BearSSL/inc/bearssl_block.h

1221 lines
39 KiB
C

/*
* Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef BR_BEARSSL_BLOCK_H__
#define BR_BEARSSL_BLOCK_H__
#include <stddef.h>
#include <stdint.h>
/** \file bearssl_block.h
*
* # Block Ciphers
*
* This file documents the API for block ciphers.
*
*
* ## Procedural API
*
* For a block cipher implementation, up to three separate sets of
* functions are provided, for CBC encryption, CBC decryption, and CTR
* encryption/decryption. Each set has its own context structure,
* initialised with the encryption key.
*
* For CBC encryption and decryption, the data to encrypt or decrypt is
* referenced as a sequence of blocks. The implementations assume that
* there is no partial block; no padding is applied or removed. The
* caller is responsible for handling any kind of padding.
*
* Function for CTR encryption are defined only for block ciphers with
* blocks of 16 bytes or more (i.e. AES, but not DES/3DES).
*
* Each implemented block cipher is identified by an "internal name"
* from which are derived the names of structures and functions that
* implement the cipher. For the block cipher of internal name "`xxx`",
* the following are defined:
*
* - `br_xxx_BLOCK_SIZE`
*
* A macro that evaluates to the block size (in bytes) of the
* cipher. For all implemented block ciphers, this value is a
* power of two.
*
* - `br_xxx_cbcenc_keys`
*
* Context structure that contains the subkeys resulting from the key
* expansion. These subkeys are appropriate for CBC encryption. The
* structure first field is called `vtable` and points to the
* appropriate OOP structure.
*
* - `br_xxx_cbcenc_init(br_xxx_cbcenc_keys *ctx, const void *key, size_t len)`
*
* Perform key expansion: subkeys for CBC encryption are computed and
* written in the provided context structure. The key length MUST be
* adequate for the implemented block cipher. This function also sets
* the `vtable` field.
*
* - `br_xxx_cbcenc_run(const br_xxx_cbcenc_keys *ctx, void *iv, void *data, size_t len)`
*
* Perform CBC encryption of `len` bytes, in place. The encrypted data
* replaces the cleartext. `len` MUST be a multiple of the block length
* (if it is not, the function may loop forever or overflow a buffer).
* The IV is provided with the `iv` pointer; it is also updated with
* a copy of the last encrypted block.
*
* - `br_xxx_cbcdec_keys`
*
* Context structure that contains the subkeys resulting from the key
* expansion. These subkeys are appropriate for CBC decryption. The
* structure first field is called `vtable` and points to the
* appropriate OOP structure.
*
* - `br_xxx_cbcdec_init(br_xxx_cbcenc_keys *ctx, const void *key, size_t len)`
*
* Perform key expansion: subkeys for CBC decryption are computed and
* written in the provided context structure. The key length MUST be
* adequate for the implemented block cipher. This function also sets
* the `vtable` field.
*
* - `br_xxx_cbcdec_run(const br_xxx_cbcdec_keys *ctx, void *iv, void *data, size_t num_blocks)`
*
* Perform CBC decryption of `len` bytes, in place. The decrypted data
* replaces the ciphertext. `len` MUST be a multiple of the block length
* (if it is not, the function may loop forever or overflow a buffer).
* The IV is provided with the `iv` pointer; it is also updated with
* a copy of the last _encrypted_ block.
*
* - `br_xxx_ctr_keys`
*
* Context structure that contains the subkeys resulting from the key
* expansion. These subkeys are appropriate for CTR encryption and
* decryption. The structure first field is called `vtable` and
* points to the appropriate OOP structure.
*
* - `br_xxx_ctr_init(br_xxx_ctr_keys *ctx, const void *key, size_t len)`
*
* Perform key expansion: subkeys for CTR encryption and decryption
* are computed and written in the provided context structure. The
* key length MUST be adequate for the implemented block cipher. This
* function also sets the `vtable` field.
*
* - `br_xxx_ctr_run(const br_xxx_ctr_keys *ctx, const void *iv, uint32_t cc, void *data, size_t len)` (returns `uint32_t`)
*
* Perform CTR encryption/decryption of some data. Processing is done
* "in place" (the output data replaces the input data). This function
* implements the "standard incrementing function" from NIST SP800-38A,
* annex B: the IV length shall be 4 bytes less than the block size
* (i.e. 12 bytes for AES) and the counter is the 32-bit value starting
* with `cc`. The data length (`len`) is not necessarily a multiple of
* the block size. The new counter value is returned, which supports
* chunked processing, provided that each chunk length (except possibly
* the last one) is a multiple of the block size.
*
*
* It shall be noted that the key expansion functions return `void`. If
* the provided key length is not allowed, then there will be no error
* reporting; implementations need not validate the key length, thus an
* invalid key length may result in undefined behaviour (e.g. buffer
* overflow).
*
* Subkey structures contain no interior pointer, and no external
* resources are allocated upon key expansion. They can thus be
* discarded without any explicit deallocation.
*
*
* ## Object-Oriented API
*
* Each context structure begins with a field (called `vtable`) that
* points to an instance of a structure that references the relevant
* functions through pointers. Each such structure contains the
* following:
*
* - `context_size`
*
* The size (in bytes) of the context structure for subkeys.
*
* - `block_size`
*
* The cipher block size (in bytes).
*
* - `log_block_size`
*
* The base-2 logarithm of cipher block size (e.g. 4 for blocks
* of 16 bytes).
*
* - `init`
*
* Pointer to the key expansion function.
*
* - `run`
*
* Pointer to the encryption/decryption function.
*
*
* For block cipher "`xxx`", static, constant instances of these
* structures are defined, under the names:
*
* - `br_xxx_cbcenc_vtable`
* - `br_xxx_cbcdec_vtable`
* - `br_xxx_ctr_vtable`
*
*
* ## Implemented Block Ciphers
*
* Provided implementations are:
*
* | Name | Function | Block Size (bytes) | Key lengths (bytes) |
* | :-------- | :------- | :----------------: | :-----------------: |
* | aes_big | AES | 16 | 16, 24 and 32 |
* | aes_small | AES | 16 | 16, 24 and 32 |
* | aes_ct | AES | 16 | 16, 24 and 32 |
* | aes_ct64 | AES | 16 | 16, 24 and 32 |
* | des_ct | DES/3DES | 8 | 8, 16 and 24 |
* | des_tab | DES/3DES | 8 | 8, 16 and 24 |
*
* **Note:** DES/3DES nominally uses keys of 64, 128 and 192 bits (i.e. 8,
* 16 and 24 bytes), but some of the bits are ignored by the algorithm, so
* the _effective_ key lengths, from a security point of view, are 56,
* 112 and 168 bits, respectively.
*
* `aes_big` is a "classical" AES implementation, using tables. It
* is fast but not constant-time, since it makes data-dependent array
* accesses.
*
* `aes_small` is an AES implementation optimized for code size. It
* is substantially slower than `aes_big`; it is not constant-time
* either.
*
* `aes_ct` is a constant-time implementation of AES; its code is about
* as big as that of `aes_big`, while its performance is comparable to
* that of `aes_small`. However, it is constant-time. This
* implementation should thus be considered to be the "default" AES in
* BearSSL, to be used unless the operational context guarantees that a
* non-constant-time implementation is safe, or an architecture-specific
* constant-time implementation can be used (e.g. using dedicated
* hardware opcodes).
*
* `aes_ct64` is another constant-time implementation of AES. It is
* similar to `aes_ct` but uses 64-bit values. On 32-bit machines,
* `aes_ct64` is not faster than `aes_ct`, often a bit slower, and has
* a larger footprint; however, on 64-bit architectures, `aes_ct64`
* is typically twice faster than `aes_ct` for modes that allow parallel
* operations (i.e. CTR, and CBC decryption, but not CBC encryption).
*
* `des_tab` is a classic, table-based implementation of DES/3DES. It
* is not constant-time.
*
* `des_ct` is an constant-time implementation of DES/3DES. It is
* substantially slower than `des_tab`.
*/
/**
* \brief Class type for CBC encryption implementations.
*
* A `br_block_cbcenc_class` instance points to the functions implementing
* a specific block cipher, when used in CBC mode for encrypting data.
*/
typedef struct br_block_cbcenc_class_ br_block_cbcenc_class;
struct br_block_cbcenc_class_ {
/**
* \brief Size (in bytes) of the context structure appropriate
* for containing subkeys.
*/
size_t context_size;
/**
* \brief Size of individual blocks (in bytes).
*/
unsigned block_size;
/**
* \brief Base-2 logarithm of the size of individual blocks,
* expressed in bytes.
*/
unsigned log_block_size;
/**
* \brief Initialisation function.
*
* This function sets the `vtable` field in the context structure.
* The key length MUST be one of the key lengths supported by
* the implementation.
*
* \param ctx context structure to initialise.
* \param key secret key.
* \param key_len key length (in bytes).
*/
void (*init)(const br_block_cbcenc_class **ctx,
const void *key, size_t key_len);
/**
* \brief Run the CBC encryption.
*
* The `iv` parameter points to the IV for this run; it is
* updated with a copy of the last encrypted block. The data
* is encrypted "in place"; its length (`len`) MUST be a
* multiple of the block size.
*
* \param ctx context structure (already initialised).
* \param iv IV for CBC encryption (updated).
* \param data data to encrypt.
* \param len data length (in bytes, multiple of block size).
*/
void (*run)(const br_block_cbcenc_class *const *ctx,
void *iv, void *data, size_t len);
};
/**
* \brief Class type for CBC decryption implementations.
*
* A `br_block_cbcdec_class` instance points to the functions implementing
* a specific block cipher, when used in CBC mode for decrypting data.
*/
typedef struct br_block_cbcdec_class_ br_block_cbcdec_class;
struct br_block_cbcdec_class_ {
/**
* \brief Size (in bytes) of the context structure appropriate
* for containing subkeys.
*/
size_t context_size;
/**
* \brief Size of individual blocks (in bytes).
*/
unsigned block_size;
/**
* \brief Base-2 logarithm of the size of individual blocks,
* expressed in bytes.
*/
unsigned log_block_size;
/**
* \brief Initialisation function.
*
* This function sets the `vtable` field in the context structure.
* The key length MUST be one of the key lengths supported by
* the implementation.
*
* \param ctx context structure to initialise.
* \param key secret key.
* \param key_len key length (in bytes).
*/
void (*init)(const br_block_cbcdec_class **ctx,
const void *key, size_t key_len);
/**
* \brief Run the CBC decryption.
*
* The `iv` parameter points to the IV for this run; it is
* updated with a copy of the last encrypted block. The data
* is decrypted "in place"; its length (`len`) MUST be a
* multiple of the block size.
*
* \param ctx context structure (already initialised).
* \param iv IV for CBC decryption (updated).
* \param data data to decrypt.
* \param len data length (in bytes, multiple of block size).
*/
void (*run)(const br_block_cbcdec_class *const *ctx,
void *iv, void *data, size_t len);
};
/**
* \brief Class type for CTR encryption/decryption implementations.
*
* A `br_block_ctr_class` instance points to the functions implementing
* a specific block cipher, when used in CTR mode for encrypting or
* decrypting data.
*/
typedef struct br_block_ctr_class_ br_block_ctr_class;
struct br_block_ctr_class_ {
/**
* \brief Size (in bytes) of the context structure appropriate
* for containing subkeys.
*/
size_t context_size;
/**
* \brief Size of individual blocks (in bytes).
*/
unsigned block_size;
/**
* \brief Base-2 logarithm of the size of individual blocks,
* expressed in bytes.
*/
unsigned log_block_size;
/**
* \brief Initialisation function.
*
* This function sets the `vtable` field in the context structure.
* The key length MUST be one of the key lengths supported by
* the implementation.
*
* \param ctx context structure to initialise.
* \param key secret key.
* \param key_len key length (in bytes).
*/
void (*init)(const br_block_ctr_class **ctx,
const void *key, size_t key_len);
/**
* \brief Run the CTR encryption or decryption.
*
* The `iv` parameter points to the IV for this run; its
* length is exactly 4 bytes less than the block size (e.g.
* 12 bytes for AES/CTR). The IV is combined with a 32-bit
* block counter to produce the block value which is processed
* with the block cipher.
*
* The data to encrypt or decrypt is updated "in place". Its
* length (`len` bytes) is not required to be a multiple of
* the block size; if the final block is partial, then the
* corresponding key stream bits are dropped.
*
* The resulting counter value is returned.
*
* \param ctx context structure (already initialised).
* \param iv IV for CTR encryption/decryption.
* \param cc initial value for the block counter.
* \param data data to encrypt or decrypt.
* \param len data length (in bytes).
* \return the new block counter value.
*/
uint32_t (*run)(const br_block_ctr_class *const *ctx,
const void *iv, uint32_t cc, void *data, size_t len);
};
/*
* Traditional, table-based AES implementation. It is fast, but uses
* internal tables (in particular a 1 kB table for encryption, another
* 1 kB table for decryption, and a 256-byte table for key schedule),
* and it is not constant-time. In contexts where cache-timing attacks
* apply, this implementation may leak the secret key.
*/
/** \brief AES block size (16 bytes). */
#define br_aes_big_BLOCK_SIZE 16
/**
* \brief Context for AES subkeys (`aes_big` implementation, CBC encryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcenc_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[60];
unsigned num_rounds;
#endif
} br_aes_big_cbcenc_keys;
/**
* \brief Context for AES subkeys (`aes_big` implementation, CBC decryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcdec_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[60];
unsigned num_rounds;
#endif
} br_aes_big_cbcdec_keys;
/**
* \brief Context for AES subkeys (`aes_big` implementation, CTR encryption
* and decryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_ctr_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[60];
unsigned num_rounds;
#endif
} br_aes_big_ctr_keys;
/**
* \brief Class instance for AES CBC encryption (`aes_big` implementation).
*/
extern const br_block_cbcenc_class br_aes_big_cbcenc_vtable;
/**
* \brief Class instance for AES CBC decryption (`aes_big` implementation).
*/
extern const br_block_cbcdec_class br_aes_big_cbcdec_vtable;
/**
* \brief Class instance for AES CTR encryption and decryption
* (`aes_big` implementation).
*/
extern const br_block_ctr_class br_aes_big_ctr_vtable;
/**
* \brief Context initialisation (key schedule) for AES CBC encryption
* (`aes_big` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_big_cbcenc_init(br_aes_big_cbcenc_keys *ctx,
const void *key, size_t len);
/**
* \brief Context initialisation (key schedule) for AES CBC decryption
* (`aes_big` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_big_cbcdec_init(br_aes_big_cbcdec_keys *ctx,
const void *key, size_t len);
/**
* \brief Context initialisation (key schedule) for AES CTR encryption
* and decryption (`aes_big` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_big_ctr_init(br_aes_big_ctr_keys *ctx,
const void *key, size_t len);
/**
* \brief CBC encryption with AES (`aes_big` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to encrypt (updated).
* \param len data length (in bytes, MUST be multiple of 16).
*/
void br_aes_big_cbcenc_run(const br_aes_big_cbcenc_keys *ctx, void *iv,
void *data, size_t len);
/**
* \brief CBC decryption with AES (`aes_big` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to decrypt (updated).
* \param len data length (in bytes, MUST be multiple of 16).
*/
void br_aes_big_cbcdec_run(const br_aes_big_cbcdec_keys *ctx, void *iv,
void *data, size_t len);
/**
* \brief CTR encryption and decryption with AES (`aes_big` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (constant, 12 bytes).
* \param cc initial block counter value.
* \param data data to decrypt (updated).
* \param len data length (in bytes).
* \return new block counter value.
*/
uint32_t br_aes_big_ctr_run(const br_aes_big_ctr_keys *ctx,
const void *iv, uint32_t cc, void *data, size_t len);
/*
* AES implementation optimized for size. It is slower than the
* traditional table-based AES implementation, but requires much less
* code. It still uses data-dependent table accesses (albeit within a
* much smaller 256-byte table), which makes it conceptually vulnerable
* to cache-timing attacks.
*/
/** \brief AES block size (16 bytes). */
#define br_aes_small_BLOCK_SIZE 16
/**
* \brief Context for AES subkeys (`aes_small` implementation, CBC encryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcenc_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[60];
unsigned num_rounds;
#endif
} br_aes_small_cbcenc_keys;
/**
* \brief Context for AES subkeys (`aes_small` implementation, CBC decryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcdec_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[60];
unsigned num_rounds;
#endif
} br_aes_small_cbcdec_keys;
/**
* \brief Context for AES subkeys (`aes_small` implementation, CTR encryption
* and decryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_ctr_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[60];
unsigned num_rounds;
#endif
} br_aes_small_ctr_keys;
/**
* \brief Class instance for AES CBC encryption (`aes_small` implementation).
*/
extern const br_block_cbcenc_class br_aes_small_cbcenc_vtable;
/**
* \brief Class instance for AES CBC decryption (`aes_small` implementation).
*/
extern const br_block_cbcdec_class br_aes_small_cbcdec_vtable;
/**
* \brief Class instance for AES CTR encryption and decryption
* (`aes_small` implementation).
*/
extern const br_block_ctr_class br_aes_small_ctr_vtable;
/**
* \brief Context initialisation (key schedule) for AES CBC encryption
* (`aes_small` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_small_cbcenc_init(br_aes_small_cbcenc_keys *ctx,
const void *key, size_t len);
/**
* \brief Context initialisation (key schedule) for AES CBC decryption
* (`aes_small` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_small_cbcdec_init(br_aes_small_cbcdec_keys *ctx,
const void *key, size_t len);
/**
* \brief Context initialisation (key schedule) for AES CTR encryption
* and decryption (`aes_small` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_small_ctr_init(br_aes_small_ctr_keys *ctx,
const void *key, size_t len);
/**
* \brief CBC encryption with AES (`aes_small` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to encrypt (updated).
* \param len data length (in bytes, MUST be multiple of 16).
*/
void br_aes_small_cbcenc_run(const br_aes_small_cbcenc_keys *ctx, void *iv,
void *data, size_t len);
/**
* \brief CBC decryption with AES (`aes_small` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to decrypt (updated).
* \param len data length (in bytes, MUST be multiple of 16).
*/
void br_aes_small_cbcdec_run(const br_aes_small_cbcdec_keys *ctx, void *iv,
void *data, size_t len);
/**
* \brief CTR encryption and decryption with AES (`aes_small` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (constant, 12 bytes).
* \param cc initial block counter value.
* \param data data to decrypt (updated).
* \param len data length (in bytes).
* \return new block counter value.
*/
uint32_t br_aes_small_ctr_run(const br_aes_small_ctr_keys *ctx,
const void *iv, uint32_t cc, void *data, size_t len);
/*
* Constant-time AES implementation. Its size is similar to that of
* 'aes_big', and its performance is similar to that of 'aes_small' (faster
* decryption, slower encryption). However, it is constant-time, i.e.
* immune to cache-timing and similar attacks.
*/
/** \brief AES block size (16 bytes). */
#define br_aes_ct_BLOCK_SIZE 16
/**
* \brief Context for AES subkeys (`aes_ct` implementation, CBC encryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcenc_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[60];
unsigned num_rounds;
#endif
} br_aes_ct_cbcenc_keys;
/**
* \brief Context for AES subkeys (`aes_ct` implementation, CBC decryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcdec_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[60];
unsigned num_rounds;
#endif
} br_aes_ct_cbcdec_keys;
/**
* \brief Context for AES subkeys (`aes_ct` implementation, CTR encryption
* and decryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_ctr_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[60];
unsigned num_rounds;
#endif
} br_aes_ct_ctr_keys;
/**
* \brief Class instance for AES CBC encryption (`aes_ct` implementation).
*/
extern const br_block_cbcenc_class br_aes_ct_cbcenc_vtable;
/**
* \brief Class instance for AES CBC decryption (`aes_ct` implementation).
*/
extern const br_block_cbcdec_class br_aes_ct_cbcdec_vtable;
/**
* \brief Class instance for AES CTR encryption and decryption
* (`aes_ct` implementation).
*/
extern const br_block_ctr_class br_aes_ct_ctr_vtable;
/**
* \brief Context initialisation (key schedule) for AES CBC encryption
* (`aes_ct` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_ct_cbcenc_init(br_aes_ct_cbcenc_keys *ctx,
const void *key, size_t len);
/**
* \brief Context initialisation (key schedule) for AES CBC decryption
* (`aes_ct` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_ct_cbcdec_init(br_aes_ct_cbcdec_keys *ctx,
const void *key, size_t len);
/**
* \brief Context initialisation (key schedule) for AES CTR encryption
* and decryption (`aes_ct` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_ct_ctr_init(br_aes_ct_ctr_keys *ctx,
const void *key, size_t len);
/**
* \brief CBC encryption with AES (`aes_ct` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to encrypt (updated).
* \param len data length (in bytes, MUST be multiple of 16).
*/
void br_aes_ct_cbcenc_run(const br_aes_ct_cbcenc_keys *ctx, void *iv,
void *data, size_t len);
/**
* \brief CBC decryption with AES (`aes_ct` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to decrypt (updated).
* \param len data length (in bytes, MUST be multiple of 16).
*/
void br_aes_ct_cbcdec_run(const br_aes_ct_cbcdec_keys *ctx, void *iv,
void *data, size_t len);
/**
* \brief CTR encryption and decryption with AES (`aes_ct` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (constant, 12 bytes).
* \param cc initial block counter value.
* \param data data to decrypt (updated).
* \param len data length (in bytes).
* \return new block counter value.
*/
uint32_t br_aes_ct_ctr_run(const br_aes_ct_ctr_keys *ctx,
const void *iv, uint32_t cc, void *data, size_t len);
/*
* 64-bit constant-time AES implementation. It is similar to 'aes_ct'
* but uses 64-bit registers, making it about twice faster than 'aes_ct'
* on 64-bit platforms, while remaining constant-time and with a similar
* code size. (The doubling in performance is only for CBC decryption
* and CTR mode; CBC encryption is non-parallel and cannot benefit from
* the larger registers.)
*/
/** \brief AES block size (16 bytes). */
#define br_aes_ct64_BLOCK_SIZE 16
/**
* \brief Context for AES subkeys (`aes_ct64` implementation, CBC encryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcenc_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint64_t skey[30];
unsigned num_rounds;
#endif
} br_aes_ct64_cbcenc_keys;
/**
* \brief Context for AES subkeys (`aes_ct64` implementation, CBC decryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcdec_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint64_t skey[30];
unsigned num_rounds;
#endif
} br_aes_ct64_cbcdec_keys;
/**
* \brief Context for AES subkeys (`aes_ct64` implementation, CTR encryption
* and decryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_ctr_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint64_t skey[30];
unsigned num_rounds;
#endif
} br_aes_ct64_ctr_keys;
/**
* \brief Class instance for AES CBC encryption (`aes_ct64` implementation).
*/
extern const br_block_cbcenc_class br_aes_ct64_cbcenc_vtable;
/**
* \brief Class instance for AES CBC decryption (`aes_ct64` implementation).
*/
extern const br_block_cbcdec_class br_aes_ct64_cbcdec_vtable;
/**
* \brief Class instance for AES CTR encryption and decryption
* (`aes_ct64` implementation).
*/
extern const br_block_ctr_class br_aes_ct64_ctr_vtable;
/**
* \brief Context initialisation (key schedule) for AES CBC encryption
* (`aes_ct64` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_ct64_cbcenc_init(br_aes_ct64_cbcenc_keys *ctx,
const void *key, size_t len);
/**
* \brief Context initialisation (key schedule) for AES CBC decryption
* (`aes_ct64` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_ct64_cbcdec_init(br_aes_ct64_cbcdec_keys *ctx,
const void *key, size_t len);
/**
* \brief Context initialisation (key schedule) for AES CTR encryption
* and decryption (`aes_ct64` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_aes_ct64_ctr_init(br_aes_ct64_ctr_keys *ctx,
const void *key, size_t len);
/**
* \brief CBC encryption with AES (`aes_ct64` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to encrypt (updated).
* \param len data length (in bytes, MUST be multiple of 16).
*/
void br_aes_ct64_cbcenc_run(const br_aes_ct64_cbcenc_keys *ctx, void *iv,
void *data, size_t len);
/**
* \brief CBC decryption with AES (`aes_ct64` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to decrypt (updated).
* \param len data length (in bytes, MUST be multiple of 16).
*/
void br_aes_ct64_cbcdec_run(const br_aes_ct64_cbcdec_keys *ctx, void *iv,
void *data, size_t len);
/**
* \brief CTR encryption and decryption with AES (`aes_ct64` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (constant, 12 bytes).
* \param cc initial block counter value.
* \param data data to decrypt (updated).
* \param len data length (in bytes).
* \return new block counter value.
*/
uint32_t br_aes_ct64_ctr_run(const br_aes_ct64_ctr_keys *ctx,
const void *iv, uint32_t cc, void *data, size_t len);
/**
* \brief Aggregate structure large enough to be used as context for
* subkeys (CBC encryption) for all AES implementations.
*/
typedef union {
const br_block_cbcenc_class *vtable;
br_aes_big_cbcenc_keys big;
br_aes_small_cbcenc_keys small;
br_aes_ct_cbcenc_keys ct;
br_aes_ct64_cbcenc_keys ct64;
} br_aes_gen_cbcenc_keys;
/**
* \brief Aggregate structure large enough to be used as context for
* subkeys (CBC decryption) for all AES implementations.
*/
typedef union {
const br_block_cbcdec_class *vtable;
br_aes_big_cbcdec_keys big;
br_aes_small_cbcdec_keys small;
br_aes_ct_cbcdec_keys ct;
br_aes_ct64_cbcdec_keys ct64;
} br_aes_gen_cbcdec_keys;
/**
* \brief Aggregate structure large enough to be used as context for
* subkeys (CTR encryption and decryption) for all AES implementations.
*/
typedef union {
const br_block_ctr_class *vtable;
br_aes_big_ctr_keys big;
br_aes_small_ctr_keys small;
br_aes_ct_ctr_keys ct;
br_aes_ct64_ctr_keys ct64;
} br_aes_gen_ctr_keys;
/*
* Traditional, table-based implementation for DES/3DES. Since tables are
* used, cache-timing attacks are conceptually possible.
*/
/** \brief DES/3DES block size (8 bytes). */
#define br_des_tab_BLOCK_SIZE 8
/**
* \brief Context for DES subkeys (`des_tab` implementation, CBC encryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcenc_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[96];
unsigned num_rounds;
#endif
} br_des_tab_cbcenc_keys;
/**
* \brief Context for DES subkeys (`des_tab` implementation, CBC decryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcdec_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[96];
unsigned num_rounds;
#endif
} br_des_tab_cbcdec_keys;
/**
* \brief Class instance for DES CBC encryption (`des_tab` implementation).
*/
extern const br_block_cbcenc_class br_des_tab_cbcenc_vtable;
/**
* \brief Class instance for DES CBC decryption (`des_tab` implementation).
*/
extern const br_block_cbcdec_class br_des_tab_cbcdec_vtable;
/**
* \brief Context initialisation (key schedule) for DES CBC encryption
* (`des_tab` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_des_tab_cbcenc_init(br_des_tab_cbcenc_keys *ctx,
const void *key, size_t len);
/**
* \brief Context initialisation (key schedule) for DES CBC decryption
* (`des_tab` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_des_tab_cbcdec_init(br_des_tab_cbcdec_keys *ctx,
const void *key, size_t len);
/**
* \brief CBC encryption with DES (`des_tab` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to encrypt (updated).
* \param len data length (in bytes, MUST be multiple of 8).
*/
void br_des_tab_cbcenc_run(const br_des_tab_cbcenc_keys *ctx, void *iv,
void *data, size_t len);
/**
* \brief CBC decryption with DES (`des_tab` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to decrypt (updated).
* \param len data length (in bytes, MUST be multiple of 8).
*/
void br_des_tab_cbcdec_run(const br_des_tab_cbcdec_keys *ctx, void *iv,
void *data, size_t len);
/*
* Constant-time implementation for DES/3DES. It is substantially slower
* (by a factor of about 4x), but also immune to cache-timing attacks.
*/
/** \brief DES/3DES block size (8 bytes). */
#define br_des_ct_BLOCK_SIZE 8
/**
* \brief Context for DES subkeys (`des_ct` implementation, CBC encryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcenc_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[96];
unsigned num_rounds;
#endif
} br_des_ct_cbcenc_keys;
/**
* \brief Context for DES subkeys (`des_ct` implementation, CBC decryption).
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/** \brief Pointer to vtable for this context. */
const br_block_cbcdec_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
uint32_t skey[96];
unsigned num_rounds;
#endif
} br_des_ct_cbcdec_keys;
/**
* \brief Class instance for DES CBC encryption (`des_ct` implementation).
*/
extern const br_block_cbcenc_class br_des_ct_cbcenc_vtable;
/**
* \brief Class instance for DES CBC decryption (`des_ct` implementation).
*/
extern const br_block_cbcdec_class br_des_ct_cbcdec_vtable;
/**
* \brief Context initialisation (key schedule) for DES CBC encryption
* (`des_ct` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_des_ct_cbcenc_init(br_des_ct_cbcenc_keys *ctx,
const void *key, size_t len);
/**
* \brief Context initialisation (key schedule) for DES CBC decryption
* (`des_ct` implementation).
*
* \param ctx context to initialise.
* \param key secret key.
* \param len secret key length (in bytes).
*/
void br_des_ct_cbcdec_init(br_des_ct_cbcdec_keys *ctx,
const void *key, size_t len);
/**
* \brief CBC encryption with DES (`des_ct` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to encrypt (updated).
* \param len data length (in bytes, MUST be multiple of 8).
*/
void br_des_ct_cbcenc_run(const br_des_ct_cbcenc_keys *ctx, void *iv,
void *data, size_t len);
/**
* \brief CBC decryption with DES (`des_ct` implementation).
*
* \param ctx context (already initialised).
* \param iv IV (updated).
* \param data data to decrypt (updated).
* \param len data length (in bytes, MUST be multiple of 8).
*/
void br_des_ct_cbcdec_run(const br_des_ct_cbcdec_keys *ctx, void *iv,
void *data, size_t len);
/*
* These structures are large enough to accommodate subkeys for all
* DES/3DES implementations.
*/
/**
* \brief Aggregate structure large enough to be used as context for
* subkeys (CBC encryption) for all DES implementations.
*/
typedef union {
const br_block_cbcenc_class *vtable;
br_des_tab_cbcenc_keys tab;
br_des_ct_cbcenc_keys ct;
} br_des_gen_cbcenc_keys;
/**
* \brief Aggregate structure large enough to be used as context for
* subkeys (CBC decryption) for all DES implementations.
*/
typedef union {
const br_block_cbcdec_class *vtable;
br_des_tab_cbcdec_keys tab;
br_des_ct_cbcdec_keys ct;
} br_des_gen_cbcdec_keys;
#endif