1 files changed, 93 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_is_square.c b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_is_square.c
new file mode 100644
index 0000000..69e77a2
--- /dev/null
+++ b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_is_square.c
@@ -0,0 +1,93 @@
+#include "tommath_private.h"
+#ifdef BN_MP_IS_SQUARE_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
+
+/* Check if remainders are possible squares - fast exclude non-squares */
+static const char rem_128[128] = {
+   0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1,
+   0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1,
+   1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1,
+   1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1,
+   0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1,
+   1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1,
+   1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1,
+   1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1
+};
+
+static const char rem_105[105] = {
+   0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,
+   0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1,
+   0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1,
+   1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1,
+   0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1,
+   1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1,
+   1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1
+};
+
+/* Store non-zero to ret if arg is square, and zero if not */
+mp_err mp_is_square(const mp_int *arg, mp_bool *ret)
+{
+   mp_err        err;
+   mp_digit      c;
+   mp_int        t;
+   unsigned long r;
+
+   /* Default to Non-square :) */
+   *ret = MP_NO;
+
+   if (arg->sign == MP_NEG) {
+      return MP_VAL;
+   }
+
+   if (MP_IS_ZERO(arg)) {
+      return MP_OKAY;
+   }
+
+   /* First check mod 128 (suppose that MP_DIGIT_BIT is at least 7) */
+   if (rem_128[127u & arg->dp[0]] == (char)1) {
+      return MP_OKAY;
+   }
+
+   /* Next check mod 105 (3*5*7) */
+   if ((err = mp_mod_d(arg, 105uL, &c)) != MP_OKAY) {
+      return err;
+   }
+   if (rem_105[c] == (char)1) {
+      return MP_OKAY;
+   }
+
+
+   if ((err = mp_init_u32(&t, 11u*13u*17u*19u*23u*29u*31u)) != MP_OKAY) {
+      return err;
+   }
+   if ((err = mp_mod(arg, &t, &t)) != MP_OKAY) {
+      goto LBL_ERR;
+   }
+   r = mp_get_u32(&t);
+   /* Check for other prime modules, note it's not an ERROR but we must
+    * free "t" so the easiest way is to goto LBL_ERR.  We know that err
+    * is already equal to MP_OKAY from the mp_mod call
+    */
+   if (((1uL<<(r%11uL)) & 0x5C4uL) != 0uL)         goto LBL_ERR;
+   if (((1uL<<(r%13uL)) & 0x9E4uL) != 0uL)         goto LBL_ERR;
+   if (((1uL<<(r%17uL)) & 0x5CE8uL) != 0uL)        goto LBL_ERR;
+   if (((1uL<<(r%19uL)) & 0x4F50CuL) != 0uL)       goto LBL_ERR;
+   if (((1uL<<(r%23uL)) & 0x7ACCA0uL) != 0uL)      goto LBL_ERR;
+   if (((1uL<<(r%29uL)) & 0xC2EDD0CuL) != 0uL)     goto LBL_ERR;
+   if (((1uL<<(r%31uL)) & 0x6DE2B848uL) != 0uL)    goto LBL_ERR;
+
+   /* Final check - is sqr(sqrt(arg)) == arg ? */
+   if ((err = mp_sqrt(arg, &t)) != MP_OKAY) {
+      goto LBL_ERR;
+   }
+   if ((err = mp_sqr(&t, &t)) != MP_OKAY) {
+      goto LBL_ERR;
+   }
+
+   *ret = (mp_cmp_mag(&t, arg) == MP_EQ) ? MP_YES : MP_NO;
+LBL_ERR:
+   mp_clear(&t);
+   return err;
+}
+#endif