diff options
Diffstat (limited to 'src/key.cpp')
| -rw-r--r-- | src/key.cpp | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/src/key.cpp b/src/key.cpp new file mode 100644 index 000000000..79023566c --- /dev/null +++ b/src/key.cpp @@ -0,0 +1,329 @@ +// 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) { + do { + GetStrongRandBytes(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[BIP32_EXTKEY_SIZE]) 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[BIP32_EXTKEY_SIZE]) { + 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+BIP32_EXTKEY_SIZE, 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); + } +} |