Merge tag 'branch-0.13' into bugfix_gitdir

1 files changed, 171 insertions, 63 deletions

diff --git a/src/key.cpp b/src/key.cpp
index acf62360a4..79023566c3 100644
--- a/src/key.cpp
+++ b/src/key.cpp
@@ -1,48 +1,138 @@
-// Copyright (c) 2009-2014 The Bitcoin developers
+// 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 "crypto/rfc6979_hmac_sha256.h"
-#include "eccryptoverify.h"
 #include "pubkey.h"
 #include "random.h"
 
 #include <secp256k1.h>
-#include "ecwrapper.h"
+#include <secp256k1_recovery.h>
 
-//! anonymous namespace
-namespace {
+static secp256k1_context* secp256k1_context_sign = NULL;
 
-class CSecp256k1Init {
-public:
-    CSecp256k1Init() {
-        secp256k1_start(SECP256K1_START_SIGN);
+/** 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;
     }
-    ~CSecp256k1Init() {
-        secp256k1_stop();
+    privkey++;
+    /* sequence length constructor */
+    if (end < privkey+1 || !(*privkey & 0x80)) {
+        return 0;
     }
-};
-static CSecp256k1Init instance_of_csecp256k1;
+    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;
+}
 
-} // anon namespace
+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 eccrypto::Check(vch);
+    return secp256k1_ec_seckey_verify(secp256k1_context_sign, vch);
 }
 
 void CKey::MakeNewKey(bool fCompressedIn) {
     do {
-        GetRandBytes(vch, sizeof(vch));
+        GetStrongRandBytes(vch, sizeof(vch));
     } while (!Check(vch));
     fValid = true;
     fCompressed = fCompressedIn;
 }
 
 bool CKey::SetPrivKey(const CPrivKey &privkey, bool fCompressedIn) {
-    if (!secp256k1_ec_privkey_import((unsigned char*)begin(), &privkey[0], privkey.size()))
+    if (!ec_privkey_import_der(secp256k1_context_sign, (unsigned char*)begin(), &privkey[0], privkey.size()))
         return false;
     fCompressed = fCompressedIn;
     fValid = true;
@@ -52,10 +142,11 @@ bool CKey::SetPrivKey(const CPrivKey &privkey, bool fCompressedIn) {
 CPrivKey CKey::GetPrivKey() const {
     assert(fValid);
     CPrivKey privkey;
-    int privkeylen, ret;
+    int ret;
+    size_t privkeylen;
     privkey.resize(279);
     privkeylen = 279;
-    ret = secp256k1_ec_privkey_export(begin(), (unsigned char*)&privkey[0], &privkeylen, fCompressed);
+    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;
@@ -63,11 +154,13 @@ CPrivKey CKey::GetPrivKey() const {
 
 CPubKey CKey::GetPubKey() const {
     assert(fValid);
+    secp256k1_pubkey pubkey;
+    size_t clen = 65;
     CPubKey result;
-    int clen = 65;
-    int ret = secp256k1_ec_pubkey_create((unsigned char*)result.begin(), &clen, begin(), fCompressed);
-    assert((int)result.size() == clen);
+    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;
 }
@@ -76,19 +169,15 @@ bool CKey::Sign(const uint256 &hash, std::vector<unsigned char>& vchSig, uint32_
     if (!fValid)
         return false;
     vchSig.resize(72);
-    RFC6979_HMAC_SHA256 prng(begin(), 32, (unsigned char*)&hash, 32);
-    do {
-        uint256 nonce;
-        prng.Generate((unsigned char*)&nonce, 32);
-        nonce += test_case;
-        int nSigLen = 72;
-        int ret = secp256k1_ecdsa_sign((const unsigned char*)&hash, 32, (unsigned char*)&vchSig[0], &nSigLen, begin(), (unsigned char*)&nonce);
-        nonce = 0;
-        if (ret) {
-            vchSig.resize(nSigLen);
-            return true;
-        }
-    } while(true);
+    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 {
@@ -99,7 +188,7 @@ bool CKey::VerifyPubKey(const CPubKey& pubkey) const {
     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((unsigned char*)&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);
@@ -110,22 +199,18 @@ bool CKey::SignCompact(const uint256 &hash, std::vector<unsigned char>& vchSig)
         return false;
     vchSig.resize(65);
     int rec = -1;
-    RFC6979_HMAC_SHA256 prng(begin(), 32, (unsigned char*)&hash, 32);
-    do {
-        uint256 nonce;
-        prng.Generate((unsigned char*)&nonce, 32);
-        int ret = secp256k1_ecdsa_sign_compact((const unsigned char*)&hash, 32, &vchSig[1], begin(), (unsigned char*)&nonce, &rec);
-        nonce = 0;
-        if (ret)
-            break;
-    } while(true);
+    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 (!secp256k1_ec_privkey_import((unsigned char*)begin(), &privkey[0], privkey.size()))
+    if (!ec_privkey_import_der(secp256k1_context_sign, (unsigned char*)begin(), &privkey[0], privkey.size()))
         return false;
     fCompressed = vchPubKey.IsCompressed();
     fValid = true;
@@ -136,7 +221,7 @@ bool CKey::Load(CPrivKey &privkey, CPubKey &vchPubKey, bool fSkipCheck=false) {
     return VerifyPubKey(vchPubKey);
 }
 
-bool CKey::Derive(CKey& keyChild, unsigned char ccChild[32], unsigned int nChild, const unsigned char cc[32]) const {
+bool CKey::Derive(CKey& keyChild, ChainCode &ccChild, unsigned int nChild, const ChainCode& cc) const {
     assert(IsValid());
     assert(IsCompressed());
     unsigned char out[64];
@@ -149,9 +234,9 @@ bool CKey::Derive(CKey& keyChild, unsigned char ccChild[32], unsigned int nChild
         assert(begin() + 32 == end());
         BIP32Hash(cc, nChild, 0, begin(), out);
     }
-    memcpy(ccChild, out+32, 32);
+    memcpy(ccChild.begin(), out+32, 32);
     memcpy((unsigned char*)keyChild.begin(), begin(), 32);
-    bool ret = secp256k1_ec_privkey_tweak_add((unsigned char*)keyChild.begin(), out);
+    bool ret = secp256k1_ec_privkey_tweak_add(secp256k1_context_sign, (unsigned char*)keyChild.begin(), out);
     UnlockObject(out);
     keyChild.fCompressed = true;
     keyChild.fValid = ret;
@@ -163,7 +248,7 @@ bool CExtKey::Derive(CExtKey &out, unsigned int nChild) const {
     CKeyID id = key.GetPubKey().GetID();
     memcpy(&out.vchFingerprint[0], &id, 4);
     out.nChild = nChild;
-    return key.Derive(out.key, out.vchChainCode, nChild, vchChainCode);
+    return key.Derive(out.key, out.chaincode, nChild, chaincode);
 }
 
 void CExtKey::SetMaster(const unsigned char *seed, unsigned int nSeedLen) {
@@ -172,7 +257,7 @@ void CExtKey::SetMaster(const unsigned char *seed, unsigned int nSeedLen) {
     LockObject(out);
     CHMAC_SHA512(hashkey, sizeof(hashkey)).Write(seed, nSeedLen).Finalize(out);
     key.Set(&out[0], &out[32], true);
-    memcpy(vchChainCode, &out[32], 32);
+    memcpy(chaincode.begin(), &out[32], 32);
     UnlockObject(out);
     nDepth = 0;
     nChild = 0;
@@ -185,37 +270,60 @@ CExtPubKey CExtKey::Neuter() const {
     memcpy(&ret.vchFingerprint[0], &vchFingerprint[0], 4);
     ret.nChild = nChild;
     ret.pubkey = key.GetPubKey();
-    memcpy(&ret.vchChainCode[0], &vchChainCode[0], 32);
+    ret.chaincode = chaincode;
     return ret;
 }
 
-void CExtKey::Encode(unsigned char code[74]) const {
+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, vchChainCode, 32);
+    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]) {
+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(vchChainCode, code+9, 32);
-    key.Set(code+42, code+74, true);
+    memcpy(chaincode.begin(), code+9, 32);
+    key.Set(code+42, code+BIP32_EXTKEY_SIZE, true);
 }
 
 bool ECC_InitSanityCheck() {
-#if !defined(USE_SECP256K1)
-    if (!CECKey::SanityCheck()) {
-        return false;
-    }
-#endif
     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);
+    }
+}