From 72672c5cb76597fdc07cbc9bc190394d1c1d3ee1 Mon Sep 17 00:00:00 2001
From: Andrey Rys <rys@lynxlynx.ru>
Date: Thu, 25 Apr 2019 03:22:02 +0700
Subject: [PATCH] Display hash of current defaults.

---
 VERSION        |  2 +-
 tfc_conf.c     | 32 ++++++++++++++++++++++++++++++++
 tfc_error.c    |  4 ++++
 tfcrypt.h      |  1 +
 tfcrypt_defs.h |  2 ++
 5 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/VERSION b/VERSION
index f04c001..64bb6b7 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-29
+30
diff --git a/tfc_conf.c b/tfc_conf.c
index c583b86..da45231 100644
--- a/tfc_conf.c
+++ b/tfc_conf.c
@@ -104,3 +104,35 @@ _nspc:
 	memset(ln, 0, sizeof(ln));
 	fclose(f);
 }
+
+void hash_defaults(char *uhash, size_t szuhash)
+{
+	struct skein sk;
+	char shash[56];
+	const char *mode;
+	tfc_byte hash[TF_FROM_BITS(256)];
+
+	skein_init(&sk, 256);
+
+	skein_update(&sk, tfc_salt, tfc_saltsz);
+
+	memset(shash, 0, sizeof(shash));
+	sprintf(shash, "%zu", nr_turns);
+	skein_update(&sk, shash, strlen(shash));
+
+	mode = tfc_modename(ctr_mode);
+	skein_update(&sk, mode, strlen(mode));
+
+	memset(shash, 0, sizeof(shash));
+	sprintf(shash, "%zu", macbits);
+	skein_update(&sk, shash, strlen(shash));
+
+	skein_update(&sk, do_full_key ? "1" : "0", 1);
+
+	skein_final(hash, &sk);
+	memset(shash, 0, sizeof(shash));
+	base64_encode(shash, (const char *)hash, sizeof(hash));
+	memset(hash, 0, sizeof(hash));
+
+	xstrlcpy(uhash, shash, szuhash);
+}
diff --git a/tfc_error.c b/tfc_error.c
index c4e51f1..5729de0 100644
--- a/tfc_error.c
+++ b/tfc_error.c
@@ -91,7 +91,11 @@ void usage(void)
 	tfc_yesno is_embedded_prog = NO;
 
 	if (optopt == 'V') {
+		char shash[64];
 		tfc_say("tfcrypt toolkit, version %s.", _TFCRYPT_VERSION);
+		hash_defaults(shash, sizeof(shash));
+		tfc_say("Defaults hash: %s", shash);
+		memset(shash, 0, sizeof(shash));
 		xexit(0);
 	}
 
diff --git a/tfcrypt.h b/tfcrypt.h
index 49073c9..e33e858 100644
--- a/tfcrypt.h
+++ b/tfcrypt.h
@@ -207,6 +207,7 @@ void skein(void *hash, size_t bits, const void *key, const void *data, size_t sz
 tfc_yesno skeinfd(void *hash, size_t bits, const void *key, int fd, tfc_fsize offset, tfc_fsize readto);
 
 void read_defaults(const char *path, tfc_yesno noerr);
+void hash_defaults(char *uhash, size_t szuhash);
 
 void gen_write_bytes(const char *foutname, tfc_fsize offset, tfc_fsize nrbytes);
 void do_edbase64(char **fargv);
diff --git a/tfcrypt_defs.h b/tfcrypt_defs.h
index c7b3ae7..9e54d80 100644
--- a/tfcrypt_defs.h
+++ b/tfcrypt_defs.h
@@ -1,6 +1,8 @@
 #ifndef _TFCRYPT_DEFAULTS_HEADER
 #define _TFCRYPT_DEFAULTS_HEADER
 
+/* 5uouFzawL37Un6RtVqWbv0SOX48ew/xntAG5sNaOSlk= */
+
 size_t nr_turns = 262144;
 int ctr_mode = TFC_MODE_XTS;
 size_t macbits = TF_MAX_BITS;
-- 
2.31.1