| 484 | } |
| 485 | |
| 486 | bool ECIESDecrypt (const EC_GROUP * curve, const BIGNUM * key, const uint8_t * encrypted, uint8_t * data) |
| 487 | { |
| 488 | bool ret = true; |
| 489 | BN_CTX * ctx = BN_CTX_new (); |
| 490 | BN_CTX_start (ctx); |
| 491 | BIGNUM * q = BN_CTX_get (ctx); |
| 492 | EC_GROUP_get_order(curve, q, ctx); |
| 493 | int len = BN_num_bytes (q); |
| 494 | // point for shared secret |
| 495 | BIGNUM * x = BN_CTX_get (ctx), * y = BN_CTX_get (ctx); |
| 496 | BN_bin2bn (encrypted + 1, len, x); |
| 497 | BN_bin2bn (encrypted + 1 + len, len, y); |
| 498 | auto p = EC_POINT_new (curve); |
| 499 | if (EC_POINT_set_affine_coordinates (curve, p, x, y, nullptr)) |
| 500 | { |
| 501 | auto s = EC_POINT_new (curve); |
| 502 | EC_POINT_mul (curve, s, nullptr, p, key, ctx); |
| 503 | EC_POINT_get_affine_coordinates (curve, s, x, y, nullptr); |
| 504 | EC_POINT_free (s); |
| 505 | uint8_t keyBuf[64], iv[64], shared[32]; |
| 506 | bn2buf (x, keyBuf, len); |
| 507 | bn2buf (y, iv, len); |
| 508 | SHA256 (keyBuf, len, shared); |
| 509 | // decrypt |
| 510 | uint8_t m[256]; |
| 511 | CBCDecryption decryption; |
| 512 | decryption.SetKey (shared); |
| 513 | decryption.Decrypt (encrypted + 258, 256, iv, m); |
| 514 | // verify and copy |
| 515 | uint8_t hash[32]; |
| 516 | SHA256 (m + 33, 222, hash); |
| 517 | if (!memcmp (m + 1, hash, 32)) |
| 518 | memcpy (data, m + 33, 222); |
| 519 | else |
| 520 | { |
| 521 | LogPrint (eLogError, "ECIES decrypt hash doesn't match"); |
| 522 | ret = false; |
| 523 | } |
| 524 | } |
| 525 | else |
| 526 | { |
| 527 | LogPrint (eLogError, "ECIES decrypt point is invalid"); |
| 528 | ret = false; |
| 529 | } |
| 530 | |
| 531 | EC_POINT_free (p); |
| 532 | BN_CTX_end (ctx); |
| 533 | BN_CTX_free (ctx); |
| 534 | return ret; |
| 535 | } |
| 536 | |
| 537 | void GenerateECIESKeyPair (const EC_GROUP * curve, BIGNUM *& priv, EC_POINT *& pub) |
| 538 | { |