/src/key.cpp
C++ | 330 lines | 290 code | 30 blank | 10 comment | 44 complexity | d5dd61f1ebe9f54f42a409d7469a6d29 MD5 | raw file
- // Copyright (c) 2009-2015 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 "key.h"
- #include "arith_uint256.h"
- #include "crypto/common.h"
- #include "crypto/hmac_sha512.h"
- #include "pubkey.h"
- #include "random.h"
- #include <secp256k1.h>
- #include <secp256k1_recovery.h>
- static secp256k1_context* secp256k1_context_sign = NULL;
- /** These functions are taken from the libsecp256k1 distribution and are very ugly. */
- static int ec_privkey_import_der(const secp256k1_context* ctx, unsigned char *out32, const unsigned char *privkey, size_t privkeylen) {
- const unsigned char *end = privkey + privkeylen;
- int lenb = 0;
- int len = 0;
- memset(out32, 0, 32);
- /* sequence header */
- if (end < privkey+1 || *privkey != 0x30) {
- return 0;
- }
- privkey++;
- /* sequence length constructor */
- if (end < privkey+1 || !(*privkey & 0x80)) {
- return 0;
- }
- lenb = *privkey & ~0x80; privkey++;
- if (lenb < 1 || lenb > 2) {
- return 0;
- }
- if (end < privkey+lenb) {
- return 0;
- }
- /* sequence length */
- len = privkey[lenb-1] | (lenb > 1 ? privkey[lenb-2] << 8 : 0);
- privkey += lenb;
- if (end < privkey+len) {
- return 0;
- }
- /* sequence element 0: version number (=1) */
- if (end < privkey+3 || privkey[0] != 0x02 || privkey[1] != 0x01 || privkey[2] != 0x01) {
- return 0;
- }
- privkey += 3;
- /* sequence element 1: octet string, up to 32 bytes */
- if (end < privkey+2 || privkey[0] != 0x04 || privkey[1] > 0x20 || end < privkey+2+privkey[1]) {
- return 0;
- }
- memcpy(out32 + 32 - privkey[1], privkey + 2, privkey[1]);
- if (!secp256k1_ec_seckey_verify(ctx, out32)) {
- memset(out32, 0, 32);
- return 0;
- }
- return 1;
- }
- static int ec_privkey_export_der(const secp256k1_context *ctx, unsigned char *privkey, size_t *privkeylen, const unsigned char *key32, int compressed) {
- secp256k1_pubkey pubkey;
- size_t pubkeylen = 0;
- if (!secp256k1_ec_pubkey_create(ctx, &pubkey, key32)) {
- *privkeylen = 0;
- return 0;
- }
- if (compressed) {
- static const unsigned char begin[] = {
- 0x30,0x81,0xD3,0x02,0x01,0x01,0x04,0x20
- };
- static const unsigned char middle[] = {
- 0xA0,0x81,0x85,0x30,0x81,0x82,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,
- 0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
- 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
- 0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,
- 0x21,0x02,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,
- 0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
- 0x17,0x98,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
- 0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,
- 0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x24,0x03,0x22,0x00
- };
- unsigned char *ptr = privkey;
- memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
- memcpy(ptr, key32, 32); ptr += 32;
- memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
- pubkeylen = 33;
- secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_COMPRESSED);
- ptr += pubkeylen;
- *privkeylen = ptr - privkey;
- } else {
- static const unsigned char begin[] = {
- 0x30,0x82,0x01,0x13,0x02,0x01,0x01,0x04,0x20
- };
- static const unsigned char middle[] = {
- 0xA0,0x81,0xA5,0x30,0x81,0xA2,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,
- 0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
- 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
- 0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,
- 0x41,0x04,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,
- 0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
- 0x17,0x98,0x48,0x3A,0xDA,0x77,0x26,0xA3,0xC4,0x65,0x5D,0xA4,0xFB,0xFC,0x0E,0x11,
- 0x08,0xA8,0xFD,0x17,0xB4,0x48,0xA6,0x85,0x54,0x19,0x9C,0x47,0xD0,0x8F,0xFB,0x10,
- 0xD4,0xB8,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
- 0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,
- 0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x44,0x03,0x42,0x00
- };
- unsigned char *ptr = privkey;
- memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
- memcpy(ptr, key32, 32); ptr += 32;
- memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
- pubkeylen = 65;
- secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_UNCOMPRESSED);
- ptr += pubkeylen;
- *privkeylen = ptr - privkey;
- }
- return 1;
- }
- bool CKey::Check(const unsigned char *vch) {
- return secp256k1_ec_seckey_verify(secp256k1_context_sign, vch);
- }
- void CKey::MakeNewKey(bool fCompressedIn) {
- RandAddSeedPerfmon();
- do {
- GetRandBytes(vch, sizeof(vch));
- } while (!Check(vch));
- fValid = true;
- fCompressed = fCompressedIn;
- }
- bool CKey::SetPrivKey(const CPrivKey &privkey, bool fCompressedIn) {
- if (!ec_privkey_import_der(secp256k1_context_sign, (unsigned char*)begin(), &privkey[0], privkey.size()))
- return false;
- fCompressed = fCompressedIn;
- fValid = true;
- return true;
- }
- CPrivKey CKey::GetPrivKey() const {
- assert(fValid);
- CPrivKey privkey;
- int ret;
- size_t privkeylen;
- privkey.resize(279);
- privkeylen = 279;
- ret = ec_privkey_export_der(secp256k1_context_sign, (unsigned char*)&privkey[0], &privkeylen, begin(), fCompressed ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED);
- assert(ret);
- privkey.resize(privkeylen);
- return privkey;
- }
- CPubKey CKey::GetPubKey() const {
- assert(fValid);
- secp256k1_pubkey pubkey;
- size_t clen = 65;
- CPubKey result;
- int ret = secp256k1_ec_pubkey_create(secp256k1_context_sign, &pubkey, begin());
- assert(ret);
- secp256k1_ec_pubkey_serialize(secp256k1_context_sign, (unsigned char*)result.begin(), &clen, &pubkey, fCompressed ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED);
- assert(result.size() == clen);
- assert(result.IsValid());
- return result;
- }
- bool CKey::Sign(const uint256 &hash, std::vector<unsigned char>& vchSig, uint32_t test_case) const {
- if (!fValid)
- return false;
- vchSig.resize(72);
- size_t nSigLen = 72;
- unsigned char extra_entropy[32] = {0};
- WriteLE32(extra_entropy, test_case);
- secp256k1_ecdsa_signature sig;
- int ret = secp256k1_ecdsa_sign(secp256k1_context_sign, &sig, hash.begin(), begin(), secp256k1_nonce_function_rfc6979, test_case ? extra_entropy : NULL);
- assert(ret);
- secp256k1_ecdsa_signature_serialize_der(secp256k1_context_sign, (unsigned char*)&vchSig[0], &nSigLen, &sig);
- vchSig.resize(nSigLen);
- return true;
- }
- bool CKey::VerifyPubKey(const CPubKey& pubkey) const {
- if (pubkey.IsCompressed() != fCompressed) {
- return false;
- }
- unsigned char rnd[8];
- std::string str = "Bitcoin key verification\n";
- GetRandBytes(rnd, sizeof(rnd));
- uint256 hash;
- CHash256().Write((unsigned char*)str.data(), str.size()).Write(rnd, sizeof(rnd)).Finalize(hash.begin());
- std::vector<unsigned char> vchSig;
- Sign(hash, vchSig);
- return pubkey.Verify(hash, vchSig);
- }
- bool CKey::SignCompact(const uint256 &hash, std::vector<unsigned char>& vchSig) const {
- if (!fValid)
- return false;
- vchSig.resize(65);
- int rec = -1;
- secp256k1_ecdsa_recoverable_signature sig;
- int ret = secp256k1_ecdsa_sign_recoverable(secp256k1_context_sign, &sig, hash.begin(), begin(), secp256k1_nonce_function_rfc6979, NULL);
- assert(ret);
- secp256k1_ecdsa_recoverable_signature_serialize_compact(secp256k1_context_sign, (unsigned char*)&vchSig[1], &rec, &sig);
- assert(ret);
- assert(rec != -1);
- vchSig[0] = 27 + rec + (fCompressed ? 4 : 0);
- return true;
- }
- bool CKey::Load(CPrivKey &privkey, CPubKey &vchPubKey, bool fSkipCheck=false) {
- if (!ec_privkey_import_der(secp256k1_context_sign, (unsigned char*)begin(), &privkey[0], privkey.size()))
- return false;
- fCompressed = vchPubKey.IsCompressed();
- fValid = true;
- if (fSkipCheck)
- return true;
- return VerifyPubKey(vchPubKey);
- }
- bool CKey::Derive(CKey& keyChild, ChainCode &ccChild, unsigned int nChild, const ChainCode& cc) const {
- assert(IsValid());
- assert(IsCompressed());
- unsigned char out[64];
- LockObject(out);
- if ((nChild >> 31) == 0) {
- CPubKey pubkey = GetPubKey();
- assert(pubkey.begin() + 33 == pubkey.end());
- BIP32Hash(cc, nChild, *pubkey.begin(), pubkey.begin()+1, out);
- } else {
- assert(begin() + 32 == end());
- BIP32Hash(cc, nChild, 0, begin(), out);
- }
- memcpy(ccChild.begin(), out+32, 32);
- memcpy((unsigned char*)keyChild.begin(), begin(), 32);
- bool ret = secp256k1_ec_privkey_tweak_add(secp256k1_context_sign, (unsigned char*)keyChild.begin(), out);
- UnlockObject(out);
- keyChild.fCompressed = true;
- keyChild.fValid = ret;
- return ret;
- }
- bool CExtKey::Derive(CExtKey &out, unsigned int nChild) const {
- out.nDepth = nDepth + 1;
- CKeyID id = key.GetPubKey().GetID();
- memcpy(&out.vchFingerprint[0], &id, 4);
- out.nChild = nChild;
- return key.Derive(out.key, out.chaincode, nChild, chaincode);
- }
- void CExtKey::SetMaster(const unsigned char *seed, unsigned int nSeedLen) {
- static const unsigned char hashkey[] = {'B','i','t','c','o','i','n',' ','s','e','e','d'};
- unsigned char out[64];
- LockObject(out);
- CHMAC_SHA512(hashkey, sizeof(hashkey)).Write(seed, nSeedLen).Finalize(out);
- key.Set(&out[0], &out[32], true);
- memcpy(chaincode.begin(), &out[32], 32);
- UnlockObject(out);
- nDepth = 0;
- nChild = 0;
- memset(vchFingerprint, 0, sizeof(vchFingerprint));
- }
- CExtPubKey CExtKey::Neuter() const {
- CExtPubKey ret;
- ret.nDepth = nDepth;
- memcpy(&ret.vchFingerprint[0], &vchFingerprint[0], 4);
- ret.nChild = nChild;
- ret.pubkey = key.GetPubKey();
- ret.chaincode = chaincode;
- return ret;
- }
- void CExtKey::Encode(unsigned char code[74]) const {
- code[0] = nDepth;
- memcpy(code+1, vchFingerprint, 4);
- code[5] = (nChild >> 24) & 0xFF; code[6] = (nChild >> 16) & 0xFF;
- code[7] = (nChild >> 8) & 0xFF; code[8] = (nChild >> 0) & 0xFF;
- memcpy(code+9, chaincode.begin(), 32);
- code[41] = 0;
- assert(key.size() == 32);
- memcpy(code+42, key.begin(), 32);
- }
- void CExtKey::Decode(const unsigned char code[74]) {
- nDepth = code[0];
- memcpy(vchFingerprint, code+1, 4);
- nChild = (code[5] << 24) | (code[6] << 16) | (code[7] << 8) | code[8];
- memcpy(chaincode.begin(), code+9, 32);
- key.Set(code+42, code+74, true);
- }
- bool ECC_InitSanityCheck() {
- CKey key;
- key.MakeNewKey(true);
- CPubKey pubkey = key.GetPubKey();
- return key.VerifyPubKey(pubkey);
- }
- void ECC_Start() {
- assert(secp256k1_context_sign == NULL);
- secp256k1_context *ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN);
- assert(ctx != NULL);
- {
- // Pass in a random blinding seed to the secp256k1 context.
- unsigned char seed[32];
- LockObject(seed);
- GetRandBytes(seed, 32);
- bool ret = secp256k1_context_randomize(ctx, seed);
- assert(ret);
- UnlockObject(seed);
- }
- secp256k1_context_sign = ctx;
- }
- void ECC_Stop() {
- secp256k1_context *ctx = secp256k1_context_sign;
- secp256k1_context_sign = NULL;
- if (ctx) {
- secp256k1_context_destroy(ctx);
- }
- }