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
null_init(NULLMD_CTX * ctx)18 static int null_init(NULLMD_CTX *ctx)
19 {
20 return 1;
21 }
22
null_update(NULLMD_CTX * ctx,const void * data,size_t datalen)23 static int null_update(NULLMD_CTX *ctx, const void *data, size_t datalen)
24 {
25 return 1;
26 }
27
null_final(unsigned char * md,NULLMD_CTX * ctx)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