2 * Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved.
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
11 * ECDH and ECDSA low level APIs are deprecated for public use, but still ok
14 #include "internal/deprecated.h"
17 #include "internal/cryptlib.h"
18 #include <openssl/asn1t.h>
19 #include <openssl/x509.h>
20 #include <openssl/ec.h>
22 #include <openssl/evp.h>
23 #include "crypto/evp.h"
25 /* EC pkey context structure */
28 /* Key and paramgen group */
32 /* Duplicate key if custom cofactor needed */
35 signed char cofactor_mode;
36 /* KDF (if any) to use for ECDH */
38 /* Message digest to use for key derivation */
40 /* User key material */
41 unsigned char *kdf_ukm;
43 /* KDF output length */
47 static int pkey_ec_init(EVP_PKEY_CTX *ctx)
51 if ((dctx = OPENSSL_zalloc(sizeof(*dctx))) == NULL) {
52 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
56 dctx->cofactor_mode = -1;
57 dctx->kdf_type = EVP_PKEY_ECDH_KDF_NONE;
62 static int pkey_ec_copy(EVP_PKEY_CTX *dst, const EVP_PKEY_CTX *src)
64 EC_PKEY_CTX *dctx, *sctx;
65 if (!pkey_ec_init(dst))
69 if (sctx->gen_group) {
70 dctx->gen_group = EC_GROUP_dup(sctx->gen_group);
77 dctx->co_key = EC_KEY_dup(sctx->co_key);
81 dctx->kdf_type = sctx->kdf_type;
82 dctx->kdf_md = sctx->kdf_md;
83 dctx->kdf_outlen = sctx->kdf_outlen;
85 dctx->kdf_ukm = OPENSSL_memdup(sctx->kdf_ukm, sctx->kdf_ukmlen);
90 dctx->kdf_ukmlen = sctx->kdf_ukmlen;
94 static void pkey_ec_cleanup(EVP_PKEY_CTX *ctx)
96 EC_PKEY_CTX *dctx = ctx->data;
98 EC_GROUP_free(dctx->gen_group);
99 EC_KEY_free(dctx->co_key);
100 OPENSSL_free(dctx->kdf_ukm);
106 static int pkey_ec_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
107 const unsigned char *tbs, size_t tbslen)
111 EC_PKEY_CTX *dctx = ctx->data;
113 * Discard const. Its marked as const because this may be a cached copy of
114 * the "real" key. These calls don't make any modifications that need to
115 * be reflected back in the "original" key.
117 EC_KEY *ec = (EC_KEY *)EVP_PKEY_get0_EC_KEY(ctx->pkey);
118 const int sig_sz = ECDSA_size(ec);
120 /* ensure cast to size_t is safe */
121 if (!ossl_assert(sig_sz > 0))
125 *siglen = (size_t)sig_sz;
129 if (*siglen < (size_t)sig_sz) {
130 ERR_raise(ERR_LIB_EC, EC_R_BUFFER_TOO_SMALL);
134 type = (dctx->md != NULL) ? EVP_MD_get_type(dctx->md) : NID_sha1;
136 ret = ECDSA_sign(type, tbs, tbslen, sig, &sltmp, ec);
140 *siglen = (size_t)sltmp;
144 static int pkey_ec_verify(EVP_PKEY_CTX *ctx,
145 const unsigned char *sig, size_t siglen,
146 const unsigned char *tbs, size_t tbslen)
149 EC_PKEY_CTX *dctx = ctx->data;
151 * Discard const. Its marked as const because this may be a cached copy of
152 * the "real" key. These calls don't make any modifications that need to
153 * be reflected back in the "original" key.
155 EC_KEY *ec = (EC_KEY *)EVP_PKEY_get0_EC_KEY(ctx->pkey);
158 type = EVP_MD_get_type(dctx->md);
162 ret = ECDSA_verify(type, tbs, tbslen, sig, siglen, ec);
167 #ifndef OPENSSL_NO_EC
168 static int pkey_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
172 const EC_POINT *pubkey = NULL;
174 const EC_KEY *eckeypub;
175 EC_PKEY_CTX *dctx = ctx->data;
177 if (ctx->pkey == NULL || ctx->peerkey == NULL) {
178 ERR_raise(ERR_LIB_EC, EC_R_KEYS_NOT_SET);
181 eckeypub = EVP_PKEY_get0_EC_KEY(ctx->peerkey);
182 if (eckeypub == NULL) {
183 ERR_raise(ERR_LIB_EC, EC_R_KEYS_NOT_SET);
187 eckey = dctx->co_key ? dctx->co_key
188 : (EC_KEY *)EVP_PKEY_get0_EC_KEY(ctx->pkey);
191 const EC_GROUP *group;
192 group = EC_KEY_get0_group(eckey);
196 *keylen = (EC_GROUP_get_degree(group) + 7) / 8;
199 pubkey = EC_KEY_get0_public_key(eckeypub);
202 * NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is not
203 * an error, the result is truncated.
208 ret = ECDH_compute_key(key, outlen, pubkey, eckey, 0);
215 static int pkey_ec_kdf_derive(EVP_PKEY_CTX *ctx,
216 unsigned char *key, size_t *keylen)
218 EC_PKEY_CTX *dctx = ctx->data;
219 unsigned char *ktmp = NULL;
222 if (dctx->kdf_type == EVP_PKEY_ECDH_KDF_NONE)
223 return pkey_ec_derive(ctx, key, keylen);
225 *keylen = dctx->kdf_outlen;
228 if (*keylen != dctx->kdf_outlen)
230 if (!pkey_ec_derive(ctx, NULL, &ktmplen))
232 if ((ktmp = OPENSSL_malloc(ktmplen)) == NULL) {
233 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
236 if (!pkey_ec_derive(ctx, ktmp, &ktmplen))
239 if (!ossl_ecdh_kdf_X9_63(key, *keylen, ktmp, ktmplen,
240 dctx->kdf_ukm, dctx->kdf_ukmlen, dctx->kdf_md,
241 ctx->libctx, ctx->propquery))
246 OPENSSL_clear_free(ktmp, ktmplen);
251 static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
253 EC_PKEY_CTX *dctx = ctx->data;
256 case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
257 group = EC_GROUP_new_by_curve_name(p1);
259 ERR_raise(ERR_LIB_EC, EC_R_INVALID_CURVE);
262 EC_GROUP_free(dctx->gen_group);
263 dctx->gen_group = group;
266 case EVP_PKEY_CTRL_EC_PARAM_ENC:
267 if (!dctx->gen_group) {
268 ERR_raise(ERR_LIB_EC, EC_R_NO_PARAMETERS_SET);
271 EC_GROUP_set_asn1_flag(dctx->gen_group, p1);
274 #ifndef OPENSSL_NO_EC
275 case EVP_PKEY_CTRL_EC_ECDH_COFACTOR:
277 if (dctx->cofactor_mode != -1)
278 return dctx->cofactor_mode;
280 const EC_KEY *ec_key = EVP_PKEY_get0_EC_KEY(ctx->pkey);
281 return EC_KEY_get_flags(ec_key) & EC_FLAG_COFACTOR_ECDH ? 1 : 0;
283 } else if (p1 < -1 || p1 > 1)
285 dctx->cofactor_mode = p1;
287 EC_KEY *ec_key = (EC_KEY *)EVP_PKEY_get0_EC_KEY(ctx->pkey);
290 * We discarded the "const" above. This will only work if the key is
291 * a "real" legacy key, and not a cached copy of a provided key
293 if (evp_pkey_is_provided(ctx->pkey)) {
294 ERR_raise(ERR_LIB_EC, ERR_R_UNSUPPORTED);
299 /* If cofactor is 1 cofactor mode does nothing */
300 if (BN_is_one(ec_key->group->cofactor))
303 dctx->co_key = EC_KEY_dup(ec_key);
308 EC_KEY_set_flags(dctx->co_key, EC_FLAG_COFACTOR_ECDH);
310 EC_KEY_clear_flags(dctx->co_key, EC_FLAG_COFACTOR_ECDH);
312 EC_KEY_free(dctx->co_key);
318 case EVP_PKEY_CTRL_EC_KDF_TYPE:
320 return dctx->kdf_type;
321 if (p1 != EVP_PKEY_ECDH_KDF_NONE && p1 != EVP_PKEY_ECDH_KDF_X9_63)
326 case EVP_PKEY_CTRL_EC_KDF_MD:
330 case EVP_PKEY_CTRL_GET_EC_KDF_MD:
331 *(const EVP_MD **)p2 = dctx->kdf_md;
334 case EVP_PKEY_CTRL_EC_KDF_OUTLEN:
337 dctx->kdf_outlen = (size_t)p1;
340 case EVP_PKEY_CTRL_GET_EC_KDF_OUTLEN:
341 *(int *)p2 = dctx->kdf_outlen;
344 case EVP_PKEY_CTRL_EC_KDF_UKM:
345 OPENSSL_free(dctx->kdf_ukm);
348 dctx->kdf_ukmlen = p1;
350 dctx->kdf_ukmlen = 0;
353 case EVP_PKEY_CTRL_GET_EC_KDF_UKM:
354 *(unsigned char **)p2 = dctx->kdf_ukm;
355 return dctx->kdf_ukmlen;
357 case EVP_PKEY_CTRL_MD:
358 if (EVP_MD_get_type((const EVP_MD *)p2) != NID_sha1 &&
359 EVP_MD_get_type((const EVP_MD *)p2) != NID_ecdsa_with_SHA1 &&
360 EVP_MD_get_type((const EVP_MD *)p2) != NID_sha224 &&
361 EVP_MD_get_type((const EVP_MD *)p2) != NID_sha256 &&
362 EVP_MD_get_type((const EVP_MD *)p2) != NID_sha384 &&
363 EVP_MD_get_type((const EVP_MD *)p2) != NID_sha512 &&
364 EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_224 &&
365 EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_256 &&
366 EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_384 &&
367 EVP_MD_get_type((const EVP_MD *)p2) != NID_sha3_512 &&
368 EVP_MD_get_type((const EVP_MD *)p2) != NID_sm3) {
369 ERR_raise(ERR_LIB_EC, EC_R_INVALID_DIGEST_TYPE);
375 case EVP_PKEY_CTRL_GET_MD:
376 *(const EVP_MD **)p2 = dctx->md;
379 case EVP_PKEY_CTRL_PEER_KEY:
380 /* Default behaviour is OK */
381 case EVP_PKEY_CTRL_DIGESTINIT:
382 case EVP_PKEY_CTRL_PKCS7_SIGN:
383 case EVP_PKEY_CTRL_CMS_SIGN:
392 static int pkey_ec_ctrl_str(EVP_PKEY_CTX *ctx,
393 const char *type, const char *value)
395 if (strcmp(type, "ec_paramgen_curve") == 0) {
397 nid = EC_curve_nist2nid(value);
398 if (nid == NID_undef)
399 nid = OBJ_sn2nid(value);
400 if (nid == NID_undef)
401 nid = OBJ_ln2nid(value);
402 if (nid == NID_undef) {
403 ERR_raise(ERR_LIB_EC, EC_R_INVALID_CURVE);
406 return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid);
407 } else if (strcmp(type, "ec_param_enc") == 0) {
409 if (strcmp(value, "explicit") == 0)
411 else if (strcmp(value, "named_curve") == 0)
412 param_enc = OPENSSL_EC_NAMED_CURVE;
415 return EVP_PKEY_CTX_set_ec_param_enc(ctx, param_enc);
416 } else if (strcmp(type, "ecdh_kdf_md") == 0) {
418 if ((md = EVP_get_digestbyname(value)) == NULL) {
419 ERR_raise(ERR_LIB_EC, EC_R_INVALID_DIGEST);
422 return EVP_PKEY_CTX_set_ecdh_kdf_md(ctx, md);
423 } else if (strcmp(type, "ecdh_cofactor_mode") == 0) {
425 co_mode = atoi(value);
426 return EVP_PKEY_CTX_set_ecdh_cofactor_mode(ctx, co_mode);
432 static int pkey_ec_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
435 EC_PKEY_CTX *dctx = ctx->data;
438 if (dctx->gen_group == NULL) {
439 ERR_raise(ERR_LIB_EC, EC_R_NO_PARAMETERS_SET);
445 if (!(ret = EC_KEY_set_group(ec, dctx->gen_group))
446 || !ossl_assert(ret = EVP_PKEY_assign_EC_KEY(pkey, ec)))
451 static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
454 EC_PKEY_CTX *dctx = ctx->data;
457 if (ctx->pkey == NULL && dctx->gen_group == NULL) {
458 ERR_raise(ERR_LIB_EC, EC_R_NO_PARAMETERS_SET);
464 if (!ossl_assert(EVP_PKEY_assign_EC_KEY(pkey, ec))) {
468 /* Note: if error is returned, we count on caller to free pkey->pkey.ec */
469 if (ctx->pkey != NULL)
470 ret = EVP_PKEY_copy_parameters(pkey, ctx->pkey);
472 ret = EC_KEY_set_group(ec, dctx->gen_group);
474 return ret ? EC_KEY_generate_key(ec) : 0;
477 static const EVP_PKEY_METHOD ec_pkey_meth = {
507 #ifndef OPENSSL_NO_EC
516 const EVP_PKEY_METHOD *ossl_ec_pkey_method(void)
518 return &ec_pkey_meth;