Adapt rsa_complete to deal with RSA_NO_CRT option

This commit is contained in:
Hanno Becker 2017-08-23 07:43:27 +01:00
parent 131134fa1a
commit 23344b5fcc

View file

@ -612,6 +612,7 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx,
* to our current RSA implementaiton.
*/
#if !defined(MBEDTLS_RSA_NO_CRT)
if( is_priv )
{
ret = mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D,
@ -619,6 +620,7 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx,
if( ret != 0 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
}
#endif /* MBEDTLS_RSA_NO_CRT */
/*
* Step 3: Double check
@ -647,31 +649,89 @@ int mbedtls_rsa_complete( mbedtls_rsa_context *ctx,
int mbedtls_rsa_check_crt( mbedtls_rsa_context *ctx, mbedtls_mpi *DP,
mbedtls_mpi *DQ, mbedtls_mpi *QP )
{
/* Check if key is private or public */
const int opt_present =
mbedtls_mpi_cmp_int( &ctx->DP, 0 ) != 0 &&
mbedtls_mpi_cmp_int( &ctx->DQ, 0 ) != 0 &&
mbedtls_mpi_cmp_int( &ctx->QP, 0 ) != 0;
int ret = 0;
if( !opt_present )
/* Check if key is private or public */
const int is_priv =
mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 &&
mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 &&
mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 &&
mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 &&
mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0;
if( !is_priv )
{
/* Checking optional parameters only makes sense for private keys. */
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
}
/* Alternative implementations not having DP, DQ, QP as part of
* the RSA context structure could perform the following checks instead:
* (1) Check that DP - P == 0 mod P - 1
* (2) Check that DQ - Q == 0 mod Q - 1
* (3) Check that QP * P - 1 == 0 mod P
*/
#if !defined(MBEDTLS_RSA_NO_CRT)
if( ( DP != NULL && mbedtls_mpi_cmp_mpi( DP, &ctx->DP ) != 0 ) ||
( DQ != NULL && mbedtls_mpi_cmp_mpi( DQ, &ctx->DQ ) != 0 ) ||
( QP != NULL && mbedtls_mpi_cmp_mpi( QP, &ctx->QP ) != 0 ) )
{
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
}
#else /* MBEDTLS_RSA_NO_CRT */
/*
* Check that DP, DQ and QP are in accordance with core parameters.
* (1) Check that DP - P == 0 mod P - 1
* (2) Check that DQ - Q == 0 mod Q - 1
* (3) Check that QP * P - 1 == 0 mod P
* Alternative implementation also not using DP, DQ and QP
* should be able to reuse this codepath.
*/
/* Check (1) */
if( DP != NULL )
{
/* Temporarily replace P by P-1 and compute DP - D mod P-1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &ctx->P, &ctx->P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( DP, DP, &ctx->D ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( DP, DP, &ctx->P ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &ctx->P, &ctx->P, 1 ) );
if( mbedtls_mpi_cmp_int( DP, 0 ) != 0 )
{
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
}
}
/* Check (1) */
if( DQ != NULL )
{
/* Temporarily replace Q by Q-1 and compute DQ - D mod Q-1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &ctx->Q, &ctx->Q, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( DQ, DQ, &ctx->D ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( DQ, DQ, &ctx->Q ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &ctx->Q, &ctx->Q, 1 ) );
if( mbedtls_mpi_cmp_int( DQ, 0 ) != 0 )
{
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
}
}
/* Check (3) */
if( QP != NULL )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( QP, QP, &ctx->Q ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( QP, QP, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( QP, QP, &ctx->P ) );
if( mbedtls_mpi_cmp_int( QP, 0 ) != 0 )
{
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
}
}
cleanup:
#endif
if( ret != 0 )
return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret );
return( 0 );
}