/usr/include/bobcat/diffiehellman is in libbobcat-dev 3.19.01-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 | #ifndef INCLUDED_BOBCAT_DIFFIEHELLMAN_
#define INCLUDED_BOBCAT_DIFFIEHELLMAN_
#include <memory>
#include <iosfwd>
#include <bobcat/bigint>
#include <openssl/dh.h>
namespace FBB
{
class DiffieHellman
{
std::shared_ptr<DH> d_dh;
std::shared_ptr<BIGNUM> d_otherPubKey; // public key of the other party
static char const *s_header;
public:
enum SecretKey
{
DONT_SAVE_SECRET_KEY,
SAVE_SECRET_KEY
};
enum
{
CHECK_FAILS =
~(DH_CHECK_P_NOT_PRIME | DH_CHECK_P_NOT_SAFE_PRIME |
DH_NOT_SUITABLE_GENERATOR | DH_UNABLE_TO_CHECK_GENERATOR)
};
// The initiator calls this constructor, which computes the common
// DH parameters
DiffieHellman(size_t primeLength = 1024, size_t generator = 5,
bool progress = false);
// The initiator saves the public info on basename.pub
// and, by providing 'SAVE_SECRET_KEY, the secret info on
// basename.sec
void save(std::string const &basename, SecretKey action =
DONT_SAVE_SECRET_KEY) const;
// The initiator sends basename.pub to the peer, who reads
// basename.pub using this constructor:
DiffieHellman(std::string const &initiatorPublicFileName);
// Alternatively, use this constructor expecting an istream:
DiffieHellman(std::istream &initiatorPublicStream);
// The peer now saves *his/her* public and (optionally) private
// info: by calling save, providing a basename and optionally a
// SecretKey argument. Next, the peer sends his/her public info
// to the initiator.
// The peer can already now determine the symmetric encryption
// key, since he/she has
// - The DH prime and generator;
// - The initiator's public key;
// - His/her own secret key.
// The key is obtained by calling
std::string key() const;
// The initiator has two options: - After calling save and
// transmitting the public data to the peer the DiffieHellman
// object is kept, and the initiator waits for the peer's public
// key to become available. In that case the initiator's private
// key doesn't have to be saved, and ephemeral DH is
// obtained. After receiving the peer's public parameters the
// initiator calls either of these overloaded versions of key to
// obtain the symmetric key:
std::string key(std::string const &peerPublicFileName);
std::string key(std::istream &peerPublicStream);
// Otherwise the initiator creates another DiffieHellman object,
// using the 4th or 5th constructor, and then calls either of the
// last two key members to obtain the symmetric key.
DiffieHellman(std::string const &initiatorPublicFileName,
std::string const &initiatorPrivateFileName);
// Alternatively, use this constructor expecting istreams:
DiffieHellman(std::istream &initiatorPublicStream,
std::istream &initiatorPrivateStream);
private:
void checkDHparameters();
bool load(std::istream &publicData);
void write(std::ostream &out, BIGNUM const *bn, char *buffer,
uint32_t nBytes) const;
bool read(std::istream &in, BIGNUM **dest);
static void skip(std::istream &in, size_t count);
static void callback(int, int, void *);
// std::string publicKey() const;
// std::string sharedKey(BigInt const &peersPublicKey
// private:
//
// DH *newDH();
};
} // FBB
#endif
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