Support loading tfcrypt_defs.h variables from file.

[tfcrypt.git] / tfc_conf.c

diff --git a/tfc_conf.c b/tfc_conf.c
new file mode 100644 (file)
index 0000000..bd2b112
--- /dev/null
+++ b/tfc_conf.c
@@ -0,0 +1,102 @@
+/*
+ * tfcrypt -- high security Threefish encryption tool.
+ *
+ * tfcrypt is copyrighted:
+ * Copyright (C) 2012-2018 Andrey Rys. All rights reserved.
+ *
+ * tfcrypt is licensed to you under the terms of std. MIT/X11 license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "tfcrypt.h"
+
+void read_defaults(const char *path, tfc_yesno noerr)
+{
+       static char ln[4096];
+       char *s, *d, *t, *stoi;
+       FILE *f;
+       tfc_yesno valid = NO;
+
+       f = fopen(path, "r");
+       if (!f) {
+               if (noerr == YES) return;
+               xerror(NO, NO, YES, "%s", path);
+       }
+
+       while (1) {
+               memset(ln, 0, sizeof(ln));
+               if (xfgets(ln, sizeof(ln), f) != YES) break;
+
+               if (valid == NO) {
+                       if (!strcmp(ln, "# tfcrypt.defs")) valid = YES;
+                       continue;
+               }
+
+               if (str_empty(ln) || ln[0] == '#') continue;
+
+               s = ln;
+               d = strchr(s, '=');
+               if (!d) continue;
+               *d = 0; d++;
+
+               /* yay! GOTO hell! You'll "like" it! */
+_spc1:         t = strchr(s, ' ');
+               if (!t) goto _spc2;
+               *t = 0; goto _spc1;
+_spc2:         t = strchr(d, ' ');
+               if (!t) goto _nspc;
+               *t = 0; d = t+1; goto _spc2;
+_nspc:
+               if (!strcmp(s, "nr_turns")) {
+                       nr_turns = sksum_turns = strtoul(d, &stoi, 10);
+                       if (!str_empty(stoi)) xerror(NO, YES, YES, "[%s] nr_turns=%s: invalid number of turns", path, d);
+               }
+               else if (!strcmp(s, "ctr_mode")) {
+                       if (!strcasecmp(d, "ctr"))
+                               ctr_mode = TFC_MODE_CTR;
+                       else if (!strcasecmp(d, "stream"))
+                               ctr_mode = TFC_MODE_STREAM;
+                       else if (!strcasecmp(d, "cbc"))
+                               ctr_mode = TFC_MODE_CBC;
+                       else if (!strcasecmp(d, "ecb"))
+                               ctr_mode = TFC_MODE_ECB;
+                       else if (!strcasecmp(d, "xts"))
+                               ctr_mode = TFC_MODE_XTS;
+                       else if (!strcasecmp(d, "ocb"))
+                               ctr_mode = TFC_MODE_OCB;
+                       else xerror(NO, YES, YES, "[%s] ctr_mode=%s: invalid mode of operation", path, d);
+               }
+               else if (!strcmp(s, "tfc_salt")) {
+                       memset(tfc_salt, 0, TFC_MAX_SALT);
+                       tfc_saltsz = base64_decode((char *)tfc_salt, TFC_MAX_SALT, d, strlen(d));
+               }
+               else if (!strcmp(s, "macbits")) {
+                       macbits = strtoul(d, &stoi, 10);
+                       if (macbits == 0 || !str_empty(stoi) || macbits < 8
+                       || macbits > TF_MAX_BITS || macbits % 8)
+                               xerror(NO, YES, YES, "[%s] macbits=%s: invalid MAC bits setting", path, d);
+               }
+               else xerror(NO, YES, YES, "[%s] %s: unknown keyword", path, s);
+       }
+
+       memset(ln, 0, sizeof(ln));
+       fclose(f);
+}