xref: /freebsd/crypto/openssl/fuzz/decoder.c (revision a689bfa4e25af8307709dc12f75b0e02a65abf18)
1 /*
2  * Copyright 2023-2024 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  * https://www.openssl.org/source/license.html
8  * or in the file LICENSE in the source distribution.
9  */
10 
11 #include <openssl/decoder.h>
12 #include <openssl/err.h>
13 #include <openssl/rand.h>
14 #include "fuzzer.h"
15 
16 static ASN1_PCTX *pctx;
17 
18 int FuzzerInitialize(int *argc, char ***argv)
19 {
20     FuzzerSetRand();
21 
22     OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CRYPTO_STRINGS
23             | OPENSSL_INIT_ADD_ALL_CIPHERS
24             | OPENSSL_INIT_ADD_ALL_DIGESTS,
25         NULL);
26 
27     pctx = ASN1_PCTX_new();
28     ASN1_PCTX_set_flags(pctx, ASN1_PCTX_FLAGS_SHOW_ABSENT | ASN1_PCTX_FLAGS_SHOW_SEQUENCE | ASN1_PCTX_FLAGS_SHOW_SSOF | ASN1_PCTX_FLAGS_SHOW_TYPE | ASN1_PCTX_FLAGS_SHOW_FIELD_STRUCT_NAME);
29     ASN1_PCTX_set_str_flags(pctx, ASN1_STRFLGS_UTF8_CONVERT | ASN1_STRFLGS_SHOW_TYPE | ASN1_STRFLGS_DUMP_ALL);
30 
31     ERR_clear_error();
32     CRYPTO_free_ex_index(0, -1);
33     return 1;
34 }
35 
36 int FuzzerTestOneInput(const uint8_t *buf, size_t len)
37 {
38     OSSL_DECODER_CTX *dctx;
39     EVP_PKEY *pkey = NULL;
40     EVP_PKEY_CTX *ctx = NULL;
41     BIO *bio;
42 
43     bio = BIO_new(BIO_s_null());
44     dctx = OSSL_DECODER_CTX_new_for_pkey(&pkey, NULL, NULL, NULL, 0, NULL,
45         NULL);
46     if (dctx == NULL) {
47         return 0;
48     }
49     if (OSSL_DECODER_from_data(dctx, &buf, &len)) {
50         EVP_PKEY *pkey2;
51 
52         EVP_PKEY_print_public(bio, pkey, 1, pctx);
53         EVP_PKEY_print_private(bio, pkey, 1, pctx);
54         EVP_PKEY_print_params(bio, pkey, 1, pctx);
55 
56         pkey2 = EVP_PKEY_dup(pkey);
57         OPENSSL_assert(pkey2 != NULL);
58         EVP_PKEY_eq(pkey, pkey2);
59         EVP_PKEY_free(pkey2);
60 
61         ctx = EVP_PKEY_CTX_new(pkey, NULL);
62         /*
63          * Param check will take too long time on large DH parameters.
64          * Skip it.
65          */
66         if ((!EVP_PKEY_is_a(pkey, "DH") && !EVP_PKEY_is_a(pkey, "DHX"))
67             || EVP_PKEY_get_bits(pkey) <= 2048)
68             EVP_PKEY_param_check(ctx);
69 
70         EVP_PKEY_public_check(ctx);
71         /* Private and pairwise checks are unbounded, skip for large keys. */
72         if (EVP_PKEY_get_bits(pkey) <= 4096) {
73             EVP_PKEY_private_check(ctx);
74             EVP_PKEY_pairwise_check(ctx);
75         }
76         OPENSSL_assert(ctx != NULL);
77         EVP_PKEY_CTX_free(ctx);
78         EVP_PKEY_free(pkey);
79     }
80     OSSL_DECODER_CTX_free(dctx);
81 
82     BIO_free(bio);
83     ERR_clear_error();
84     return 0;
85 }
86 
87 void FuzzerCleanup(void)
88 {
89     ASN1_PCTX_free(pctx);
90     FuzzerClearRand();
91 }
92