commit aec1a868fe783a85cd057b78163bd0b1e143f0c6
author Janos Follath <janos.follath@arm.com> Wed Feb 21 11:24:20 2024 +0000
committer Janos Follath <janos.follath@arm.com> Wed Feb 21 11:24:20 2024 +0000
tree 15c073017abed46669a9de698f5ee34ae0df2447
parent 424c2655b98ab00fa35aa4a25fe553d24a17e638

Use mbedtls_ct_condition_t in mpi_core_check_zero

Signed-off-by: Janos Follath <janos.follath@arm.com>

library/bignum_core.c

diff --git a/library/bignum_core.c b/library/bignum_core.c
index dfed60d..f66739d 100644
--- a/library/bignum_core.c
+++ b/library/bignum_core.c
@@ -856,8 +856,8 @@
     return c;
 }
 
-mbedtls_mpi_uint mbedtls_mpi_core_check_zero_ct(const mbedtls_mpi_uint *A,
-                                                size_t limbs)
+mbedtls_ct_condition_t mbedtls_mpi_core_check_zero_ct(const mbedtls_mpi_uint *A,
+                                                      size_t limbs)
 {
     mbedtls_mpi_uint bits = 0;
 
@@ -865,7 +865,7 @@
         bits |= A[i];
     }
 
-    return bits;
+    return mbedtls_ct_bool(bits);
 }
 
 void mbedtls_mpi_core_to_mont_rep(mbedtls_mpi_uint *X,

library/bignum_core.h

diff --git a/library/bignum_core.h b/library/bignum_core.h
index b56be0a..92c8d47 100644
--- a/library/bignum_core.h
+++ b/library/bignum_core.h
@@ -662,11 +662,11 @@
  * \param[in] A   The MPI to test.
  * \param limbs   Number of limbs in \p A.
  *
- * \return        0 if `A == 0`
- *                non-0 (may be any value) if `A != 0`.
+ * \return        MBEDTLS_CT_FALSE if `A == 0`
+ *                MBEDTLS_CT_TRUE  if `A != 0`.
  */
-mbedtls_mpi_uint mbedtls_mpi_core_check_zero_ct(const mbedtls_mpi_uint *A,
-                                                size_t limbs);
+mbedtls_ct_condition_t mbedtls_mpi_core_check_zero_ct(const mbedtls_mpi_uint *A,
+                                                      size_t limbs);
 
 /**
  * \brief          Returns the number of limbs of working memory required for