Add comments for some forbidden aliasing in bignum
@@ -758,11 +758,11 @@ int mbedtls_mpi_mul_int( mbedtls_mpi *X, const mbedtls_mpi *A,
*
* \param Q The destination MPI for the quotient.
* This may be \c NULL if the value of the
- * quotient is not needed.
+ * quotient is not needed. This must not alias A or B.
* \param R The destination MPI for the remainder value.
* This may be \c NULL if the value of the
- * remainder is not needed.
- * \param A The dividend. This must point to an initialized MPi.
+ * remainder is not needed. This must not alias A or B.
+ * \param A The dividend. This must point to an initialized MPI.
* \param B The divisor. This must point to an initialized MPI.
*
* \return \c 0 if successful.
@@ -779,10 +779,10 @@ int mbedtls_mpi_div_mpi( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A,
*
* \param Q The destination MPI for the quotient.
* This may be \c NULL if the value of the
- * quotient is not needed.
+ * quotient is not needed. This must not alias A.
* \param R The destination MPI for the remainder value.
* This may be \c NULL if the value of the
- * remainder is not needed.
+ * remainder is not needed. This must not alias A.
* \param A The dividend. This must point to an initialized MPi.
* \param b The divisor.
*
@@ -837,6 +837,7 @@ int mbedtls_mpi_mod_int( mbedtls_mpi_uint *r, const mbedtls_mpi *A,
* \brief Perform a sliding-window exponentiation: X = A^E mod N
*
* \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.
