1 /* 2 * Copyright 2021 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include <openssl/crypto.h> 11 #include "prov/digestcommon.h" 12 #include "prov/implementations.h" 13 14 typedef struct { 15 unsigned char nothing; 16 } NULLMD_CTX; 17 18 static int null_init(NULLMD_CTX *ctx) 19 { 20 return 1; 21 } 22 23 static int null_update(NULLMD_CTX *ctx, const void *data, size_t datalen) 24 { 25 return 1; 26 } 27 28 static int null_final(unsigned char *md, NULLMD_CTX *ctx) 29 { 30 return 1; 31 } 32 33 /* 34 * We must override the PROV_FUNC_DIGEST_FINAL as dgstsize == 0 35 * and that would cause compilation warnings with the default implementation. 36 */ 37 #undef PROV_FUNC_DIGEST_FINAL 38 #define PROV_FUNC_DIGEST_FINAL(name, dgstsize, fin) \ 39 static OSSL_FUNC_digest_final_fn name##_internal_final; \ 40 static int name##_internal_final(void *ctx, unsigned char *out, size_t *outl, \ 41 size_t outsz) \ 42 { \ 43 if (ossl_prov_is_running() && fin(out, ctx)) { \ 44 *outl = dgstsize; \ 45 return 1; \ 46 } \ 47 return 0; \ 48 } 49 50 IMPLEMENT_digest_functions(nullmd, NULLMD_CTX, 51 0, 0, 0, 52 null_init, null_update, null_final) 53