vendor libsecp256k1 so it doesn't depend on a shared library.

libsecp256k1/src/field_5x52.h

@@ -0,0 +1,62 @@
+/***********************************************************************
+ * Copyright (c) 2013, 2014 Pieter Wuille                              *
+ * Distributed under the MIT software license, see the accompanying    *
+ * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
+ ***********************************************************************/
+
+#ifndef SECP256K1_FIELD_REPR_H
+#define SECP256K1_FIELD_REPR_H
+
+#include <stdint.h>
+
+/** This field implementation represents the value as 5 uint64_t limbs in base
+ *  2^52. */
+typedef struct {
+   /* A field element f represents the sum(i=0..4, f.n[i] << (i*52)) mod p,
+    * where p is the field modulus, 2^256 - 2^32 - 977.
+    *
+    * The individual limbs f.n[i] can exceed 2^52; the field's magnitude roughly
+    * corresponds to how much excess is allowed. The value
+    * sum(i=0..4, f.n[i] << (i*52)) may exceed p, unless the field element is
+    * normalized. */
+    uint64_t n[5];
+    /*
+     * Magnitude m requires:
+     *     n[i] <= 2 * m * (2^52 - 1) for i=0..3
+     *     n[4] <= 2 * m * (2^48 - 1)
+     *
+     * Normalized requires:
+     *     n[i] <= (2^52 - 1) for i=0..3
+     *     sum(i=0..4, n[i] << (i*52)) < p
+     *     (together these imply n[4] <= 2^48 - 1)
+     */
+    SECP256K1_FE_VERIFY_FIELDS
+} secp256k1_fe;
+
+/* Unpacks a constant into a overlapping multi-limbed FE element. */
+#define SECP256K1_FE_CONST_INNER(d7, d6, d5, d4, d3, d2, d1, d0) { \
+    (d0) | (((uint64_t)(d1) & 0xFFFFFUL) << 32), \
+    ((uint64_t)(d1) >> 20) | (((uint64_t)(d2)) << 12) | (((uint64_t)(d3) & 0xFFUL) << 44), \
+    ((uint64_t)(d3) >> 8) | (((uint64_t)(d4) & 0xFFFFFFFUL) << 24), \
+    ((uint64_t)(d4) >> 28) | (((uint64_t)(d5)) << 4) | (((uint64_t)(d6) & 0xFFFFUL) << 36), \
+    ((uint64_t)(d6) >> 16) | (((uint64_t)(d7)) << 16) \
+}
+
+typedef struct {
+    uint64_t n[4];
+} secp256k1_fe_storage;
+
+#define SECP256K1_FE_STORAGE_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {{ \
+    (d0) | (((uint64_t)(d1)) << 32), \
+    (d2) | (((uint64_t)(d3)) << 32), \
+    (d4) | (((uint64_t)(d5)) << 32), \
+    (d6) | (((uint64_t)(d7)) << 32) \
+}}
+
+#define SECP256K1_FE_STORAGE_CONST_GET(d) \
+    (uint32_t)(d.n[3] >> 32), (uint32_t)d.n[3], \
+    (uint32_t)(d.n[2] >> 32), (uint32_t)d.n[2], \
+    (uint32_t)(d.n[1] >> 32), (uint32_t)d.n[1], \
+    (uint32_t)(d.n[0] >> 32), (uint32_t)d.n[0]
+
+#endif /* SECP256K1_FIELD_REPR_H */