VeraCrypt
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authorMounir IDRASSI <mounir.idrassi@idrix.fr>2019-02-08 01:48:12 +0100
committerMounir IDRASSI <mounir.idrassi@idrix.fr>2019-02-08 01:50:12 +0100
commitba5da0946c3abaa93d1161ca512c3c326cda3736 (patch)
tree128c238dea40ac0de0c7de8e0b02810eabc8e564 /src/Crypto/chachaRng.h
parente5b9cee8681dc45340321f759079b344a3b2676c (diff)
downloadVeraCrypt-ba5da0946c3abaa93d1161ca512c3c326cda3736.tar.gz
VeraCrypt-ba5da0946c3abaa93d1161ca512c3c326cda3736.zip
Windows: Add implementation of ChaCha20 based random generator. Use it for driver need of random bytes (currently only wipe bytes but more to come later).
Diffstat (limited to 'src/Crypto/chachaRng.h')
-rw-r--r--src/Crypto/chachaRng.h63
1 files changed, 63 insertions, 0 deletions
diff --git a/src/Crypto/chachaRng.h b/src/Crypto/chachaRng.h
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+++ b/src/Crypto/chachaRng.h
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+/* $OpenBSD: arc4random.c,v 1.54 2015/09/13 08:31:47 guenther Exp $ */
+
+/*
+ * Copyright (c) 1996, David Mazieres <dm@uun.org>
+ * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
+ * Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
+ * Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * ChaCha based random number generator for OpenBSD.
+ */
+
+/*
+ * Adapted for VeraCrypt
+ */
+
+#ifndef HEADER_Crypto_ChaChaRng
+#define HEADER_Crypto_ChaChaRng
+
+#include "chacha256.h"
+
+#define CHACHA20RNG_KEYSZ 32
+#define CHACHA20RNG_IVSZ 8
+#define CHACHA20RNG_BLOCKSZ 64
+#define CHACHA20RNG_RSBUFSZ (16*CHACHA20RNG_BLOCKSZ)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void (*GetRandSeedFn)(unsigned char* pbRandSeed, size_t cbRandSeed);
+
+typedef struct
+{
+ ChaCha256Ctx m_chachaCtx; /* ChaCha20 context */
+ unsigned char m_rs_buf[CHACHA20RNG_RSBUFSZ]; /* keystream blocks */
+ size_t m_rs_have; /* valid bytes at end of rs_buf */
+ size_t m_rs_count; /* bytes till reseed */
+ GetRandSeedFn m_getRandSeedCallback;
+} ChaCha20RngCtx;
+
+/* key length must be equal to 40 bytes (CHACHA20RNG_KEYSZ + CHACHA20RNG_IVSZ) */
+void ChaCha20RngInit (ChaCha20RngCtx* pCtx, const unsigned char* key, GetRandSeedFn rngCallback, size_t InitialBytesToSkip);
+void ChaCha20RngGetBytes (ChaCha20RngCtx* pCtx, unsigned char* buffer, size_t bufferLen);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif