bignum_core: Aligned `xxx_core_shift_l` to `xxx_core_shift_r`
This patch modifies the left-shift implementation to closely
align in interface and behaviour to the existing right-shift
method.
Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
diff --git a/library/bignum_core.h b/library/bignum_core.h
index 25e7e1a..2b11cca 100644
--- a/library/bignum_core.h
+++ b/library/bignum_core.h
@@ -278,7 +278,7 @@
unsigned char *output,
size_t output_length);
-/** \brief Shift an MPI right in place by a number of bits.
+/** \brief Shift an MPI in-place right by a number of bits.
*
* Shifting by more bits than there are bit positions
* in \p X is valid and results in setting \p X to 0.
@@ -294,16 +294,19 @@
size_t count);
/**
- * \brief Perform a left-shift on an MPI: X <<= count
+ * \brief Shift an MPI in-place left by a number of bits.
*
- * \param X The MPI to shift. This must point to an initialized MPI.
- * \param count The number of bits to shift by.
+ * Shifting by more bits than there are bit positions
+ * in \p X is valid and results in setting \p X to 0.
*
- * \return \c 0 if successful.
- * \return #MBEDTLS_ERR_MPI_ALLOC_FAILED if a memory allocation failed.
- * \return Another negative error code on different kinds of failure.
+ * This function's execution time depends on the value
+ * of \p count (and of course \p limbs).
+ * \param[in,out] X The number to shift.
+ * \param limbs The number of limbs of \p X. This must be at least 1.
+ * \param count The number of bits to shift by.
*/
-int mbedtls_mpi_shift_l( mbedtls_mpi *X, size_t count );
+void mbedtls_mpi_core_shift_l(mbedtls_mpi_uint *X, size_t limbs,
+ size_t count);
/**
* \brief Add two fixed-size large unsigned integers, returning the carry.