crypto: add block encryption framework

Add a generic framework for supporting different block encryption
formats. Upon instantiating a QCryptoBlock object, it will read
the encryption header and extract the encryption keys. It is
then possible to call methods to encrypt/decrypt data buffers.

There is also a mode whereby it will create/initialize a new
encryption header on a previously unformatted volume.

The initial framework comes with support for the legacy QCow
AES based encryption. This enables code in the QCow driver to
be consolidated later.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

3 files changed, 242 insertions, 0 deletions

diff --git a/tests/.gitignore b/tests/.gitignore
index b3170ba33b..5f30cbea07 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -13,6 +13,7 @@ test-bitops
 test-blockjob-txn
 test-coroutine
 test-crypto-afsplit
+test-crypto-block
 test-crypto-cipher
 test-crypto-hash
 test-crypto-ivgen
diff --git a/tests/Makefile b/tests/Makefile
index e060061a58..60371ca008 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -96,6 +96,7 @@ check-unit-$(if $(CONFIG_NETTLE),y,$(CONFIG_GCRYPT_KDF)) += tests/test-crypto-pb
 check-unit-y += tests/test-crypto-ivgen$(EXESUF)
 check-unit-y += tests/test-crypto-afsplit$(EXESUF)
 check-unit-y += tests/test-crypto-xts$(EXESUF)
+check-unit-y += tests/test-crypto-block$(EXESUF)
 
 check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
 
@@ -504,6 +505,7 @@ tests/test-io-channel-buffer$(EXESUF): tests/test-io-channel-buffer.o \
 tests/test-crypto-pbkdf$(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 $(test-crypto-obj-y)
+tests/test-crypto-block$(EXESUF): tests/test-crypto-block.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
diff --git a/tests/test-crypto-block.c b/tests/test-crypto-block.c
new file mode 100644
index 0000000000..3f65383a1b
--- /dev/null
+++ b/tests/test-crypto-block.c
@@ -0,0 +1,239 @@
+/*
+ * QEMU Crypto block encryption
+ *
+ * Copyright (c) 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/block.h"
+#include "qemu/buffer.h"
+#include "crypto/secret.h"
+
+static QCryptoBlockCreateOptions qcow_create_opts = {
+    .format = Q_CRYPTO_BLOCK_FORMAT_QCOW,
+    .u.qcow = {
+        .has_key_secret = true,
+        .key_secret = (char *)"sec0",
+    },
+};
+
+static QCryptoBlockOpenOptions qcow_open_opts = {
+    .format = Q_CRYPTO_BLOCK_FORMAT_QCOW,
+    .u.qcow = {
+        .has_key_secret = true,
+        .key_secret = (char *)"sec0",
+    },
+};
+
+static struct QCryptoBlockTestData {
+    const char *path;
+    QCryptoBlockCreateOptions *create_opts;
+    QCryptoBlockOpenOptions *open_opts;
+
+    bool expect_header;
+
+    QCryptoCipherAlgorithm cipher_alg;
+    QCryptoCipherMode cipher_mode;
+    QCryptoHashAlgorithm hash_alg;
+
+    QCryptoIVGenAlgorithm ivgen_alg;
+    QCryptoCipherAlgorithm ivgen_hash;
+} test_data[] = {
+    {
+        .path = "/crypto/block/qcow",
+        .create_opts = &qcow_create_opts,
+        .open_opts = &qcow_open_opts,
+
+        .expect_header = false,
+
+        .cipher_alg = QCRYPTO_CIPHER_ALG_AES_128,
+        .cipher_mode = QCRYPTO_CIPHER_MODE_CBC,
+
+        .ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64,
+    },
+};
+
+
+static ssize_t test_block_read_func(QCryptoBlock *block,
+                                    size_t offset,
+                                    uint8_t *buf,
+                                    size_t buflen,
+                                    Error **errp,
+                                    void *opaque)
+{
+    Buffer *header = opaque;
+
+    g_assert_cmpint(offset + buflen, <=, header->capacity);
+
+    memcpy(buf, header->buffer + offset, buflen);
+
+    return buflen;
+}
+
+
+static ssize_t test_block_init_func(QCryptoBlock *block,
+                                    size_t headerlen,
+                                    Error **errp,
+                                    void *opaque)
+{
+    Buffer *header = opaque;
+
+    g_assert_cmpint(header->capacity, ==, 0);
+
+    buffer_reserve(header, headerlen);
+
+    return headerlen;
+}
+
+
+static ssize_t test_block_write_func(QCryptoBlock *block,
+                                     size_t offset,
+                                     const uint8_t *buf,
+                                     size_t buflen,
+                                     Error **errp,
+                                     void *opaque)
+{
+    Buffer *header = opaque;
+
+    g_assert_cmpint(buflen + offset, <=, header->capacity);
+
+    memcpy(header->buffer + offset, buf, buflen);
+    header->offset = offset + buflen;
+
+    return buflen;
+}
+
+
+static Object *test_block_secret(void)
+{
+    return object_new_with_props(
+        TYPE_QCRYPTO_SECRET,
+        object_get_objects_root(),
+        "sec0",
+        &error_abort,
+        "data", "123456",
+        NULL);
+}
+
+static void test_block_assert_setup(const struct QCryptoBlockTestData *data,
+                                    QCryptoBlock *blk)
+{
+    QCryptoIVGen *ivgen;
+    QCryptoCipher *cipher;
+
+    ivgen = qcrypto_block_get_ivgen(blk);
+    cipher = qcrypto_block_get_cipher(blk);
+
+    g_assert(ivgen);
+    g_assert(cipher);
+
+    g_assert_cmpint(data->cipher_alg, ==, cipher->alg);
+    g_assert_cmpint(data->cipher_mode, ==, cipher->mode);
+    g_assert_cmpint(data->hash_alg, ==,
+                    qcrypto_block_get_kdf_hash(blk));
+
+    g_assert_cmpint(data->ivgen_alg, ==,
+                    qcrypto_ivgen_get_algorithm(ivgen));
+    g_assert_cmpint(data->ivgen_hash, ==,
+                    qcrypto_ivgen_get_hash(ivgen));
+}
+
+
+static void test_block(gconstpointer opaque)
+{
+    const struct QCryptoBlockTestData *data = opaque;
+    QCryptoBlock *blk;
+    Buffer header;
+    Object *sec = test_block_secret();
+
+    memset(&header, 0, sizeof(header));
+    buffer_init(&header, "header");
+
+    blk = qcrypto_block_create(data->create_opts,
+                               test_block_init_func,
+                               test_block_write_func,
+                               &header,
+                               &error_abort);
+    g_assert(blk);
+
+    if (data->expect_header) {
+        g_assert_cmpint(header.capacity, >, 0);
+    } else {
+        g_assert_cmpint(header.capacity, ==, 0);
+    }
+
+    test_block_assert_setup(data, blk);
+
+    qcrypto_block_free(blk);
+    object_unparent(sec);
+
+    /* Ensure we can't open without the secret */
+    blk = qcrypto_block_open(data->open_opts,
+                             test_block_read_func,
+                             &header,
+                             0,
+                             NULL);
+    g_assert(blk == NULL);
+
+    /* Ensure we can't open without the secret, unless NO_IO */
+    blk = qcrypto_block_open(data->open_opts,
+                             test_block_read_func,
+                             &header,
+                             QCRYPTO_BLOCK_OPEN_NO_IO,
+                             &error_abort);
+
+    g_assert(qcrypto_block_get_cipher(blk) == NULL);
+    g_assert(qcrypto_block_get_ivgen(blk) == NULL);
+
+    qcrypto_block_free(blk);
+
+
+    /* Now open for real with secret */
+    sec = test_block_secret();
+    blk = qcrypto_block_open(data->open_opts,
+                             test_block_read_func,
+                             &header,
+                             0,
+                             &error_abort);
+    g_assert(blk);
+
+    test_block_assert_setup(data, blk);
+
+    qcrypto_block_free(blk);
+
+    object_unparent(sec);
+
+    buffer_free(&header);
+}
+
+
+int main(int argc, char **argv)
+{
+    gsize i;
+
+    module_call_init(MODULE_INIT_QOM);
+    g_test_init(&argc, &argv, NULL);
+
+    g_assert(qcrypto_init(NULL) == 0);
+
+    for (i = 0; i < G_N_ELEMENTS(test_data); i++) {
+        g_test_add_data_func(test_data[i].path, &test_data[i], test_block);
+    }
+
+    return g_test_run();
+}