crypto/ec/ecx_meth.c

   1 /*
   2  * Copyright 2006-2018 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 <openssl/x509.h>
  13 #include <openssl/ec.h>
  14 #include <openssl/rand.h>
  15 #include "internal/asn1_int.h"
  16 #include "internal/evp_int.h"
  17 #include "ec_lcl.h"
  18 #include "curve448/curve448_lcl.h"
  19
  20 #define X25519_BITS          253
  21 #define X25519_SECURITY_BITS 128
  22
  23 #define ED25519_SIGSIZE      64
  24
  25 #define X448_BITS            448
  26 #define ED448_BITS           456
  27 #define X448_SECURITY_BITS   224
  28
  29 #define ED448_SIGSIZE        114
  30
  31 #define ISX448(id)      ((id) == EVP_PKEY_X448)
  32 #define IS25519(id)     ((id) == EVP_PKEY_X25519 || (id) == EVP_PKEY_ED25519)
  33 #define KEYLENID(id)    (IS25519(id) ? X25519_KEYLEN \
  34                                      : ((id) == EVP_PKEY_X448 ? X448_KEYLEN \
  35                                                               : ED448_KEYLEN))
  36 #define KEYLEN(p)       KEYLENID((p)->ameth->pkey_id)
  37
  38
  39 typedef enum {
  40     KEY_OP_PUBLIC,
  41     KEY_OP_PRIVATE,
  42     KEY_OP_KEYGEN
  43 } ecx_key_op_t;
  44
  45 /* Setup EVP_PKEY using public, private or generation */
  46 static int ecx_key_op(EVP_PKEY *pkey, int id, const X509_ALGOR *palg,
  47                       const unsigned char *p, int plen, ecx_key_op_t op)
  48 {
  49     ECX_KEY *key = NULL;
  50     unsigned char *privkey, *pubkey;
  51
  52     if (op != KEY_OP_KEYGEN) {
  53         if (palg != NULL) {
  54             int ptype;
  55
  56             /* Algorithm parameters must be absent */
  57             X509_ALGOR_get0(NULL, &ptype, NULL, palg);
  58             if (ptype != V_ASN1_UNDEF) {
  59                 ECerr(EC_F_ECX_KEY_OP, EC_R_INVALID_ENCODING);
  60                 return 0;
  61             }
  62         }
  63
  64         if (p == NULL || plen != KEYLENID(id)) {
  65             ECerr(EC_F_ECX_KEY_OP, EC_R_INVALID_ENCODING);
  66             return 0;
  67         }
  68     }
  69
  70     key = OPENSSL_zalloc(sizeof(*key));
  71     if (key == NULL) {
  72         ECerr(EC_F_ECX_KEY_OP, ERR_R_MALLOC_FAILURE);
  73         return 0;
  74     }
  75     pubkey = key->pubkey;
  76
  77     if (op == KEY_OP_PUBLIC) {
  78         memcpy(pubkey, p, plen);
  79     } else {
  80         privkey = key->privkey = OPENSSL_secure_malloc(KEYLENID(id));
  81         if (privkey == NULL) {
  82             ECerr(EC_F_ECX_KEY_OP, ERR_R_MALLOC_FAILURE);
  83             goto err;
  84         }
  85         if (op == KEY_OP_KEYGEN) {
  86             if (RAND_priv_bytes(privkey, KEYLENID(id)) <= 0) {
  87                 OPENSSL_secure_free(privkey);
  88                 key->privkey = NULL;
  89                 goto err;
  90             }
  91             if (id == EVP_PKEY_X25519) {
  92                 privkey[0] &= 248;
  93                 privkey[X25519_KEYLEN - 1] &= 127;
  94                 privkey[X25519_KEYLEN - 1] |= 64;
  95             } else if (id == EVP_PKEY_X448) {
  96                 privkey[0] &= 252;
  97                 privkey[X448_KEYLEN - 1] |= 128;
  98             }
  99         } else {
 100             memcpy(privkey, p, KEYLENID(id));
 101         }
 102         switch (id) {
 103         case EVP_PKEY_X25519:
 104             X25519_public_from_private(pubkey, privkey);
 105             break;
 106         case EVP_PKEY_ED25519:
 107             ED25519_public_from_private(pubkey, privkey);
 108             break;
 109         case EVP_PKEY_X448:
 110             X448_public_from_private(pubkey, privkey);
 111             break;
 112         case EVP_PKEY_ED448:
 113             /*
 114              * TODO(3.0): We set the library context to NULL for now. This will
 115              * need to change.
 116              */
 117             ED448_public_from_private(NULL, pubkey, privkey);
 118             break;
 119         }
 120     }
 121
 122     EVP_PKEY_assign(pkey, id, key);
 123     return 1;
 124  err:
 125     OPENSSL_free(key);
 126     return 0;
 127 }
 128
 129 static int ecx_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
 130 {
 131     const ECX_KEY *ecxkey = pkey->pkey.ecx;
 132     unsigned char *penc;
 133
 134     if (ecxkey == NULL) {
 135         ECerr(EC_F_ECX_PUB_ENCODE, EC_R_INVALID_KEY);
 136         return 0;
 137     }
 138
 139     penc = OPENSSL_memdup(ecxkey->pubkey, KEYLEN(pkey));
 140     if (penc == NULL) {
 141         ECerr(EC_F_ECX_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 142         return 0;
 143     }
 144
 145     if (!X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
 146                                 V_ASN1_UNDEF, NULL, penc, KEYLEN(pkey))) {
 147         OPENSSL_free(penc);
 148         ECerr(EC_F_ECX_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
 149         return 0;
 150     }
 151     return 1;
 152 }
 153
 154 static int ecx_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
 155 {
 156     const unsigned char *p;
 157     int pklen;
 158     X509_ALGOR *palg;
 159
 160     if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
 161         return 0;
 162     return ecx_key_op(pkey, pkey->ameth->pkey_id, palg, p, pklen,
 163                       KEY_OP_PUBLIC);
 164 }
 165
 166 static int ecx_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 167 {
 168     const ECX_KEY *akey = a->pkey.ecx;
 169     const ECX_KEY *bkey = b->pkey.ecx;
 170
 171     if (akey == NULL || bkey == NULL)
 172         return -2;
 173
 174     return CRYPTO_memcmp(akey->pubkey, bkey->pubkey, KEYLEN(a)) == 0;
 175 }
 176
 177 static int ecx_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
 178 {
 179     const unsigned char *p;
 180     int plen;
 181     ASN1_OCTET_STRING *oct = NULL;
 182     const X509_ALGOR *palg;
 183     int rv;
 184
 185     if (!PKCS8_pkey_get0(NULL, &p, &plen, &palg, p8))
 186         return 0;
 187
 188     oct = d2i_ASN1_OCTET_STRING(NULL, &p, plen);
 189     if (oct == NULL) {
 190         p = NULL;
 191         plen = 0;
 192     } else {
 193         p = ASN1_STRING_get0_data(oct);
 194         plen = ASN1_STRING_length(oct);
 195     }
 196
 197     rv = ecx_key_op(pkey, pkey->ameth->pkey_id, palg, p, plen, KEY_OP_PRIVATE);
 198     ASN1_OCTET_STRING_free(oct);
 199     return rv;
 200 }
 201
 202 static int ecx_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 203 {
 204     const ECX_KEY *ecxkey = pkey->pkey.ecx;
 205     ASN1_OCTET_STRING oct;
 206     unsigned char *penc = NULL;
 207     int penclen;
 208
 209     if (ecxkey == NULL || ecxkey->privkey == NULL) {
 210         ECerr(EC_F_ECX_PRIV_ENCODE, EC_R_INVALID_PRIVATE_KEY);
 211         return 0;
 212     }
 213
 214     oct.data = ecxkey->privkey;
 215     oct.length = KEYLEN(pkey);
 216     oct.flags = 0;
 217
 218     penclen = i2d_ASN1_OCTET_STRING(&oct, &penc);
 219     if (penclen < 0) {
 220         ECerr(EC_F_ECX_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 221         return 0;
 222     }
 223
 224     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
 225                          V_ASN1_UNDEF, NULL, penc, penclen)) {
 226         OPENSSL_clear_free(penc, penclen);
 227         ECerr(EC_F_ECX_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
 228         return 0;
 229     }
 230
 231     return 1;
 232 }
 233
 234 static int ecx_size(const EVP_PKEY *pkey)
 235 {
 236     return KEYLEN(pkey);
 237 }
 238
 239 static int ecx_bits(const EVP_PKEY *pkey)
 240 {
 241     if (IS25519(pkey->ameth->pkey_id)) {
 242         return X25519_BITS;
 243     } else if(ISX448(pkey->ameth->pkey_id)) {
 244         return X448_BITS;
 245     } else {
 246         return ED448_BITS;
 247     }
 248 }
 249
 250 static int ecx_security_bits(const EVP_PKEY *pkey)
 251 {
 252     if (IS25519(pkey->ameth->pkey_id)) {
 253         return X25519_SECURITY_BITS;
 254     } else {
 255         return X448_SECURITY_BITS;
 256     }
 257 }
 258
 259 static void ecx_free(EVP_PKEY *pkey)
 260 {
 261     if (pkey->pkey.ecx != NULL)
 262         OPENSSL_secure_clear_free(pkey->pkey.ecx->privkey, KEYLEN(pkey));
 263     OPENSSL_free(pkey->pkey.ecx);
 264 }
 265
 266 /* "parameters" are always equal */
 267 static int ecx_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 268 {
 269     return 1;
 270 }
 271
 272 static int ecx_key_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 273                          ASN1_PCTX *ctx, ecx_key_op_t op)
 274 {
 275     const ECX_KEY *ecxkey = pkey->pkey.ecx;
 276     const char *nm = OBJ_nid2ln(pkey->ameth->pkey_id);
 277
 278     if (op == KEY_OP_PRIVATE) {
 279         if (ecxkey == NULL || ecxkey->privkey == NULL) {
 280             if (BIO_printf(bp, "%*s<INVALID PRIVATE KEY>\n", indent, "") <= 0)
 281                 return 0;
 282             return 1;
 283         }
 284         if (BIO_printf(bp, "%*s%s Private-Key:\n", indent, "", nm) <= 0)
 285             return 0;
 286         if (BIO_printf(bp, "%*spriv:\n", indent, "") <= 0)
 287             return 0;
 288         if (ASN1_buf_print(bp, ecxkey->privkey, KEYLEN(pkey),
 289                            indent + 4) == 0)
 290             return 0;
 291     } else {
 292         if (ecxkey == NULL) {
 293             if (BIO_printf(bp, "%*s<INVALID PUBLIC KEY>\n", indent, "") <= 0)
 294                 return 0;
 295             return 1;
 296         }
 297         if (BIO_printf(bp, "%*s%s Public-Key:\n", indent, "", nm) <= 0)
 298             return 0;
 299     }
 300     if (BIO_printf(bp, "%*spub:\n", indent, "") <= 0)
 301         return 0;
 302
 303     if (ASN1_buf_print(bp, ecxkey->pubkey, KEYLEN(pkey),
 304                        indent + 4) == 0)
 305         return 0;
 306     return 1;
 307 }
 308
 309 static int ecx_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 310                           ASN1_PCTX *ctx)
 311 {
 312     return ecx_key_print(bp, pkey, indent, ctx, KEY_OP_PRIVATE);
 313 }
 314
 315 static int ecx_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
 316                          ASN1_PCTX *ctx)
 317 {
 318     return ecx_key_print(bp, pkey, indent, ctx, KEY_OP_PUBLIC);
 319 }
 320
 321 static int ecx_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 322 {
 323     switch (op) {
 324
 325     case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
 326         return ecx_key_op(pkey, pkey->ameth->pkey_id, NULL, arg2, arg1,
 327                           KEY_OP_PUBLIC);
 328
 329     case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
 330         if (pkey->pkey.ecx != NULL) {
 331             unsigned char **ppt = arg2;
 332
 333             *ppt = OPENSSL_memdup(pkey->pkey.ecx->pubkey, KEYLEN(pkey));
 334             if (*ppt != NULL)
 335                 return KEYLEN(pkey);
 336         }
 337         return 0;
 338
 339     default:
 340         return -2;
 341
 342     }
 343 }
 344
 345 static int ecd_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
 346 {
 347     switch (op) {
 348     case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
 349         /* We currently only support Pure EdDSA which takes no digest */
 350         *(int *)arg2 = NID_undef;
 351         return 2;
 352
 353     default:
 354         return -2;
 355
 356     }
 357 }
 358
 359 static int ecx_set_priv_key(EVP_PKEY *pkey, const unsigned char *priv,
 360                             size_t len)
 361 {
 362     return ecx_key_op(pkey, pkey->ameth->pkey_id, NULL, priv, len,
 363                        KEY_OP_PRIVATE);
 364 }
 365
 366 static int ecx_set_pub_key(EVP_PKEY *pkey, const unsigned char *pub, size_t len)
 367 {
 368     return ecx_key_op(pkey, pkey->ameth->pkey_id, NULL, pub, len,
 369                       KEY_OP_PUBLIC);
 370 }
 371
 372 static int ecx_get_priv_key(const EVP_PKEY *pkey, unsigned char *priv,
 373                             size_t *len)
 374 {
 375     const ECX_KEY *key = pkey->pkey.ecx;
 376
 377     if (priv == NULL) {
 378         *len = KEYLENID(pkey->ameth->pkey_id);
 379         return 1;
 380     }
 381
 382     if (key == NULL
 383             || key->privkey == NULL
 384             || *len < (size_t)KEYLENID(pkey->ameth->pkey_id))
 385         return 0;
 386
 387     *len = KEYLENID(pkey->ameth->pkey_id);
 388     memcpy(priv, key->privkey, *len);
 389
 390     return 1;
 391 }
 392
 393 static int ecx_get_pub_key(const EVP_PKEY *pkey, unsigned char *pub,
 394                            size_t *len)
 395 {
 396     const ECX_KEY *key = pkey->pkey.ecx;
 397
 398     if (pub == NULL) {
 399         *len = KEYLENID(pkey->ameth->pkey_id);
 400         return 1;
 401     }
 402
 403     if (key == NULL
 404             || *len < (size_t)KEYLENID(pkey->ameth->pkey_id))
 405         return 0;
 406
 407     *len = KEYLENID(pkey->ameth->pkey_id);
 408     memcpy(pub, key->pubkey, *len);
 409
 410     return 1;
 411 }
 412
 413 const EVP_PKEY_ASN1_METHOD ecx25519_asn1_meth = {
 414     EVP_PKEY_X25519,
 415     EVP_PKEY_X25519,
 416     0,
 417     "X25519",
 418     "OpenSSL X25519 algorithm",
 419
 420     ecx_pub_decode,
 421     ecx_pub_encode,
 422     ecx_pub_cmp,
 423     ecx_pub_print,
 424
 425     ecx_priv_decode,
 426     ecx_priv_encode,
 427     ecx_priv_print,
 428
 429     ecx_size,
 430     ecx_bits,
 431     ecx_security_bits,
 432
 433     0, 0, 0, 0,
 434     ecx_cmp_parameters,
 435     0, 0,
 436
 437     ecx_free,
 438     ecx_ctrl,
 439     NULL,
 440     NULL,
 441
 442     NULL,
 443     NULL,
 444     NULL,
 445
 446     NULL,
 447     NULL,
 448     NULL,
 449
 450     ecx_set_priv_key,
 451     ecx_set_pub_key,
 452     ecx_get_priv_key,
 453     ecx_get_pub_key,
 454 };
 455
 456 const EVP_PKEY_ASN1_METHOD ecx448_asn1_meth = {
 457     EVP_PKEY_X448,
 458     EVP_PKEY_X448,
 459     0,
 460     "X448",
 461     "OpenSSL X448 algorithm",
 462
 463     ecx_pub_decode,
 464     ecx_pub_encode,
 465     ecx_pub_cmp,
 466     ecx_pub_print,
 467
 468     ecx_priv_decode,
 469     ecx_priv_encode,
 470     ecx_priv_print,
 471
 472     ecx_size,
 473     ecx_bits,
 474     ecx_security_bits,
 475
 476     0, 0, 0, 0,
 477     ecx_cmp_parameters,
 478     0, 0,
 479
 480     ecx_free,
 481     ecx_ctrl,
 482     NULL,
 483     NULL,
 484
 485     NULL,
 486     NULL,
 487     NULL,
 488
 489     NULL,
 490     NULL,
 491     NULL,
 492
 493     ecx_set_priv_key,
 494     ecx_set_pub_key,
 495     ecx_get_priv_key,
 496     ecx_get_pub_key,
 497 };
 498
 499 static int ecd_size25519(const EVP_PKEY *pkey)
 500 {
 501     return ED25519_SIGSIZE;
 502 }
 503
 504 static int ecd_size448(const EVP_PKEY *pkey)
 505 {
 506     return ED448_SIGSIZE;
 507 }
 508
 509 static int ecd_item_verify(EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
 510                            X509_ALGOR *sigalg, ASN1_BIT_STRING *str,
 511                            EVP_PKEY *pkey)
 512 {
 513     const ASN1_OBJECT *obj;
 514     int ptype;
 515     int nid;
 516
 517     /* Sanity check: make sure it is ED25519/ED448 with absent parameters */
 518     X509_ALGOR_get0(&obj, &ptype, NULL, sigalg);
 519     nid = OBJ_obj2nid(obj);
 520     if ((nid != NID_ED25519 && nid != NID_ED448) || ptype != V_ASN1_UNDEF) {
 521         ECerr(EC_F_ECD_ITEM_VERIFY, EC_R_INVALID_ENCODING);
 522         return 0;
 523     }
 524
 525     if (!EVP_DigestVerifyInit(ctx, NULL, NULL, NULL, pkey))
 526         return 0;
 527
 528     return 2;
 529 }
 530
 531 static int ecd_item_sign25519(EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
 532                               X509_ALGOR *alg1, X509_ALGOR *alg2,
 533                               ASN1_BIT_STRING *str)
 534 {
 535     /* Set algorithms identifiers */
 536     X509_ALGOR_set0(alg1, OBJ_nid2obj(NID_ED25519), V_ASN1_UNDEF, NULL);
 537     if (alg2)
 538         X509_ALGOR_set0(alg2, OBJ_nid2obj(NID_ED25519), V_ASN1_UNDEF, NULL);
 539     /* Algorithm identifiers set: carry on as normal */
 540     return 3;
 541 }
 542
 543 static int ecd_sig_info_set25519(X509_SIG_INFO *siginf, const X509_ALGOR *alg,
 544                                  const ASN1_STRING *sig)
 545 {
 546     X509_SIG_INFO_set(siginf, NID_undef, NID_ED25519, X25519_SECURITY_BITS,
 547                       X509_SIG_INFO_TLS);
 548     return 1;
 549 }
 550
 551 static int ecd_item_sign448(EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
 552                             X509_ALGOR *alg1, X509_ALGOR *alg2,
 553                             ASN1_BIT_STRING *str)
 554 {
 555     /* Set algorithm identifier */
 556     X509_ALGOR_set0(alg1, OBJ_nid2obj(NID_ED448), V_ASN1_UNDEF, NULL);
 557     if (alg2 != NULL)
 558         X509_ALGOR_set0(alg2, OBJ_nid2obj(NID_ED448), V_ASN1_UNDEF, NULL);
 559     /* Algorithm identifier set: carry on as normal */
 560     return 3;
 561 }
 562
 563 static int ecd_sig_info_set448(X509_SIG_INFO *siginf, const X509_ALGOR *alg,
 564                                const ASN1_STRING *sig)
 565 {
 566     X509_SIG_INFO_set(siginf, NID_undef, NID_ED448, X448_SECURITY_BITS,
 567                       X509_SIG_INFO_TLS);
 568     return 1;
 569 }
 570
 571
 572 const EVP_PKEY_ASN1_METHOD ed25519_asn1_meth = {
 573     EVP_PKEY_ED25519,
 574     EVP_PKEY_ED25519,
 575     0,
 576     "ED25519",
 577     "OpenSSL ED25519 algorithm",
 578
 579     ecx_pub_decode,
 580     ecx_pub_encode,
 581     ecx_pub_cmp,
 582     ecx_pub_print,
 583
 584     ecx_priv_decode,
 585     ecx_priv_encode,
 586     ecx_priv_print,
 587
 588     ecd_size25519,
 589     ecx_bits,
 590     ecx_security_bits,
 591
 592     0, 0, 0, 0,
 593     ecx_cmp_parameters,
 594     0, 0,
 595
 596     ecx_free,
 597     ecd_ctrl,
 598     NULL,
 599     NULL,
 600     ecd_item_verify,
 601     ecd_item_sign25519,
 602     ecd_sig_info_set25519,
 603
 604     NULL,
 605     NULL,
 606     NULL,
 607
 608     ecx_set_priv_key,
 609     ecx_set_pub_key,
 610     ecx_get_priv_key,
 611     ecx_get_pub_key,
 612 };
 613
 614 const EVP_PKEY_ASN1_METHOD ed448_asn1_meth = {
 615     EVP_PKEY_ED448,
 616     EVP_PKEY_ED448,
 617     0,
 618     "ED448",
 619     "OpenSSL ED448 algorithm",
 620
 621     ecx_pub_decode,
 622     ecx_pub_encode,
 623     ecx_pub_cmp,
 624     ecx_pub_print,
 625
 626     ecx_priv_decode,
 627     ecx_priv_encode,
 628     ecx_priv_print,
 629
 630     ecd_size448,
 631     ecx_bits,
 632     ecx_security_bits,
 633
 634     0, 0, 0, 0,
 635     ecx_cmp_parameters,
 636     0, 0,
 637
 638     ecx_free,
 639     ecd_ctrl,
 640     NULL,
 641     NULL,
 642     ecd_item_verify,
 643     ecd_item_sign448,
 644     ecd_sig_info_set448,
 645
 646     NULL,
 647     NULL,
 648     NULL,
 649
 650     ecx_set_priv_key,
 651     ecx_set_pub_key,
 652     ecx_get_priv_key,
 653     ecx_get_pub_key,
 654 };
 655
 656 static int pkey_ecx_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
 657 {
 658     return ecx_key_op(pkey, ctx->pmeth->pkey_id, NULL, NULL, 0, KEY_OP_KEYGEN);
 659 }
 660
 661 static int validate_ecx_derive(EVP_PKEY_CTX *ctx, unsigned char *key,
 662                                           size_t *keylen,
 663                                           const unsigned char **privkey,
 664                                           const unsigned char **pubkey)
 665 {
 666     const ECX_KEY *ecxkey, *peerkey;
 667
 668     if (ctx->pkey == NULL || ctx->peerkey == NULL) {
 669         ECerr(EC_F_VALIDATE_ECX_DERIVE, EC_R_KEYS_NOT_SET);
 670         return 0;
 671     }
 672     ecxkey = ctx->pkey->pkey.ecx;
 673     peerkey = ctx->peerkey->pkey.ecx;
 674     if (ecxkey == NULL || ecxkey->privkey == NULL) {
 675         ECerr(EC_F_VALIDATE_ECX_DERIVE, EC_R_INVALID_PRIVATE_KEY);
 676         return 0;
 677     }
 678     if (peerkey == NULL) {
 679         ECerr(EC_F_VALIDATE_ECX_DERIVE, EC_R_INVALID_PEER_KEY);
 680         return 0;
 681     }
 682     *privkey = ecxkey->privkey;
 683     *pubkey = peerkey->pubkey;
 684
 685     return 1;
 686 }
 687
 688 static int pkey_ecx_derive25519(EVP_PKEY_CTX *ctx, unsigned char *key,
 689                                 size_t *keylen)
 690 {
 691     const unsigned char *privkey, *pubkey;
 692
 693     if (!validate_ecx_derive(ctx, key, keylen, &privkey, &pubkey)
 694             || (key != NULL
 695                 && X25519(key, privkey, pubkey) == 0))
 696         return 0;
 697     *keylen = X25519_KEYLEN;
 698     return 1;
 699 }
 700
 701 static int pkey_ecx_derive448(EVP_PKEY_CTX *ctx, unsigned char *key,
 702                               size_t *keylen)
 703 {
 704     const unsigned char *privkey, *pubkey;
 705
 706     if (!validate_ecx_derive(ctx, key, keylen, &privkey, &pubkey)
 707             || (key != NULL
 708                 && X448(key, privkey, pubkey) == 0))
 709         return 0;
 710     *keylen = X448_KEYLEN;
 711     return 1;
 712 }
 713
 714 static int pkey_ecx_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 715 {
 716     /* Only need to handle peer key for derivation */
 717     if (type == EVP_PKEY_CTRL_PEER_KEY)
 718         return 1;
 719     return -2;
 720 }
 721
 722 const EVP_PKEY_METHOD ecx25519_pkey_meth = {
 723     EVP_PKEY_X25519,
 724     0, 0, 0, 0, 0, 0, 0,
 725     pkey_ecx_keygen,
 726     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 727     pkey_ecx_derive25519,
 728     pkey_ecx_ctrl,
 729     0
 730 };
 731
 732 const EVP_PKEY_METHOD ecx448_pkey_meth = {
 733     EVP_PKEY_X448,
 734     0, 0, 0, 0, 0, 0, 0,
 735     pkey_ecx_keygen,
 736     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 737     pkey_ecx_derive448,
 738     pkey_ecx_ctrl,
 739     0
 740 };
 741
 742 static int pkey_ecd_digestsign25519(EVP_MD_CTX *ctx, unsigned char *sig,
 743                                     size_t *siglen, const unsigned char *tbs,
 744                                     size_t tbslen)
 745 {
 746     const ECX_KEY *edkey = EVP_MD_CTX_pkey_ctx(ctx)->pkey->pkey.ecx;
 747
 748     if (sig == NULL) {
 749         *siglen = ED25519_SIGSIZE;
 750         return 1;
 751     }
 752     if (*siglen < ED25519_SIGSIZE) {
 753         ECerr(EC_F_PKEY_ECD_DIGESTSIGN25519, EC_R_BUFFER_TOO_SMALL);
 754         return 0;
 755     }
 756
 757     if (ED25519_sign(sig, tbs, tbslen, edkey->pubkey, edkey->privkey) == 0)
 758         return 0;
 759     *siglen = ED25519_SIGSIZE;
 760     return 1;
 761 }
 762
 763 static int pkey_ecd_digestsign448(EVP_MD_CTX *ctx, unsigned char *sig,
 764                                   size_t *siglen, const unsigned char *tbs,
 765                                   size_t tbslen)
 766 {
 767     const ECX_KEY *edkey = EVP_MD_CTX_pkey_ctx(ctx)->pkey->pkey.ecx;
 768
 769     if (sig == NULL) {
 770         *siglen = ED448_SIGSIZE;
 771         return 1;
 772     }
 773     if (*siglen < ED448_SIGSIZE) {
 774         ECerr(EC_F_PKEY_ECD_DIGESTSIGN448, EC_R_BUFFER_TOO_SMALL);
 775         return 0;
 776     }
 777
 778     /*
 779      * TODO(3.0): We use NULL for the library context for now. Will need to
 780      * change later.
 781      */
 782     if (ED448_sign(NULL, sig, tbs, tbslen, edkey->pubkey, edkey->privkey,
 783                    NULL, 0) == 0)
 784         return 0;
 785     *siglen = ED448_SIGSIZE;
 786     return 1;
 787 }
 788
 789 static int pkey_ecd_digestverify25519(EVP_MD_CTX *ctx, const unsigned char *sig,
 790                                       size_t siglen, const unsigned char *tbs,
 791                                       size_t tbslen)
 792 {
 793     const ECX_KEY *edkey = EVP_MD_CTX_pkey_ctx(ctx)->pkey->pkey.ecx;
 794
 795     if (siglen != ED25519_SIGSIZE)
 796         return 0;
 797
 798     return ED25519_verify(tbs, tbslen, sig, edkey->pubkey);
 799 }
 800
 801 static int pkey_ecd_digestverify448(EVP_MD_CTX *ctx, const unsigned char *sig,
 802                                     size_t siglen, const unsigned char *tbs,
 803                                     size_t tbslen)
 804 {
 805     const ECX_KEY *edkey = EVP_MD_CTX_pkey_ctx(ctx)->pkey->pkey.ecx;
 806
 807     if (siglen != ED448_SIGSIZE)
 808         return 0;
 809
 810     /*
 811      * TODO(3.0): We send NULL for the OPENSSL_CTX for now. This will need to
 812      * change.
 813      */
 814     return ED448_verify(NULL, tbs, tbslen, sig, edkey->pubkey, NULL, 0);
 815 }
 816
 817 static int pkey_ecd_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 818 {
 819     switch (type) {
 820     case EVP_PKEY_CTRL_MD:
 821         /* Only NULL allowed as digest */
 822         if (p2 == NULL || (const EVP_MD *)p2 == EVP_md_null())
 823             return 1;
 824         ECerr(EC_F_PKEY_ECD_CTRL, EC_R_INVALID_DIGEST_TYPE);
 825         return 0;
 826
 827     case EVP_PKEY_CTRL_DIGESTINIT:
 828         return 1;
 829     }
 830     return -2;
 831 }
 832
 833 const EVP_PKEY_METHOD ed25519_pkey_meth = {
 834     EVP_PKEY_ED25519, EVP_PKEY_FLAG_SIGCTX_CUSTOM,
 835     0, 0, 0, 0, 0, 0,
 836     pkey_ecx_keygen,
 837     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 838     pkey_ecd_ctrl,
 839     0,
 840     pkey_ecd_digestsign25519,
 841     pkey_ecd_digestverify25519
 842 };
 843
 844 const EVP_PKEY_METHOD ed448_pkey_meth = {
 845     EVP_PKEY_ED448, EVP_PKEY_FLAG_SIGCTX_CUSTOM,
 846     0, 0, 0, 0, 0, 0,
 847     pkey_ecx_keygen,
 848     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 849     pkey_ecd_ctrl,
 850     0,
 851     pkey_ecd_digestsign448,
 852     pkey_ecd_digestverify448
 853 };