1/* Copyright (c) (2021,2022) Apple Inc. All rights reserved.
2 *
3 * corecrypto is licensed under Apple Inc.’s Internal Use License Agreement (which
4 * is contained in the License.txt file distributed with corecrypto) and only to
5 * people who accept that license. IMPORTANT: Any license rights granted to you by
6 * Apple Inc. (if any) are limited to internal use within your organization only on
7 * devices and computers you own or control, for the sole purpose of verifying the
8 * security characteristics and correct functioning of the Apple Software. You may
9 * not, directly or indirectly, redistribute the Apple Software or any portions thereof.
10 */
11
12#ifndef _CORECRYPTO_CCDRBG_DF_H_
13#define _CORECRYPTO_CCDRBG_DF_H_
14
15#include <corecrypto/cc.h>
16#include <corecrypto/ccmode_impl.h>
17
18// This is an interface for derivation functions for DRBGs to convert
19// high-entropy inputs into key material. Because this interface is
20// intended for internal usage, we declare only the type names and
21// initialization functions here.
22
23typedef struct ccdrbg_df_ctx ccdrbg_df_ctx_t;
24
25struct ccdrbg_df_ctx {
26 int (*derive_keys)(const ccdrbg_df_ctx_t *ctx,
27 size_t inputs_count,
28 const cc_iovec_t *inputs,
29 size_t keys_nbytes,
30 void *keys);
31};
32
33// This is a block-cipher-based instantiation of the derivation
34// function for use in the CTR-DRBG.
35
36typedef struct ccdrbg_df_bc_ctx ccdrbg_df_bc_ctx_t;
37
38struct ccdrbg_df_bc_ctx {
39 ccdrbg_df_ctx_t df_ctx;
40 const struct ccmode_cbc *cbc_info;
41 size_t key_nbytes;
42
43 // See ccmode_impl.h.
44 cc_ctx_decl_field(cccbc_ctx, CCCBC_MAX_CTX_SIZE, cbc_ctx);
45};
46
47/*!
48 @function ccdrbg_df_bc_init
49 @abstract Initialize a block-cipher-based derivation function
50 @param ctx The derivation function context
51 @param cbc_info A descriptor for a CBC mode of a block cipher
52 @param key_nbytes The length of the key to use in the derivation function
53
54 @discussion Note that a fixed key is used internally, so only the
55 key length needs to be specified.
56 @return 0 if successful; negative otherwise
57*/
58CC_WARN_RESULT
59CC_NONNULL_ALL
60int ccdrbg_df_bc_init(ccdrbg_df_bc_ctx_t *ctx,
61 const struct ccmode_cbc *cbc_info,
62 size_t key_nbytes);
63
64#endif /* _CORECRYPTO_CCDRBG_DF_H_ */
65