Bignum Mod Raw: pass endianness as a parameter
The external representation before included more than just endianness
(like reading in Mongtomery curve scalars or converting hashes to
numbers in a standard compliant way).
These are higher level concepts and are out of scope for Bignum and for
the modulus structure.
Passing endianness as a parameter is a step towards removing it from the
modulus structure.
Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/library/bignum_mod_raw.c b/library/bignum_mod_raw.c
index 2f49ea2..22e56b7 100644
--- a/library/bignum_mod_raw.c
+++ b/library/bignum_mod_raw.c
@@ -52,11 +52,12 @@
int mbedtls_mpi_mod_raw_read( mbedtls_mpi_uint *X,
const mbedtls_mpi_mod_modulus *m,
const unsigned char *input,
- size_t input_length )
+ size_t input_length,
+ mbedtls_mpi_mod_ext_rep ext_rep )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
- switch( m->ext_rep )
+ switch( ext_rep )
{
case MBEDTLS_MPI_MOD_EXT_REP_LE:
ret = mbedtls_mpi_core_read_le( X, m->limbs,
@@ -87,9 +88,10 @@
int mbedtls_mpi_mod_raw_write( const mbedtls_mpi_uint *A,
const mbedtls_mpi_mod_modulus *m,
unsigned char *output,
- size_t output_length )
+ size_t output_length,
+ mbedtls_mpi_mod_ext_rep ext_rep )
{
- switch( m->ext_rep )
+ switch( ext_rep )
{
case MBEDTLS_MPI_MOD_EXT_REP_LE:
return( mbedtls_mpi_core_write_le( A, m->limbs,
diff --git a/library/bignum_mod_raw.h b/library/bignum_mod_raw.h
index f6c6ebd..d7b6dd1 100644
--- a/library/bignum_mod_raw.h
+++ b/library/bignum_mod_raw.h
@@ -106,6 +106,7 @@
* \param[in] m The address of the modulus related to \p X.
* \param[in] input The input buffer to import from.
* \param input_length The length in bytes of \p input.
+ * \param ext_rep The endianness of the number in the input buffer.
*
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if \p X isn't
@@ -116,7 +117,8 @@
int mbedtls_mpi_mod_raw_read( mbedtls_mpi_uint *X,
const mbedtls_mpi_mod_modulus *m,
const unsigned char *input,
- size_t input_length );
+ size_t input_length,
+ mbedtls_mpi_mod_ext_rep ext_rep );
/** Export A into unsigned binary data.
*
@@ -126,6 +128,7 @@
* \param[in] m The address of the modulus related to \p A.
* \param[out] output The output buffer to export to.
* \param output_length The length in bytes of \p output.
+ * \param ext_rep The endianness in which the number should be written into the output buffer.
*
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL if \p output isn't
@@ -136,7 +139,8 @@
int mbedtls_mpi_mod_raw_write( const mbedtls_mpi_uint *A,
const mbedtls_mpi_mod_modulus *m,
unsigned char *output,
- size_t output_length );
+ size_t output_length,
+ mbedtls_mpi_mod_ext_rep ext_rep );
/* BEGIN MERGE SLOT 1 */
diff --git a/tests/suites/test_suite_bignum_mod_raw.function b/tests/suites/test_suite_bignum_mod_raw.function
index 00ed005..0318978 100644
--- a/tests/suites/test_suite_bignum_mod_raw.function
+++ b/tests/suites/test_suite_bignum_mod_raw.function
@@ -54,17 +54,17 @@
TEST_EQUAL( ret, 0 );
if( iendian == MBEDTLS_MPI_MOD_EXT_REP_INVALID && iret != 0 )
- m.ext_rep = MBEDTLS_MPI_MOD_EXT_REP_INVALID;
+ endian = MBEDTLS_MPI_MOD_EXT_REP_INVALID;
- ret = mbedtls_mpi_mod_raw_read( X, &m, input->x, input->len );
+ ret = mbedtls_mpi_mod_raw_read( X, &m, input->x, input->len, endian );
TEST_EQUAL( ret, iret );
if( iret == 0 )
{
if( iendian == MBEDTLS_MPI_MOD_EXT_REP_INVALID && oret != 0 )
- m.ext_rep = MBEDTLS_MPI_MOD_EXT_REP_INVALID;
+ endian = MBEDTLS_MPI_MOD_EXT_REP_INVALID;
- ret = mbedtls_mpi_mod_raw_write( X, &m, buf, nb );
+ ret = mbedtls_mpi_mod_raw_write( X, &m, buf, nb, endian );
TEST_EQUAL( ret, oret );
}