secretsharing_api.c File Reference

#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_secretsharing_service.h"
#include "secretsharing.h"
#include <gcrypt.h>

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Data Structures
struct	GNUNET_SECRETSHARING_Session
	Session that will eventually establish a shared secred between the involved peers and allow encryption and cooperative decryption. More...
struct	GNUNET_SECRETSHARING_DecryptionHandle
	Handle to cancel a cooperative decryption operation. More...

Macros
#define	LOG(kind, ...)   GNUNET_log_from (kind, "secretsharing-api", __VA_ARGS__)

Functions
static void	ensure_elgamal_initialized (void)
	Function to initialize elgamal_q, elgamal_p and elgamal_g. More...
static void	handle_session_client_error (void *cls, enum GNUNET_MQ_Error error)
	Callback invoked when there is an error communicating with the service. More...
static void	handle_decrypt_client_error (void *cls, enum GNUNET_MQ_Error error)
	Callback invoked when there is an error communicating with the service. More...
static int	check_secret_ready (void *cls, const struct GNUNET_SECRETSHARING_SecretReadyMessage *m)
	Handler invoked with the final result message from secret sharing. More...
static void	handle_secret_ready (void *cls, const struct GNUNET_SECRETSHARING_SecretReadyMessage *m)
	Handler invoked with the final result message from secret sharing. More...
void	GNUNET_SECRETSHARING_session_destroy (struct GNUNET_SECRETSHARING_Session *s)
	Destroy a secret sharing session. More...
struct GNUNET_SECRETSHARING_Session *	GNUNET_SECRETSHARING_create_session (const struct GNUNET_CONFIGURATION_Handle *cfg, unsigned int num_peers, const struct GNUNET_PeerIdentity *peers, const struct GNUNET_HashCode *session_id, struct GNUNET_TIME_Absolute start, struct GNUNET_TIME_Absolute deadline, unsigned int threshold, GNUNET_SECRETSHARING_SecretReadyCallback cb, void *cls)
	Create a session that will eventually establish a shared secret with the other peers. More...
static void	handle_decrypt_done (void *cls, const struct GNUNET_SECRETSHARING_DecryptResponseMessage *m)
struct GNUNET_SECRETSHARING_DecryptionHandle *	GNUNET_SECRETSHARING_decrypt (const struct GNUNET_CONFIGURATION_Handle *cfg, struct GNUNET_SECRETSHARING_Share *share, const struct GNUNET_SECRETSHARING_Ciphertext *ciphertext, struct GNUNET_TIME_Absolute start, struct GNUNET_TIME_Absolute deadline, GNUNET_SECRETSHARING_DecryptCallback decrypt_cb, void *decrypt_cb_cls)
	Publish the given ciphertext for decryption. More...
int	GNUNET_SECRETSHARING_plaintext_generate_i (struct GNUNET_SECRETSHARING_Plaintext *plaintext, int64_t exponent)
int	GNUNET_SECRETSHARING_encrypt (const struct GNUNET_SECRETSHARING_PublicKey *public_key, const struct GNUNET_SECRETSHARING_Plaintext *plaintext, struct GNUNET_SECRETSHARING_Ciphertext *result_ciphertext)
	Encrypt a value. More...
void	GNUNET_SECRETSHARING_decrypt_cancel (struct GNUNET_SECRETSHARING_DecryptionHandle *dh)
	Cancel a decryption. More...

Variables
static gcry_mpi_t	elgamal_q
	The ElGamal prime field order as libgcrypt mpi. More...
static gcry_mpi_t	elgamal_p
	Modulus of the prime field used for ElGamal. More...
static gcry_mpi_t	elgamal_g
	Generator for prime field of order 'elgamal_q'. More...

Detailed Description

Author

Florian Dold

Definition in file secretsharing_api.c.

Macro Definition Documentation

LOG

#define LOG	(		kind,
			...
	)		GNUNET_log_from (kind, "secretsharing-api", __VA_ARGS__)

Definition at line 33 of file secretsharing_api.c.

Function Documentation

ensure_elgamal_initialized()

static void ensure_elgamal_initialized ( void  )

static

Function to initialize elgamal_q, elgamal_p and elgamal_g.

Definition at line 103 of file secretsharing_api.c.

{
  if (NULL != elgamal_q)
    return; /* looks like crypto is already initialized */
 
  GNUNET_assert (0 == gcry_mpi_scan (&elgamal_q, GCRYMPI_FMT_HEX,
                                     GNUNET_SECRETSHARING_ELGAMAL_Q_HEX, 0,
                                     NULL));
  GNUNET_assert (0 == gcry_mpi_scan (&elgamal_p, GCRYMPI_FMT_HEX,
                                     GNUNET_SECRETSHARING_ELGAMAL_P_HEX, 0,
                                     NULL));
  GNUNET_assert (0 == gcry_mpi_scan (&elgamal_g, GCRYMPI_FMT_HEX,
                                     GNUNET_SECRETSHARING_ELGAMAL_G_HEX, 0,
                                     NULL));
}

References elgamal_g, elgamal_p, elgamal_q, GNUNET_assert, GNUNET_SECRETSHARING_ELGAMAL_G_HEX, GNUNET_SECRETSHARING_ELGAMAL_P_HEX, and GNUNET_SECRETSHARING_ELGAMAL_Q_HEX.

Referenced by GNUNET_SECRETSHARING_encrypt(), and GNUNET_SECRETSHARING_plaintext_generate_i().

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handle_session_client_error()

static void handle_session_client_error ( void *  cls, enum GNUNET_MQ_Error  error  )

static

Callback invoked when there is an error communicating with the service.

Notifies the application about the error.

Parameters

cls	the struct GNUNET_SECRETSHARING_Session
error	error code

Definition at line 128 of file secretsharing_api.c.

{
  struct GNUNET_SECRETSHARING_Session *s = cls;
 
  s->secret_ready_cb (s->secret_ready_cls, NULL, NULL, 0, NULL);
  GNUNET_SECRETSHARING_session_destroy (s);
}

References GNUNET_SECRETSHARING_session_destroy(), GNUNET_SECRETSHARING_Session::secret_ready_cb, and GNUNET_SECRETSHARING_Session::secret_ready_cls.

Referenced by GNUNET_SECRETSHARING_create_session().

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handle_decrypt_client_error()

static void handle_decrypt_client_error ( void *  cls, enum GNUNET_MQ_Error  error  )

static

Callback invoked when there is an error communicating with the service.

Notifies the application about the error.

Parameters

cls	the struct GNUNET_SECRETSHARING_DecryptionHandle
error	error code

Definition at line 146 of file secretsharing_api.c.

{
  struct GNUNET_SECRETSHARING_DecryptionHandle *dh = cls;
 
  dh->decrypt_cb (dh->decrypt_cls, NULL);
  GNUNET_SECRETSHARING_decrypt_cancel (dh);
}

References GNUNET_SECRETSHARING_DecryptionHandle::decrypt_cb, GNUNET_SECRETSHARING_DecryptionHandle::decrypt_cls, and GNUNET_SECRETSHARING_decrypt_cancel().

Referenced by GNUNET_SECRETSHARING_decrypt().

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check_secret_ready()

static int check_secret_ready ( void *  cls, const struct GNUNET_SECRETSHARING_SecretReadyMessage *  m  )

static

Handler invoked with the final result message from secret sharing.

Decodes the message and passes the result to the application.

Parameters

cls	the struct GNUNET_SECRETSHARING_Session
m	message with the result

Definition at line 165 of file secretsharing_api.c.

{
  /* FIXME: actually check m is well-formed here! */
  return GNUNET_OK;
}

References GNUNET_OK.

handle_secret_ready()

static void handle_secret_ready ( void *  cls, const struct GNUNET_SECRETSHARING_SecretReadyMessage *  m  )

static

Handler invoked with the final result message from secret sharing.

Decodes the message and passes the result to the application.

Parameters

cls	the struct GNUNET_SECRETSHARING_Session
m	message with the result

Definition at line 182 of file secretsharing_api.c.

{
  struct GNUNET_SECRETSHARING_Session *s = cls;
  struct GNUNET_SECRETSHARING_Share *share;
  size_t share_size;
 
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Got secret ready message of size %u\n",
       ntohs (m->header.size));
  share_size = ntohs (m->header.size) - sizeof(struct
                                               GNUNET_SECRETSHARING_SecretReadyMessage);
 
  share = GNUNET_SECRETSHARING_share_read (&m[1],
                                           share_size,
                                           NULL);
  GNUNET_assert (NULL != share);  // FIXME: this can fail!
  // should have been checked in #check_secret_ready!
  // FIXME: below we never check &m[1] is valid!
  // FIXME: do we leak 'share' here?
  s->secret_ready_cb (s->secret_ready_cls,
                      share, /* FIXME */
                      &share->public_key,
                      share->num_peers,
                      (const struct GNUNET_PeerIdentity *) &m[1]);
 
  GNUNET_SECRETSHARING_session_destroy (s);
}

References GNUNET_assert, GNUNET_ERROR_TYPE_DEBUG, GNUNET_SECRETSHARING_session_destroy(), GNUNET_SECRETSHARING_share_read(), LOG, m, GNUNET_SECRETSHARING_Share::num_peers, GNUNET_SECRETSHARING_Share::public_key, GNUNET_SECRETSHARING_Session::secret_ready_cb, and GNUNET_SECRETSHARING_Session::secret_ready_cls.

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handle_decrypt_done()

static void handle_decrypt_done ( void *  cls, const struct GNUNET_SECRETSHARING_DecryptResponseMessage *  m  )

static

Definition at line 303 of file secretsharing_api.c.

{
  struct GNUNET_SECRETSHARING_DecryptionHandle *dh = cls;
  const struct GNUNET_SECRETSHARING_Plaintext *plaintext;
 
  if (m->success == 0)
    plaintext = NULL;
  else
    plaintext = (void *) &m->plaintext;
  dh->decrypt_cb (dh->decrypt_cls, plaintext);
  GNUNET_SECRETSHARING_decrypt_cancel (dh);
}

References GNUNET_SECRETSHARING_DecryptionHandle::decrypt_cb, GNUNET_SECRETSHARING_DecryptionHandle::decrypt_cls, GNUNET_SECRETSHARING_decrypt_cancel(), and m.

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Variable Documentation

elgamal_q

gcry_mpi_t elgamal_q

static

The ElGamal prime field order as libgcrypt mpi.

Initialized in init_crypto_constants.

Definition at line 84 of file secretsharing_api.c.

Referenced by ensure_elgamal_initialized(), and GNUNET_SECRETSHARING_encrypt().

elgamal_p

gcry_mpi_t elgamal_p

static

Modulus of the prime field used for ElGamal.

Initialized in init_crypto_constants.

Definition at line 90 of file secretsharing_api.c.

Referenced by ensure_elgamal_initialized(), GNUNET_SECRETSHARING_encrypt(), and GNUNET_SECRETSHARING_plaintext_generate_i().

elgamal_g

gcry_mpi_t elgamal_g

static

Generator for prime field of order 'elgamal_q'.

Initialized in init_crypto_constants.

Definition at line 96 of file secretsharing_api.c.

Referenced by ensure_elgamal_initialized(), GNUNET_SECRETSHARING_encrypt(), and GNUNET_SECRETSHARING_plaintext_generate_i().