diff options
Diffstat (limited to 'src/ecwrapper.cpp')
-rw-r--r-- | src/ecwrapper.cpp | 218 |
1 files changed, 0 insertions, 218 deletions
diff --git a/src/ecwrapper.cpp b/src/ecwrapper.cpp deleted file mode 100644 index f94bc954fd..0000000000 --- a/src/ecwrapper.cpp +++ /dev/null @@ -1,218 +0,0 @@ -// Copyright (c) 2009-2014 The Bitcoin Core developers -// Distributed under the MIT software license, see the accompanying -// file COPYING or http://www.opensource.org/licenses/mit-license.php. - -#include "ecwrapper.h" - -#include "serialize.h" -#include "uint256.h" - -#include <openssl/bn.h> -#include <openssl/ecdsa.h> -#include <openssl/obj_mac.h> - -namespace { - -class ecgroup_order -{ -public: - static const EC_GROUP* get() - { - static const ecgroup_order wrapper; - return wrapper.pgroup; - } - -private: - ecgroup_order() - : pgroup(EC_GROUP_new_by_curve_name(NID_secp256k1)) - { - } - - ~ecgroup_order() - { - EC_GROUP_free(pgroup); - } - - EC_GROUP* pgroup; -}; - -/** - * Perform ECDSA key recovery (see SEC1 4.1.6) for curves over (mod p)-fields - * recid selects which key is recovered - * if check is non-zero, additional checks are performed - */ -int ECDSA_SIG_recover_key_GFp(EC_KEY *eckey, ECDSA_SIG *ecsig, const unsigned char *msg, int msglen, int recid, int check) -{ - if (!eckey) return 0; - - int ret = 0; - BN_CTX *ctx = NULL; - - BIGNUM *x = NULL; - BIGNUM *e = NULL; - BIGNUM *order = NULL; - BIGNUM *sor = NULL; - BIGNUM *eor = NULL; - BIGNUM *field = NULL; - EC_POINT *R = NULL; - EC_POINT *O = NULL; - EC_POINT *Q = NULL; - BIGNUM *rr = NULL; - BIGNUM *zero = NULL; - int n = 0; - int i = recid / 2; - - const EC_GROUP *group = EC_KEY_get0_group(eckey); - if ((ctx = BN_CTX_new()) == NULL) { ret = -1; goto err; } - BN_CTX_start(ctx); - order = BN_CTX_get(ctx); - if (!EC_GROUP_get_order(group, order, ctx)) { ret = -2; goto err; } - x = BN_CTX_get(ctx); - if (!BN_copy(x, order)) { ret=-1; goto err; } - if (!BN_mul_word(x, i)) { ret=-1; goto err; } - if (!BN_add(x, x, ecsig->r)) { ret=-1; goto err; } - field = BN_CTX_get(ctx); - if (!EC_GROUP_get_curve_GFp(group, field, NULL, NULL, ctx)) { ret=-2; goto err; } - if (BN_cmp(x, field) >= 0) { ret=0; goto err; } - if ((R = EC_POINT_new(group)) == NULL) { ret = -2; goto err; } - if (!EC_POINT_set_compressed_coordinates_GFp(group, R, x, recid % 2, ctx)) { ret=0; goto err; } - if (check) - { - if ((O = EC_POINT_new(group)) == NULL) { ret = -2; goto err; } - if (!EC_POINT_mul(group, O, NULL, R, order, ctx)) { ret=-2; goto err; } - if (!EC_POINT_is_at_infinity(group, O)) { ret = 0; goto err; } - } - if ((Q = EC_POINT_new(group)) == NULL) { ret = -2; goto err; } - n = EC_GROUP_get_degree(group); - e = BN_CTX_get(ctx); - if (!BN_bin2bn(msg, msglen, e)) { ret=-1; goto err; } - if (8*msglen > n) BN_rshift(e, e, 8-(n & 7)); - zero = BN_CTX_get(ctx); - if (!BN_zero(zero)) { ret=-1; goto err; } - if (!BN_mod_sub(e, zero, e, order, ctx)) { ret=-1; goto err; } - rr = BN_CTX_get(ctx); - if (!BN_mod_inverse(rr, ecsig->r, order, ctx)) { ret=-1; goto err; } - sor = BN_CTX_get(ctx); - if (!BN_mod_mul(sor, ecsig->s, rr, order, ctx)) { ret=-1; goto err; } - eor = BN_CTX_get(ctx); - if (!BN_mod_mul(eor, e, rr, order, ctx)) { ret=-1; goto err; } - if (!EC_POINT_mul(group, Q, eor, R, sor, ctx)) { ret=-2; goto err; } - if (!EC_KEY_set_public_key(eckey, Q)) { ret=-2; goto err; } - - ret = 1; - -err: - if (ctx) { - BN_CTX_end(ctx); - BN_CTX_free(ctx); - } - if (R != NULL) EC_POINT_free(R); - if (O != NULL) EC_POINT_free(O); - if (Q != NULL) EC_POINT_free(Q); - return ret; -} - -} // anon namespace - -CECKey::CECKey() { - pkey = EC_KEY_new(); - assert(pkey != NULL); - int result = EC_KEY_set_group(pkey, ecgroup_order::get()); - assert(result); -} - -CECKey::~CECKey() { - EC_KEY_free(pkey); -} - -void CECKey::GetPubKey(std::vector<unsigned char> &pubkey, bool fCompressed) { - EC_KEY_set_conv_form(pkey, fCompressed ? POINT_CONVERSION_COMPRESSED : POINT_CONVERSION_UNCOMPRESSED); - int nSize = i2o_ECPublicKey(pkey, NULL); - assert(nSize); - assert(nSize <= 65); - pubkey.clear(); - pubkey.resize(nSize); - unsigned char *pbegin(begin_ptr(pubkey)); - int nSize2 = i2o_ECPublicKey(pkey, &pbegin); - assert(nSize == nSize2); -} - -bool CECKey::SetPubKey(const unsigned char* pubkey, size_t size) { - return o2i_ECPublicKey(&pkey, &pubkey, size) != NULL; -} - -bool CECKey::Verify(const uint256 &hash, const std::vector<unsigned char>& vchSig) { - if (vchSig.empty()) - return false; - - // New versions of OpenSSL will reject non-canonical DER signatures. de/re-serialize first. - unsigned char *norm_der = NULL; - ECDSA_SIG *norm_sig = ECDSA_SIG_new(); - const unsigned char* sigptr = &vchSig[0]; - assert(norm_sig); - if (d2i_ECDSA_SIG(&norm_sig, &sigptr, vchSig.size()) == NULL) - { - /* As of OpenSSL 1.0.0p d2i_ECDSA_SIG frees and nulls the pointer on - * error. But OpenSSL's own use of this function redundantly frees the - * result. As ECDSA_SIG_free(NULL) is a no-op, and in the absence of a - * clear contract for the function behaving the same way is more - * conservative. - */ - ECDSA_SIG_free(norm_sig); - return false; - } - int derlen = i2d_ECDSA_SIG(norm_sig, &norm_der); - ECDSA_SIG_free(norm_sig); - if (derlen <= 0) - return false; - - // -1 = error, 0 = bad sig, 1 = good - bool ret = ECDSA_verify(0, (unsigned char*)&hash, sizeof(hash), norm_der, derlen, pkey) == 1; - OPENSSL_free(norm_der); - return ret; -} - -bool CECKey::Recover(const uint256 &hash, const unsigned char *p64, int rec) -{ - if (rec<0 || rec>=3) - return false; - ECDSA_SIG *sig = ECDSA_SIG_new(); - BN_bin2bn(&p64[0], 32, sig->r); - BN_bin2bn(&p64[32], 32, sig->s); - bool ret = ECDSA_SIG_recover_key_GFp(pkey, sig, (unsigned char*)&hash, sizeof(hash), rec, 0) == 1; - ECDSA_SIG_free(sig); - return ret; -} - -bool CECKey::TweakPublic(const unsigned char vchTweak[32]) { - bool ret = true; - BN_CTX *ctx = BN_CTX_new(); - BN_CTX_start(ctx); - BIGNUM *bnTweak = BN_CTX_get(ctx); - BIGNUM *bnOrder = BN_CTX_get(ctx); - BIGNUM *bnOne = BN_CTX_get(ctx); - const EC_GROUP *group = EC_KEY_get0_group(pkey); - EC_GROUP_get_order(group, bnOrder, ctx); // what a grossly inefficient way to get the (constant) group order... - BN_bin2bn(vchTweak, 32, bnTweak); - if (BN_cmp(bnTweak, bnOrder) >= 0) - ret = false; // extremely unlikely - EC_POINT *point = EC_POINT_dup(EC_KEY_get0_public_key(pkey), group); - BN_one(bnOne); - EC_POINT_mul(group, point, bnTweak, point, bnOne, ctx); - if (EC_POINT_is_at_infinity(group, point)) - ret = false; // ridiculously unlikely - EC_KEY_set_public_key(pkey, point); - EC_POINT_free(point); - BN_CTX_end(ctx); - BN_CTX_free(ctx); - return ret; -} - -bool CECKey::SanityCheck() -{ - const EC_GROUP *pgroup = ecgroup_order::get(); - if(pgroup == NULL) - return false; - // TODO Is there more EC functionality that could be missing? - return true; -} |