diff options
| -rw-r--r-- | node/Identity.cpp | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/node/Identity.cpp b/node/Identity.cpp index 2efed293..8dc192ca 100644 --- a/node/Identity.cpp +++ b/node/Identity.cpp @@ -43,10 +43,9 @@ namespace ZeroTier { -static inline void _computeMemoryHardHash(const void *publicKey,unsigned int publicKeyBytes,void *sha512digest) +// A memory-hard composition of SHA-512 and Salsa20 for hashcash hashing +static inline void _computeMemoryHardHash(const void *publicKey,unsigned int publicKeyBytes,void *sha512digest,unsigned char *genmem) { - unsigned char genmem[ZT_IDENTITY_GEN_MEMORY]; - // Step 1: hash key to generate Salsa20 key and nonce SHA512::hash(sha512digest,publicKey,publicKeyBytes); @@ -61,28 +60,29 @@ static inline void _computeMemoryHardHash(const void *publicKey,unsigned int pub SHA512::hash(sha512digest,genmem,ZT_IDENTITY_GEN_MEMORY); } +// Hashcash generation halting condition -- halt when first byte is less than +// threshold value. struct _Identity_generate_cond { _Identity_generate_cond() throw() {} - _Identity_generate_cond(unsigned char *sb) throw() : sha512digest(sb) {} - + _Identity_generate_cond(unsigned char *sb,unsigned char *gm) throw() : sha512digest(sb),genmem(gm) {} inline bool operator()(const C25519::Pair &kp) const throw() { - _computeMemoryHardHash(kp.pub.data,kp.pub.size(),sha512digest); + _computeMemoryHardHash(kp.pub.data,kp.pub.size(),sha512digest,genmem); return (sha512digest[0] < ZT_IDENTITY_GEN_HASHCASH_FIRST_BYTE_LESS_THAN); } - - unsigned char *sha512digest; + unsigned char *sha512digest,*genmem; }; void Identity::generate() { unsigned char sha512digest[64]; + unsigned char *genmem = new unsigned char[ZT_IDENTITY_GEN_MEMORY]; C25519::Pair kp; do { - kp = C25519::generateSatisfying(_Identity_generate_cond(sha512digest)); + kp = C25519::generateSatisfying(_Identity_generate_cond(sha512digest,genmem)); _address.setTo(sha512digest + 59,ZT_ADDRESS_LENGTH); // last 5 bytes are address } while (_address.isReserved()); @@ -90,6 +90,8 @@ void Identity::generate() if (!_privateKey) _privateKey = new C25519::Private(); *_privateKey = kp.priv; + + delete [] genmem; } bool Identity::locallyValidate() const @@ -98,7 +100,9 @@ bool Identity::locallyValidate() const return false; unsigned char sha512digest[64]; - _computeMemoryHardHash(_publicKey.data,_publicKey.size(),sha512digest); + unsigned char *genmem = new unsigned char[ZT_IDENTITY_GEN_MEMORY]; + _computeMemoryHardHash(_publicKey.data,_publicKey.size(),sha512digest,genmem); + delete [] genmem; unsigned char addrb[5]; _address.copyTo(addrb,5); |