Rm ecp_add() and add ecp_muladd()
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 901c23e..224e135 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -482,26 +482,19 @@
unsigned char *buf, size_t blen );
/**
- * \brief Addition: R = P + Q
- *
- * \param grp ECP group
- * \param R Destination point
- * \param P Left-hand point
- * \param Q Right-hand point
- *
- * \return 0 if successful,
- * MBEDTLS_ERR_MPI_MALLOC_FAILED if memory allocation failed
- *
- * \note This function does not support Montgomery curves, such as
- * Curve25519.
- */
-int mbedtls_ecp_add( const mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
- const mbedtls_ecp_point *P, const mbedtls_ecp_point *Q );
-
-/**
* \brief Multiplication by an integer: R = m * P
* (Not thread-safe to use same group in multiple threads)
*
+ * \note In order to prevent timing attacks, this function
+ * executes the exact same sequence of (base field)
+ * operations for any valid m. It avoids any if-branch or
+ * array index depending on the value of m.
+ *
+ * \note If f_rng is not NULL, it is used to randomize intermediate
+ * results in order to prevent potential timing attacks
+ * targeting these results. It is recommended to always
+ * provide a non-NULL f_rng (the overhead is negligible).
+ *
* \param grp ECP group
* \param R Destination point
* \param m Integer by which to multiply
@@ -513,22 +506,36 @@
* MBEDTLS_ERR_ECP_INVALID_KEY if m is not a valid privkey
* or P is not a valid pubkey,
* MBEDTLS_ERR_MPI_MALLOC_FAILED if memory allocation failed
- *
- * \note In order to prevent timing attacks, this function
- * executes the exact same sequence of (base field)
- * operations for any valid m. It avoids any if-branch or
- * array index depending on the value of m.
- *
- * \note If f_rng is not NULL, it is used to randomize intermediate
- * results in order to prevent potential timing attacks
- * targeting these results. It is recommended to always
- * provide a non-NULL f_rng (the overhead is negligible).
*/
int mbedtls_ecp_mul( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
const mbedtls_mpi *m, const mbedtls_ecp_point *P,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
/**
+ * \brief Multiplication and addition of two points by integers:
+ * R = m * P + n * Q
+ * (Not thread-safe to use same group in multiple threads)
+ *
+ * \note In contrast to ecp_mul(), this function does not guarantee
+ * a constant execution flow and timing.
+ *
+ * \param grp ECP group
+ * \param R Destination point
+ * \param m Integer by which to multiply P
+ * \param P Point to multiply by m
+ * \param n Integer by which to multiply Q
+ * \param Q Point to be multiplied by n
+ *
+ * \return 0 if successful,
+ * MBEDTLS_ERR_ECP_INVALID_KEY if m or n is not a valid privkey
+ * or P or Q is not a valid pubkey,
+ * MBEDTLS_ERR_MPI_MALLOC_FAILED if memory allocation failed
+ */
+int mbedtls_ecp_muladd( mbedtls_ecp_group *grp, mbedtls_ecp_point *R,
+ const mbedtls_mpi *m, const mbedtls_ecp_point *P,
+ const mbedtls_mpi *n, const mbedtls_ecp_point *Q );
+
+/**
* \brief Check that a point is a valid public key on this curve
*
* \param grp Curve/group the point should belong to