[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v1 05/15] crypto: add block encryption framework
From: |
Daniel P. Berrange |
Subject: |
[Qemu-devel] [PATCH v1 05/15] crypto: add block encryption framework |
Date: |
Tue, 12 Jan 2016 18:56:12 +0000 |
Add a generic framework for support 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.
Signed-off-by: Daniel P. Berrange <address@hidden>
---
crypto/Makefile.objs | 2 +
crypto/block-qcowaes.c | 165 ++++++++++++++++++++++++++++++++
crypto/block-qcowaes.h | 28 ++++++
crypto/block.c | 254 +++++++++++++++++++++++++++++++++++++++++++++++++
crypto/blockpriv.h | 89 +++++++++++++++++
include/crypto/block.h | 222 ++++++++++++++++++++++++++++++++++++++++++
qapi/crypto.json | 65 +++++++++++++
7 files changed, 825 insertions(+)
create mode 100644 crypto/block-qcowaes.c
create mode 100644 crypto/block-qcowaes.h
create mode 100644 crypto/block.c
create mode 100644 crypto/blockpriv.h
create mode 100644 include/crypto/block.h
diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs
index 1e08a3a..b5b32a6 100644
--- a/crypto/Makefile.objs
+++ b/crypto/Makefile.objs
@@ -15,6 +15,8 @@ crypto-obj-y += ivgen-essiv.o
crypto-obj-y += ivgen-plain.o
crypto-obj-y += ivgen-plain64.o
crypto-obj-y += afsplit.o
+crypto-obj-y += block.o
+crypto-obj-y += block-qcowaes.o
# Let the userspace emulators avoid linking gnutls/etc
crypto-aes-obj-y = aes.o
diff --git a/crypto/block-qcowaes.c b/crypto/block-qcowaes.c
new file mode 100644
index 0000000..cf8ff50
--- /dev/null
+++ b/crypto/block-qcowaes.c
@@ -0,0 +1,165 @@
+/*
+ * QEMU Crypto block device encryption QCOWAES format
+ *
+ * Copyright (c) 2015 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 "config-host.h"
+
+#include "crypto/block-qcowaes.h"
+#include "crypto/secret.h"
+
+static gboolean
+qcrypto_block_qcowaes_has_format(const uint8_t *buf G_GNUC_UNUSED,
+ size_t buf_size G_GNUC_UNUSED)
+{
+ return false;
+}
+
+
+static int
+qcrypto_block_qcowaes_init(QCryptoBlock *block,
+ const char *keyid,
+ Error **errp)
+{
+ char *password;
+ int ret;
+ uint8_t keybuf[16];
+ int len, i;
+
+ memset(keybuf, 0, 16);
+
+ password = qcrypto_secret_lookup_as_utf8(keyid, errp);
+ if (!password) {
+ return -1;
+ }
+
+ len = strlen(password);
+ if (len > 16) {
+ len = 16;
+ }
+ for (i = 0; i < len; i++) {
+ keybuf[i] = password[i];
+ }
+ g_free(password);
+
+ block->niv = qcrypto_cipher_get_iv_len(QCRYPTO_CIPHER_ALG_AES_128,
+ QCRYPTO_CIPHER_MODE_CBC);
+ block->ivgen = qcrypto_ivgen_new(QCRYPTO_IVGEN_ALG_PLAIN64,
+ 0, 0, NULL, 0, errp);
+ if (!block->ivgen) {
+ ret = -ENOTSUP;
+ goto fail;
+ }
+
+ block->cipher = qcrypto_cipher_new(QCRYPTO_CIPHER_ALG_AES_128,
+ QCRYPTO_CIPHER_MODE_CBC,
+ keybuf, G_N_ELEMENTS(keybuf),
+ errp);
+ if (!block->cipher) {
+ ret = -ENOTSUP;
+ goto fail;
+ }
+
+ block->payload_offset = 0;
+
+ return 0;
+
+ fail:
+ qcrypto_cipher_free(block->cipher);
+ qcrypto_ivgen_free(block->ivgen);
+ return ret;
+}
+
+
+static int
+qcrypto_block_qcowaes_open(QCryptoBlock *block,
+ QCryptoBlockOpenOptions *options,
+ QCryptoBlockReadFunc readfunc G_GNUC_UNUSED,
+ void *opaque G_GNUC_UNUSED,
+ unsigned int flags,
+ Error **errp)
+{
+ if (flags & QCRYPTO_BLOCK_OPEN_NO_IO) {
+ return 0;
+ } else {
+ if (!options->u.qcowaes->key_id) {
+ error_setg(errp, "Parameter 'key-id' is required to initialize
cipher");
+ return -1;
+ }
+ return qcrypto_block_qcowaes_init(block, options->u.qcowaes->key_id,
errp);
+ }
+}
+
+
+static int
+qcrypto_block_qcowaes_create(QCryptoBlock *block,
+ QCryptoBlockCreateOptions *options,
+ QCryptoBlockInitFunc initfunc G_GNUC_UNUSED,
+ QCryptoBlockWriteFunc writefunc G_GNUC_UNUSED,
+ void *opaque G_GNUC_UNUSED,
+ Error **errp)
+{
+ if (!options->u.qcowaes->key_id) {
+ error_setg(errp, "Parameter 'key-id' is required to initialize
cipher");
+ return -1;
+ }
+ /* QCow2 has no special header, since everything is hardwired */
+ return qcrypto_block_qcowaes_init(block, options->u.qcowaes->key_id, errp);
+}
+
+
+static void
+qcrypto_block_qcowaes_cleanup(QCryptoBlock *block)
+{
+}
+
+
+static int
+qcrypto_block_qcowaes_decrypt(QCryptoBlock *block,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp)
+{
+ return qcrypto_block_decrypt_helper(block->cipher,
+ block->niv, block->ivgen,
+ startsector, buf, len, errp);
+}
+
+
+static int
+qcrypto_block_qcowaes_encrypt(QCryptoBlock *block,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp)
+{
+ return qcrypto_block_encrypt_helper(block->cipher,
+ block->niv, block->ivgen,
+ startsector, buf, len, errp);
+}
+
+
+const QCryptoBlockDriver qcrypto_block_driver_qcowaes = {
+ .open = qcrypto_block_qcowaes_open,
+ .create = qcrypto_block_qcowaes_create,
+ .cleanup = qcrypto_block_qcowaes_cleanup,
+ .decrypt = qcrypto_block_qcowaes_decrypt,
+ .encrypt = qcrypto_block_qcowaes_encrypt,
+ .has_format = qcrypto_block_qcowaes_has_format,
+};
diff --git a/crypto/block-qcowaes.h b/crypto/block-qcowaes.h
new file mode 100644
index 0000000..e43b7e5
--- /dev/null
+++ b/crypto/block-qcowaes.h
@@ -0,0 +1,28 @@
+/*
+ * QEMU Crypto block device encryption QCow AES format
+ *
+ * Copyright (c) 2015 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/>.
+ *
+ */
+
+#ifndef QCRYPTO_BLOCK_QCOWAES_H__
+#define QCRYPTO_BLOCK_QCOWAES_H__
+
+#include "crypto/blockpriv.h"
+
+extern const QCryptoBlockDriver qcrypto_block_driver_qcowaes;
+
+#endif /* QCRYPTO_BLOCK_QCOWAES_H__ */
diff --git a/crypto/block.c b/crypto/block.c
new file mode 100644
index 0000000..657f4a9
--- /dev/null
+++ b/crypto/block.c
@@ -0,0 +1,254 @@
+/*
+ * QEMU Crypto block device encryption
+ *
+ * Copyright (c) 2015 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 "crypto/blockpriv.h"
+#include "crypto/block-qcowaes.h"
+
+static const QCryptoBlockDriver *qcrypto_block_drivers[] = {
+ [Q_CRYPTO_BLOCK_FORMAT_QCOWAES] = &qcrypto_block_driver_qcowaes,
+};
+
+
+gboolean qcrypto_block_has_format(QCryptoBlockFormat format,
+ const uint8_t *buf,
+ size_t len)
+{
+ const QCryptoBlockDriver *driver;
+
+ if (format >= G_N_ELEMENTS(qcrypto_block_drivers) ||
+ !qcrypto_block_drivers[format]) {
+ return false;
+ }
+
+ driver = qcrypto_block_drivers[format];
+
+ return driver->has_format(buf, len);
+}
+
+
+QCryptoBlock *qcrypto_block_open(QCryptoBlockOpenOptions *options,
+ QCryptoBlockReadFunc readfunc,
+ void *opaque,
+ unsigned int flags,
+ Error **errp)
+{
+ QCryptoBlock *block = g_new0(QCryptoBlock, 1);
+
+ block->format = options->format;
+
+ if (options->format >= G_N_ELEMENTS(qcrypto_block_drivers) ||
+ !qcrypto_block_drivers[options->format]) {
+ error_setg(errp, "Unsupported block driver %d", options->format);
+ g_free(block);
+ return NULL;
+ }
+
+ block->driver = qcrypto_block_drivers[options->format];
+
+ if (block->driver->open(block, options, readfunc, opaque, flags, errp) <
0) {
+ g_free(block);
+ return NULL;
+ }
+
+ return block;
+}
+
+
+QCryptoBlock *qcrypto_block_create(QCryptoBlockCreateOptions *options,
+ QCryptoBlockInitFunc initfunc,
+ QCryptoBlockWriteFunc writefunc,
+ void *opaque,
+ Error **errp)
+{
+ QCryptoBlock *block = g_new0(QCryptoBlock, 1);
+
+ block->format = options->format;
+
+ if (options->format >= G_N_ELEMENTS(qcrypto_block_drivers) ||
+ !qcrypto_block_drivers[options->format]) {
+ error_setg(errp, "Unsupported block driver %d", options->format);
+ g_free(block);
+ return NULL;
+ }
+
+ block->driver = qcrypto_block_drivers[options->format];
+
+ if (block->driver->create(block, options, initfunc,
+ writefunc, opaque, errp) < 0) {
+ g_free(block);
+ return NULL;
+ }
+
+ return block;
+}
+
+
+int qcrypto_block_decrypt(QCryptoBlock *block,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp)
+{
+ return block->driver->decrypt(block, startsector, buf, len, errp);
+}
+
+
+int qcrypto_block_encrypt(QCryptoBlock *block,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp)
+{
+ return block->driver->encrypt(block, startsector, buf, len, errp);
+}
+
+
+QCryptoCipher *qcrypto_block_get_cipher(QCryptoBlock *block)
+{
+ return block->cipher;
+}
+
+
+QCryptoIVGen *qcrypto_block_get_ivgen(QCryptoBlock *block)
+{
+ return block->ivgen;
+}
+
+
+uint64_t qcrypto_block_get_payload_offset(QCryptoBlock *block)
+{
+ return block->payload_offset;
+}
+
+
+void qcrypto_block_free(QCryptoBlock *block)
+{
+ if (!block) {
+ return;
+ }
+
+ block->driver->cleanup(block);
+
+ g_free(block);
+}
+
+
+int qcrypto_block_decrypt_helper(QCryptoCipher *cipher,
+ size_t niv,
+ QCryptoIVGen *ivgen,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp)
+{
+ size_t nsectors = len / 512;
+ size_t i;
+ uint8_t *iv;
+ int ret = -1;
+
+ if (len % 512) {
+ error_setg(errp, "Length %zu must be a multiple of sector size",
+ len);
+ return -1;
+ }
+
+ iv = niv ? g_new0(uint8_t, niv) : NULL;
+
+ for (i = 0; i < nsectors; i++) {
+ if (niv) {
+ if (qcrypto_ivgen_calculate(ivgen,
+ startsector + i,
+ iv, niv,
+ errp) < 0) {
+ goto cleanup;
+ }
+
+ if (qcrypto_cipher_setiv(cipher,
+ iv, niv,
+ errp) < 0) {
+ goto cleanup;
+ }
+ }
+ if (qcrypto_cipher_decrypt(cipher,
+ buf + (i * 512),
+ buf + (i * 512),
+ 512,
+ errp) < 0) {
+ goto cleanup;
+ }
+ }
+
+ ret = 0;
+ cleanup:
+ g_free(iv);
+ return ret;
+}
+
+
+int qcrypto_block_encrypt_helper(QCryptoCipher *cipher,
+ size_t niv,
+ QCryptoIVGen *ivgen,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp)
+{
+ size_t nsectors = len / 512;
+ size_t i;
+ uint8_t *iv;
+ int ret = -1;
+
+ if (len % 512) {
+ error_setg(errp, "Length %zu must be a multiple of sector size",
+ len);
+ return -1;
+ }
+
+ iv = niv ? g_new0(uint8_t, niv) : NULL;
+
+ for (i = 0; i < nsectors; i++) {
+ if (niv) {
+ if (qcrypto_ivgen_calculate(ivgen,
+ startsector + i,
+ iv, niv,
+ errp) < 0) {
+ goto cleanup;
+ }
+
+ if (qcrypto_cipher_setiv(cipher,
+ iv, niv,
+ errp) < 0) {
+ goto cleanup;
+ }
+ }
+ if (qcrypto_cipher_encrypt(cipher,
+ buf + (i * 512),
+ buf + (i * 512),
+ 512,
+ errp) < 0) {
+ goto cleanup;
+ }
+ }
+
+ ret = 0;
+ cleanup:
+ g_free(iv);
+ return ret;
+}
diff --git a/crypto/blockpriv.h b/crypto/blockpriv.h
new file mode 100644
index 0000000..7ca42c5
--- /dev/null
+++ b/crypto/blockpriv.h
@@ -0,0 +1,89 @@
+/*
+ * QEMU Crypto block device encryption
+ *
+ * Copyright (c) 2015 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/>.
+ *
+ */
+
+#ifndef QCRYPTO_BLOCK_PRIV_H__
+#define QCRYPTO_BLOCK_PRIV_H__
+
+#include "crypto/block.h"
+
+typedef struct QCryptoBlockDriver QCryptoBlockDriver;
+
+struct QCryptoBlock {
+ QCryptoBlockFormat format;
+
+ const QCryptoBlockDriver *driver;
+ void *opaque;
+
+ QCryptoCipher *cipher;
+ QCryptoIVGen *ivgen;
+ size_t niv;
+ uint64_t payload_offset; /* In 512 byte sectors */
+};
+
+struct QCryptoBlockDriver {
+ int (*open)(QCryptoBlock *block,
+ QCryptoBlockOpenOptions *options,
+ QCryptoBlockReadFunc readfunc,
+ void *opaque,
+ unsigned int flags,
+ Error **errp);
+
+ int (*create)(QCryptoBlock *block,
+ QCryptoBlockCreateOptions *options,
+ QCryptoBlockInitFunc initfunc,
+ QCryptoBlockWriteFunc writefunc,
+ void *opaque,
+ Error **errp);
+
+ void (*cleanup)(QCryptoBlock *block);
+
+ int (*encrypt)(QCryptoBlock *block,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp);
+ int (*decrypt)(QCryptoBlock *block,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp);
+
+ gboolean (*has_format)(const uint8_t *buf,
+ size_t buflen);
+};
+
+
+int qcrypto_block_decrypt_helper(QCryptoCipher *cipher,
+ size_t niv,
+ QCryptoIVGen *ivgen,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp);
+
+int qcrypto_block_encrypt_helper(QCryptoCipher *cipher,
+ size_t niv,
+ QCryptoIVGen *ivgen,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp);
+
+#endif /* QCRYPTO_BLOCK_PRIV_H__ */
diff --git a/include/crypto/block.h b/include/crypto/block.h
new file mode 100644
index 0000000..e4834b3
--- /dev/null
+++ b/include/crypto/block.h
@@ -0,0 +1,222 @@
+/*
+ * QEMU Crypto block device encryption
+ *
+ * Copyright (c) 2015 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/>.
+ *
+ */
+
+#ifndef QCRYPTO_BLOCK_H__
+#define QCRYPTO_BLOCK_H__
+
+#include "crypto/cipher.h"
+#include "crypto/ivgen.h"
+
+typedef struct QCryptoBlock QCryptoBlock;
+
+/* See also QCryptoBlockFormat, QCryptoBlockCreateOptions
+ * and QCryptoBlockOpenOptions in qapi/crypto.json */
+
+typedef ssize_t (*QCryptoBlockReadFunc)(QCryptoBlock *block,
+ size_t offset,
+ uint8_t *buf,
+ size_t buflen,
+ Error **errp,
+ void *opaque);
+
+typedef ssize_t (*QCryptoBlockInitFunc)(QCryptoBlock *block,
+ size_t headerlen,
+ Error **errp,
+ void *opaque);
+
+typedef ssize_t (*QCryptoBlockWriteFunc)(QCryptoBlock *block,
+ size_t offset,
+ const uint8_t *buf,
+ size_t buflen,
+ Error **errp,
+ void *opaque);
+
+/**
+ * qcrypto_block_has_format:
+ * @format: the encryption format
+ * @buf: the data from head of the volume
+ * @len: the length of @buf in bytes
+ *
+ * Given @len bytes of data from the head of a storage volume
+ * in @buf, probe to determine if the volume has the encryption
+ * format specified in @format.
+ *
+ * Returns: true if the data in @buf matches @format
+ */
+gboolean qcrypto_block_has_format(QCryptoBlockFormat format,
+ const uint8_t *buf,
+ size_t buflen);
+
+typedef enum {
+ QCRYPTO_BLOCK_OPEN_NO_IO = (1 << 0),
+} QCryptoBlockOpenFlags;
+
+/**
+ * qcrypto_block_open:
+ * @options: the encryption options
+ * @readfunc: callback for reading data from the volume
+ * @opaque: data to pass to @readfunc
+ * @flags: bitmask of QCryptoBlockOpenFlags values
+ * @errp: pointer to an uninitialized error object
+ *
+ * Create a new block encryption object for an existing
+ * storage volume encrypted with format identified by
+ * the parameters in @options.
+ *
+ * This will use @readfunc to initialize the encryption
+ * context based on the volume header(s), extracting the
+ * master key(s) as required.
+ *
+ * If @flags contains QCRYPTO_BLOCK_OPEN_NO_IO then
+ * the open process will be optimized to skip any parts
+ * that are only required to perform I/O. In particular
+ * this would usually avoid the need to decrypt any
+ * master keys. The only thing that can be done with
+ * the resulting QCryptoBlock object would be to query
+ * metadata such as the payload offset. There will be
+ * no cipher or ivgen objects available.
+ *
+ * If any part of initializing the encryption context
+ * fails an error will be returned. This could be due
+ * to the volume being in the wrong format, an cipher
+ * or IV generator algorithm that is not supoported,
+ * or incorrect passphrases.
+ *
+ * Returns: a block encryption format, or NULL on error
+ */
+QCryptoBlock *qcrypto_block_open(QCryptoBlockOpenOptions *options,
+ QCryptoBlockReadFunc readfunc,
+ void *opaque,
+ unsigned int flags,
+ Error **errp);
+
+/**
+ * qcrypto_block_create:
+ * @format: the encryption format
+ * @keyid: ID of a QCryptoSecret with key for unlocking master key
+ * @initfunc: callback for initializing volume header
+ * @writefunc: callback for writing data to the volume header
+ * @opaque: data to pass to @initfunc & @writefunc
+ * @errp: pointer to an uninitialized error object
+ *
+ * Create a new block encryption object for initializing
+ * a storage volume to be encrypted with format identified
+ * by the parameters in @options.
+ *
+ * This method will allocate space for a new volume header
+ * using @initfunc and then write header data using @writefunc,
+ * generating new master keys, etc as required. Any existing
+ * data present on the volume will be irrevokably destroyed.
+ *
+ * If any part of initializing the encryption context
+ * fails an error will be returned. This could be due
+ * to the volume being in the wrong format, an cipher
+ * or IV generator algorithm that is not supoported,
+ * or incorrect passphrases.
+ *
+ * Returns: a block encryption format, or NULL on error
+ */
+QCryptoBlock *qcrypto_block_create(QCryptoBlockCreateOptions *options,
+ QCryptoBlockInitFunc initfunc,
+ QCryptoBlockWriteFunc writefunc,
+ void *opaque,
+ Error **errp);
+
+/**
+ * @qcrypto_block_decrypt:
+ * @block: the block encryption object
+ * @startsector: the sector from which @buf was read
+ * @buf: the buffer to decrypt
+ * @len: the length of @buf in bytes
+ * @errp: pointer to an uninitialized error object
+ *
+ * Decrypt @len bytes of cipher text in @buf, writing
+ * plain text back into @buf
+ *
+ * Returns 0 on success, -1 on failure
+ */
+int qcrypto_block_decrypt(QCryptoBlock *block,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp);
+
+/**
+ * @qcrypto_block_encrypt:
+ * @block: the block encryption object
+ * @startsector: the sector to which @buf will be written
+ * @buf: the buffer to decrypt
+ * @len: the length of @buf in bytes
+ * @errp: pointer to an uninitialized error object
+ *
+ * Encrypt @len bytes of plain text in @buf, writing
+ * cipher text back into @buf
+ *
+ * Returns 0 on success, -1 on failure
+ */
+int qcrypto_block_encrypt(QCryptoBlock *block,
+ uint64_t startsector,
+ uint8_t *buf,
+ size_t len,
+ Error **errp);
+
+/**
+ * qcrypto_block_get_cipher:
+ * @block: the block encryption object
+ *
+ * Get the cipher to use for payload encryption
+ *
+ * Returns: the cipher object
+ */
+QCryptoCipher *qcrypto_block_get_cipher(QCryptoBlock *block);
+
+/**
+ * qcrypto_block_get_ivgen:
+ * @block: the block encryption object
+ *
+ * Get the initialization vector generator to use for
+ * payload encryption
+ *
+ * Returns: the IV generator object
+ */
+QCryptoIVGen *qcrypto_block_get_ivgen(QCryptoBlock *block);
+
+/**
+ * qcrypto_block_get_payload_offset:
+ * @block: the block encryption object
+ *
+ * Get the offset to the payload indicated by the
+ * encryption header. The offset is measured in
+ * 512 byte sectors
+ *
+ * Returns: the payload offset in sectors.
+ */
+uint64_t qcrypto_block_get_payload_offset(QCryptoBlock *block);
+
+/**
+ * qcrypto_block_free:
+ * @block: the block encryption object
+ *
+ * Release all resources associated with the encryption
+ * object
+ */
+void qcrypto_block_free(QCryptoBlock *block);
+
+#endif /* QCRYPTO_BLOCK_H__ */
diff --git a/qapi/crypto.json b/qapi/crypto.json
index 48946b0..07b9b46 100644
--- a/qapi/crypto.json
+++ b/qapi/crypto.json
@@ -94,3 +94,68 @@
{ 'enum': 'QCryptoIVGenAlgorithm',
'prefix': 'QCRYPTO_IVGEN_ALG',
'data': ['plain', 'plain64', 'essiv']}
+
+##
+# QCryptoBlockFormat:
+#
+# The supported full disk encryption formats
+#
+# @qcowaes: QCow/QCow2 built-in AES-CBC encryption. Do not use
+#
+# Since: 2.6
+##
+{ 'enum': 'QCryptoBlockFormat',
+# 'prefix': 'QCRYPTO_BLOCK_FORMAT',
+ 'data': ['qcowaes']}
+
+##
+# QCryptoBlockOptionsBase:
+#
+# The common options that apply to all full disk
+# encryption formats
+#
+# @format: the encryption format
+#
+# Since: 2.6
+##
+{ 'struct': 'QCryptoBlockOptionsBase',
+ 'data': { 'format': 'QCryptoBlockFormat' }}
+
+##
+# QCryptoBlockOptionsQCowAES:
+#
+# The options that apply to QCow AES encryption format
+#
+# @key-id: the ID of a QCryptoSecret object providing the decryption key
+#
+# Since: 2.6
+##
+{ 'struct': 'QCryptoBlockOptionsQCowAES',
+ 'data': { '*key-id': 'str' }}
+
+##
+# QCryptoBlockOpenOptions:
+#
+# The options that are available for all encryption formats
+# when opening an existing volume
+#
+# Since: 2.6
+##
+{ 'union': 'QCryptoBlockOpenOptions',
+ 'base': 'QCryptoBlockOptionsBase',
+ 'discriminator': 'format',
+ 'data': { 'qcowaes': 'QCryptoBlockOptionsQCowAES' } }
+
+
+##
+# QCryptoBlockCreateOptions:
+#
+# The options that are available for all encryption formats
+# when initializing a new volume
+#
+# Since: 2.6
+##
+{ 'union': 'QCryptoBlockCreateOptions',
+ 'base': 'QCryptoBlockOptionsBase',
+ 'discriminator': 'format',
+ 'data': { 'qcowaes': 'QCryptoBlockOptionsQCowAES' } }
--
2.5.0