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-rw-r--r--src/key.cpp461
1 files changed, 225 insertions, 236 deletions
diff --git a/src/key.cpp b/src/key.cpp
index 20114e6bb2..f73708199a 100644
--- a/src/key.cpp
+++ b/src/key.cpp
@@ -2,13 +2,16 @@
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-#include <map>
-
#include <openssl/ecdsa.h>
+#include <openssl/rand.h>
#include <openssl/obj_mac.h>
#include "key.h"
+
+// anonymous namespace with local implementation code (OpenSSL interaction)
+namespace {
+
// Generate a private key from just the secret parameter
int EC_KEY_regenerate_key(EC_KEY *eckey, BIGNUM *priv_key)
{
@@ -120,287 +123,273 @@ err:
return ret;
}
-void CKey::SetCompressedPubKey(bool fCompressed)
-{
- EC_KEY_set_conv_form(pkey, fCompressed ? POINT_CONVERSION_COMPRESSED : POINT_CONVERSION_UNCOMPRESSED);
- fCompressedPubKey = true;
-}
+// RAII Wrapper around OpenSSL's EC_KEY
+class CECKey {
+private:
+ EC_KEY *pkey;
-void CKey::Reset()
-{
- fCompressedPubKey = false;
- if (pkey != NULL)
+public:
+ CECKey() {
+ pkey = EC_KEY_new_by_curve_name(NID_secp256k1);
+ assert(pkey != NULL);
+ }
+
+ ~CECKey() {
EC_KEY_free(pkey);
- 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()
-{
- pkey = NULL;
- Reset();
-}
+ void GetSecretBytes(unsigned char vch[32]) const {
+ const BIGNUM *bn = EC_KEY_get0_private_key(pkey);
+ assert(bn);
+ int nBytes = BN_num_bytes(bn);
+ int n=BN_bn2bin(bn,&vch[32 - nBytes]);
+ assert(n == nBytes);
+ memset(vch, 0, 32 - nBytes);
+ }
-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;
-}
+ void SetSecretBytes(const unsigned char vch[32]) {
+ BIGNUM bn;
+ BN_init(&bn);
+ assert(BN_bin2bn(vch, 32, &bn));
+ assert(EC_KEY_regenerate_key(pkey, &bn));
+ BN_clear_free(&bn);
+ }
-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);
-}
+ void GetPrivKey(CPrivKey &privkey) {
+ int nSize = i2d_ECPrivateKey(pkey, NULL);
+ assert(nSize);
+ privkey.resize(nSize);
+ unsigned char* pbegin = &privkey[0];
+ int nSize2 = i2d_ECPrivateKey(pkey, &pbegin);
+ assert(nSize == nSize2);
+ }
-CKey::~CKey()
-{
- EC_KEY_free(pkey);
-}
+ bool SetPrivKey(const CPrivKey &privkey) {
+ const unsigned char* pbegin = &privkey[0];
+ if (d2i_ECPrivateKey(&pkey, &pbegin, privkey.size())) {
+ // d2i_ECPrivateKey returns true if parsing succeeds.
+ // This doesn't necessarily mean the key is valid.
+ if (EC_KEY_check_key(pkey))
+ return true;
+ }
+ return false;
+ }
-bool CKey::IsNull() const
-{
- return !fSet;
-}
+ void GetPubKey(CPubKey &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);
+ unsigned char c[65];
+ unsigned char *pbegin = c;
+ int nSize2 = i2o_ECPublicKey(pkey, &pbegin);
+ assert(nSize == nSize2);
+ pubkey.Set(&c[0], &c[nSize]);
+ }
-bool CKey::IsCompressed() const
-{
- return fCompressedPubKey;
-}
+ bool SetPubKey(const CPubKey &pubkey) {
+ const unsigned char* pbegin = pubkey.begin();
+ return o2i_ECPublicKey(&pkey, &pbegin, pubkey.size());
+ }
-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 Sign(const uint256 &hash, std::vector<unsigned char>& vchSig) {
+ unsigned int nSize = ECDSA_size(pkey);
+ vchSig.resize(nSize); // Make sure it is big enough
+ assert(ECDSA_sign(0, (unsigned char*)&hash, sizeof(hash), &vchSig[0], &nSize, pkey));
+ vchSig.resize(nSize); // Shrink to fit actual size
+ return true;
+ }
-bool CKey::SetPrivKey(const CPrivKey& vchPrivKey)
-{
- const unsigned char* pbegin = &vchPrivKey[0];
- if (d2i_ECPrivateKey(&pkey, &pbegin, vchPrivKey.size()))
- {
- // In testing, d2i_ECPrivateKey can return true
- // but fill in pkey with a key that fails
- // EC_KEY_check_key, so:
- if (EC_KEY_check_key(pkey))
- {
- fSet = true;
- return true;
+ bool Verify(const uint256 &hash, const std::vector<unsigned char>& vchSig) {
+ // -1 = error, 0 = bad sig, 1 = good
+ if (ECDSA_verify(0, (unsigned char*)&hash, sizeof(hash), &vchSig[0], vchSig.size(), pkey) != 1)
+ return false;
+ return true;
+ }
+
+ bool SignCompact(const uint256 &hash, unsigned char *p64, int &rec) {
+ bool fOk = false;
+ ECDSA_SIG *sig = ECDSA_do_sign((unsigned char*)&hash, sizeof(hash), pkey);
+ if (sig==NULL)
+ return false;
+ memset(p64, 0, 64);
+ int nBitsR = BN_num_bits(sig->r);
+ int nBitsS = BN_num_bits(sig->s);
+ if (nBitsR <= 256 && nBitsS <= 256) {
+ CPubKey pubkey;
+ GetPubKey(pubkey, true);
+ for (int i=0; i<4; i++) {
+ CECKey keyRec;
+ if (ECDSA_SIG_recover_key_GFp(keyRec.pkey, sig, (unsigned char*)&hash, sizeof(hash), i, 1) == 1) {
+ CPubKey pubkeyRec;
+ keyRec.GetPubKey(pubkeyRec, true);
+ if (pubkeyRec == pubkey) {
+ rec = i;
+ fOk = true;
+ break;
+ }
+ }
+ }
+ assert(fOk);
+ BN_bn2bin(sig->r,&p64[32-(nBitsR+7)/8]);
+ BN_bn2bin(sig->s,&p64[64-(nBitsS+7)/8]);
}
+ ECDSA_SIG_free(sig);
+ return fOk;
}
- // If vchPrivKey data is bad d2i_ECPrivateKey() can
- // leave pkey in a state where calling EC_KEY_free()
- // crashes. To avoid that, set pkey to NULL and
- // leak the memory (a leak is better than a crash)
- pkey = NULL;
- Reset();
- return false;
-}
-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))
+ // 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 Recover(const uint256 &hash, const unsigned char *p64, int rec)
{
- BN_clear_free(bn);
- throw key_error("CKey::SetSecret() : EC_KEY_regenerate_key failed");
+ 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;
+ }
+};
+
+}; // end of anonymous namespace
+
+bool CKey::Check(const unsigned char *vch) {
+ // Do not convert to OpenSSL's data structures for range-checking keys,
+ // it's easy enough to do directly.
+ static const unsigned char vchMax[32] = {
+ 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,0xD0,0x36,0x41,0x40
+ };
+ bool fIsZero = true;
+ for (int i=0; i<32 && fIsZero; i++)
+ if (vch[i] != 0)
+ fIsZero = false;
+ if (fIsZero)
+ return false;
+ for (int i=0; i<32; i++) {
+ if (vch[i] < vchMax[i])
+ return true;
+ if (vch[i] > vchMax[i])
+ return false;
}
- 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;
+void CKey::MakeNewKey(bool fCompressedIn) {
+ do {
+ RAND_bytes(vch, sizeof(vch));
+ } while (!Check(vch));
+ fValid = true;
+ fCompressed = fCompressedIn;
}
-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::SetPrivKey(const CPrivKey &privkey, bool fCompressedIn) {
+ CECKey key;
+ if (!key.SetPrivKey(privkey))
+ return false;
+ key.GetSecretBytes(vch);
+ fCompressed = fCompressedIn;
+ fValid = true;
+ return true;
}
-bool CKey::SetPubKey(const CPubKey& vchPubKey)
-{
- const unsigned char* pbegin = &vchPubKey.vchPubKey[0];
- if (o2i_ECPublicKey(&pkey, &pbegin, vchPubKey.vchPubKey.size()))
- {
- fSet = true;
- if (vchPubKey.vchPubKey.size() == 33)
- SetCompressedPubKey();
- return true;
- }
- pkey = NULL;
- Reset();
- return false;
+CPrivKey CKey::GetPrivKey() const {
+ assert(fValid);
+ CECKey key;
+ key.SetSecretBytes(vch);
+ CPrivKey privkey;
+ key.GetPrivKey(privkey);
+ return privkey;
}
-CPubKey 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 CPubKey(vchPubKey);
+CPubKey CKey::GetPubKey() const {
+ assert(fValid);
+ CECKey key;
+ key.SetSecretBytes(vch);
+ CPubKey pubkey;
+ key.GetPubKey(pubkey, fCompressed);
+ return pubkey;
}
-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();
+bool CKey::Sign(const uint256 &hash, std::vector<unsigned char>& vchSig) const {
+ if (!fValid)
return false;
- }
- vchSig.resize(nSize); // Shrink to fit actual size
- return true;
+ CECKey key;
+ key.SetSecretBytes(vch);
+ return key.Sign(hash, vchSig);
}
-// 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)
+bool CKey::SignCompact(const uint256 &hash, std::vector<unsigned char>& vchSig) const {
+ if (!fValid)
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");
+ CECKey key;
+ key.SetSecretBytes(vch);
+ vchSig.resize(65);
+ int rec = -1;
+ if (!key.SignCompact(hash, &vchSig[1], rec))
+ return false;
+ assert(rec != -1);
+ vchSig[0] = 27 + rec + (fCompressed ? 4 : 0);
+ return true;
+}
- 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;
+bool CPubKey::Verify(const uint256 &hash, const std::vector<unsigned char>& vchSig) const {
+ if (!IsValid())
+ return false;
+ CECKey key;
+ if (!key.SetPubKey(*this))
+ return false;
+ if (!key.Verify(hash, vchSig))
+ return false;
+ return true;
}
-// 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)
-{
+bool CPubKey::RecoverCompact(const uint256 &hash, const std::vector<unsigned char>& vchSig) {
if (vchSig.size() != 65)
return false;
- int nV = vchSig[0];
- if (nV<27 || nV>=35)
+ CECKey key;
+ if (!key.Recover(hash, &vchSig[1], (vchSig[0] - 27) & ~4))
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;
+ key.GetPubKey(*this, (vchSig[0] - 27) & 4);
+ return true;
}
-bool CKey::Verify(uint256 hash, const std::vector<unsigned char>& vchSig)
-{
- // -1 = error, 0 = bad sig, 1 = good
- if (ECDSA_verify(0, (unsigned char*)&hash, sizeof(hash), &vchSig[0], vchSig.size(), pkey) != 1)
+bool CPubKey::VerifyCompact(const uint256 &hash, const std::vector<unsigned char>& vchSig) const {
+ if (!IsValid())
+ return false;
+ if (vchSig.size() != 65)
+ return false;
+ CECKey key;
+ if (!key.Recover(hash, &vchSig[1], (vchSig[0] - 27) & ~4))
+ return false;
+ CPubKey pubkeyRec;
+ key.GetPubKey(pubkeyRec, IsCompressed());
+ if (*this != pubkeyRec)
return false;
-
return true;
}
-bool CKey::VerifyCompact(uint256 hash, const std::vector<unsigned char>& vchSig)
-{
- CKey key;
- if (!key.SetCompactSignature(hash, vchSig))
+bool CPubKey::IsFullyValid() const {
+ if (!IsValid())
return false;
- if (GetPubKey() != key.GetPubKey())
+ CECKey key;
+ if (!key.SetPubKey(*this))
return false;
-
return true;
}
-bool CKey::IsValid()
-{
- if (!fSet)
+bool CPubKey::Decompress() {
+ if (!IsValid())
return false;
-
- if (!EC_KEY_check_key(pkey))
+ CECKey key;
+ if (!key.SetPubKey(*this))
return false;
-
- bool fCompr;
- CSecret secret = GetSecret(fCompr);
- CKey key2;
- key2.SetSecret(secret, fCompr);
- return GetPubKey() == key2.GetPubKey();
+ key.GetPubKey(*this, false);
+ return true;
}