mirror of
https://github.com/zerotier/ZeroTierOne.git
synced 2024-12-20 21:43:08 +00:00
125 lines
4.2 KiB
C++
125 lines
4.2 KiB
C++
/*
|
|
* Copyright (c)2019 ZeroTier, Inc.
|
|
*
|
|
* Use of this software is governed by the Business Source License included
|
|
* in the LICENSE.TXT file in the project's root directory.
|
|
*
|
|
* Change Date: 2023-01-01
|
|
*
|
|
* On the date above, in accordance with the Business Source License, use
|
|
* of this software will be governed by version 2.0 of the Apache License.
|
|
*/
|
|
/****/
|
|
|
|
#ifndef ZT_C25519_HPP
|
|
#define ZT_C25519_HPP
|
|
|
|
#include "Utils.hpp"
|
|
|
|
namespace ZeroTier {
|
|
|
|
#define ZT_C25519_PUBLIC_KEY_LEN 64
|
|
#define ZT_C25519_PRIVATE_KEY_LEN 64
|
|
#define ZT_C25519_SIGNATURE_LEN 96
|
|
#define ZT_C25519_SHARED_KEY_LEN 32
|
|
|
|
/**
|
|
* A combined Curve25519 ECDH and Ed25519 signature engine
|
|
*/
|
|
class C25519
|
|
{
|
|
public:
|
|
/**
|
|
* Generate a C25519 elliptic curve key pair
|
|
*/
|
|
static ZT_ALWAYS_INLINE void generate(uint8_t pub[ZT_C25519_PUBLIC_KEY_LEN],uint8_t priv[ZT_C25519_PRIVATE_KEY_LEN])
|
|
{
|
|
Utils::getSecureRandom(priv,ZT_C25519_PRIVATE_KEY_LEN);
|
|
_calcPubDH(pub,priv);
|
|
_calcPubED(pub,priv);
|
|
}
|
|
|
|
/**
|
|
* Generate a key pair satisfying a condition
|
|
*
|
|
* This begins with a random keypair from a random secret key and then
|
|
* iteratively increments the random secret until cond(kp) returns true.
|
|
* This is used to compute key pairs in which the public key, its hash
|
|
* or some other aspect of it satisfies some condition, such as for a
|
|
* hashcash criteria.
|
|
*
|
|
* @param cond Condition function or function object
|
|
* @return Key pair where cond(kp) returns true
|
|
* @tparam F Type of 'cond'
|
|
*/
|
|
template<typename F>
|
|
static ZT_ALWAYS_INLINE void generateSatisfying(F cond,uint8_t pub[ZT_C25519_PUBLIC_KEY_LEN],uint8_t priv[ZT_C25519_PRIVATE_KEY_LEN])
|
|
{
|
|
Utils::getSecureRandom(priv,ZT_C25519_PRIVATE_KEY_LEN);
|
|
_calcPubED(pub,priv); // do Ed25519 key -- bytes 32-63 of pub and priv
|
|
do {
|
|
++(((uint64_t *)priv)[1]);
|
|
--(((uint64_t *)priv)[2]);
|
|
_calcPubDH(pub,priv); // keep regenerating bytes 0-31 until satisfied
|
|
} while (!cond(pub));
|
|
}
|
|
|
|
/**
|
|
* Perform C25519 ECC key agreement
|
|
*
|
|
* Actual key bytes are generated from one or more SHA-512 digests of
|
|
* the raw result of key agreement.
|
|
*
|
|
* @param mine My private key
|
|
* @param their Their public key
|
|
* @param rawkey Buffer to receive raw (not hashed) agreed upon key
|
|
*/
|
|
static void agree(const uint8_t mine[ZT_C25519_PRIVATE_KEY_LEN],const uint8_t their[ZT_C25519_PUBLIC_KEY_LEN],uint8_t rawkey[32]);
|
|
|
|
/**
|
|
* Sign a message with a sender's key pair
|
|
*
|
|
* This takes the SHA-521 of msg[] and then signs the first 32 bytes of this
|
|
* digest, returning it and the 64-byte ed25519 signature in signature[].
|
|
* This results in a signature that verifies both the signer's authenticity
|
|
* and the integrity of the message.
|
|
*
|
|
* This is based on the original ed25519 code from NaCl and the SUPERCOP
|
|
* cipher benchmark suite, but with the modification that it always
|
|
* produces a signature of fixed 96-byte length based on the hash of an
|
|
* arbitrary-length message.
|
|
*
|
|
* @param myPrivate My private key
|
|
* @param myPublic My public key
|
|
* @param msg Message to sign
|
|
* @param len Length of message in bytes
|
|
* @param signature Buffer to fill with signature -- MUST be 96 bytes in length
|
|
*/
|
|
static void sign(const uint8_t myPrivate[ZT_C25519_PRIVATE_KEY_LEN],const uint8_t myPublic[ZT_C25519_PUBLIC_KEY_LEN],const void *msg,unsigned int len,void *signature);
|
|
|
|
/**
|
|
* Verify a message's signature
|
|
*
|
|
* @param their Public key to verify against
|
|
* @param msg Message to verify signature integrity against
|
|
* @param len Length of message in bytes
|
|
* @param signature Signature bytes
|
|
* @param siglen Length of signature in bytes
|
|
* @return True if signature is valid and the message is authentic and unmodified
|
|
*/
|
|
static bool verify(const uint8_t their[ZT_C25519_PUBLIC_KEY_LEN],const void *msg,unsigned int len,const void *signature,const unsigned int siglen);
|
|
|
|
private:
|
|
// derive first 32 bytes of kp.pub from first 32 bytes of kp.priv
|
|
// this is the ECDH key
|
|
static void _calcPubDH(uint8_t pub[ZT_C25519_PUBLIC_KEY_LEN],const uint8_t priv[ZT_C25519_PRIVATE_KEY_LEN]);
|
|
|
|
// derive 2nd 32 bytes of kp.pub from 2nd 32 bytes of kp.priv
|
|
// this is the Ed25519 sign/verify key
|
|
static void _calcPubED(uint8_t pub[ZT_C25519_PUBLIC_KEY_LEN],const uint8_t priv[ZT_C25519_PRIVATE_KEY_LEN]);
|
|
};
|
|
|
|
} // namespace ZeroTier
|
|
|
|
#endif
|