Coverage Report

Created: 2025-06-13 06:58

/src/openssl32/crypto/ec/ec_pmeth.c
Line
Count
Source (jump to first uncovered line)
1
/*
2
 * Copyright 2006-2021 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
/*
11
 * ECDH and ECDSA low level APIs are deprecated for public use, but still ok
12
 * for internal use.
13
 */
14
#include "internal/deprecated.h"
15
16
#include <stdio.h>
17
#include "internal/cryptlib.h"
18
#include <openssl/asn1t.h>
19
#include <openssl/x509.h>
20
#include <openssl/ec.h>
21
#include "ec_local.h"
22
#include <openssl/evp.h>
23
#include "crypto/evp.h"
24
25
/* EC pkey context structure */
26
27
typedef struct {
28
    /* Key and paramgen group */
29
    EC_GROUP *gen_group;
30
    /* message digest */
31
    const EVP_MD *md;
32
    /* Duplicate key if custom cofactor needed */
33
    EC_KEY *co_key;
34
    /* Cofactor mode */
35
    signed char cofactor_mode;
36
    /* KDF (if any) to use for ECDH */
37
    char kdf_type;
38
    /* Message digest to use for key derivation */
39
    const EVP_MD *kdf_md;
40
    /* User key material */
41
    unsigned char *kdf_ukm;
42
    size_t kdf_ukmlen;
43
    /* KDF output length */
44
    size_t kdf_outlen;
45
} EC_PKEY_CTX;
46
47
static int pkey_ec_init(EVP_PKEY_CTX *ctx)
48
0
{
49
0
    EC_PKEY_CTX *dctx;
50
51
0
    if ((dctx = OPENSSL_zalloc(sizeof(*dctx))) == NULL)
52
0
        return 0;
53
54
0
    dctx->cofactor_mode = -1;
55
0
    dctx->kdf_type = EVP_PKEY_ECDH_KDF_NONE;
56
0
    ctx->data = dctx;
57
0
    return 1;
58
0
}
59
60
static int pkey_ec_copy(EVP_PKEY_CTX *dst, const EVP_PKEY_CTX *src)
61
0
{
62
0
    EC_PKEY_CTX *dctx, *sctx;
63
0
    if (!pkey_ec_init(dst))
64
0
        return 0;
65
0
    sctx = src->data;
66
0
    dctx = dst->data;
67
0
    if (sctx->gen_group) {
68
0
        dctx->gen_group = EC_GROUP_dup(sctx->gen_group);
69
0
        if (!dctx->gen_group)
70
0
            return 0;
71
0
    }
72
0
    dctx->md = sctx->md;
73
74
0
    if (sctx->co_key) {
75
0
        dctx->co_key = EC_KEY_dup(sctx->co_key);
76
0
        if (!dctx->co_key)
77
0
            return 0;
78
0
    }
79
0
    dctx->kdf_type = sctx->kdf_type;
80
0
    dctx->kdf_md = sctx->kdf_md;
81
0
    dctx->kdf_outlen = sctx->kdf_outlen;
82
0
    if (sctx->kdf_ukm) {
83
0
        dctx->kdf_ukm = OPENSSL_memdup(sctx->kdf_ukm, sctx->kdf_ukmlen);
84
0
        if (!dctx->kdf_ukm)
85
0
            return 0;
86
0
    } else
87
0
        dctx->kdf_ukm = NULL;
88
0
    dctx->kdf_ukmlen = sctx->kdf_ukmlen;
89
0
    return 1;
90
0
}
91
92
static void pkey_ec_cleanup(EVP_PKEY_CTX *ctx)
93
0
{
94
0
    EC_PKEY_CTX *dctx = ctx->data;
95
0
    if (dctx != NULL) {
96
0
        EC_GROUP_free(dctx->gen_group);
97
0
        EC_KEY_free(dctx->co_key);
98
0
        OPENSSL_free(dctx->kdf_ukm);
99
0
        OPENSSL_free(dctx);
100
0
        ctx->data = NULL;
101
0
    }
102
0
}
103
104
static int pkey_ec_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
105
                        const unsigned char *tbs, size_t tbslen)
106
0
{
107
0
    int ret, type;
108
0
    unsigned int sltmp;
109
0
    EC_PKEY_CTX *dctx = ctx->data;
110
    /*
111
     * Discard const. Its marked as const because this may be a cached copy of
112
     * the "real" key. These calls don't make any modifications that need to
113
     * be reflected back in the "original" key.
114
     */
115
0
    EC_KEY *ec = (EC_KEY *)EVP_PKEY_get0_EC_KEY(ctx->pkey);
116
0
    const int sig_sz = ECDSA_size(ec);
117
118
    /* ensure cast to size_t is safe */
119
0
    if (!ossl_assert(sig_sz > 0))
120
0
        return 0;
121
122
0
    if (sig == NULL) {
123
0
        *siglen = (size_t)sig_sz;
124
0
        return 1;
125
0
    }
126
127
0
    if (*siglen < (size_t)sig_sz) {
128
0
        ERR_raise(ERR_LIB_EC, EC_R_BUFFER_TOO_SMALL);
129
0
        return 0;
130
0
    }
131
132
0
    type = (dctx->md != NULL) ? EVP_MD_get_type(dctx->md) : NID_sha1;
133
134
0
    ret = ECDSA_sign(type, tbs, tbslen, sig, &sltmp, ec);
135
136
0
    if (ret <= 0)
137
0
        return ret;
138
0
    *siglen = (size_t)sltmp;
139
0
    return 1;
140
0
}
141
142
static int pkey_ec_verify(EVP_PKEY_CTX *ctx,
143
                          const unsigned char *sig, size_t siglen,
144
                          const unsigned char *tbs, size_t tbslen)
145
0
{
146
0
    int ret, type;
147
0
    EC_PKEY_CTX *dctx = ctx->data;
148
    /*
149
     * Discard const. Its marked as const because this may be a cached copy of
150
     * the "real" key. These calls don't make any modifications that need to
151
     * be reflected back in the "original" key.
152
     */
153
0
    EC_KEY *ec = (EC_KEY *)EVP_PKEY_get0_EC_KEY(ctx->pkey);
154
155
0
    if (dctx->md)
156
0
        type = EVP_MD_get_type(dctx->md);
157
0
    else
158
0
        type = NID_sha1;
159
160
0
    ret = ECDSA_verify(type, tbs, tbslen, sig, siglen, ec);
161
162
0
    return ret;
163
0
}
164
165
#ifndef OPENSSL_NO_EC
166
static int pkey_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
167
0
{
168
0
    int ret;
169
0
    size_t outlen;
170
0
    const EC_POINT *pubkey = NULL;
171
0
    EC_KEY *eckey;
172
0
    const EC_KEY *eckeypub;
173
0
    EC_PKEY_CTX *dctx = ctx->data;
174
175
0
    if (ctx->pkey == NULL || ctx->peerkey == NULL) {
176
0
        ERR_raise(ERR_LIB_EC, EC_R_KEYS_NOT_SET);
177
0
        return 0;
178
0
    }
179
0
    eckeypub = EVP_PKEY_get0_EC_KEY(ctx->peerkey);
180
0
    if (eckeypub == NULL) {
181
0
        ERR_raise(ERR_LIB_EC, EC_R_KEYS_NOT_SET);
182
0
        return 0;
183
0
    }
184
185
0
    eckey = dctx->co_key ? dctx->co_key
186
0
                         : (EC_KEY *)EVP_PKEY_get0_EC_KEY(ctx->pkey);
187
188
0
    if (!key) {
189
0
        const EC_GROUP *group;
190
0
        group = EC_KEY_get0_group(eckey);
191
192
0
        if (group == NULL)
193
0
            return 0;
194
0
        *keylen = (EC_GROUP_get_degree(group) + 7) / 8;
195
0
        return 1;
196
0
    }
197
0
    pubkey = EC_KEY_get0_public_key(eckeypub);
198
199
    /*
200
     * NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is not
201
     * an error, the result is truncated.
202
     */
203
204
0
    outlen = *keylen;
205
206
0
    ret = ECDH_compute_key(key, outlen, pubkey, eckey, 0);
207
0
    if (ret <= 0)
208
0
        return 0;
209
0
    *keylen = ret;
210
0
    return 1;
211
0
}
212
213
static int pkey_ec_kdf_derive(EVP_PKEY_CTX *ctx,
214
                              unsigned char *key, size_t *keylen)
215
0
{
216
0
    EC_PKEY_CTX *dctx = ctx->data;
217
0
    unsigned char *ktmp = NULL;
218
0
    size_t ktmplen;
219
0
    int rv = 0;
220
0
    if (dctx->kdf_type == EVP_PKEY_ECDH_KDF_NONE)
221
0
        return pkey_ec_derive(ctx, key, keylen);
222
0
    if (!key) {
223
0
        *keylen = dctx->kdf_outlen;
224
0
        return 1;
225
0
    }
226
0
    if (*keylen != dctx->kdf_outlen)
227
0
        return 0;
228
0
    if (!pkey_ec_derive(ctx, NULL, &ktmplen))
229
0
        return 0;
230
0
    if ((ktmp = OPENSSL_malloc(ktmplen)) == NULL)
231
0
        return 0;
232
0
    if (!pkey_ec_derive(ctx, ktmp, &ktmplen))
233
0
        goto err;
234
    /* Do KDF stuff */
235
0
    if (!ossl_ecdh_kdf_X9_63(key, *keylen, ktmp, ktmplen,
236
0
                             dctx->kdf_ukm, dctx->kdf_ukmlen, dctx->kdf_md,
237
0
                             ctx->libctx, ctx->propquery))
238
0
        goto err;
239
0
    rv = 1;
240
241
0
 err:
242
0
    OPENSSL_clear_free(ktmp, ktmplen);
243
0
    return rv;
244
0
}
245
#endif
246
247
static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
248
0
{
249
0
    EC_PKEY_CTX *dctx = ctx->data;
250
0
    EC_GROUP *group;
251
0
    switch (type) {
252
0
    case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
253
0
        group = EC_GROUP_new_by_curve_name(p1);
254
0
        if (group == NULL) {
255
0
            ERR_raise(ERR_LIB_EC, EC_R_INVALID_CURVE);
256
0
            return 0;
257
0
        }
258
0
        EC_GROUP_free(dctx->gen_group);
259
0
        dctx->gen_group = group;
260
0
        return 1;
261
262
0
    case EVP_PKEY_CTRL_EC_PARAM_ENC:
263
0
        if (!dctx->gen_group) {
264
0
            ERR_raise(ERR_LIB_EC, EC_R_NO_PARAMETERS_SET);
265
0
            return 0;
266
0
        }
267
0
        EC_GROUP_set_asn1_flag(dctx->gen_group, p1);
268
0
        return 1;
269
270
0
#ifndef OPENSSL_NO_EC
271
0
    case EVP_PKEY_CTRL_EC_ECDH_COFACTOR:
272
0
        if (p1 == -2) {
273
0
            if (dctx->cofactor_mode != -1)
274
0
                return dctx->cofactor_mode;
275
0
            else {
276
0
                const EC_KEY *ec_key = EVP_PKEY_get0_EC_KEY(ctx->pkey);
277
0
                return EC_KEY_get_flags(ec_key) & EC_FLAG_COFACTOR_ECDH ? 1 : 0;
278
0
            }
279
0
        } else if (p1 < -1 || p1 > 1)
280
0
            return -2;
281
0
        dctx->cofactor_mode = p1;
282
0
        if (p1 != -1) {
283
0
            EC_KEY *ec_key = (EC_KEY *)EVP_PKEY_get0_EC_KEY(ctx->pkey);
284
285
            /*
286
             * We discarded the "const" above. This will only work if the key is
287
             * a "real" legacy key, and not a cached copy of a provided key
288
             */
289
0
            if (evp_pkey_is_provided(ctx->pkey)) {
290
0
                ERR_raise(ERR_LIB_EC, ERR_R_UNSUPPORTED);
291
0
                return 0;
292
0
            }
293
0
            if (!ec_key->group)
294
0
                return -2;
295
            /* If cofactor is 1 cofactor mode does nothing */
296
0
            if (BN_is_one(ec_key->group->cofactor))
297
0
                return 1;
298
0
            if (!dctx->co_key) {
299
0
                dctx->co_key = EC_KEY_dup(ec_key);
300
0
                if (!dctx->co_key)
301
0
                    return 0;
302
0
            }
303
0
            if (p1)
304
0
                EC_KEY_set_flags(dctx->co_key, EC_FLAG_COFACTOR_ECDH);
305
0
            else
306
0
                EC_KEY_clear_flags(dctx->co_key, EC_FLAG_COFACTOR_ECDH);
307
0
        } else {
308
0
            EC_KEY_free(dctx->co_key);
309
0
            dctx->co_key = NULL;
310
0
        }
311
0
        return 1;
312
0
#endif
313
314
0
    case EVP_PKEY_CTRL_EC_KDF_TYPE:
315
0
        if (p1 == -2)
316
0
            return dctx->kdf_type;
317
0
        if (p1 != EVP_PKEY_ECDH_KDF_NONE && p1 != EVP_PKEY_ECDH_KDF_X9_63)
318
0
            return -2;
319
0
        dctx->kdf_type = p1;
320
0
        return 1;
321
322
0
    case EVP_PKEY_CTRL_EC_KDF_MD:
323
0
        dctx->kdf_md = p2;
324
0
        return 1;
325
326
0
    case EVP_PKEY_CTRL_GET_EC_KDF_MD:
327
0
        *(const EVP_MD **)p2 = dctx->kdf_md;
328
0
        return 1;
329
330
0
    case EVP_PKEY_CTRL_EC_KDF_OUTLEN:
331
0
        if (p1 <= 0)
332
0
            return -2;
333
0
        dctx->kdf_outlen = (size_t)p1;
334
0
        return 1;
335
336
0
    case EVP_PKEY_CTRL_GET_EC_KDF_OUTLEN:
337
0
        *(int *)p2 = dctx->kdf_outlen;
338
0
        return 1;
339
340
0
    case EVP_PKEY_CTRL_EC_KDF_UKM:
341
0
        OPENSSL_free(dctx->kdf_ukm);
342
0
        dctx->kdf_ukm = p2;
343
0
        if (p2)
344
0
            dctx->kdf_ukmlen = p1;
345
0
        else
346
0
            dctx->kdf_ukmlen = 0;
347
0
        return 1;
348
349
0
    case EVP_PKEY_CTRL_GET_EC_KDF_UKM:
350
0
        *(unsigned char **)p2 = dctx->kdf_ukm;
351
0
        return dctx->kdf_ukmlen;
352
353
0
    case EVP_PKEY_CTRL_MD:
354
0
        if (EVP_MD_get_type((const EVP_MD *)p2) != NID_sha1 &&
355
0
            EVP_MD_get_type((const EVP_MD *)p2) != NID_ecdsa_with_SHA1 &&
356
0
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha224 &&
357
0
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha256 &&
358
0
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha384 &&
359
0
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha512 &&
360
0
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_224 &&
361
0
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_256 &&
362
0
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_384 &&
363
0
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_512 &&
364
0
            EVP_MD_get_type((const EVP_MD *)p2) != NID_sm3) {
365
0
            ERR_raise(ERR_LIB_EC, EC_R_INVALID_DIGEST_TYPE);
366
0
            return 0;
367
0
        }
368
0
        dctx->md = p2;
369
0
        return 1;
370
371
0
    case EVP_PKEY_CTRL_GET_MD:
372
0
        *(const EVP_MD **)p2 = dctx->md;
373
0
        return 1;
374
375
0
    case EVP_PKEY_CTRL_PEER_KEY:
376
        /* Default behaviour is OK */
377
0
    case EVP_PKEY_CTRL_DIGESTINIT:
378
0
    case EVP_PKEY_CTRL_PKCS7_SIGN:
379
0
    case EVP_PKEY_CTRL_CMS_SIGN:
380
0
        return 1;
381
382
0
    default:
383
0
        return -2;
384
385
0
    }
386
0
}
387
388
static int pkey_ec_ctrl_str(EVP_PKEY_CTX *ctx,
389
                            const char *type, const char *value)
390
0
{
391
0
    if (strcmp(type, "ec_paramgen_curve") == 0) {
392
0
        int nid;
393
0
        nid = EC_curve_nist2nid(value);
394
0
        if (nid == NID_undef)
395
0
            nid = OBJ_sn2nid(value);
396
0
        if (nid == NID_undef)
397
0
            nid = OBJ_ln2nid(value);
398
0
        if (nid == NID_undef) {
399
0
            ERR_raise(ERR_LIB_EC, EC_R_INVALID_CURVE);
400
0
            return 0;
401
0
        }
402
0
        return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid);
403
0
    } else if (strcmp(type, "ec_param_enc") == 0) {
404
0
        int param_enc;
405
0
        if (strcmp(value, "explicit") == 0)
406
0
            param_enc = 0;
407
0
        else if (strcmp(value, "named_curve") == 0)
408
0
            param_enc = OPENSSL_EC_NAMED_CURVE;
409
0
        else
410
0
            return -2;
411
0
        return EVP_PKEY_CTX_set_ec_param_enc(ctx, param_enc);
412
0
    } else if (strcmp(type, "ecdh_kdf_md") == 0) {
413
0
        const EVP_MD *md;
414
0
        if ((md = EVP_get_digestbyname(value)) == NULL) {
415
0
            ERR_raise(ERR_LIB_EC, EC_R_INVALID_DIGEST);
416
0
            return 0;
417
0
        }
418
0
        return EVP_PKEY_CTX_set_ecdh_kdf_md(ctx, md);
419
0
    } else if (strcmp(type, "ecdh_cofactor_mode") == 0) {
420
0
        int co_mode;
421
0
        co_mode = atoi(value);
422
0
        return EVP_PKEY_CTX_set_ecdh_cofactor_mode(ctx, co_mode);
423
0
    }
424
425
0
    return -2;
426
0
}
427
428
static int pkey_ec_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
429
0
{
430
0
    EC_KEY *ec = NULL;
431
0
    EC_PKEY_CTX *dctx = ctx->data;
432
0
    int ret;
433
434
0
    if (dctx->gen_group == NULL) {
435
0
        ERR_raise(ERR_LIB_EC, EC_R_NO_PARAMETERS_SET);
436
0
        return 0;
437
0
    }
438
0
    ec = EC_KEY_new();
439
0
    if (ec == NULL)
440
0
        return 0;
441
0
    if (!(ret = EC_KEY_set_group(ec, dctx->gen_group))
442
0
        || !ossl_assert(ret = EVP_PKEY_assign_EC_KEY(pkey, ec)))
443
0
        EC_KEY_free(ec);
444
0
    return ret;
445
0
}
446
447
static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
448
0
{
449
0
    EC_KEY *ec = NULL;
450
0
    EC_PKEY_CTX *dctx = ctx->data;
451
0
    int ret;
452
453
0
    if (ctx->pkey == NULL && dctx->gen_group == NULL) {
454
0
        ERR_raise(ERR_LIB_EC, EC_R_NO_PARAMETERS_SET);
455
0
        return 0;
456
0
    }
457
0
    ec = EC_KEY_new();
458
0
    if (ec == NULL)
459
0
        return 0;
460
0
    if (!ossl_assert(EVP_PKEY_assign_EC_KEY(pkey, ec))) {
461
0
        EC_KEY_free(ec);
462
0
        return 0;
463
0
    }
464
    /* Note: if error is returned, we count on caller to free pkey->pkey.ec */
465
0
    if (ctx->pkey != NULL)
466
0
        ret = EVP_PKEY_copy_parameters(pkey, ctx->pkey);
467
0
    else
468
0
        ret = EC_KEY_set_group(ec, dctx->gen_group);
469
470
0
    return ret ? EC_KEY_generate_key(ec) : 0;
471
0
}
472
473
static const EVP_PKEY_METHOD ec_pkey_meth = {
474
    EVP_PKEY_EC,
475
    0,
476
    pkey_ec_init,
477
    pkey_ec_copy,
478
    pkey_ec_cleanup,
479
480
    0,
481
    pkey_ec_paramgen,
482
483
    0,
484
    pkey_ec_keygen,
485
486
    0,
487
    pkey_ec_sign,
488
489
    0,
490
    pkey_ec_verify,
491
492
    0, 0,
493
494
    0, 0, 0, 0,
495
496
    0,
497
    0,
498
499
    0,
500
    0,
501
502
    0,
503
#ifndef OPENSSL_NO_EC
504
    pkey_ec_kdf_derive,
505
#else
506
    0,
507
#endif
508
    pkey_ec_ctrl,
509
    pkey_ec_ctrl_str
510
};
511
512
const EVP_PKEY_METHOD *ossl_ec_pkey_method(void)
513
0
{
514
0
    return &ec_pkey_meth;
515
0
}