Introduce secp256k1_scalar_t for future constant-time mod order operations

2014-10-28 04:08:15 -07:00
parent b2bfdabdeb
commit a9f5c8b875
14 changed files with 319 additions and 149 deletions
--- a/src/num_gmp_impl.h
+++ b/src/num_gmp_impl.h
@@ -362,4 +362,12 @@ void static secp256k1_num_negate(secp256k1_num_t *r) {
    r->neg ^= 1;
 }

+int static secp256k1_num_get_bits(const secp256k1_num_t *a, int offset, int count) {
+    int ret = 0;
+    for (int i = 0; i < count; i++) {
+        ret |= ((a->data[(offset + i) / GMP_NUMB_BITS] >> ((offset + i) % GMP_NUMB_BITS)) & 1) << i;
+    }
+    return ret;
+}
+
 #endif