Make RNG parameters mandatory in ECP functions
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>
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 49e85d9..f203a7b 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -911,15 +911,8 @@
* \note To prevent timing attacks, this function
* executes the exact same sequence of base-field
* operations for any valid \p m. It avoids any if-branch or
- * array index depending on the value of \p m.
- *
- * \note If \p f_rng is not NULL, it is used to randomize
- * intermediate results to prevent potential timing attacks
- * targeting these results. We recommend always providing
- * a non-NULL \p f_rng. The overhead is negligible.
- * Note: unless #MBEDTLS_ECP_NO_INTERNAL_RNG is defined, when
- * \p f_rng is NULL, an internal RNG (seeded from the value
- * of \p m) will be used instead.
+ * array index depending on the value of \p m. If also uses
+ * \p f_rng to randomize some intermediate results.
*
* \param grp The ECP group to use.
* This must be initialized and have group parameters
@@ -928,9 +921,9 @@
* This must be initialized.
* \param m The integer by which to multiply. This must be initialized.
* \param P The point to multiply. This must be initialized.
- * \param f_rng The RNG function. This may be \c NULL if randomization
- * of intermediate results isn't desired (discouraged).
- * \param p_rng The RNG context to be passed to \p p_rng.
+ * \param f_rng The RNG function. This must not be \c NULL.
+ * \param p_rng The RNG context to be passed to \p f_rng. This may be \c
+ * NULL if \p f_rng doesn't need a context.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_ECP_INVALID_KEY if \p m is not a valid private
@@ -959,9 +952,9 @@
* This must be initialized.
* \param m The integer by which to multiply. This must be initialized.
* \param P The point to multiply. This must be initialized.
- * \param f_rng The RNG function. This may be \c NULL if randomization
- * of intermediate results isn't desired (discouraged).
- * \param p_rng The RNG context to be passed to \p p_rng.
+ * \param f_rng The RNG function. This must not be \c NULL.
+ * \param p_rng The RNG context to be passed to \p f_rng. This may be \c
+ * NULL if \p f_rng doesn't need a context.
* \param rs_ctx The restart context (NULL disables restart).
*
* \return \c 0 on success.