Add header for mbedtls_mpi_exp_mod_unsafe()
To silence no previous prototype warnings. And this is the proper way to
do it anyway.
Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/library/bignum_internal.h b/library/bignum_internal.h
new file mode 100644
index 0000000..aceaf55
--- /dev/null
+++ b/library/bignum_internal.h
@@ -0,0 +1,50 @@
+/**
+ * \file bignum_internal.h
+ *
+ * \brief Internal-only bignum public-key cryptosystem API.
+ *
+ * This file declares bignum-related functions that are to be used
+ * only from within the Mbed TLS library itself.
+ *
+ */
+/*
+ * Copyright The Mbed TLS Contributors
+ * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+#ifndef MBEDTLS_BIGNUM_INTERNAL_H
+#define MBEDTLS_BIGNUM_INTERNAL_H
+
+/**
+ * \brief Perform a modular exponentiation: X = A^E mod N
+ *
+ * \warning This function is not constant time with respect to \p E (the exponent).
+ *
+ * \param X The destination MPI. This must point to an initialized MPI.
+ * This must not alias E or N.
+ * \param A The base of the exponentiation.
+ * This must point to an initialized MPI.
+ * \param E The exponent MPI. This must point to an initialized MPI.
+ * \param N The base for the modular reduction. This must point to an
+ * initialized MPI.
+ * \param prec_RR A helper MPI depending solely on \p N which can be used to
+ * speed-up multiple modular exponentiations for the same value
+ * of \p N. This may be \c NULL. If it is not \c NULL, it must
+ * point to an initialized MPI. If it hasn't been used after
+ * the call to mbedtls_mpi_init(), this function will compute
+ * the helper value and store it in \p prec_RR for reuse on
+ * subsequent calls to this function. Otherwise, the function
+ * will assume that \p prec_RR holds the helper value set by a
+ * previous call to mbedtls_mpi_exp_mod(), and reuse it.
+ *
+ * \return \c 0 if successful.
+ * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
+ * \return #MBEDTLS_ERR_MPI_BAD_INPUT_DATA if \c N is negative or
+ * even, or if \c E is negative.
+ * \return Another negative error code on different kinds of failures.
+ *
+ */
+int mbedtls_mpi_exp_mod_unsafe(mbedtls_mpi *X, const mbedtls_mpi *A,
+ const mbedtls_mpi *E, const mbedtls_mpi *N,
+ mbedtls_mpi *prec_RR);
+
+#endif /* bignum_internal.h */
diff --git a/tf-psa-crypto/drivers/builtin/src/bignum.c b/tf-psa-crypto/drivers/builtin/src/bignum.c
index b1f9c1b..4244909 100644
--- a/tf-psa-crypto/drivers/builtin/src/bignum.c
+++ b/tf-psa-crypto/drivers/builtin/src/bignum.c
@@ -27,6 +27,7 @@
#include "mbedtls/bignum.h"
#include "bignum_core.h"
+#include "bignum_internal.h"
#include "bn_mul.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"
diff --git a/tf-psa-crypto/drivers/builtin/src/rsa.c b/tf-psa-crypto/drivers/builtin/src/rsa.c
index 3df00c0..16912fd 100644
--- a/tf-psa-crypto/drivers/builtin/src/rsa.c
+++ b/tf-psa-crypto/drivers/builtin/src/rsa.c
@@ -29,6 +29,7 @@
#include "mbedtls/rsa.h"
#include "bignum_core.h"
+#include "bignum_internal.h"
#include "rsa_alt_helpers.h"
#include "rsa_internal.h"
#include "mbedtls/oid.h"
@@ -1227,16 +1228,6 @@
}
/*
- * This function is identical to mbedtls_mpi_exp_mod() the only difference is that this function is
- * not constant time.
- *
- * WARNING! This function is not constant time.
- */
-int mbedtls_mpi_exp_mod_unsafe(mbedtls_mpi *X, const mbedtls_mpi *A,
- const mbedtls_mpi *E, const mbedtls_mpi *N,
- mbedtls_mpi *prec_RR);
-
-/*
* Do an RSA public key operation
*/
int mbedtls_rsa_public(mbedtls_rsa_context *ctx,
diff --git a/tf-psa-crypto/tests/suites/test_suite_bignum.function b/tf-psa-crypto/tests/suites/test_suite_bignum.function
index 1830e5a..3ac4e10 100644
--- a/tf-psa-crypto/tests/suites/test_suite_bignum.function
+++ b/tf-psa-crypto/tests/suites/test_suite_bignum.function
@@ -3,6 +3,7 @@
#include "mbedtls/entropy.h"
#include "constant_time_internal.h"
#include "bignum_core.h"
+#include "bignum_internal.h"
#include "test/constant_flow.h"
#if MBEDTLS_MPI_MAX_BITS > 792