 43cbd06df2
			
		
	
	
		43cbd06df2
		
	
	
	
	
		
			
			This will be used first to implement luks keyslot management. block_crypto_amend_opts_init will be used to convert qemu-img cmdline to QCryptoBlockAmendOptions Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20200608094030.670121-2-mlevitsk@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
		
			
				
	
	
		
			318 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			318 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * QEMU Crypto block device encryption
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|  *
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|  * Copyright (c) 2015-2016 Red Hat, Inc.
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|  *
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|  * This library is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * This library is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
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|  *
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|  */
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| 
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| #ifndef QCRYPTO_BLOCK_H
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| #define QCRYPTO_BLOCK_H
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| 
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| #include "crypto/cipher.h"
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| #include "crypto/ivgen.h"
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| 
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| typedef struct QCryptoBlock QCryptoBlock;
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| 
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| /* See also QCryptoBlockFormat, QCryptoBlockCreateOptions
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|  * and QCryptoBlockOpenOptions in qapi/crypto.json */
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| 
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| typedef ssize_t (*QCryptoBlockReadFunc)(QCryptoBlock *block,
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|                                         size_t offset,
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|                                         uint8_t *buf,
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|                                         size_t buflen,
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|                                         void *opaque,
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|                                         Error **errp);
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| 
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| typedef ssize_t (*QCryptoBlockInitFunc)(QCryptoBlock *block,
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|                                         size_t headerlen,
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|                                         void *opaque,
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|                                         Error **errp);
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| 
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| typedef ssize_t (*QCryptoBlockWriteFunc)(QCryptoBlock *block,
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|                                          size_t offset,
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|                                          const uint8_t *buf,
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|                                          size_t buflen,
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|                                          void *opaque,
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|                                          Error **errp);
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| 
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| /**
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|  * qcrypto_block_has_format:
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|  * @format: the encryption format
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|  * @buf: the data from head of the volume
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|  * @len: the length of @buf in bytes
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|  *
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|  * Given @len bytes of data from the head of a storage volume
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|  * in @buf, probe to determine if the volume has the encryption
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|  * format specified in @format.
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|  *
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|  * Returns: true if the data in @buf matches @format
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|  */
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| bool qcrypto_block_has_format(QCryptoBlockFormat format,
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|                               const uint8_t *buf,
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|                               size_t buflen);
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| 
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| typedef enum {
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|     QCRYPTO_BLOCK_OPEN_NO_IO = (1 << 0),
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| } QCryptoBlockOpenFlags;
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| 
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| /**
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|  * qcrypto_block_open:
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|  * @options: the encryption options
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|  * @optprefix: name prefix for options
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|  * @readfunc: callback for reading data from the volume
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|  * @opaque: data to pass to @readfunc
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|  * @flags: bitmask of QCryptoBlockOpenFlags values
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|  * @n_threads: allow concurrent I/O from up to @n_threads threads
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Create a new block encryption object for an existing
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|  * storage volume encrypted with format identified by
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|  * the parameters in @options.
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|  *
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|  * This will use @readfunc to initialize the encryption
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|  * context based on the volume header(s), extracting the
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|  * master key(s) as required.
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|  *
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|  * If @flags contains QCRYPTO_BLOCK_OPEN_NO_IO then
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|  * the open process will be optimized to skip any parts
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|  * that are only required to perform I/O. In particular
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|  * this would usually avoid the need to decrypt any
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|  * master keys. The only thing that can be done with
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|  * the resulting QCryptoBlock object would be to query
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|  * metadata such as the payload offset. There will be
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|  * no cipher or ivgen objects available.
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|  *
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|  * If any part of initializing the encryption context
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|  * fails an error will be returned. This could be due
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|  * to the volume being in the wrong format, a cipher
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|  * or IV generator algorithm that is not supported,
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|  * or incorrect passphrases.
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|  *
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|  * Returns: a block encryption format, or NULL on error
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|  */
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| QCryptoBlock *qcrypto_block_open(QCryptoBlockOpenOptions *options,
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|                                  const char *optprefix,
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|                                  QCryptoBlockReadFunc readfunc,
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|                                  void *opaque,
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|                                  unsigned int flags,
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|                                  size_t n_threads,
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|                                  Error **errp);
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| 
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| /**
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|  * qcrypto_block_create:
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|  * @options: the encryption options
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|  * @optprefix: name prefix for options
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|  * @initfunc: callback for initializing volume header
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|  * @writefunc: callback for writing data to the volume header
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|  * @opaque: data to pass to @initfunc and @writefunc
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Create a new block encryption object for initializing
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|  * a storage volume to be encrypted with format identified
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|  * by the parameters in @options.
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|  *
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|  * This method will allocate space for a new volume header
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|  * using @initfunc and then write header data using @writefunc,
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|  * generating new master keys, etc as required. Any existing
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|  * data present on the volume will be irrevocably destroyed.
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|  *
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|  * If any part of initializing the encryption context
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|  * fails an error will be returned. This could be due
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|  * to the volume being in the wrong format, a cipher
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|  * or IV generator algorithm that is not supported,
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|  * or incorrect passphrases.
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|  *
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|  * Returns: a block encryption format, or NULL on error
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|  */
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| QCryptoBlock *qcrypto_block_create(QCryptoBlockCreateOptions *options,
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|                                    const char *optprefix,
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|                                    QCryptoBlockInitFunc initfunc,
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|                                    QCryptoBlockWriteFunc writefunc,
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|                                    void *opaque,
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|                                    Error **errp);
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| 
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| /**
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|  * qcrypto_block_amend_options:
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|  * @block: the block encryption object
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|  *
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|  * @readfunc: callback for reading data from the volume header
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|  * @writefunc: callback for writing data to the volume header
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|  * @opaque: data to pass to @readfunc and @writefunc
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|  * @options: the new/amended encryption options
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|  * @force: hint for the driver to allow unsafe operation
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|  * @errp: error pointer
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|  *
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|  * Changes the crypto options of the encryption format
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|  *
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|  */
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| int qcrypto_block_amend_options(QCryptoBlock *block,
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|                                 QCryptoBlockReadFunc readfunc,
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|                                 QCryptoBlockWriteFunc writefunc,
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|                                 void *opaque,
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|                                 QCryptoBlockAmendOptions *options,
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|                                 bool force,
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|                                 Error **errp);
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| 
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| 
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| /**
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|  * qcrypto_block_calculate_payload_offset:
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|  * @create_opts: the encryption options
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|  * @optprefix: name prefix for options
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|  * @len: output for number of header bytes before payload
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Calculate the number of header bytes before the payload in an encrypted
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|  * storage volume.  The header is an area before the payload that is reserved
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|  * for encryption metadata.
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|  *
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|  * Returns: true on success, false on error
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|  */
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| bool
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| qcrypto_block_calculate_payload_offset(QCryptoBlockCreateOptions *create_opts,
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|                                        const char *optprefix,
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|                                        size_t *len,
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|                                        Error **errp);
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| 
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| 
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| /**
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|  * qcrypto_block_get_info:
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|  * @block: the block encryption object
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Get information about the configuration options for the
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|  * block encryption object. This includes details such as
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|  * the cipher algorithms, modes, and initialization vector
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|  * generators.
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|  *
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|  * Returns: a block encryption info object, or NULL on error
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|  */
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| QCryptoBlockInfo *qcrypto_block_get_info(QCryptoBlock *block,
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|                                          Error **errp);
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| 
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| /**
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|  * @qcrypto_block_decrypt:
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|  * @block: the block encryption object
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|  * @offset: the position at which @iov was read
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|  * @buf: the buffer to decrypt
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|  * @len: the length of @buf in bytes
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Decrypt @len bytes of cipher text in @buf, writing
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|  * plain text back into @buf. @len and @offset must be
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|  * a multiple of the encryption format sector size.
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|  *
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|  * Returns 0 on success, -1 on failure
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|  */
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| int qcrypto_block_decrypt(QCryptoBlock *block,
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|                           uint64_t offset,
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|                           uint8_t *buf,
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|                           size_t len,
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|                           Error **errp);
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| 
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| /**
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|  * @qcrypto_block_encrypt:
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|  * @block: the block encryption object
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|  * @offset: the position at which @iov will be written
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|  * @buf: the buffer to decrypt
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|  * @len: the length of @buf in bytes
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|  * @errp: pointer to a NULL-initialized error object
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|  *
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|  * Encrypt @len bytes of plain text in @buf, writing
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|  * cipher text back into @buf. @len and @offset must be
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|  * a multiple of the encryption format sector size.
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|  *
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|  * Returns 0 on success, -1 on failure
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|  */
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| int qcrypto_block_encrypt(QCryptoBlock *block,
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|                           uint64_t offset,
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|                           uint8_t *buf,
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|                           size_t len,
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|                           Error **errp);
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| 
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| /**
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|  * qcrypto_block_get_cipher:
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|  * @block: the block encryption object
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|  *
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|  * Get the cipher to use for payload encryption
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|  *
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|  * Returns: the cipher object
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|  */
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| QCryptoCipher *qcrypto_block_get_cipher(QCryptoBlock *block);
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| 
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| /**
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|  * qcrypto_block_get_ivgen:
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|  * @block: the block encryption object
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|  *
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|  * Get the initialization vector generator to use for
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|  * payload encryption
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|  *
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|  * Returns: the IV generator object
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|  */
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| QCryptoIVGen *qcrypto_block_get_ivgen(QCryptoBlock *block);
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| 
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| 
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| /**
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|  * qcrypto_block_get_kdf_hash:
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|  * @block: the block encryption object
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|  *
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|  * Get the hash algorithm used with the key derivation
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|  * function
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|  *
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|  * Returns: the hash algorithm
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|  */
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| QCryptoHashAlgorithm qcrypto_block_get_kdf_hash(QCryptoBlock *block);
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| 
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| /**
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|  * qcrypto_block_get_payload_offset:
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|  * @block: the block encryption object
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|  *
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|  * Get the offset to the payload indicated by the
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|  * encryption header, in bytes.
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|  *
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|  * Returns: the payload offset in bytes
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|  */
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| uint64_t qcrypto_block_get_payload_offset(QCryptoBlock *block);
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| 
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| /**
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|  * qcrypto_block_get_sector_size:
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|  * @block: the block encryption object
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|  *
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|  * Get the size of sectors used for payload encryption. A new
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|  * IV is used at the start of each sector. The encryption
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|  * sector size is not required to match the sector size of the
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|  * underlying storage. For example LUKS will always use a 512
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|  * byte sector size, even if the volume is on a disk with 4k
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|  * sectors.
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|  *
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|  * Returns: the sector in bytes
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|  */
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| uint64_t qcrypto_block_get_sector_size(QCryptoBlock *block);
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| 
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| /**
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|  * qcrypto_block_free:
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|  * @block: the block encryption object
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|  *
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|  * Release all resources associated with the encryption
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|  * object
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|  */
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| void qcrypto_block_free(QCryptoBlock *block);
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| 
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| G_DEFINE_AUTOPTR_CLEANUP_FUNC(QCryptoBlock, qcrypto_block_free)
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| G_DEFINE_AUTOPTR_CLEANUP_FUNC(QCryptoBlockCreateOptions,
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|                               qapi_free_QCryptoBlockCreateOptions)
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| 
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| #endif /* QCRYPTO_BLOCK_H */
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