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Make RNG parameters mandatory in ECP functions

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Fix trivial faulty calls in ECP test suite and ECP/ECJPAKE self-tests (by
adding a dummy RNG).

Several tests suites are not passing yet, as a couple of library
function do call ecp_mul() with a NULL RNG. The complexity of the fixes
range from "simple refactoring" to "requires API changes", so these will
be addressed in separate commits.

This makes the option MBEDTLS_ECP_NO_INTERNAL_RNG, as well as the whole
"internal RNG" code, obsolete. This will be addressed in a future
commit, after getting the test suites to pass again.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
This commit is contained in:
Manuel Pégourié-Gonnard
2021-06-15 11:29:26 +02:00
parent 7861ecf838
commit aa3ed6f987
4 changed files with 76 additions and 27 deletions
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31
library/ecp.c
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@ -2684,6 +2684,9 @@ int mbedtls_ecp_mul_restartable( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
ECP_VALIDATE_RET( m != NULL );
ECP_VALIDATE_RET( P != NULL );
if( f_rng == NULL )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
#if defined(MBEDTLS_ECP_RESTARTABLE)
/* reset ops count for this call if top-level */
if( rs_ctx != NULL && rs_ctx->depth++ == 0 )
@ -3315,6 +3318,28 @@ cleanup:
#if defined(MBEDTLS_SELF_TEST)
/*
* PRNG for test - !!!INSECURE NEVER USE IN PRODUCTION!!!
*
* This is the linear congruential generator from numerical recipes,
* except we only use the low byte as the output. See
* https://en.wikipedia.org/wiki/Linear_congruential_generator#Parameters_in_common_use
*/
static int self_test_rng( void *ctx, unsigned char *out, size_t len )
{
static uint32_t state = 42;
(void) ctx;
for( size_t i = 0; i < len; i++ )
{
state = state * 1664525u + 1013904223u;
out[i] = (unsigned char) state;
}
return( 0 );
}
/* Adjust the exponent to be a valid private point for the specified curve.
* This is sometimes necessary because we use a single set of exponents
* for all curves but the validity of values depends on the curve. */
@ -3370,7 +3395,7 @@ static int self_test_point( int verbose,
MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( m, 16, exponents[0] ) );
MBEDTLS_MPI_CHK( self_test_adjust_exponent( grp, m ) );
MBEDTLS_MPI_CHK( mbedtls_ecp_mul( grp, R, m, P, NULL, NULL ) );
MBEDTLS_MPI_CHK( mbedtls_ecp_mul( grp, R, m, P, self_test_rng, NULL ) );
for( i = 1; i < n_exponents; i++ )
{
@ -3383,7 +3408,7 @@ static int self_test_point( int verbose,
MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( m, 16, exponents[i] ) );
MBEDTLS_MPI_CHK( self_test_adjust_exponent( grp, m ) );
MBEDTLS_MPI_CHK( mbedtls_ecp_mul( grp, R, m, P, NULL, NULL ) );
MBEDTLS_MPI_CHK( mbedtls_ecp_mul( grp, R, m, P, self_test_rng, NULL ) );
if( add_count != add_c_prev ||
dbl_count != dbl_c_prev ||
@ -3461,7 +3486,7 @@ int mbedtls_ecp_self_test( int verbose )
mbedtls_printf( " ECP SW test #1 (constant op_count, base point G): " );
/* Do a dummy multiplication first to trigger precomputation */
MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &m, 2 ) );
MBEDTLS_MPI_CHK( mbedtls_ecp_mul( &grp, &P, &m, &grp.G, NULL, NULL ) );
MBEDTLS_MPI_CHK( mbedtls_ecp_mul( &grp, &P, &m, &grp.G, self_test_rng, NULL ) );
ret = self_test_point( verbose,
&grp, &R, &m, &grp.G,
sw_exponents,