Replaced system SQLite with SQLCipher to support encrypted database

Sources/DataLiteC/libtomcrypt/pk/ecc/ltc_ecc_verify_key.c

@@ -0,0 +1,59 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
+
+#include "tomcrypt_private.h"
+
+/* origin of this code - OLPC */
+
+#ifdef LTC_MECC
+
+/**
+  Verify a key according to ANSI spec
+  @param key     The key to validate
+  @return CRYPT_OK if successful
+*/
+
+int ltc_ecc_verify_key(const ecc_key *key)
+{
+   int err, inf;
+   ecc_point *point;
+   void *prime = key->dp.prime;
+   void *order = key->dp.order;
+   void *a     = key->dp.A;
+
+   /* Test 1: Are the x and y points of the public key in the field? */
+   if (ltc_mp.compare_d(key->pubkey.z, 1) == LTC_MP_EQ) {
+      if ((ltc_mp.compare(key->pubkey.x, prime) != LTC_MP_LT) ||
+          (ltc_mp.compare(key->pubkey.y, prime) != LTC_MP_LT) ||
+          (ltc_mp.compare_d(key->pubkey.x, 0) == LTC_MP_LT) ||
+          (ltc_mp.compare_d(key->pubkey.y, 0) == LTC_MP_LT) ||
+          (ltc_mp_iszero(key->pubkey.x) && ltc_mp_iszero(key->pubkey.y))
+         )
+      {
+         err = CRYPT_INVALID_PACKET;
+         goto done2;
+      }
+   }
+
+   /* Test 2: is the public key on the curve? */
+   if ((err = ltc_ecc_is_point(&key->dp, key->pubkey.x, key->pubkey.y)) != CRYPT_OK)      { goto done2; }
+
+   /* Test 3: does nG = O? (n = order, O = point at infinity, G = public key) */
+   point = ltc_ecc_new_point();
+   if ((err = ltc_ecc_mulmod(order, &(key->pubkey), point, a, prime, 1)) != CRYPT_OK)     { goto done1; }
+
+   err = ltc_ecc_is_point_at_infinity(point, prime, &inf);
+   if (err != CRYPT_OK || inf) {
+      err = CRYPT_ERROR;
+   }
+   else {
+      err = CRYPT_OK;
+   }
+
+done1:
+   ltc_ecc_del_point(point);
+done2:
+   return err;
+}
+
+#endif