1/*
2 * Copyright 2016-2022 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/core_names.h>
12#include <openssl/rand.h>
13#include <openssl/provider.h>
14#include "fuzzer.h"
15
16static OSSL_FUNC_rand_newctx_fn fuzz_rand_newctx;
17static OSSL_FUNC_rand_freectx_fn fuzz_rand_freectx;
18static OSSL_FUNC_rand_instantiate_fn fuzz_rand_instantiate;
19static OSSL_FUNC_rand_uninstantiate_fn fuzz_rand_uninstantiate;
20static OSSL_FUNC_rand_generate_fn fuzz_rand_generate;
21static OSSL_FUNC_rand_gettable_ctx_params_fn fuzz_rand_gettable_ctx_params;
22static OSSL_FUNC_rand_get_ctx_params_fn fuzz_rand_get_ctx_params;
23static OSSL_FUNC_rand_enable_locking_fn fuzz_rand_enable_locking;
24
25static void *fuzz_rand_newctx(
26         void *provctx, void *parent, const OSSL_DISPATCH *parent_dispatch)
27{
28    int *st = OPENSSL_malloc(sizeof(*st));
29
30    if (st != NULL)
31        *st = EVP_RAND_STATE_UNINITIALISED;
32    return st;
33}
34
35static void fuzz_rand_freectx(ossl_unused void *vrng)
36{
37    OPENSSL_free(vrng);
38}
39
40static int fuzz_rand_instantiate(ossl_unused void *vrng,
41                                 ossl_unused unsigned int strength,
42                                 ossl_unused int prediction_resistance,
43                                 ossl_unused const unsigned char *pstr,
44                                 ossl_unused size_t pstr_len,
45                                 ossl_unused const OSSL_PARAM params[])
46{
47    *(int *)vrng = EVP_RAND_STATE_READY;
48    return 1;
49}
50
51static int fuzz_rand_uninstantiate(ossl_unused void *vrng)
52{
53    *(int *)vrng = EVP_RAND_STATE_UNINITIALISED;
54    return 1;
55}
56
57static int fuzz_rand_generate(ossl_unused void *vdrbg,
58                              unsigned char *out, size_t outlen,
59                              ossl_unused unsigned int strength,
60                              ossl_unused int prediction_resistance,
61                              ossl_unused const unsigned char *adin,
62                              ossl_unused size_t adinlen)
63{
64    unsigned char val = 1;
65    size_t i;
66
67    for (i = 0; i < outlen; i++)
68        out[i] = val++;
69    return 1;
70}
71
72static int fuzz_rand_enable_locking(ossl_unused void *vrng)
73{
74    return 1;
75}
76
77static int fuzz_rand_get_ctx_params(void *vrng, OSSL_PARAM params[])
78{
79    OSSL_PARAM *p;
80
81    p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_STATE);
82    if (p != NULL && !OSSL_PARAM_set_int(p, *(int *)vrng))
83        return 0;
84
85    p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_STRENGTH);
86    if (p != NULL && !OSSL_PARAM_set_int(p, 500))
87        return 0;
88
89    p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_MAX_REQUEST);
90    if (p != NULL && !OSSL_PARAM_set_size_t(p, INT_MAX))
91        return 0;
92    return 1;
93}
94
95static const OSSL_PARAM *fuzz_rand_gettable_ctx_params(ossl_unused void *vrng,
96                                                       ossl_unused void *provctx)
97{
98    static const OSSL_PARAM known_gettable_ctx_params[] = {
99        OSSL_PARAM_int(OSSL_RAND_PARAM_STATE, NULL),
100        OSSL_PARAM_uint(OSSL_RAND_PARAM_STRENGTH, NULL),
101        OSSL_PARAM_size_t(OSSL_RAND_PARAM_MAX_REQUEST, NULL),
102        OSSL_PARAM_END
103    };
104    return known_gettable_ctx_params;
105}
106
107static const OSSL_DISPATCH fuzz_rand_functions[] = {
108    { OSSL_FUNC_RAND_NEWCTX, (void (*)(void))fuzz_rand_newctx },
109    { OSSL_FUNC_RAND_FREECTX, (void (*)(void))fuzz_rand_freectx },
110    { OSSL_FUNC_RAND_INSTANTIATE, (void (*)(void))fuzz_rand_instantiate },
111    { OSSL_FUNC_RAND_UNINSTANTIATE, (void (*)(void))fuzz_rand_uninstantiate },
112    { OSSL_FUNC_RAND_GENERATE, (void (*)(void))fuzz_rand_generate },
113    { OSSL_FUNC_RAND_ENABLE_LOCKING, (void (*)(void))fuzz_rand_enable_locking },
114    { OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS,
115      (void(*)(void))fuzz_rand_gettable_ctx_params },
116    { OSSL_FUNC_RAND_GET_CTX_PARAMS, (void(*)(void))fuzz_rand_get_ctx_params },
117    { 0, NULL }
118};
119
120static const OSSL_ALGORITHM fuzz_rand_rand[] = {
121    { "fuzz", "provider=fuzz-rand", fuzz_rand_functions },
122    { NULL, NULL, NULL }
123};
124
125static const OSSL_ALGORITHM *fuzz_rand_query(void *provctx,
126                                             int operation_id,
127                                             int *no_cache)
128{
129    *no_cache = 0;
130    switch (operation_id) {
131    case OSSL_OP_RAND:
132        return fuzz_rand_rand;
133    }
134    return NULL;
135}
136
137/* Functions we provide to the core */
138static const OSSL_DISPATCH fuzz_rand_method[] = {
139    { OSSL_FUNC_PROVIDER_TEARDOWN, (void (*)(void))OSSL_LIB_CTX_free },
140    { OSSL_FUNC_PROVIDER_QUERY_OPERATION, (void (*)(void))fuzz_rand_query },
141    { 0, NULL }
142};
143
144static int fuzz_rand_provider_init(const OSSL_CORE_HANDLE *handle,
145                                   const OSSL_DISPATCH *in,
146                                   const OSSL_DISPATCH **out, void **provctx)
147{
148    *provctx = OSSL_LIB_CTX_new();
149    if (*provctx == NULL)
150        return 0;
151    *out = fuzz_rand_method;
152    return 1;
153}
154
155static OSSL_PROVIDER *r_prov;
156
157void FuzzerSetRand(void)
158{
159    if (!OSSL_PROVIDER_add_builtin(NULL, "fuzz-rand", fuzz_rand_provider_init)
160        || !RAND_set_DRBG_type(NULL, "fuzz", NULL, NULL, NULL)
161        || (r_prov = OSSL_PROVIDER_try_load(NULL, "fuzz-rand", 1)) == NULL)
162        exit(1);
163}
164
165void FuzzerClearRand(void)
166{
167    OSSL_PROVIDER_unload(r_prov);
168}
169