From 321df6fb80d55ca86500c6346fc3cdffeb39fda2 Mon Sep 17 00:00:00 2001
From: Paul Bakker
Date: Thu, 27 Sep 2012 13:21:34 +0000
Subject: [PATCH] - Expanded rsa_check_privkey() to check DP, DQ and QP as
well
---
library/rsa.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/library/rsa.c b/library/rsa.c
index b9d6bec0c..2dcb130cb 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -161,7 +161,7 @@ int rsa_check_pubkey( const rsa_context *ctx )
int rsa_check_privkey( const rsa_context *ctx )
{
int ret;
- mpi PQ, DE, P1, Q1, H, I, G, G2, L1, L2;
+ mpi PQ, DE, P1, Q1, H, I, G, G2, L1, L2, DP, DQ, QP;
if( ( ret = rsa_check_pubkey( ctx ) ) != 0 )
return( ret );
@@ -171,7 +171,8 @@ int rsa_check_privkey( const rsa_context *ctx )
mpi_init( &PQ ); mpi_init( &DE ); mpi_init( &P1 ); mpi_init( &Q1 );
mpi_init( &H ); mpi_init( &I ); mpi_init( &G ); mpi_init( &G2 );
- mpi_init( &L1 ); mpi_init( &L2 );
+ mpi_init( &L1 ); mpi_init( &L2 ); mpi_init( &DP ); mpi_init( &DQ );
+ mpi_init( &QP );
MPI_CHK( mpi_mul_mpi( &PQ, &ctx->P, &ctx->Q ) );
MPI_CHK( mpi_mul_mpi( &DE, &ctx->D, &ctx->E ) );
@@ -184,23 +185,28 @@ int rsa_check_privkey( const rsa_context *ctx )
MPI_CHK( mpi_div_mpi( &L1, &L2, &H, &G2 ) );
MPI_CHK( mpi_mod_mpi( &I, &DE, &L1 ) );
+ MPI_CHK( mpi_mod_mpi( &DP, &ctx->D, &P1 ) );
+ MPI_CHK( mpi_mod_mpi( &DQ, &ctx->D, &Q1 ) );
+ MPI_CHK( mpi_inv_mod( &QP, &ctx->Q, &ctx->P ) );
/*
* Check for a valid PKCS1v2 private key
*/
if( mpi_cmp_mpi( &PQ, &ctx->N ) != 0 ||
+ mpi_cmp_mpi( &DP, &ctx->DP ) != 0 ||
+ mpi_cmp_mpi( &DQ, &ctx->DQ ) != 0 ||
+ mpi_cmp_mpi( &QP, &ctx->QP ) != 0 ||
mpi_cmp_int( &L2, 0 ) != 0 ||
mpi_cmp_int( &I, 1 ) != 0 ||
mpi_cmp_int( &G, 1 ) != 0 )
{
ret = POLARSSL_ERR_RSA_KEY_CHECK_FAILED;
}
-
cleanup:
-
mpi_free( &PQ ); mpi_free( &DE ); mpi_free( &P1 ); mpi_free( &Q1 );
mpi_free( &H ); mpi_free( &I ); mpi_free( &G ); mpi_free( &G2 );
- mpi_free( &L1 ); mpi_free( &L2 );
+ mpi_free( &L1 ); mpi_free( &L2 ); mpi_free( &DP ); mpi_free( &DQ );
+ mpi_free( &QP );
if( ret == POLARSSL_ERR_RSA_KEY_CHECK_FAILED )
return( ret );