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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:54:16 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:54:16 +0000
commit485f6ecd453d8a2fd8b9b9fadea03159d8b50797 (patch)
tree32451fa3cdd9321fb2591fada9891b2cb70a9cd1 /grub-core/disk/AFSplitter.c
parentInitial commit. (diff)
downloadgrub2-485f6ecd453d8a2fd8b9b9fadea03159d8b50797.tar.xz
grub2-485f6ecd453d8a2fd8b9b9fadea03159d8b50797.zip
Adding upstream version 2.06.upstream/2.06upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'grub-core/disk/AFSplitter.c')
-rw-r--r--grub-core/disk/AFSplitter.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/grub-core/disk/AFSplitter.c b/grub-core/disk/AFSplitter.c
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--- /dev/null
+++ b/grub-core/disk/AFSplitter.c
@@ -0,0 +1,95 @@
+/*
+ * AFsplitter - Anti forensic information splitter
+ * Copyright 2004, Clemens Fruhwirth <clemens@endorphin.org>
+ *
+ * AFsplitter diffuses information over a large stripe of data,
+ * therefor supporting secure data destruction.
+ *
+ * This program is grub_free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the grub_free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the grub_free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <grub/crypto.h>
+#include <grub/dl.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+
+GRUB_MOD_LICENSE ("GPLv2+");
+
+gcry_err_code_t AF_merge (const gcry_md_spec_t * hash, grub_uint8_t * src,
+ grub_uint8_t * dst, grub_size_t blocksize,
+ grub_size_t blocknumbers);
+
+static void
+diffuse (const gcry_md_spec_t * hash, grub_uint8_t * src,
+ grub_uint8_t * dst, grub_size_t size)
+{
+ grub_size_t i;
+ grub_uint32_t IV; /* host byte order independend hash IV */
+
+ grub_size_t fullblocks = size / hash->mdlen;
+ int padding = size % hash->mdlen;
+ grub_uint8_t final[GRUB_CRYPTO_MAX_MDLEN];
+ grub_uint8_t temp[sizeof (IV) + GRUB_CRYPTO_MAX_MDLEN];
+
+ /* hash block the whole data set with different IVs to produce
+ * more than just a single data block
+ */
+ for (i = 0; i < fullblocks; i++)
+ {
+ IV = grub_cpu_to_be32 (i);
+ grub_memcpy (temp, &IV, sizeof (IV));
+ grub_memcpy (temp + sizeof (IV), src + hash->mdlen * i, hash->mdlen);
+ grub_crypto_hash (hash, dst + hash->mdlen * i, temp,
+ sizeof (IV) + hash->mdlen);
+ }
+
+ if (padding)
+ {
+ IV = grub_cpu_to_be32 (i);
+ grub_memcpy (temp, &IV, sizeof (IV));
+ grub_memcpy (temp + sizeof (IV), src + hash->mdlen * i, padding);
+ grub_crypto_hash (hash, final, temp, sizeof (IV) + padding);
+ grub_memcpy (dst + hash->mdlen * i, final, padding);
+ }
+}
+
+/**
+ * Merges the splitted master key stored on disk into the original key
+ */
+gcry_err_code_t
+AF_merge (const gcry_md_spec_t * hash, grub_uint8_t * src, grub_uint8_t * dst,
+ grub_size_t blocksize, grub_size_t blocknumbers)
+{
+ grub_size_t i;
+ grub_uint8_t *bufblock;
+
+ if (hash->mdlen > GRUB_CRYPTO_MAX_MDLEN || hash->mdlen == 0)
+ return GPG_ERR_INV_ARG;
+
+ bufblock = grub_zalloc (blocksize);
+ if (bufblock == NULL)
+ return GPG_ERR_OUT_OF_MEMORY;
+
+ grub_memset (bufblock, 0, blocksize);
+ for (i = 0; i < blocknumbers - 1; i++)
+ {
+ grub_crypto_xor (bufblock, src + (blocksize * i), bufblock, blocksize);
+ diffuse (hash, bufblock, bufblock, blocksize);
+ }
+ grub_crypto_xor (dst, src + (i * blocksize), bufblock, blocksize);
+
+ grub_free (bufblock);
+ return GPG_ERR_NO_ERROR;
+}