Coverage Report

Created: 2026-04-12 07:08

next uncovered line (L), next uncovered region (R), next uncovered branch (B)
/src/openssl/crypto/x509/v3_purp.c
Line
Count
Source
1
/*
2
 * Copyright 1999-2026 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 <stdio.h>
11
#include "internal/cryptlib.h"
12
#include "internal/numbers.h"
13
#include <openssl/x509v3.h>
14
#include <openssl/x509_vfy.h>
15
#include "crypto/x509.h"
16
#include "internal/tsan_assist.h"
17
#include "x509_local.h"
18
#include "crypto/objects/obj_dat.h"
19
#include "internal/hashfunc.h"
20
21
static int check_ssl_ca(const X509 *x);
22
static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
23
    int non_leaf);
24
static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
25
    int non_leaf);
26
static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
27
    int non_leaf);
28
static int purpose_smime(const X509 *x, int non_leaf);
29
static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
30
    int non_leaf);
31
static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
32
    int non_leaf);
33
static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
34
    int non_leaf);
35
static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
36
    int non_leaf);
37
static int check_purpose_code_sign(const X509_PURPOSE *xp, const X509 *x,
38
    int non_leaf);
39
static int no_check_purpose(const X509_PURPOSE *xp, const X509 *x,
40
    int non_leaf);
41
static int check_purpose_ocsp_helper(const X509_PURPOSE *xp, const X509 *x,
42
    int non_leaf);
43
44
static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b);
45
static void xptable_free(X509_PURPOSE *p);
46
47
/* note that the id must be unique and for the standard entries == idx + 1 */
48
static X509_PURPOSE xstandard[] = {
49
    { X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
50
        check_purpose_ssl_client, "SSL client", "sslclient", NULL },
51
    { X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
52
        check_purpose_ssl_server, "SSL server", "sslserver", NULL },
53
    { X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
54
        check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL },
55
    { X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
56
        "S/MIME signing", "smimesign", NULL },
57
    { X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
58
        check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL },
59
    { X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
60
        "CRL signing", "crlsign", NULL },
61
    { X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check_purpose,
62
        "Any Purpose", "any",
63
        NULL },
64
    { X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, check_purpose_ocsp_helper,
65
        "OCSP helper", "ocsphelper", NULL },
66
    { X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
67
        check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign",
68
        NULL },
69
    { X509_PURPOSE_CODE_SIGN, X509_TRUST_OBJECT_SIGN, 0,
70
        check_purpose_code_sign, "Code signing", "codesign",
71
        NULL },
72
};
73
74
0
#define X509_PURPOSE_COUNT OSSL_NELEM(xstandard)
75
76
/* the id must be unique, but there may be gaps and maybe table is not sorted */
77
static STACK_OF(X509_PURPOSE) *xptable = NULL;
78
79
static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b)
80
0
{
81
0
    return (*a)->purpose - (*b)->purpose;
82
0
}
83
84
int X509_check_purpose(const X509 *x, int id, int non_leaf)
85
0
{
86
0
    int idx;
87
0
    const X509_PURPOSE *pt;
88
89
    /*
90
     * TODO: This cast can be dropped when https://github.com/openssl/openssl/pull/30067
91
     * gets merged
92
     */
93
0
    if (!ossl_x509v3_cache_extensions((X509 *)x))
94
0
        return -1;
95
0
    if (id == -1)
96
0
        return 1;
97
98
0
    idx = X509_PURPOSE_get_by_id(id);
99
0
    if (idx == -1)
100
0
        return -1;
101
0
    pt = X509_PURPOSE_get0(idx);
102
0
    return pt->check_purpose(pt, x, non_leaf);
103
0
}
104
105
/* resets to default (any) purpose if purpose == X509_PURPOSE_DEFAULT_ANY (0) */
106
int X509_PURPOSE_set(int *p, int purpose)
107
0
{
108
0
    if (purpose != X509_PURPOSE_DEFAULT_ANY && X509_PURPOSE_get_by_id(purpose) == -1) {
109
0
        ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_PURPOSE);
110
0
        return 0;
111
0
    }
112
0
    *p = purpose;
113
0
    return 1;
114
0
}
115
116
int X509_PURPOSE_get_count(void)
117
0
{
118
0
    if (!xptable)
119
0
        return X509_PURPOSE_COUNT;
120
0
    return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
121
0
}
122
123
/* find smallest identifier not yet taken - note there might be gaps */
124
int X509_PURPOSE_get_unused_id(ossl_unused OSSL_LIB_CTX *libctx)
125
0
{
126
0
    int id = X509_PURPOSE_MAX + 1;
127
128
0
    while (X509_PURPOSE_get_by_id(id) != -1)
129
0
        id++;
130
0
    return id; /* is guaranteed to be unique and > X509_PURPOSE_MAX and != 0 */
131
0
}
132
133
X509_PURPOSE *X509_PURPOSE_get0(int idx)
134
0
{
135
0
    if (idx < 0)
136
0
        return NULL;
137
0
    if (idx < (int)X509_PURPOSE_COUNT)
138
0
        return xstandard + idx;
139
0
    return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
140
0
}
141
142
int X509_PURPOSE_get_by_sname(const char *sname)
143
0
{
144
0
    int i;
145
0
    X509_PURPOSE *xptmp;
146
147
0
    for (i = 0; i < X509_PURPOSE_get_count(); i++) {
148
0
        xptmp = X509_PURPOSE_get0(i);
149
0
        if (strcmp(xptmp->sname, sname) == 0)
150
0
            return i;
151
0
    }
152
0
    return -1;
153
0
}
154
155
/* Returns -1 on error, else an index => 0 in standard/extended purpose table */
156
int X509_PURPOSE_get_by_id(int purpose)
157
0
{
158
0
    X509_PURPOSE tmp;
159
0
    int idx;
160
161
0
    if (purpose >= X509_PURPOSE_MIN && purpose <= X509_PURPOSE_MAX)
162
0
        return purpose - X509_PURPOSE_MIN;
163
0
    if (xptable == NULL)
164
0
        return -1;
165
0
    tmp.purpose = purpose;
166
0
    idx = sk_X509_PURPOSE_find(xptable, &tmp);
167
0
    if (idx < 0)
168
0
        return -1;
169
0
    return idx + X509_PURPOSE_COUNT;
170
0
}
171
172
/*
173
 * Add purpose entry identified by |sname|. |id| must be >= X509_PURPOSE_MIN.
174
 * May also be used to modify existing entry, including changing its id.
175
 */
176
int X509_PURPOSE_add(int id, int trust, int flags,
177
    int (*ck)(const X509_PURPOSE *, const X509 *, int),
178
    const char *name, const char *sname, void *arg)
179
0
{
180
0
    int old_id = 0;
181
0
    int idx;
182
0
    X509_PURPOSE *ptmp;
183
184
0
    if (id < X509_PURPOSE_MIN) {
185
0
        ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_PURPOSE);
186
0
        return 0;
187
0
    }
188
0
    if (trust < X509_TRUST_DEFAULT || name == NULL || sname == NULL || ck == NULL) {
189
0
        ERR_raise(ERR_LIB_X509V3, ERR_R_PASSED_INVALID_ARGUMENT);
190
0
        return 0;
191
0
    }
192
193
    /* This is set according to what we change: application can't set it */
194
0
    flags &= ~X509_PURPOSE_DYNAMIC;
195
    /* This will always be set for application modified trust entries */
196
0
    flags |= X509_PURPOSE_DYNAMIC_NAME;
197
198
    /* Get existing entry if any */
199
0
    idx = X509_PURPOSE_get_by_sname(sname);
200
0
    if (idx == -1) { /* Need a new entry */
201
0
        if (X509_PURPOSE_get_by_id(id) != -1) {
202
0
            ERR_raise(ERR_LIB_X509V3, X509V3_R_PURPOSE_NOT_UNIQUE);
203
0
            return 0;
204
0
        }
205
0
        if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL)
206
0
            return 0;
207
0
        ptmp->flags = X509_PURPOSE_DYNAMIC;
208
0
    } else {
209
0
        ptmp = X509_PURPOSE_get0(idx);
210
0
        old_id = ptmp->purpose;
211
0
        if (id != old_id && X509_PURPOSE_get_by_id(id) != -1) {
212
0
            ERR_raise(ERR_LIB_X509V3, X509V3_R_PURPOSE_NOT_UNIQUE);
213
0
            return 0;
214
0
        }
215
0
    }
216
217
    /* OPENSSL_free existing name if dynamic */
218
0
    if ((ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) != 0) {
219
0
        OPENSSL_free(ptmp->name);
220
0
        OPENSSL_free(ptmp->sname);
221
0
    }
222
    /* Dup supplied name */
223
0
    ptmp->name = OPENSSL_strdup(name);
224
0
    ptmp->sname = OPENSSL_strdup(sname);
225
0
    if (ptmp->name == NULL || ptmp->sname == NULL)
226
0
        goto err;
227
    /* Keep the dynamic flag of existing entry */
228
0
    ptmp->flags &= X509_PURPOSE_DYNAMIC;
229
    /* Set all other flags */
230
0
    ptmp->flags |= flags;
231
232
0
    ptmp->purpose = id;
233
0
    ptmp->trust = trust;
234
0
    ptmp->check_purpose = ck;
235
0
    ptmp->usr_data = arg;
236
237
    /* If its a new entry manage the dynamic table */
238
0
    if (idx == -1) {
239
0
        if (xptable == NULL
240
0
            && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) {
241
0
            ERR_raise(ERR_LIB_X509V3, ERR_R_CRYPTO_LIB);
242
0
            goto err;
243
0
        }
244
0
        if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
245
0
            ERR_raise(ERR_LIB_X509V3, ERR_R_CRYPTO_LIB);
246
0
            goto err;
247
0
        }
248
0
    } else if (id != old_id) {
249
        /* on changing existing entry id, make sure to reset 'sorted' */
250
0
        (void)sk_X509_PURPOSE_set(xptable, idx, ptmp);
251
0
    }
252
0
    return 1;
253
0
err:
254
0
    if (idx == -1) {
255
0
        OPENSSL_free(ptmp->name);
256
0
        OPENSSL_free(ptmp->sname);
257
0
        OPENSSL_free(ptmp);
258
0
    }
259
0
    return 0;
260
0
}
261
262
static void xptable_free(X509_PURPOSE *p)
263
0
{
264
0
    if (p == NULL)
265
0
        return;
266
0
    if ((p->flags & X509_PURPOSE_DYNAMIC) != 0) {
267
0
        if ((p->flags & X509_PURPOSE_DYNAMIC_NAME) != 0) {
268
0
            OPENSSL_free(p->name);
269
0
            OPENSSL_free(p->sname);
270
0
        }
271
0
        OPENSSL_free(p);
272
0
    }
273
0
}
274
275
void X509_PURPOSE_cleanup(void)
276
0
{
277
0
    sk_X509_PURPOSE_pop_free(xptable, xptable_free);
278
0
    xptable = NULL;
279
0
}
280
281
int X509_PURPOSE_get_id(const X509_PURPOSE *xp)
282
0
{
283
0
    return xp->purpose;
284
0
}
285
286
char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
287
0
{
288
0
    return xp->name;
289
0
}
290
291
char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
292
0
{
293
0
    return xp->sname;
294
0
}
295
296
int X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
297
0
{
298
0
    return xp->trust;
299
0
}
300
301
static int nid_cmp(const int *a, const int *b)
302
0
{
303
0
    return *a - *b;
304
0
}
305
306
DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
307
IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
308
309
int X509_supported_extension(const X509_EXTENSION *ex)
310
0
{
311
    /*
312
     * This table is a list of the NIDs of supported extensions: that is
313
     * those which are used by the verify process. If an extension is
314
     * critical and doesn't appear in this list then the verify process will
315
     * normally reject the certificate. The list must be kept in numerical
316
     * order because it will be searched using bsearch.
317
     */
318
0
    static const int supported_nids[] = {
319
0
        NID_netscape_cert_type, /* 71 */
320
0
        NID_key_usage, /* 83 */
321
0
        NID_subject_alt_name, /* 85 */
322
0
        NID_basic_constraints, /* 87 */
323
0
        NID_certificate_policies, /* 89 */
324
0
        NID_crl_distribution_points, /* 103 */
325
0
        NID_ext_key_usage, /* 126 */
326
0
#ifndef OPENSSL_NO_RFC3779
327
0
        NID_sbgp_ipAddrBlock, /* 290 */
328
0
        NID_sbgp_autonomousSysNum, /* 291 */
329
0
#endif
330
0
        NID_id_pkix_OCSP_noCheck, /* 369 */
331
0
        NID_policy_constraints, /* 401 */
332
0
        NID_proxyCertInfo, /* 663 */
333
0
        NID_name_constraints, /* 666 */
334
0
        NID_policy_mappings, /* 747 */
335
0
        NID_inhibit_any_policy /* 748 */
336
0
    };
337
338
0
    int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
339
340
0
    if (ex_nid == NID_undef)
341
0
        return 0;
342
343
0
    if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
344
0
        return 1;
345
0
    return 0;
346
0
}
347
348
/* Returns 1 on success, 0 if x is invalid, -1 on (internal) error. */
349
static int setup_dp(const X509 *x, DIST_POINT *dp)
350
0
{
351
0
    const X509_NAME *iname = NULL;
352
0
    int i;
353
354
0
    if (dp->distpoint == NULL && sk_GENERAL_NAME_num(dp->CRLissuer) <= 0) {
355
0
        ERR_raise(ERR_LIB_X509, X509_R_INVALID_DISTPOINT);
356
0
        return 0;
357
0
    }
358
0
    if (dp->reasons != NULL) {
359
0
        if (dp->reasons->length > 0)
360
0
            dp->dp_reasons = dp->reasons->data[0];
361
0
        if (dp->reasons->length > 1)
362
0
            dp->dp_reasons |= (dp->reasons->data[1] << 8);
363
0
        dp->dp_reasons &= CRLDP_ALL_REASONS;
364
0
    } else {
365
0
        dp->dp_reasons = CRLDP_ALL_REASONS;
366
0
    }
367
0
    if (dp->distpoint == NULL || dp->distpoint->type != 1)
368
0
        return 1;
369
370
    /* Handle name fragment given by nameRelativeToCRLIssuer */
371
    /*
372
     * Note that the below way of determining iname is not really compliant
373
     * with https://tools.ietf.org/html/rfc5280#section-4.2.1.13
374
     * According to it, sk_GENERAL_NAME_num(dp->CRLissuer) MUST be <= 1
375
     * and any CRLissuer could be of type different to GEN_DIRNAME.
376
     */
377
0
    for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
378
0
        GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
379
380
0
        if (gen->type == GEN_DIRNAME) {
381
0
            iname = gen->d.directoryName;
382
0
            break;
383
0
        }
384
0
    }
385
0
    if (iname == NULL)
386
0
        iname = X509_get_issuer_name(x);
387
0
    return DIST_POINT_set_dpname(dp->distpoint, iname) ? 1 : -1;
388
0
}
389
390
/* Return 1 on success, 0 if x is invalid, -1 on (internal) error. */
391
static int setup_crldp(const X509 *x, STACK_OF(DIST_POINT) **tmp_crldp)
392
0
{
393
0
    int i;
394
395
0
    *tmp_crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
396
0
    if (*tmp_crldp == NULL && i != -1)
397
0
        return 0;
398
399
0
    for (i = 0; i < sk_DIST_POINT_num(*tmp_crldp); i++) {
400
0
        int res = setup_dp(x, sk_DIST_POINT_value(*tmp_crldp, i));
401
402
0
        if (res < 1)
403
0
            return res;
404
0
    }
405
0
    return 1;
406
0
}
407
408
/* Check that issuer public key algorithm matches subject signature algorithm */
409
static int check_sig_alg_match(const EVP_PKEY *issuer_key, const X509 *subject)
410
0
{
411
0
    int subj_sig_nid;
412
413
0
    if (issuer_key == NULL)
414
0
        return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
415
0
    if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
416
0
            NULL, &subj_sig_nid)
417
0
        == 0)
418
0
        return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
419
0
    if (EVP_PKEY_is_a(issuer_key, OBJ_nid2sn(subj_sig_nid))
420
0
        || (EVP_PKEY_is_a(issuer_key, "RSA") && subj_sig_nid == NID_rsassaPss))
421
0
        return X509_V_OK;
422
0
    return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
423
0
}
424
425
static unsigned long oid_hash(const void *p)
426
0
{
427
0
    const ASN1_OBJECT *a = p;
428
429
0
    return (unsigned long)ossl_fnv1a_hash((uint8_t *)a->data, a->length);
430
0
}
431
432
static int oid_cmp(const void *a, const void *b)
433
0
{
434
0
    return OBJ_cmp((const ASN1_OBJECT *)a, (const ASN1_OBJECT *)b);
435
0
}
436
437
/*
438
 * Scan all extensions of a certificate to collect extension-related flags.
439
 * Detects duplicate extensions (RFC 5280 section 4.2), the presence of a
440
 * freshest CRL extension and unsupported critical extensions.
441
 *
442
 * In the future, if needed, this scanning function could return the index
443
 * of the offending extension on error, allowing the caller to identify which
444
 * extension caused the problem and report it via ERR_raise_data().
445
 */
446
static void scan_ext_flags(const X509 *x509, uint32_t *flags)
447
0
{
448
0
    OPENSSL_LHASH *h = NULL;
449
0
    uint8_t ex_bitset[(NUM_NID + 7) / 8];
450
451
0
    memset(ex_bitset, 0, sizeof(ex_bitset));
452
    /* A certificate MUST NOT include more than one instance of an extension. */
453
0
    for (int i = 0; i < X509_get_ext_count(x509); i++) {
454
0
        const X509_EXTENSION *ex = X509_get_ext(x509, i);
455
0
        const ASN1_OBJECT *a = X509_EXTENSION_get_object(ex);
456
0
        int nid = OBJ_obj2nid(a);
457
458
        /*
459
         * Known NIDs within the build-time bitset limit are checked for
460
         * duplicates in constant time. Unknown OIDs and dynamically registered
461
         * NIDs that exceed the limit fall back to duplicate detection via a
462
         * hash table.
463
         */
464
0
        if (nid > NID_undef && nid < NUM_NID) {
465
0
            unsigned int ex_bit = nid;
466
467
0
            if ((ex_bitset[ex_bit >> 3] & (1u << (ex_bit & 7))) != 0) {
468
0
                *flags |= EXFLAG_DUPLICATE;
469
0
                break;
470
0
            }
471
0
            ex_bitset[ex_bit >> 3] |= (1u << (ex_bit & 7));
472
0
        } else {
473
            /*
474
             * Extensions with unknown NID (NID_undef) and dynamically
475
             * registered NIDs are handled here by hashing the OID (data/length).
476
             * A zero-length OID should not reach this point, but we check for
477
             * it anyway and assign the EXFLAG_INVALID flag if it does.
478
             */
479
0
            if (a->length < 1) {
480
0
                *flags |= EXFLAG_INVALID;
481
0
                break;
482
0
            }
483
            /*
484
             * Hashing the OID should be manageable more cheaply as well, and
485
             * without additional dynamic allocations. In the case of this
486
             * corner case, it’s not a problem at all, but the other duplicate
487
             * detections also require hashing, so for the sake of consistency
488
             * it would make sense to use a cheaper construct here later as well.
489
             */
490
0
            if (h == NULL && (h = OPENSSL_LH_new(oid_hash, oid_cmp)) == NULL)
491
0
                break;
492
0
            if (OPENSSL_LH_insert(h, (void *)a) != NULL) {
493
0
                *flags |= EXFLAG_DUPLICATE;
494
0
                break;
495
0
            }
496
0
        }
497
0
        if (nid == NID_freshest_crl)
498
0
            *flags |= EXFLAG_FRESHEST;
499
0
        if (!X509_EXTENSION_get_critical(ex))
500
0
            continue;
501
0
        if (!X509_supported_extension(ex)) {
502
0
            *flags |= EXFLAG_CRITICAL;
503
0
            break;
504
0
        }
505
0
    }
506
0
    OPENSSL_LH_free(h);
507
0
}
508
509
0
#define V1_ROOT (EXFLAG_V1 | EXFLAG_SS)
510
#define ku_reject(x, usage) \
511
0
    (((x)->ex_flags & EXFLAG_KUSAGE) != 0 && ((x)->ex_kusage & (usage)) == 0)
512
#define xku_reject(x, usage) \
513
0
    (((x)->ex_flags & EXFLAG_XKUSAGE) != 0 && ((x)->ex_xkusage & (usage)) == 0)
514
#define ns_reject(x, usage) \
515
0
    (((x)->ex_flags & EXFLAG_NSCERT) != 0 && ((x)->ex_nscert & (usage)) == 0)
516
517
/*
518
 * Cache info on various X.509v3 extensions and further derived information,
519
 * e.g., if cert 'x' is self-issued, in x->ex_flags and other internal fields.
520
 * x->sha1_hash is filled in, or else EXFLAG_NO_FINGERPRINT is set in x->flags.
521
 * X509_SIG_INFO_VALID is set in x->flags if x->siginf was filled successfully.
522
 * Set EXFLAG_INVALID and return 0 in case the certificate is invalid.
523
 *
524
 * This is usually called by side-effect on objects, and forces us to keep
525
 * mutable X509 objects around. We should really make this go away.
526
 * In the interest of being able to do so, this function explicitly takes
527
 * a const argument and casts away const.
528
 */
529
int ossl_x509v3_cache_extensions(const X509 *const_x)
530
0
{
531
0
    BASIC_CONSTRAINTS *bs;
532
0
    PROXY_CERT_INFO_EXTENSION *pci;
533
0
    ASN1_BIT_STRING *usage;
534
0
    ASN1_BIT_STRING *ns;
535
0
    EXTENDED_KEY_USAGE *extusage;
536
0
    int i;
537
0
    int res;
538
0
    uint32_t tmp_ex_flags;
539
0
    unsigned char tmp_sha1_hash[SHA_DIGEST_LENGTH];
540
0
    long tmp_ex_pathlen;
541
0
    long tmp_ex_pcpathlen;
542
0
    uint32_t tmp_ex_kusage;
543
0
    uint32_t tmp_ex_xkusage;
544
0
    uint32_t tmp_ex_nscert;
545
0
    ASN1_OCTET_STRING *tmp_skid;
546
0
    AUTHORITY_KEYID *tmp_akid;
547
0
    STACK_OF(GENERAL_NAME) *tmp_altname;
548
0
    NAME_CONSTRAINTS *tmp_nc;
549
0
    STACK_OF(DIST_POINT) *tmp_crldp = NULL;
550
0
    X509_SIG_INFO tmp_siginf;
551
552
0
#ifdef tsan_ld_acq
553
    /* Fast lock-free check, see end of the function for details. */
554
0
    if (tsan_ld_acq((TSAN_QUALIFIER int *)&const_x->ex_cached))
555
0
        return (const_x->ex_flags & EXFLAG_INVALID) == 0;
556
0
#endif
557
558
0
    if (!CRYPTO_THREAD_read_lock(const_x->lock))
559
0
        return 0;
560
0
    tmp_ex_flags = const_x->ex_flags;
561
0
    tmp_ex_pcpathlen = const_x->ex_pcpathlen;
562
0
    tmp_ex_kusage = const_x->ex_kusage;
563
0
    tmp_ex_nscert = const_x->ex_nscert;
564
565
0
    if ((tmp_ex_flags & EXFLAG_SET) != 0) { /* Cert has already been processed */
566
0
        CRYPTO_THREAD_unlock(const_x->lock);
567
0
        return (tmp_ex_flags & EXFLAG_INVALID) == 0;
568
0
    }
569
570
0
    ERR_set_mark();
571
572
    /* Cache the SHA1 digest of the cert */
573
0
    if (!X509_digest(const_x, EVP_sha1(), tmp_sha1_hash, NULL))
574
0
        tmp_ex_flags |= EXFLAG_NO_FINGERPRINT;
575
576
    /* V1 should mean no extensions ... */
577
0
    if (X509_get_version(const_x) == X509_VERSION_1)
578
0
        tmp_ex_flags |= EXFLAG_V1;
579
580
    /* Handle basic constraints */
581
0
    tmp_ex_pathlen = -1;
582
0
    if ((bs = X509_get_ext_d2i(const_x, NID_basic_constraints, &i, NULL)) != NULL) {
583
0
        if (bs->ca)
584
0
            tmp_ex_flags |= EXFLAG_CA;
585
0
        if (bs->pathlen != NULL) {
586
            /*
587
             * The error case !bs->ca is checked by check_chain()
588
             * in case ctx->param->flags & X509_V_FLAG_X509_STRICT
589
             */
590
0
            if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
591
0
                ERR_raise(ERR_LIB_X509V3, X509V3_R_NEGATIVE_PATHLEN);
592
0
                tmp_ex_flags |= EXFLAG_INVALID;
593
0
            } else {
594
0
                tmp_ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
595
0
            }
596
0
        }
597
0
        BASIC_CONSTRAINTS_free(bs);
598
0
        tmp_ex_flags |= EXFLAG_BCONS;
599
0
    } else if (i != -1) {
600
0
        tmp_ex_flags |= EXFLAG_INVALID;
601
0
    }
602
603
    /* Handle proxy certificates */
604
0
    if ((pci = X509_get_ext_d2i(const_x, NID_proxyCertInfo, &i, NULL)) != NULL) {
605
0
        if ((tmp_ex_flags & EXFLAG_CA) != 0
606
0
            || X509_get_ext_by_NID(const_x, NID_subject_alt_name, -1) >= 0
607
0
            || X509_get_ext_by_NID(const_x, NID_issuer_alt_name, -1) >= 0) {
608
0
            tmp_ex_flags |= EXFLAG_INVALID;
609
0
        }
610
0
        if (pci->pcPathLengthConstraint != NULL)
611
0
            tmp_ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
612
0
        else
613
0
            tmp_ex_pcpathlen = -1;
614
0
        PROXY_CERT_INFO_EXTENSION_free(pci);
615
0
        tmp_ex_flags |= EXFLAG_PROXY;
616
0
    } else if (i != -1) {
617
0
        tmp_ex_flags |= EXFLAG_INVALID;
618
0
    }
619
620
    /* Handle (basic) key usage */
621
0
    if ((usage = X509_get_ext_d2i(const_x, NID_key_usage, &i, NULL)) != NULL) {
622
0
        tmp_ex_kusage = 0;
623
0
        if (usage->length > 0) {
624
0
            tmp_ex_kusage = usage->data[0];
625
0
            if (usage->length > 1)
626
0
                tmp_ex_kusage |= usage->data[1] << 8;
627
0
        }
628
0
        tmp_ex_flags |= EXFLAG_KUSAGE;
629
0
        ASN1_BIT_STRING_free(usage);
630
        /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */
631
0
        if (tmp_ex_kusage == 0) {
632
0
            ERR_raise(ERR_LIB_X509V3, X509V3_R_EMPTY_KEY_USAGE);
633
0
            tmp_ex_flags |= EXFLAG_INVALID;
634
0
        }
635
0
    } else if (i != -1) {
636
0
        tmp_ex_flags |= EXFLAG_INVALID;
637
0
    }
638
639
    /* Handle extended key usage */
640
0
    tmp_ex_xkusage = 0;
641
0
    if ((extusage = X509_get_ext_d2i(const_x, NID_ext_key_usage, &i, NULL)) != NULL) {
642
0
        tmp_ex_flags |= EXFLAG_XKUSAGE;
643
0
        for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
644
0
            switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
645
0
            case NID_server_auth:
646
0
                tmp_ex_xkusage |= XKU_SSL_SERVER;
647
0
                break;
648
0
            case NID_client_auth:
649
0
                tmp_ex_xkusage |= XKU_SSL_CLIENT;
650
0
                break;
651
0
            case NID_email_protect:
652
0
                tmp_ex_xkusage |= XKU_SMIME;
653
0
                break;
654
0
            case NID_code_sign:
655
0
                tmp_ex_xkusage |= XKU_CODE_SIGN;
656
0
                break;
657
0
            case NID_ms_sgc:
658
0
            case NID_ns_sgc:
659
0
                tmp_ex_xkusage |= XKU_SGC;
660
0
                break;
661
0
            case NID_OCSP_sign:
662
0
                tmp_ex_xkusage |= XKU_OCSP_SIGN;
663
0
                break;
664
0
            case NID_time_stamp:
665
0
                tmp_ex_xkusage |= XKU_TIMESTAMP;
666
0
                break;
667
0
            case NID_dvcs:
668
0
                tmp_ex_xkusage |= XKU_DVCS;
669
0
                break;
670
0
            case NID_anyExtendedKeyUsage:
671
0
                tmp_ex_xkusage |= XKU_ANYEKU;
672
0
                break;
673
0
            default:
674
                /* Ignore unknown extended key usage */
675
0
                break;
676
0
            }
677
0
        }
678
0
        sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
679
0
    } else if (i != -1) {
680
0
        tmp_ex_flags |= EXFLAG_INVALID;
681
0
    }
682
683
    /* Handle legacy Netscape extension */
684
0
    if ((ns = X509_get_ext_d2i(const_x, NID_netscape_cert_type, &i, NULL)) != NULL) {
685
0
        if (ns->length > 0)
686
0
            tmp_ex_nscert = ns->data[0];
687
0
        else
688
0
            tmp_ex_nscert = 0;
689
0
        tmp_ex_flags |= EXFLAG_NSCERT;
690
0
        ASN1_BIT_STRING_free(ns);
691
0
    } else if (i != -1) {
692
0
        tmp_ex_flags |= EXFLAG_INVALID;
693
0
    }
694
695
    /* Handle subject key identifier and issuer/authority key identifier */
696
0
    tmp_skid = X509_get_ext_d2i(const_x, NID_subject_key_identifier, &i, NULL);
697
0
    if (tmp_skid == NULL && i != -1)
698
0
        tmp_ex_flags |= EXFLAG_INVALID;
699
700
0
    tmp_akid = X509_get_ext_d2i(const_x, NID_authority_key_identifier, &i, NULL);
701
0
    if (tmp_akid == NULL && i != -1)
702
0
        tmp_ex_flags |= EXFLAG_INVALID;
703
704
    /* Setting EXFLAG_SS is equivalent to ossl_x509_likely_issued(const_x, const_x) == X509_V_OK */
705
0
    if (X509_NAME_cmp(X509_get_subject_name(const_x), X509_get_issuer_name(const_x)) == 0) {
706
0
        tmp_ex_flags |= EXFLAG_SI; /* Certificate is self-issued: subject == issuer */
707
        /*
708
         * When the SKID is missing, which is rare for self-issued certs,
709
         * we could afford doing the (accurate) actual self-signature check, but
710
         * decided against it for efficiency reasons and according to RFC 5280,
711
         * CA certs MUST have an SKID and non-root certs MUST have an AKID.
712
         */
713
0
        if (X509_check_akid(const_x, tmp_akid) == X509_V_OK
714
0
            && check_sig_alg_match(X509_get0_pubkey(const_x), const_x) == X509_V_OK) {
715
            /*
716
             * Assume self-signed if the signature alg matches the pkey alg and
717
             * AKID is missing or matches respective fields in the same cert
718
             * Not checking if any given key usage extension allows signing.
719
             */
720
0
            tmp_ex_flags |= EXFLAG_SS;
721
0
        }
722
0
    }
723
724
    /* Handle subject alternative names and various other extensions */
725
0
    tmp_altname = X509_get_ext_d2i(const_x, NID_subject_alt_name, &i, NULL);
726
0
    if (tmp_altname == NULL && i != -1)
727
0
        tmp_ex_flags |= EXFLAG_INVALID;
728
0
    tmp_nc = X509_get_ext_d2i(const_x, NID_name_constraints, &i, NULL);
729
0
    if (tmp_nc == NULL && i != -1)
730
0
        tmp_ex_flags |= EXFLAG_INVALID;
731
732
    /* Handle CRL distribution point entries */
733
0
    res = setup_crldp(const_x, &tmp_crldp);
734
0
    if (res == 0)
735
0
        tmp_ex_flags |= EXFLAG_INVALID;
736
737
0
#ifndef OPENSSL_NO_RFC3779
738
0
    STACK_OF(IPAddressFamily) *tmp_rfc3779_addr
739
0
        = X509_get_ext_d2i(const_x, NID_sbgp_ipAddrBlock, &i, NULL);
740
0
    if (tmp_rfc3779_addr == NULL && i != -1)
741
0
        tmp_ex_flags |= EXFLAG_INVALID;
742
743
0
    struct ASIdentifiers_st *tmp_rfc3779_asid
744
0
        = X509_get_ext_d2i(const_x, NID_sbgp_autonomousSysNum, &i, NULL);
745
0
    if (tmp_rfc3779_asid == NULL && i != -1)
746
0
        tmp_ex_flags |= EXFLAG_INVALID;
747
0
#endif
748
749
0
    scan_ext_flags(const_x, &tmp_ex_flags);
750
751
    /* Set x->siginf, ignoring errors due to unsupported algos */
752
0
    (void)ossl_x509_init_sig_info(const_x, &tmp_siginf);
753
754
0
    tmp_ex_flags |= EXFLAG_SET; /* Indicate that cert has been processed */
755
0
    ERR_pop_to_mark();
756
757
0
    CRYPTO_THREAD_unlock(const_x->lock);
758
    /*
759
     * Now that we've done all the compute intensive work under read lock
760
     * do all the updating under a write lock
761
     */
762
0
    if (!CRYPTO_THREAD_write_lock(const_x->lock))
763
0
        return 0;
764
0
    ((X509 *)const_x)->ex_flags = tmp_ex_flags;
765
0
    ((X509 *)const_x)->ex_pathlen = tmp_ex_pathlen;
766
0
    ((X509 *)const_x)->ex_pcpathlen = tmp_ex_pcpathlen;
767
0
    if (!(tmp_ex_flags & EXFLAG_NO_FINGERPRINT))
768
0
        memcpy(((X509 *)const_x)->sha1_hash, tmp_sha1_hash, SHA_DIGEST_LENGTH);
769
0
    if (tmp_ex_flags & EXFLAG_KUSAGE)
770
0
        ((X509 *)const_x)->ex_kusage = tmp_ex_kusage;
771
0
    ((X509 *)const_x)->ex_xkusage = tmp_ex_xkusage;
772
0
    if (tmp_ex_flags & EXFLAG_NSCERT)
773
0
        ((X509 *)const_x)->ex_nscert = tmp_ex_nscert;
774
0
    ASN1_OCTET_STRING_free(((X509 *)const_x)->skid);
775
0
    ((X509 *)const_x)->skid = tmp_skid;
776
0
    AUTHORITY_KEYID_free(((X509 *)const_x)->akid);
777
0
    ((X509 *)const_x)->akid = tmp_akid;
778
0
    sk_GENERAL_NAME_pop_free(((X509 *)const_x)->altname, GENERAL_NAME_free);
779
0
    ((X509 *)const_x)->altname = tmp_altname;
780
0
    NAME_CONSTRAINTS_free(((X509 *)const_x)->nc);
781
0
    ((X509 *)const_x)->nc = tmp_nc;
782
0
    sk_DIST_POINT_pop_free(((X509 *)const_x)->crldp, DIST_POINT_free);
783
0
    ((X509 *)const_x)->crldp = tmp_crldp;
784
0
#ifndef OPENSSL_NO_RFC3779
785
0
    sk_IPAddressFamily_pop_free(((X509 *)const_x)->rfc3779_addr, IPAddressFamily_free);
786
0
    ((X509 *)const_x)->rfc3779_addr = tmp_rfc3779_addr;
787
0
    ASIdentifiers_free(((X509 *)const_x)->rfc3779_asid);
788
0
    ((X509 *)const_x)->rfc3779_asid = tmp_rfc3779_asid;
789
0
#endif
790
0
    ((X509 *)const_x)->siginf = tmp_siginf;
791
792
0
#ifdef tsan_st_rel
793
0
    tsan_st_rel((TSAN_QUALIFIER int *)&const_x->ex_cached, 1);
794
    /*
795
     * Above store triggers fast lock-free check in the beginning of the
796
     * function. But one has to ensure that the structure is "stable", i.e.
797
     * all stores are visible on all processors. Hence the release fence.
798
     */
799
0
#endif
800
0
    CRYPTO_THREAD_unlock(const_x->lock);
801
0
    if (tmp_ex_flags & EXFLAG_INVALID) {
802
0
        ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_CERTIFICATE);
803
0
        return 0;
804
0
    }
805
0
    return 1;
806
0
}
807
808
/*-
809
 * CA checks common to all purposes
810
 * return codes:
811
 * 0 not a CA
812
 * 1 is a CA
813
 * 2 Only possible in older versions of openSSL when basicConstraints are absent
814
 *   new versions will not return this value. May be a CA
815
 * 3 basicConstraints absent but self-signed V1.
816
 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
817
 * 5 Netscape specific CA Flags present
818
 */
819
820
static int check_ca(const X509 *x)
821
0
{
822
    /* keyUsage if present should allow cert signing */
823
0
    if (ku_reject(x, KU_KEY_CERT_SIGN))
824
0
        return 0;
825
0
    if ((x->ex_flags & EXFLAG_BCONS) != 0) {
826
        /* If basicConstraints says not a CA then say so */
827
0
        return (x->ex_flags & EXFLAG_CA) != 0;
828
0
    } else {
829
        /* We support V1 roots for...  uh, I don't really know why. */
830
0
        if ((x->ex_flags & V1_ROOT) == V1_ROOT)
831
0
            return 3;
832
        /*
833
         * If key usage present it must have certSign so tolerate it
834
         */
835
0
        else if ((x->ex_flags & EXFLAG_KUSAGE) != 0)
836
0
            return 4;
837
        /* Older certificates could have Netscape-specific CA types */
838
0
        else if ((x->ex_flags & EXFLAG_NSCERT) != 0
839
0
            && (x->ex_nscert & NS_ANY_CA) != 0)
840
0
            return 5;
841
        /* Can this still be regarded a CA certificate?  I doubt it. */
842
0
        return 0;
843
0
    }
844
0
}
845
846
void X509_set_proxy_flag(X509 *x)
847
0
{
848
0
    if (CRYPTO_THREAD_write_lock(x->lock)) {
849
0
        x->ex_flags |= EXFLAG_PROXY;
850
0
        CRYPTO_THREAD_unlock(x->lock);
851
0
    }
852
0
}
853
854
void X509_set_proxy_pathlen(X509 *x, long l)
855
0
{
856
0
    x->ex_pcpathlen = l;
857
0
}
858
859
int X509_check_ca(const X509 *x)
860
0
{
861
    /* Note 0 normally means "not a CA" - but in this case means error. */
862
0
    if (!ossl_x509v3_cache_extensions(x))
863
0
        return 0;
864
865
0
    return check_ca(x);
866
0
}
867
868
/* Check SSL CA: common checks for SSL client and server. */
869
static int check_ssl_ca(const X509 *x)
870
0
{
871
0
    int ca_ret = check_ca(x);
872
873
0
    if (ca_ret == 0)
874
0
        return 0;
875
    /* Check nsCertType if present */
876
0
    return ca_ret != 5 || (x->ex_nscert & NS_SSL_CA) != 0;
877
0
}
878
879
static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
880
    int non_leaf)
881
0
{
882
0
    if (xku_reject(x, XKU_SSL_CLIENT))
883
0
        return 0;
884
0
    if (non_leaf)
885
0
        return check_ssl_ca(x);
886
    /* We need to do digital signatures or key agreement */
887
0
    if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
888
0
        return 0;
889
    /* nsCertType if present should allow SSL client use */
890
0
    if (ns_reject(x, NS_SSL_CLIENT))
891
0
        return 0;
892
0
    return 1;
893
0
}
894
895
/*
896
 * Key usage needed for TLS/SSL server: digital signature, encipherment or
897
 * key agreement. The ssl code can check this more thoroughly for individual
898
 * key types.
899
 */
900
#define KU_TLS \
901
    KU_DIGITAL_SIGNATURE | KU_KEY_ENCIPHERMENT | KU_KEY_AGREEMENT
902
903
static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
904
    int non_leaf)
905
0
{
906
0
    if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
907
0
        return 0;
908
0
    if (non_leaf)
909
0
        return check_ssl_ca(x);
910
911
0
    if (ns_reject(x, NS_SSL_SERVER))
912
0
        return 0;
913
0
    if (ku_reject(x, KU_TLS))
914
0
        return 0;
915
916
0
    return 1;
917
0
}
918
919
static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
920
    int non_leaf)
921
0
{
922
0
    int ret = check_purpose_ssl_server(xp, x, non_leaf);
923
924
0
    if (!ret || non_leaf)
925
0
        return ret;
926
    /* We need to encipher or Netscape complains */
927
0
    return ku_reject(x, KU_KEY_ENCIPHERMENT) ? 0 : ret;
928
0
}
929
930
/* common S/MIME client checks */
931
static int purpose_smime(const X509 *x, int non_leaf)
932
0
{
933
0
    if (xku_reject(x, XKU_SMIME))
934
0
        return 0;
935
0
    if (non_leaf) {
936
0
        int ca_ret = check_ca(x);
937
938
0
        if (ca_ret == 0)
939
0
            return 0;
940
        /* Check nsCertType if present */
941
0
        if (ca_ret != 5 || (x->ex_nscert & NS_SMIME_CA) != 0)
942
0
            return ca_ret;
943
0
        else
944
0
            return 0;
945
0
    }
946
0
    if ((x->ex_flags & EXFLAG_NSCERT) != 0) {
947
0
        if ((x->ex_nscert & NS_SMIME) != 0)
948
0
            return 1;
949
        /* Workaround for some buggy certificates */
950
0
        return (x->ex_nscert & NS_SSL_CLIENT) != 0 ? 2 : 0;
951
0
    }
952
0
    return 1;
953
0
}
954
955
static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
956
    int non_leaf)
957
0
{
958
0
    int ret = purpose_smime(x, non_leaf);
959
960
0
    if (!ret || non_leaf)
961
0
        return ret;
962
0
    return ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION) ? 0 : ret;
963
0
}
964
965
static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
966
    int non_leaf)
967
0
{
968
0
    int ret = purpose_smime(x, non_leaf);
969
970
0
    if (!ret || non_leaf)
971
0
        return ret;
972
0
    return ku_reject(x, KU_KEY_ENCIPHERMENT) ? 0 : ret;
973
0
}
974
975
static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
976
    int non_leaf)
977
0
{
978
0
    if (non_leaf) {
979
0
        int ca_ret = check_ca(x);
980
981
0
        return ca_ret == 2 ? 0 : ca_ret;
982
0
    }
983
0
    return !ku_reject(x, KU_CRL_SIGN);
984
0
}
985
986
/*
987
 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
988
 * is valid. Additional checks must be made on the chain.
989
 */
990
static int check_purpose_ocsp_helper(const X509_PURPOSE *xp, const X509 *x,
991
    int non_leaf)
992
0
{
993
    /*
994
     * Must be a valid CA.  Should we really support the "I don't know" value
995
     * (2)?
996
     */
997
0
    if (non_leaf)
998
0
        return check_ca(x);
999
    /* Leaf certificate is checked in OCSP_basic_verify() */
1000
0
    return 1;
1001
0
}
1002
1003
static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
1004
    int non_leaf)
1005
0
{
1006
0
    int i_ext;
1007
1008
    /*
1009
     * If non_leaf is true we must check if this is a valid CA certificate.
1010
     * The extra requirements by the CA/Browser Forum are not checked.
1011
     */
1012
0
    if (non_leaf)
1013
0
        return check_ca(x);
1014
1015
    /*
1016
     * Key Usage is checked according to RFC 5280 and
1017
     * Extended Key Usage attributes is checked according to RFC 3161.
1018
     * The extra (and somewhat conflicting) CA/Browser Forum
1019
     * Baseline Requirements for the Issuance and Management of
1020
     * Publicly‐Trusted Code Signing Certificates, Version 3.0.0,
1021
     * Section 7.1.2.3: Code signing and Timestamp Certificate are not checked.
1022
     */
1023
    /*
1024
     * Check the optional key usage field:
1025
     * if Key Usage is present, it must be one of digitalSignature
1026
     * and/or nonRepudiation (other values are not consistent and shall
1027
     * be rejected).
1028
     */
1029
0
    if ((x->ex_flags & EXFLAG_KUSAGE) != 0
1030
0
        && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) || !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
1031
0
        return 0;
1032
1033
    /* Only timestamp key usage is permitted and it's required. */
1034
0
    if ((x->ex_flags & EXFLAG_XKUSAGE) == 0 || x->ex_xkusage != XKU_TIMESTAMP)
1035
0
        return 0;
1036
1037
    /* Extended Key Usage MUST be critical */
1038
0
    i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
1039
0
    if (i_ext >= 0
1040
0
        && !X509_EXTENSION_get_critical(X509_get_ext((X509 *)x, i_ext)))
1041
0
        return 0;
1042
0
    return 1;
1043
0
}
1044
1045
static int check_purpose_code_sign(const X509_PURPOSE *xp, const X509 *x,
1046
    int non_leaf)
1047
0
{
1048
0
    int i_ext;
1049
1050
    /*
1051
     * If non_leaf is true we must check if this is a valid CA certificate.
1052
     * The extra requirements by the CA/Browser Forum are not checked.
1053
     */
1054
0
    if (non_leaf)
1055
0
        return check_ca(x);
1056
1057
    /*
1058
     * Check the key usage and extended key usage fields:
1059
     *
1060
     * Reference: CA/Browser Forum,
1061
     * Baseline Requirements for the Issuance and Management of
1062
     * Publicly‐Trusted Code Signing Certificates, Version 3.0.0,
1063
     * Section 7.1.2.3: Code signing and Timestamp Certificate
1064
     *
1065
     * Checking covers Key Usage and Extended Key Usage attributes.
1066
     * The certificatePolicies, cRLDistributionPoints (CDP), and
1067
     * authorityInformationAccess (AIA) extensions are so far not checked.
1068
     */
1069
    /* Key Usage */
1070
0
    if ((x->ex_flags & EXFLAG_KUSAGE) == 0)
1071
0
        return 0;
1072
0
    if ((x->ex_kusage & KU_DIGITAL_SIGNATURE) == 0)
1073
0
        return 0;
1074
0
    if ((x->ex_kusage & (KU_KEY_CERT_SIGN | KU_CRL_SIGN)) != 0)
1075
0
        return 0;
1076
1077
    /* Key Usage MUST be critical */
1078
0
    i_ext = X509_get_ext_by_NID(x, NID_key_usage, -1);
1079
0
    if (i_ext < 0)
1080
0
        return 0;
1081
0
    if (i_ext >= 0) {
1082
0
        const X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
1083
0
        if (!X509_EXTENSION_get_critical(ext))
1084
0
            return 0;
1085
0
    }
1086
1087
    /* Extended Key Usage */
1088
0
    if ((x->ex_flags & EXFLAG_XKUSAGE) == 0)
1089
0
        return 0;
1090
0
    if ((x->ex_xkusage & XKU_CODE_SIGN) == 0)
1091
0
        return 0;
1092
0
    if ((x->ex_xkusage & (XKU_ANYEKU | XKU_SSL_SERVER)) != 0)
1093
0
        return 0;
1094
1095
0
    return 1;
1096
0
}
1097
1098
static int no_check_purpose(const X509_PURPOSE *xp, const X509 *x,
1099
    int non_leaf)
1100
0
{
1101
0
    return 1;
1102
0
}
1103
1104
/*-
1105
 * Various checks to see if one certificate potentially issued the second.
1106
 * This can be used to prune a set of possible issuer certificates which
1107
 * have been looked up using some simple method such as by subject name.
1108
 * These are:
1109
 * 1. issuer_name(subject) == subject_name(issuer)
1110
 * 2. If akid(subject) exists, it matches the respective issuer fields.
1111
 * 3. subject signature algorithm == issuer public key algorithm
1112
 * 4. If key_usage(issuer) exists, it allows for signing subject.
1113
 * Note that this does not include actually checking the signature.
1114
 * Returns 0 for OK, or positive for reason for mismatch
1115
 * where reason codes match those for X509_verify_cert().
1116
 */
1117
int X509_check_issued(const X509 *issuer, const X509 *subject)
1118
0
{
1119
0
    int ret;
1120
1121
0
    if ((ret = ossl_x509_likely_issued(issuer, subject)) != X509_V_OK)
1122
0
        return ret;
1123
0
    return ossl_x509_signing_allowed(issuer, subject);
1124
0
}
1125
1126
/*
1127
 * Do the checks 1., 2., and 3. as described above for X509_check_issued().
1128
 * These are very similar to a section of ossl_x509v3_cache_extensions().
1129
 * If |issuer| equals |subject| (such that self-signature should be checked),
1130
 * use the EXFLAG_SS result of ossl_x509v3_cache_extensions().
1131
 */
1132
int ossl_x509_likely_issued(const X509 *issuer, const X509 *subject)
1133
0
{
1134
0
    int ret;
1135
1136
0
    if (X509_NAME_cmp(X509_get_subject_name(issuer),
1137
0
            X509_get_issuer_name(subject))
1138
0
        != 0)
1139
0
        return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
1140
1141
    /* set issuer->skid, subject->akid, and subject->ex_flags */
1142
0
    if (!ossl_x509v3_cache_extensions(issuer)
1143
0
        || !ossl_x509v3_cache_extensions(subject))
1144
0
        return X509_V_ERR_UNSPECIFIED;
1145
1146
0
    if (issuer == subject
1147
0
        || (X509_NAME_cmp(X509_get_issuer_name(issuer), X509_get_issuer_name(subject)) == 0
1148
0
            && ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), X509_get0_serialNumber(subject)) == 0))
1149
        /*
1150
         * At this point, we can assume that issuer and subject
1151
         * are semantically the same cert because they are identical
1152
         * or at least have the same issuer and serial number,
1153
         * which (for any sane cert issuer) implies equality of the two certs.
1154
         * In this case, for consistency with chain building and validation,
1155
         * we make our issuance judgment depend on the presence of EXFLAG_SS.
1156
         * This is used for corrected chain building in the corner case of
1157
         * a self-issued but not actually self-signed trust anchor cert
1158
         * without subject and issuer key identifiers (i.e., no SKID and AKID).
1159
         */
1160
0
        return (issuer->ex_flags & EXFLAG_SS) != 0
1161
0
            ? X509_V_OK
1162
0
            : X509_V_ERR_CERT_SIGNATURE_FAILURE;
1163
1164
0
    ret = X509_check_akid(issuer, subject->akid);
1165
0
    if (ret != X509_V_OK)
1166
0
        return ret;
1167
1168
    /* Check if the subject signature alg matches the issuer's PUBKEY alg */
1169
0
    return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
1170
0
}
1171
1172
/*-
1173
 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
1174
 * according to the B<keyUsage> field of I<issuer> if present
1175
 * depending on any proxyCertInfo extension of I<subject>.
1176
 * Returns 0 for OK, or positive for reason for rejection
1177
 * where reason codes match those for X509_verify_cert().
1178
 */
1179
int ossl_x509_signing_allowed(const X509 *issuer, const X509 *subject)
1180
0
{
1181
0
    if ((subject->ex_flags & EXFLAG_PROXY) != 0) {
1182
0
        if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
1183
0
            return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
1184
0
    } else if (ku_reject(issuer, KU_KEY_CERT_SIGN)) {
1185
0
        return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
1186
0
    }
1187
0
    return X509_V_OK;
1188
0
}
1189
1190
/*
1191
 * check if all sub-fields of the authority key identifier information akid,
1192
 * as far as present, match the respective subjectKeyIdentifier extension (if
1193
 * present in issuer), serialNumber field, and issuer fields of issuer.
1194
 * returns X509_V_OK also if akid is NULL because this means no restriction.
1195
 */
1196
int X509_check_akid(const X509 *issuer, const AUTHORITY_KEYID *akid)
1197
0
{
1198
0
    if (akid == NULL)
1199
0
        return X509_V_OK;
1200
1201
    /* Check key ids (if present) */
1202
0
    if (akid->keyid && issuer->skid && ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
1203
0
        return X509_V_ERR_AKID_SKID_MISMATCH;
1204
    /* Check serial number */
1205
0
    if (akid->serial && ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), akid->serial))
1206
0
        return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
1207
    /* Check issuer name */
1208
0
    if (akid->issuer) {
1209
        /*
1210
         * Ugh, for some peculiar reason AKID includes SEQUENCE OF
1211
         * GeneralName. So look for a DirName. There may be more than one but
1212
         * we only take any notice of the first.
1213
         */
1214
0
        GENERAL_NAMES *gens = akid->issuer;
1215
0
        GENERAL_NAME *gen;
1216
0
        X509_NAME *nm = NULL;
1217
0
        int i;
1218
1219
0
        for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
1220
0
            gen = sk_GENERAL_NAME_value(gens, i);
1221
0
            if (gen->type == GEN_DIRNAME) {
1222
0
                nm = gen->d.dirn;
1223
0
                break;
1224
0
            }
1225
0
        }
1226
0
        if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0)
1227
0
            return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
1228
0
    }
1229
0
    return X509_V_OK;
1230
0
}
1231
1232
uint32_t X509_get_extension_flags(const X509 *x)
1233
0
{
1234
    /* Call for side-effect of computing hash and caching extensions */
1235
0
    X509_check_purpose(x, -1, 0);
1236
0
    return x->ex_flags;
1237
0
}
1238
1239
uint32_t X509_get_key_usage(const X509 *x)
1240
0
{
1241
    /* Call for side-effect of computing hash and caching extensions */
1242
0
    if (X509_check_purpose(x, -1, 0) != 1)
1243
0
        return 0;
1244
0
    return (x->ex_flags & EXFLAG_KUSAGE) != 0 ? x->ex_kusage : UINT32_MAX;
1245
0
}
1246
1247
uint32_t X509_get_extended_key_usage(const X509 *x)
1248
0
{
1249
    /* Call for side-effect of computing hash and caching extensions */
1250
0
    if (X509_check_purpose(x, -1, 0) != 1)
1251
0
        return 0;
1252
0
    return (x->ex_flags & EXFLAG_XKUSAGE) != 0 ? x->ex_xkusage : UINT32_MAX;
1253
0
}
1254
1255
const ASN1_OCTET_STRING *X509_get0_subject_key_id(const X509 *x)
1256
0
{
1257
    /* Call for side-effect of computing hash and caching extensions */
1258
0
    if (X509_check_purpose(x, -1, 0) != 1)
1259
0
        return NULL;
1260
0
    return x->skid;
1261
0
}
1262
1263
const ASN1_OCTET_STRING *X509_get0_authority_key_id(const X509 *x)
1264
0
{
1265
    /* Call for side-effect of computing hash and caching extensions */
1266
0
    if (X509_check_purpose(x, -1, 0) != 1)
1267
0
        return NULL;
1268
0
    return (x->akid != NULL ? x->akid->keyid : NULL);
1269
0
}
1270
1271
const GENERAL_NAMES *X509_get0_authority_issuer(const X509 *x)
1272
0
{
1273
    /* Call for side-effect of computing hash and caching extensions */
1274
0
    if (X509_check_purpose(x, -1, 0) != 1)
1275
0
        return NULL;
1276
0
    return (x->akid != NULL ? x->akid->issuer : NULL);
1277
0
}
1278
1279
const ASN1_INTEGER *X509_get0_authority_serial(const X509 *x)
1280
0
{
1281
    /* Call for side-effect of computing hash and caching extensions */
1282
0
    if (X509_check_purpose(x, -1, 0) != 1)
1283
0
        return NULL;
1284
0
    return (x->akid != NULL ? x->akid->serial : NULL);
1285
0
}
1286
1287
long X509_get_pathlen(const X509 *x)
1288
0
{
1289
    /* Called for side effect of caching extensions */
1290
0
    if (X509_check_purpose(x, -1, 0) != 1
1291
0
        || (x->ex_flags & EXFLAG_BCONS) == 0)
1292
0
        return -1;
1293
0
    return x->ex_pathlen;
1294
0
}
1295
1296
long X509_get_proxy_pathlen(const X509 *x)
1297
0
{
1298
    /* Called for side effect of caching extensions */
1299
0
    if (X509_check_purpose(x, -1, 0) != 1
1300
0
        || (x->ex_flags & EXFLAG_PROXY) == 0)
1301
0
        return -1;
1302
0
    return x->ex_pcpathlen;
1303
0
}