1/*
2 * Copyright 1995-2024 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#ifndef OSSL_CRYPTO_PROV_LOCAL_H
11# define OSSL_CRYPTO_PROV_LOCAL_H
12
13# include <openssl/evp.h>
14# include <openssl/core_dispatch.h>
15# include <openssl/core_names.h>
16# include <openssl/params.h>
17# include "internal/tsan_assist.h"
18# include "internal/nelem.h"
19# include "internal/numbers.h"
20# include "prov/provider_ctx.h"
21
22/* How many times to read the TSC as a randomness source. */
23# define TSC_READ_COUNT                 4
24
25/* Maximum reseed intervals */
26# define MAX_RESEED_INTERVAL                     (1 << 24)
27# define MAX_RESEED_TIME_INTERVAL                (1 << 20) /* approx. 12 days */
28
29/* Default reseed intervals */
30# define RESEED_INTERVAL                         (1 << 8)
31# define TIME_INTERVAL                           (60*60)   /* 1 hour */
32
33/*
34 * The number of bytes that constitutes an atomic lump of entropy with respect
35 * to the FIPS 140-2 section 4.9.2 Conditional Tests.  The size is somewhat
36 * arbitrary, the smaller the value, the less entropy is consumed on first
37 * read but the higher the probability of the test failing by accident.
38 *
39 * The value is in bytes.
40 */
41#define CRNGT_BUFSIZ    16
42
43/*
44 * Maximum input size for the DRBG (entropy, nonce, personalization string)
45 *
46 * NIST SP800 90Ar1 allows a maximum of (1 << 35) bits i.e., (1 << 32) bytes.
47 *
48 * We lower it to 'only' INT32_MAX bytes, which is equivalent to 2 gigabytes.
49 */
50# define DRBG_MAX_LENGTH                         INT32_MAX
51
52/* The default nonce */
53#ifdef CHARSET_EBCDIC
54# define DRBG_DEFAULT_PERS_STRING      { 0x4f, 0x70, 0x65, 0x6e, 0x53, 0x53, \
55     0x4c, 0x20, 0x4e, 0x49, 0x53, 0x54, 0x20, 0x53, 0x50, 0x20, 0x38, 0x30, \
56     0x30, 0x2d, 0x39, 0x30, 0x41, 0x20, 0x44, 0x52, 0x42, 0x47, 0x00};
57#else
58# define DRBG_DEFAULT_PERS_STRING                "OpenSSL NIST SP 800-90A DRBG"
59#endif
60
61typedef struct prov_drbg_st PROV_DRBG;
62
63/* DRBG status values */
64typedef enum drbg_status_e {
65    DRBG_UNINITIALISED,
66    DRBG_READY,
67    DRBG_ERROR
68} DRBG_STATUS;
69
70/*
71 * The state of all types of DRBGs.
72 */
73struct prov_drbg_st {
74    CRYPTO_RWLOCK *lock;
75    PROV_CTX *provctx;
76
77    /* Virtual functions are cache here */
78    int (*instantiate)(PROV_DRBG *drbg,
79                       const unsigned char *entropy, size_t entropylen,
80                       const unsigned char *nonce, size_t noncelen,
81                       const unsigned char *pers, size_t perslen);
82    int (*uninstantiate)(PROV_DRBG *ctx);
83    int (*reseed)(PROV_DRBG *drbg, const unsigned char *ent, size_t ent_len,
84                  const unsigned char *adin, size_t adin_len);
85    int (*generate)(PROV_DRBG *, unsigned char *out, size_t outlen,
86                    const unsigned char *adin, size_t adin_len);
87
88    /* Parent PROV_RAND and its dispatch table functions */
89    void *parent;
90    OSSL_FUNC_rand_enable_locking_fn *parent_enable_locking;
91    OSSL_FUNC_rand_lock_fn *parent_lock;
92    OSSL_FUNC_rand_unlock_fn *parent_unlock;
93    OSSL_FUNC_rand_get_ctx_params_fn *parent_get_ctx_params;
94    OSSL_FUNC_rand_nonce_fn *parent_nonce;
95    OSSL_FUNC_rand_get_seed_fn *parent_get_seed;
96    OSSL_FUNC_rand_clear_seed_fn *parent_clear_seed;
97
98    const OSSL_DISPATCH *parent_dispatch;
99
100    /*
101     * Stores the return value of openssl_get_fork_id() as of when we last
102     * reseeded.  The DRBG reseeds automatically whenever drbg->fork_id !=
103     * openssl_get_fork_id().  Used to provide fork-safety and reseed this
104     * DRBG in the child process.
105     */
106    int fork_id;
107    unsigned short flags; /* various external flags */
108
109    /*
110     * The following parameters are setup by the per-type "init" function.
111     *
112     * The supported types and their init functions are:
113     *    (1) CTR_DRBG:  drbg_ctr_init().
114     *    (2) HMAC_DRBG: drbg_hmac_init().
115     *    (3) HASH_DRBG: drbg_hash_init().
116     *
117     * The parameters are closely related to the ones described in
118     * section '10.2.1 CTR_DRBG' of [NIST SP 800-90Ar1], with one
119     * crucial difference: In the NIST standard, all counts are given
120     * in bits, whereas in OpenSSL entropy counts are given in bits
121     * and buffer lengths are given in bytes.
122     *
123     * Since this difference has lead to some confusion in the past,
124     * (see [GitHub Issue #2443], formerly [rt.openssl.org #4055])
125     * the 'len' suffix has been added to all buffer sizes for
126     * clarification.
127     */
128
129    unsigned int strength;
130    size_t max_request;
131    size_t min_entropylen, max_entropylen;
132    size_t min_noncelen, max_noncelen;
133    size_t max_perslen, max_adinlen;
134
135    /*
136     * Counts the number of generate requests since the last reseed
137     * (Starts at 1). This value is the reseed_counter as defined in
138     * NIST SP 800-90Ar1
139     */
140    unsigned int generate_counter;
141    /*
142     * Maximum number of generate requests until a reseed is required.
143     * This value is ignored if it is zero.
144     */
145    unsigned int reseed_interval;
146    /* Stores the time when the last reseeding occurred */
147    time_t reseed_time;
148    /*
149     * Specifies the maximum time interval (in seconds) between reseeds.
150     * This value is ignored if it is zero.
151     */
152    time_t reseed_time_interval;
153    /*
154     * Counts the number of reseeds since instantiation.
155     * This value is ignored if it is zero.
156     *
157     * This counter is used only for seed propagation from the <master> DRBG
158     * to its two children, the <public> and <private> DRBG. This feature is
159     * very special and its sole purpose is to ensure that any randomness which
160     * is added by PROV_add() or PROV_seed() will have an immediate effect on
161     * the output of PROV_bytes() resp. PROV_priv_bytes().
162     */
163    TSAN_QUALIFIER unsigned int reseed_counter;
164    unsigned int reseed_next_counter;
165    unsigned int parent_reseed_counter;
166
167    size_t seedlen;
168    DRBG_STATUS state;
169
170    /* DRBG specific data */
171    void *data;
172
173    /* Entropy and nonce gathering callbacks */
174    void *callback_arg;
175    OSSL_INOUT_CALLBACK *get_entropy_fn;
176    OSSL_CALLBACK *cleanup_entropy_fn;
177    OSSL_INOUT_CALLBACK *get_nonce_fn;
178    OSSL_CALLBACK *cleanup_nonce_fn;
179};
180
181PROV_DRBG *ossl_rand_drbg_new
182    (void *provctx, void *parent, const OSSL_DISPATCH *parent_dispatch,
183     int (*dnew)(PROV_DRBG *ctx),
184     void (*dfree)(void *vctx),
185     int (*instantiate)(PROV_DRBG *drbg,
186                        const unsigned char *entropy, size_t entropylen,
187                        const unsigned char *nonce, size_t noncelen,
188                        const unsigned char *pers, size_t perslen),
189     int (*uninstantiate)(PROV_DRBG *ctx),
190     int (*reseed)(PROV_DRBG *drbg, const unsigned char *ent, size_t ent_len,
191                   const unsigned char *adin, size_t adin_len),
192     int (*generate)(PROV_DRBG *, unsigned char *out, size_t outlen,
193                     const unsigned char *adin, size_t adin_len));
194void ossl_rand_drbg_free(PROV_DRBG *drbg);
195
196int ossl_prov_drbg_instantiate(PROV_DRBG *drbg, unsigned int strength,
197                               int prediction_resistance,
198                               const unsigned char *pers, size_t perslen);
199
200int ossl_prov_drbg_uninstantiate(PROV_DRBG *drbg);
201
202int ossl_prov_drbg_reseed(PROV_DRBG *drbg, int prediction_resistance,
203                          const unsigned char *ent, size_t ent_len,
204                          const unsigned char *adin, size_t adinlen);
205
206int ossl_prov_drbg_generate(PROV_DRBG *drbg, unsigned char *out, size_t outlen,
207                            unsigned int strength, int prediction_resistance,
208                            const unsigned char *adin, size_t adinlen);
209
210/* Seeding api */
211OSSL_FUNC_rand_get_seed_fn ossl_drbg_get_seed;
212OSSL_FUNC_rand_clear_seed_fn ossl_drbg_clear_seed;
213
214/* Verify that an array of numeric values is all zero */
215#define PROV_DRBG_VERYIFY_ZEROIZATION(v)    \
216    {                                       \
217        size_t i;                           \
218                                            \
219        for (i = 0; i < OSSL_NELEM(v); i++) \
220            if ((v)[i] != 0)                \
221                return 0;                   \
222    }
223
224/* locking api */
225OSSL_FUNC_rand_enable_locking_fn ossl_drbg_enable_locking;
226OSSL_FUNC_rand_lock_fn ossl_drbg_lock;
227OSSL_FUNC_rand_unlock_fn ossl_drbg_unlock;
228
229/* Common parameters for all of our DRBGs */
230int ossl_drbg_get_ctx_params(PROV_DRBG *drbg, OSSL_PARAM params[]);
231int ossl_drbg_set_ctx_params(PROV_DRBG *drbg, const OSSL_PARAM params[]);
232
233#define OSSL_PARAM_DRBG_SETTABLE_CTX_COMMON                                      \
234    OSSL_PARAM_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS, NULL),             \
235    OSSL_PARAM_uint64(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL, NULL)
236
237#define OSSL_PARAM_DRBG_GETTABLE_CTX_COMMON                             \
238    OSSL_PARAM_int(OSSL_RAND_PARAM_STATE, NULL),                        \
239    OSSL_PARAM_uint(OSSL_RAND_PARAM_STRENGTH, NULL),                    \
240    OSSL_PARAM_size_t(OSSL_RAND_PARAM_MAX_REQUEST, NULL),               \
241    OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MIN_ENTROPYLEN, NULL),            \
242    OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_ENTROPYLEN, NULL),            \
243    OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MIN_NONCELEN, NULL),              \
244    OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_NONCELEN, NULL),              \
245    OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_PERSLEN, NULL),               \
246    OSSL_PARAM_size_t(OSSL_DRBG_PARAM_MAX_ADINLEN, NULL),               \
247    OSSL_PARAM_uint(OSSL_DRBG_PARAM_RESEED_COUNTER, NULL),              \
248    OSSL_PARAM_time_t(OSSL_DRBG_PARAM_RESEED_TIME, NULL),               \
249    OSSL_PARAM_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS, NULL),             \
250    OSSL_PARAM_uint64(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL, NULL)
251
252/* Continuous test "entropy" calls */
253size_t ossl_crngt_get_entropy(PROV_DRBG *drbg,
254                              unsigned char **pout,
255                              int entropy, size_t min_len, size_t max_len,
256                              int prediction_resistance);
257void ossl_crngt_cleanup_entropy(PROV_DRBG *drbg,
258                                unsigned char *out, size_t outlen);
259
260#endif
261