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 23 typedef struct ccdrbg_df_ctx ccdrbg_df_ctx_t; 24 25 struct 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 36 typedef struct ccdrbg_df_bc_ctx ccdrbg_df_bc_ctx_t; 37 38 struct 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 */ 58 CC_WARN_RESULT 59 CC_NONNULL_ALL 60 int 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