Add public function generating private keys
This will be useful for restartable ECDH and ECDSA. Currently they call
mbedtls_ecp_gen_keypair(); one could make that one restartable, but that means
adding its own sub-context, while ECDH and ECDSA (will) have their own
contexts already, so switching to this saves one extra context.
diff --git a/library/ecp.c b/library/ecp.c
index f520b9c..dfc5dd8 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -2495,15 +2495,14 @@
}
/*
- * Generate a keypair with configurable base point
+ * Generate a private key
*/
-int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp,
- const mbedtls_ecp_point *G,
- mbedtls_mpi *d, mbedtls_ecp_point *Q,
+int mbedtls_ecp_gen_privkey( const mbedtls_ecp_group *grp,
+ mbedtls_mpi *d,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
- int ret;
+ int ret = MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
size_t n_size = ( grp->nbits + 7 ) / 8;
#if defined(ECP_MONTGOMERY)
@@ -2528,8 +2527,8 @@
MBEDTLS_MPI_CHK( mbedtls_mpi_set_bit( d, 1, 0 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_set_bit( d, 2, 0 ) );
}
- else
#endif /* ECP_MONTGOMERY */
+
#if defined(ECP_SHORTWEIERSTRASS)
if( ecp_get_type( grp ) == ECP_TYPE_SHORT_WEIERSTRASS )
{
@@ -2565,15 +2564,28 @@
while( mbedtls_mpi_cmp_int( d, 1 ) < 0 ||
mbedtls_mpi_cmp_mpi( d, &grp->N ) >= 0 );
}
- else
#endif /* ECP_SHORTWEIERSTRASS */
- return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
cleanup:
- if( ret != 0 )
- return( ret );
+ return( ret );
+}
- return( mbedtls_ecp_mul( grp, Q, d, G, f_rng, p_rng ) );
+/*
+ * Generate a keypair with configurable base point
+ */
+int mbedtls_ecp_gen_keypair_base( mbedtls_ecp_group *grp,
+ const mbedtls_ecp_point *G,
+ mbedtls_mpi *d, mbedtls_ecp_point *Q,
+ int (*f_rng)(void *, unsigned char *, size_t),
+ void *p_rng )
+{
+ int ret;
+
+ MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, d, f_rng, p_rng ) );
+ MBEDTLS_MPI_CHK( mbedtls_ecp_mul( grp, Q, d, G, f_rng, p_rng ) );
+
+cleanup:
+ return( ret );
}
/*