Replaced system SQLite with SQLCipher to support encrypted database

Sources/DataLiteC/libtomcrypt/misc/copy_or_zeromem.c

@@ -0,0 +1,51 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
+#include "tomcrypt_private.h"
+
+/**
+   @file copy_or_zeromem.c
+   Either copy or zero a block of memory in constant time, Steffen Jaeckel
+*/
+
+/**
+   Either copy or zero a block of memory in constant time
+   @param src    The source where to read from
+   @param dest   The destination where to write to
+   @param len    The length of the area to process (octets)
+   @param coz    Copy (on 0) Or Zero (> 0)
+*/
+void copy_or_zeromem(const unsigned char* src, unsigned char* dest, unsigned long len, int coz)
+{
+   unsigned long y;
+#ifdef LTC_FAST
+   unsigned long z;
+   LTC_FAST_TYPE fastMask = ~(LTC_FAST_TYPE)0; /* initialize fastMask at all ones */
+#endif
+   unsigned char mask = 0xff; /* initialize mask at all ones */
+
+   LTC_ARGCHKVD(src  != NULL);
+   LTC_ARGCHKVD(dest != NULL);
+
+   if (coz != 0) coz = 1;
+   y = 0;
+   mask *= 1 - coz; /* mask = ( coz ? 0 : 0xff ) */
+#ifdef LTC_FAST
+   fastMask *= 1 - coz;
+   if (len & ~15) {
+      for (; y < (len & ~15); y += 16) {
+        for (z = 0; z < 16; z += sizeof(LTC_FAST_TYPE)) {
+          *(LTC_FAST_TYPE_PTR_CAST(&dest[y+z])) = *(LTC_FAST_TYPE_PTR_CAST(&src[y+z])) & fastMask;
+        }
+      }
+   }
+#endif
+   for (; y < len; y++) {
+      dest[y] = src[y] & mask;
+   }
+#ifdef LTC_CLEAN_STACK
+#ifdef LTC_FAST
+   fastMask = 0;
+#endif
+   mask = 0;
+#endif
+}