/*
This file is part of GNUnet.
- Copyright (C) 2012, 2013, 2015 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2012, 2013, 2015 GNUnet e.V.
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
*/
#include "platform.h"
#include <gcrypt.h>
-#include "gnunet_util_lib.h"
+#include "gnunet_crypto_lib.h"
+#include "gnunet_strings_lib.h"
#define EXTRA_CHECKS 0
rc = gcry_sexp_build (&result, NULL,
"(private-key(ecc(curve \"" CURVE "\")"
"(d %b)))",
- (int)sizeof (priv->d), priv->d);
+ (int) sizeof (priv->d), priv->d);
if (0 != rc)
{
LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
gcry_mpi_t d;
int rc;
+ /* NOTE: For libgcrypt >= 1.7, we do not need the 'eddsa' flag here,
+ but should also be harmless. For libgcrypt < 1.7, using 'eddsa'
+ disables an expensive key testing routine. We do not want to run
+ the expensive check for ECDHE, as we generate TONS of keys to
+ use for a very short time. */
if (0 != (rc = gcry_sexp_build (&s_keyparam, NULL,
"(genkey(ecc(curve \"" CURVE "\")"
- "(flags eddsa)))")))
+ "(flags eddsa no-keytest)))")))
{
LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
return NULL;
}
-/**
- * Wait for a short time (we're trying to lock a file or want
- * to give another process a shot at finishing a disk write, etc.).
- * Sleeps for 100ms (as that should be long enough for virtually all
- * modern systems to context switch and allow another process to do
- * some 'real' work).
- */
-static void
-short_wait ()
-{
- struct GNUNET_TIME_Relative timeout;
-
- timeout = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 100);
- (void) GNUNET_NETWORK_socket_select (NULL, NULL, NULL, timeout);
-}
-
-
-/**
- * Create a new private key by reading it from a file. If the
- * files does not exist, create a new key and write it to the
- * file. Caller must free return value. Note that this function
- * can not guarantee that another process might not be trying
- * the same operation on the same file at the same time.
- * If the contents of the file
- * are invalid the old file is deleted and a fresh key is
- * created.
- *
- * @param filename name of file to use to store the key
- * @return new private key, NULL on error (for example,
- * permission denied)
- */
-struct GNUNET_CRYPTO_EddsaPrivateKey *
-GNUNET_CRYPTO_eddsa_key_create_from_file (const char *filename)
-{
- struct GNUNET_CRYPTO_EddsaPrivateKey *priv;
- struct GNUNET_DISK_FileHandle *fd;
- unsigned int cnt;
- int ec;
- uint64_t fs;
-
- if (GNUNET_SYSERR == GNUNET_DISK_directory_create_for_file (filename))
- return NULL;
- while (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- fd = GNUNET_DISK_file_open (filename,
- GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_CREATE
- | GNUNET_DISK_OPEN_FAILIFEXISTS,
- GNUNET_DISK_PERM_USER_READ |
- GNUNET_DISK_PERM_USER_WRITE);
- if (NULL == fd)
- {
- if (EEXIST == errno)
- {
- if (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- /* must exist but not be accessible, fail for good! */
- if (0 != ACCESS (filename, R_OK))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "access", filename);
- else
- GNUNET_break (0); /* what is going on!? */
- return NULL;
- }
- continue;
- }
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
- return NULL;
- }
- cnt = 0;
- while (GNUNET_YES !=
- GNUNET_DISK_file_lock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey),
- GNUNET_YES))
- {
- short_wait ();
- if (0 == ++cnt % 10)
- {
- ec = errno;
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _("Could not acquire lock on file `%s': %s...\n"), filename,
- STRERROR (ec));
- }
- }
- LOG (GNUNET_ERROR_TYPE_INFO,
- _("Creating a new private key. This may take a while.\n"));
- priv = GNUNET_CRYPTO_eddsa_key_create ();
- GNUNET_assert (NULL != priv);
- GNUNET_assert (sizeof (*priv) ==
- GNUNET_DISK_file_write (fd, priv, sizeof (*priv)));
- GNUNET_DISK_file_sync (fd);
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_YES == GNUNET_DISK_file_close (fd));
- return priv;
- }
- /* key file exists already, read it! */
- fd = GNUNET_DISK_file_open (filename, GNUNET_DISK_OPEN_READ,
- GNUNET_DISK_PERM_NONE);
- if (NULL == fd)
- {
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
- return NULL;
- }
- cnt = 0;
- while (1)
- {
- if (GNUNET_YES !=
- GNUNET_DISK_file_lock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey),
- GNUNET_NO))
- {
- if (0 == ++cnt % 60)
- {
- ec = errno;
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _("Could not acquire lock on file `%s': %s...\n"), filename,
- STRERROR (ec));
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _
- ("This may be ok if someone is currently generating a private key.\n"));
- }
- short_wait ();
- continue;
- }
- if (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- /* eh, what!? File we opened is now gone!? */
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "stat", filename);
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_OK == GNUNET_DISK_file_close (fd));
-
- return NULL;
- }
- if (GNUNET_OK != GNUNET_DISK_file_size (filename, &fs, GNUNET_YES, GNUNET_YES))
- fs = 0;
- if (fs < sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey))
- {
- /* maybe we got the read lock before the key generating
- * process had a chance to get the write lock; give it up! */
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- if (0 == ++cnt % 10)
- {
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _("When trying to read key file `%s' I found %u bytes but I need at least %u.\n"),
- filename, (unsigned int) fs,
- (unsigned int) sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey));
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _("This may be ok if someone is currently generating a key.\n"));
- }
- short_wait (); /* wait a bit longer! */
- continue;
- }
- break;
- }
- fs = sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey);
- priv = GNUNET_malloc (fs);
- GNUNET_assert (fs == GNUNET_DISK_file_read (fd, priv, fs));
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_YES == GNUNET_DISK_file_close (fd));
- return priv;
-}
-
-
-/**
- * Create a new private key by reading it from a file. If the
- * files does not exist, create a new key and write it to the
- * file. Caller must free return value. Note that this function
- * can not guarantee that another process might not be trying
- * the same operation on the same file at the same time.
- * If the contents of the file
- * are invalid the old file is deleted and a fresh key is
- * created.
- *
- * @param filename name of file to use to store the key
- * @return new private key, NULL on error (for example,
- * permission denied)
- */
-struct GNUNET_CRYPTO_EcdsaPrivateKey *
-GNUNET_CRYPTO_ecdsa_key_create_from_file (const char *filename)
-{
- struct GNUNET_CRYPTO_EcdsaPrivateKey *priv;
- struct GNUNET_DISK_FileHandle *fd;
- unsigned int cnt;
- int ec;
- uint64_t fs;
-
- if (GNUNET_SYSERR == GNUNET_DISK_directory_create_for_file (filename))
- return NULL;
- while (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- fd = GNUNET_DISK_file_open (filename,
- GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_CREATE
- | GNUNET_DISK_OPEN_FAILIFEXISTS,
- GNUNET_DISK_PERM_USER_READ |
- GNUNET_DISK_PERM_USER_WRITE);
- if (NULL == fd)
- {
- if (EEXIST == errno)
- {
- if (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- /* must exist but not be accessible, fail for good! */
- if (0 != ACCESS (filename, R_OK))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "access", filename);
- else
- GNUNET_break (0); /* what is going on!? */
- return NULL;
- }
- continue;
- }
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
- return NULL;
- }
- cnt = 0;
- while (GNUNET_YES !=
- GNUNET_DISK_file_lock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey),
- GNUNET_YES))
- {
- short_wait ();
- if (0 == ++cnt % 10)
- {
- ec = errno;
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _("Could not acquire lock on file `%s': %s...\n"), filename,
- STRERROR (ec));
- }
- }
- LOG (GNUNET_ERROR_TYPE_INFO,
- _("Creating a new private key. This may take a while.\n"));
- priv = GNUNET_CRYPTO_ecdsa_key_create ();
- GNUNET_assert (NULL != priv);
- GNUNET_assert (sizeof (*priv) ==
- GNUNET_DISK_file_write (fd, priv, sizeof (*priv)));
- GNUNET_DISK_file_sync (fd);
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_YES == GNUNET_DISK_file_close (fd));
- return priv;
- }
- /* key file exists already, read it! */
- fd = GNUNET_DISK_file_open (filename, GNUNET_DISK_OPEN_READ,
- GNUNET_DISK_PERM_NONE);
- if (NULL == fd)
- {
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
- return NULL;
- }
- cnt = 0;
- while (1)
- {
- if (GNUNET_YES !=
- GNUNET_DISK_file_lock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey),
- GNUNET_NO))
- {
- if (0 == ++cnt % 60)
- {
- ec = errno;
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _("Could not acquire lock on file `%s': %s...\n"), filename,
- STRERROR (ec));
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _
- ("This may be ok if someone is currently generating a private key.\n"));
- }
- short_wait ();
- continue;
- }
- if (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- /* eh, what!? File we opened is now gone!? */
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "stat", filename);
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_OK == GNUNET_DISK_file_close (fd));
-
- return NULL;
- }
- if (GNUNET_OK != GNUNET_DISK_file_size (filename, &fs, GNUNET_YES, GNUNET_YES))
- fs = 0;
- if (fs < sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey))
- {
- /* maybe we got the read lock before the key generating
- * process had a chance to get the write lock; give it up! */
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- if (0 == ++cnt % 10)
- {
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _("When trying to read key file `%s' I found %u bytes but I need at least %u.\n"),
- filename, (unsigned int) fs,
- (unsigned int) sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey));
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _("This may be ok if someone is currently generating a key.\n"));
- }
- short_wait (); /* wait a bit longer! */
- continue;
- }
- break;
- }
- fs = sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey);
- priv = GNUNET_malloc (fs);
- GNUNET_assert (fs == GNUNET_DISK_file_read (fd, priv, fs));
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd, 0,
- sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_YES == GNUNET_DISK_file_close (fd));
- return priv;
-}
-
-
-/**
- * Create a new private key by reading our peer's key from
- * the file specified in the configuration.
- *
- * @param cfg the configuration to use
- * @return new private key, NULL on error (for example,
- * permission denied)
- */
-struct GNUNET_CRYPTO_EddsaPrivateKey *
-GNUNET_CRYPTO_eddsa_key_create_from_configuration (const struct GNUNET_CONFIGURATION_Handle *cfg)
-{
- struct GNUNET_CRYPTO_EddsaPrivateKey *priv;
- char *fn;
-
- if (GNUNET_OK !=
- GNUNET_CONFIGURATION_get_value_filename (cfg, "PEER", "PRIVATE_KEY", &fn))
- return NULL;
- priv = GNUNET_CRYPTO_eddsa_key_create_from_file (fn);
- GNUNET_free (fn);
- return priv;
-}
-
-
-/**
- * Setup a key file for a peer given the name of the
- * configuration file (!). This function is used so that
- * at a later point code can be certain that reading a
- * key is fast (for example in time-dependent testcases).
- *
- * @param cfg_name name of the configuration file to use
- */
-void
-GNUNET_CRYPTO_eddsa_setup_key (const char *cfg_name)
-{
- struct GNUNET_CONFIGURATION_Handle *cfg;
- struct GNUNET_CRYPTO_EddsaPrivateKey *priv;
-
- cfg = GNUNET_CONFIGURATION_create ();
- (void) GNUNET_CONFIGURATION_load (cfg, cfg_name);
- priv = GNUNET_CRYPTO_eddsa_key_create_from_configuration (cfg);
- if (NULL != priv)
- GNUNET_free (priv);
- GNUNET_CONFIGURATION_destroy (cfg);
-}
-
-
-/**
- * Retrieve the identity of the host's peer.
- *
- * @param cfg configuration to use
- * @param dst pointer to where to write the peer identity
- * @return #GNUNET_OK on success, #GNUNET_SYSERR if the identity
- * could not be retrieved
- */
-int
-GNUNET_CRYPTO_get_peer_identity (const struct GNUNET_CONFIGURATION_Handle *cfg,
- struct GNUNET_PeerIdentity *dst)
-{
- struct GNUNET_CRYPTO_EddsaPrivateKey *priv;
-
- if (NULL == (priv = GNUNET_CRYPTO_eddsa_key_create_from_configuration (cfg)))
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _("Could not load peer's private key\n"));
- return GNUNET_SYSERR;
- }
- GNUNET_CRYPTO_eddsa_key_get_public (priv, &dst->public_key);
- GNUNET_free (priv);
- return GNUNET_OK;
-}
-
-
/**
* Compare two Peer Identities.
*
/* build s-expression for signature */
if (0 != (rc = gcry_sexp_build (&sig_sexpr, NULL,
"(sig-val(ecdsa(r %b)(s %b)))",
- (int)sizeof (sig->r), sig->r,
- (int)sizeof (sig->s), sig->s)))
+ (int) sizeof (sig->r), sig->r,
+ (int) sizeof (sig->s), sig->s)))
{
LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
return GNUNET_SYSERR;
}
data = data_to_ecdsa_value (validate);
if (0 != (rc = gcry_sexp_build (&pub_sexpr, NULL,
- "(public-key(ecc(curve " CURVE ")(q %b)))",
- (int)sizeof (pub->q_y), pub->q_y)))
+ "(public-key(ecc(curve " CURVE ")(q %b)))",
+ (int) sizeof (pub->q_y), pub->q_y)))
{
gcry_sexp_release (data);
gcry_sexp_release (sig_sexpr);
{
gcry_mpi_t h;
struct GNUNET_HashCode hc;
+ static const char *const salt = "key-derivation";
GNUNET_CRYPTO_kdf (&hc, sizeof (hc),
- "key-derivation", strlen ("key-derivation"),
+ salt, strlen (salt),
pub, sizeof (*pub),
label, strlen (label),
context, strlen (context),
return GNUNET_OK;
}
+/**
+ * @ingroup crypto
+ * Derive key material from a ECDH public key and a private ECDSA key.
+ * Dual to #GNUNET_CRRYPTO_ecdh_eddsa.
+ *
+ * @param priv private key from ECDSA to use for the ECDH (x)
+ * @param pub public key to use for the ECDH (yG)
+ * @param key_material where to write the key material H(h(x)yG)
+ * @return #GNUNET_SYSERR on error, #GNUNET_OK on success
+ */
+int
+GNUNET_CRYPTO_ecdsa_ecdh (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv,
+ const struct GNUNET_CRYPTO_EcdhePublicKey *pub,
+ struct GNUNET_HashCode *key_material)
+{
+ gcry_mpi_point_t result;
+ gcry_mpi_point_t q;
+ gcry_mpi_t d;
+ gcry_ctx_t ctx;
+ gcry_sexp_t pub_sexpr;
+ gcry_mpi_t result_x;
+ unsigned char xbuf[256 / 8];
+ size_t rsize;
+
+ /* first, extract the q = dP value from the public key */
+ if (0 != gcry_sexp_build (&pub_sexpr, NULL,
+ "(public-key(ecc(curve " CURVE ")(q %b)))",
+ (int)sizeof (pub->q_y), pub->q_y))
+ return GNUNET_SYSERR;
+ GNUNET_assert (0 == gcry_mpi_ec_new (&ctx, pub_sexpr, NULL));
+ gcry_sexp_release (pub_sexpr);
+ q = gcry_mpi_ec_get_point ("q", ctx, 0);
+
+ /* second, extract the d value from our private key */
+ GNUNET_CRYPTO_mpi_scan_unsigned (&d, priv->d, sizeof (priv->d));
+
+ /* then call the 'multiply' function, to compute the product */
+ result = gcry_mpi_point_new (0);
+ gcry_mpi_ec_mul (result, d, q, ctx);
+ gcry_mpi_point_release (q);
+ gcry_mpi_release (d);
+
+ /* finally, convert point to string for hashing */
+ result_x = gcry_mpi_new (256);
+ if (gcry_mpi_ec_get_affine (result_x, NULL, result, ctx))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "get_affine failed", 0);
+ gcry_mpi_point_release (result);
+ gcry_ctx_release (ctx);
+ return GNUNET_SYSERR;
+ }
+ gcry_mpi_point_release (result);
+ gcry_ctx_release (ctx);
+
+ rsize = sizeof (xbuf);
+ GNUNET_assert (! gcry_mpi_get_flag (result_x, GCRYMPI_FLAG_OPAQUE));
+ /* result_x can be negative here, so we do not use 'GNUNET_CRYPTO_mpi_print_unsigned'
+ as that does not include the sign bit; x should be a 255-bit
+ value, so with the sign it should fit snugly into the 256-bit
+ xbuf */
+ GNUNET_assert (0 ==
+ gcry_mpi_print (GCRYMPI_FMT_STD, xbuf, rsize, &rsize,
+ result_x));
+ GNUNET_CRYPTO_hash (xbuf,
+ rsize,
+ key_material);
+ gcry_mpi_release (result_x);
+ return GNUNET_OK;
+}
+
+
/**
* @ingroup crypto
return GNUNET_OK;
}
-
+/**
+ * @ingroup crypto
+ * Derive key material from a ECDSA public key and a private ECDH key.
+ * Dual to #GNUNET_CRRYPTO_eddsa_ecdh.
+ *
+ * @param priv private key to use for the ECDH (y)
+ * @param pub public key from ECDSA to use for the ECDH (X=h(x)G)
+ * @param key_material where to write the key material H(yX)=H(h(x)yG)
+ * @return #GNUNET_SYSERR on error, #GNUNET_OK on success
+ */
+int
+GNUNET_CRYPTO_ecdh_ecdsa (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv,
+ const struct GNUNET_CRYPTO_EcdsaPublicKey *pub,
+ struct GNUNET_HashCode *key_material)
+{
+ return GNUNET_CRYPTO_ecdh_eddsa (priv,
+ (const struct GNUNET_CRYPTO_EddsaPublicKey *)pub,
+ key_material);
+}
/* end of crypto_ecc.c */
projects / oweals / gnunet.git / blobdiff