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-rw-r--r--third_party/heimdal/lib/hcrypto/libtommath/bn_mp_reduce_2k_setup.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_reduce_2k_setup.c b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_reduce_2k_setup.c
new file mode 100644
index 0000000..2eaf7ad
--- /dev/null
+++ b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_reduce_2k_setup.c
@@ -0,0 +1,32 @@
+#include "tommath_private.h"
+#ifdef BN_MP_REDUCE_2K_SETUP_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
+
+/* determines the setup value */
+mp_err mp_reduce_2k_setup(const mp_int *a, mp_digit *d)
+{
+ mp_err err;
+ mp_int tmp;
+ int p;
+
+ if ((err = mp_init(&tmp)) != MP_OKAY) {
+ return err;
+ }
+
+ p = mp_count_bits(a);
+ if ((err = mp_2expt(&tmp, p)) != MP_OKAY) {
+ mp_clear(&tmp);
+ return err;
+ }
+
+ if ((err = s_mp_sub(&tmp, a, &tmp)) != MP_OKAY) {
+ mp_clear(&tmp);
+ return err;
+ }
+
+ *d = tmp.dp[0];
+ mp_clear(&tmp);
+ return MP_OKAY;
+}
+#endif