@@ -17,6 +17,7 @@ crypto-obj-y += ivgen.o
crypto-obj-y += ivgen-essiv.o
crypto-obj-y += ivgen-plain.o
crypto-obj-y += ivgen-plain64.o
+crypto-obj-y += afsplit.o
# Let the userspace emulators avoid linking gnutls/etc
crypto-aes-obj-y = aes.o
new file mode 100644
@@ -0,0 +1,158 @@
+/*
+ * QEMU Crypto anti forensic information splitter
+ *
+ * Copyright (c) 2015-2016 Red Hat, Inc.
+ *
+ * Derived from cryptsetup package lib/luks1/af.c
+ *
+ * Copyright (C) 2004, Clemens Fruhwirth <clemens@endorphin.org>
+ * Copyright (C) 2009-2012, Red Hat, Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "crypto/afsplit.h"
+#include "crypto/random.h"
+
+
+static void qcrypto_afsplit_xor(size_t blocklen,
+ const uint8_t *in1,
+ const uint8_t *in2,
+ uint8_t *out)
+{
+ size_t i;
+ for (i = 0; i < blocklen; i++) {
+ out[i] = in1[i] ^ in2[i];
+ }
+}
+
+
+static int qcrypto_afsplit_hash(QCryptoHashAlgorithm hash,
+ size_t blocklen,
+ uint8_t *block,
+ Error **errp)
+{
+ size_t digestlen = qcrypto_hash_digest_len(hash);
+
+ size_t hashcount = blocklen / digestlen;
+ size_t finallen = blocklen % digestlen;
+ uint32_t i;
+
+ if (finallen) {
+ hashcount++;
+ } else {
+ finallen = digestlen;
+ }
+
+ for (i = 0; i < hashcount; i++) {
+ uint8_t *out = NULL;
+ size_t outlen = 0;
+ uint32_t iv = cpu_to_be32(i);
+ struct iovec in[] = {
+ { .iov_base = &iv,
+ .iov_len = sizeof(iv) },
+ { .iov_base = block + (i * digestlen),
+ .iov_len = (i == (hashcount - 1)) ? finallen : digestlen },
+ };
+
+ if (qcrypto_hash_bytesv(hash,
+ in,
+ G_N_ELEMENTS(in),
+ &out, &outlen,
+ errp) < 0) {
+ return -1;
+ }
+
+ assert(outlen == digestlen);
+ memcpy(block + (i * digestlen), out,
+ (i == (hashcount - 1)) ? finallen : digestlen);
+ g_free(out);
+ }
+
+ return 0;
+}
+
+
+int qcrypto_afsplit_encode(QCryptoHashAlgorithm hash,
+ size_t blocklen,
+ uint32_t stripes,
+ const uint8_t *in,
+ uint8_t *out,
+ Error **errp)
+{
+ uint8_t *block = g_new0(uint8_t, blocklen);
+ size_t i;
+ int ret = -1;
+
+ for (i = 0; i < (stripes - 1); i++) {
+ if (qcrypto_random_bytes(out + (i * blocklen), blocklen, errp) < 0) {
+ goto cleanup;
+ }
+
+ qcrypto_afsplit_xor(blocklen,
+ out + (i * blocklen),
+ block,
+ block);
+ if (qcrypto_afsplit_hash(hash, blocklen, block,
+ errp) < 0) {
+ goto cleanup;
+ }
+ }
+ qcrypto_afsplit_xor(blocklen,
+ in,
+ block,
+ out + (i * blocklen));
+ ret = 0;
+
+ cleanup:
+ g_free(block);
+ return ret;
+}
+
+
+int qcrypto_afsplit_decode(QCryptoHashAlgorithm hash,
+ size_t blocklen,
+ uint32_t stripes,
+ const uint8_t *in,
+ uint8_t *out,
+ Error **errp)
+{
+ uint8_t *block = g_new0(uint8_t, blocklen);
+ size_t i;
+ int ret = -1;
+
+ for (i = 0; i < (stripes - 1); i++) {
+ qcrypto_afsplit_xor(blocklen,
+ in + (i * blocklen),
+ block,
+ block);
+ if (qcrypto_afsplit_hash(hash, blocklen, block,
+ errp) < 0) {
+ goto cleanup;
+ }
+ }
+
+ qcrypto_afsplit_xor(blocklen,
+ in + (i * blocklen),
+ block,
+ out);
+
+ ret = 0;
+
+ cleanup:
+ g_free(block);
+ return ret;
+}
new file mode 100644
@@ -0,0 +1,135 @@
+/*
+ * QEMU Crypto anti forensic information splitter
+ *
+ * Copyright (c) 2015-2016 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef QCRYPTO_AFSPLIT_H__
+#define QCRYPTO_AFSPLIT_H__
+
+#include "crypto/hash.h"
+
+/**
+ * This module implements the anti-forensic splitter that is specified
+ * as part of the LUKS format:
+ *
+ * http://clemens.endorphin.org/cryptography
+ * http://clemens.endorphin.org/TKS1-draft.pdf
+ *
+ * The core idea is to take a short piece of data (key material)
+ * and process it to expand it to a much larger piece of data.
+ * The expansion process is reversible, to obtain the original
+ * short data. The key property of the expansion is that if any
+ * byte in the larger data set is changed / missing, it should be
+ * impossible to recreate the original short data.
+ *
+ * <example>
+ * <title>Creating a large split key for storage</title>
+ * <programlisting>
+ * size_t nkey = 32;
+ * uint32_t stripes = 32768; // To produce a 1 MB split key
+ * uint8_t *masterkey = ....a 32-byte AES key...
+ * uint8_t *splitkey;
+ *
+ * splitkey = g_new0(uint8_t, nkey * stripes);
+ *
+ * if (qcrypto_afsplit_encode(QCRYPTO_HASH_ALG_SHA256,
+ * nkey, stripes,
+ * masterkey, splitkey, errp) < 0) {
+ * g_free(splitkey);
+ * g_free(masterkey);
+ * return -1;
+ * }
+ *
+ * ...store splitkey somewhere...
+ *
+ * g_free(splitkey);
+ * g_free(masterkey);
+ * </programlisting>
+ * </example>
+ *
+ * <example>
+ * <title>Retrieving a master key from storage</title>
+ * <programlisting>
+ * size_t nkey = 32;
+ * uint32_t stripes = 32768; // To produce a 1 MB split key
+ * uint8_t *masterkey;
+ * uint8_t *splitkey = .... read in 1 MB of data...
+ *
+ * masterkey = g_new0(uint8_t, nkey);
+ *
+ * if (qcrypto_afsplit_decode(QCRYPTO_HASH_ALG_SHA256,
+ * nkey, stripes,
+ * splitkey, masterkey, errp) < 0) {
+ * g_free(splitkey);
+ * g_free(masterkey);
+ * return -1;
+ * }
+ *
+ * ..decrypt data with masterkey...
+ *
+ * g_free(splitkey);
+ * g_free(masterkey);
+ * </programlisting>
+ * </example>
+ */
+
+/**
+ * qcrypto_afsplit_encode:
+ * @hash: the hash algorithm to use for data expansion
+ * @blocklen: the size of @in in bytes
+ * @stripes: the number of times to expand @in in size
+ * @in: the master key to be expanded in size
+ * @out: preallocated buffer to hold the split key
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Split the data in @in, which is @blocklen bytes in
+ * size, to form a larger piece of data @out, which is
+ * @blocklen * @stripes bytes in size.
+ *
+ * Returns: 0 on success, -1 on error;
+ */
+int qcrypto_afsplit_encode(QCryptoHashAlgorithm hash,
+ size_t blocklen,
+ uint32_t stripes,
+ const uint8_t *in,
+ uint8_t *out,
+ Error **errp);
+
+/**
+ * qcrypto_afsplit_decode:
+ * @hash: the hash algorithm to use for data compression
+ * @blocklen: the size of @out in bytes
+ * @stripes: the number of times to decrease @in in size
+ * @in: the split key to be recombined
+ * @out: preallocated buffer to hold the master key
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Join the data in @in, which is @blocklen * @stripes
+ * bytes in size, to form the original small piece of
+ * data @out, which is @blocklen bytes in size.
+ *
+ * Returns: 0 on success, -1 on error;
+ */
+int qcrypto_afsplit_decode(QCryptoHashAlgorithm hash,
+ size_t blocklen,
+ uint32_t stripes,
+ const uint8_t *in,
+ uint8_t *out,
+ Error **errp);
+
+#endif /* QCRYPTO_AFSPLIT_H__ */
@@ -12,6 +12,7 @@ test-base64
test-bitops
test-blockjob-txn
test-coroutine
+test-crypto-afsplit
test-crypto-cipher
test-crypto-hash
test-crypto-ivgen
@@ -94,6 +94,7 @@ check-unit-y += tests/test-io-channel-buffer$(EXESUF)
check-unit-y += tests/test-base64$(EXESUF)
check-unit-$(if $(CONFIG_NETTLE),y,$(CONFIG_GCRYPT_KDF)) += tests/test-crypto-pbkdf$(EXESUF)
check-unit-y += tests/test-crypto-ivgen$(EXESUF)
+check-unit-y += tests/test-crypto-afsplit$(EXESUF)
check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
@@ -500,6 +501,7 @@ tests/test-io-channel-buffer$(EXESUF): tests/test-io-channel-buffer.o \
tests/io-channel-helpers.o $(test-io-obj-y)
tests/test-crypto-pbkdf$(EXESUF): tests/test-crypto-pbkdf.o $(test-crypto-obj-y)
tests/test-crypto-ivgen$(EXESUF): tests/test-crypto-ivgen.o $(test-crypto-obj-y)
+tests/test-crypto-afsplit$(EXESUF): tests/test-crypto-afsplit.o $(test-crypto-obj-y)
libqos-obj-y = tests/libqos/pci.o tests/libqos/fw_cfg.o tests/libqos/malloc.o
libqos-obj-y += tests/libqos/i2c.o tests/libqos/libqos.o
new file mode 100644
@@ -0,0 +1,193 @@
+/*
+ * QEMU Crypto anti-forensic splitter
+ *
+ * Copyright (c) 2015-2016 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "crypto/init.h"
+#include "crypto/afsplit.h"
+
+typedef struct QCryptoAFSplitTestData QCryptoAFSplitTestData;
+struct QCryptoAFSplitTestData {
+ const char *path;
+ QCryptoHashAlgorithm hash;
+ uint32_t stripes;
+ size_t blocklen;
+ const uint8_t *key;
+ const uint8_t *splitkey;
+};
+
+static QCryptoAFSplitTestData test_data[] = {
+ {
+ .path = "/crypto/afsplit/sha256/5",
+ .hash = QCRYPTO_HASH_ALG_SHA256,
+ .stripes = 5,
+ .blocklen = 32,
+ .key = (const uint8_t *)
+ "\x00\x01\x02\x03\x04\x05\x06\x07"
+ "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
+ "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7"
+ "\xa8\xa9\xaa\xab\xac\xad\xae\xaf",
+ .splitkey = (const uint8_t *)
+ "\xfd\xd2\x73\xb1\x7d\x99\x93\x34"
+ "\x70\xde\xfa\x07\xc5\xac\x58\xd2"
+ "\x30\x67\x2f\x1a\x35\x43\x60\x7d"
+ "\x77\x02\xdb\x62\x3c\xcb\x2c\x33"
+ "\x48\x08\xb6\xf1\x7c\xa3\x20\xa0"
+ "\xad\x2d\x4c\xf3\xcd\x18\x6f\x53"
+ "\xf9\xe8\xe7\x59\x27\x3c\xa9\x54"
+ "\x61\x87\xb3\xaf\xf6\xf7\x7e\x64"
+ "\x86\xaa\x89\x7f\x1f\x9f\xdb\x86"
+ "\xf4\xa2\x16\xff\xa3\x4f\x8c\xa1"
+ "\x59\xc4\x23\x34\x28\xc4\x77\x71"
+ "\x83\xd4\xcd\x8e\x89\x1b\xc7\xc5"
+ "\xae\x4d\xa9\xcd\xc9\x72\x85\x70"
+ "\x13\x68\x52\x83\xfc\xb8\x11\x72"
+ "\xba\x3d\xc6\x4a\x28\xfa\xe2\x86"
+ "\x7b\x27\xab\x58\xe1\xa4\xca\xf6"
+ "\x9e\xbc\xfe\x0c\x92\x79\xb3\xec"
+ "\x1c\x5f\x79\x3b\x0d\x1e\xaa\x1a"
+ "\x77\x0f\x70\x19\x4b\xc8\x80\xee"
+ "\x27\x7c\x6e\x4a\x91\x96\x5c\xf4"
+ },
+ {
+ .path = "/crypto/afsplit/sha256/5000",
+ .hash = QCRYPTO_HASH_ALG_SHA256,
+ .stripes = 5000,
+ .blocklen = 16,
+ .key = (const uint8_t *)
+ "\x00\x01\x02\x03\x04\x05\x06\x07"
+ "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
+ },
+ {
+ .path = "/crypto/afsplit/sha1/1000",
+ .hash = QCRYPTO_HASH_ALG_SHA1,
+ .stripes = 1000,
+ .blocklen = 32,
+ .key = (const uint8_t *)
+ "\x00\x01\x02\x03\x04\x05\x06\x07"
+ "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
+ "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7"
+ "\xa8\xa9\xaa\xab\xac\xad\xae\xaf",
+ },
+ {
+ .path = "/crypto/afsplit/sha256/big",
+ .hash = QCRYPTO_HASH_ALG_SHA256,
+ .stripes = 1000,
+ .blocklen = 64,
+ .key = (const uint8_t *)
+ "\x00\x01\x02\x03\x04\x05\x06\x07"
+ "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
+ "\x00\x01\x02\x03\x04\x05\x06\x07"
+ "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
+ "\x00\x01\x02\x03\x04\x05\x06\x07"
+ "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f"
+ "\x00\x01\x02\x03\x04\x05\x06\x07"
+ "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
+ },
+};
+
+
+static inline char hex(int i)
+{
+ if (i < 10) {
+ return '0' + i;
+ }
+ return 'a' + (i - 10);
+}
+
+static char *hex_string(const uint8_t *bytes,
+ size_t len)
+{
+ char *hexstr = g_new0(char, len * 2 + 1);
+ size_t i;
+
+ for (i = 0; i < len; i++) {
+ hexstr[i * 2] = hex((bytes[i] >> 4) & 0xf);
+ hexstr[i * 2 + 1] = hex(bytes[i] & 0xf);
+ }
+ hexstr[len * 2] = '\0';
+
+ return hexstr;
+}
+
+static void test_afsplit(const void *opaque)
+{
+ const QCryptoAFSplitTestData *data = opaque;
+ size_t splitlen = data->blocklen * data->stripes;
+ uint8_t *splitkey = g_new0(uint8_t, splitlen);
+ uint8_t *key = g_new0(uint8_t, data->blocklen);
+ gchar *expect, *actual;
+
+ /* First time we round-trip the key */
+ qcrypto_afsplit_encode(data->hash,
+ data->blocklen, data->stripes,
+ data->key, splitkey,
+ &error_abort);
+
+ qcrypto_afsplit_decode(data->hash,
+ data->blocklen, data->stripes,
+ splitkey, key,
+ &error_abort);
+
+ expect = hex_string(data->key, data->blocklen);
+ actual = hex_string(key, data->blocklen);
+
+ g_assert_cmpstr(actual, ==, expect);
+
+ g_free(actual);
+ g_free(expect);
+
+ /* Second time we merely try decoding a previous split */
+ if (data->splitkey) {
+ memset(key, 0, data->blocklen);
+
+ qcrypto_afsplit_decode(data->hash,
+ data->blocklen, data->stripes,
+ data->splitkey, key,
+ &error_abort);
+
+ expect = hex_string(data->key, data->blocklen);
+ actual = hex_string(key, data->blocklen);
+
+ g_assert_cmpstr(actual, ==, expect);
+
+ g_free(actual);
+ g_free(expect);
+ }
+
+ g_free(key);
+ g_free(splitkey);
+}
+
+int main(int argc, char **argv)
+{
+ size_t i;
+
+ g_test_init(&argc, &argv, NULL);
+
+ g_assert(qcrypto_init(NULL) == 0);
+
+ for (i = 0; i < G_N_ELEMENTS(test_data); i++) {
+ if (!qcrypto_hash_supports(test_data[i].hash)) {
+ continue;
+ }
+ g_test_add_data_func(test_data[i].path, &test_data[i], test_afsplit);
+ }
+ return g_test_run();
+}