fuzz/fuzz_rand.c

   1 /*
   2  * Copyright 2016-2021 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
  16 static OSSL_FUNC_rand_newctx_fn fuzz_rand_newctx;
  17 static OSSL_FUNC_rand_freectx_fn fuzz_rand_freectx;
  18 static OSSL_FUNC_rand_instantiate_fn fuzz_rand_instantiate;
  19 static OSSL_FUNC_rand_uninstantiate_fn fuzz_rand_uninstantiate;
  20 static OSSL_FUNC_rand_generate_fn fuzz_rand_generate;
  21 static OSSL_FUNC_rand_gettable_ctx_params_fn fuzz_rand_gettable_ctx_params;
  22 static OSSL_FUNC_rand_get_ctx_params_fn fuzz_rand_get_ctx_params;
  23 static OSSL_FUNC_rand_enable_locking_fn fuzz_rand_enable_locking;
  24
  25 static 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
  35 static void fuzz_rand_freectx(ossl_unused void *vrng)
  36 {
  37     OPENSSL_free(vrng);
  38 }
  39
  40 static 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 {
  46     *(int *)vrng = EVP_RAND_STATE_READY;
  47     return 1;
  48 }
  49
  50 static int fuzz_rand_uninstantiate(ossl_unused void *vrng)
  51 {
  52     *(int *)vrng = EVP_RAND_STATE_UNINITIALISED;
  53     return 1;
  54 }
  55
  56 static int fuzz_rand_generate(ossl_unused void *vdrbg,
  57                               unsigned char *out, size_t outlen,
  58                               ossl_unused unsigned int strength,
  59                               ossl_unused int prediction_resistance,
  60                               ossl_unused const unsigned char *adin,
  61                               ossl_unused size_t adinlen)
  62 {
  63     unsigned char val = 1;
  64     size_t i;
  65
  66     for (i = 0; i < outlen; i++)
  67         out[i] = val++;
  68     return 1;
  69 }
  70
  71 static int fuzz_rand_enable_locking(ossl_unused void *vrng)
  72 {
  73     return 1;
  74 }
  75
  76 static int fuzz_rand_get_ctx_params(void *vrng, OSSL_PARAM params[])
  77 {
  78     OSSL_PARAM *p;
  79
  80     p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_STATE);
  81     if (p != NULL && !OSSL_PARAM_set_int(p, *(int *)vrng))
  82         return 0;
  83
  84     p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_STRENGTH);
  85     if (p != NULL && !OSSL_PARAM_set_int(p, 500))
  86         return 0;
  87
  88     p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_MAX_REQUEST);
  89     if (p != NULL && !OSSL_PARAM_set_size_t(p, INT_MAX))
  90         return 0;
  91     return 1;
  92 }
  93
  94 static const OSSL_PARAM *fuzz_rand_gettable_ctx_params(ossl_unused void *provctx)
  95 {
  96     static const OSSL_PARAM known_gettable_ctx_params[] = {
  97         OSSL_PARAM_int(OSSL_RAND_PARAM_STATE, NULL),
  98         OSSL_PARAM_uint(OSSL_RAND_PARAM_STRENGTH, NULL),
  99         OSSL_PARAM_size_t(OSSL_RAND_PARAM_MAX_REQUEST, NULL),
 100         OSSL_PARAM_END
 101     };
 102     return known_gettable_ctx_params;
 103 }
 104
 105 static const OSSL_DISPATCH fuzz_rand_functions[] = {
 106     { OSSL_FUNC_RAND_NEWCTX, (void (*)(void))fuzz_rand_newctx },
 107     { OSSL_FUNC_RAND_FREECTX, (void (*)(void))fuzz_rand_freectx },
 108     { OSSL_FUNC_RAND_INSTANTIATE, (void (*)(void))fuzz_rand_instantiate },
 109     { OSSL_FUNC_RAND_UNINSTANTIATE, (void (*)(void))fuzz_rand_uninstantiate },
 110     { OSSL_FUNC_RAND_GENERATE, (void (*)(void))fuzz_rand_generate },
 111     { OSSL_FUNC_RAND_ENABLE_LOCKING, (void (*)(void))fuzz_rand_enable_locking },
 112     { OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS,
 113       (void(*)(void))fuzz_rand_gettable_ctx_params },
 114     { OSSL_FUNC_RAND_GET_CTX_PARAMS, (void(*)(void))fuzz_rand_get_ctx_params },
 115     { 0, NULL }
 116 };
 117
 118 static const OSSL_ALGORITHM fuzz_rand_rand[] = {
 119     { "fuzz", "provider=fuzz-rand", fuzz_rand_functions },
 120     { NULL, NULL, NULL }
 121 };
 122
 123 static const OSSL_ALGORITHM *fuzz_rand_query(void *provctx,
 124                                              int operation_id,
 125                                              int *no_cache)
 126 {
 127     *no_cache = 0;
 128     switch (operation_id) {
 129     case OSSL_OP_RAND:
 130         return fuzz_rand_rand;
 131     }
 132     return NULL;
 133 }
 134
 135 /* Functions we provide to the core */
 136 static const OSSL_DISPATCH fuzz_rand_method[] = {
 137     { OSSL_FUNC_PROVIDER_TEARDOWN, (void (*)(void))OSSL_LIB_CTX_free },
 138     { OSSL_FUNC_PROVIDER_QUERY_OPERATION, (void (*)(void))fuzz_rand_query },
 139     { 0, NULL }
 140 };
 141
 142 static int fuzz_rand_provider_init(const OSSL_CORE_HANDLE *handle,
 143                                    const OSSL_DISPATCH *in,
 144                                    const OSSL_DISPATCH **out, void **provctx)
 145 {
 146     *provctx = OSSL_LIB_CTX_new();
 147     *out = fuzz_rand_method;
 148     return 1;
 149 }
 150
 151 static OSSL_PROVIDER *r_prov;
 152
 153 void FuzzerSetRand(void)
 154 {
 155     if (!OSSL_PROVIDER_add_builtin(NULL, "fuzz-rand", fuzz_rand_provider_init)
 156         || !RAND_set_DRBG_type(NULL, "fuzz", NULL, NULL, NULL)
 157         || (r_prov = OSSL_PROVIDER_try_load(NULL, "fuzz-rand", 1)) == NULL)
 158         exit(1);
 159 }
 160
 161 void FuzzerClearRand(void)
 162 {
 163     OSSL_PROVIDER_unload(r_prov);
 164 }