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kcapi.h
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kcapi.h
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/*
* Copyright (C) 2015 - 2024, Stephan Mueller <smueller@chronox.de>
*
* License: see COPYING file in root directory
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
* WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
#ifndef KCAPI_H
#define KCAPI_H
#include <stdint.h>
#include <sys/uio.h>
#ifdef __cplusplus
extern "C"
{
#endif
#define DSO_DEPRECATED(x) \
__attribute__ ((deprecated ("API deprecated with library version " x)))
/*
* Flags for the encrypt / decrypt operations
*
* @KCAPI_ACCESS_HEURISTIC Allow the libkcapi heuristic to determine the
* optimal kernel access type
* @KCAPI_ACCESS_VMSPLICE Require libkcapi to always use the vmsplice zero
* copy kernel interface
* @KCAPI_ACCESS_SENDMSG Require libkcapi to always use the sendmsg kernel
* interface
*/
#define KCAPI_ACCESS_HEURISTIC 0x0
#define KCAPI_ACCESS_VMSPLICE 0x1
#define KCAPI_ACCESS_SENDMSG 0x2
/*
* Flags for initializing a cipher handle
*
* @KCAPI_INIT_AIO Handle uses AIO kernel interface if available
*/
#define KCAPI_INIT_AIO (1<<0)
/*
* Opaque cipher handle
*/
struct kcapi_handle;
/**
* DOC: Symmetric Cipher API
*
* API function calls used to invoke symmetric ciphers.
*/
/**
* kcapi_handle_reinit() - re-initialize a new kernel interface
*
* @newhandle: [out] cipher handle filled during the call
* @existing: [in] existing cipher handle from which a new handle shall be
* re-initialized
* @flags: [in] flags specifying the type of cipher handle
*
* The kernel crypto API interface operates with two types of file descriptors,
* the TFM file descriptor and the OP file descriptor.
*
* The TFM file descriptor receives the cipher-operation static information:
* the key, and the AEAD tag size.
*
* The OP file descriptor receives the volatile data, such as the plaintext /
* ciphertext, the IV, or the AEAD AD size.
*
* The kernel crypto API AF_ALG interface supports the concept that one TFM
* file descriptor can operate with multiple OP file descriptors. The different
* OP file descriptors can perform completely separate cipher operations
* using the same key which can execute in parallel. The parallel execution
* can be performed in the same or different process threads.
*
* kcapi_handle_reinit() function allows the allocation of a new cipher handle
* with a new OP file descriptor but using the same TFM file descriptor. To
* obtain a reference to the TFM file descriptor, an @existing cipher handle
* is used as source. kcapi_handle_reinit() can be invoked multiple times.
* Each resulting cipher handle must be deallocated with kcapi_cipher_destroy().
* The deallocation ensures that the TFM resource is only released if the
* last handle using this TFM resource is released.
*
* @return 0 upon success;
* -EINVAL - accept syscall failed
* -ENOMEM - cipher handle cannot be allocated
*/
int kcapi_handle_reinit(struct kcapi_handle **newhandle,
struct kcapi_handle *existing, uint32_t flags);
/**
* kcapi_cipher_init() - initialize cipher handle
*
* @handle: [out] cipher handle filled during the call
* @ciphername: [in] kernel crypto API cipher name as specified in
* /proc/crypto
* @flags: [in] flags specifying the type of cipher handle
*
* This function provides the initialization of a symmetric cipher handle and
* establishes the connection to the kernel.
*
* On success, a pointer to kcapi_handle object is returned in *handle.
* Function kcapi_cipher_destroy() should be called afterwards to free
* resources.
*
* @return 0 upon success;
* -ENOENT - algorithm not available;
* -EOPNOTSUPP - AF_ALG family not available;
* -EINVAL - accept syscall failed
* -ENOMEM - cipher handle cannot be allocated
*/
int kcapi_cipher_init(struct kcapi_handle **handle, const char *ciphername,
uint32_t flags);
/**
* kcapi_cipher_destroy() - close the cipher handle and release resources
*
* @handle: [in] cipher handle to release
*/
void kcapi_cipher_destroy(struct kcapi_handle *handle);
/**
* kcapi_cipher_setkey() - set the key for the cipher handle
*
* @handle: [in] cipher handle
* @key: [in] key buffer
* @keylen: [in] length of key buffer
*
* With this function, the caller sets the key for subsequent encryption or
* decryption operations.
*
* After the caller provided the key, the caller may securely destroy the key
* as it is now maintained by the kernel.
*
* @return 0 upon success (in case of an akcipher handle, a positive integer
* is returned that denominates the maximum output size of the
* cryptographic operation -- this value must be used as the size
* of the output buffer for one cryptographic operation);
* a negative errno-style error code if an error occurred
*/
int kcapi_cipher_setkey(struct kcapi_handle *handle,
const uint8_t *key, uint32_t keylen);
/**
* kcapi_cipher_encrypt() - encrypt data (synchronous one shot)
*
* @handle: [in] cipher handle
* @in: [in] plaintext data buffer
* @inlen: [in] length of in buffer
* @iv: [in] IV to be used for cipher operation
* @out: [out] ciphertext data buffer
* @outlen: [in] length of out buffer
* @access: [in] kernel access type (KCAPI_ACCESS_HEURISTIC - use internal
* heuristic for fastest kernel access; KCAPI_ACCESS_VMSPLICE - use
* vmsplice access; KCAPI_ACCESS_SENDMSG - sendmsg access)
*
* It is perfectly legal to use the same buffer as the plaintext and
* ciphertext pointers. That would mean that after the encryption operation,
* the plaintext is overwritten with the ciphertext.
*
* The memory should be aligned at the page boundary using
* posix_memalign(sysconf(_SC_PAGESIZE)), If it is not aligned at the page
* boundary, the vmsplice call may not send all data to the kernel.
*
* The IV buffer must be exactly kcapi_cipher_ivsize() bytes in size.
*
* @return number of bytes encrypted upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_encrypt(struct kcapi_handle *handle,
const uint8_t *in, size_t inlen,
const uint8_t *iv,
uint8_t *out, size_t outlen, int access);
/**
* kcapi_cipher_encrypt_aio() - encrypt data (asynchronous one shot)
*
* @handle: [in] cipher handle
* @iniov: [in] head of scatter-gather list array holding the plaintext
* @outiov: [out] head of scatter-gather list of the destination buffers filled
* with ciphertext
* @iovlen: [in] number of scatter-gather list entries
* @iv: [in] IV to be used for cipher operation
* @access: [in] kernel access type (KCAPI_ACCESS_HEURISTIC - use internal
* heuristic for fastest kernel access; KCAPI_ACCESS_VMSPLICE - use
* vmsplice access; KCAPI_ACCESS_SENDMSG - sendmsg access)
*
* The individual scatter-gather list entries are processed with
* separate invocations of the the given cipher.
*
* The memory should be aligned at the page boundary using
* posix_memalign(sysconf(_SC_PAGESIZE)), If it is not aligned at the page
* boundary, the vmsplice call may not send all data to the kernel.
*
* The IV buffer must be exactly kcapi_cipher_ivsize() bytes in size.
*
* @return number of bytes encrypted upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_encrypt_aio(struct kcapi_handle *handle,
struct iovec *iniov, struct iovec *outiov,
size_t iovlen, const uint8_t *iv,
int access);
/**
* kcapi_cipher_decrypt() - decrypt data (synchronous one shot)
*
* @handle: [in] cipher handle
* @in: [in] ciphertext data buffer
* @inlen: [in] length of in buffer
* @iv: [in] IV to be used for cipher operation
* @out: [out] plaintext data buffer
* @outlen: [in] length of out bufferS
* @access: [in] kernel access type (KCAPI_ACCESS_HEURISTIC - use internal
* heuristic for fastest kernel access; KCAPI_ACCESS_VMSPLICE - use
* vmsplice access; KCAPI_ACCESS_SENDMSG - sendmsg access)
*
* It is perfectly legal to use the same buffer as the plaintext and
* ciphertext pointers. That would mean that after the encryption operation,
* the ciphertext is overwritten with the plaintext.
*
* The memory should be aligned at the page boundary using
* posix_memalign(sysconf(_SC_PAGESIZE)), If it is not aligned at the page
* boundary, the vmsplice call may not send all data to the kernel.
*
* The IV buffer must be exactly kcapi_cipher_ivsize() bytes in size.
*
* @return number of bytes decrypted upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_decrypt(struct kcapi_handle *handle,
const uint8_t *in, size_t inlen,
const uint8_t *iv,
uint8_t *out, size_t outlen, int access);
/**
* kcapi_cipher_decrypt_aio() - decrypt data (asynchronous one shot)
*
* @handle: [in] cipher handle
* @iniov: [in] head of scatter-gather list array holding the ciphertext
* @outiov: [out] head of scatter-gather list with the destination buffers for
* the plaintext
* @iovlen: [in] number of scatter-gather list entries
* @iv: [in] IV to be used for cipher operation
* @access: [in] kernel access type (KCAPI_ACCESS_HEURISTIC - use internal
* heuristic for fastest kernel access; KCAPI_ACCESS_VMSPLICE - use
* vmsplice access; KCAPI_ACCESS_SENDMSG - sendmsg access)
*
* The individual scatter-gather list entries are processed with
* separate invocations of the the given cipher.
*
* The memory should be aligned at the page boundary using
* posix_memalign(sysconf(_SC_PAGESIZE)), If it is not aligned at the page
* boundary, the vmsplice call may not send all data to the kernel.
*
* The IV buffer must be exactly kcapi_cipher_ivsize() bytes in size.
*
* @return number of bytes decrypted upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_decrypt_aio(struct kcapi_handle *handle,
struct iovec *iniov, struct iovec *outiov,
size_t iovlen, const uint8_t *iv,
int access);
/**
* kcapi_cipher_stream_init_enc() - start an encryption operation (stream)
*
* @handle: [in] cipher handle
* @iv: [in] IV to be used for cipher operation
* @iov: [in] scatter/gather list with data to be encrypted. This is
* the pointer to the first iov entry if an array of iov
* entries is supplied. See sendmsg(2) for details on how iov is
* to be used. This pointer may be NULL if no data to be encrypted
* is available at the point of the call.
* @iovlen: [in] number of scatter/gather list elements. If iov
* is NULL, this value must be zero.
*
* A stream encryption operation is started with this call. Multiple
* successive kcapi_cipher_stream_update() function calls can be invoked to
* send more plaintext data to be encrypted. The kernel buffers the input
* until kcapi_cipher_stream_op() picks up the encrypted data. Once plaintext
* is encrypted during the kcapi_cipher_stream_op() it is removed from the
* kernel buffer.
*
* The function calls of kcapi_cipher_stream_update() and
* kcapi_cipher_stream_op() can be mixed, even by multiple threads of an
* application.
*
* The IV buffer must be exactly kcapi_cipher_ivsize() bytes in size.
*
* @return number of bytes sent to the kernel upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_stream_init_enc(struct kcapi_handle *handle,
const uint8_t *iv,
struct iovec *iov, size_t iovlen);
/**
* kcapi_cipher_stream_init_dec() - start a decryption operation (stream)
*
* @handle: [in] cipher handle
* @iv: [in] IV to be used for cipher operation
* @iov: [in] scatter/gather list with data to be encrypted. This is
* the pointer to the first iov entry if an array of iov
* entries is supplied. See sendmsg(2) for details on how iov is
* to be used. This pointer may be NULL if no data to be encrypted
* is available at the point of the call.
* @iovlen: [in] number of scatter/gather list elements. If iov
* is NULL, this value must be zero.
*
* A stream decryption operation is started with this call. Multiple
* successive kcapi_cipher_stream_update() function calls can be invoked to
* send more ciphertext data to be decrypted. The kernel buffers the input
* until kcapi_cipher_stream_op() picks up the decrypted data. Once ciphertext
* is decrypted during the kcapi_cipher_stream_op() it is removed from the
* kernel buffer.
*
* The function calls of kcapi_cipher_stream_update() and
* kcapi_cipher_stream_op() can be mixed, even by multiple threads of an
* application.
*
* The IV buffer must be exactly kcapi_cipher_ivsize() bytes in size.
*
* @return number of bytes sent to the kernel upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_stream_init_dec(struct kcapi_handle *handle,
const uint8_t *iv,
struct iovec *iov, size_t iovlen);
/**
* kcapi_cipher_stream_update() - send more data for processing (stream)
*
* @handle: [in] cipher handle
* @iov: [in] scatter/gather list with data to be processed by the
* cipher operation.
* @iovlen: [in] number of scatter/gather list elements.
*
* Using this function call, more plaintext for encryption or ciphertext for
* decryption can be submitted to the kernel.
*
* This function may cause the caller to sleep if the kernel buffer holding
* the data is getting full. The process will be woken up once more buffer
* space becomes available by calling kcapi_cipher_stream_op().
*
* Note: with the separate API calls of kcapi_cipher_stream_update() and
* kcapi_cipher_stream_op() a multi-threaded application can be implemented
* where one thread sends data to be processed and one thread picks up data
* processed by the cipher operation.
*
* IMPORTANT NOTE: The kernel will only process
* sysconf(_SC_PAGESIZE) * ALG_MAX_PAGES at one time. If your input data is
* larger than this threshold, you MUST segment it into chunks of at most
* sysconf(_SC_PAGESIZE) * ALG_MAX_PAGES and invoke the
* kcapi_cipher_stream_update() on that segment followed by
* kcapi_cipher_stream_op() before the next chunk is processed. If this
* rule is not obeyed, the thread invoking kcapi_cipher_stream_update()
* will be put to sleep until another thread invokes kcapi_cipher_stream_op().
*
* WARNING: The memory referenced by @iov is not accessed by the kernel
* during this call. The memory is first accessed when kcapi_cipher_stream_op()
* is called. Thus, you MUST make sure that the referenced memory is still
* present at the time kcapi_cipher_stream_op() is called.
*
* @return number of bytes sent to the kernel upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_stream_update(struct kcapi_handle *handle,
struct iovec *iov, size_t iovlen);
/**
* kcapi_cipher_stream_update_last() - send last data for processing (stream)
*
* @handle: [in] cipher handle
* @iov: [in] scatter/gather list with data to be processed by the cipher
* operation.
* @iovlen: [in] number of scatter/gather list elements.
*
* Using this function call, more plaintext for encryption or ciphertext for
* decryption can be submitted to the kernel.
*
* This call is identical to the kcapi_cipher_stream_update() call with the
* exception that it marks the last data buffer before the cipher operation
* is triggered. This is call is important for stream ciphers like CTR or CTS
* mode when providing the last block. It is permissible to provide a zero
* buffer if all data including the last block is already provided by
* kcapi_cipher_stream_update.
*
* WARNING: If this call is not made for stream ciphers with input data
* that is not a multiple of the block size of the block cipher, the kernel
* will not return the last block that contains less data than the block
* size of the block cipher. For example, sending 257 bytes of data to be
* encrypted with ctr(aes), the kernel will return only 256 bytes without
* this call.
*
* @return number of bytes sent to the kernel upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_stream_update_last(struct kcapi_handle *handle,
struct iovec *iov, size_t iovlen);
/**
* kcapi_cipher_stream_op() - obtain processed data (stream)
*
* @handle: [in] cipher handle
* @iov: [out] scatter/gather list pointing to buffers to be filled with
* the resulting data from a cipher operation.
* @iovlen: [in] number of scatter/gather list elements.
*
* This call can be called interleaved with kcapi_cipher_stream_update() to
* fetch the processed data.
*
* This function may cause the caller to sleep if the kernel buffer holding
* the data is empty. The process will be woken up once more data is sent
* by calling kcapi_cipher_stream_update().
*
* Note, when supplying buffers that are not multiple of block size, the buffers
* will only be filled up to the maximum number of full block sizes that fit
* into the buffer.
*
* The kernel supports multithreaded applications where one or more threads
* send data via the kcapi_cipher_stream_update() function and another thread
* collects the processed data via kcapi_cipher_stream_op. The kernel, however,
* will return data via kcapi_cipher_stream_op() as soon as it has some data
* available. For example, one thread sends 1000 bytes to be encrypted and
* another thread already waits for the ciphertext. The kernel may send only,
* say, 500 bytes back to the waiting process during one
* kcapi_cipher_stream_op() call. In a subsequent calls to
* kcapi_cipher_stream_op() more ciphertext is returned. This implies that when
* the receiving thread shall collect all data there is,
* kcapi_cipher_stream_op() must be called in a loop until all data is received.
*
* @return number of bytes obtained from the kernel upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_stream_op(struct kcapi_handle *handle,
struct iovec *iov, size_t iovlen);
/**
* kcapi_cipher_enc_aes_cbc - Convenience function for AES CBC encryption
*
* @key: [in] key buffer
* @keylen: [in] length of key buffer
* @in: [in] plaintext data buffer
* @inlen: [in] length of in buffer
* @iv: [in] IV to be used for cipher operation
* @out: [out] ciphertext data buffer
* @outlen: [in] length of out buffer
*
* The convenience function performs an AES CBC encryption operation
* using the provided key, the given input buffer and the given IV.
* The output is stored in the out buffer.
*
* Note, AES CBC requires an input data that is a multiple of 16 bytes.
* If you have data that is not guaranteed to be multiples of 16 bytes, either
* add zero bytes at the end of the buffer to pad it up to a multiple of 16
* bytes. Otherwise, the CTR mode encryption operation may be usable.
*
* The output buffer must be at least as large as the input buffer.
*
* The IV must be exactly 16 bytes in size.
*
* The AES type (AES-128, AES-192 or AES-256) is determined by the size
* of the given key. If the key is 16 bytes long, AES-128 is used. A 24 byte
* key implies AES-192 and a 32 byte key implies AES-256.
*
* @return number of bytes generated upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_enc_aes_cbc(const uint8_t *key, uint32_t keylen,
const uint8_t *in, size_t inlen,
const uint8_t *iv,
uint8_t *out, size_t outlen);
/**
* kcapi_cipher_dec_aes_cbc - Convenience function for AES CBC decryption
*
* @key: [in] key buffer
* @keylen: [in] length of key buffer
* @in: [in] ciphertext data buffer
* @inlen: [in] length of in buffer
* @iv: [in] IV to be used for cipher operation
* @out: [out] plaintext data buffer
* @outlen: [in] length of out buffer
*
* The convenience function performs an AES CBC decryption operation
* using the provided key, the given input buffer and the given IV.
* The output is stored in the out buffer.
*
* Note, AES CBC requires an input data that is a multiple of 16 bytes.
* If you have data that is not guaranteed to be multiples of 16 bytes, either
* add zero bytes at the end of the buffer to pad it up to a multiple of 16
* bytes. Otherwise, the CTR mode encryption operation may be usable.
*
* The output buffer must be at least as large as the input buffer.
*
* The IV must be exactly 16 bytes in size.
*
* The AES type (AES-128, AES-192 or AES-256) is determined by the size
* of the given key. If the key is 16 bytes long, AES-128 is used. A 24 byte
* key implies AES-192 and a 32 byte key implies AES-256.
*
* @return number of bytes generated upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_dec_aes_cbc(const uint8_t *key, uint32_t keylen,
const uint8_t *in, size_t inlen,
const uint8_t *iv,
uint8_t *out, size_t outlen);
/**
* kcapi_cipher_enc_aes_ctr - Convenience function for AES CTR encryption
*
* @key: [in] key buffer
* @keylen: [in] length of key buffer
* @in: [in] plaintext data buffer
* @inlen: [in] length of in buffer
* @ctr: [in] start counter value to be used for cipher operation
* @out: [out] ciphertext data buffer
* @outlen: [in] length of out buffer
*
* The convenience function performs an AES counter mode encryption operation
* using the provided key, the given input buffer and the given IV.
* The output is stored in the out buffer.
*
* The input buffer can be of arbitrary length.
*
* The output buffer must be at least as large as the input buffer.
*
* The start counter can contain all zeros (not a NULL buffer!) and must be
* exactly 16 bytes in size.
*
* The AES type (AES-128, AES-192 or AES-256) is determined by the size
* of the given key. If the key is 16 bytes long, AES-128 is used. A 24 byte
* key implies AES-192 and a 32 byte key implies AES-256.
*
* @return number of bytes generated upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_enc_aes_ctr(const uint8_t *key, uint32_t keylen,
const uint8_t *in, size_t inlen,
const uint8_t *ctr,
uint8_t *out, size_t outlen);
/**
* kcapi_cipher_dec_aes_ctr - Convenience function for AES CTR decryption
*
* @key: [in] key buffer
* @keylen: [in] length of key buffer
* @in: [in] ciphertext data buffer
* @inlen: [in] length of in buffer
* @ctr: [in] start counter value to be used for cipher operation
* @out: [out] plaintext data buffer
* @outlen: [in] length of out buffer
*
* The convenience function performs an AES counter mode encryption operation
* using the provided key, the given input buffer and the given IV.
* The output is stored in the out buffer.
*
* The input buffer can be of arbitrary length.
*
* The output buffer must be at least as large as the input buffer.
*
* The start counter can contain all zeros (not a NULL buffer!) and must be
* exactly 16 bytes in size.
*
* The AES type (AES-128, AES-192 or AES-256) is determined by the size
* of the given key. If the key is 16 bytes long, AES-128 is used. A 24 byte
* key implies AES-192 and a 32 byte key implies AES-256.
*
* @return number of bytes generated upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_dec_aes_ctr(const uint8_t *key, uint32_t keylen,
const uint8_t *in, size_t inlen,
const uint8_t *ctr,
uint8_t *out, size_t outlen);
/**
* kcapi_cipher_enc_sm4_cbc - Convenience function for SM4 CBC encryption
*
* @key: [in] key buffer
* @keylen: [in] length of key buffer
* @in: [in] plaintext data buffer
* @inlen: [in] length of in buffer
* @iv: [in] IV to be used for cipher operation
* @out: [out] ciphertext data buffer
* @outlen: [in] length of out buffer
*
* The convenience function performs an SM4 CBC encryption operation
* using the provided key, the given input buffer and the given IV.
* The output is stored in the out buffer.
*
* Note, SM4 CBC requires an input data that is a multiple of 16 bytes.
* If you have data that is not guaranteed to be multiples of 16 bytes, either
* add zero bytes at the end of the buffer to pad it up to a multiple of 16
* bytes. Otherwise, the CTR mode encryption operation may be usable.
*
* The output buffer must be at least as large as the input buffer.
*
* The IV must be exactly 16 bytes in size.
*
* The SM4 key is fixed 16 bytes long.
*
* @return number of bytes generated upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_enc_sm4_cbc(const uint8_t *key, uint32_t keylen,
const uint8_t *in, size_t inlen,
const uint8_t *iv,
uint8_t *out, size_t outlen);
/**
* kcapi_cipher_dec_sm4_cbc - Convenience function for SM4 CBC decryption
*
* @key: [in] key buffer
* @keylen: [in] length of key buffer
* @in: [in] ciphertext data buffer
* @inlen: [in] length of in buffer
* @iv: [in] IV to be used for cipher operation
* @out: [out] plaintext data buffer
* @outlen: [in] length of out buffer
*
* The convenience function performs an SM4 CBC decryption operation
* using the provided key, the given input buffer and the given IV.
* The output is stored in the out buffer.
*
* Note, SM4 CBC requires an input data that is a multiple of 16 bytes.
* If you have data that is not guaranteed to be multiples of 16 bytes, either
* add zero bytes at the end of the buffer to pad it up to a multiple of 16
* bytes. Otherwise, the CTR mode encryption operation may be usable.
*
* The output buffer must be at least as large as the input buffer.
*
* The IV must be exactly 16 bytes in size.
*
* The SM4 key is fixed 16 bytes long.
*
* @return number of bytes generated upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_dec_sm4_cbc(const uint8_t *key, uint32_t keylen,
const uint8_t *in, size_t inlen,
const uint8_t *iv,
uint8_t *out, size_t outlen);
/**
* kcapi_cipher_enc_sm4_ctr - Convenience function for SM4 CTR encryption
*
* @key: [in] key buffer
* @keylen: [in] length of key buffer
* @in: [in] plaintext data buffer
* @inlen: [in] length of in buffer
* @ctr: [in] start counter value to be used for cipher operation
* @out: [out] ciphertext data buffer
* @outlen: [in] length of out buffer
*
* The convenience function performs an SM4 counter mode encryption operation
* using the provided key, the given input buffer and the given IV.
* The output is stored in the out buffer.
*
* The input buffer can be of arbitrary length.
*
* The output buffer must be at least as large as the input buffer.
*
* The start counter can contain all zeros (not a NULL buffer!) and must be
* exactly 16 bytes in size.
*
* The SM4 key is fixed 16 bytes long.
*
* @return number of bytes generated upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_enc_sm4_ctr(const uint8_t *key, uint32_t keylen,
const uint8_t *in, size_t inlen,
const uint8_t *ctr,
uint8_t *out, size_t outlen);
/**
* kcapi_cipher_dec_sm4_ctr - Convenience function for SM4 CTR decryption
*
* @key: [in] key buffer
* @keylen: [in] length of key buffer
* @in: [in] ciphertext data buffer
* @inlen: [in] length of in buffer
* @ctr: [in] start counter value to be used for cipher operation
* @out: [out] plaintext data buffer
* @outlen: [in] length of out buffer
*
* The convenience function performs an SM4 counter mode encryption operation
* using the provided key, the given input buffer and the given IV.
* The output is stored in the out buffer.
*
* The input buffer can be of arbitrary length.
*
* The output buffer must be at least as large as the input buffer.
*
* The start counter can contain all zeros (not a NULL buffer!) and must be
* exactly 16 bytes in size.
*
* The SM4 key is fixed 16 bytes long.
*
* @return number of bytes generated upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_cipher_dec_sm4_ctr(const uint8_t *key, uint32_t keylen,
const uint8_t *in, size_t inlen,
const uint8_t *ctr,
uint8_t *out, size_t outlen);
/**
* kcapi_cipher_ivsize() - return size of IV required for cipher
*
* @handle: [in] cipher handle
*
* @return > 0 specifying the IV size;
* 0 on error
*/
uint32_t kcapi_cipher_ivsize(struct kcapi_handle *handle);
/**
* kcapi_cipher_blocksize() - return size of one block of the cipher
*
* @handle: [in] cipher handle
*
* @return > 0 specifying the block size;
* 0 on error
*/
uint32_t kcapi_cipher_blocksize(struct kcapi_handle *handle);
/**
* DOC: AEAD Cipher API
*
* The following API calls allow using the Authenticated Encryption with
* Associated Data.
*/
/**
* kcapi_aead_init() - initialization of cipher handle
*
* @handle: [out] cipher handle filled during the call
* @ciphername: [in] kernel crypto API cipher name as specified in
* /proc/crypto
* @flags: [in] flags specifying the type of cipher handle
*
* This function initializes an AEAD cipher handle and establishes the
* connection to the kernel.
*
* On success, a pointer to kcapi_handle object is returned in *handle.
* Function kcapi_aead_destroy should be called afterwards to free resources.
*
* @return 0 upon success;
* -ENOENT - algorithm not available;
* -EOPNOTSUPP - AF_ALG family not available;
* -EINVAL - accept syscall failed
* -ENOMEM - cipher handle cannot be allocated
*/
int kcapi_aead_init(struct kcapi_handle **handle, const char *ciphername,
uint32_t flags);
/**
* kcapi_aead_destroy() - close the AEAD handle and release resources
*
* @handle: [in] cipher handle to release
*/
void kcapi_aead_destroy(struct kcapi_handle *handle);
/**
* kcapi_aead_setkey() - set the key for the AEAD handle
*
* @handle: [in] cipher handle
* @key: [in] key buffer
* @keylen: [in] length of key buffer
*
* With this function, the caller sets the key for subsequent encryption or
* decryption operations.
*
* After the caller provided the key, the caller may securely destroy the key
* as it is now maintained by the kernel.
*
* @return 0 upon success;
* a negative errno-style error code if an error occurred
*/
int kcapi_aead_setkey(struct kcapi_handle *handle,
const uint8_t *key, uint32_t keylen);
/**
* kcapi_aead_settaglen() - set authentication tag size
*
* @handle: [in] cipher handle
* @taglen: [in] length of authentication tag
*
* Set the authentication tag size needed for encryption operation. The tag is
* created during encryption operation with the size provided with this call.
*
* @return 0 upon success;
* a negative errno-style error code if an error occurred
*/
int kcapi_aead_settaglen(struct kcapi_handle *handle, uint32_t taglen);
/**
* kcapi_aead_setassoclen() - set authentication data size
*
* @handle: [in] cipher handle
* @assoclen: [in] length of associated data length
*
* The associated data is retained in the cipher handle. During initialization
* of a cipher handle, it is sent to the kernel. The kernel cipher
* implementations may verify the appropriateness of the authentication
* data size and may return an error during initialization if the
* authentication size is not considered appropriate.
*/
void kcapi_aead_setassoclen(struct kcapi_handle *handle, size_t assoclen);
/**
* kcapi_aead_encrypt() - synchronously encrypt AEAD data (one shot)
*
* @handle: [in] cipher handle
* @in: [in] plaintext data buffer
* @inlen: [in] length of plaintext buffer
* @iv: [in] IV to be used for cipher operation
* @out: [out] data buffer holding cipher text and authentication tag
* @outlen: [in] length of out buffer
* @access: [in] kernel access type (KCAPI_ACCESS_HEURISTIC - use internal
* heuristic for fastest kernel access; KCAPI_ACCESS_VMSPLICE - use
* vmsplice access; KCAPI_ACCESS_SENDMSG - sendmsg access)
*
* The AEAD cipher operation requires the furnishing of the associated
* authentication data. In case such data is not required, it can be set to
* NULL and length value must be set to zero.
*
* It is perfectly legal to use the same buffer as the plaintext and
* ciphertext pointers. That would mean that after the encryption operation,
* the plaintext is overwritten with the ciphertext.
*
* The memory should be aligned at the page boundary using
* posix_memalign(sysconf(_SC_PAGESIZE)), If it is not aligned at the page
* boundary, the vmsplice call may not send all data to the kernel.
*
* The IV buffer must be exactly kcapi_cipher_ivsize() bytes in size.
*
* After invoking this function the caller should use
* kcapi_aead_getdata_output() to obtain the resulting ciphertext and
* authentication tag references.
*
* IMPORTANT NOTE: The kernel will only process
* sysconf(_SC_PAGESIZE) * ALG_MAX_PAGES at one time. Longer input data cannot
* be handled by the kernel.
*
* @return number of bytes encrypted upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_aead_encrypt(struct kcapi_handle *handle,
const uint8_t *in, size_t inlen,
const uint8_t *iv,
uint8_t *out, size_t outlen,
int access);
/**
* kcapi_aead_encrypt_aio() - asynchronously encrypt AEAD data (one shot)
*
* @handle: [in] cipher handle
* @iniov: [in] array of scatter-gather list with input buffers
* @outiov: [out] array of scatter-gather list with output buffers
* @iovlen: [in] number of IOVECs in array
* @iv: [in] IV to be used for cipher operation
* @access: [in] kernel access type (KCAPI_ACCESS_HEURISTIC - use internal
* heuristic for fastest kernel access; KCAPI_ACCESS_VMSPLICE - use
* vmsplice access; KCAPI_ACCESS_SENDMSG - sendmsg access)
*
* The AEAD cipher operation requires the furnishing of the associated
* authentication data. In case such data is not required, it can be set to
* NULL and length value must be set to zero.
*
* Each IOVEC is processed with its individual AEAD cipher operation. The
* memory holding the input data will receive the processed data.
*
* The memory should be aligned at the page boundary using
* posix_memalign(sysconf(_SC_PAGESIZE)), If it is not aligned at the page
* boundary, the vmsplice call may not send all data to the kernel.
*
* The IV buffer must be exactly kcapi_cipher_ivsize() bytes in size.
*
* After invoking this function the caller should use
* kcapi_aead_getdata_output() to obtain the resulting ciphertext and
* authentication tag references.
*
* IMPORTANT NOTE: The kernel will only process
* sysconf(_SC_PAGESIZE) * ALG_MAX_PAGES at one time. Longer input data cannot
* be handled by the kernel.
*
* @return number of bytes encrypted upon success;
* a negative errno-style error code if an error occurred
*/
ssize_t kcapi_aead_encrypt_aio(struct kcapi_handle *handle, struct iovec *iniov,
struct iovec *outiov, size_t iovlen,
const uint8_t *iv, int access);
/**
* kcapi_aead_getdata_input() - get the pointers into input buffer
*
* @handle: [in] cipher handle
* @encdata: [in] data buffer returned by the encryption operation
* @encdatalen: [in] size of the encryption data buffer
* @enc: [in] does output buffer hold encryption or decryption result?
* @aad: [out] AD buffer pointer; when set to NULL, no data pointer is
* returned
* @aadlen: [out] length of AD; when aad was set to NULL, no information is
* returned
* @data: [out] pointer to output buffer from AEAD encryption operation
* when set to NULL, no data pointer is returned
* @datalen: [out] length of data buffer; when data was set to NULL, no
* information is returned
* @tag: [out] tag buffer pointer; when set to NULL, no data pointer is
* returned
* @taglen: [out] length of tag; when tag was set to NULL, no information
* is returned
*
* This function is a service function to the consumer to locate the right
* ciphertext buffer offset holding the authentication tag. In addition, it
* provides the consumer with the length of the tag and the length of the
* ciphertext.
*/
void kcapi_aead_getdata_input(struct kcapi_handle *handle,
uint8_t *encdata, size_t encdatalen, int enc,
uint8_t **aad, size_t *aadlen,
uint8_t **data, size_t *datalen,
uint8_t **tag, size_t *taglen);
/**
* kcapi_aead_getdata_output() - get the pointers into output buffer
*
* @handle: [in] cipher handle
* @encdata: [in] data buffer returned by the encryption operation
* @encdatalen: [in] size of the encryption data buffer
* @enc: [in] does output buffer hold encryption or decryption result?
* @aad: [out] AD buffer pointer; when set to NULL, no data pointer is
* returned; returned pointer may also be NULL
* @aadlen: [out] length of AD; when aad was set to NULL, no information is
* returned
* @data: [out] pointer to output buffer from AEAD encryption operation
* when set to NULL, no data pointer is returned
* @datalen: [out] length of data buffer; when data was set to NULL, no
* information is returned
* @tag: [out] tag buffer pointer; when set to NULL, no data pointer is
* returned; returned pointer may also be NULL
* @taglen: [out] length of tag; when tag was set to NULL, no information
* is returned
*
* This function is a service function to the consumer to locate the right
* ciphertext buffer offset holding the authentication tag. In addition, it
* provides the consumer with the length of the tag and the length of the
* ciphertext.
*/
void kcapi_aead_getdata_output(struct kcapi_handle *handle,
uint8_t *encdata, size_t encdatalen, int enc,
uint8_t **aad, size_t *aadlen,
uint8_t **data, size_t *datalen,
uint8_t **tag, size_t *taglen);
/**
* kcapi_aead_decrypt() - synchronously decrypt AEAD data (one shot)
*
* @handle: [in] cipher handle
* @in: [in] ciphertext data buffer
* @inlen: [in] length of in buffer
* @iv: [in] IV to be used for cipher operation
* @out: [out] plaintext data buffer
* @outlen: [in] length of out buffer
* @access: [in] kernel access type (KCAPI_ACCESS_HEURISTIC - use internal
* heuristic for fastest kernel access; KCAPI_ACCESS_VMSPLICE
* use vmsplice access; KCAPI_ACCESS_SENDMSG sendmsg access)
*
* The AEAD cipher operation requires the furnishing of the associated
* authentication data. In case such data is not required, it can be set to
* NULL and length value must be set to zero.
*
* It is perfectly legal to use the same buffer as the plaintext and
* ciphertext pointers. That would mean that after the encryption operation,
* the ciphertext is overwritten with the plaintext.
*
* The memory should be aligned at the page boundary using
* posix_memalign(sysconf(_SC_PAGESIZE)), If it is not aligned at the page
* boundary, the vmsplice call may not send all data to the kernel.
*
* The IV buffer must be exactly kcapi_cipher_ivsize() bytes in size.