X-Git-Url: https://jxself.org/git/?a=blobdiff_plain;f=tfc_error.c;h=905ae40213bb501be0089218718f38ed261cb0af;hb=3699c1f4ba441ce91f5fa674e73c3c4fa0264578;hp=5729de0f42ff26ad18db6e37da6f81c4d4c7e934;hpb=72672c5cb76597fdc07cbc9bc190394d1c1d3ee1;p=tfcrypt.git

diff --git a/tfc_error.c b/tfc_error.c
index 5729de0..905ae40 100644
--- a/tfc_error.c
+++ b/tfc_error.c
@@ -2,7 +2,7 @@
  * tfcrypt -- high security Threefish encryption tool.
  *
  * tfcrypt is copyrighted:
- * Copyright (C) 2012-2018 Andrey Rys. All rights reserved.
+ * Copyright (C) 2012-2019 Andrey Rys. All rights reserved.
  *
  * tfcrypt is licensed to you under the terms of std. MIT/X11 license:
  *
@@ -176,6 +176,11 @@ void usage(void)
 	tfc_say("    head: when decrypting, read CTR from beginning of stream,");
 	tfc_say("    rand: generate random CTR and write it to beginning of stream,");
 	tfc_say("    zero: assume zero CTR is used, do not read from and write it to stream,");
+	tfc_say("    hexc:nr[,hexc:nr,...]: construct counter from given pattern.");
+	tfc_say("      Example: \"ff:124,08:2,80:2\" will fill counter first with 124 0xff bytes,");
+	tfc_say("      then with 2 0x08 bytes, then 2 0x80 bytes. To fill with zeroes, it is");
+	tfc_say("      simple to specify just a \"0:128\" as a pattern. Note that bytes that");
+	tfc_say("      exceed CTR space will be just dropped, and any unused bytes are set to zeroes.");
 	tfc_say("    <file>: read CTR from given file (both when encrypting/decrypting).");
 	tfc_say("      default is to derive CTR from user provided password or keyfile with");
 	tfc_say("      a single Skein function turn over derived, %u byte raw key", TFC_U(TF_KEY_SIZE));