/* Copyright (c) (2021,2022) Apple Inc. All rights reserved.
*
* corecrypto is licensed under Apple Inc.’s Internal Use License Agreement (which
* is contained in the License.txt file distributed with corecrypto) and only to
* people who accept that license. IMPORTANT: Any license rights granted to you by
* Apple Inc. (if any) are limited to internal use within your organization only on
* devices and computers you own or control, for the sole purpose of verifying the
* security characteristics and correct functioning of the Apple Software. You may
* not, directly or indirectly, redistribute the Apple Software or any portions thereof.
*/
#ifndef _CORECRYPTO_CCDRBG_DF_H_
#define _CORECRYPTO_CCDRBG_DF_H_
#include <corecrypto/cc.h>
#include <corecrypto/ccmode_impl.h>
// This is an interface for derivation functions for DRBGs to convert
// high-entropy inputs into key material. Because this interface is
// intended for internal usage, we declare only the type names and
// initialization functions here.
typedef struct ccdrbg_df_ctx ccdrbg_df_ctx_t;
struct ccdrbg_df_ctx {
int (*derive_keys)(const ccdrbg_df_ctx_t *ctx,
size_t inputs_count,
const cc_iovec_t *inputs,
size_t keys_nbytes,
void *keys);
};
// This is a block-cipher-based instantiation of the derivation
// function for use in the CTR-DRBG.
typedef struct ccdrbg_df_bc_ctx ccdrbg_df_bc_ctx_t;
struct ccdrbg_df_bc_ctx {
ccdrbg_df_ctx_t df_ctx;
const struct ccmode_cbc *cbc_info;
size_t key_nbytes;
// See ccmode_impl.h.
cc_ctx_decl_field(cccbc_ctx, CCCBC_MAX_CTX_SIZE, cbc_ctx);
};
/*!
@function ccdrbg_df_bc_init
@abstract Initialize a block-cipher-based derivation function
@param ctx The derivation function context
@param cbc_info A descriptor for a CBC mode of a block cipher
@param key_nbytes The length of the key to use in the derivation function
@discussion Note that a fixed key is used internally, so only the
key length needs to be specified.
@return 0 if successful; negative otherwise
*/
CC_WARN_RESULT
CC_NONNULL_ALL
int ccdrbg_df_bc_init(ccdrbg_df_bc_ctx_t *ctx,
const struct ccmode_cbc *cbc_info,
size_t key_nbytes);
#endif /* _CORECRYPTO_CCDRBG_DF_H_ */