2 * Copyright 2006-2020 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 ECerr(EC_F_PKEY_EC_INIT, 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;
112 EC_KEY *ec = ctx->pkey->pkey.ec;
113 const int sig_sz = ECDSA_size(ec);
115 /* ensure cast to size_t is safe */
116 if (!ossl_assert(sig_sz > 0))
120 *siglen = (size_t)sig_sz;
124 if (*siglen < (size_t)sig_sz) {
125 ECerr(EC_F_PKEY_EC_SIGN, EC_R_BUFFER_TOO_SMALL);
129 type = (dctx->md != NULL) ? EVP_MD_type(dctx->md) : NID_sha1;
131 ret = ECDSA_sign(type, tbs, tbslen, sig, &sltmp, ec);
135 *siglen = (size_t)sltmp;
139 static int pkey_ec_verify(EVP_PKEY_CTX *ctx,
140 const unsigned char *sig, size_t siglen,
141 const unsigned char *tbs, size_t tbslen)
144 EC_PKEY_CTX *dctx = ctx->data;
145 EC_KEY *ec = ctx->pkey->pkey.ec;
148 type = EVP_MD_type(dctx->md);
152 ret = ECDSA_verify(type, tbs, tbslen, sig, siglen, ec);
157 #ifndef OPENSSL_NO_EC
158 static int pkey_ec_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
162 const EC_POINT *pubkey = NULL;
164 EC_PKEY_CTX *dctx = ctx->data;
165 if (!ctx->pkey || !ctx->peerkey) {
166 ECerr(EC_F_PKEY_EC_DERIVE, EC_R_KEYS_NOT_SET);
170 eckey = dctx->co_key ? dctx->co_key : ctx->pkey->pkey.ec;
173 const EC_GROUP *group;
174 group = EC_KEY_get0_group(eckey);
175 *keylen = (EC_GROUP_get_degree(group) + 7) / 8;
178 pubkey = EC_KEY_get0_public_key(ctx->peerkey->pkey.ec);
181 * NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is not
182 * an error, the result is truncated.
187 ret = ECDH_compute_key(key, outlen, pubkey, eckey, 0);
194 static int pkey_ec_kdf_derive(EVP_PKEY_CTX *ctx,
195 unsigned char *key, size_t *keylen)
197 EC_PKEY_CTX *dctx = ctx->data;
198 unsigned char *ktmp = NULL;
201 if (dctx->kdf_type == EVP_PKEY_ECDH_KDF_NONE)
202 return pkey_ec_derive(ctx, key, keylen);
204 *keylen = dctx->kdf_outlen;
207 if (*keylen != dctx->kdf_outlen)
209 if (!pkey_ec_derive(ctx, NULL, &ktmplen))
211 if ((ktmp = OPENSSL_malloc(ktmplen)) == NULL) {
212 ECerr(EC_F_PKEY_EC_KDF_DERIVE, ERR_R_MALLOC_FAILURE);
215 if (!pkey_ec_derive(ctx, ktmp, &ktmplen))
218 if (!ecdh_KDF_X9_63(key, *keylen, ktmp, ktmplen,
219 dctx->kdf_ukm, dctx->kdf_ukmlen, dctx->kdf_md))
224 OPENSSL_clear_free(ktmp, ktmplen);
229 static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
231 EC_PKEY_CTX *dctx = ctx->data;
234 case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
235 group = EC_GROUP_new_by_curve_name(p1);
237 ECerr(EC_F_PKEY_EC_CTRL, EC_R_INVALID_CURVE);
240 EC_GROUP_free(dctx->gen_group);
241 dctx->gen_group = group;
244 case EVP_PKEY_CTRL_EC_PARAM_ENC:
245 if (!dctx->gen_group) {
246 ECerr(EC_F_PKEY_EC_CTRL, EC_R_NO_PARAMETERS_SET);
249 EC_GROUP_set_asn1_flag(dctx->gen_group, p1);
252 #ifndef OPENSSL_NO_EC
253 case EVP_PKEY_CTRL_EC_ECDH_COFACTOR:
255 if (dctx->cofactor_mode != -1)
256 return dctx->cofactor_mode;
258 EC_KEY *ec_key = ctx->pkey->pkey.ec;
259 return EC_KEY_get_flags(ec_key) & EC_FLAG_COFACTOR_ECDH ? 1 : 0;
261 } else if (p1 < -1 || p1 > 1)
263 dctx->cofactor_mode = p1;
265 EC_KEY *ec_key = ctx->pkey->pkey.ec;
268 /* If cofactor is 1 cofactor mode does nothing */
269 if (BN_is_one(ec_key->group->cofactor))
272 dctx->co_key = EC_KEY_dup(ec_key);
277 EC_KEY_set_flags(dctx->co_key, EC_FLAG_COFACTOR_ECDH);
279 EC_KEY_clear_flags(dctx->co_key, EC_FLAG_COFACTOR_ECDH);
281 EC_KEY_free(dctx->co_key);
287 case EVP_PKEY_CTRL_EC_KDF_TYPE:
289 return dctx->kdf_type;
290 if (p1 != EVP_PKEY_ECDH_KDF_NONE && p1 != EVP_PKEY_ECDH_KDF_X9_63)
295 case EVP_PKEY_CTRL_EC_KDF_MD:
299 case EVP_PKEY_CTRL_GET_EC_KDF_MD:
300 *(const EVP_MD **)p2 = dctx->kdf_md;
303 case EVP_PKEY_CTRL_EC_KDF_OUTLEN:
306 dctx->kdf_outlen = (size_t)p1;
309 case EVP_PKEY_CTRL_GET_EC_KDF_OUTLEN:
310 *(int *)p2 = dctx->kdf_outlen;
313 case EVP_PKEY_CTRL_EC_KDF_UKM:
314 OPENSSL_free(dctx->kdf_ukm);
317 dctx->kdf_ukmlen = p1;
319 dctx->kdf_ukmlen = 0;
322 case EVP_PKEY_CTRL_GET_EC_KDF_UKM:
323 *(unsigned char **)p2 = dctx->kdf_ukm;
324 return dctx->kdf_ukmlen;
326 case EVP_PKEY_CTRL_MD:
327 if (EVP_MD_type((const EVP_MD *)p2) != NID_sha1 &&
328 EVP_MD_type((const EVP_MD *)p2) != NID_ecdsa_with_SHA1 &&
329 EVP_MD_type((const EVP_MD *)p2) != NID_sha224 &&
330 EVP_MD_type((const EVP_MD *)p2) != NID_sha256 &&
331 EVP_MD_type((const EVP_MD *)p2) != NID_sha384 &&
332 EVP_MD_type((const EVP_MD *)p2) != NID_sha512 &&
333 EVP_MD_type((const EVP_MD *)p2) != NID_sha3_224 &&
334 EVP_MD_type((const EVP_MD *)p2) != NID_sha3_256 &&
335 EVP_MD_type((const EVP_MD *)p2) != NID_sha3_384 &&
336 EVP_MD_type((const EVP_MD *)p2) != NID_sha3_512 &&
337 EVP_MD_type((const EVP_MD *)p2) != NID_sm3) {
338 ECerr(EC_F_PKEY_EC_CTRL, EC_R_INVALID_DIGEST_TYPE);
344 case EVP_PKEY_CTRL_GET_MD:
345 *(const EVP_MD **)p2 = dctx->md;
348 case EVP_PKEY_CTRL_PEER_KEY:
349 /* Default behaviour is OK */
350 case EVP_PKEY_CTRL_DIGESTINIT:
351 case EVP_PKEY_CTRL_PKCS7_SIGN:
352 case EVP_PKEY_CTRL_CMS_SIGN:
361 static int pkey_ec_ctrl_str(EVP_PKEY_CTX *ctx,
362 const char *type, const char *value)
364 if (strcmp(type, "ec_paramgen_curve") == 0) {
366 nid = EC_curve_nist2nid(value);
367 if (nid == NID_undef)
368 nid = OBJ_sn2nid(value);
369 if (nid == NID_undef)
370 nid = OBJ_ln2nid(value);
371 if (nid == NID_undef) {
372 ECerr(EC_F_PKEY_EC_CTRL_STR, EC_R_INVALID_CURVE);
375 return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid);
376 } else if (strcmp(type, "ec_param_enc") == 0) {
378 if (strcmp(value, "explicit") == 0)
380 else if (strcmp(value, "named_curve") == 0)
381 param_enc = OPENSSL_EC_NAMED_CURVE;
384 return EVP_PKEY_CTX_set_ec_param_enc(ctx, param_enc);
385 } else if (strcmp(type, "ecdh_kdf_md") == 0) {
387 if ((md = EVP_get_digestbyname(value)) == NULL) {
388 ECerr(EC_F_PKEY_EC_CTRL_STR, EC_R_INVALID_DIGEST);
391 return EVP_PKEY_CTX_set_ecdh_kdf_md(ctx, md);
392 } else if (strcmp(type, "ecdh_cofactor_mode") == 0) {
394 co_mode = atoi(value);
395 return EVP_PKEY_CTX_set_ecdh_cofactor_mode(ctx, co_mode);
401 static int pkey_ec_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
404 EC_PKEY_CTX *dctx = ctx->data;
407 if (dctx->gen_group == NULL) {
408 ECerr(EC_F_PKEY_EC_PARAMGEN, EC_R_NO_PARAMETERS_SET);
414 if (!(ret = EC_KEY_set_group(ec, dctx->gen_group))
415 || !ossl_assert(ret = EVP_PKEY_assign_EC_KEY(pkey, ec)))
420 static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
423 EC_PKEY_CTX *dctx = ctx->data;
426 if (ctx->pkey == NULL && dctx->gen_group == NULL) {
427 ECerr(EC_F_PKEY_EC_KEYGEN, EC_R_NO_PARAMETERS_SET);
433 if (!ossl_assert(EVP_PKEY_assign_EC_KEY(pkey, ec))) {
437 /* Note: if error is returned, we count on caller to free pkey->pkey.ec */
438 if (ctx->pkey != NULL)
439 ret = EVP_PKEY_copy_parameters(pkey, ctx->pkey);
441 ret = EC_KEY_set_group(ec, dctx->gen_group);
443 return ret ? EC_KEY_generate_key(ec) : 0;
446 static const EVP_PKEY_METHOD ec_pkey_meth = {
476 #ifndef OPENSSL_NO_EC
485 const EVP_PKEY_METHOD *ec_pkey_method(void)
487 return &ec_pkey_meth;