| /* |
| * QEMU Crypto block device encryption |
| * |
| * 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/>. |
| * |
| */ |
| |
| #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 |
| */ |
| bool 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 a NULL-initialized 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, a cipher |
| * or IV generator algorithm that is not supported, |
| * 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 |
| * @initfunc: callback for initializing volume header |
| * @writefunc: callback for writing data to the volume header |
| * @opaque: data to pass to @initfunc and @writefunc |
| * @errp: pointer to a NULL-initialized 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 irrevocably 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, a cipher |
| * or IV generator algorithm that is not supported, |
| * 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 a NULL-initialized 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 a NULL-initialized 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_kdf_hash: |
| * @block: the block encryption object |
| * |
| * Get the hash algorithm used with the key derivation |
| * function |
| * |
| * Returns: the hash algorithm |
| */ |
| QCryptoHashAlgorithm qcrypto_block_get_kdf_hash(QCryptoBlock *block); |
| |
| /** |
| * qcrypto_block_get_payload_offset: |
| * @block: the block encryption object |
| * |
| * Get the offset to the payload indicated by the |
| * encryption header, in bytes. |
| * |
| * Returns: the payload offset in bytes |
| */ |
| 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__ */ |
