Replaced system SQLite with SQLCipher to support encrypted database

Sources/DataLiteC/libtomcrypt/pk/dsa/dsa_shared_secret.c

@@ -0,0 +1,60 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
+#include "tomcrypt_private.h"
+
+/**
+  @file dsa_shared_secret.c
+  DSA Crypto, Tom St Denis
+*/
+
+#ifdef LTC_MDSA
+
+/**
+  Create a DSA shared secret between two keys
+  @param private_key      The private DSA key (the exponent)
+  @param base             The base of the exponentiation (allows this to be used for both encrypt and decrypt)
+  @param public_key       The public key
+  @param out              [out] Destination of the shared secret
+  @param outlen           [in/out] The max size and resulting size of the shared secret
+  @return CRYPT_OK if successful
+*/
+int dsa_shared_secret(void          *private_key, void *base,
+                      const dsa_key *public_key,
+                      unsigned char *out,         unsigned long *outlen)
+{
+   unsigned long  x;
+   void          *res;
+   int            err;
+
+   LTC_ARGCHK(private_key != NULL);
+   LTC_ARGCHK(public_key  != NULL);
+   LTC_ARGCHK(out         != NULL);
+   LTC_ARGCHK(outlen      != NULL);
+
+   /* make new point */
+   if ((err = ltc_mp_init(&res)) != CRYPT_OK) {
+      return err;
+   }
+
+   if ((err = ltc_mp_exptmod(base, private_key, public_key->p, res)) != CRYPT_OK) {
+      ltc_mp_clear(res);
+      return err;
+   }
+
+   x = (unsigned long)ltc_mp_unsigned_bin_size(res);
+   if (*outlen < x) {
+      *outlen = x;
+      err = CRYPT_BUFFER_OVERFLOW;
+      goto done;
+   }
+   zeromem(out, x);
+   if ((err = ltc_mp_to_unsigned_bin(res, out + (x - ltc_mp_unsigned_bin_size(res))))   != CRYPT_OK)          { goto done; }
+
+   err     = CRYPT_OK;
+   *outlen = x;
+done:
+   ltc_mp_clear(res);
+   return err;
+}
+
+#endif