Specify ECDSA constant sizes as constants

This commit is contained in:
Jack Grigg 2017-06-06 19:21:34 +12:00
parent e4a10860a4
commit 17fa3913ef
No known key found for this signature in database
GPG Key ID: 665DBCD284F7DAFF
4 changed files with 44 additions and 33 deletions

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@ -87,9 +87,13 @@ static int ec_privkey_import_der(const secp256k1_context* ctx, unsigned char *ou
* <http://www.secg.org/sec1-v2.pdf>. The optional parameters and publicKey fields are
* included.
*
* privkey must point to an output buffer of length at least PRIVATE_KEY_SIZE bytes.
* privkeylen must initially be set to the size of the privkey buffer. Upon return it
* will be set to the number of bytes used in the buffer.
* key32 must point to a 32-byte raw private key.
*/
static int ec_privkey_export_der(const secp256k1_context *ctx, unsigned char *privkey, size_t *privkeylen, const unsigned char *key32, int compressed) {
assert(*privkeylen >= PRIVATE_KEY_SIZE);
secp256k1_pubkey pubkey;
size_t pubkeylen = 0;
if (!secp256k1_ec_pubkey_create(ctx, &pubkey, key32)) {
@ -115,10 +119,11 @@ static int ec_privkey_export_der(const secp256k1_context *ctx, unsigned char *pr
memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
memcpy(ptr, key32, 32); ptr += 32;
memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
pubkeylen = 33;
pubkeylen = COMPRESSED_PUBLIC_KEY_SIZE;
secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_COMPRESSED);
ptr += pubkeylen;
*privkeylen = ptr - privkey;
assert(*privkeylen == COMPRESSED_PRIVATE_KEY_SIZE);
} else {
static const unsigned char begin[] = {
0x30,0x82,0x01,0x13,0x02,0x01,0x01,0x04,0x20
@ -140,10 +145,11 @@ static int ec_privkey_export_der(const secp256k1_context *ctx, unsigned char *pr
memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
memcpy(ptr, key32, 32); ptr += 32;
memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
pubkeylen = 65;
pubkeylen = PUBLIC_KEY_SIZE;
secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_UNCOMPRESSED);
ptr += pubkeylen;
*privkeylen = ptr - privkey;
assert(*privkeylen == PRIVATE_KEY_SIZE);
}
return 1;
}
@ -165,8 +171,8 @@ CPrivKey CKey::GetPrivKey() const {
CPrivKey privkey;
int ret;
size_t privkeylen;
privkey.resize(279);
privkeylen = 279;
privkey.resize(PRIVATE_KEY_SIZE);
privkeylen = PRIVATE_KEY_SIZE;
ret = ec_privkey_export_der(secp256k1_context_sign, (unsigned char*) privkey.data(), &privkeylen, begin(), fCompressed ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED);
assert(ret);
privkey.resize(privkeylen);
@ -176,7 +182,7 @@ CPrivKey CKey::GetPrivKey() const {
CPubKey CKey::GetPubKey() const {
assert(fValid);
secp256k1_pubkey pubkey;
size_t clen = 65;
size_t clen = PUBLIC_KEY_SIZE;
CPubKey result;
int ret = secp256k1_ec_pubkey_create(secp256k1_context_sign, &pubkey, begin());
assert(ret);
@ -189,8 +195,8 @@ CPubKey CKey::GetPubKey() const {
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;
vchSig.resize(SIGNATURE_SIZE);
size_t nSigLen = SIGNATURE_SIZE;
unsigned char extra_entropy[32] = {0};
WriteLE32(extra_entropy, test_case);
secp256k1_ecdsa_signature sig;
@ -218,7 +224,7 @@ bool CKey::VerifyPubKey(const CPubKey& pubkey) const {
bool CKey::SignCompact(const uint256 &hash, std::vector<unsigned char>& vchSig) const {
if (!fValid)
return false;
vchSig.resize(65);
vchSig.resize(COMPACT_SIGNATURE_SIZE);
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);
@ -248,7 +254,7 @@ bool CKey::Derive(CKey& keyChild, ChainCode &ccChild, unsigned int nChild, const
std::vector<unsigned char, secure_allocator<unsigned char>> vout(64);
if ((nChild >> 31) == 0) {
CPubKey pubkey = GetPubKey();
assert(pubkey.size() == 33);
assert(pubkey.size() == COMPRESSED_PUBLIC_KEY_SIZE);
BIP32Hash(cc, nChild, *pubkey.begin(), pubkey.begin()+1, vout.data());
} else {
assert(size() == 32);

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@ -1,5 +1,6 @@
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 The Bitcoin Core developers
// Copyright (c) 2017 The Zcash developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
@ -17,17 +18,18 @@
/**
* secp256k1:
* const unsigned int PRIVATE_KEY_SIZE = 279;
* const unsigned int PUBLIC_KEY_SIZE = 65;
* const unsigned int SIGNATURE_SIZE = 72;
*
*/
const unsigned int PRIVATE_KEY_SIZE = 279;
const unsigned int COMPRESSED_PRIVATE_KEY_SIZE = 214;
/**
* see www.keylength.com
* script supports up to 75 for single byte push
*/
/**
* secure_allocator is defined in allocators.h
* CPrivKey is a serialized private key, with all parameters included (279 bytes)
* CPrivKey is a serialized private key, with all parameters included
* (PRIVATE_KEY_SIZE bytes)
*/
typedef std::vector<unsigned char, secure_allocator<unsigned char> > CPrivKey;

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@ -185,7 +185,7 @@ bool CPubKey::Verify(const uint256 &hash, const std::vector<unsigned char>& vchS
}
bool CPubKey::RecoverCompact(const uint256 &hash, const std::vector<unsigned char>& vchSig) {
if (vchSig.size() != 65)
if (vchSig.size() != COMPACT_SIGNATURE_SIZE)
return false;
int recid = (vchSig[0] - 27) & 3;
bool fComp = ((vchSig[0] - 27) & 4) != 0;
@ -197,8 +197,8 @@ bool CPubKey::RecoverCompact(const uint256 &hash, const std::vector<unsigned cha
if (!secp256k1_ecdsa_recover(secp256k1_context_verify, &pubkey, &sig, hash.begin())) {
return false;
}
unsigned char pub[65];
size_t publen = 65;
unsigned char pub[PUBLIC_KEY_SIZE];
size_t publen = PUBLIC_KEY_SIZE;
secp256k1_ec_pubkey_serialize(secp256k1_context_verify, pub, &publen, &pubkey, fComp ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED);
Set(pub, pub + publen);
return true;
@ -218,8 +218,8 @@ bool CPubKey::Decompress() {
if (!secp256k1_ec_pubkey_parse(secp256k1_context_verify, &pubkey, &(*this)[0], size())) {
return false;
}
unsigned char pub[65];
size_t publen = 65;
unsigned char pub[PUBLIC_KEY_SIZE];
size_t publen = PUBLIC_KEY_SIZE;
secp256k1_ec_pubkey_serialize(secp256k1_context_verify, pub, &publen, &pubkey, SECP256K1_EC_UNCOMPRESSED);
Set(pub, pub + publen);
return true;
@ -228,7 +228,7 @@ bool CPubKey::Decompress() {
bool CPubKey::Derive(CPubKey& pubkeyChild, ChainCode &ccChild, unsigned int nChild, const ChainCode& cc) const {
assert(IsValid());
assert((nChild >> 31) == 0);
assert(size() == 33);
assert(size() == COMPRESSED_PUBLIC_KEY_SIZE);
unsigned char out[64];
BIP32Hash(cc, nChild, *begin(), begin()+1, out);
memcpy(ccChild.begin(), out+32, 32);
@ -239,8 +239,8 @@ bool CPubKey::Derive(CPubKey& pubkeyChild, ChainCode &ccChild, unsigned int nChi
if (!secp256k1_ec_pubkey_tweak_add(secp256k1_context_verify, &pubkey, out)) {
return false;
}
unsigned char pub[33];
size_t publen = 33;
unsigned char pub[COMPRESSED_PUBLIC_KEY_SIZE];
size_t publen = COMPRESSED_PUBLIC_KEY_SIZE;
secp256k1_ec_pubkey_serialize(secp256k1_context_verify, pub, &publen, &pubkey, SECP256K1_EC_COMPRESSED);
pubkeyChild.Set(pub, pub + publen);
return true;
@ -252,8 +252,8 @@ void CExtPubKey::Encode(unsigned char code[BIP32_EXTKEY_SIZE]) const {
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);
assert(pubkey.size() == 33);
memcpy(code+41, pubkey.begin(), 33);
assert(pubkey.size() == COMPRESSED_PUBLIC_KEY_SIZE);
memcpy(code+41, pubkey.begin(), COMPRESSED_PUBLIC_KEY_SIZE);
}
void CExtPubKey::Decode(const unsigned char code[BIP32_EXTKEY_SIZE]) {

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@ -1,5 +1,6 @@
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 The Bitcoin Core developers
// Copyright (c) 2017 The Zcash developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
@ -15,10 +16,12 @@
/**
* secp256k1:
* const unsigned int PRIVATE_KEY_SIZE = 279;
* const unsigned int PUBLIC_KEY_SIZE = 65;
* const unsigned int SIGNATURE_SIZE = 72;
*
*/
const unsigned int PUBLIC_KEY_SIZE = 65;
const unsigned int COMPRESSED_PUBLIC_KEY_SIZE = 33;
const unsigned int SIGNATURE_SIZE = 72;
const unsigned int COMPACT_SIGNATURE_SIZE = 65;
/**
* see www.keylength.com
* script supports up to 75 for single byte push
*/
@ -44,15 +47,15 @@ private:
* Just store the serialized data.
* Its length can very cheaply be computed from the first byte.
*/
unsigned char vch[65];
unsigned char vch[PUBLIC_KEY_SIZE];
//! Compute the length of a pubkey with a given first byte.
unsigned int static GetLen(unsigned char chHeader)
{
if (chHeader == 2 || chHeader == 3)
return 33;
return COMPRESSED_PUBLIC_KEY_SIZE;
if (chHeader == 4 || chHeader == 6 || chHeader == 7)
return 65;
return PUBLIC_KEY_SIZE;
return 0;
}
@ -127,7 +130,7 @@ public:
void Unserialize(Stream& s)
{
unsigned int len = ::ReadCompactSize(s);
if (len <= 65) {
if (len <= PUBLIC_KEY_SIZE) {
s.read((char*)vch, len);
} else {
// invalid pubkey, skip available data
@ -166,7 +169,7 @@ public:
//! Check whether this is a compressed public key.
bool IsCompressed() const
{
return size() == 33;
return size() == COMPRESSED_PUBLIC_KEY_SIZE;
}
/**