)) goto err;

			}

		}

	ret=1;

err:

	BN_clear_free(&m1);

	BN_clear_free(&r1);

	BN_clear_free(&vrfy);

	BN_CTX_free(ctx);

	return(ret);

	}