#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
+#define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util", syscall)
+
#define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util", syscall, filename)
+/**
+ * Log an error message at log-level 'level' that indicates
+ * a failure of the command 'cmd' with the message given
+ * by gcry_strerror(rc).
+ */
+#define LOG_GCRY(level, cmd, rc) do { LOG(level, _("`%s' failed at %s:%d with error: %s\n"), cmd, __FILE__, __LINE__, gcry_strerror(rc)); } while(0);
+
/**
* Name of the directory which stores meta data for pseudonym
*/
* Writes the pseudonym infomation into a file
*
* @param cfg overall configuration
- * @param nsid id of the pseudonym
+ * @param pseudonym id of the pseudonym
* @param name name to set. Must be the non-unique version of it.
* May be NULL, in which case it erases pseudonym's name!
* @param md metadata to set
* Read pseudonym infomation from a file
*
* @param cfg configuration to use
- * @param nsid hash code of a pseudonym
+ * @param pseudonym hash code of a pseudonym
* @param meta meta data to be read from a file
* @param rank rank of a pseudonym
* @param ns_name name of a pseudonym
struct GNUNET_PseudonymHandle
{
/**
- * FIXME.
+ * 256-bit 'd' secret value (mod 'n', where n is 256-bit for NIST P-256).
*/
- char data[42];
+ unsigned char d[256 / 8];
+
+ /**
+ * Public key corresponding to the private key.
+ */
+ struct GNUNET_PseudonymIdentifier public_key;
};
+/**
+ * If target != size, move target bytes to the end of the size-sized
+ * buffer and zero out the first target-size bytes.
+ *
+ * @param buf original buffer
+ * @param size number of bytes in the buffer
+ * @param target target size of the buffer
+ */
+static void
+adjust (unsigned char *buf, size_t size, size_t target)
+{
+ if (size < target)
+ {
+ memmove (&buf[target - size], buf, size);
+ memset (buf, 0, target - size);
+ }
+}
+
+
+/**
+ * Extract values from an S-expression.
+ *
+ * @param array where to store the result(s)
+ * @param sexp S-expression to parse
+ * @param topname top-level name in the S-expression that is of interest
+ * @param elems names of the elements to extract
+ * @return 0 on success
+ */
+static int
+key_from_sexp (gcry_mpi_t * array, gcry_sexp_t sexp, const char *topname,
+ const char *elems)
+{
+ gcry_sexp_t list;
+ gcry_sexp_t l2;
+ const char *s;
+ unsigned int i;
+ unsigned int idx;
+
+ if (! (list = gcry_sexp_find_token (sexp, topname, 0)))
+ return 1;
+ l2 = gcry_sexp_cadr (list);
+ gcry_sexp_release (list);
+ list = l2;
+ if (! list)
+ return 2;
+ idx = 0;
+ for (s = elems; *s; s++, idx++)
+ {
+ if (! (l2 = gcry_sexp_find_token (list, s, 1)))
+ {
+ for (i = 0; i < idx; i++)
+ {
+ gcry_free (array[i]);
+ array[i] = NULL;
+ }
+ gcry_sexp_release (list);
+ return 3; /* required parameter not found */
+ }
+ array[idx] = gcry_sexp_nth_mpi (l2, 1, GCRYMPI_FMT_USG);
+ gcry_sexp_release (l2);
+ if (! array[idx])
+ {
+ for (i = 0; i < idx; i++)
+ {
+ gcry_free (array[i]);
+ array[i] = NULL;
+ }
+ gcry_sexp_release (list);
+ return 4; /* required parameter is invalid */
+ }
+ }
+ gcry_sexp_release (list);
+ return 0;
+}
+
+
/**
* Create a pseudonym.
*
{
struct GNUNET_PseudonymHandle *ph;
ssize_t ret;
+ gcry_sexp_t r_key;
+ gcry_sexp_t params;
+ gcry_error_t rc;
+ gcry_mpi_t skey[2];
+ size_t size;
ph = GNUNET_malloc (sizeof (struct GNUNET_PseudonymHandle));
if ( (NULL != filename) &&
{
ret = GNUNET_DISK_fn_read (filename, ph,
sizeof (struct GNUNET_PseudonymHandle));
+ /* Note: we don't do any validation here, maybe we should? */
if (sizeof (struct GNUNET_PseudonymHandle) == ret)
return ph;
+ }
+ if (0 != (rc = gcry_sexp_build (¶ms, NULL,
+ "(genkey(ecdsa(curve \"NIST P-256\")))")))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
+ return NULL;
}
- GNUNET_break (0); // not implemented...
- gcry_randomize (ph, sizeof (struct GNUNET_PseudonymHandle),
- GCRY_STRONG_RANDOM);
+ if (0 != (rc = gcry_pk_genkey (&r_key, params)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
+ return NULL;
+ }
+ /* NOTE: treating a point as a normal MPI value; hopefully that works... */
+ rc = key_from_sexp (skey, r_key, "private-key", "dq");
+ if (0 != rc)
+ rc = key_from_sexp (skey, r_key, "private-key", "dq");
+ if (0 != rc)
+ rc = key_from_sexp (skey, r_key, "ecc", "dq");
+ gcry_sexp_release (r_key);
+ size = sizeof (ph->d);
+ GNUNET_assert (0 ==
+ gcry_mpi_print (GCRYMPI_FMT_USG, ph->d, size, &size,
+ skey[0]));
+ adjust (ph->d, size, sizeof (ph->d));
+ size = sizeof (ph->public_key.q);
+ GNUNET_assert (0 ==
+ gcry_mpi_print (GCRYMPI_FMT_USG, ph->public_key.q, size, &size,
+ skey[1]));
+ adjust (ph->public_key.q, size, sizeof (ph->public_key.q));
+ gcry_mpi_release (skey[0]);
+ gcry_mpi_release (skey[1]);
if (NULL != filename)
{
ret = GNUNET_DISK_fn_write (filename, ph, sizeof (struct GNUNET_PseudonymHandle),
ph = GNUNET_malloc (sizeof (struct GNUNET_PseudonymHandle));
ret = GNUNET_DISK_fn_read (filename, ph,
sizeof (struct GNUNET_PseudonymHandle));
- if (sizeof (struct GNUNET_PseudonymHandle) == ret)
- return ph;
- GNUNET_free (ph);
- return NULL;
+ if (sizeof (struct GNUNET_PseudonymHandle) != ret)
+ {
+ GNUNET_free (ph);
+ return NULL;
+ }
+ /* Note: we don't do any validation here; maybe we should? */
+ return ph;
}
struct GNUNET_PseudonymHandle *ph;
ph = GNUNET_malloc (sizeof (struct GNUNET_PseudonymHandle));
+ /* FIXME: if we use 'd=0' for the anonymous handle (as per#2564),
+ then I believe the public key should be also zero, as Q=0P=0.
+ However, libgcrypt's point representation is completely internal,
+ and treats a z-coordinate of zero as infinity, so we likely need
+ to set it to (0,0,1) internally --- or actually calculate Q=qP
+ explicitly. Either way, we don't have an API to do so yet :-(.
+ */
GNUNET_break (0);
return ph;
}
}
+/**
+ * Convert the data specified in the given purpose argument to an
+ * S-expression suitable for signature operations.
+ *
+ * @param purpose data to convert
+ * @return converted s-expression
+ */
+static gcry_sexp_t
+data_to_pkcs1 (const struct GNUNET_PseudonymSignaturePurpose *purpose)
+{
+ struct GNUNET_CRYPTO_ShortHashCode hc;
+ size_t bufSize;
+ gcry_sexp_t data;
+
+ GNUNET_CRYPTO_short_hash (purpose, ntohl (purpose->size), &hc);
+#define FORMATSTRING "(4:data(5:flags3:raw)(5:value32:01234567890123456789012345678901))"
+ bufSize = strlen (FORMATSTRING) + 1;
+ {
+ char buff[bufSize];
+
+ memcpy (buff, FORMATSTRING, bufSize);
+ memcpy (&buff
+ [bufSize -
+ strlen
+ ("01234567890123456789012345678901))")
+ - 1], &hc, sizeof (struct GNUNET_CRYPTO_ShortHashCode));
+ GNUNET_assert (0 == gcry_sexp_new (&data, buff, bufSize, 0));
+ }
+#undef FORMATSTRING
+ return data;
+}
+
+
/**
* Cryptographically sign some data with the pseudonym.
*
* @param signing_key modifier to apply to the private key for signing;
* corresponds to 'h' in section 2.3 of #2564.
* @param signature where to store the signature
+ * @return GNUNET_SYSERR on failure
*/
-void
+int
GNUNET_PSEUDONYM_sign (struct GNUNET_PseudonymHandle *ph,
const struct GNUNET_PseudonymSignaturePurpose *purpose,
const struct GNUNET_HashCode *seed,
const struct GNUNET_HashCode *signing_key,
struct GNUNET_PseudonymSignature *signature)
{
- memset (signature, 0, sizeof (struct GNUNET_PseudonymSignature));
- GNUNET_break (0);
+ size_t size;
+ size_t erroff;
+ gcry_mpi_t x;
+ gcry_mpi_t k;
+ gcry_mpi_t h;
+ gcry_mpi_t d;
+ gcry_mpi_t n; /* n from P-256 */
+ gcry_sexp_t spriv;
+ gcry_sexp_t data;
+ gcry_sexp_t result;
+ gcry_mpi_t rs[2];
+ int rc;
+
+ /* get private key 'x' from pseudonym */
+ size = sizeof (ph->d);
+ if (0 != (rc = gcry_mpi_scan (&x, GCRYMPI_FMT_USG,
+ &ph->d,
+ size, &size)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
+ return GNUNET_SYSERR;
+ }
+ /* get 'h' value from signing key */
+ size = sizeof (struct GNUNET_HashCode);
+ if (0 != (rc = gcry_mpi_scan (&h, GCRYMPI_FMT_USG,
+ signing_key,
+ size, &size)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
+ gcry_mpi_release (x);
+ return GNUNET_SYSERR;
+ }
+
+ /* initialize 'n' from P-256; hex copied from libgcrypt code */
+ if (0 != (rc = gcry_mpi_scan (&n, GCRYMPI_FMT_HEX,
+ "0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551", 0, NULL)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
+ gcry_mpi_release (x);
+ gcry_mpi_release (h);
+ return GNUNET_SYSERR;
+ }
+
+ /* calculate d = x + h mod n */
+ d = gcry_mpi_new (256);
+ gcry_mpi_addm (d, x, h, n);
+ gcry_mpi_release (x);
+ gcry_mpi_release (h);
+ gcry_mpi_release (n);
+
+ /* now build sexpression with the signing key;
+ NOTE: libgcrypt docs say that we should specify 'Q', but
+ with the current API we cannot calculate Q=dP, so hopefully
+ libgcrypt will derive it from 'd' for us... */
+ if (0 != (rc = gcry_sexp_build (&spriv, &erroff,
+ "(private-key(ecc(curve \"NIST P-256\")(d %m)))",
+ d)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
+ gcry_mpi_release (d);
+ return GNUNET_SYSERR;
+ }
+ gcry_mpi_release (d);
+ /* prepare data for signing */
+ data = data_to_pkcs1 (purpose);
+
+ /* get 'k' value from seed, if available */
+ if (NULL != seed)
+ {
+ size = sizeof (struct GNUNET_HashCode);
+ if (0 != (rc = gcry_mpi_scan (&k, GCRYMPI_FMT_USG,
+ seed,
+ size, &size)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
+ gcry_mpi_release (x);
+ return GNUNET_SYSERR;
+ }
+ }
+
+ /* actually create signature */
+ /* FIXME: need API to pass 'k' if 'seed' was non-NULL! */
+ if (0 != (rc = gcry_pk_sign (&result, data, spriv)))
+ {
+ LOG (GNUNET_ERROR_TYPE_WARNING,
+ _("ECC signing failed at %s:%d: %s\n"), __FILE__,
+ __LINE__, gcry_strerror (rc));
+ gcry_sexp_release (data);
+ gcry_sexp_release (spriv);
+ if (NULL != seed)
+ gcry_mpi_release (k);
+ memset (signature, 0, sizeof (struct GNUNET_PseudonymSignature));
+ return GNUNET_SYSERR;
+ }
+ if (NULL != seed)
+ gcry_mpi_release (k);
+ gcry_sexp_release (data);
+ gcry_sexp_release (spriv);
+
+ /* extract 'r' and 's' values from sexpression 'result' and store in 'signature';
+ FIXME: libgcrypt does not document format of s-expression returned for ECC
+ signatures; so "ecc" here is just a guess. */
+ if (0 != (rc = key_from_sexp (rs, result, "ecc", "rs")))
+ {
+ GNUNET_break (0);
+ gcry_sexp_release (result);
+ return GNUNET_SYSERR;
+ }
+ gcry_sexp_release (result);
+ size = sizeof (signature->sig_r);
+ if (0 != (rc = gcry_mpi_print (GCRYMPI_FMT_USG, (unsigned char *) signature->sig_r, size,
+ &size, rs[0])))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_print", rc);
+ gcry_mpi_release (rs[0]);
+ gcry_mpi_release (rs[1]);
+ return GNUNET_SYSERR;
+ }
+ gcry_mpi_release (rs[0]);
+ size = sizeof (signature->sig_s);
+ if (0 != (rc = gcry_mpi_print (GCRYMPI_FMT_USG, (unsigned char *) signature->sig_s, size,
+ &size, rs[1])))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_print", rc);
+ gcry_mpi_release (rs[1]);
+ return GNUNET_SYSERR;
+ }
+ gcry_mpi_release (rs[1]);
+ return GNUNET_OK;
}
* Given a pseudonym and a signing key, derive the corresponding public
* key that would be used to verify the resulting signature.
*
- * @param pseudonym the public key (g^x)
+ * @param pseudonym the public key (g^x in DSA, dQ in ECDSA)
* @param signing_key input to derive 'h' (see section 2.4 of #2564)
* @param verification_key resulting public key to verify the signature
* created from the 'ph' of 'pseudonym' and the 'signing_key';
* the value stored here can then be given to GNUNET_PSEUDONYM_verify.
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
*/
-void
+int
GNUNET_PSEUDONYM_derive_verification_key (struct GNUNET_PseudonymIdentifier *pseudonym,
const struct GNUNET_HashCode *signing_key,
struct GNUNET_PseudonymIdentifier *verification_key)
{
struct GNUNET_HashCode hc;
struct GNUNET_HashCode x;
-
+ gcry_mpi_t h;
+ size_t size;
+ int rc;
+
+ /* get 'h' value from signing key */
+ size = sizeof (struct GNUNET_HashCode);
+ if (0 != (rc = gcry_mpi_scan (&h, GCRYMPI_FMT_USG,
+ signing_key,
+ size, &size)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
+ return GNUNET_SYSERR;
+ }
+ /* FIXME: calculate hQ --- need point multiplication API! */
+ gcry_mpi_release (h);
+ /* FIXME: calculate V = dQ + hQ --- need point addition API! */
+
GNUNET_break (0);
GNUNET_CRYPTO_hash (pseudonym, sizeof (*pseudonym), &hc);
GNUNET_CRYPTO_hash_xor (&hc, signing_key, &x);
memset (verification_key, 0, sizeof (struct GNUNET_PseudonymIdentifier));
memcpy (verification_key, &x, GNUNET_MIN (sizeof (x), sizeof (*verification_key)));
+ return GNUNET_OK;
}
const struct GNUNET_PseudonymSignature *signature,
const struct GNUNET_PseudonymIdentifier *verification_key)
{
+#if FUTURE
+ gcry_sexp_t data;
+ gcry_sexp_t sig_sexpr;
+ gcry_sexp_t pk_sexpr;
+ size_t size;
+ gcry_mpi_t r;
+ gcry_mpi_t s;
+ gcry_mpi_t q;
+ size_t erroff;
+ int rc;
+
+ /* build s-expression for signature */
+ size = sizeof (signature->sig_r);
+ if (0 != (rc = gcry_mpi_scan (&r, GCRYMPI_FMT_USG,
+ signature->sig_r, size, &size)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
+ return GNUNET_SYSERR;
+ }
+ size = sizeof (signature->sig_s);
+ if (0 != (rc = gcry_mpi_scan (&s, GCRYMPI_FMT_USG,
+ signature->sig_s, size, &size)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
+ gcry_mpi_release (r);
+ return GNUNET_SYSERR;
+ }
+ if (0 != (rc = gcry_sexp_build (&sig_sexpr, &erroff, "(sig-val(ecc(r %m)(s %m)))",
+ r, s)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
+ gcry_mpi_release (r);
+ gcry_mpi_release (s);
+ return GNUNET_SYSERR;
+ }
+ gcry_mpi_release (r);
+ gcry_mpi_release (s);
+
+ /* build s-expression for data that was signed */
+ data = data_to_pkcs1 (purpose);
+
+ /* build s-expression for public key */
+ /* NOTE: treating a point as a normal MPI value; hopefully that works... */
+ size = sizeof (verification_key->q);
+ if (0 != (rc = gcry_mpi_scan (&q, GCRYMPI_FMT_USG,
+ verification_key->q, size, &size)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
+ gcry_sexp_release (data);
+ gcry_sexp_release (sig_sexpr);
+ return GNUNET_SYSERR;
+ }
+ if (0 != (rc = gcry_sexp_build (&sig_sexpr, &erroff, "(public-key(ecc(curve \"NIST P-256\")(q %m)))",
+ q)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
+ gcry_mpi_release (q);
+ gcry_sexp_release (data);
+ gcry_sexp_release (sig_sexpr);
+ return GNUNET_SYSERR;
+ }
+ gcry_mpi_release (q);
+
+ /* finally, verify the signature */
+ rc = gcry_pk_verify (sig_sexpr, data, pk_sexpr);
+ gcry_sexp_release (sig_sexpr);
+ gcry_sexp_release (data);
+ gcry_sexp_release (pk_sexpr);
+ if (rc)
+ {
+ LOG (GNUNET_ERROR_TYPE_WARNING,
+ _("RSA signature verification failed at %s:%d: %s\n"), __FILE__,
+ __LINE__, gcry_strerror (rc));
+ return GNUNET_SYSERR;
+ }
+#else
GNUNET_break (0);
+#endif
return GNUNET_OK;
}
GNUNET_PSEUDONYM_get_identifier (struct GNUNET_PseudonymHandle *ph,
struct GNUNET_PseudonymIdentifier *pseudonym)
{
- GNUNET_break (0);
- memcpy (pseudonym, ph,
- GNUNET_MIN (sizeof (struct GNUNET_PseudonymIdentifier),
- sizeof (*ph)));
+ memcpy (pseudonym, &ph->public_key,
+ sizeof (struct GNUNET_PseudonymIdentifier));
}
*/
int
GNUNET_PSEUDONYM_remove (const struct GNUNET_CONFIGURATION_Handle *cfg,
- const struct GNUNET_PseudonymIdentifier *id)
+ const struct GNUNET_PseudonymIdentifier *id)
{
char *fn;
int result;
- result = GNUNET_SYSERR;
fn = get_data_filename (cfg, PS_METADATA_DIR, id);
- if (NULL != fn)
- {
- result = UNLINK (fn);
- GNUNET_free (fn);
- }
- return (GNUNET_OK == result ? GNUNET_OK : GNUNET_SYSERR);
+ if (NULL == fn)
+ return GNUNET_SYSERR;
+ result = UNLINK (fn);
+ GNUNET_free (fn);
+ return (0 == result) ? GNUNET_OK : GNUNET_SYSERR;
}
/* end of pseudonym.c */
projects / oweals / gnunet.git / blobdiff