Merge branch 'optimize'

1 files changed, 331 insertions, 1 deletions

diff --git a/src/key.cpp b/src/key.cpp
index dab1eed2eb..4172d6be5e 100644
--- a/src/key.cpp
+++ b/src/key.cpp
@@ -2,8 +2,15 @@
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <openssl/ec.h>
+#include <map>
+
+#include <boost/tuple/tuple.hpp>
 #include <openssl/ecdsa.h>
+#include <openssl/obj_mac.h>
+
+#include "key.h"
+#include "sync.h"
+#include "util.h"
 
 // Generate a private key from just the secret parameter
 int EC_KEY_regenerate_key(EC_KEY *eckey, BIGNUM *priv_key)
@@ -115,3 +122,326 @@ err:
     if (Q != NULL) EC_POINT_free(Q);
     return ret;
 }
+
+void CKey::SetCompressedPubKey()
+{
+    EC_KEY_set_conv_form(pkey, POINT_CONVERSION_COMPRESSED);
+    fCompressedPubKey = true;
+}
+
+void CKey::Reset()
+{
+    fCompressedPubKey = false;
+    pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
+    if (pkey == NULL)
+        throw key_error("CKey::CKey() : EC_KEY_new_by_curve_name failed");
+    fSet = false;
+}
+
+CKey::CKey()
+{
+    Reset();
+}
+
+CKey::CKey(const CKey& b)
+{
+    pkey = EC_KEY_dup(b.pkey);
+    if (pkey == NULL)
+        throw key_error("CKey::CKey(const CKey&) : EC_KEY_dup failed");
+    fSet = b.fSet;
+}
+
+CKey& CKey::operator=(const CKey& b)
+{
+    if (!EC_KEY_copy(pkey, b.pkey))
+        throw key_error("CKey::operator=(const CKey&) : EC_KEY_copy failed");
+    fSet = b.fSet;
+    return (*this);
+}
+
+CKey::~CKey()
+{
+    EC_KEY_free(pkey);
+}
+
+bool CKey::IsNull() const
+{
+    return !fSet;
+}
+
+bool CKey::IsCompressed() const
+{
+    return fCompressedPubKey;
+}
+
+void CKey::MakeNewKey(bool fCompressed)
+{
+    if (!EC_KEY_generate_key(pkey))
+        throw key_error("CKey::MakeNewKey() : EC_KEY_generate_key failed");
+    if (fCompressed)
+        SetCompressedPubKey();
+    fSet = true;
+}
+
+bool CKey::SetPrivKey(const CPrivKey& vchPrivKey)
+{
+    const unsigned char* pbegin = &vchPrivKey[0];
+    if (!d2i_ECPrivateKey(&pkey, &pbegin, vchPrivKey.size()))
+        return false;
+    fSet = true;
+    return true;
+}
+
+bool CKey::SetSecret(const CSecret& vchSecret, bool fCompressed)
+{
+    EC_KEY_free(pkey);
+    pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
+    if (pkey == NULL)
+        throw key_error("CKey::SetSecret() : EC_KEY_new_by_curve_name failed");
+    if (vchSecret.size() != 32)
+        throw key_error("CKey::SetSecret() : secret must be 32 bytes");
+    BIGNUM *bn = BN_bin2bn(&vchSecret[0],32,BN_new());
+    if (bn == NULL)
+        throw key_error("CKey::SetSecret() : BN_bin2bn failed");
+    if (!EC_KEY_regenerate_key(pkey,bn))
+    {
+        BN_clear_free(bn);
+        throw key_error("CKey::SetSecret() : EC_KEY_regenerate_key failed");
+    }
+    BN_clear_free(bn);
+    fSet = true;
+    if (fCompressed || fCompressedPubKey)
+        SetCompressedPubKey();
+    return true;
+}
+
+CSecret CKey::GetSecret(bool &fCompressed) const
+{
+    CSecret vchRet;
+    vchRet.resize(32);
+    const BIGNUM *bn = EC_KEY_get0_private_key(pkey);
+    int nBytes = BN_num_bytes(bn);
+    if (bn == NULL)
+        throw key_error("CKey::GetSecret() : EC_KEY_get0_private_key failed");
+    int n=BN_bn2bin(bn,&vchRet[32 - nBytes]);
+    if (n != nBytes)
+        throw key_error("CKey::GetSecret(): BN_bn2bin failed");
+    fCompressed = fCompressedPubKey;
+    return vchRet;
+}
+
+CPrivKey CKey::GetPrivKey() const
+{
+    int nSize = i2d_ECPrivateKey(pkey, NULL);
+    if (!nSize)
+        throw key_error("CKey::GetPrivKey() : i2d_ECPrivateKey failed");
+    CPrivKey vchPrivKey(nSize, 0);
+    unsigned char* pbegin = &vchPrivKey[0];
+    if (i2d_ECPrivateKey(pkey, &pbegin) != nSize)
+        throw key_error("CKey::GetPrivKey() : i2d_ECPrivateKey returned unexpected size");
+    return vchPrivKey;
+}
+
+bool CKey::SetPubKey(const std::vector<unsigned char>& vchPubKey)
+{
+    const unsigned char* pbegin = &vchPubKey[0];
+    if (!o2i_ECPublicKey(&pkey, &pbegin, vchPubKey.size()))
+        return false;
+    fSet = true;
+    if (vchPubKey.size() == 33)
+        SetCompressedPubKey();
+    return true;
+}
+
+std::vector<unsigned char> CKey::GetPubKey() const
+{
+    int nSize = i2o_ECPublicKey(pkey, NULL);
+    if (!nSize)
+        throw key_error("CKey::GetPubKey() : i2o_ECPublicKey failed");
+    std::vector<unsigned char> vchPubKey(nSize, 0);
+    unsigned char* pbegin = &vchPubKey[0];
+    if (i2o_ECPublicKey(pkey, &pbegin) != nSize)
+        throw key_error("CKey::GetPubKey() : i2o_ECPublicKey returned unexpected size");
+    return vchPubKey;
+}
+
+bool CKey::Sign(uint256 hash, std::vector<unsigned char>& vchSig)
+{
+    unsigned int nSize = ECDSA_size(pkey);
+    vchSig.resize(nSize); // Make sure it is big enough
+    if (!ECDSA_sign(0, (unsigned char*)&hash, sizeof(hash), &vchSig[0], &nSize, pkey))
+    {
+        vchSig.clear();
+        return false;
+    }
+    vchSig.resize(nSize); // Shrink to fit actual size
+    return true;
+}
+
+// create a compact signature (65 bytes), which allows reconstructing the used public key
+// The format is one header byte, followed by two times 32 bytes for the serialized r and s values.
+// The header byte: 0x1B = first key with even y, 0x1C = first key with odd y,
+//                  0x1D = second key with even y, 0x1E = second key with odd y
+bool CKey::SignCompact(uint256 hash, std::vector<unsigned char>& vchSig)
+{
+    bool fOk = false;
+    ECDSA_SIG *sig = ECDSA_do_sign((unsigned char*)&hash, sizeof(hash), pkey);
+    if (sig==NULL)
+        return false;
+    vchSig.clear();
+    vchSig.resize(65,0);
+    int nBitsR = BN_num_bits(sig->r);
+    int nBitsS = BN_num_bits(sig->s);
+    if (nBitsR <= 256 && nBitsS <= 256)
+    {
+        int nRecId = -1;
+        for (int i=0; i<4; i++)
+        {
+            CKey keyRec;
+            keyRec.fSet = true;
+            if (fCompressedPubKey)
+                keyRec.SetCompressedPubKey();
+            if (ECDSA_SIG_recover_key_GFp(keyRec.pkey, sig, (unsigned char*)&hash, sizeof(hash), i, 1) == 1)
+                if (keyRec.GetPubKey() == this->GetPubKey())
+                {
+                    nRecId = i;
+                    break;
+                }
+        }
+
+        if (nRecId == -1)
+            throw key_error("CKey::SignCompact() : unable to construct recoverable key");
+
+        vchSig[0] = nRecId+27+(fCompressedPubKey ? 4 : 0);
+        BN_bn2bin(sig->r,&vchSig[33-(nBitsR+7)/8]);
+        BN_bn2bin(sig->s,&vchSig[65-(nBitsS+7)/8]);
+        fOk = true;
+    }
+    ECDSA_SIG_free(sig);
+    return fOk;
+}
+
+// reconstruct public key from a compact signature
+// This is only slightly more CPU intensive than just verifying it.
+// If this function succeeds, the recovered public key is guaranteed to be valid
+// (the signature is a valid signature of the given data for that key)
+bool CKey::SetCompactSignature(uint256 hash, const std::vector<unsigned char>& vchSig)
+{
+    if (vchSig.size() != 65)
+        return false;
+    int nV = vchSig[0];
+    if (nV<27 || nV>=35)
+        return false;
+    ECDSA_SIG *sig = ECDSA_SIG_new();
+    BN_bin2bn(&vchSig[1],32,sig->r);
+    BN_bin2bn(&vchSig[33],32,sig->s);
+
+    EC_KEY_free(pkey);
+    pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
+    if (nV >= 31)
+    {
+        SetCompressedPubKey();
+        nV -= 4;
+    }
+    if (ECDSA_SIG_recover_key_GFp(pkey, sig, (unsigned char*)&hash, sizeof(hash), nV - 27, 0) == 1)
+    {
+        fSet = true;
+        ECDSA_SIG_free(sig);
+        return true;
+    }
+    return false;
+}
+
+// Valid signature cache, to avoid doing expensive ECDSA signature checking
+// twice for every transaction (once when accepted into memory pool, and
+// again when accepted into the block chain)
+
+// sigdata_type is (signature hash, signature, public key):
+typedef boost::tuple<uint256, std::vector<unsigned char>, std::vector<unsigned char> > sigdata_type;
+static std::set< sigdata_type> setValidSigCache;
+static CCriticalSection cs_sigcache;
+
+static bool
+GetValidSigCache(uint256 hash, const std::vector<unsigned char>& vchSig, const std::vector<unsigned char>& pubKey)
+{
+    LOCK(cs_sigcache);
+
+    sigdata_type k(hash, vchSig, pubKey);
+    std::set<sigdata_type>::iterator mi = setValidSigCache.find(k);
+    if (mi != setValidSigCache.end())
+        return true;
+    return false;
+}
+
+static void
+SetValidSigCache(uint256 hash, const std::vector<unsigned char>& vchSig, const std::vector<unsigned char>& pubKey)
+{
+    // DoS prevention: limit cache size to less than 10MB
+    // (~200 bytes per cache entry times 50,000 entries)
+    // Since there are a maximum of 20,000 signature operations per block
+    // 50,000 is a reasonable default.
+    int64 nMaxCacheSize = GetArg("-maxsigcachesize", 50000);
+    if (nMaxCacheSize <= 0) return;
+
+    LOCK(cs_sigcache);
+
+    while (setValidSigCache.size() > nMaxCacheSize)
+    {
+        // Evict a random entry. Random because that helps
+        // foil would-be DoS attackers who might try to pre-generate
+        // and re-use a set of valid signatures just-slightly-greater
+        // than our cache size.
+        uint256 randomHash = GetRandHash();
+        std::vector<unsigned char> unused;
+        std::set<sigdata_type>::iterator it =
+            setValidSigCache.lower_bound(sigdata_type(randomHash, unused, unused));
+        if (it == setValidSigCache.end())
+            it = setValidSigCache.begin();
+        setValidSigCache.erase(*it);
+    }
+
+    sigdata_type k(hash, vchSig, pubKey);
+    setValidSigCache.insert(k);
+}
+
+
+bool CKey::Verify(uint256 hash, const std::vector<unsigned char>& vchSig)
+{
+    if (GetValidSigCache(hash, vchSig, GetPubKey()))
+        return true;
+
+    // -1 = error, 0 = bad sig, 1 = good
+    if (ECDSA_verify(0, (unsigned char*)&hash, sizeof(hash), &vchSig[0], vchSig.size(), pkey) != 1)
+        return false;
+
+    // good sig
+    SetValidSigCache(hash, vchSig, GetPubKey());
+    return true;
+}
+
+bool CKey::VerifyCompact(uint256 hash, const std::vector<unsigned char>& vchSig)
+{
+    if (GetValidSigCache(hash, vchSig, GetPubKey()))
+        return true;
+
+    CKey key;
+    if (!key.SetCompactSignature(hash, vchSig))
+        return false;
+    if (GetPubKey() != key.GetPubKey())
+        return false;
+
+    SetValidSigCache(hash, vchSig, GetPubKey());
+    return true;
+}
+
+bool CKey::IsValid()
+{
+    if (!fSet)
+        return false;
+
+    bool fCompr;
+    CSecret secret = GetSecret(fCompr);
+    CKey key2;
+    key2.SetSecret(secret, fCompr);
+    return GetPubKey() == key2.GetPubKey();
+}